JPS6351453A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition having improved solvent resistance without lowering the transparency of base resin, by compounding a polycarbonate resin with a polyether ester block copolymer having a specific polyether segment content. CONSTITUTION:The objective composition is composed of (A) 90-98wt.% poly carbonate resin derived from bisphenol A and (B) 2-10wt.% polyether ester block copolymer composed of (i) a polyester containing 2-4C alkylene glycol and terephthalic acid as main constituent components and (ii) a polyether containing 2-4C alkylene glycol as main constituent component and having a molecular weight of preferably 500-2,000, especially 600-1,500 (preferably a polyether produced by adding ethylene oxide, etc., to both terminal of bisphenol A) and having a polyether segment content of 10-55wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a polycarbonate resin composition that provides molded articles with excellent chemical resistance.

[Prior art/problems to be solved by the invention] Polycarbonate resin is an engineering resin with excellent heat resistance and impact resistance, and is used in a wide range of industrial fields such as electrical parts, electronic parts, mechanical equipment parts, and automobile parts. ing. However, it has drawbacks in its chemical resistance under stress, particularly its resistance to solvents such as brake oil, which is a major problem especially when used as automobile parts.

In order to improve this drawback, alloying with other resins has been considered, and alloying with ABs resin has achieved some success in the industry, although it is accompanied by a decrease in heat resistance.

However, with this method, another layer of polycarbonate resin
Transparency, which is one of the characteristics of

The present invention was made in order to improve the solvent resistance of polycarbonate resin without impairing its transparency as much as possible.

[Means for Solving the Problems] The present invention uses a polycarbonate resin of 90 to 98% (molding percentage).
, the same applies hereinafter) and the polyether segment content is 10 to 5.
5% polyether ester block copolymer 2~
10% of the polycarbonate resin composition.

[Example 2] The polycarbonate resin used in the present invention refers to polycarbonate of bisphenol A, and this resin is already commercially available, and all of them can be used.

The polyether ester block copolymer used in the present invention refers to a polyester whose main constituents are alkylene glycol having 2 to 4 carbon atoms and terephthalic acid, and a polyether whose main constituents are alkylene glycol having 2 to 4 carbon atoms. It is a block copolymer with Examples of alkylene glycols having 2 to 4 carbon atoms include ethylene glycol, propylene glycol, and butanediol.

The alkylene glycol and terephthalic acid constituting the polyester each contain other glycols (for example, hexanediol, cyclohexane methanol, etc.) and dicarboxylic acids (for example, isophthalic acid, naphthalene dicarboxylic acid, etc.) within a range of 10 moles or less. Good too.

The polyester most advantageously used industrially is
Examples include polyethylene terephthalate.

Specific examples of polyethers whose main component is alkylene glycol having 2 to 4 carbon atoms include polyethylene glycol, polypropylene glycol,
ethylene glycol-propylene glycol copolymer,
Examples include polytetramethylene glycol, polyethylene glycol adducts of bisphenols, and polypropylene glycol adducts of bisphenols.

In order to achieve the object of the present invention, the molecular weight of the polyether is preferably from 500 to 2,000, more preferably from 600 to 1,500. If the molecular weight is less than 500, the solvent resistance of the molded product tends to be insufficient, and if it is greater than 2,000, the transparency tends to decrease.

The shorter the polyalkylene glycol chain length in the polyether, the better the transparency. From this point of view, it is preferable to introduce a segment having a structure different from the alkylene glycol segment into the molecule of the (i) ether. Specific examples of such polyethers include bisphenol A
Examples include polyethers with ethylene oxide, propylene oxide, etc. added to both ends.

In this case, the compatibility with polycarbonate is also improved to give good results.

There is no particular limitation on the molecular weight of the polyether ester block copolymer, but it is usually prepared in a mixed solvent of tetrachloroethane/phenol-50150 (by weight) at 25°C and 0.
．． Logarithmic viscosity (IV) at 5f/dρ is 0.5 to 1.4,
Preferably, 0.7 to 1.2 is used.

There are no particular limitations on the method for producing the polyether ester block copolymer, and any known method may be used.

An example of this method is to prepolymerize bishydroxyethyl terephthalate, then add the polyether, a catalyst such as antimony trioxide, and other additives, and perform melt polycondensation under vacuum.

The composition of the present invention may optionally contain other known resins, such as polyethylene, polypropylene, EP rubber, ethylene-vinyl acetate copolymer, ionomer, polyacrylate, ABS resin, nylon, PBT resin, PET resin, etc. Resins may be blended to impart other properties, and
Fillers such as glass fiber, glass peas, carbon fiber, steel fiber, talc, clay, calcium carbonate, calcium sulfate, mica, carbon powder, pigments such as zinc oxide and titanium oxide, dyes, antioxidants, ultraviolet absorbers,
A flame retardant or the like may be added.

Examples 1 to 2 and Comparative Example 1 Commercially available polycarbonate (Lexan 141 manufactured by GE)
9 (1 to 95 parts (parts by weight, same applies hereinafter)) and PE060
5 to IO parts of a polyethylene terephrate block copolymer containing 25% of 0 (molecular weight approximately 800) segments were melt-blended using a twin screw extruder, and dumbbells were formed by injection molding.

After checking the transparency of this molded product, we used commercially available brake fluid (Brake FluidClas manufactured by Toyo Kogyo Co., Ltd.).
The molded products were immersed in s-S) day and night, and the occurrence of cracks in the molded products was observed. The results are shown in Table 1.

For comparison, a sample that did not use the polyether ester block copolymer was also evaluated in the same manner. The results are shown in Table 1.

In the evaluation of transparency in Table 1, ◎ indicates transparency, and ○ indicates semi-transparency.

[Margin below] Table 1 Example 3 Example 1 except that a polyethylene terephthalate block copolymer containing 30% of bisphenol A polyethylene oxide adduct segments of molecule Q100O was used.
Tested in the same manner.

As a result, the transparency was rated as ◎ to ◎, and no cracks were observed even in the brake oil test.

Example 4 A test was carried out in the same manner as in Example 3, except that 2 parts of a polyethylene terephthalate block copolymer containing 40% of bisphenol A polyethylene oxide adduct segments having a molecular weight of 700 was used and 98 parts of polycarbonate were used. As a result, the transparency was rated as ◎, and no cracks were observed in the brake oil test.

[Effects of the Invention] When the composition of the present invention is used, the solvent resistance of the polycarbonate is improved without significantly impairing the transparency, and therefore, the composition is of great value.

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Claims (1)

[Claims] 1. A polycarbonate resin composition comprising 90 to 98% by weight of a polycarbonate resin and 2 to 10% by weight of a polyether ester block copolymer having a polyether segment content of 10 to 55% by weight.