Composition and method for producing the same, and powder coating material, pellet, resin formed article, and electric wire

Abstract

The present invention provides a composition including a fluorine-containing polymer, and excellent in heat resistance even if only a small amount of additives is added to the composition. The present invention relates to a composition, comprising: a fluorine-containing polymer (a) and a cobalt compound (b).

Claims

1. A composition, comprising: a fluorine-containing polymer (a) and a cobalt compound (b), wherein the fluorine-containing polymer (a) includes a polymerization unit based on at least one monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl ether), chlorotrifluoroethylene, vinylidene fluoride, and vinyl fluoride, wherein the cobalt compound (b) is at least one selected from the group consisting of cobalt acetate, cobalt benzoate, and organometallic complexes of cobalt, and wherein an amount of the cobalt compound (b) is 1 to 100 ppm of the fluorine-containing polymer (a).

2. The composition according to claim 1, wherein the cobalt compound (b) is a tetrapyrrole cyclic compound.

3. The composition according to claim 1, wherein the cobalt compound (b) is an organometallic complex in which a ligand having a porphyrin ring or a phthalocyanine ring makes coordinate bonds with a cobalt atom.

4. The composition according to claim 1, wherein the cobalt compound (b) is phthalocyanine cobalt.

5. The composition according to claim 1, wherein the cobalt compound (b) is cobalt acetylacetonate.

6. The composition according to claim 1, wherein an amount of the cobalt compound (b) is 1 to 50 ppm of the fluorine-containing polymer (a).

7. The composition according to claim 1, wherein the fluorine-containing polymer (a) is at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymers, ethylene/tetrafluoroethylene copolymer, ethylene/tetrafluoroethylene/hexafluoropropylene copolymer, polychlorotrifluoroethylene, chlorotrifluoroethylene/tetrafluoroethylene copolymer, ethylene/chlorotrifluoroethylene copolymer, polyvinylidene fluoride, tetrafluoroethylene/vinylidene fluoride copolymer, vinylidene fluoride/hexafluoropropylene/tetrafluoroethylene copolymer, vinylidene fluoride/hexafluoropropylene copolymer, and polyvinyl fluoride.

8. The composition according to claim 1, wherein the fluorine-containing polymer (a) is at least one selected from the group consisting of ethylene/tetrafluoroethylene copolymer and ethylene/tetrafluoroethylene/hexafluoropropylene copolymer.

9. The composition according to claim 1, further comprising a titanium oxide.

10. A powder coating material, comprising the composition according to claim 1.

11. A pellet, comprising the composition according to claim 1.

12. A resin formed article formed from the composition according to claim 1.

13. An electric wire, comprising: a core wire; and a covering material made of the composition according to claim 1, covering the core wire.

14. A method for producing the composition according to claim 1, the method comprising: preparing a masterbatch for resin forming including the fluorine-containing polymer (a), and the cobalt compound (b) in an amount of 0.1% by mass or more of the amount of the fluorine-containing polymer (a) by mixing the fluorine-containing polymer (a) and the cobalt compound (b), preparing the composition according to claim 1 by adding the fluorine-containing polymer (a) to the masterbatch for resin forming.

Description

MODES FOR CARRYING OUT THE INVENTION

(1) The present invention is more specifically described based on Examples. It is noted that the present invention is not limited to these Examples.

Example 1

(2) A copolymer powder having a melt flow rate of 26 g/10 min at 297 C. and having a molar ratio of ethylene:TFE:(perfluorobutyl)ethylene of 42.6:56.2:1.2 was made into a sheet using a roller compactor, and the sheet was crushed into granular materials, each having a size of about 2 mm. The materials were ground and classified using an atomizer grinding machine. Thus, a copolymer powder having an average particle size of 220 m and a bulk density of 0.70 g/ml was prepared. Cobalt acetate was added to the copolymer powder, as a cobalt compound, in an amount of 0.001 parts by mass relative to 100 parts by mass of the copolymer powder. The mixture was uniformly dispersed using a Henschel Mixer to prepare a powder coating material. The melt flow rate of the copolymer was the value determined in accordance with ASTM D3159 at a temperature of 297 C. at a load of 5 kgf. The melt flow rates in Examples and Comparative Examples described below were similarly determined.

(3) A heat resistance test was performed as follows. The powder coating material prepared was put on an aluminum plate having a size of 100 mm long by 200 mm wide by 2 mm thick to prepare a powder bed having a size of 50 mm long by 50 mm wide by 5 mm thick using a spacer. The resulting test piece was fired at 300 C. for 2 hours. Thus, the coating film was prepared. Coloring of the coating film was visually observed, and evaluated by the following criterion. Table 1 shows the results.

(4) OO Not colored

(5) O Slightly colored

(6) Colored in yellow ocher

(7) x Colored in brown

Examples 2 to 8 and Comparative Examples 1 to 5

(8) Powder coating materials were prepared by the same procedures as those in Example 1, except that the cobalt compounds shown in Table 1 were used in an amount shown in Table 1 or cobalt (elemental cobalt), copper oxide, copper acetate, or copper benzoate was added instead of the cobalt compound in an amount shown in Table 1. The powder coating materials were evaluated for heat resistance.

Comparative Example 6

(9) A copolymer powder having a melt flow rate of 26 g/10 min at 297 C. and having a molar ratio of ethylene:TFE:(perfluorobutyl)ethylene of 42.6:56.2:1.2 was made into a sheet using a roller compactor, and the sheet was crushed into granular materials, each having a size of about 2 mm. The materials were ground and classified using an atomizer grinding machine. Thus, a powder coating material having an average particle size of 220 m and a apparent density of 0.70 g/ml was prepared. No cobalt compound was added. Subsequently, the powder coating material was evaluated for heat resistance by the same procedures as those in Example 1.

(10) TABLE-US-00001 TABLE 1 Added substance Amount* Coloring Example 1 Cobalt acetate 0.001 Example 2 Cobalt acetate 0.005 Example 3 Cobalt benzoate 0.001 Example 4 Cobalt benzoate 0.005 Example 5 Phthalocyanine cobalt 0.0001 Example 6 Phthalocyanine cobalt 0.0005 Example 7 Phthalocyanine cobalt 0.001 Example 8 Phthalocyanine cobalt 0.005 Comparative Example 1 Cobalt 0.005 X (elemental cobalt) Comparative Example 2 Copper oxide 0.001 X Comparative Example 3 Copper oxide 0.005 Comparative Example 4 Copper acetate 0.005 Comparative Example 5 Copper benzoate 0.005 Comparative Example 6 None X *Parts by mass relative to 100 parts by mass of a copolymer comprising ethylene, TFE, and (perfluorobutyl)ethylene

(11) Table 1 shows that the coloring of the coating film in accordance with Comparative Example 6 in which no cobalt compound was added was observed. On the other hand, in the coating films in accordance with Examples 1 to 8 in which cobalt acetate, cobalt benzoate, or phthalocyanine cobalt was added as the cobalt compound in an amount of 0.005 parts by mass or less relative to 100 parts by mass of the fluorine-containing polymer, prevention of coloring was observed. Particularly, phthalocyanine cobalt is more effective even if the amount thereof is small. In the coating films in accordance with Comparative Examples 1 to 5 in which cobalt (elemental cobalt), copper oxide, copper acetate, or copper benzoate was used in an amount of 0.005 parts by mass or less relative to 100 parts by mass of the fluorine-containing polymer, sufficient coloring prevention effects were not observed.

(12) Each value in Examples 9 to 18 and Comparative Examples 7 to 11 was determined by the following methods.

(13) [MFR]

(14) Using a melt indexer (product of Toyo Seiki Seisaku-sho, Ltd.), the polymer was allowed to flow out through a nozzle with an inside diameter of 2 mm and a length of 8 mm for 10 minutes at 297 C. at a load of 5 kg according to ASTM D3159. The mass of the polymer was determined as the MFR.

(15) [Copolymer Composition]

(16) The amount of each monomer unit of the copolymer was determined by appropriately combining the techniques of NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis in accordance with the kind of the monomer.

(17) [Melting Point]

(18) The melting point was determined as the temperature corresponding to the maximum value on a heat-of-fusion curve recorded using a DSC apparatus (product of Seiko) at a rate of 10 C./min.

(19) [Thermal Decomposition Temperature]

(20) Using a thermogravimetry-differential thermal analysis apparatus (TG-DTA6200, product of SII NanoTechnology Inc.), a sample was heated at a rate of 10 C./min in air and the variations in weight of the sample was measured. The temperature required for the sample to lose 1% of the mass thereof was determined as the thermal decomposition temperature.

(21) [Heat Aging Test]

(22) The resin composition kneaded was segmented into small pieces. The small pieces were placed into a mold of 120, and the mold was mounted on a pressing machine set at 320 C. After 20-minute preheating, compression forming was performed at 4.7 MPaG for 1 minute to produce a 1.5 mm thick sheet. A dumbbell specimen was punched in the resulting sheet in accordance with ASTM D3159, placed in a hot air circulating electric furnace that was heated to 240 C., and allowed to stand for 300 hours. The specimen was then taken out from the furnace and cooled, and subjected to a tensile test at a tensile speed of 50.00 mm/min using a Tensilon universal testing machine (product of ORIENTEC). Average values of tensile strength and tensile elongation at in the case where number is 4 were determined and the remaining ratios were calculated from the values before heat aging.

Synthetic Example 1

(23) A 1000-L autoclave was charged with 416 L of distilled water, the atmosphere in the autoclave was sufficiently replaced with nitrogen gas, and then 287 kg of octafluorocyclobutane was added. Then, the temperature in the system was maintained at 35 C. and the rate of stirring was maintained at 130 rpm. Subsequently, 76.1 kg of tetrafluoroethylene, 2.4 kg of ethylene, 1.47 kg of (perfluorohexyl)ethylene, and 0.63 kg of cyclohexane were added thereto, and thereafter, 3.1 kg of di-n-propylperoxydicarbonate was added. Then, a polymerization reaction was initiated. The pressure in the system may be reduced with the progress of the polymerization. Therefore, mixed gas of tetrafluoroethylene/ethylene=57.0/43.0 mol % was continuously added to thereby maintain the pressure in the system at 1.20 MPaG. At the same time, 18.2 kg of (perfluorohexyl)ethylene in total was continuously added and the polymerization reaction was continued. After 2.5 hours from the start of the polymerization, 330 g of cyclohexane was added for MFR adjustment. After 17 hours from the start of the polymerization, the pressure in the system was released to atmospheric pressure, and the reaction product was rinsed with water and dried to give 250 kg of a fluororesin powder (fluororesin powder (1)). The rate of the polymerization in the first 2.5 hours of the polymerization was almost uniform, 17.2 kg/hr, and from this point, the rate of the polymerization was 16.0 kg/hr through the completion of the polymerization. The resulting fluororesin powder has a molar ratio of ethylene:tetrafluoroethylene:(perfluorohexyl)ethylene of 42.2:56.4:1.4, a melting point of 252 C., and an MFR of 4.7 (g/10 min).

Synthesis Example 2

(24) A 1000-L autoclave was charged with 312 L of distilled water, the atmosphere in the autoclave was sufficiently replaced with nitrogen gas, and then 212 kg of octafluorocyclobutane was added. Then, the temperature in the system was maintained at 35 C. and the rate of stirring was maintained at 130 rpm. Then, mixed gas of tetrafluoroethylene/ethylene=79/21 mol % was added to increase the pressure in the system to 1.28 MPaG. Further, 1.5 kg of perfluoro(1,1,5-trihydro-1-pentene) and 1.7 kg of cyclohexane were added thereto, and thereafter, 1.1 kg of di-n-propylperoxydicarbonate was added. Then, a polymerization reaction was initiated. The pressure in the system may be reduced with the progress of the polymerization. Therefore, mixed gas of tetrafluoroethylene/ethylene=56.0/44.0 mol % was continuously added to thereby maintain the pressure in the system at 1.28 MPaG. Further, 8.5 kg of perfluoro(1,1,5-trihydro-1-pentene) in total was continuously added, and the polymerization was continued. After 25 hours from the start of the polymerization, the pressure in the system was released to atmospheric pressure, and the reaction product was rinsed with water and dried to give 200 kg of a fluororesin powder (fluororesin powder (2)). The resulting fluororesin powder has a molar ratio of ethylene:tetrafluoroethylene:perfluoro(1,1,5-trihydro-1-pentene) of 43.5:55.0:1.5, a melting point of 264 C., and an MFR of 14.5 (g/10 min).

(25) [Melt Kneading]

(26) The amount of 66 g of a fluororesin including an additive with a predetermined concentration was added to a Labo Plastomill mixer (product of Toyo Seiki Co. Ltd) set at 290 C. The mixture was preliminarily kneaded at 10 rpm for 4 minutes, and then melt-kneaded at 70 rpm for 5 minutes. Thus, a resin composition was prepared.

Example 9

(27) Phthalocyanine cobalt (trade name: Chromofine Blue 5000P, product of Dainichiseika Colour & Chemicals Mfg. Co., Ltd.) was added to the fluororesin powder (1) in an amount of 50 ppm by mass of the total amount of the fluororesin powder (1) and phthalocyanine cobalt (in an amount of 0.0050 parts by mass relative to 100 parts by mass of the fluorine-containing polymer (1)). The fluororesin powder (1) and phthalocyanine cobalt were shook up in a plastic bag. The mixture was melt-kneaded by the above-mentioned procedures to prepare a resin composition. The resin composition was subjected to a heat-aging test by the above-mentioned procedures. Table 2 shows the results.

Example 10

(28) The resin composition was prepared by the same procedures as those in Example 9, except that as an additive to be added to the fluororesin powder (1), [5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphinato]cobalt (II) (abbreviation: TMP-Co) (trade name: meso-tetramethoxy phenyl porphin cobalt, product of Wako Pure Chemical Industries, Ltd.) was used, and TMP-Co was added in an amount of 50 ppm by mass of the total amount of the fluororesin powder (1) and TMP-Co. Then, the resin composition was subjected to a heat-aging test. Table 2 shows the results.

Example 11

(29) The resin composition was prepared by the same procedures as those in Example 9, except that as an additive to be added to the fluororesin powder (1), TMP-Co was added in an amount of 50 ppm by mass of the total amount of the fluororesin powder (1) and TMP-Co (in an amount of 0.0050 parts by mass relative to 100 parts by mass of the fluorine-containing polymer (1)). Then, the resin composition was subjected to a heat-aging test. Table 2 shows the results.

Example 12

(30) The resin composition was prepared by the same procedures as those in Example 9, except that as an additive to be added to the fluororesin powder (1), TMP-Co was added in an amount of 20 ppm by mass of the total amount of the fluororesin powder (1) and TMP-Co (in an amount of 0.0020 parts by mass relative to 100 parts by mass of the fluorine-containing polymer (1)). Then, the resin composition was subjected to a heat-aging test. Table 2 shows the results.

Comparative Example 7

(31) The fluororesin powder (1) was subjected to a heat-aging test by the above-mentioned procedures. Table 2 shows the results.

(32) TABLE-US-00002 TABLE 2 Concentration Tensile strength Tensile elongation Thermal decomposition Resin Additive of additive (retention rate/%) (retention rate/%) temperature ( C.) Example 9 Synthesis Phthalocyanine Co 50 ppm by mass 75 101 398.5 Example 1 Example 10 Synthesis TMP-Co 100 ppm by mass 72 89 424.3 Example 1 Example 11 Synthesis TMP-Co 50 ppm by mass 78 102 416.2 Example 1 Example 12 Synthesis TMP-Co 20 ppm by mass 73 99 401.5 Example 1 Comparative Synthesis None 54 80 366 Example 7 Example 1

Example 13

(33) The resin composition was prepared by the same procedures as those in Example 9, except that as an additive to be added to the fluororesin powder (1), titanium dioxide (abbreviation: TiO.sub.2) (trade name: D-918, product of Sakai Chemical Industry Co., Ltd.) was added in an amount of 1% by mass of the total amount of the fluororesin powder (1) and phthalocyanine cobalt, and phthalocyanine cobalt was added in an amount of 50 ppm by mass of the total amount of the fluororesin powder (1) and phthalocyanine cobalt (in an amount of 0.00500 parts by mass relative to 100 parts by mass of the fluorine-containing polymer (1)). Then, the resin composition was subjected to a heat-aging test. Table 3 shows the results.

Example 14

(34) The resin composition was prepared by the same procedures as those in Example 9, except that as an additive to be added to the fluororesin powder (1), TiO.sub.2 was added in an amount of 1% by mass of the total amount of the fluororesin powder (1) and TMP-Co, and TMP-Co was added in an amount of 50 ppm by mass of the total amount of the fluororesin powder (1) and TMP-Co (in an amount of 0.0050 parts by mass relative to 100 parts by mass of the fluorine-containing polymer (1)). Then, the resin composition was subjected to a heat-aging test. Table 3 shows the results.

Comparative Example 8

(35) The resin composition was prepared by the same procedures as those in Example 9, except that as an additive to be added to the fluororesin powder (1), TiO.sub.2 was added in an amount of 1% by mass of the total amount of the fluororesin powder (1) and TiO.sub.2, and no phthalocyanine cobalt was added. Then, the resin composition was subjected to a heat-aging test. Table 3 shows the results.

(36) TABLE-US-00003 TABLE 3 Original Concentration Tensile strength Tensile elongation Thermal decomposition resin Additive of additive (retention rate/%) (retention rate/%) temperature ( C.) Example 13 Synthesis TiO.sub.2 1% by mass 65 78 371.7 Example 1 Phthalocyanine Co 50 ppm by mass Example 14 Synthesis TiO.sub.2 1% by mass 82 106 388.4 Example 1 TMP-Co 50 ppm by mass Comparative Synthesis TiO.sub.2 1% by mass 58 66 366.4 Example 8 Example 1

Example 15

(37) The resin composition was prepared as follows: TMP-Co was added to the fluororesin powder (2) in an amount of 50 ppm by mass of the total amount of the fluororesin powder (2) and TMP-Co (in an amount of 0.0050 parts by mass relative to 100 parts by mass of the fluorine-containing polymer (2)). The mixture was melt-kneaded by the same procedures as those in Example 9. The thermal decomposition temperature of the resin composition was measured by the above-mentioned procedures. Table 4 shows the results.

Example 16

(38) The resin composition was prepared as follows: TMP-Co was added to FEP (trade name: Neoflon FEP NP101, product of DAIKIN INDUSTRIES, Ltd.) in an amount of 50 ppm by mass of the total amount of FEP and TMP-Co (in an amount of 0.0050 parts by mass relative to 100 parts by mass of FEP). The mixture was melt-kneaded by the same procedures as those in Example 9. The thermal decomposition temperature of the resin composition was measured by the above-mentioned procedures. Table 4 shows the results.

Example 17

(39) The resin composition was prepared as follows: TMP-Co was added to PVdF (trade name: Neoflon PVDF VP825, product of DAIKIN INDUSTRIES, Ltd.) in an amount of 50 ppm by mass of the total amount of PVdF and TMP-Co (in an amount of 0.0050 parts by mass relative to 100 parts by mass of PVdF). The mixture was melt-kneaded at 210 C. using a laboratory mill. The thermal decomposition temperature of the resin composition was measured by the same procedures as those in Example 13. Table 4 shows the results.

Comparative Example 9

(40) The thermal decomposition temperature of the fluororesin powder (2) was measured by the above-mentioned procedures. Table 4 shows the results.

Comparative Example 10

(41) The thermal decomposition temperature of the FEP (trade name: Neoflon FEP NP101, product of DAIKIN INDUSTRIES, Ltd.) was measured by the above-mentioned procedures. Table 4 shows the results.

Comparative Example 11

(42) The thermal decomposition temperature of the PVdF (trade name: Neoflon PVDF VP825, product of DAIKIN INDUSTRIES, Ltd.) was measured by the above-mentioned procedures. Table 4 shows the results.

(43) TABLE-US-00004 TABLE 4 Thermal decomposition Original Concentration of temperature/ resin Additive additive C. Example 15 Synthesis TMP-Co 50 ppm by mass 402.5 Example 2 Example 16 FEP TMP-Co 50 ppm by mass 410.7 Example 17 PVdF TMP-Co 50 ppm by mass 398.2 Comparative Synthesis None 352.6 Example 9 Example 2 Comparative FEP None 402.6 Example 10 Comparative PVdF None 375.6 Example 11

Example 18

(44) Cobalt(II) acetylacetonate dihydrate (product of Wako Pure Chemical Industries, Ltd.) was added to the fluororesin powder (1) in an amount of 50 ppm by mass of the total amount of the fluororesin powder (1) and cobalt(II) acetylacetonate dihydrate (in an amount of 0.0050 parts by mass relative to 100 parts by mass of the fluororesin powder (1)). The fluororesin powder (1) and cobalt(II) acetylacetonate dihydrate were shook up in a plastic bag. The mixture was melt-kneaded by the above-mentioned procedures to prepare a resin composition. The resin composition was subjected to a heat-aging test by the above-mentioned procedures. Table 5 shows the results of Example 18 and Comparative Example 7.

(45) TABLE-US-00005 TABLE 5 Concentration Tensile strength Tensile elongation Thermal decomposition Resin Additive of additive (Retention rate/%) (Retention rate/%) temperature ( C.) Example 18 Synthesis Cocobalt 50 ppm by mass 78 102 406.6 Example 1 acetylacetonate dihydrate Comparative Synthesis None 54 80 366 Example 7 Example 1

INDUSTRIAL APPLICABILITY

(46) The composition of the present invention can be used for various uses requiring heat resistance. Specifically, the composition is particularly useful as a powder coating material used in a corrosion resistant lining used for covering materials of electric wires, chemical and medical instruments, and semiconductor manufacturing facilities.

(47) The present application claims priority to Patent Application No. 2009-156023 filed in Japan on Jun. 30, 2009 and Patent Application No. 2010-084072 filed in Japan on Mar. 31, 2010 under the Paris Convention and provisions of national law in a designated State, the entire contents of which are hereby incorporated by reference.