FLAME RETARDANT, COMPOSITE FLAME RETARDANT, FLAME RETARDANT ANTISTATIC COMPOSITION AND FLAME RESISTANT METHOD

Abstract

The present invention refers to a flame retardant comprising a complex formed by phosphine oxide and transition metal salt, wherein has good flame retardant property. The present invention also refers to a composite flame retardant and flame retardant antistatic composition, wherein composite flame retardant comprise the flame retardant and the inorganic flame retardant component as described above, which has an enhanced flame retardant effect; said flame retardant antistatic composition, comprising above described flame retardant or composite flame retardant and carbon nanofiber antistatic agent, wherein carbon nanofiber antistatic agent could have interaction with flame retardant, effectively reducing the amount of flame retardant, and the combination with the flame retardant without the adverse effect of each other which result in negative performance of each other, does not influence the subsequent foaming process and the foam structure and physical properties. The present invention also further refers to a flame resistant method, which adds the abovementioned flame retardant, composite flame retardant or flame retardant antistatic composition into the material, so that said material has flame retardance or flame retardance and antistatic, and has excellent mechanical properties.

Claims

1. A flame retardant, comprises a complex formed by phosphine oxide and transition metal salt.

2. The flame retardant according to claim 1, wherein said phosphine oxide has the following molecular structural formula (I): ##STR00004## wherein, R.sub.1, R.sub.2 and R.sub.3 are identical to or different from one another, and are each independently selected from C.sub.1-C.sub.18 straight chain alkyl, C.sub.3-C.sub.18 branched alkyl, C.sub.1-C.sub.18 straight chain alkoxy, C.sub.3-C.sub.18 branched alkoxy, C.sub.6-C.sub.20 substituted or unsubstituted aryl, and C.sub.6-C.sub.20 substituted or unsubstituted aryloxy.

3. The flame retardant according to claim 2, wherein R.sub.1, R.sub.2 and R.sub.3 are each independently selected from C.sub.4-C.sub.18 straight chain or branched alkyl, C.sub.6-C.sub.18 aryl having 1 or 2 carbocycles; preferably selected from the C.sub.6-C.sub.12 straight chain or branched straight chain alkyl having 6 or more carbon atoms in the main carbon chain and substituted or unsubstituted phenyl.

4. The flame retardant according to claim 1, wherein said phosphine oxide can be at least one selected from triphenylphosphine oxide, bis (4-hydroxyphenyl) phenylphosphine oxide, bis (4-carboxyphenyl) phenylphosphine oxide, trihexylphosphine oxide, tridecylphosphine oxide, tributylphosphine oxide, trioctylphosphine oxide, tributyl phosphate and dibutylbutylphosphate.

5. The flame retardant according to claim 1, wherein said transition metal salt can be transition metal organic salt and/or a transition metal inorganic salt, preferably at least one of transition metal's nitrate, sulfate, formate, acetate and oxalate.

6. The flame retardant according to claim 5, wherein said transition metal is preferably metal elements of group VIII, more preferably cobalt and/or nickel.

7. The flame retardant according to claim 1 wherein the preparation step of said complex comprises: the phosphine oxide of 1 to 10 parts by weight and the transition metal of 3 to 15 parts by weight are stirred and mixed in an organic solvent, then heated with microwave, supercritical dried to obtain said complex; said organic solvent is preferably at least one of ethanol, acetone, pyridine, tetrahydrofuran and DMF.

8. A composite flame retardant, comprises the flame retardant according to claim 1 and an inorganic flame retardant component, preferably the weight ratio of said complex to said inorganic flame retardant component is (1-5):1, preferably (2.5-3.5):1.

9. The composite flame retardant according to claim 8, wherein said inorganic flame retardant component is selected from group IIA and IIIA metal hydroxides, preferably at least one selected from magnesium hydroxide and aluminum hydroxide.

10. A flame retardant antistatic composition, comprising the flame retardant according to claim 1, and a carbon nanofiber antistatic agent, preferably said carbon nanofiber contains transition metal of 1 wt % to 5 wt %.

11. The flame retardant antistatic composition according to claim 10, wherein the preparation step of said carbon nanofiber comprises subjecting a carbon source by acid treatment, then forming a complex with the transition metal catalyst, subjecting said complex by carbonization treatment.

12. The flame retardant antistatic composition according to claim 11, wherein said carbon source is preferably at least one of carbon asphalt, petroleum asphalt, coal tar pitch, coal tar, natural graphite, artificial graphite, bamboo charcoal, carbon black, activated carbon and graphene; preferably said carbon source with carbon content of 80 wt % or more; more preferably said carbon source is at least one of coal tar pitch, petroleum pitch and bamboo charcoal has a carbon content of 80 wt % or more.

13. The flame retardant antistatic composition according to claim 11 wherein said transition metal catalyst is preferably at least one of chloride, sulfate, nitrate, acetate and cyclopentadienyl compound of the transition metal; said transition metal is preferably at least one of ferrum, cobalt, nickel and chromium; preferably the weight ratio of the transition metal atom to the carbon source in metal catalysts is (35-70):100.

14. The flame retardant antistatic composition according to claim 11, wherein said carbonization reaction is allowed to proceed for 0.5-5 hours at 800-1200° C. under the protection of inert gas.

15. A flame resistant method, comprising adding said flame retardant according to claim 1 into the material to impart said material have flame retardancy.

16. The method according to claim 15, wherein said material is polymer material, preferably thermoplastic resin, comprising one or more of polyolefin base resin, polylactic acid base resin, polyurethane base resin, polyester base resin and polyamide base resin; preferably said thermoplastic resin is selected one or more from polyethylene base resin, polypropylene base resin, polybutylene base resin, polyurethane base resin, polylactic acid base resin, polyethylene terephthalate base resin, polybutylene terephthalate base resin, polybutylene succinate base resin and nylon 6 base resin, more preferably polypropylene base resin, more further preferably expanded polyethylene beads and/or expanded polypropylene beads.

17. A flame retardant antistatic composition, comprising the composite flame retardant according to claim 8, and a carbon nanofiber antistatic agent, preferably said carbon nanofiber contains transition metal of 1 wt % to 5 wt %.

18. A flame resistant method, comprising adding said composite flame retardant according to claim 8 into the material to impart said material have flame retardancy.

19. A flame resistant method, comprising adding said flame retardant antistatic composition according to claim 10 into the material to impart said material have flame retardancy.

Description

DESCRIPTION OF THE DRAWINGS

[0149] The invention will now be described in further detail with reference to the accompanying drawings, herein, the same parts are denoted by the same reference numerals in the drawings.

[0150] FIG. 1 shows the infrared spectrum of phosphine oxide and Co (OPPh.sub.3).sub.2(NO.sub.3).sub.2;

[0151] FIG. 2 shows the microstructure of electron microscopy of Co (OPPh.sub.3).sub.2(NO.sub.3).sub.2;

[0152] FIG. 3 shows the microstructure of electron microscopy of carbon nanofibers;

[0153] FIG. 4 shows the surface electron microscopy of the flame retardant antistatic expanded polypropylene beads prepared in example 1;

[0154] FIG. 5 shows the sectional electron microscopy of the flame retardant antistatic expanded polypropylene beads prepared in example 1;

[0155] FIG. 6 shows the surface electron microscopy of the expanded polypropylene beads prepared in comparative example 1;

[0156] FIG. 7 shows the sectional electron microscopy of the expanded polypropylene beads prepared in comparative example 1.

SPECIFIC EMBODIMENTS

[0157] The present invention is further described by reference to the following examples, but it should be noted that the present invention is not limited to these examples.

[0158] The raw materials in the following examples and comparative examples include the following. [0159] General polypropylene base resin: China Petroleum & Chemical Corporation QiluBranch, grade EPS30R; [0160] Polyethylene base resin: China Petroleum & Chemical Corporation Yangtze Branch, grade 7042; [0161] Polyethylene base resin: China Petroleum & Chemical Corporation Yanshan Branch, grade LD100ac; [0162] Polyethylene base resin: China Petroleum & Chemical Corporation Beijing Chemical Industry Research Institute, grade HPE1, HPE2; [0163] Polylactic acid base resin: Natureworks; [0164] TPU base resin: BASF; [0165] PBT base resin: Chi Mei Chemical; [0166] PET base resin: Japan Toray; [0167] PA6 base resin: BASF; [0168] PBS base resin: China Petroleum & Chemical Corporation Beijing Chemical Industry Research Institute; [0169] Kaolin: Braun, ACROS, analytical reagent; [0170] Triphenylphosphine oxide: Braun, ACROS, analytical reagent; [0171] Cobalt nitrate: Braun, ACROS, analytical reagent; [0172] Nickel nitrate: Braun, ACROS, analytical reagent; [0173] Coal asphalt: Institute of Coal Chemistry Chinese Academy of Science(Shanxi), the carbon content higher than 80 wt %, industrial grade; [0174] Petroleum asphalt: Sinopec, carbon content higher than 80 wt %, industrial grade; [0175] Bamboo charcoal: Institute of Coal Chemistry Chinese Academy of Science (Shanxi), carbon content higher than 80 wt %, industrial grade; [0176] Magnesium hydroxide: Braun, ACROS, analytical reagent; [0177] Aluminum hydroxide: Braun, ACROS, analytical reagent; [0178] Ethanol: Braun, ACROS, analytical reagent; [0179] Sodium Dodecyl Benzene Sulfonate: Tianjin Guangfu Fine Chemical Research Institute, analytical reagent; [0180] Aluminum sulfate: Tianjin Guangfu Technology Development Co., Ltd., analytical reagent; [0181] Zinc borate: Tianjin Guangfu Fine Chemical Research Institute, analytical reagent; [0182] Carbon nanofibers: Institute of Coal Chemistry, Chinese Academy of Science (Shanxi), purity higher than 80 wt %, industrial grade; [0183] Antistatic agent Atmer129: Croda company, industrial grade; [0184] Trioctylphosphine oxide, trihexylphosphine oxide, tridecylphosphine oxide, tridecylphosphine oxide, tributyl phosphate and dibutyl butylphosphonate are prepared in a conventional known production process.

[0185] Other used raw materials are commercially available.

[0186] The production and test apparatus and equipment used in the following Examples and Comparative Examples include the following. [0187] Underwater pelletizing system: Labline 1000, Germany BKG company; [0188] Melt Tensile Tester: Rheotens71.97, Germany Goettfert; [0189] Density tester: CPA225D, Density accessories YDK01, Germany Satorius company; [0190] Molding Machine: Germany Kurtz Ersa Company Kurtz T-Line; [0191] Universal Material Testing Machine: 5967, the United Kingdom Instron; [0192] Oxygen Index Instrument: 6448, Italy ceast company; [0193] Cone calorimeter: FTT200, British FTT company; [0194] Surface Resistance Meter: 4339B, the United States Agilent company; [0195] Infrared Spectrometer: Nicolet 6700, the United States Thermal company; [0196] Scanning Electron Microscope: SL-30, US FEI Corporation.

[0197] The relevant data of polymer in the examples are obtained according to the following test method.

[0198] (1) The content of xylene solubles at the room temperature and the content of the ethylene in the xylene solubles at the room temperature (i.e., characterization of the content of the rubber phase and the content of ethylene in the rubber phase) are measured by CRYSTEX method, using CRYST-EX manufactured by Spain Polymer Char Company, (CRYST-EX EQUIPMENT, IR4+ detector), selected a series of samples having different content of xylene solubles at the room temperature as standard samples for calibration, the content of standard xylene solubles at room temperature is measured according to ASTM D5492.

[0199] The infrared detector provided by the instrument itself can test the weight content of propylene in the soluble matter, and used to characterize the content of ethylene in the xylene solubles at room temperature (the content of ethylene in the rubber phase)=100%−the content of propylene by weight.

[0200] (2) The tensile strength of the resin is measured according to GB/T 1040.2 (corresponding to ISO 527).

[0201] (3) Melt Mass Flow Rate MFR (also known as melt index): Measured at 230° C. under a load of 2.16 kg by using the CEAST 7026 Melt Indexer according to the method described in ASTM D1238.

[0202] (4) Flexural modulus: Measured according to the method described in GB/T 9341 (corresponding to ISO 178).

[0203] (5) Impact strength of notched simple beam: Measured according to the method described in GB/T 1043.1 (corresponding to ISO179).

[0204] (6) The content of ethylene: Measured by infrared spectroscopy (IR) method, wherein sample is calibrated by nuclear magnetic resonance method. The nuclear magnetic resonance method is measured by using the Swiss Bruker company AVANCE III 400 MHz nuclear magnetic resonance spectroscopy (NMR), a 10 mm probe. The solvent is 1,2-dichlorobenzene-d4, and about 250 mg sample is placed in 2.5 mL deuterated solvent, heated and dissolved in a 140° C. oil bath to form a homogeneous solution. Collecting .sup.13C-NMR, probe temperature 125° C., using 90° pulse, sampling time AQ is 5 seconds, the delay time D1 is 10 seconds, the number of scan times more than 5000 times. Other operations, peak identification and other are carried out as the commonly NMR experimental requirements.

[0205] (7) Polydispersity index of relative molecular mass (PI): The resin sample is molded to 2 mm sheet at 200° C., and subjected to dynamic frequency scanning at 190° C. under nitrogen protection by using ARES (Advanced Rheometer Extension System) rheometer from Rheometric Scientific Inc., use the parallel plate fixture, determine the appropriate strain amplitude to ensure that the experiment is carried out in the straight chain region, storage modulus (G′), loss modulus (G″) etc. of the sample are measured with frequency change.

[0206] The polydispersity index of relative molecular mass PI=10.sup.5/G, where G (unit: Pa) is the modulus value at the intersection of the G′—frequency curve and the G″—frequency curve.

[0207] (8) The melt strength is measured by using the Rheotens melt strength meter manufactured by Germany Geottfert Werkstoff Pruefmaschinen Company. The polymer is melted and plasticized by a single screw extruder, then extruded down the melt strip through a 90° steering head with 30/2 aspect ratio die, the strip is held between a plurality of rollers which rotate at a constant acceleration for uniaxial extension, measuring and recording the force of the melt drawing process via the force measuring unit that connected to the drawing roller, the maximum force value which measured at the time of melt stretch to fracture is defined as melt strength.

[0208] (9) Molecular weight (M.sub.w, M.sub.n) and molecular weight distribution (M.sub.w/M.sub.n, M.sub.z+1/M.sub.w): PL-GPC 220 gel permeation chromatography manufactured by Polymer Laboratories, USA, or GPC-IR instrument (IR5 concentration detector) manufactured by Spain Polymer Char company is used to determine the molecular weight and molecular weight distribution of the samples. The chromatographic column is three PLgel 13 μm Olexis columns connected in series, solvent and mobile phase are 1,2,4-trichlorobenzene (containing 250 ppm of antioxidant 2,6-dibutyl p-cresol), column temperature 150° C., flow rate 1.0 ml/min, using EasiCal PS-1 narrowly distributed polystyrene standards from the PL company for universal calibration.

[0209] The process for preparing trichlorobenzene solubles at room temperature matter is as follows: accurately weighed the sample and trichlorobenzene solvent, dissolved at 150° C. for 5 hours, after standing at 25° C. for 15 hours, use of quantitative glass fiber filter paper to filter, to obtain trichlorobenzene solubles solution at room temperature which is used for the determination. The GPC curve area is corrected by using polypropylene at known concentration, to determine the content of trichlorobenzene solubles at room temperature, the molecular weight data of trichlorobenzenein solubles at room temperature are calculated from the GPC data of the original sample and the GPC data of the soluble matter.

[0210] (10) Density measurement: according to GB/T 1033.1-2008 (corresponding to ISO1183), the densities of the polypropylene base resin and the expanded polypropylene beads are obtained by the drainage method by using the density attachment of the Satorius balance. The expansion ratio of the obtained expanded polypropylene material is calculated by the formula: b=ρ.sub.1/ρ.sub.2, wherein b is the expansion ratio, pi is the density of the polypropylene base resin, and ρ.sub.2 is the apparent density of the expanded material.

[0211] (11) Oxygen index test: testing according to the method as described in GB T 2406.2-2009 (corresponding to ISO4589).

[0212] (12) Surface resistivity test: testing according to GB/T 1410-2006 [corresponding to the International Electro Technical Commission (IEC) IEC60167].

[0213] (13) Compressive strength test: A 50*50*25 mm sample is cut from the expanded beads molded body, tested on the universal material testing machine 5967 based on American ASTM standard D3575-08, compression rate of 10 mm/min, the compression strength is obtained when the molded body is compressed by 50%.

Preparation of Polypropylene Base Resin HMSPP

Preparation of Polypropylene Base Resin HMSPP601

[0214] Propylene polymerization is carried out on the polypropylene apparatus, and the main equipment of the apparatus comprises the prepolymerization reactor, the first loop reactor, the second loop reactor and the third gas phase reactor. The polymerization process and the steps are as follows.

(1) Prepolymerization Reaction

[0215] The main catalyst (DQC-401 catalyst, provided by Sinopec Catalyst Company Beijing Oda Branch), cocatalyst (triethylaluminum), the first external electron donor (dicyclopentyl-dimethoxysilane, DCPMS), after precontacted at 6° C. for 20 min, continuously added into a continuous stirred tank prepolymerization reactor for prepolymerization reaction. The flow rate of triethylaluminum (TEA) entered into the prepolymerisation reactor is 6.33 g/hr, the flow rate of the dicyclopentyl-dimethoxysilane is 0.3 g/hr, the flow rate of the main catalyst is 0.6 g/hr, the TEA/DCPMS ratio is 50 mol/mol. The prepolymerization is carried out under the propylene liquid phase bulk conditions, at the temperature of 15° C. and the residence time of about 4 min, the catalyst had a prepolymerization ratio of about 80-120 times under these conditions.

(2) The First Step: Propylene Homopolymerization

[0216] The first stage: after prepolymerization, the catalyst continuously entered into the first loop reactor to complete the first stage propylene homopolymerization. In the first loop reactor, polymerization temperature is 70° C., the reaction pressure is 4.0 MPa; the feeding of the first loop reactor does not contain hydrogen, the hydrogen concentration of the online chromatographic detection in feedstock is less than 10 ppm, the first propylene homopolymer A is obtained.

[0217] The second stage: the second stage propylene homopolymerization is carried out in the second loop reactor which connected with the first loop reactor in series. With the mixture of the 0.63 g/hr of tetraethoxysilane (TEOS) which added into the propylene in the second loop reactor and the reactant stream from the first loop reactor, the TEA/TEOS ratio is 5 (mol/mol), and the TEOS is the second external electron donor. In the second loop reactor, the polymerization temperature is 70° C., the reaction pressure is 4.0 MPa; the certain amount of hydrogen is added while the propylene is feed, the hydrogen concentration of the online chromatographic detection in feedstock is 3000 ppm. The second propylene homopolymer B is produced in the second loop reactor, to obtain the propylene homopolymer component comprising the first propylene homopolymer and the second propylene homopolymer.

(3) The Second Step: Ethylene Propylene Copolymerization

[0218] A certain amount of hydrogen is added to the third reactor, H.sub.2/(C.sub.2+C.sub.3)=0.06 (mol/mol), C.sub.2/(C.sub.2+C.sub.3)=0.3 (mol/mol) (C.sub.2 and C.sub.3 respectively refer to ethylene and propylene), the ethylene/propylene copolymerization is continued in the third reactor, at reaction temperature of 75° C., to produce the propylene-ethylene copolymer component C.

[0219] The final product contains the first propylene homopolymer, the second propylene homopolymer and the propylene-ethylene copolymer component, the polymer powder is obtained by removed the unreacted catalyst via wet nitrogen and dried by heating. 0.1% by weight of IRGAFOS 168 additive, 0.1% by weight of IRGANOX 1010 additive and 0.05% by weight of calcium stearate are added into the powder which is obtained from polymerization, pelletized with a twin-screw extruder. The analysis results and the physical properties of the obtained polymers are shown in tables 1 and 2.

Preparation of Polypropylene Base Resin HMSPP602

[0220] HMSPP602 used the same the catalyst, process conditions pre-complexation and polymerization as HMSPP601. The difference from HMSPP601 is that the amount of hydrogen in the second reactor in the second stage is changed to 13000 ppm, H.sub.2/(C.sub.2+C.sub.3) in the gas phase reactor during the second step is adjusted to 0.49 (mol/mol). The first external electron donor is replaced by methyl-isopropyl-dimethoxysilane (MIPMS), the amount is unchanged. The analysis results and the physical properties of the obtained polymers are shown in tables 1 and 2.

Preparation of Polypropylene Base Resin HMSPP602

[0221] HMSPP603 used the same the catalyst, process conditions of pre-complexation and polymerization as HMSPP601. The difference from HMSPP601 is that the second external electron donor is changed to 2,2-diisobutyl-1,3-dimethoxypropane (DIBMP), the amount is unchanged, the amount of hydrogen gas in the second reactor during the second stage is adjusted to 3600 ppm. The analysis results and the physical properties of the obtained polymers are shown in tables 1 and 2.

TABLE-US-00001 TABLE 1 The process conditions and analysis results of the basic resin polymerization¶ Hydrogen H.sub.2/C.sub.2 + C.sub.2/C.sub.2 + concentration C.sub.3) C.sub.3) (ppm)  (v/v) (v/v) The The first second The The MFR¶ stage stage second second (g/10 min) homo- homo- step step The type of the poly- poly- homo- homo- Poly- external electron mer- mer- poly- poly- mer¶ donor  iza- iza- mer- mer- (A + DONOR- DONOR- tion tion ization ization B) Brand   1 2         HMSPP601 DCPMS  TEOS  0  3000  0.06  0.3  0.4  HMSPP602 MIPMS  TEOS  0  3000  0.06  0.3  0.4  HMSPP603 DCPMS  DIBMP  0  3600  0.06  0.3  0.38  MFR¶ (g/10 min) Size and Size and distribution of distribution of Poly- molecular weight¶ molecular weight mer¶ (polymer A + B)  (polymer A + B + C)  (A + M.sub.w × M.sub.w × B + 10.sup.−4¶ M.sub.w/ M.sub.x+1/ 10.sup.−4¶ M.sub.w/ M.sub.x+1/ C) (g/mol) M.sub.n M.sub.or (g/mol) M.sub.n M.sub.or 0.43  96.8  10.5  106  71.8  7.9  12  0.43  97.2  10.4  107  70.6  7.0  12.7  0.4  98.0  10.8  110  73.2  8.1  12.3  Note: DONOR-1 is the first external electron donor, DONOR-2 is the second first external electron donor.¶

TABLE-US-00002 TABLE 2 The physical properties of the polypropylene base resin¶ M.sub.w(tri- M.sub.w of M.sub.n of chloro- tri- tri- benzene- chloro- chloro- solubles The Melt Melt ben- ben- room temp- The ethylene strength strength The zene- zene- erature/ content content Die Die ethylene solu- solu- M.sub.w(tri- of of head head content bles¶ bles chloro- xylene xylene Poly- Bend- temper- temper- Izod of at room at room benzene¶ solubles solubles disp- ing ature ature Notched the base temper- temper- Insolubles at room at room ersity modu- is is impact¶ resin ¶ ature ature at room temper- temper- (PI) Tensile lus 200° 220° 23° C.¶ (wt %) (10.sup.4 g/ (10.sup.4 g/ temper- ature ature ¶ strength GPa C.) C.) (KJ/m.sup.2) Brand     mol) mol) ature)  (wt %)  (wt %)    MPa    (N)  (N)      HMSPP601  10.0  56.7  81.3  0.70  19.8  42.9  5.27  24.4  0.93  >2  1.3  82.6    HMSPP602  10.5  55.2  80.6  0.68  21.8  46.7  5.2  23.5  0.91  >2  1.3  88.4    HMSPP603   9.2  54.3  82.1  0.66  17.5  42.5  5.1  25.8  1.01  >2  1.4  77.6   

Example 1

[0222] The raw material ratio and the reaction conditions of the flame retardant, the polypropylene composition and the foam beads etc. which are prepared in this example are shown in Tables 3 and 4, Table 4 also lists the performance parameters of the foam beads. In the tables, the flame retardant component A is phosphine oxide, the flame retardant component B is transition metal salt, and the flame retardant component C is inorganic flame retardant component.

(a) Preparation of Flame Retardant (Halogen-Free)

[0223] The triphenylphosphine oxide and cobalt nitrate are added to ethanol, stirred at a rate of 100 rpm, the mixture is then heated under stirring by using microwave irradiation with a heating power of 50 W, a temperature of 40° C. and a heating time of 4 h. The complex Co(OPPh.sub.3).sub.2(NO.sub.3).sub.2 is obtained by supercritical dried the material after microwave heating reaction, wherein the complex formed by the reaction of triphenylphosphine oxide with cobalt nitrate.

[0224] The infrared spectrum of the abovementioned complex is shown in FIG. 1. It can be seen from FIG. 1 that the peaks at 1143 and 1070 cm.sup.−1 correspond to the P—O stretching vibration, and move toward the low wave number, indicating the formation of the complex. The peaks at 1258, 1024, 812 cm.sup.−1 correspond to the O.NO.sub.2 complexing, thus demonstrating the tetrahedral structure of the complex.

[0225] The microstructure of the complex is shown in FIG. 2.

(b) Preparation of Composite Flame Retardant (Halogen-Free)

[0226] The above mentioned prepared complex Co(OPPh.sub.3).sub.2(NO.sub.3).sub.2 is mechanically stirred with magnesium hydroxide, stirred at a rate of 10 rpm to obtain the composite flame retardant.

(c) Preparation of Carbon Nanofiber Antistatic Agent

[0227] The pretreated material is obtained by using coal tar pitch with carbon content of 85 wt % as carbon source, performed the grinding pretreatment with phosphoric acid/nitric acid/hydrochloric acid (volume ratio 1:1:1).

[0228] The above mentioned pretreated material and the catalyst cobalt nitrate are added into the ball mill to mix to obtain the complex.

[0229] The above mentioned complex is subjected to the carbonization reaction under a high purity nitrogen protection at 950° C., constant temperature for 1.5 hours, then cooled to room temperature to obtain self-assembled carbon nanofibers. No need for post treatment to remove catalyst metal impurities, cobalt 2 wt % by measured.

[0230] The microstructure of the carbon nanofibers is shown in FIG. 3.

(d) Preparation of Flame Retardant Antistatic Polypropylene Composition (Halogen-Free)

[0231] The HMSPP601, the abovementioned prepared carbon nanofiber antistatic agent, zinc borate as a cell nucleating agent, the antioxidant 1010 (BASF), and the antioxidant 168 (BASF) are added together with the above-prepared composite flame retardant into the high speed stirrer mixed evenly. The mixed material is then fed into the feeder of the twin-screw extruder which manufactured by Coperion, the material enters the twin screw via the feeder, the temperature of the screw is maintained between 170 and 200° C. during processing. Melt and mixed evenly via the screw, enter the Labline100 micro-particle preparation system, torque control in about 65%, speed 300 rpm. The flame retardant antistatic polypropylene composition micropellets are obtained. The Izod notched impact of the composition material at 23° C. is 25.8 KJ/m.sup.2.

(e) Preparation of Flame Retardant Antistatic Expanded Polypropylene Beads (Halogen-Free)

[0232] (1) The above mentioned prepared flame retardant antistatic polypropylene composition and the dispersing medium water, the surfactant sodium dodecylbenzene sulfonate, dispersant kaolin, and dispersant reinforcing agent aluminum sulfate are added and mixed at onetime range to obtain the dispersion.

[0233] (2) The residual air in the autoclave is vented by using inert blowing agent carbon dioxide, continue to pass the inert blowing agent, the initial adjusts the pressure inside the autoclave until it is stable. Then the dispersion in the autoclave is stirred.

[0234] (3) Subsequently, adjust the pressure inside the autoclave to achieve the pressure required for foaming. The temperature is raised to the foaming temperature at an average heating rate of 0.1° C./min, and the foaming temperature is 0.5 to 1° C. lower than the melting temperature of the micropellets. Under the foaming temperature and pressure conditions, stirring is continued for 0.25 to 0.5 hours.

[0235] (4) The outlet of the autoclave is then opened, the contents of the autoclave are discharged into the collection tank to obtain polypropylene foam beads. The carbon dioxide gas is fed while the discharge is being carried out, so that the pressure in the autoclave is maintained around the foaming pressure before all the particles are completely foam and enter the collection tank. Followed by washing and drying foam beads, the temperature is 80° C., drying time is 5 h.

[0236] (5) The density of the foam beads is measured. The results are shown in Table 4. The surface and cross sectional morphology of the foam beads are characterized by scanning electron microscopy, see FIGS. 4 and 5.

(f) Preparation and Performance Test of Foam Beads

[0237] The dried foam beads are subjected to stand at room temperature for about 12 hours, then added into the molding machine, molded to foam beads to form a molded body of the foam beads by using the water vapor under molding pressure of 0.22 MPa. The obtained product is allowed to stand in an oven at 80° C. for 12 hours. The oxygen index, the carbon residue content, the flame height, the smoke condition, the surface resistivity, and the compressive strength of the molded body are measured according to the method described above. Wherein the surface resistivity of the molded body is measured when the preparing the molded body is completed, and the surface resistivity thereof is measured again after standing for 30 days in the absence of special protective measures. The results of the tests are shown in Table 4.

Example 2

[0238] The processes for preparing flame retardant, the composite flame retardant, the carbon nanofiber antistatic agent, the flame retardant antistatic polypropylene composition and the foam beads are similar to that of Example 1, except the raw material formulation and reaction conditions shown in Tables 3 and 4. For example, this example adopts HMSPP602, the formed halogen-free flame retardant is the complex Ni(OPot.sub.3).sub.2(NO.sub.3).sub.2 which formed by the trioctyl phosphine oxide and nickel nitrate, the prepared carbon nanofiber antistatic agent containing nickel 3 wt %.

Example 3

[0239] The processes for preparing flame retardant, the composite flame retardant, the carbon nanofiber antistatic agent, the flame retardant antistatic polypropylene composition and the foam beads are similar to that of Example 1, except the raw material formulation and reaction conditions shown in Tables 3 and 4. For example, this example adopts HMSPP603, the formed halogen-free flame retardant is the complex Ni (OPOt.sub.3).sub.2(NO.sub.3).sub.2 which formed by the trioctyl phosphine oxide and cobalt nitrate.

Example 4

[0240] The processes for preparing flame retardant, the composite flame retardant, the carbon nanofiber antistatic agent, the flame retardant antistatic polypropylene composition and the foam beads are similar to that of Example 1, except the raw material formulation and reaction conditions shown in Tables 3 and 4. For example, the formed halogen-free flame retardant is the complex Ni (OPPh.sub.3).sub.2(NO.sub.3).sub.2 which formed by the triphenylphosphine oxide and nickel nitrate.

Example 5

[0241] The processes for preparing flame retardant, the composite flame retardant, the carbon nanofiber antistatic agent, the flame retardant antistatic polypropylene composition and the foam beads are similar to that of Example 1, except the raw material formulation and reaction conditions shown in Tables 3 and 4. For example, this example adopts HMSPP602, the formed halogen-free flame retardant is the complex Ni (OPHx.sub.3).sub.2(NO.sub.3).sub.2 which formed by the trihexylphosphine oxide and nickel nitrate.

Example 6

[0242] The processes for preparing flame retardant, the complex flame retardant, the carbon nanofiber antistatic agent, the flame retardant antistatic polypropylene composition and the foam beads are similar to that of Example 1, except the raw material formulation and reaction conditions shown in Tables 3 and 4. For example, this example adopts HMSPP603, the formed halogen-free flame retardant is the complex Ni (OPDe.sub.3).sub.2(NO.sub.3).sub.2 which formed by the tridecylphosphine oxide and nickel nitrate.

Example 7

[0243] The test procedure is carried out similar to that of Example 1, except that the carbon nanofiber antistatic agent is not prepared and used in this example. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 8

[0244] The test procedure is carried out similar to that of Example 1, except that tributyl phosphate is used instead of triphenylphosphine oxide to prepare the complex. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 9

[0245] The test procedure is carried out similar to that of Example 1, except that dibutyl butylphosphate is used instead of triphenylphosphine oxide to prepare the complex, and without using the inorganic flame retardant component. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 10

[0246] The test procedure is carried out similar to that of Example 1, except that the ordinary impact copolymer polypropylene EPS30R is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 11

[0247] The test procedure is carried out similar to that of Example 1, except that the process (c) is not carried out, and the antistatic agent is replaced by carbon black in the preparing the flame retardant antistatic polypropylene composition in the process (d). The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 12

[0248] The test procedure is carried out similar to that of Example 1, except that the process (c) is not carried out, and the antistatic agent is replaced by Atmer 129 in the preparing the flame retardant antistatic polypropylene composition in the process (d). The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 13

[0249] The test procedure is carried out similar to that of Example 1, except that straight chain low density polyethylene 7042 with butene-1 iscomonomer is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 14

[0250] The test procedure is carried out similar to that of Example 1, except that the metallocene catalyst and the polyethylene HPE1 with hexene-1 is the comonomer are used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 15

[0251] The test procedure is carried out similar to that of Example 1, except that the Zygler Natta catalyst and the polyethylene HPE2 with hexene-1 is comonomer are used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 16

[0252] The test procedure is carried out similar to that of Example 1, except that low density polyethylene LD100ac is used place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 17

[0253] The test procedure is carried out similar to that of Example 1, except that the foaming-grade polylactic acid is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 18

[0254] The test procedure is carried out similar to that of Example 1, except that the foam grade TPU is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 19

[0255] The test procedure is carried out similar to that of Example 1, except that the foam grade PBT is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 20

[0256] The test procedure is carried out similar to that of Example 1, except that the foam PET is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 21

[0257] The test procedure is carried out similar to that of Example 1, except that the foam grade nylon 6 is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Example 22

[0258] The test procedure is carried out similar to that of Example 1, except that the polybutylene succinate base resin is used in place of the high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 1

[0259] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not carried out, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by red phosphorus. The results of the specific raw materials formula, the reaction conditions and the final performance of the foam material are shown in Table 3 and Table 4. The surface electron microscopy of the prepared polypropylene foam beads is shown in FIG. 6, and the prepared polypropylene foam beads are shown in FIG. 7.

Comparative Example 2

[0260] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are carried out, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the test is carried out with the composite flame retardant is replaced by the composition of hexabromocyclododecane and antimony trioxide (weight ratio about 2.5:1). The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 3

[0261] The test procedure is carried out similar to that of Example 2, except that the process (a) and (b) are not carried out, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by only using aluminum hydroxide. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 4

[0262] The test procedure is carried out similar to that of Example 3, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by ammonium polyphosphate. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 5

[0263] The test procedure is carried out similar to that of Example 1, except that the flame retardant is replaced by only using triphenylphosphine oxide. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 6

[0264] The test procedure is carried out similar to that of Example 1, except that the flame retardant is replaced by only using cobalt phosphate. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 7

[0265] The test procedure is carried out similar to that of Example 1, except that the flame retardant is replaced by trimethylol phosphine oxide. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 8

[0266] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Straight chain low density polyethylene 7042 with butene-1 as comonomer is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 9

[0267] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. The metallocene catalyst, hexene-1 is comonomer for polyethylene HPE1 are used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 10

[0268] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. The Ziegler Natta catalyst, hexene-1 is comonomer for polyethylene HPE2 are used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 11

[0269] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Low density polyethylene LD100ac is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 12

[0270] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Foam grade polylactic acid instead is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 13

[0271] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Foam TPU is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 14

[0272] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Foam grade PBT is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 15

[0273] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Foam grade PET is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 16

[0274] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. Foam grade nylon 6 is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

Comparative Example 17

[0275] The test procedure is carried out similar to that of Example 1, except that the process (a) and (b) are not followed, and in the preparing the flame retardant antistatic polypropylene composition of the process (d), the composite flame retardant is replaced by the red phosphorus to test. The polybutylene succinate base resin is used in place of high melt strength polypropylene base resin HMSPP601. The results of the specific raw materials formulation, reaction conditions and the final properties of the foam material are shown in Table 3 and Table 4.

TABLE-US-00003 TABLE 3 The formulations of the polypropylene compositions used in Examples and Comparative Examples Flame retardant Flame retardant Flame retardant Component A component B component C Amount Parts Parts Parts Base by Flame by by by Project resin weight retardant Type weight Type weight Type weight Example 1 HMSPP601 100 — Triphenyl- 7 Cobalt 3 Magnesium 3 phosphine nitrate hydroxide oxide Example 2 HMSPP602 100 — Trioctyl- 6 Nickel 4 Aluminum 4 phosphine nitrate hydroxide oxide Example 3 HMSPP603 100 — Trioctyl- 6.5 Cobalt 4.5 Aluminum 4.5 phosphine nitrate hydroxide oxide Example 4 HMSPP601 100 — Triphenyl- 8.4 Nickel 3.6 Magnesium 3 phosphine nitrate hydroxide oxide Example 5 HMSPP602 100 — Trihexyl- 7.5 Nickel 3.5 Aluminum 3.5 phosphine nitrate hydroxide oxide Example 6 HMSPP603 100 Tridecyl- 6.5 Cobalt 2.5 Magnesium 4 phosphine nitrate hydroxide oxide Example 7 HMSPP601 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 8 HMSPP601 100 — Tributyl- 8 Nickel 2.5 Magnesium 4 phosphate nitrate hydroxide Example 9 HMSPP601 100 — Butyl 7 Nickel 3 — — dibutyl- nitrate phosphate Example 10 EPS30R 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 11 HMSPP601 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 12 HMSPP601 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 13 LLDPE7042 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 14 HPE001 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 15 HPE002 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 16 LD100AC 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 17 PLA 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 18 TPU 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 19 PBT 100 — Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 20 PET 100 Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 21 PA6 100 Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Example 22 PBS 100 Triphenyl- 7 Cobalt 3 Magnesium 5 phosphine nitrate hydroxide oxide Comparative HMSPP601 100 Red — 20 — — — — Example 1 phosphorus Comparative HMSPP601 100 Composition — — — — — — Example 2 of hexabromo- cyclo- dodecane antimony trioxide Comparative HMSPP602 100 — — — — — Aluminum 12 Example 3 hydroxide Comparative HMSPP603 100 Ammonium — 35 — — — — Example 4 polyphosphate Comparative HMSPP601 100 — Triphenyl- 7 — — Magnesium 5 Example 5 phosphine hydroxide oxide Comparative HMSPP601 100 Cobalt — 25 — — — — Example 6 phosphate Comparative HMSPP601 100 Trimethylol — 25 — — — — Example 7 phosphine oxide Comparative LLDPE7042 100 Red — 20 — — — — Example 8 phosphorus Comparative HPE001 100 Red — 20 — — — — Example 9 phosphorus Comparative HPE002 100 Red — 20 — — — — Example 10 phosphorus Comparative PBS 100 Red — 20 — — — — Example 11 phosphorus Comparative LD100AC 100 Red — 20 — — — — Example 12 phosphorus Comparative TPU 100 Red — 20 — — — — Example 13 phosphorus Comparative PBT 100 Red — 20 — — — — Example 14 phosphorus Comparative PET 100 Red — 20 — — — — Example 15 phosphorus Comparative Nylon 6 100 Red — 20 — — — — Example 16 phosphorus Comparative PBS 100 Red — 20 — — — — Example 17 phosphorus Preparation and amount of antistatic agent Cell nucleating agent Carbonization Holding Parts Parts Carbon Catalyst temperature/ time/ by by Project source type ° C. hour Type weight Type weight Example 1 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 2 Coal tar Nickel 1050 2.5 Carbon 1.5 Zinc 0.4 pitch nitrate nanofiber borate Example 3 Asphalt Nickel 1000 2 Carbon 1.5 Zinc 0.5 nitrate nanofiber borate Example 4 Coal tar Nickel 1050 2.5 Carbon 1 Zinc 0.4 pitch nitrate nanofiber borate Example 5 Bamboo Nickel 1150 1.5 Carbon 1.5 Zinc 0.5 charcoal nitrate nanofiber borate Example 6 Bamboo Cobalt 1000 2 Carbon 1 Zinc 0.3 charcoal nitrate nanofiber borate Example 7 Coal tar Cobalt 950 1.5 — — Zinc 0.5 pitch nitrate borate Example 8 Bamboo Nickel 1150 1.5 Carbon 1.5 Zinc 0.3 charcoal nitrate nanofiber borate Example 9 Asphalt Nickel 1000 2 Carbon 1.5 Calcium 0.3 nitrate nanofiber carbonate Example 10 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 11 — — — — carbon 6 Zinc 0.5 black borate Example 12 — — — — Atmer129 3 Zinc 0.5 borate Example 13 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nonofiber borate Example 14 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 15 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 16 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 17 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 18 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 19 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 20 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 21 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Example 22 Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 1 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 2 pitch nitrate nanofiber borate Comparative Coal tar Nickel 1050 2.5 Carbon 1.5 Zinc 0.5 Example 3 pitch nitrate nanofiber borate Comparative Asphalt Nickel 1000 2 Carbon 1.5 Zinc 0.5 Example 4 nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 5 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 6 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 7 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 8 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 9 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 10 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 11 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 12 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 13 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 14 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 15 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 16 pitch nitrate nanofiber borate Comparative Coal tar Cobalt 950 1.5 Carbon 1 Zinc 0.5 Example 17 pitch nitrate nanofiber borate

TABLE-US-00004 TABLE 4 The comparison of process parameters and product performance of flame-retardant thermoplastic foam beads which are prepared in Examples and Comparative Examples Expand 50% Residual Foaming Foaming Sample Cell beads fusion Compressive Burn mass Flame Limit temperature pressure density density/ pressure strength off fraction height oxygen Project ° C. MPa g/cm.sup.3 cm.sup.3 MPa kPa time s % mm indexLOT Example 1 160 2 0.21 2.5 × 10.sup.8 0.22 579 2 3.2 15 29.5 Example 2 162 2.5 0.18 3.4 × 10.sup.8 0.23 578 2 3.5 14 29.6 Example 3 161 3 0.15 3.7 × 10.sup.8 0.21 576 2 3.3 13 28.6 Example 4 159 3.5 0.11 3.9 × 10.sup.8 0.22 575 2 3.4 13 30.1 Example 5 160 4 0.09 5.5 × 10.sup.8 0.23 573 1 3.3 15 30.2 Example 6 162 4.5 0.07 5.1 × 10.sup.8 0.22 571 2 3.6 14 28.9 Example 7 161 4 0.10 4.9 × 10.sup.8 0.22 572 1 3.3 13 29.2 Example 8 160 4 0.09 4.8 × 10.sup.8 0.23 573 1 3.4 12 30.2 Example 9 161 4 0.11 5.0 × 10.sup.8 0.23 574 1 3.5 14 29.9 Example 10 165 3 0.15 8.5 × 10.sup.8 0.29 575 4 3.2 19 25.1 Example 11 159 2.5 0.13 9.2 × 10.sup.8 0.36 178 3 4.3 20 21.2 Example 12 165 3 0.15 8.5 × 10.sup.8 0.29 177 4 3.2 19 25.1 Example 13 124 3.5 0.12 4.1 × 10.sup.8 0.15 395 2 3.2 13 29.6 Example 14 126 4 0.11 2.5 × 10.sup.8 0.18 405 2 3.1 14 29.5 Example 15 126 3.5 0.1 3.2 × 10.sup.8 0.17 408 2 3.5 13 30.1 Example 16 110 3.5 0.11 1.8 × 10.sup.8 0.18 239 2 3.1 15 29.2 Example 17 145 3 0.08 1.5 × 10.sup.8 0.16 368 2 3.2 15 28.5 Example 18 80 5 0.19 1.6 × 10.sup.8 0.35 313 2 3.2 14 28.3 Example 19 180 5 0.18 2.1 × 10.sup.8 0.45 408 1 3.1 13 28.4 Example 20 200 3.5 0.15 2.5 × 10.sup.8 0.32 509 1 3.5 13 28.2 Example 21 220 3.5 0.19 3.4 × 10.sup.8 0.64 575 1 3.3 14 28.5 Example 22 120 4 0.22 2.5 × 10.sup.6 0.19 495 1 3.1 12 29.8 Comparative 162 2.5 0.16 3.5 × 10.sup.4 0.28 180 5 5.5 27 17.0 Example 1 Comparative 161 2 0.13 8.4 × 10.sup.5 0.35 181 3 4.9 21 22.9 Example 2 Comparative 162 2.5 0.17 3.8 × 10.sup.5 0.35 179 5 4.7 21 20.1 Example 3 Comparative 161 3 0.14 4.9 × 10.sup.5 0.37 176 4 3.8 16 22.3 Example 4 Comparative 160 2 0.23 9.4 × 10.sup.5 0.22 395 4 5.5 21 22.1 Example 5 Comparative 162 2.5 0.21 8.5 × 10.sup.5 0.23 421 5 4.2 20 24.4 Example 6 Comparative 161 3 0.18 8.6 × 10.sup.5 0.21 412 4 3.3 22 23.7 Example 7 Comparative 124 3.5 0.15 2.3 × 10.sup.6 0.15 318 5 5.2 21 20.5 Example 8 Comparative 126 4 0.19 4.2 × 10.sup.6 0.18 352 6 6.1 19 21.6 Example 9 Comparative 126 3.5 0.18 9.1 × 10.sup.6 0.17 235 5 5.5 21 24.5 Example 10 Comparative 110 3.5 0.19 2.4 × 10.sup.6 0.18 205 6 6.1 18 25.1 Example 11 Comparative 145 3 0.21 3.5 × 10.sup.6 0.16 345 6 7.2 19 23.5 Example 12 Comparative 80 5 0.45 4.5 × 10.sup.6 0.35 399 4 5.2 25 23.4 Example 13 Comparative 180 5 0.46 5.8 × 10.sup.6 0.45 358 5 4.1 21 25.2 Example 14 Comparative 200 3.5 0.25 1.5 × 10.sup.6 0.44 398 6 6.1 27 24.3 Example 15 Comparative 220 3.5 0.34 2.4 × 10.sup.6 0.55 415 5 5.5 26 21.6 Example 16 Comparative 120 4 0.41 1.6 × 10.sup.6 0.53 296 4 6 25.5 20.1 Example 17 Surface Surface Surface Smog and cell resistivityΩ resistivityΩ Project situation structure (Day 0) (Day 30) Example 1 — √ 6.0*10.sup.6 6.1*10.sup.8 Example 2 — √ 3.4*10.sup.8 3.5*10.sup.8 Example 3 — √ 4.2*10.sup.8 4.3*10.sup.8 Example 4 — √ 1.1*10.sup.8 1.2*10.sup.8 Example 5 — √ 4.4*10.sup.6 4.6*10.sup.8 Example 6 — √ 9.3*10.sup.8 9.4*10.sup.6 Example 7 — √ .sup. 1.2*10.sup.13 .sup. 1.3*10.sup.12 Example 8 — √ 5.4*10.sup.8 5.6*10.sup.6 Example 9 — √ 4.3*10.sup.6 4.4*10.sup.8 Example 10 — x 2.6*10.sup.8 2.7*10.sup.8 Example 11 ∘ x 1.3*10.sup.6 1.4*10.sup.8 Example 12 — x 3.5*10.sup.8 .sup. 2.8*10.sup.13 Example 13 — √ 3.4*10.sup.6 3.5*10.sup.8 Example 14 — √ 4.0*10.sup.8 4.1*10.sup.6 Example 15 — √ 3.3*10.sup.6 3.4*10.sup.8 Example 16 — √ 2.5*10.sup.8 2.6*10.sup.6 Example 17 — √ 4.4*10.sup.8 4.5*10.sup.8 Example 18 — √ 5.6*10.sup.8 5.7*10.sup.6 Example 19 — √ 4.7*10.sup.6 4.8*10.sup.8 Example 20 — √ 2.1*10.sup.8 2.2*10.sup.6 Example 21 — √ 3.5*10.sup.6 3.6*10.sup.8 Example 22 — √ 4.2*10.sup.6 4.3*10.sup.8 Comparative ∘ x .sup. 3.4*10.sup.11 .sup. 3.5*10.sup.11 Example 1 Comparative ∘ x .sup. 5.2*10.sup.10 .sup. 5.3*10.sup.16 Example 2 Comparative ∘ x .sup. 9.3*10.sup.10 .sup. 9.4*10.sup.11 Example 3 Comparative — x .sup. 1.5*10.sup.11 .sup. 1.5*10.sup.11 Example 4 Comparative ∘ x .sup. 5.3*10.sup.11 .sup. 5.4*10.sup.11 Example 5 Comparative ∘ x .sup. 2.4*10.sup.11 .sup. 2.5*10.sup.11 Example 6 Comparative ∘ x .sup. 6.5*10.sup.11 .sup. 6.6*10.sup.11 Example 7 Comparative ∘ x .sup. 4.3*10.sup.11 .sup. 4.4*10.sup.11 Example 8 Comparative ∘ x .sup. 2.5*10.sup.11 .sup. 2.6*10.sup.11 Example 9 Comparative ∘ x .sup. 6.5*10.sup.11 .sup. 6.5*10.sup.11 Example 10 Comparative ∘ x .sup. 7.4*10.sup.11 .sup. 7.5*10.sup.11 Example 11 Comparative ∘ x .sup. 6.5*10.sup.11 .sup. 6.6*10.sup.11 Example 12 Comparative ∘ x .sup. 4.2*10.sup.11 .sup. 4.3*10.sup.11 Example 13 Comparative ∘ x .sup. 5.7*10.sup.11 .sup. 5.8*10.sup.11 Example 14 Comparative — √ .sup. 6.3*10.sup.11 .sup. 6.4*10.sup.11 Example 15 Comparative — √ .sup. 8.2*10.sup.11 .sup. 8.3*10.sup.11 Example 16 Comparative — √ .sup. 2.3*10.sup.11 .sup. 2.4*10.sup.11 Example 17

[0276] As can be seen from Table 1 and Table 2, the prepared HMSPP601, HMSPP602 and HMSPP603 polypropylenes according to the present invention have high melt strength, tensile strength and flexural modulus, and high notched impact strength.

[0277] The prepared high melt strength impact polypropylene according to the present invention as the base resin, add the flame retardant which composited by the complex formed by phosphine oxide and transition metal salt, with inorganic hydroxide, and carbon nanofibers or carbon nanotubes containing nickel or cobalt, as the antistatic agent, to prepare the flame-retardant antistatic composition, followed by preparing the flame-retardant antistatic foam beads according to the kettle impregnating and foaming process provided by the present invention. From Table 3, Table 4 and FIGS. 4 and 5, it can be seen that foaming beads having the density of 0.07 to 0.21 g/cm.sup.3 can be obtained by adjusting the conditions such as foaming pressure and temperature, and when non-supercritical carbon dioxide is used as the blowing agent, foaming effect is good, the cell density is higher, the cell density is uniform, the cell size is smaller, the cell wall is thin, the bead surface is smooth.

[0278] As the result of Example 10, it can be seen that the foam beads obtained from the basic resin of the general impact copolymer polypropylene EPS30R has larger density, uneven cell, non-flat bead surface, compared to the impact polypropylene HMSPP601, HMSPP602 and HMSPP603 with high melt strength. This is mainly due to the lower melt strength of EPS30R, and the required higher foaming temperature, resulting in higher molding pressure. The above structural features will result in the impact resistance of the bead molded articles thereof inferior to the bead molded articles obtained by using the impact polypropylene with high melt strength (e.g., HMSPP601, 602 and 603) provided according to the present invention. In addition, the molding pressure of the foam beads obtained by using the conventional impact copolymer polypropylene is high, thereby improving the production energy consumption.

[0279] Table 4 shows that the molded body formed by the foam beads provided according to the present invention has excellent mechanical properties, flame retardancy and antistatic properties, wherein the oxygen index is higher than 28, can be used to the field requiring a higher flame resistant level, while the surface resistivity can reach 10.sup.8Ω antistatic level. The foam beads have a good cell structure that makes the molded article excellent in compressive properties. The results such as the oxygen index of the molded body and related flame resistance test results show that the flame retardant complex and the antistatic agent can play a synergistic effect, which can effectively reduce the amount of flame retardants, especially as evidenced by the results of Examples 1 and 7.

[0280] As a result of Table 4, particularly the results of Example 11, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, it can be seen that use the combination of conventional red phosphorus, brominated flame retardants, aluminum hydroxide and other flame retardants with carbon nanofibers containing nickel or cobalt, etc., as the composite flame retardant antistatic agent for the preparing polypropylene composition, the flame retardant and antistatic property of molded body formed based on foam beads prepared by such polypropylene composition are inferior to the foam beads obtained by the compositions described in Examples 1 to 8, and the addition of the flame retardant and the antistatic agent in the comparative example has a negative effect on the foaming property, resulting in cell is not uniform, the cell wall is damaged.

[0281] In an embodiment according to the present invention, in the flame retardant antistatic system which are composed of the composite flame retardant consisted of the complex formed by organophosphates and transition metal such as nickel or cobalt, magnesium hydroxide or aluminum hydroxide, and carbon nanofibers, the synergistic catalytic effect are carried out between the transition metal and magnesium hydroxide, improve the flame resistant efficiency of the phosphorus flame retardant. The carbon nanofibers can build an effective conductive network inside the resin, thereby form a long-acting antistatic network system, effectively reducing the surface resistivity of the foam bead molded body, its antistatic ability is almost unchanged within 30 days or more of the preservation or use of time. The residual nickel or cobalt catalyst in the carbon fiber also has a good synergistic effect with the complex to promote the improvement of flame resistant efficiency. In Comparative Example 1, using the composition obtained from the system formed by a conventional red phosphorus flame retardant and an antistatic agent, both of them do not have any synergistic effect, but instead influenced each other to reduce the flame retardancy and antistatic properties, and has a adverse effect on the cell structure of the beads, the obtained foam beads have low cell density, larger cell diameter, and the phenomenon of cell wall breakage is appear (as shown in FIGS. 6 and 7).

[0282] In addition, it can be found from Tables 3 and 4 that, in addition to be used in the polypropylene resin, the composite flame retardant and the antistatic agent are applied to polyethylene, polyester, nylon, and degradable thermoplastic materials of various densities and comonomers, still present some better performances in the mechanical properties, flame retardant properties, foam performance, and antistatic properties.

[0283] Any value mentioned in the present invention, includes all the values of one unit at a time from the lowest value to the highest value if there is only two units of the interval between any minimum value and any highest value. For example, if the amount of a component is stated, or if the value of the process variable such as temperature, pressure, time is 50-90, it means in the specification that 51-89, 52-88 . . . and 69-71 and 70-71 and other values. For non-integer values, it may be appropriate to consider 0.1, 0.01, 0.001 or 0.0001 as a unit. This is only a few specific examples. In this application, all possible combinations of numerical values between the lowest and highest values enumerated in a similar manner are considered to have been disclosed.

[0284] While the invention has been described in detail, it will be apparent that modifications within the spirit and scope of the invention will be apparent to those skilled in the art. In addition, it should be understood that various aspects of the invention, various parts of the various embodiments, and various features recited may be combined or fully or partially interchangeable. In each of the above specific embodiments, those embodiments which refer to another embodiment may be suitably combined with other embodiments, as will be understood by those skilled in the art. Furthermore, it will be understood by those skilled in the art that the foregoing description is only an example of the way and is not intended to limit the invention.