JPH0372666B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to polybutylene terephthalate compositions. Specifically, the present invention relates to a polybutylene terephthalate composition that has excellent impact resistance and hydrolysis resistance and is useful for use as electrical/electronic parts, automobile parts, and other industrial materials. [Prior art] Compositions with improved impact resistance made of polybutylene terephthalate and acrylic rubber are known (Japanese Patent Application Laid-open No. 150466/1983), but mechanical properties deteriorate when hydrolyzed under high temperature and high humidity. The tendency for this to decrease is greater than that of polybutylene terephthalate itself. [Object of the Invention] The present inventors have conducted intensive research to improve the above-mentioned drawbacks, and have found that when blending halogen-free aromatic epoxy resin with acrylic rubber into polybutylene terephthalate, impact resistance and The present invention was completed based on the knowledge that a polybutylene terephthalate composition having excellent hydrolyzability can be obtained. [Structure of the Invention] The gist of the present invention is an acrylic rubber obtained by graft polymerizing a graft polymerizable monomer to a polymer obtained by polymerizing polybutylene terephthalate, an acrylic acid ester, and a small amount of a crosslinkable monomer, and a halogen-free acrylic rubber. A polybutylene terephthalate composition comprising an aromatic epoxy compound, wherein the ratio of polybutylene terephthalate to acrylic rubber is 99.5:0.5 to 70:30 by weight, and
The polybutylene terephthalate composition with improved hydrolysis resistance has an amount of halogen-free aromatic epoxy compound in an amount of 0.01 to 5% by weight based on the total amount of polybutylene terephthalate and acrylic rubber. The polybutylene terephthalate used in the present invention is a thermoplastic polyester resin obtained by a polycondensation reaction of terephthalic acid or its dialkyl ester and tetramethylene glycols. The acrylic rubber of the present invention is a polymer obtained by polymerizing an acrylic ester such as butyl acrylate and a small amount of a crosslinkable monomer such as butylene diacrylate, and a graft polymerizable monomer such as methyl methacrylate. A rubbery polymer obtained by graft polymerization is used. Examples of the acrylic esters include butyl acrylate, methyl acrylate, ethyl acrylate, propyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and the like. In addition to butylene diacrylate, examples of crosslinking monomers include butylene dimethacrylate, polyols such as trimethylolpropane trimethacrylate, and esters of acrylic acid or methacrylic acid, divinylbenzene, vinyl acrylate, vinyl methacrylate, etc. The compounds include allyl compounds such as allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl itaconate, monoallyl maleate, monoallyl fumarate, and triallyl cyanurate. In addition, as the above graft polymerizable monomer,
In addition to methyl methacrylate, examples include methacrylic acid esters such as ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, styrene, acrylonitrile, and the like. A part of this graft polymerizable monomer can also be copolymerized by using it when producing a polymer by polymerizing the above-mentioned acrylic ester and a crosslinking monomer. The above-mentioned acrylic rubbers include, for example, Kane Ace FM manufactured by Kanebuchi Chemical Co., Ltd., Vitax V-6401 manufactured by Hitachi Chemical Co., Ltd., Metablane W-300 and Mitsubishi Rayon Co., Ltd. W-530, It is also commercially available as Acryloid KM-323, Acryloid KM-330 (trademarks), etc. manufactured by Rohm and Haas. Examples of the halogen-free aromatic epoxy compound include bisphenol A diglycidyl ether, tetraphenyl ethylene epoxide, and phthalic acid diglycidyl ester. The ratio of polybutylene terephthalate to acrylic rubber is 99.5 to 0.5 to 70:30 by weight, preferably 97:3 to 80:20. If the amount of acrylic rubber is too small, a composition with excellent impact resistance cannot be obtained; on the other hand, if the amount is too large, mechanical properties such as tensile strength and bending strength will deteriorate. The amount of epoxy compound is 0.01 based on the total amount of polybutylene terephthalate and acrylic rubber.
-5% by weight, preferably 0.02-2% by weight.
If the amount is too low, no effect can be expected, and on the other hand, if the amount is too high, coloring may occur. In the present invention, better effects can be obtained by adding a carbodiimide compound together with the above-mentioned acrylic rubber and epoxy compound. Carbodiimide compounds are produced, for example, by thermal decarboxylation from isocyanate compounds, and specific examples include diphenylcarbodiimide, ditolylcarbodiimide, di(propylphenyl)carbodiimide, di(butylphenyl)carbodiimide, Dinaphthylcarbodiimide, bis(dipropylphenyl)carbodiimide, polyphenylenecarbodiimide, polytolylenecarbodiimide, poly(propylphenylene)carbodiimide, poly(dipropylphenylene)carbodiimide, poly(diphenylmethane)carbodiimide, polynaphthylenecarbodiimide etc. can be mentioned. The amount of carbodiimide compound is based on the total amount of polybutylene terephthalate and acrylic rubber.
It is 0.01 to 5% by weight, preferably 0.02 to 2% by weight. If it is too small, the effect will be small, and if it is too large, mechanical properties will be adversely affected. Methods for blending the above-mentioned composition include a dry blending method, a method of melt-mixing the dry blend using an extruder and extruding it into pellets,
A well-known method may be employed, such as preparing a master pellet containing a large amount of pentaerythritol ester and/or epoxy compound and mixing this with a diluent pellet. The polybutylene terephthalate composition of the present invention includes reinforcing agents such as glass fiber and carbon fiber, fillers such as silica, alumina, silica alumina, silica magnesia, calcium carbonate, gypsum, and clays, and halogen-containing aromatic compounds. , a flame retardant such as a halogen-containing acrylic resin or a halogen-containing resin such as a polycarbonate resin, a flame retardant aid such as antimony trioxide, and other well-known additives. [Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In addition, "parts" in the examples indicate "parts by weight." Note that the tensile strength is a value measured according to ASTM D638, and the Izod impact strength is a value measured according to ASTM D256. Examples 1 to 2 and Comparative Examples 1 to 2 Methyl Acrylic rubber obtained by graft polymerization of 30 parts of methacrylate, glass fiber (manufactured by Asahi Fiberglass Co., Ltd.,
CS03MA486), and bisphenol A-diglycidyl ether (manufactured by Adeka Argus Chemical Co., Ltd.,
The mixture was prepared with a mixture of trademark EP-17) or a mixture thereof with bis(diisopropylphenyl)carbodiimide, and was melt-kneaded at 250°C using a 40 mmφ extruder and extruded into pellets. This pellet was molded using a 3.9 oz injection molding machine (manufactured by Japan Steel Works, Model N-100BV) and a test piece mold specified by ASTM, at a resin temperature of 258°C, a mold temperature of 80°C, and an injection time of 10°C. Injection molding was performed with a cooling time of 20 seconds. The obtained molded product is placed in a steam sterilizer (Taniguchi Kagaku Co., Ltd.).
under pressurized steam at 120℃ using a
A hydrolysis test was conducted, and the molded product immediately after molding,
The tensile strength and Izot impact strength of the molded product after the 90 hour test were measured. The results were as shown in Table 1 below. For comparison, the results obtained when no epoxy compound was added are also shown.

[Table] Examples 3 to 4 and Comparative Examples 3 to 4 The same operations as in Examples 1 to 2 were performed except that glass fiber was not used, and the results shown in Table 2 below were obtained. However, the hydrolysis test was performed at 90℃ and RH100%.
I did it for 750 hours.

[Table] Examples 5 and 6 Instead of bisphenol A-diglycidyl ether in Example 1, 0.5 part of allyl glycidyl ether (manufactured by Osaka Soda Co., Ltd., trademark, Neo Allyl G) (Example 5), or 3, 4-Epoxycyclohexyl-3',4'-epoxycyclohexanecarboxylate (manufactured by Union Carpide, trademark,
Using 0.5 part of ERL4221) (Example 6), the results shown in Table 3 below were obtained.

[Table] Comparative Examples 5 to 6 In Example 2, ABS (acrylonitrile-butadiene-styrene copolymer; manufactured by Mitsubishi Monsanto Chemical Co., Ltd., trade name: Toughflex 410) was used instead of acrylic rubber as the rubbery polymer. or
The various physical properties were measured in the same manner as in Example 2, except that MBS (methyl methacrylate-butadiene-styrene copolymer; manufactured by Mitsubishi Rayon Co., Ltd., trade name: Metablen C-223) was used. The results are shown in Table 4. Comparative Examples 7 to 8 Various physical properties were measured in the same manner as in Example 4, except that ABS or MBS was used instead of acrylic rubber as the rubbery polymer. The results are shown in Table 4.

〔Effect of the invention〕

The polybutylene terephthalate composition of the present invention can be molded into various shapes such as three-dimensional molded products, sheets, tubes, and monofilaments by various molding methods such as injection molding, extrusion molding, compression molding, and blow molding. Because it has improved hydrolysis resistance, it is of great value as a material for electrical and electronic parts, automobile parts, and other industrial applications.

Claims (1)

[Claims] 1 Polybutylene consisting of an acrylic rubber obtained by graft polymerizing a graft polymerizable monomer to a polymer obtained by polymerizing polybutylene terephthalate, an acrylic acid ester, and a small amount of a crosslinkable monomer, and a halogen-free aromatic epoxy compound. A terephthalate composition in which the ratio of polybutylene terephthalate and acrylic rubber is 99.5:0.5.
~70:30 weight ratio, and the amount of halogen-free aromatic epoxy compound is 0.01 to the total amount of polybutylene terephthalate and acrylic rubber.
~5% by weight of a polybutylene terephthalate composition with improved hydrolysis resistance.