JP2007045909A - Polycarbonate resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin composition excellent in moldability and capable of attaining thin-wall products, in the resin composition suitable for key for cellular phones or personal digital assistances. <P>SOLUTION: The polycarbonate resin composition comprises (A) 100 pts.wt. polycarbonate resin, (B) 1-20 pts.wt. phosphazene compound, (C) 0.005-1 pt.wt. heat stabilizer and (D) 0.01-2 pts.wt. mold-releasing agent. The key for personal digital assistances or cellular phones is obtained by molding the resin composition. Since the polycarbonate resin composition is extremely excellent in balance of various kinds of performances such as moldability, heat resistance, strength, transparency and mold release properties, the resin composition can extremely suitably be used for key for cellular phones or personal digital assistances. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a polycarbonate resin composition suitable for a key for a cellular phone or a portable information terminal.

Conventionally, keys for mobile phones and portable information terminals have been manufactured by injection molding polycarbonate resin. In recent years, however, this application has become increasingly lighter, thinner, and smaller, and the keys used for this have become increasingly thin, making molding by injection molding extremely difficult with conventional polycarbonate resins. It has become a situation.

Although attempts have been made to apply an optical polycarbonate resin having an extremely low molecular weight, there are still problems in terms of moldability and strength.

Although materials such as polycarbonate resin and other resin alloys and amorphous polyester resins have been tried, they still have their merits and demerits, and there are various performance aspects such as moldability, economy, and optical characteristics. Absent.

JP 2004-346112 A JP-A-2005-044130

Therefore, it has been desired to develop a resin composition that can solve the above-described problems and that can realize thinning with excellent moldability.

As a result of intensive studies to achieve the above object, the present inventor has blended specific amounts of a phosphazene compound (B), a heat stabilizer (C) and a release agent (D) with respect to the polycarbonate resin (A). By using the composition thus formed, the above-mentioned problems were solved at once, and a resin composition extremely suitable as a mobile phone or a portable information terminal key having excellent moldability was successfully obtained.

That is, the present invention comprises polycarbonate resin (A) 100 parts by weight, phosphazene compound (B) 1-20 parts by weight, heat stabilizer (C) 0.005-1 part by weight, mold release agent (D) 0.01- The present invention provides a polycarbonate resin composition comprising 2 parts by weight, and a portable information terminal or a form telephone key formed by molding the polycarbonate resin composition.

The polycarbonate resin composition according to the present invention is extremely suitable for use in mobile phones and portable information terminal keys because it has an excellent balance of various properties such as moldability, heat resistance, strength, transparency, and releasability. it can.

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 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 (A) is from 16000 to 22000, preferably from 17000 to 20000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

The phosphazene compound (B) used in the present invention is, for example, a linear phosphazene represented by the following general formula (1) described in “Studies in Inorganic Chemistry 6 Phosphorus (Third Edition)” (ELSEVIER) and Examples thereof include cyclic phosphazenes represented by the following general formula (2).
General formula (1)

一般式（２）

General formula (2)

In the general formulas (1) and (2), n is an integer of 0 to 15, preferably 1 to 10, and R is an arbitrary function selected from an alkyl group, an allyl group, an alkoxy group, an allyloxy group, an amino group, and a hydroxy group. Indicates a group. The alkoxy group and allyloxy group may be modified with an alkyl group, an allyl group, an amino group, a hydroxy group, or the like. The amino group may be modified with an alkyl group, an allyl group, or the like. Specific examples of the phosphazene compound used in the present invention include propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene, fluoroalkylphosphazene and the like. In particular, phenoxyphosphazene is preferable in view of its synthesis method and availability. These may be one kind or a mixture of two or more kinds, and may be a mixture of cyclic and linear. Further, in the phosphazene compound used in the present invention, all R in the same molecule may be the same functional group, or two or more different functional groups. Specific examples of such mixed substituted phosphazene compounds include phosphazene compounds in which a part of the molecule is substituted with a phenoxy group and then substituted with a propoxy group, that is, phenoxypropoxyphosphazene. Commercially available phosphazenes can generally be those synthesized by substituting chlorophosphazene with alcohol, phenol or the like.

The compounding quantity of a phosphazene compound (B) is 1-20 weight part with respect to 100 weight part of polycarbonate resin (A). If the blending amount is less than 1 part by weight, sufficient moldability (fluidity) is difficult to obtain, and conversely if the blending amount exceeds 20 parts by weight, the heat resistance and mechanical strength are greatly reduced, which is not preferable. . Preferably, it is 5-15 weight part, More preferably, it is the range of 7-10 weight part.

The heat stabilizer (C) of the present invention is not particularly limited as long as it can be mixed with the polycarbonate resin (A) and can suppress an increase in yellowing degree during molding. Above all,
Phosphites, phosphonite heat stabilizers and the like have a large effect of suppressing the increase in yellowing and can be suitably used. These are all available as products such as Irgafos 168 and Irgafos P-EPQ from Ciba Specialty Chemicals.

The compounding quantity of a heat stabilizer (C) is 0.005-1 weight part per 100 weight part of polycarbonate resin (A).

When the blending amount of the heat stabilizer (C) is less than 0.005 parts by weight, the effect of suppressing yellowing in the case of pelletizing or injection molding the composition is poor, and conversely when it exceeds 1 part by weight. In the injection molding process, mold contamination due to the heat stabilizer occurs, which is not preferable. Preferably it is 0.01-0.4 weight part, More preferably, it is the range of 0.03-0.2 weight part.

The release agent (D) used in the present invention is not particularly limited as long as it can be mixed with the polycarbonate resin (A) to improve the release property at the time of molding. In particular, organic compounds such as beeswax, glycerol monostearate, glycerol tristearate, pentaerythritol saturated ester, montanic acid ester wax, and carboxylic acid ester exhibit excellent releasability and are preferably used. These include, for example, the beeswax and golden brands of Miki Chemical Industry Co., Ltd., Riken Vitamin Riquemar S-100A and SL-900, Cognis Japan Roxyol VPG861, Clariant Japan RicoWax E, Cognis Japan Roxyol EP- 32.

The compounding quantity of a mold release agent (D) is 0.01-2 weight part per 100 parts of polycarbonate resin.

If the compounding amount of the mold release agent (D) is less than 0.01 parts by weight, the mold release property from the mold during the injection molding process is not sufficient. Occurs and the productivity of the molded product is remarkably lowered. More preferably, it is 0.05-1 weight part, More preferably, it is 0.1-0.4 weight part.

  The polycarbonate resin composition of the present invention contains a known additive such as a phenolic antioxidant [eg, 2,6-di-t-butyl-4-methylphenol, 2- (1-methylcyclohexyl) -4, 6-dimethylphenol, 4,4'-thiobis- (6-t-butyl-3-methylphenol), 2,2-methylenebis- (4-ethyl-6-t-methylphenol), etc.], ultraviolet absorbers [ pt-butylphenyl salicylate, 2,2'-dihydroxy-4-methoxybenzophenone, 2- (2'-hydroxy-4'-n-octoxyphenyl) benzotriazole, etc.], spreading agent [liquid paraffin, epoxy And other thermoplastic resins such as polyethylene terephthalate, polybutylene terephthalate, amorphous polyester, and styrene. The system resin or the like may be added as needed.

There is no restriction | limiting in the form and order at all about the mixing | blending components (A), (B), (C) and (D) mixing method of this invention. For example, an organic solvent solution, powder, a method of adding (B), (C), (D) to a polycarbonate resin (A) in a pellet state, or (B), (C) in a molten polycarbonate resin (A) , (D) can be freely performed. In addition, a method in which all the components are mixed at once with a tumbler, ribbon blender, high-speed mixer, or the like, a method in which arbitrary components are once mixed with these mixers, and then the remaining components are blended. And these mixtures are melt-kneaded and pelletized using a normal single-screw or twin-screw extruder.

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.

The raw materials used for pelletizing the resin composition are as follows.
1. Polycarbonate resin:
Caliber 200-20 natural manufactured by Sumitomo Dow (molecular weight: 19000, hereinafter abbreviated as “PC”)
2. Phosphazene compounds:
CP-134H manufactured by Chemipro Kasei Co., Ltd.
(Hereinafter abbreviated as “PZ”)
Phosphonite heat stabilizer:
Irgaphos P-EPQ manufactured by Ciba Specialty Chemicals
(Hereinafter abbreviated as “stabilizer”)
Release agent:
Natural beeswax golden brand manufactured by Miki Chemical Industry Co., Ltd. (hereinafter abbreviated as “release agent”)

-After the resin composition pelletized polycarbonate resin, phosphazene compound, phosphonite heat stabilizer, and release agent were dry-mixed by a tumbler based on the blending ratios in Table 1, the melt temperature was 250 ° C under the condition of 37 mm in the same direction. It was melt blended by a shaft extruder (KTX37 manufactured by Kobe Steel) to obtain various pellets.

Processing by key injection molding Using pellets obtained by a 75-ton injection molding machine (manufactured by Nippon Steel Co., Ltd.), at a melting temperature of 330 ° C. (injection speed: high speed), the thickness of the thinnest part is 0.1 mm. A key for mobile phone was molded and various data were collected.
The results are shown in Table 1.

(Test method, evaluation method)
It was visually confirmed whether or not the short shot molded product was completely filled.
If there was a short shot, it was considered bad.
Yellowness (YI)
Press the molded product (key) under the condition of 250 ° C, size 5
A flat plate test piece of 0 × 50 × 3 mm (thickness) was prepared. Using the test piece,
ASTM D- by spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory)
The yellowing degree (YI) was measured based on the 1925 method. A numerical value of 7 or less was accepted.
The heat-resistant test molded product was left in a hot air circulating oven at 80 ° C. for 2 hours, and the presence or absence of deformation after the test was visually confirmed. If there was deformation, it was rejected.
4). Releasability Injection molded part (key with runner). The releasability at the time of mold release was evaluated by visual and auditory sense (squeak noise level) and the degree of deformation or breakage of the molded product.
Good (◯) was accepted and bad (x) was rejected.

As shown in Table 1, each compounding component and those whose compounding amounts satisfy the specified range (Examples 1 to 4) satisfied the standards over all evaluation items.

In Table 1, the compounding amounts of the essential components of the present invention that did not satisfy the specified range (Comparative Examples 1 to 4) each had a defect.
In Comparative Example 1, the compounding amount of the phosphazene compound was further smaller than the lower limit of the specified range, and a short shot occurred in the molded product.
In Comparative Example 2, the amount of the heat stabilizer was less than the lower limit of the specified range, and the YI value did not satisfy the standard.
In Comparative Example 3, the compounding amount of the release agent was smaller than the lower limit of the specified range, and the release property was rejected.
In Comparative Example 4, the compounding amount of the phosphazene compound exceeded the upper limit of the specified range, and the molded product was greatly deformed and rejected in the heat resistance test. In addition, the YI value exceeded the standard and was not acceptable.

Claims (5)

It consists of 100 parts by weight of polycarbonate resin (A), 1 to 20 parts by weight of phosphazene compound (B), 0.005 to 1 part by weight of heat stabilizer (C) and 0.01 to 2 parts by weight of release agent (D). A polycarbonate resin composition characterized by the above. The polycarbonate resin composition according to claim 1, wherein the heat stabilizer (C) is a phosphorous heat stabilizer of phosphite and / or phosphonite type. The mold release agent (D) is one or more compounds selected from beeswax, glycerol monostearate, glycerol tristearate, pentaerythritol saturated ester, montanic acid ester wax, and carboxylic acid ester. The polycarbonate resin composition as described. The key for portable information terminals shape | molded from the polycarbonate resin composition of any one of Claims 1-3. A cellular phone key molded from the polycarbonate resin composition according to any one of claims 1 to 3.