JP2010126599A - Polycarbonate resin composition and molded product made of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin composition having high flame retardancy and less bad appearance because of the reduction of contaminants called black points. <P>SOLUTION: This polycarbonate resin composition includes: 100 pts.wt. of a polycarbonate resin (A); and 0.005-1 pt.wt. of a metal salt of perfluoroalkanesulfonic acid (B), as essential component, wherein iron contents in the metal salt of perfluoroalkanesulfonic acid (B) are ≤60 ppm. A molded product made of the resin composition is also disclosed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polycarbonate resin composition. More specifically, the polycarbonate resin is excellent in flame retardancy and contains few foreign matters by blending a metal salt of perfluoroalkanesulfonic acid with a polycarbonate resin, and optionally other flame retardants and / or fiber-forming fluorine-containing polymers. The present invention relates to a composition and a molded article comprising the composition.

  Polycarbonate resin is a thermoplastic resin excellent in impact resistance, heat resistance, thermal stability, and the like, and is widely used in fields such as electricity, electronics, ITE, machinery, and automobiles. Polycarbonate resin is a highly flame-retardant plastic material with self-extinguishing properties. However, in the above-mentioned fields, there is a strong demand for flame retardancy, and underwriters laboratories In the flame retardancy evaluation based on the established UL94 test (flammability test of plastic materials for equipment parts), higher flame retardancy equivalent to UL94V-0 and V-1 is required.

  As a method for imparting flame retardancy to a polycarbonate resin, a method of adding potassium perfluoroalkanesulfonate (Patent Document 1) has been proposed.

Japanese Patent Publication No. 47-40445

  However, although the flame retardancy of the polycarbonate resin is improved by the incorporation of potassium perfluoroalkanesulfonate, there is a problem that foreign matters called black spots are generated in the obtained molded product, and a solution has been desired.

  As a result of intensive studies in view of such problems, the present inventors have found that there is a correlation between the iron content in the metal salt of perfluoroalkanesulfonic acid and the occurrence of the sunspots, thereby completing the present invention. It came to do.

  That is, the first aspect of the present invention is a composition comprising 100 parts by weight of a polycarbonate resin (A) and 0.005 to 1 part by weight of a metal salt of perfluoroalkanesulfonic acid (B) as essential components. In addition, the present invention provides a polycarbonate resin composition characterized in that the iron contained in the metal salt (B) of perfluoroalkanesulfonic acid is 60 ppm or less, and a molded product comprising the same.

  The second aspect of the present invention is a polycarbonate resin composition obtained by further blending a flame retardant and / or a fiber-forming fluorine-containing polymer with a specific amount into the polycarbonate resin composition, and a molded article comprising the polycarbonate resin composition. It is to provide.

  Since the polycarbonate resin composition of the present invention has high flame retardancy and foreign substances called black spots are reduced, it is possible to obtain a molded product with few appearance defects.

  The polycarbonate resin (A) used in the present invention is a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method obtained by reacting a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate. A typical example is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone Sulfone, and the like.

  These may be used alone or in combination of two or more. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be used in combination.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination.

Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4′-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin (A) is usually 10,000 to 100,000, preferably 15,000 to 35,000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

  Examples of the metal salt (B) of perfluoroalkanesulfonic acid used in the present invention include a metal salt of perfluorobutanesulfonic acid, a metal salt of perfluorobutanedisulfonic acid, and the like. Examples of the metal include alkali metals and alkaline earth metals. In particular, a potassium salt of perfluorobutanesulfonic acid can be preferably used.

  In this invention, it is required that the iron content in the metal salt (B) of perfluoroalkanesulfonic acid is 60 ppm or less. If the iron content exceeds 60 ppm, foreign matter called black spots increase in the obtained molded product, which is not preferable because it causes poor appearance. Furthermore, the iron content is preferably 40 ppm or less.

  As a method for reducing the iron content of the metal salt (B) of perfluoroalkanesulfonic acid to 60 ppm or less, a raw material for introducing the metal salt (B) into an extruder used for producing a polycarbonate resin composition There is a method in which a metal separator is installed in the vicinity of the outlet of the supply feeder or in a supply line to the extruder and the iron in the metal salt (B) is removed. The magnetic force of the metal separator is preferably 5000 gauss or more, more preferably 9000 gauss or more.

  As another method, the metal salt (B) of perfluoroalkanesulfonic acid is removed from the iron using a belt-type, drum-type or rotary-type metal separator, and then charged into the raw material supply feeder of the extruder. It is also possible to do.

  As a method for measuring the iron content in the metal salt (B) of perfluoroalkanesulfonic acid, iron having a known concentration is dissolved in concentrated hydrochloric acid, pure water, an acetate / ammonia solution and a Ferrozine reagent are added, and the solution is added. Then, wavelength measurement is performed using an ultraviolet / visible spectrophotometer, an absorption value of 566 nm with respect to the iron concentration is obtained, and a calibration curve is created. Next, the metal salt (B) of perfluoroalkanesulfonic acid is dissolved in pure water, concentrated hydrochloric acid, acetate / ammonia solution and Ferrozine reagent are added, and the solution is subjected to wavelength measurement using an ultraviolet / visible spectrophotometer. It is obtained by comparing the obtained absorption value with a calibration curve.

  The compounding quantity of the metal salt (B) of perfluoroalkanesulfonic acid is 0.005-1 weight part with respect to 100 weight part of polycarbonate resin (A). If it is less than 0.005 parts by weight, the flame retardancy is lowered, which is not preferable. On the other hand, when the amount exceeds 1 part by weight, the thermal stability is inferior, and appearance defects such as silver streak occur at the time of injection molding. Preferably it is 0.02-0.5 weight part, More preferably, it is 0.04-0.2 weight part.

The silicone-based flame retardant (C-1) used in the present invention has a main chain having a branched structure and an organic functional group comprising an aromatic group, or an aromatic group and a hydrocarbon group (excluding an aromatic group). And is represented by the following general formula (1).
General formula (1)

Here, R1, R2, and R3 represent main chain organic functional groups, and X represents a terminal functional group.
That is, it has a T unit (RSiO1.5) and / or a Q unit (SiO2.0) as a branch unit. These are preferably contained in an amount of 20 mol% or more of the entire siloxane units (R3 to 0SiO2 to 0.5). (R represents an organic functional group.) Further, the silicone compound (C) preferably contains 20 mol% or more of aromatic groups among the organic functional groups contained.

  The aromatic group contained is phenyl, biphenyl, naphthalene or a derivative thereof, but a phenyl group can be preferably used.

  Of the organic functional groups in the silicone-based flame retardant (C-1) and attached to the main chain or branched side chain, the organic group other than the aromatic group is preferably a hydrocarbon group having 4 or less carbon atoms. A group can be suitably used. Further, the terminal group is preferably one kind selected from methyl group, phenyl group and hydroxyl group, or a mixture of these two kinds to three kinds.

  The average molecular weight (weight average) of the silicone flame retardant (C-1) is preferably 3,000 to 500,000, more preferably 5,000 to 270000. If it is less than 3000, the heat resistance of the silicone-based flame retardant (C-1) itself is lowered and a sufficient flame-retardant effect cannot be obtained, and the melt viscosity is too low so that the silicone-based flame retardant (C -1) may bleed out and impair the appearance. On the other hand, if it exceeds 500,000, the melt viscosity increases and uniform dispersion in the polycarbonate resin cannot be achieved, and the flame retardancy and moldability are lowered. . More preferably, it is 10,000 to 270000. In this range, since the melt viscosity is optimum, better flame retardancy and formability can be achieved.

  The compounding quantity of a silicone type flame retardant (C-1) is 5 weight part or less per 100 weight part of polycarbonate resin (A). If the blending amount exceeds 5 parts by weight, a sufficient flame retardant effect cannot be obtained, which is not preferable. More preferably, it is the range of 0.1-3 weight part.

  As the phosphorus flame retardant (C-2) or bromine flame retardant (C-3) used in the present invention, oligomer type condensation such as bisphenol A diphosphate, resorcin diphosphate, tetraxylenyl resorcin diphosphate, etc. Examples include brominated flame retardants such as phosphate ester flame retardants and tetrabromobisphenol A oligomers.

  In addition to these flame retardants, monophosphate esters such as triphenyl phosphate and tricresyl phosphate, and phosphorus-based flame retardants such as ammonium polyphosphate and red phosphorus may be used in combination with other flame retardants as required. Can be added.

  The compounding amount of the phosphorus flame retardant (C-2) or bromine flame retardant (C-3) is 20 parts by weight or less per 100 parts by weight of the polycarbonate resin (A). If the blending amount exceeds 20 parts by weight, it is not preferable because extreme heat resistance and impact strength are reduced. More preferably, it is the range of 2-15 weight part.

  As the fiber-forming fluorine-containing polymer (D) used in the present invention, those that form a fiber structure (fibril structure) in the polycarbonate resin (A) are preferable. Polytetrafluoroethylene, tetrafluoroethylene Examples thereof include a system copolymer (for example, tetrafluoroethylene / hexafluoropropylene copolymer, etc.), a partially fluorinated polymer as shown in US Pat. No. 4,379,910, a polycarbonate produced from a fluorinated diphenol, and the like. In particular, polytetrafluoroethylene having a molecular weight of 1,000,000 or more and a fibril-forming ability having a secondary particle diameter of 100 μm or more is preferably used.

  The blending amount of the fiber-forming fluoropolymer (D) is 3 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin (A). If the blending amount exceeds 3 parts by weight, granulation becomes difficult, which hinders stable production. Furthermore, appearance defects such as silver streaks occur during injection molding, which is not preferable. This blending amount is preferably in the range of 0.1 to 2 parts by weight, more preferably 0.3 to 1 part by weight.

  Various blending components (A), (B) of the present invention, and (C-1), (C-2), (C-3), (D) blending method and melt kneading method are not particularly limited depending on necessity. Alternatively, these can be mixed with an optional mixer such as a tumbler, ribbon blender, high-speed mixer, etc., and melt kneaded with a normal single or twin screw extruder. Moreover, there is no restriction | limiting in particular also about the mixing | blending order of these compounding components, collective mixing, and division | segmentation mixing.

  In addition, other known additives such as mold release agents, ultraviolet absorbers, fillers, antistatic agents, antioxidants, phosphorous heat stabilizers, dyes and pigments, spreading agents (epoxies) may be used as necessary. Modified soybean oil, liquid paraffin, and the like).

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Parts and% are based on weight unless otherwise specified.

The details of the used blending components are as follows.
Linear polycarbonate resin:
Caliber 200-20 (viscosity average molecular weight: 19000) manufactured by Sumitomo Dow
(Hereinafter abbreviated as PC-1)
Branched polycarbonate resin:
Caliber 600-3 (viscosity average molecular weight: 24000) manufactured by Dow Chemical
(Hereafter abbreviated as PC-2)

Metal salt of perfluoroalkanesulfonic acid:
1 g of potassium perfluorobutanesulfonate (trade name: PPBS, hereinafter abbreviated as metal salt-A) manufactured by MPI is dissolved in 5 ml of 3N hydrochloric acid, and 5 ml, 4 ml of pure water, ammonia / acetate solution and Ferrozine reagent are respectively obtained. 1 ml was added, and an absorption wavelength of 566 nm was measured using an ultraviolet / visible spectrophotometer (UV-2200A manufactured by Shimadzu Corporation). The iron content was determined from a comparison between the absorption wavelength of 566 nm and a calibration curve prepared at a known concentration. As a result, the iron content in metal salt-A was 167 ppm.

Next, 100 g of metal salt-A was put into a metal separator manufactured by Nippon Elise Magnetic Co., Ltd. to remove the iron component. When the iron content was measured based on the above-described method for measuring the iron content, it was 24 ppm (hereinafter abbreviated as metal salt-B).

Moreover, metal salt-A and metal salt-B were dry-mixed by arbitrary ratios, and metal salt-C-F which changed iron content was created. It was as follows when the iron content of these metal salts was measured according to the said measuring method.
Metal salt-C: 90 ppm
Metal salt-D: 59 ppm
Metal salt-E: 40 ppm
Metal salt-F: 30 ppm

Silicone flame retardant (hereinafter abbreviated as C-1):
The silicone flame retardant was produced according to a general production method. That is, a silicone compound partially condensed by dissolving an appropriate amount of diorganodichlorosilane, monoorganotrichlorosilane and tetrachlorosilane, or a partially hydrolyzed condensate thereof in an organic solvent, adding water and hydrolyzing. Then, triorganochlorosilane was added and reacted to terminate the polymerization, and then the solvent was separated by distillation or the like. The structural characteristics of the silicone flame retardant synthesized by the above method are as follows:
・ D / T / Q unit ratio of main chain structure: 40/60/0 (molar ratio)
-Ratio of phenyl group in all organic functional groups (*): 60 mol%
-Terminal group: methyl group only-Weight average molecular weight (**): 15000
*: The phenyl group is first contained in the T unit in the silicone containing the T unit, and the remaining D group is contained in the D unit. When the phenyl group is attached to the D unit, the one attached is preferential, and when the phenyl group remains, two are attached. Except for the terminal group, the organic functional group is a methyl group except for the phenyl group.
**: Weight average molecular weight is two significant digits.

Phosphorus flame retardant (hereinafter abbreviated as C-2):
PX-200 made by Daihachi Chemical Co., Ltd.
(Tetraxylenyl resorcin diphosphate)
Brominated flame retardant (hereinafter abbreviated as C-3):
Great Lakes BC-52
(Tetrabromobisphenol A oligomer)

Fiber-forming fluorine-containing polymer (hereinafter abbreviated as PTFE):
Daikin polyflon FA500
(Polytetrafluoroethylene)

(Evaluation of sunspot foreign matter)
The pellets of various resin compositions obtained based on the blending components and blending ratios shown in Tables 2 to 4 were each dried at 125 ° C. for 4 hours, and then set using an injection molding machine (Nippon Steel Works J-100SAII). An appearance evaluation test piece (90 × 50 × 3.0 mm) was prepared at a temperature of 300 ° C. The number of black spot foreign matter in the obtained test piece was visually counted with a foreign matter inspection machine (model SKK-CL manufactured by Otsuka Manufacturing). The number of black spot foreign matters was an average value of five test pieces for appearance evaluation (the decimal point was rounded off), black spot foreign substances were evaluated according to the following criteria, and ◯ and Δ were acceptable. The results are shown in Tables 2-4.
Average number of sunspots: 10 or less (○)
Average number of black spots: 11 to 15 (△)
Average number of black spots: 16 points or more (×)

(Appearance evaluation of molded products)
The appearance of the test piece for appearance evaluation obtained by the above method was visually observed, the appearance was determined based on the following criteria, and “◯” was accepted. The results are shown in Tables 2-4.
Good appearance (◯): Silver streak does not occur and a uniform appearance is obtained.
Appearance defect (x): Silver streak occurs and an unfavorable appearance is obtained.

(Flame retardance evaluation)
After the pellets of the various resin compositions obtained were dried at 125 ° C. for 4 hours, a test piece for flame retardancy evaluation (125 × 13 × 3.3) at a set temperature of 280 ° C. using an injection molding machine (J-100SAII manufactured by Nippon Steel) 0 mm). The obtained specimen is left in a constant temperature room at 23 ° C. and 50% humidity for 72 hours, and is subjected to UL94 test (flammability test of plastic materials for equipment parts) defined by Underwriters Laboratories. The compliant flame retardancy was evaluated, and V-0 or V-1 was determined to be acceptable. The results are shown in Tables 2-4. The flame resistance class of UL94 is as shown in Table 1.

The after flame time is the length of time that the test piece after the ignition source is moved away from the flame, and the ignition of the cotton by the drip is for the sign about 300 mm below the lower end of the test piece. Of cotton is ignited by a drip from the specimen.

  In the case where the resin composition satisfies the constituent requirements of the present invention (Examples 1 to 16), good results were exhibited over all the evaluation items.

On the other hand, in the case where the resin composition does not satisfy the constituent requirements of the present invention, each case had some drawbacks.
Comparative Examples 1, 2, 5 and 6 were cases where the iron content of the metal salt (B) was larger than the range defined by the present invention, and was inferior to the average number of sunspot foreign substances.
Comparative Example 3 was a case where the blending ratio of the metal salt (B) was less than the range defined by the present invention, and was inferior in flame retardancy.
Comparative Example 4 was a case where the blending ratio of the metal salt (B) was larger than the range defined by the present invention, and the appearance of the molded product was inferior.
Comparative Example 7 was a case where the blending amount of the silicone flame retardant was larger than the range of the present invention, and the appearance was inferior.
The comparative example 8 is a case where the compounding quantity of a phosphorus flame retardant is more than the range of this invention, and was inferior to the molded article external appearance.
Comparative Example 9 is a case where the blending ratio of the brominated flame retardant is larger than the range defined by the present invention, and the appearance of the molded product was inferior.
Comparative Example 10 was a case where the blending ratio of PTFE was larger than the range defined by the present invention, and the appearance of the molded product was inferior.

Claims (7)

  A composition comprising 100 parts by weight of a polycarbonate resin (A) and a metal salt of perfluoroalkanesulfonic acid (B) 0.005 to 1 part by weight as essential components, the metal salt of perfluoroalkanesulfonic acid (B) Iron contained in 60 ppm or less, The polycarbonate resin composition characterized by the above-mentioned.   The polycarbonate resin composition according to claim 1, wherein the iron contained in the metal salt (B) of perfluoroalkanesulfonic acid is 40 ppm or less.   The polycarbonate resin composition according to claim 1 or 2, wherein the metal salt (B) of perfluoroalkanesulfonic acid is potassium perfluorobutanesulfonate.   The polycarbonate resin composition according to claim 1 or 2, further comprising 5 parts by weight or less of the silicone-based flame retardant (C-1) (per 100 parts by weight of the polycarbonate resin (A)). Resin composition.   The polycarbonate resin composition according to claim 1 or 2, further containing 20 parts by weight or less of a phosphorus-based flame retardant (C-2) or a brominated flame retardant (C-3) (per 100 parts by weight of the polycarbonate resin (A)) A polycarbonate resin composition comprising:   The polycarbonate resin composition according to any one of claims 1 to 5, further comprising 3 parts by weight or less of a fiber-forming fluoropolymer (D) (per 100 parts by weight of the polycarbonate resin (A)). A polycarbonate resin composition.   The molded article formed by shape | molding the polycarbonate resin composition as described in any one of Claims 1-6.