JP6215717B2 - Antistatic polycarbonate resin composition - Google Patents

Description

  The present invention relates to an antistatic polycarbonate resin composition excellent in thermal stability and transparency. More specifically, the present invention relates to an antistatic polycarbonate resin composition that suppresses generation of gas during molding by an antistatic agent and is excellent in transparency.

  Polycarbonate resins are excellent in impact resistance, heat resistance, and transparency, and are widely used in fields such as electrical / electronic, optical, building materials, medical, food, and vehicles. However, products obtained from polycarbonate resin are easily charged with static electricity, and there are problems associated with static electricity, such as adhesion of dust to packaging materials and molded products, electric shock during molding and use, and malfunction of OA machines. Conventionally, various formulations of antistatic agents have been studied. Further, office equipment exterior parts such as optical disk cartridges are also required to have transparency so that the inside can be fully visually recognized simultaneously with the antistatic performance.

In order to impart antistatic performance to the polycarbonate resin, a phosphonium salt is blended as an antistatic agent. (Patent Document 1) However, this composition cannot sufficiently satisfy antistatic properties, transparency, and thermal stability.
In addition, a diglycerin fatty acid ester and an antioxidant are blended in a polycarbonate resin. (Patent Document 2) Although this composition is improved in antistatic performance and transparency to some extent, it has a problem that a diglycerin fatty acid ester is decomposed and gas is generated during molding.

JP 2005-272678 A JP-A-2-196852

  The present invention relates to an antistatic polycarbonate which has improved heat stability by using an ester compound comprising a specific polyhydric alcohol and a fatty acid as an antistatic agent, prevents a large amount of gas generation, and has excellent transparency. It aims at providing a resin composition.

  As a result of earnest research on the above-mentioned problems, the present inventor has improved thermal stability by blending a polycarbonate resin with an ester compound composed of a specific polyhydric alcohol and a fatty acid and an epoxy polymer containing a glycidyl group. As a result, the inventors have found that an antistatic polycarbonate resin composition that can remarkably prevent the generation of a large amount of gas and that is excellent in transparency can be obtained, thereby completing the present invention.

  That is, the present invention relates to (A) 100 parts by weight of a polycarbonate resin (component A), (B) 0.5 to 5 parts by weight of an ester compound (component B) composed of a polyhydric alcohol and a fatty acid, and (C) a glycidyl group. An epoxy polymer (component C) containing 0.003 to 0.5 parts by weight, and the molar ratio (hydroxy group / carboxyl group) of the hydroxy group of the polyhydric alcohol and the carboxyl group of the fatty acid in the B component is 4 An antistatic polycarbonate resin composition characterized by being in the range of ˜8, and a molded article comprising the same.

  The antistatic polycarbonate resin composition of the present invention is excellent not only in antistatic properties but also in thermal stability and transparency, and can be used for applications that are transparent and avoid the adhesion of dust, such as light source peripheral members and contents. It is suitably used for molded products.

Hereinafter, the present invention will be described in detail.
<About component A>
The polycarbonate resin used as the component A of the present invention is a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method obtained by a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example is an aromatic 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 are used individually or in mixture of 2 or more types. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be mixed and used.

  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 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.

<About B component>
The molar ratio (hydroxy group / carboxyl group) of the hydroxy group of the polyhydric alcohol and the carboxyl group of the fatty acid is 4 to 8 in the ester compound composed of the polyhydric alcohol and the fatty acid used as the B component of the present invention. The range is preferably 4-6, more preferably 4-5. When the molar ratio is less than 4, the antistatic property is inferior. When it exceeds 8, the thermal stability is deteriorated and a large amount of gas is generated.

  As polyhydric alcohol components, diglycerin, triglycerin, tetraglycerin, pentaglycerin, hexaglycerin, pentaerythritol, inositol, ribulose, xylulose, ribose, arabinose, xylose, lyxose, psicose, fructose, sorbose, tagatose, allose, Examples thereof include altrose, glucose, mannose, gulose, idose, galactose, talose, fucose, fucose, rhamnose, sedheptulose, sucrose, lactose, maltose, trehalose, tyranose, and cellobiose, among which diglycerin is preferably used.

  As the fatty acid, a fatty acid having 10 to 18 carbon atoms is preferably used. If the carbon number is less than 10, the sustainability of the antistatic performance may be inferior, and if the carbon number exceeds 18, the antistatic property may be inferior. Examples of the fatty acid having 10 to 18 carbon atoms include capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, and stearic acid.

  Specific examples of the ester compound comprising a polyhydric alcohol and a fatty acid include diglycerol monolaurate, diglycerol monomyristate, diglycerol monostearate, triglycerol monolaurate, triglycerol monomystate, triglycerol monostearate. Rate, tetraglycerol monolaurate, tetraglycerol monomyristate, tetraglycerol monostearate, pentaglycerol monolaurate, pentaglycerol monomyristate, pentaglycerol monostearate, hexaglycerol monolaurate, hexaglycerol monomyristate, Hexaglycerin monostearate, sucrose laurate, sucrose myristic ester, sucrose palmitate, sucrose stearate, etc. Is, preferably diglycerol monolaurate is used.

  Content of B component is 0.5-5 weight part with respect to 100 weight part of A component. Preferably it is 0.7-3 weight part, More preferably, it is 1-2 weight part. When the content is less than 0.5 parts by weight, the antistatic property is inferior.

<About component C>
The epoxy polymer containing a glycidyl group used as component C of the present invention is preferably an epoxy polymer containing glycidyl methacrylate in the copolymer, and polystyrene is suitably used as the other component of the copolymer. . When an epoxy polymer not containing a glycidyl group is used, the compatibility with the component A is poor and the transparency is poor.

  As the monomer component of the polymer containing a glycidyl group, allyl glycidyl ether, glycidyl methacrylate, glycidyl acrylate, 4-hydroxybutyl acrylate glycidyl ether, 1,2-epoxy-5-hexene, 1,2-epoxy-9-decene, Examples thereof include epoxy succinic acid, and examples of the polymer include terminal epoxy-modified polydimethylsiloxane and side chain epoxy-modified polydimethylsiloxane. Among these, a polyglycidyl methacrylate-polystyrene copolymer is preferably used.

  Content of C component is 0.003-0.5 weight part with respect to 100 weight part of A component, Preferably it is 0.01-0.1 weight part, More preferably, it is 0.03-0.05 weight. Part. If the content is less than 0.003 parts by weight, the thermal stability is inferior and decomposition gas is generated. If it exceeds 0.5 parts by weight, decomposition gas is generated from the epoxy polymer itself, which is not preferable.

<About D component>
The resin composition of the present invention can contain a phosphorus-based antioxidant as the D component. Examples of the phosphorus-based antioxidant include at least one compound selected from the group consisting of phosphite-based antioxidants represented by the following general formulas (1) to (3).

  In General formula (1), R1-R4 shows a C1-C20 alkyl group or an aryl group. R1 to R4 may be the same or different. Preferable examples of R1 to R4 include 2,4-di-tert-butylphenyl.

  In General formula (2), R5 and R6 represent a C1-C20 alkyl group or an aryl group. R5 and R6 may be the same or different. Preferable examples of R5 and R6 include 2,4-di-tert-butylphenyl.

  In General formula (3), Ar shows the aryl group which may be substituted by a C1-C20 alkyl group. Ar may be the same or different. Preferable examples of the substituent represented by Ar include 2,4-di-tert-butylphenyl.

  The content of the component D is preferably 0.005 to 1 part by weight, more preferably 0.01 to 0.5 part by weight, and still more preferably 0.02 to 0. 1 part by weight. If the content is less than 0.005 parts by weight, the thermal stability may be inferior, and if it exceeds 1 part by weight, the hue may deteriorate, which is not preferable.

<Other ingredients>
The antistatic polycarbonate resin composition of the present invention can be used in combination with other antistatic agents as long as the effects of the present invention are not impaired. As other antistatic agents that can be used in combination, widely known ones can be used, and examples thereof include alkylsulfonates, alkylbenzenesulfonates, ammonium salts, and other phosphonium salts. It is not limited to. Furthermore, known additives such as heat stabilizers, mold release agents, ultraviolet absorbers, flame retardants, flame retardant aids, diffusing agents, fluorescent whitening agents, as long as the effects of the present invention are not impaired as required. In addition, additives such as dyes and pigments may be blended.

<Manufacture of resin composition>
In the resin composition of the present invention, A component, B component, C component and optionally other components are mixed simultaneously or in any order in a tumbler, V-type blender, nauter mixer, Banbury mixer, kneading roll, extruder, etc. It can be produced by mixing with a machine. Preferably, melt kneading with a twin-screw extruder is preferred, and if necessary, it is preferable to supply an optional component into the other melt-mixed component from the second supply port using a side feeder or the like.

<About molded products>
A molded product using the resin composition of the present invention can be obtained by molding the pellets produced as described above. Preferably, it is obtained by injection molding or extrusion molding. In injection molding, not only ordinary molding methods, but also injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including the method of injecting supercritical fluid), insert molding, in-mold coating molding, and heat insulation gold Examples thereof include mold molding, rapid heating / cooling mold molding, two-color molding, multicolor molding, sandwich molding, and ultrahigh-speed injection molding. In addition, either a cold runner method or a hot runner method can be selected for molding. In extrusion molding, various shaped extrusion molded products, sheets, films and the like are obtained. For forming sheets and films, an inflation method, a calendar method, a casting method, or the like can be used. It is also possible to form a heat-shrinkable tube by applying a specific stretching operation. The resin composition of the present invention can also be formed into a molded product by rotational molding, blow molding or 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” are based on weight unless otherwise specified.
Based on the blending components and blending amounts shown in Table 1, various blending components were mixed using a tumbler and melt kneaded at a cylinder temperature of 270 ° C. using a twin screw extruder (TEX-30α manufactured by Nippon Steel) Pellets were obtained.

In addition, the compounding component used is as follows, respectively.
1. A component PC: Panlite L-1225WP manufactured by Teijin Ltd. (viscosity average molecular weight: 22400)
2. B component B-1: Diglycerin monolaurate (molar ratio of hydroxy group of polyhydric alcohol to carboxyl group of fatty acid (hydroxy group / carboxyl group) is 4) (Poem DL-100 manufactured by Riken Vitamin Co., Ltd.)
B-2: Sucrose fatty acid ester (molar ratio of hydroxy group of polyhydric alcohol and carboxyl group of fatty acid (hydroxy group / carboxyl group) is 8) (Daiichi Kogyo Co., Ltd. DK Ester SS)
B-3: Glycerol monostearate (molar ratio of hydroxy group of polyhydric alcohol to carboxyl group of fatty acid (hydroxy group / carboxyl group) is 3) (Riken Vitamin Rikemar S-100A)
B-4: Decaglycerin lauric acid ester (molar ratio of hydroxy group of polyhydric alcohol to carboxyl group of fatty acid (hydroxy group / carboxyl group) is about 10) (Mitsubishi Chemical Foods Corporation Ryoto Polyglyceride L-10D)
3. Component C-1: Polyglycidyl methacrylate-polystyrene block copolymer (Mafproof G0250SP manufactured by NOF Corporation)
C-2: Side chain epoxy-modified polydimethylsiloxane (KF-1001 manufactured by Shin-Etsu Chemical Co., Ltd.)
C-3: Alicyclic epoxy polymer (Epoxy compound EHPE3150 manufactured by Daicel Corporation)
4). D component D-1: Phosphite antioxidant (P-EPQ manufactured by ADEKA)
Next, by using an injection molding machine (Toshiba Machine IS-150EN) using the obtained pellets, various test pieces were prepared at a cylinder setting temperature of 320 ° C and a mold temperature of 80 ° C. Carried out.

1. Antistatic property A flat plate of 90 mm × 50 mm × 2 mm was prepared by injection molding and measured under the following conditions. After the plate test piece was conditioned for 24 hours or more at 23 ° C. and 50% relative humidity, the surface resistivity was measured using a superinsulator (Digital Super Insulation DSM-8104 manufactured by Hioki Electric Co., Ltd.) at a measurement voltage of 100V. Was measured. A surface resistivity of 1 × 10 ¹⁴ Ω / □ or less was accepted.

2. Thermal stability When a 90 mm × 50 mm × 2 mm flat plate was formed by injection molding, it was retained for 10 minutes in a cylinder at a set temperature of 320 ° C. The hues of the molded product during stay molding and the molded product during normal molding were measured according to ASTM D-1925. The difference between the molded product during the stay molding and the molded product during normal molding was ΔE, and 2 or less was accepted. ΔE is defined by the following equation.
ΔE = {(ΔL) ² + (Δa) ² + (Δb) ² } ^1/2
Hue of “flat plate obtained from normal molding”: L, a, b
Hue of “flat plate obtained from stay forming”: L ′, a ′, b ′
ΔL: LL ′
Δa: aa ′
Δb: bb ′

3. Gas generation When forming a 90mm x 50mm x 2mm flat plate by injection molding, visually confirm the generation of gas from the purge ball after purging for 10 minutes in a cylinder with a set temperature of 320 ° C. did. If the generated gas became invisible within 5 shots after the start of the purging operation, the test was accepted.

4). Transparency A 90 mm × 50 mm × 2 mm flat plate was prepared by injection molding and measured by the following method. Using a Haze Meter HR-100 manufactured by Murakami Color Research Laboratory Co., Ltd., the total light transmittance in the thickness direction of the flat plate was measured according to JIS-K 7136. A total light transmittance of 87% or more was accepted.
The test results are shown in Table 1.

As shown in Examples 1 to 8, the polycarbonate resin composition having the requirements of the present invention is
All the required performance including the surface resistivity satisfies the required level.
On the other hand, in the case where the requirements of the present invention were not satisfied, each case had some drawbacks. In Comparative Example 1, the amount of the antistatic agent was small, and the surface resistance did not satisfy the required level. Comparative Example 2 was a case where the blending amount of the antistatic agent was large, and was inferior in thermal stability and transparency, and a large amount of gas was generated, and the required level was not satisfied. Comparative Example 3 was a case where the molar ratio (hydroxy group / carboxyl group) between the hydroxy group of the polyhydric alcohol and the carboxyl group of the fatty acid was less than 4, and the surface resistance did not satisfy the required level. In Comparative Example 4, the molar ratio (hydroxy group / carboxyl group) between the hydroxy group of the polyhydric alcohol and the carboxyl group of the fatty acid exceeded 8, and the thermal stability did not satisfy the required level. In Comparative Example 5, the amount of the epoxy polymer having a glycidyl group was small, and the thermal stability and the amount of gas generated did not satisfy the required levels. In Comparative Example 6, the amount of the glycidyl group-containing epoxy polymer was large, and the gas generation amount did not satisfy the required level. In Comparative Example 7, the epoxy polymer was an alicyclic epoxy polymer having no glycidyl group, and the transparency did not satisfy the required level.

Claims (6)

  (A) An epoxy polymer containing 0.5 to 5 parts by weight of an ester compound (B component) composed of a polyhydric alcohol and a fatty acid and (C) a glycidyl group with respect to 100 parts by weight of the polycarbonate resin (component A). C component) contains 0.003 to 0.5 parts by weight, and the molar ratio (hydroxy group / carboxyl group) of the hydroxy group of the polyhydric alcohol and the carboxyl group of the fatty acid in the B component is in the range of 4 to 8. An antistatic polycarbonate resin composition characterized by that.   2. The antistatic polycarbonate resin composition according to claim 1, wherein 0.005 to 1 part by weight of (D) phosphorus antioxidant (D component) is contained with respect to 100 parts by weight of component A. 3.   The antistatic polycarbonate resin composition according to claim 2, wherein the D component is a phosphite-based antioxidant.   The antistatic polycarbonate resin composition according to claim 1, wherein the polyhydric alcohol in component B is diglycerin.   The antistatic polycarbonate resin composition according to claim 1, wherein the component C is a copolymer containing glycidyl methacrylate.   A molded article formed by molding the antistatic polycarbonate resin composition according to any one of claims 1 to 5.