JP4895276B2 - Antistatic polycarbonate resin composition - Google Patents

Description

  The present invention relates to an antistatic polycarbonate resin composition comprising a polycarbonate resin, a specific antistatic agent and a specific ultraviolet absorber, and having excellent transparency, antistatic properties and light resistance.

  Polycarbonate resins are excellent in impact resistance, heat resistance, and transparency, and are widely used in various fields such as electric / electronic, optical, building materials, medical, food, and vehicles. However, products obtained from polycarbonate resin are easily charged with static electricity, and there is a possibility of dust and foreign matter adhering to the surface and failure due to static electricity.

  Conventionally, in order to impart antistatic performance, conductive carbon black or carbon fiber is blended in a polycarbonate resin. However, since they exhibit black color, the color tone of the obtained antistatic polycarbonate resin is limited to black, so it is difficult to color other colors, so the range of use is extremely limited after all. There was a problem of becoming.

In addition to metal blacks, metal salts of alkane sulfonates and metal salts of alkylbenzene sulfonic acids were generally used as antistatic agents for applications other than black. Could not be used.
However, exterior parts of office equipment such as optical disk cartridges are required to be transparent so that the inside can be visually recognized and no dust adheres.

  Furthermore, as an antistatic technique for maintaining transparency with respect to the polycarbonate resin, a method of blending a phosphonium salt of a sulfonic acid (Japanese Patent Laid-Open No. 62-230835), a method of blending a phosphonium salt of a sulfonic acid and a phosphorous ester (special feature) Kaihei 1-14267) has been proposed. However, the polycarbonate resins obtained by these methods have a problem of discoloration due to poor light resistance, and are difficult to apply to light source peripheral members.

JP-A-62-230835 JP-A-1-14267

  For the purpose of imparting light resistance to a polycarbonate resin, it has been conventionally studied to add a benzotriazole-based or benzophenone-based UV absorber. However, when this method is applied to an antistatic polycarbonate resin, there is a problem that the initial hue is yellowish (initial coloring).

  An object of the present invention is to provide an antistatic polycarbonate resin composition having transparency, little initial coloring, and excellent antistatic properties and light resistance, and a molded product formed by molding the same. To do.

As a result of intensive studies to solve the above-mentioned problems, the inventors have blended a specific antistatic agent and a specific ultraviolet absorber with a polycarbonate resin, so that they are excellent in transparency and antistatic properties, and initial coloring. It has been found that an antistatic polycarbonate resin composition having a small amount of light and good light resistance can be obtained, and the present invention has been completed.

That is, according to the present invention, 0.1 to 20 parts by weight of an organic sulfonic acid phosphonium salt (B) represented by the following general formula (1) as an antistatic agent and 100 parts by weight of the polycarbonate resin (A) and the following general formula (2) It is intended to provide an antistatic polycarbonate resin composition characterized by comprising 0.01 to 0.8 parts by weight of an ultraviolet absorber (C) represented by formula (1) and a molded product comprising the same.
General formula (1)

（一般式（１）中、Ｒ１は炭素数１〜４０のアルキル基又はアリール基であり、Ｒ２〜Ｒ５は水素原子、炭素数１〜１０のアルキル基又はアリール基であり、これらは同じであっても異なっていてもよい。）
一般式（２）

(In General Formula (1), R1 is a C1-C40 alkyl group or aryl group, R2-R5 is a hydrogen atom, a C1-C10 alkyl group, or an aryl group, and these are the same. Or different.)
General formula (2)

（一般式（２）中、Ｒ１は炭素数１〜１２のアルキル基、Ｒ２は炭素数１〜１２のアルコキシ基を表す。）

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.)

  The antistatic polycarbonate resin composition of the present invention is excellent in transparency and antistatic properties, has little initial coloration and has good light resistance, and therefore requires high optical performance, and dust adhesion is avoided. Furthermore, it is suitably used for a light source peripheral member or the like that requires light resistance.

  The polycarbonate resin (A) used in the present invention is obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted, or a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. A typical example of the polymer 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 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, and more preferably 17,000 to 28,000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

The antistatic agent (B) used in the present invention is a phosphonium salt of an organic sulfonic acid represented by the following general formula (1).
General formula (1)

（一般式（１）中、Ｒ１は炭素数１〜４０のアルキル基又はアリール基であり、Ｒ２〜Ｒ５は水素原子、炭素数１〜１０のアルキル基又はアリール基であり、これらは同じであっても異なっていてもよい。）

(In General Formula (1), R1 is a C1-C40 alkyl group or aryl group, R2-R5 is a hydrogen atom, a C1-C10 alkyl group, or an aryl group, and these are the same. Or different.)

Among the antistatic agents (B) represented by the general formula (1), an antistatic agent represented by the following general formula (3) can be preferably used.
General formula (3)

The compounding quantity of the antistatic agent (B) used by this invention is 0.1-20 weight part per 100 weight part of polycarbonate resin (A). If the blending amount is less than 0.1 parts by weight, the antistatic property is inferior, and if it exceeds 20 parts by weight, the initial coloration becomes remarkable due to the decrease in thermal stability, which is not preferable. More preferably, it is the range of 1.0-7 weight part.

The ultraviolet absorber (C) used in the present invention is a compound represented by the following general formula (2).
General formula (2)

（一般式（２）中、Ｒ１は炭素数１〜１２のアルキル基、Ｒ２は炭素数１〜１２のアルコキシ基を表す。）

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.)

As a specific example of the compound represented by the general formula (2), an aryl group substituted with an alkyl group and an aryl group substituted with an alkoxy group are symmetrically substituted with respect to two nitrogen atoms in the oxanilide skeleton. In particular, a compound represented by the following general formula (4) is preferably used.
General formula (4)

The ultraviolet absorber is easily available as a commercial product, and examples include Sanduvor VSU manufactured by Clariant Japan.

As a compounding quantity of the ultraviolet absorber (C) used by this invention, it is 0.01-0.8 weight part per 100 weight part of polycarbonate resin (A). A blending amount of less than 0.01 part by weight is not preferable because sufficient light resistance cannot be obtained. On the other hand, if it exceeds 0.8 parts by weight, the thermal stability is deteriorated, which is not preferable. More preferably, it is the range of 0.05-0.6 weight part.

  In the antistatic polycarbonate resin composition of the present invention, various known additives, polymers, and the like can be added as necessary depending on the performance required in addition to the antistatic property in practice. For example, in order to suppress discoloration of a resin molded product when exposed to light for a long time, a hindered amine-based light-resistant stabilizer is used, and in order to obtain a vivid color tone, a benzoxazole-based fluorescent whitening agent and These may be added in combination.

  In the antistatic polycarbonate resin composition of the present invention, known additives other than those described above, such as phenol-based or phosphorus-based heat stabilizer [2,6-di-tert-butyl-4-methylphenol, 2- (1 -Methylcyclohexyl) -4,6-dimethylphenol, 4,4'-thiobis- (6-tert-butyl-3-methylphenol), 2,2-methylenebis- (4-ethyl-6-tert-methylphenol) , N-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris (2,4-di-tert-butylphenyl) phosphite, 4,4′-biphenylenediphosphinic acid tetrakis -(2,4-di-t-butylphenyl), etc.], lubricant [paraffin wax, n-butyl stearate, synthetic beeswax, natural beeswax, glycerol monoe Tellurium, montanic acid wax, polyethylene wax, pentaerythritol tetrastearate, etc.], colorant [eg titanium oxide, carbon black, dye], filler [calcium carbonate, clay, silica, glass fiber, glass sphere, glass flake, carbon Fiber, talc, mica, various whiskers, etc.], fluidity improver, spreading agent [epoxidized soybean oil, liquid paraffin, etc.], and other thermoplastic resins and various impact modifiers (polybutadiene, polyacrylic acid) A rubber-reinforced resin obtained by graft polymerization of a compound such as methacrylic acid ester, styrene, acrylonitrile, etc. to a rubber such as an ester or ethylene / propylene rubber may be added as necessary.

  There is no restriction | limiting in the embodiment and order in this invention. For example, a polycarbonate resin (A), an antistatic agent (B), and a UV absorber (C) having a specific structure are weighed in arbitrary amounts and mixed together with a tumbler, riboblender, high-speed mixer, etc. Melting and kneading using a single-screw extruder or twin-screw extruder and pelletizing, or individually or all of individual components are weighed separately and fed into the extruder from multiple feeders, and melted A method of mixing, further, blending (B) and (C) at a high concentration in (A), once melt-mixed and pelletized to obtain a masterbatch, and then the masterbatch and the polycarbonate resin (A), It can also be mixed in a desired ratio. Then, when these components are melt-mixed, arbitrary conditions such as the position to be fed into the extruder, the extrusion temperature, the screw rotation speed, and the supply amount can be selected and pelletized. Further, the master batch and the polycarbonate resin (A) can be dry-mixed at a desired ratio, and then directly fed into an injection molding device or a sheet extruder device to form a molded product.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. Unless otherwise specified, “%” and “part” in the examples are based on weight standards.

The raw materials used are as follows.
Polycarbonate resin:
Caliber 200-13 manufactured by Sumitomo Dow
(Viscosity average molecular weight: 21500, hereinafter abbreviated as PC)
Antistatic agent:
S-418, Takemoto Yushi Co., Ltd.
(Phosphonium salt of alkylbenzene sulfonic acid, hereinafter abbreviated as antistatic agent)
UV absorber:
Sanduvor VSU made by Clariant Japan
N- (2-Ethylphenyl) -N ′-(2-ethoxyphenyl) oxalic acid diamide (Oxanilide ultraviolet absorber, hereinafter abbreviated as UVA)

Each of the above-mentioned various raw materials was put into tumblers at the blending ratios shown in Tables 1-2, and after dry mixing for 10 minutes, a twin-screw extruder (TEX30α (L / D = 42, Φ = 30 mm)) and kneaded at a melting temperature of 260 ° C. to obtain pellets. A test piece having a width of 50 mm, a length of 90 mm, and a thickness of 2 mm was prepared by using an injection molding machine (J100EII-P manufactured by Nippon Steel Works) under the condition of 290 ° C. using the obtained pellet.

Various evaluation items and measurement methods in the present invention will be described.

1. Surface resistivity (Rs):
The obtained test piece was conditioned for 24 hours under the conditions of 23 ° C. and 50% relative humidity, and then using a superinsulator (SME 8311 manufactured by Sicid Electrostatic Co., Ltd.) with a measurement voltage of 500 V and a sampling time of 60 seconds. The surface resistivity was measured. The case where the surface specific resistance Rs was less than 1 × 10 ¹⁴ was regarded as acceptable.
2. Half-life:
Using the obtained test piece, the half-life was measured with a Static Honestometer H-0110 manufactured by Sicid. First, 10 KV of electric charge is continuously applied until the withstand voltage of the test piece becomes constant, then the charge is stopped, the decay of the charged voltage is observed, and the time until the initial charged voltage is halved is measured to determine the half-life. It was.
A half-life of 20 seconds or less was accepted.
3. Total light transmittance The total light transmittance was measured based on JIS K7361 using the obtained test piece. More than 85% was accepted.
5). Initial coloring and evaluation of light resistance A test piece prepared by an injection molding machine was cut into (3 cm × 3 cm × 2 mm thickness) and placed in an ultra-accelerated weathering tester iSuper UV Tester (SUV-W13 manufactured by Iwasaki Electric Co., Ltd.). For 6 hours. Thereafter, the yellowness index (YI) of the sample before and after irradiation was measured with a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory) in accordance with ASTM D-1925. YI represents the degree of yellowness before irradiation. The smaller the YI, the smaller the yellowishness and the less the initial coloring.
As the evaluation criteria for YI, those with a YI value of less than 5 were accepted (◯), and those with a YI value of 5 or more were rejected (x).
ΔYI represents the degree of yellowness before and after irradiation. The smaller ΔYI, the smaller the color change and the better the light resistance. As the evaluation criteria for ΔYI, those having a value of ΔYI of less than 12 were accepted (◯), and those having a value of 12 or more were rejected (x).

As shown in Table 1, when the polycarbonate resin composition satisfied the requirements of the present invention (Examples 1 to 5), all necessary performances including the surface resistivity value satisfied the required level. .

On the other hand, as shown in Table 2, when the configuration of the present invention was not satisfied, each case had some drawbacks.
The comparative example 1 is a case where the compounding quantity of the ultraviolet absorber of this invention is less than a regulation amount, and resulted in inferior light resistance.
The comparative example 2 is a case where the compounding quantity of the ultraviolet absorber of this invention is larger than a regulation amount, and resulted in the initial YI being inferior.
Comparative Example 3 was a case where the blending amount of the antistatic agent of the present invention was less than the prescribed amount, resulting in poor surface resistivity and half-life.
Comparative Example 4 is a case where the blending amount of the antistatic agent of the present invention is larger than the specified amount, and the transmittance and initial YI were inferior.

Claims (5)

0.1-100 parts by weight of an organic sulfonic acid phosphonium salt (B) represented by the following general formula (1) as an antistatic agent per 100 parts by weight of the polycarbonate resin (A) and an ultraviolet light represented by the following general formula (2) An antistatic polycarbonate resin composition comprising 0.01 to 0.8 parts by weight of an absorbent (C).
General formula (1)

(In General Formula (1), R1 is a C1-C40 alkyl group or aryl group, R2-R5 is a hydrogen atom, a C1-C10 alkyl group, or an aryl group, and these are the same. Or different.)
General formula (2)

(In General Formula (2), R1 represents an alkyl group having 1 to 12 carbon atoms, and R2 represents an alkoxy group having 1 to 12 carbon atoms.) The antistatic polycarbonate resin composition according to claim 1, wherein the antistatic agent (B) is a phosphonium salt of an alkylbenzenesulfonic acid represented by the following general formula (3).
General formula (3)

The antistatic polycarbonate resin composition according to claim 1 or 2, wherein the blending amount of the antistatic agent (B) is 1.0 to 7 parts by weight per 100 parts by weight of the polycarbonate resin (A). object. The antistatic polycarbonate resin composition according to any one of claims 1 to 3, wherein the ultraviolet absorber (C) is a compound represented by the following general formula (4).
General formula (4)

The molded article formed by shape | molding the antistatic polycarbonate resin composition as described in any one of Claims 1-4.