Flame-retardant Antimicrobial Agent, Preparation Method therefor and Use thereof, and Flame-retardant Antimicrobial Thermoplastic Resin Composition

Abstract

A flame-retardant antimicrobial agent is a polymer microsphere with the surface grafted thereof with a guanidine salt. The polymer microsphere has a cross-linked structure composed of a structural unit A derived from maleic anhydride, a structural unit B derived from a monomer M, and a structural unit C derived from a cross-linking agent. The monomer M is selected from a C.sub.4-C.sub.9 aliphatic olefin or a mixture thereof, and the guanidine salt comprises at least one guanidine salt having the property of flame resistance. The flame-retardant antimicrobial agent has both a good antimicrobial effect and a good flame-retardant effect. A flame-retardant antimicrobial thermoplastic resin composition containing the flame-retardant antimicrobial agent also has a good flame-retardant and antimicrobial performance and a good overall performance.

Claims

1. A flame-retardant antibacterial agent, which is a polymer microsphere grafted on its surface with a guanidine salt, wherein the polymer microsphere comprises a crosslinked structure constituted by a structural unit A derived from maleic anhydride, a structural unit B derived from a monomer M, and a structural unit C derived from a crosslinking agent, wherein the monomer M is selected from the group consisting of C.sub.4-C.sub.9 aliphatic olefins and mixtures thereof; and the guanidine salt comprises at least one flame-retardant guanidine salt.

2. The flame-retardant antibacterial agent according to claim 1, characterized in that the guanidine salt-grafted polymer microsphere has an average particle diameter in the range of 200-2000 nm; preferably, the polymer microsphere is monodispersed polymer microsphere.

3. The flame-retardant antibacterial agent according to claim 1, characterized in that the polymer microsphere as the graft base comprises a crosslinked alternating copolymer structure formed from maleic anhydride, a monomer M and a crosslinking agent.

4. The flame-retardant antibacterial agent according to claim 1, characterized in that the guanidine salt-grafted polymer microsphere has a shell crosslinked structure, and/or the crosslinking degree of the guanidine salt-grafted polymer microsphere is ≥50%, preferably ≥92%, as determined by a solvent extraction method.

5. The flame-retardant antibacterial agent according to claim 1, characterized in that the molar ratio of the structural unit A to the structural unit B ranges from (0.5:1) to (1:0.5), preferably from (0.75:1) to (1:0.75).

6. The flame-retardant antibacterial agent according to claim 1, characterized in that the monomer M is C.sub.4 and/or C.sub.5-aliphatic monoolefin or diolefin or a mixture of isomers thereof or a mixture of monoolefins and diolefins, preferably C.sub.4 and/or C.sub.5 fractions, more preferably the C.sub.4 and/or C.sub.5 fraction obtained from ethylene cracking process.

7. The flame-retardant antibacterial agent according to claim 1, characterized in that the crosslinking agent is selected from di-functional or higher-functional vinyl-containing monomers capable of free radical polymerization; preferably, the crosslinking agent is at least one selected from the group consisting of divinylbenzene and acrylate-based crosslinking agents containing at least two acrylate-based groups; the acrylate-based group preferably has the structural formula: —O—C(O)—C(R′)═CH.sub.2, wherein R′ is H or a C.sub.1-C.sub.4 alkyl group; more preferably, the crosslinking agent is one or more selected from the group consisting of divinylbenzene, propylene glycol-based bis(meth)acrylate, ethylene glycol-based bis(meth)acrylate, trimethylolpropane tri(meth)acrylate, bi s(trimethylolpropane) tetra(meth)acrylate, polyethylene glycol bis(meth)acrylate, phthalate ethylene glycol diacrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and ethoxylated multifunctional acrylate.

8. The flame-retardant antibacterial agent according to claim 1, characterized in that the guanidine salt is one or more selected from the group consisting of small molecule guanidine salts and guanidine salt polymers, preferably, the guanidine salt comprises at least one small molecule guanidine salt and at least one guanidine salt polymer; more preferably, both the small molecule guanidine salt and the guanidine salt polymer are flame-retardant guanidine salts; wherein, preferably, the small molecule guanidine salt is at least one selected from of the group consisting of: guanidine phosphate, guanidine hydrochloride, guanidine nitrate, guanidine hydrobromide, guanidine oxalate, guanidine dihydrogen phosphate, diguanidine hydrogen phosphate, and aminoguanidine salts such as inorganic acid salts and organic acid salts of monoaminoguanidine, diaminoguanidine and triaminoguanidine, such as carbonate, nitrate, phosphate, oxalate, hydrochloride, hydrobromide and sulfonate salts; more preferably, one or more selected from the group consisting of guanidine phosphate, guanidine hydrochloride, guanidine dihydrogen phosphate, diguanidine hydrogen phosphate, and the nitrate, phosphate, hydrochloride, hydrobromide and sulfonate salts of monoaminoguanidine, diaminoguanidine and triaminoguanidine; the guanidine salt polymer is preferably at least one selected from the group consisting of: inorganic acid salts and organic acid salts of polyhexamethylene (bi)guanidine, such as polyhexamethylene (bi)guanidine hydrochloride, polyhexamethylene (bi)guanidine phosphate, polyhexamethylene (bi)guanidine acetate, polyhexamethylene (bi)guanidine oxalate, polyhexamethylene (bi)guanidine stearate, polyhexamethylene (bi)guanidine laurate, polyhexamethylene (bi)guanidine benzoate, polyhexamethylene (bi)guanidine sulfonate; and polyoxyethylene guanidine salt.

9. The flame-retardant antibacterial agent according to claim 1, characterized in that the flame-retardant guanidine salt contains a flame-retardant element, and preferably contains phosphorus atom, halogen atom and/or nitrogen atom other than the nitrogen atom of the guanidine group, preferably, is at least one selected from the group consisting of guanidine phosphate, guanidine hydrochloride, guanidine hydrobromide, guanidine dihydrogen phosphate, diguanidine hydrogen phosphate, the phosphate, hydrochloride, hydrobromide, nitrate, carbonate, oxalate, sulfonate salts of aminoguanidine, and the above guanidine salt polymers; more preferably at least one selected from the group consisting of guanidine phosphate, guanidine hydrochloride, guanidine dihydrogen phosphate, diguanidine hydrogen phosphate, the phosphate, hydrochloride, hydrobromide, nitrate, sulfonate salts of aminoguanidine, polyhexamethylene (bi)guanidine hydrochloride and polyhexamethylene (bi)guanidine phosphate.

10. The flame-retardant antibacterial agent according to claim 1, characterized in that the flame-retardant guanidine salt comprises 30-100 wt %; preferably 50-100 wt %; more preferably 80-100 wt % of the total weight of the guanidine salt.

11. Method for the preparation of a flame-retardant antibacterial agent according to claim 1, comprising: subjecting maleic anhydride, the monomer M and the crosslinking agent to crosslinking copolymerization reaction in the presence of an initiator to prepare polymer microspheres, and contacting the polymer microspheres with a guanidine salt to graft the guanidine salt onto the polymer microspheres, thereby obtaining the flame-retardant antibacterial agent.

12. The method according to claim 11, characterized in that the polymer microspheres as the graft base are prepared by a self-stabilizing precipitation polymerization method.

13. The method according to claim 11, characterized in that the method comprises the following steps: (1) in an organic solvent and in the presence of a first portion of an initiator, contacting maleic anhydride and a first portion of the monomer M for a partial reaction, and then introducing a feed comprising a crosslinking agent for subsequent reaction, during which the reaction system comprises maleic anhydride, the monomer M and the crosslinking agent; wherein the feed comprising a crosslinking agent comprises the crosslinking agent, optionally a second portion of the monomer M and optionally a second portion of the initiator and optionally a solvent; (2) adding a guanidine salt to the product obtained in step (1) to continue the reaction, so that the guanidine salt is grafted on the surface of the product obtained in step (1).

14. The method according to claim 13, characterized in that the organic solvent is selected from organic acid alkyl esters, or mixtures of organic acid alkyl esters and alkanes or aromatic hydrocarbons; the organic acid alkyl ester is preferably at least one selected from the group consisting of methyl formate, ethyl formate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, amyl acetate, isoamyl acetate, benzyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, isobutyl butyrate, isoamyl butyrate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate and ethyl phenylacetate.

15. The method according to claim 13, characterized in that in said step (1), relative to 100 mol of maleic anhydride, the total amount of the first portion of the monomer M and the second portion of the monomer M in terms of terminal olefins is 50-150 mol; preferably, the molar ratio of the second portion of the monomer M to the first portion of the monomer M is (0-100):100; and/or relative to 100 mol of maleic anhydride, the amount of the crosslinking agent is 1-40 mol; and/or relative to 100 mol of maleic anhydride, the total amount of the first portion of the initiator and the second portion of the initiator is 0.05-10 mol; preferably, the molar ratio of the second portion of the initiator to the first portion of the initiator is (0-100):100.

16. The method according to claim 13, characterized in that the initiator is at least one selected from the group consisting of dibenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, dodecanoyl peroxide, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, azobisisobutyronitrile and azobisisoheptanenitrile.

17. The method according to claim 13, characterized in that in said step (1), the reaction by contacting the maleic anhydride with the first portion of the monomer M is carried out under an inert atmosphere at a temperature of 50 to 90° C. and a pressure of 0.3 to 1 MPa; and/or in said step (1), the subsequent reaction by introducing a feed comprising a crosslinking agent is carried out at a temperature of 50 to 90° C. and a pressure of 0.3 to 1 MPa.

18. The method according to claim 13, characterized in that in step (2), the reaction is carried out at a temperature of 0 to 100° C., preferably 2.5 to 90° C.; and/or in step (2), relative to 1000 g of maleic anhydride, the guanidine salt is used in an amount of 5 g to 5000 g, preferably 20 g to 3000 g, more preferably 100 g to 2000 g; preferably, the guanidine salt is added in the form of a solution, preferably an aqueous solution; and/or in step (2), the product obtained in step (1) reacts with the solution of the guanidine salt directly in the form of a suspension or after being dried.

19. (canceled)

20. A flame-retardant antibacterial thermoplastic resin composition, comprising a thermoplastic resin as the matrix, and a flame-retardant antibacterial agent according to claim 1, wherein, preferably, based on 100 parts by weight of the thermoplastic resin, the flame-retardant antibacterial agent is used in an amount of 0.05 to 4.0 parts by weight, preferably 0.1 to 2.8 parts by weight.

21. The flame-retardant antibacterial thermoplastic resin composition according to claim 20, characterized in that the composition further comprises an aluminum hypophosphite-based flame retardant and/or a halogen-containing flame retardant; wherein the aluminum hypophosphite-based flame retardant is preferably selected from the group consisting of inorganic aluminum hypophosphite and aluminum alkyl phosphinates (for example, at least one of aluminum diethylphosphinate, aluminum dipropylphosphinate, and aluminum phenylphosphinate) and combinations thereof; preferably selected from the group consisting of inorganic aluminum hypophosphite and aluminum diethylphosphinate and combinations thereof; preferably, based on 100 parts by weight of the thermoplastic resin, the amount of the aluminum hypophosphite-based flame retardant is 0 to 2.0 parts by weight, preferably 0.1 to 1.2 parts by weight; the halogen-containing flame retardant is preferably melamine hydrohalide, more preferably melamine hydrobromide; preferably, based on 100 parts by weight of the thermoplastic resin, the amount of the halogen-containing flame retardant is 0 to 2.0 parts by weight, preferably 0.1 to 1.2 parts by weight.

22. The flame-retardant antibacterial thermoplastic resin composition according to claim 20, characterized in that the composition further comprises a flame-retardant synergist and/or an anti-mildew agent, wherein the flame-retardant synergist is preferably selected from the group consisting of 2,3-dimethyl-2,3-diphenylbutane, paracumene polymer and combination thereof; preferably, based on 100 parts by weight of the thermoplastic resin, the amount of the flame-retardant synergist is 0 to 1.0 parts by weight, preferably 0.05 to 1 parts by weight; the anti-mildew agent is preferably at least one selected from the group consisting of: pyrithiones, for example, at least one selected from the group consisting of zinc pyrithione, copper pyrithione and bispyrithione; isothiazolinones, for example, at least one selected from the group consisting of 2-methyl-1-isothiazolin-3-one (MIT), 5-chloro-2-methyl-1-isothiazolin-3-one (CMIT), 2-n-octyl-4-isothiazolin-3-one (OIT), 4,5-dichloro-2-n-octyl-3-isothiazolinone (DCOIT), 1,2-benzisothiazolin-3-one (BIT), 4-methyl-1,2-benzisothiazolin-3-one (MBIT), and 4-n-butyl-1,2-benzisothiazolin-3-one (BBIT); 10,10′-oxybisphenoxarsine (OBPA); 3-iodo-2-propynyl-butyl-carbamate (IPBC); 2,4,4′-trichloro-2′-hydroxydiphenyl ether; and 2-(thiazol-4-yl) benzimidazole; preferably, based on 100 parts by weight of the thermoplastic resin, the anti-mildew agent is used in an amount of 0 to 5.0 parts by weight, preferably 0.05 to 4.0 parts by weight.

23. The flame-retardant antibacterial thermoplastic resin composition according to claim 20, characterized in that the thermoplastic resin is selected from the group consisting of polyolefins (for example, at least one of polyethylene and polypropylene and copolymers thereof), polystyrene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, polyoxymethylene, nylon, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polycarbonate, polyphenylene oxide, polyphenylene sulfide, and polymer alloys or mixtures formed by one or more of the above thermoplastic resins.

24. The flame-retardant antibacterial thermoplastic resin composition according to claim 20, characterized in that the composition further comprises at least one functional additive selected from the group consisting of antioxidants, light stabilizers, toughening agents, compatibilizers, pigments, and dispersants.

25. An Article, prepared from the flame-retardant antibacterial thermoplastic resin composition according to claim 20, especially in the form of fibers, films and fabrics, e.g., nonwoven fabrics, and particularly those used for schools, hospitals, hotels, smart home appliances and new energy vehicles.

Description

EXAMPLES

[0084] In the following, the present invention is further illustrated in combination with the examples, but without being limited by these examples.

[0085] 1) Sources of Starting Materials

[0086] Polyethylene (PE): brand 7042, Maoming Petrochemical, China

[0087] Polypropylene (PP): GD-H-230, Cangzhou Refining & Chemical, China

[0088] Nylon 6: brand B3S, BASF

[0089] PC: polycarbonate, brand 3103, Bayer

[0090] ABS: acrylonitrile/butadiene/styrene copolymer, brand 3504, Shanghai Gaoqiao, China

[0091] Polyhexamethyleneguanidine phosphate: Foshan Lanfeng Additives, China

[0092] Guanidine dihydrogen phosphate: Beshine (Beijing) Chemical Technology Co., Ltd., China

[0093] Guanidine hydrobromide: SHANGHAI ZZBIO CO., LTD, China

[0094] Aminoguanidine nitrate: Guangdong Wengjiang Chemical, China

[0095] Bicumyl: Guangzhou Xijia Chemical, China

[0096] Melamine hydrobromide: Guangzhou Xijia Chemical, China

[0097] Aluminum hypophosphite: Guangzhou Xijia Chemical, China

[0098] Zinc pyrithione, copper pyrithione: Zhufeng Fine Chemical Co., Ltd., China

[0099] Compounded antioxidant: obtained by homogeneously mixing antioxidant 1010 (BASF), antioxidant 168 (BASF), and calcium stearate (Shandong Hao Na, China) in the mass ratio of 2/2/1

[0100] Silver-supporting zeolite antibacterial agent: Xi'an Conval Antibacterial Technology Co., Ltd., China

[0101] 2) Test Methods and Equipment

[0102] Average particle diameter of the microspheres: characterized by the number-average particle diameter, as measured by the S-4800 scanning electron microscope from the Hitachi Company, Japan.

[0103] Tensile strength: determined according to standard GB/T1040-2006.

[0104] Flexural modulus: determined according to standard GB/T 9341-2008.

[0105] Antibacterial test: tested according to standard GB/T 31402-2015. Specifically, the antibacterial test adopted the film sticking method, and the operation steps were as follows: after sterilization, the sample to be tested was inoculated on its surface with a bacterial suspension, and covered with a polyethylene film, so that a uniform liquid film was formed between the sample and the film. After being cultured under certain conditions, elution was performed, followed by dilution to an appropriate concentration gradient; a certain volume was taken to spread in the culture medium for re-culturing and the number of viable bacteria was determined to calculate the antibacterial rate.

[0106] Vertical burning test (UL-94): tested according to standard GN/T 2408-2008. The flammability of the specimen was tested by the CZF-2 vertical flammability tester (Shangyuan Instruments, Nanjing, China). The specimen was a bar sample of 120 mm×10 mm×10 mm.

[0107] The specific rating standard for the UL-94 test is shown below.

TABLE-US-00001 Burning behavior of specimens V-0 V-1 V-2 Afterflame time for each individual specimen after <10 <30 <30 flame application (s) Afterglow time for each individual specimen after <30 <60 <60 the second flame application (s) Afterflame time for each set of 5 specimens after <50 <250 <250 10 flame applications (s) Afterflame or afterglow of any specimen up to the No No No holding clamp Absorbent cotton ignited by flaming drips of any No No Yes specimen

[0108] HB level: the lowest flame retardant level in the UL-94 standard. The requirements include a burning rate of less than 40 mm per minute for specimens having a thickness of 3-13 mm; a burning rate of less than 70 mm per minute for specimens having a thickness less than 3 mm; or ceasing to burn before the 100 mm reference mark.

[0109] If the specimen fails to reach the HB level, it is reported as no rating (NR).

[0110] Limiting oxygen index (LOI value) experiment: tested according to standard GB/T 2406.1-2008.

[0111] Glow wire flammability index experiment: tested according to standard GB/T5961.11-2006.

[0112] Crosslinking degree: the crosslinking degree of the microspheres was characterized by gel content, as measured by a solvent extraction method. The specific method was as follows: weighing the sample to be tested as W.sub.1, then placing the sample to be tested in acetone of 5 times the weight thereof, extracting it at 50° C. for 30 min, and after the completion of the extraction, drying and weighing the sample as W.sub.2. The crosslinking degree is calculated as W.sub.2/W.sub.1×100%. The content of dissolving-out substances is calculated as (1−W.sub.2/W.sub.1)×100%.

[0113] 1. Preparation of Guanidine Salt Flame-Retardant Antibacterial Microspheres (Flame-Retardant Antibacterial Agent)

Example 1

[0114] (1) The C.sub.4 fraction from the ethylene cracking process of the Sinopec Zhenhai Refining & Chemical, China, was used. The C.sub.4 fraction was a mixed butene gas having the following composition: trans-2-butene: 40.83% by weight; cis-2-butene: 18.18% by weight; n-butane: 24.29% by weight; n-butene: 9.52% by weight; isobutene: 2.78% by weight; and others: 4.4% by weight. In an autoclave, 100 g of maleic anhydride and 2 g of azobisisobutyronitrile were dissolved in 800 mL of isoamyl acetate to form solution 1, and the well metered mixed butenes (wherein the molar ratio of maleic anhydride to the effective component (terminal olefins) in the mixed olefins was 1:1) were passed thereinto. The reaction was performed at 70° C. and 0.5 MPa for 1 hour under a nitrogen atmosphere.

[0115] (2) 25 g of divinylbenzene was dissolved in 200 mL of isoamyl acetate to prepare solution 2. Solution 2 was added dropwise to the reaction system obtained in (1) by a plunger pump for 2 hours. After the completion of the dropwise addition, the reaction system continued to react for 3 hours while maintaining the temperature.

[0116] (3) After the above reaction, the autoclave was decompressed, and 200 g of an aqueous solution of guanidine dihydrogen phosphate (15 wt %) and 200 g of an aqueous solution of polyhexamethylene biguanide hydrochloride (15 wt %) were added for reaction at 80° C. for 3 hours. The system after the reaction was left to stand for layering, wherein the heavy phase was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, and the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; again, the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; and the resulting solid was dried under vacuum to obtain the flame-retardant antibacterial agent, i.e., polymer microspheres #1 grafted with guanidine salt on the surface. The average particle diameter of the obtained polymer microspheres was 1280 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 5.5%, and correspondingly, the crosslinking degree was 94.5%.

Example 2

[0117] The flame-retardant antibacterial agent was prepared as in Example 1, except that the system after the reaction in step (2) was centrifuged by a centrifuge at 5000 rad/min for 30 minutes to obtain crosslinked mixed butene/maleic anhydride polymer microspheres, which were purified by washing with n-hexane and dried under vacuum. Then, the dried crosslinked mixed butene/maleic anhydride polymer microspheres were added to 400 g of a mixed aqueous solution of guanidine dihydrogen phosphate (20 wt %) and polyhexamethylene biguanide hydrochloride (20 wt %) and reacted at 80° C. for 3 hours. The system after the reaction was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; again, the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; and the resulting solid was dried under vacuum to obtain the flame-retardant antibacterial agent, i.e., polymer microspheres #2 grafted with guanidine salt on the surface. The average particle diameter of the obtained polymer microspheres was 1310 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 5.6%, and correspondingly, the crosslinking degree was 94.4%.

Example 3

[0118] (1) In an autoclave, 100 g of maleic anhydride and 2 g of azobisisobutyronitrile were dissolved in 800 mL of isoamyl acetate to form solution 1, and the well metered mixed butenes (whose composition was the same as that in Example 1, and wherein the molar ratio of maleic anhydride to the effective component (terminal olefins) in the mixed olefins was 1:1) were passed thereinto. The reaction was performed at 70° C. and 0.4 MPa for 2 hours under a nitrogen atmosphere.

[0119] (2) 15 g of divinylbenzene was dissolved in 200 mL of isoamyl acetate to prepare solution 2. Solution 2 was added dropwise to the reaction system by a plunger pump for 2 hours. After the completion of the dropwise addition, the reaction system continued to react for 3 hours while maintaining the temperature.

[0120] (3) After the above reaction, the autoclave was decompressed, and 200 g of an aqueous solution of guanidine hydrobromide (20 wt %) and 200 g of an aqueous solution of polyhexamethyleneguanidine phosphate (20 wt %) were added separately for reaction at 60° C. for 7 hours. The system after the reaction was left to stand for layering, wherein the heavy phase was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, the obtained solid was washed with 4 L of water under stirring, and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; again, the obtained solid was washed with 4 L of water under stirring, and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; and the resulting solid was dried under vacuum to obtain the flame-retardant antibacterial agent, i.e., polymer microspheres #3 grafted with guanidine salt on the surface. The average particle diameter of the obtained polymer microspheres was 1210 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 6.5%, and correspondingly, the crosslinking degree was 93.5%.

Example 4

[0121] (1) In an autoclave, 100 g of maleic anhydride and 1.5 g of azobisisobutyronitrile were dissolved in 800 mL of isoamyl acetate to form solution 1, and the well metered mixed butenes (whose composition was the same as that in Example 1, and wherein the molar ratio of maleic anhydride to the effective component (terminal olefins) in the mixed olefins was 1:0.75) were passed thereto. The reaction was performed at 70° C. and 0.5 MPa for 1 hour under a nitrogen atmosphere.

[0122] (2) 0.5 g of azobisisobutyronitrile and 18 g of divinylbenzene were dissolved in 200 mL of isoamyl acetate to prepare solution 2. Solution 2 was added dropwise to the reaction system by a plunger pump for 2 hours. After the completion of the dropwise addition, the reaction system continued to react for 3 hours while maintaining the temperature.

[0123] (3) After the above reaction, the autoclave was decompressed, and 200 g of an aqueous solution of guanidine dihydrogen phosphate (20 wt %), 200 g of an aqueous solution of guanidine hydrobromide (20 wt %) and 200 g of an aqueous solution of polyhexamethylene guanidine phosphate (20 wt %) were added separately and reacted at 60° C. for 10 hours. The system after the reaction was left to stand for layering, wherein the heavy phase was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; again, the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; and the resulting solid was dried under vacuum to obtain the flame-retardant antibacterial agent, i.e., polymer microspheres #4 grafted with guanidine salt on the surface. The average particle diameter of the obtained polymer microspheres was 1510 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 5.8%, and correspondingly, the crosslinking degree was 94.2%.

Example 5

[0124] (1) The C.sub.5 fraction from the ethylene cracking process of the Sinopec Zhenhai Refining & Chemical, China, was used. The mixed gas of the C.sub.5 fraction had the following composition: diolefins (isoprene, cyclopentadiene, 1,4-pentadiene, piperylene): 47.83% by weight; monoolefins (1-pentene, 2-pentene, cyclopentene, 2-methyl-1-butene, 2-methyl-2-butene): 13.18% by weight; alkanes (n-pentane, isopentane, cyclopentane, 2-methylbutane): 21.29% by weight; alkynes (but-2-yne, 3-penten-1-yne): 0.92% by weight; and others: 16.78% by weight. In an autoclave, 100 g of maleic anhydride and 2 g of azobisisobutyronitrile were dissolved in 800 mL of isoamyl acetate to form solution 1, and the well metered mixed C.sub.5 (wherein the molar ratio of maleic anhydride to the effective component (terminal olefins) in the mixed olefins was 1:0.5) was passed thereinto. The reaction was performed at 70° C. and 0.5 MPa for 1 hour under a nitrogen atmosphere.

[0125] (2) The well metered C.sub.5 fraction (wherein the molar ratio of maleic anhydride to the effective component (terminal olefins, including diolefins) in said part of mixed olefins was 1:0.5) and 15 g of divinylbenzene were dissolved in 200 mL of isoamyl acetate to prepare solution 2, the solution 2 was added dropwise to the reaction system by a plunger pump for 2 hours. After the completion of the dropwise addition, the reaction system continued to react for 3 hours while maintaining the temperature.

[0126] (3) After the above reaction, the autoclave was decompressed, and the system was left to stand for layering, wherein the heavy phase was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, the obtained solid was washed with 400 mL of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; again, the obtained solid was washed with 400 mL of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes and the resulting solid was dried under vacuum to obtain crosslinked mixed pentene/maleic anhydride polymer microspheres.

[0127] (4) 100 g of the crosslinked mixed pentene/maleic anhydride polymer microsphere was added to 400 g of a mixed solution of aminoguanidine nitrate (15 wt %) and polyhexamethylene biguanide phosphate (15 wt %) and reacted at 50° C. for 6 hours. The system after the reaction was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, and the obtained solid was washed with 4 L of water under stirring and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; again, the obtained solid was washed with 4 L of water under stirring, and centrifuged by a centrifuge at 5000 rad/min for 20 minutes; and the resulting solid was dried under vacuum to obtain the flame-retardant antibacterial agent, i.e., polymer microspheres #5 grafted with guanidine salt on the surface. The average particle diameter of the obtained polymer microspheres was 1458 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 5.6%, and correspondingly, the crosslinking degree was 94.4%.

Example 6

[0128] A flame-retardant antibacterial agent was prepared as in Example 5, except that the amount of divinylbenzene in step (2) was changed to 10 g, and finally polymer microspheres #6 were obtained. The average particle diameter of the obtained polymer microspheres was 1200 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 7.0%, and correspondingly, the crosslinking degree was 93.0%.

Example 7

[0129] The flame-retardant antibacterial agent was prepared as in Example 1, except that the divinylbenzene in step (1) was replaced with 36.0 g of pentaerythritol tetraacrylate, and finally polymer microspheres #7 were obtained. The average particle diameter of the obtained polymer microspheres was 1320 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 5.2%, and correspondingly, the crosslinking degree was 94.8%.

[0130] 2. Preparation and Property Comparison of Flame-Retardant Antibacterial Thermoplastic Resin Compositions and Comparative Resin Compositions

[0131] The formulations of the resin compositions used in the Examples and Comparative Examples are shown in Table 1, and the amounts in Table 1 are all in parts by weight. The properties of the resin compositions prepared in the Examples and Comparative Examples are shown in Table 2.

Example 8

[0132] 100 parts by weight of polypropylene, 1.0 parts by weight of the polymer microspheres #1, 0.2 parts by weight of aluminum hypophosphite, 0.35 parts by weight of MHB (melamine hydrobromide), 0.1 parts by weight of the flame-retardant synergist DMDPB (bicumyl), 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Comparative Example 1

[0133] 100 parts by weight of polypropylene and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Comparative Example 2

[0134] 100 parts by weight of polypropylene, 1.0 parts by weight of the silver-supporting zeolite antibacterial agent, 0.2 parts by weight of aluminum hypophosphite, 0.35 parts by weight of MHB, 0.1 parts by weight of the flame-retardant synergist DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Example 9

[0135] 100 parts by weight of polypropylene, 1.0 parts by weight of the polymer microspheres #2, 0.2 parts by weight of aluminum hypophosphite, 0.35 parts by weight of MHB, 0.1 parts by weight of the flame-retardant synergist DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Example 10

[0136] 100 parts by weight of polypropylene, 0.9 parts by weight of the polymer microspheres #3, 0.25 parts by weight of aluminum hypophosphite, 0.2 parts by weight of MHB, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Example 11

[0137] 100 parts by weight of polypropylene, 1.6 parts by weight of the polymer microspheres #4, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Comparative Example 3

[0138] 100 parts by weight of polypropylene, 1.6 parts by weight of the silver-supporting zeolite antibacterial agent, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Example 12

[0139] 100 parts by weight of polypropylene, 1.0 parts by weight of the polymer microspheres #5, 0.25 parts by weight of aluminum hypophosphite, 0.3 parts by weight of MHB, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

Example 13

[0140] 100 parts by weight of polypropylene, 1.0 parts by weight of the polymer microspheres #6, 0.25 parts by weight of aluminum hypophosphite, 0.3 parts by weight of MHB, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines for flame-retardant, antibacterial and mechanical property tests.

Example 14

[0141] 100 parts by weight of polypropylene, 1.2 parts by weight of the polymer microspheres #7, 0.2 parts by weight of aluminum hypophosphite, 0.3 parts by weight of MHB, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines for flame-retardant, antibacterial and mechanical property tests.

Example 15

[0142] 100 parts by weight of polyethylene, 2 parts by weight of the polymer microspheres #1, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 175° C. to 205° C. (175° C., 190° C., 205° C., 205° C., 200° C., and 195° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 190 to 200° C. into samples for flame-retardant and antibacterial tests.

Comparative Example 4

[0143] 100 parts by weight of polyethylene and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 175° C. to 205° C. (175° C., 190° C., 205° C., 205° C., 200° C., and 195° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 190 to 200° C., into samples for flame-retardant and antibacterial tests.

Example 16

[0144] 100 parts by weight of nylon 6, 2.5 parts by weight of the polymer microspheres #2, 0.3 parts by weight of zinc pyrithione and 0.3 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 220° C. to 240° C. (220° C., 230° C., 240° C., 240° C., 240° C., and 240° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 230 to 240° C. into samples for flame-retardant and antibacterial tests.

Comparative Example 5

[0145] 100 parts by weight of nylon 6 and 0.3 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 220° C. to 240° C. (the temperatures of the various zones: 220° C., 230° C., 240° C., 240° C., 240° C., and 240° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The extruded pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 230 to 240° C. into samples for flame-retardant and antibacterial tests.

Example 17

[0146] 80 parts by weight of PC, 20 parts by weight of ABS, 4 parts by weight of the polymer microspheres #4, 0.3 parts by weight of zinc pyrithione and 0.3 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 230° C. to 260° C. (the temperatures of the various zones: 230° C., 240° C., 255° C., 260° C., 255° C., and 240° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 230 to 240° C. into samples for flame-retardant and antibacterial tests.

Comparative Example 6

[0147] 80 parts by weight of PC, 20 parts by weight of ABS and 0.3 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 230° C. to 260° C. (the temperatures of the various zones: 230° C., 240° C., 255° C., 260° C., 255° C., and 240° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 230 to 240° C. into samples for flame-retardant and antibacterial tests.

Example 18

[0148] 100 parts by weight of polypropylene, 1.6 parts by weight of the polymer microspheres #4 and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 19

[0149] 100 parts by weight of polypropylene, 5 parts by weight of the polymer microspheres #4 and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Comparative Example 7

[0150] 1. (1) The C.sub.4 fraction from the ethylene cracking process of the Sinopec Zhenhai Refining & Chemical, China, was used. The C.sub.4 fraction was a mixed butene gas having the following composition: trans-2-butene: 40.83% by weight; cis-2-butene: 18.18% by weight; n-butane: 24.29% by weight; n-butene: 9.52% by weight; isobutene: 2.78% by weight; and others: 4.4% by weight. In an autoclave, 100 g of maleic anhydride and 2 g of azobisisobutyronitrile were dissolved in 800 mL of isoamyl acetate to form solution 1, and the well metered mixed butenes (wherein the molar ratio of maleic anhydride to the effective component (terminal olefins) in the mixed olefins was 1:1) were passed thereinto for reaction at 70° C. and 0.5 MPa for 1 hour under a nitrogen atmosphere.

[0151] (2) 25 g of divinylbenzene was dissolved in 200 mL of isoamyl acetate to prepare solution 2. Solution 2 was added dropwise to the reaction system obtained in (1) by a plunger pump for 2 hours. After the completion of the dropwise addition, the reaction system continued to react for 3 hours while maintaining the temperature.

[0152] (3) After the above reaction, the autoclave was decompressed, and the system was left to stand for layering, the heavy phase was centrifuged by a centrifuge at 5000 rad/min for 20 minutes, the obtained solid was dried under vacuum to obtain the polymer microspheres #8 which was not grafted with guanidine salt on the surface. The average particle diameter of the obtained polymer microspheres was 1200 nm. The weight percentage of the dissolving-out substances from the obtained polymer microspheres in acetone of 5 times the weight thereof at 50° C. for 30 min was 5.5%, and correspondingly, the crosslinking degree was 94.5%.

[0153] 2. 100 parts by weight of polypropylene, 5 parts by weight of the polymer microspheres #8 and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 20

[0154] 100 parts by weight of polypropylene, 1 part by weight of the polymer microspheres #4, 0.2 parts by weight of aluminum hypophosphite, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 21

[0155] 100 parts by weight of polypropylene, 1 part by weight of the polymer microspheres #4, 0.2 parts by weight of aluminum hypophosphite, 0.1 parts by weight of DMDPB, 0.2 parts by weight of zinc pyrithione and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 22

[0156] 100 parts by weight of polypropylene, 1 part by weight of the polymer microspheres #4, 0.2 parts by weight of MHB, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 23

[0157] 100 parts by weight of polypropylene, 1.6 parts by weight of the polymer microspheres #4, 0.2 parts by weight of aluminum hypophosphite, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 24

[0158] 100 parts by weight of polypropylene, 1.8 parts by weight of the polymer microspheres #4, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Comparative Example 8

[0159] 100 parts by weight of polypropylene, 1.8 parts by weight of aluminum hypophosphite, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 25

[0160] 100 parts by weight of polypropylene, 1 part by weight of the polymer microspheres #4, 0.1 parts by weight of aluminum hypophosphite, 0.1 parts by weight of MHB, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Comparative Example 9

[0161] 100 parts by weight of polypropylene, 1.8 parts by weight of MHB, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Example 26

[0162] 100 parts by weight of polypropylene, 1.6 parts by weight of the polymer microspheres #4, 0.2 parts by weight of MHB, 0.1 parts by weight of DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the temperatures of the various zones of the extruder being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C. and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant and antibacterial tests.

Comparative Example 10

[0163] 100 parts by weight of polypropylene, 0.2 parts by weight of aluminum hypophosphite, 0.35 parts by weight of MHB, 0.1 parts by weight of the flame-retardant synergist DMDPB and 0.25 parts by weight of the compounded antioxidant were charged into a high-speed mixer and sufficiently and homogeneously stirred, and then the mixed mass was melt blended through a twin-screw extruder, with the extruder temperature being 190° C. to 220° C. (the temperatures of the various zones being: 190° C., 210° C., 220° C., 220° C., 215° C., and 210° C.) and the rotating speed being 350 r.p.m., and extruded and pelletized. The obtained pellets were dried in a thermostatic oven at 90° C. for 3 hrs, and then, injection molded at an injection molding temperature of 200 to 220° C. into standard splines of specified size for flame-retardant, antibacterial and mechanical property tests.

TABLE-US-00002 TABLE 1 Formulations of compositions of Examples and Comparative Examples Flame-retardant Matrix resin Antibacterial agent Flame retardant synergist Anti-mildew agent Items Type Amount Type Amount Type Amount Type Amount Type Amount Example 8 PP 100 Microspheres 1 Aluminum 0.2 DMDPB 0.1 Zinc 0.2 #1 hypophosphite pyrithione MHB 0.35 Example 9 PP 100 Microspheres 1 Aluminum 0.2 DMDPB 0.1 Zinc 0.2 #2 hypophosphite pyrithione MHB 0.35 Example 10 PP 100 Microspheres 0.9 Aluminum 0.25 DMDPB 0.1 Zinc 0.2 #3 hypophosphite pyrithione MHB 0.2 Example 11 PP 100 Microspheres 1.6     DMDPB 0.1 Zinc 0.2 #4     pyrithione Example 12 PP 100 Microspheres 1 Aluminum 0.25 DMDPB 0.1 Zinc 0.2 #5 hypophosphite pyrithione MHB 0.3 Example 13 PP 100 Microspheres 1 Aluminum 0.25 DMDPB 0.1 Zinc 0.2 #6 hypophosphite pyrithione MHB 0.3 Example 14 PP 100 Microspheres 1.2 Aluminum 0.2 DMDPB 0.1 Zinc 0.2 #7 hypophosphite pyrithione MHB 0.3 Comparative PP 100 —               Example 1 Comparative PP 100 Silver- 1 Aluminum 0.2 DMDPB 0.1 Zinc 0.2 Example 2 supporting hypophosphite pyrithione zeolite MHB 0.35 Comparative PP 100 Silver- 1.6     DMDPB 0.1 Zinc 0.2 Example 3 supporting pyrithione zeolite Example 15 PE 100 Microspheres 2         Zinc 0.2 #1 pyrithione Comparative PE 100                 Example 4 Example 16 PA 100 Microspheres 2.5         Zinc 0.3 #2 pyrithione Comparative PA 100                 Example 5 Example 17 PC 80 Microspheres 4         Zinc 0.3 ABS 20 #4 pyrithione Comparative PC 80                 Example 6 ABS 20 Example 18 PP 100 Microspheres 1.6             #4 Example 19 PP 100 Microspheres 5             #4 Comparative PP 100 #8(blank 5             Example 7 microspheres) Example 20 PP 100 Microspheres 1 Aluminum 0.2 DMDPB 0.1     #4 hypophosphite Example 21 PP 100 Microspheres 1 Aluminum 0.2 DMDPB 0.1 Zinc 0.2 #4 hypophosphite pyrithione Example 22 PP 100 Microspheres 1 MHB 0.2 DMDPB 0.1     #4 Example 23 PP 100 Microspheres 1.6 Aluminum 0.2 DMDPB 0.1     #4 hypophosphite Example 24 PP 100 Microspheres 1.8     DMDPB 0.1     #4 Comparative PP 100     Aluminum 1.8 DMDPB 0.1     Example 8 hypophosphite Example 25 PP 100 Microspheres 1 Aluminum 0.1 DMDPB 0.1     #4 hypophosphite MHB 0.1 Comparative PP 100     MHB 1.8 DMDPB 0.1     Example 9 Example 26 PP 100 Microspheres 1.6 MHB 0.2 DMDPB 0.1     #4 Comparative PP 100     Aluminum 0.2 DMDPB 0.1     Example 10 hypophosphite MHB 0.35

TABLE-US-00003 TABLE 2 Comparison of properties of compositions of Examples and Comparative Examples Limit Glow wire Tensile Flexural Antibacterial test Vertical oxygen flammability strength/ modulus/ Escherichia Staphylococcus Burn index/% index Items MPa GPa coli aureus UL-94 (LOI value) 750° C. Example 8 34.6 1.54 99.9% 99.9% V-2 24.0 Passed Example 9 35.1 1.52 99.9% 99.9% V-2 23.8 Passed Example 10 34.7 1.55 99.9% 99.9% V-2 24.5 Passed Example 11 34.9 1.49 99.9% 99.9% V-2 24.2 Passed Example 12 33.9 1.52 99.9% 99.9% V-2 23.7 Passed Example 13 34.1 1.53 99.9% 99.9% V-2 24.5 Passed Example 14 34.5 1.55 99.9% 99.9% V-2 24.3 Passed Comparative 34.5 1.43   0%   0% NR 19.9 Failed Example 1 Comparative 31.0 1.45 99.9% 99.9% NR 22.5 Failed Example 2 Comparative 32.9 1.48 99.9% 99.9% NR 20.5 Failed Example 3 Example 15 —   99.9% 99.9% HB 19.8   Comparative       0%   0% NR 17   Example 4 Example 16     99.9% 99.9% V-2 26.8   Comparative       0%   0% V-2 24   Example 5 Example 17     99.9% 99.9% V-2 25.6   Comparative       0%   0% NR 24   Example 6 Example 18     99.9% 99.9% HB 23   Example 19     99.9% 99.9% V2 24   Comparative       0%   0% NR 19.5   Example 7 Example 20     99.9% 99.9% V-2 22.5   Example 21     99.9% 99.9% V-2 22.0   Example 22     99.9% 99.9% V-2 22.5   Example 23     99.9% 99.9% V-2 25.5   Example 24     99.9% 99.9% HB 23.5   Comparative       0%   0% HB 24   Example 8 Example 25     99.9% 99.9% V-2 24   Comparative       0%   0% HB 23.5   Example 9 Example 26     99.9% 99.9% V-2 25   Comparative 34.6 1.44   0%   0% HB 23 Failed Example 10 in Table 2 means undetermined.

[0164] It can be seen from the test results in Table 1 and Table 2 that PP resin itself is very easy to burn and does not have antibacterial property.

[0165] Examples 8 to 14 and 18 to 26 are the flame-retardant antibacterial PP compositions according to the present invention using the flame-retardant antibacterial microspheres of the present invention. It can be seen from Table 2 that the PP compositions according to the present invention have not only an excellent antibacterial property, but also can reach the HB level or even V-2 level of the UL-94 test with a low addition amount of the flame retardant, showing a good self-extinguishing property. In Examples 8-14, the compositions are tested to have passed the glow wire flammability index test at 750° C.

[0166] It can also be seen from the test results of Examples 8-14 that the PP compositions according to the present invention not only have flame-retardant and antibacterial properties, but also have improved tensile strength and/or flexural modulus compared with PP alone (Comparative Example 1), and have overcome the technical difficulty in the prior art regarding reduced comprehensive performance of materials due to the poor dispersibility of the flame retardant and the antibacterial agent in the matrix.

[0167] From comparison of Example 11 with Comparative Example 3, Example 24 with Comparative Examples 8 and 9, and Example 8 with Comparative Example 2, it can be seen that under the same addition amount of flame-retardant and antibacterial additives, the compositions using the flame-retardant antibacterial microspheres of the present invention have more excellent flame-retardant and antibacterial comprehensive performance than the compositions using the antibacterial agent alone, the flame retardant alone or the combination of the flame retardant and the antibacterial agent in the prior art.

[0168] From comparison of Example 23, Example 24 and Comparative Example 8, or comparison of Example 24, Example 26 and Comparative Example 9, it can be seen that when the flame-retardant antibacterial microspheres according to the present invention are used in combination with the aluminum hypophosphite-based flame retardant or halogen-containing flame retardant, a synergistic effect is produced through the establishment of a hybrid carbon layer structure, and the obtained flame-retardant and antibacterial properties are remarkably better than the use of a single component in the same addition amount.

[0169] From comparison of Examples 20, 22 and 25, it can be seen that in the case of adding aluminum hypophosphite-based flame retardant and halogen-containing flame retardant simultaneously, a better synergistic flame-retardant effect is obtained compared with adding aluminum hypophosphite-based flame retardant or halogen-containing flame retardant separately.

[0170] From comparison of the results of Examples 18, 19 and 11, it can be seen that in the case of adding a flame-retardant synergist and an anti-mildew agent, the flame-retardant and antibacterial efficiencies of the flame-retardant antibacterial microspheres of the present invention can be increased, so that a higher flame-retardant level can be reached with a lower addition amount.

[0171] From comparison of Examples 15-17 and Comparative Examples 4-6, it can be seen that the flame-retardant antibacterial microspheres of the present invention also improve the flame-retardant and antibacterial properties of materials in other matrix resins, such as PE, PA and PC/ABS.

[0172] From comparison of Comparative Example 2 and Comparative Example 10, it can be seen that the addition of the existing silver antibacterial agent decreases both the flame retardancy and the tensile strength of the resin composition added with a flame retardant.

[0173] To sum up, the single-component flame-retardant antibacterial microspheres of the present invention not only have high flame-retardant and antibacterial efficiencies, but also can achieve a synergistic effect with the flame retardants in the prior art, and further have a good dispersibility in the matrix, thereby overcoming the technical difficulty in the prior art regarding decreased comprehensive performance of materials due to the poor dispersibility of the flame retardant and the antibacterial agent in the matrix.

[0174] While the present invention has been described in detail and illustrated by way of examples, other modifications and changes within the spirit and scope of the present invention will be apparent to a person skilled in the art. Furthermore, it is to be understood that various aspects, various parts of different embodiments, and various features listed in the present invention may be combined or replaced in whole or in part. In addition, a person skilled in the art will appreciate that the above description is by way of example only and is not intended to limit the present invention.