JPH01247456A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate resin composition improved in mold release without detriment to the appearance of a molding, by mixing a polycarbonate resin with a glass fiber and an organopolysiloxane. CONSTITUTION:50-97wt.% polycarbonate resin of a viscosity-average MW of 10000-100000 is mixed with 3-50wt.% glass fiber of a fiber diameter of 6-20mum and a fiber length of 1.5-6mm and 0.5-0.4wt.% organopolysiloxane of the formula (wherein R<1-3> are each H, a 1-6C alkyl or phenyl, and m and n are each 0 or >=1), having a viscosity of 5-100000cst at 25 deg.C.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polycarbonate resin composition, and more particularly to a glass fiber reinforced polycarbonate resin composition that has excellent mold releasability without impairing the appearance of molded products. be.

[Prior Art and Problems to be Solved by the Invention] Polycarbonate resins have poor mechanical strength, electrical properties, LI clarity, etc., and are used in various fields as engineering plastics5. In particular, glass fiber reinforced polycarbonate resin has further improved mechanical strength and is used in various industrial parts.

However, with the expansion of its uses, the shapes of industrial parts have become more complex, and the problem of poor mold release has started to occur when molding the glass fiber reinforced polycarbonate resin. Therefore, a composition containing organopolysiloxane has been proposed for the purpose of improving the mold releasability, rigidity, one-dimensional stability, etc. of the resin (Japanese Patent Publication No. 35929/1983). However, molded products obtained using this composition have a lot of floating glass fibers, and a new problem arises in that a product with a good appearance cannot be obtained.

[Means for Solving the Problems] The present inventors conducted intensive research to solve the above problems, and found that by adjusting the amount of organopolysiloxane blended into glass fiber reinforced polycarbonate, it was possible to avoid deteriorating the appearance. They discovered that the mold releasability could be improved and completed the invention.

That is, the present invention provides (a) polycarbonate resin 50 to
97% by weight, (b) 3-50% by weight of glass fibers and (
c) A polycarbonate resin composition comprising 0.05 to 0.4% by weight of organopolysiloxane is provided.

(a) The polycarbonate resin used in the present invention is prepared by a solvent method,
That is, the reaction of a dihydric phenol with a carbonate precursor such as phosgene or the reaction of a dihydric phenol with a carbonate precursor such as diphenyl carbonate in the presence of a known acid acceptor 9 molecular weight regulator in a solvent such as methylene chloride. It can be produced by transesterification.

Here, dihydric phenols that can be suitably used include bisphenols, and 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) is particularly preferred. Further, part or all of bisphenol A may be substituted with other dihydric phenol. Examples of dihydric phenols other than bisphenol A include hydroquinone, 4,4'-dihydroxydiphenyl, bis(4
-hydroxyphenyl)alkane, bis(4-hydroxyphenyl)cycloalkane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)
Compounds such as sulfone, bis(4-hydroxyphenyl) sulfoxide, bis(4-hydroxyphenyl) ether or bis(3,5-dibromo-4-hydroxyphenyl)propane, bis(3,5-dichloro-4-hydroxy Examples include halogenated bisphenols such as phenyl)propane. These dihydric phenols may be homopolymers or copolymers or blends of two or more dihydric phenols.

In terms of mechanical strength and moldability, the polycarbonate resin used in the present invention has a viscosity average molecular weight of 10,
000-100. Goo's is preferred, especially 15,
000 to 60,000 is suitable.

The blending ratio of the polycarbonate resin, which is the component (a), is 50 to 97% by weight, preferably 60 to 9% by weight, based on the total amount of the composition.
It is 5% by weight.

Next, as the glass fiber (b) used in the present invention, any ordinary glass fiber available on the market can be used, but chopped strands, cut fibers, and milled fibers are particularly preferred. The chopped strand preferably has a glass fiber length of 1.5 to 6 mm and a fiber diameter of 6 to 20 μm, and the cut fiber or milled fiber preferably has a glass fiber length of 0.02 to 1 mm and a fiber diameter of 6 to 20 μm.
Preferably, the thickness is 20μ. These glass fibers can be used alone or in combination. Furthermore,
It may be surface-treated by a conventional method in order to increase its affinity with polycarbonate resin.

The blending amount of these glass fibers is 3 to 50% by weight, preferably 5 to 40% by weight, based on the total amount of the composition. When the amount added is less than 3% by weight, the effect of reinforcing the glass m fibers is small, and when it exceeds 50% by weight, it becomes difficult to knead and mold the composition, which is not desirable.

The organopolysiloxane (c) used in the present invention preferably has a viscosity of 5 to 100 and 0OOcSt at 25°C and is represented by the following structural formula.

(In the formula, Hl, R2, R3 are hydrogen atoms, carbon number 1-6
are an alkyl group or a phenyl group, and may be the same or different. Further, m and n are O or an integer of 1 or more. ) Examples of such organopolysiloxane monomers include dimethylsiloxane and methylphenylsiloxane. The blending amount of these organopolysiloxanes is 0.05 to 0.05% of the total amount of the composition.
It is necessary that the content be 4% by weight. If the amount added is less than 0.4% by weight, there is no effect on mold releasability.
If it exceeds this value, the glass fibers will float and the appearance of the molded product will be poor.

In the present invention, the above (a) polycarbonate resin is usually 50 to 97% by weight, and (b) glass fiber is 3 to 50% by weight.
and (c) organopolysiloxane 0.05-0.4
A composition consisting of % by weight is pelletized using an extruder or the like. The pellets are molded into a desired shape by means such as injection molding depending on the intended use.

[Example code] Next, the present invention will be explained in detail using examples.

Examples 1 to 10 As shown in Table 1, predetermined amounts of (a) polycarbonate resin, (b) glass fiber, and (c) polysiloxane were blended and pelletized at 300°C using a twin-screw extruder.

Injection molding was performed at 300° C. using this pellet, and the mold release properties and appearance of the molded products were evaluated using eGA results, which are shown in Table 1. The mold releasability was evaluated based on the oil pressure when the ejecting bottle of the molding machine ejects the molded product. In this case, the lower the oil pressure, the better the mold releasability, but in practice it is good if it is 20 kg/cm2 or less.

In addition, the appearance of the molded product was visually evaluated, and the criteria for evaluation were as follows.

X...Large glass fiber float △... Same as medium ○...
・Same Small ◎・・・ Same Very Small Comparative Examples 1 to 2 As shown in Table 1, the procedure was carried out in the same manner as Examples 1 to 10, except that the amount of polysiloxane was outside the range of the present invention. . The results are shown in Table 1.

Comparative Examples 3 to 5 Comparative Examples 1 to 10 were carried out in the same manner as in Examples 1 to 10, except that natural paraffin, polyethylene wax, or beeswax was used instead of polysiloxane as shown in Table 1. The results are shown in Table 1.

/ /' (Note) Medium 1 polycarbonate (manufactured by Idemitsu Petrochemical ■) A
: rA 2.500J, molecular weight 23,000B,
rA 2,200J, molecular weight 21,000C: r
A 2,700J, molecular weight 27,000 in 2 glass fiber (manufactured by Nippon Electric Glass ■) D: Chopped strand fiber length 3mm, diameter 13μ E: Milled fiber average fiber length 0.04mm, diameter 9μ *3 Polysiloxane ( Made by Toray Silicone ■) F;
rSH200J (Main component is dimethylsiloxane) a, rsH550J (Main component is methylphenylsiloxane) Medium 4 natural paraffin; manufactured by Hiki Seiro ■, '5PO145゜ Medium 5 polyethylene wax; Mitsui Petrochemical Industries ■ Manufactured by “
Hiwax 400" *6 Beeswax; manufactured by Miki Kagaku ■, "Golden Brand" [Effects of the invention: According to the present invention, a glass fiber-reinforced polycarbonate composition that does not impair the appearance of molded products and has excellent mold releasability. can be obtained.

Therefore, it is possible to obtain a molded product with a complex shape and excellent appearance, which has been difficult to achieve in the past. Therefore, the composition of the present invention
It is useful for manufacturing various electrical and electronic parts such as equipment.

Patent applicant: Idemitsu Petrochemical Co., Ltd.

Claims (1)

Scope of Claims: (a) 50-97% by weight of polycarbonate resin, (b) 3-50% by weight of glass fiber, and (c) 0.05-0.4% by weight of organopolysiloxane.
A polycarbonate resin composition consisting of: