JPS641507B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a fiber-reinforced polyester resin composition that exhibits less warpage when formed into a molded product, and is suitable for use in resin parts for automobiles, aircraft, ships, electric/electronic equipment, and other industrial applications, especially high-grade resin parts. Suitable for use in high-strength, precision parts. [Prior art] ○A JP 53-71611 Polybutylene terephthalate 65 to 99% by weight and the molar ratio of terephthalic acid/isophthalic acid
This is an invention of a thermoplastic polyester resin composition consisting of 1 to 35% by weight of polyethylene (tele/isophthalate) of 85/15 to 15/85, and when reinforced with glass fiber, the above polyethylene (tele/isophthalate) is used. It is stated that there is less warpage than when polyethylene terephthalate is used instead or when polyethylene terephthalate is used instead. ○B JP-A-57-149350 100 parts by weight of a copolyester resin with a halogen content of 3 to 15% by weight, which is obtained by copolymerizing a halogen-containing aromatic diol, and an aspect ratio of 5
This is an invention of a polyester resin composition containing 5 to 100 parts by weight of the above glass flakes, and it is stated that when reinforced with a fibrous reinforcing agent, there is less warpage than when no glass flakes are used. There is. [Problems to be solved by the invention] The inventions in ○A and ○B of the prior art above relate to polyester resin compositions with less warpage, but when used for precision parts, they are still sufficiently satisfactory in terms of warpage. It wasn't something I could do. The present invention provides a polyester resin composition with improved warpage without impairing moldability or mechanical properties. [Means for solving the problem] Polybutylene terephthalate Polybutylene terephthalate used in the present invention is a polyester resin obtained by polycondensing terephthalic acid or a dialkyl ester of terephthalic acid and 1,4-butanediol. . The terephthalic acid constituting the above polybutylene terephthalate is partially composed of isophthalic acid, hexahydroterephthalic acid, diphenyldicarboxylic acid,
It may also be replaced with a dibasic acid such as adipic acid or azelaic acid or a polybasic acid such as trimesic acid or trimellitic acid.
Diols such as diethylene glycol, hexamethylene glycol, cyclohexanedimethanol, neopentyl glycol, bisphenol A, halogen-containing bisphenol A, or polyhydric alcohols such as glycerin and pentaerythritol may be substituted. The intrinsic viscosity of polybutylene terephthalate (measured at 30° C. using a mixed solvent of phenol and tetrachloroethane in a weight ratio of 1:1) is preferably in the range of about 0.6 to 1.5. -1 Polyethylene (tere/isophthalate) Polyethylene is produced by mixing terephthalic acid or its dialkyl ester and isophthalic acid or its dialkyl ester, and polycondensing the mixture with ethylene glycol. The isophthalic acid component is preferably 3 mol % or more, particularly 5 to 20 mol %, based on the total amount of the terephthalic acid component and the isophthalic acid component. Part of the above ethylene glycol is
Diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, bisphenol A, halogen-containing bisphenol A, or polyols such as glycerin and pentaerythritol. It may also be replaced with a hydric alcohol. If the molar ratio of the isophthalic acid component in polyethylene (tere/isophthalate) is too small, when polybutylene terephthalate and polyethylene (tere/isophthalate) are mixed to make a mixed polyester, the isophthalic acid component of the mixed polyester will be It becomes impossible to obtain the desired amount, and the effects of the present invention cannot be expected. -2 Polyethylene isophthalate Polyethylene isophthalate is produced by polycondensing isophthalic acid or its dialkyl ester with ethylene glycol. Ethylene glycol is mentioned above.
As in 1, some parts can be replaced by other substances. The polyester mixture used in the present invention is a mixture of the above-mentioned polybutylene terephthalate and the above-mentioned polyethylene (tere/isophthalate) (1) and/or -2 (polyethylene isophthalate). Polybutylene terephthalate in the polyester mixture is 90-20% by weight, preferably 80-30%
% by weight, -1 polyethylene (tele/isophthalate) and/or -2 polyethylene isophthalate from 10 to 80% by weight, preferably
20-70% by weight. In this polyester mixture, it is desirable that the isophthalic acid component is 1 to 10 mol%, particularly 2 to 6 mol%, based on the total amount of the terephthalic acid component and the isophthalic acid component in the mixture. Examples of the fibrous reinforcing agent include glass fibers, carbon fibers, and metal whiskers, such as glass fibers with a diameter of 1μ or more and a length of 15μ or more, preferably a diameter of 1.5 to 20μ and a length of about 0.02 to 7mm. Pitch-based, acrylonitrile-based, cellulose-based, and lignin-based carbon fibers having a diameter of 5 to 20 μm and a length of 0.05 to 6 mm, preferably about 0.1 to 2 mm are suitable. The fibrous reinforcing agent is preferably used in an amount of 5 to 100 parts by weight, preferably 10 to 50 parts by weight, per 100 parts by weight of the polyester mixture. If the amount is too large, molding becomes difficult, which is not preferable. The glass flakes used in the present invention have an aspect ratio (ratio of length to thickness) of 5 or more, preferably 10 or more. Specifically, the thickness is 1
~30μ, preferably about 2 to 10μ, with a major axis of ~10μ
The thickness is about 3 mm, preferably about 50 μm to 2 mm.
When the aspect ratio is smaller than 5, the effect of preventing warpage and improving the strength of the weld portion becomes small. On the other hand, there is no problem when using a material with a large aspect ratio, but since it will be crushed during blending with the resin, no effect can be expected from using a material with a particularly large aspect ratio. The amount of glass flakes used is 5 to 100 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the polyester mixture.
10 to 50 parts by weight. If the amount is too small, the warpage prevention effect will be reduced. On the other hand, if the amount is too large, molding becomes difficult, which is not preferable. Further, up to half of the glass flakes can be replaced with glass beads. Next, referring to the compounding means, the fiber reinforcing agent and glass flakes may be treated with an epoxy-based, epoxy-silane-based, or aminosilane-based surface treatment agent in order to improve adhesion to the resin. In order to blend the fibrous reinforcing agent and glass flakes into a polyester mixture, the above raw materials may be mixed in any order.For example, the above raw materials may be mixed and melt kneaded, or a polyester mixture may be prepared and fibers A method of mixing a fibrous reinforcing agent and glass flakes and melting and kneading the mixture, a method of using a master batch of fibrous reinforcing agent and/or glass flakes, etc. can be adopted. Other additives include aromatic halogen compounds, halogen-containing epoxy resins, halogen-containing polycarbonate resins, halogen-containing polyphenylene oxides, flame retardants such as halogen-containing polybenzyl acrylate, flame retardant aids such as antimony trioxide, Combustion prevention agents such as asbestos, silica, alumina, silica alumina, silica magnesia, titania, calcium carbonate, talc, fillers such as gypsum, dyes and pigments, paraffins, fatty acid esters, fatty acid metal salts, bisamides. It is also possible to use lubricants such as these and other well-known additives in combination. [Effects of the Invention] The composition of the present invention has excellent moldability and mechanical properties, and has little warpage, so it is of great value as an engineering plastic. The composition of the present invention can be made into molded products of various shapes such as three-dimensional molded products, various containers, films, sheets, and tubes by various molding methods such as injection, extrusion, blowing, and compression. It is suitable as a material for electronic parts, automobile parts, and other industrial uses. [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 the examples, "parts" and "%" indicate "parts by weight" and "% by weight," respectively. In addition, tensile strength is ASTM D638 bending strength is
Values measured according to ASTM D790 are shown. Moldability was measured at a resin temperature at which sufficient fluidity could be obtained at a pressure of 60 kg/cm ² G when molding the above-mentioned test piece for strength measurement by injection molding. The amount of warpage is 100 mm in diameter molded by injection molding.
A disk with a thickness of 1.6 mm is placed on a flat surface, and the sum of the height of the highest point of the raised periphery and the height of the opposite periphery across the center in mm is shown. . Examples 1 to 4 and Comparative Examples 1 to 2 Polybutylene terephthalate with an intrinsic viscosity of 0.85, a mixture of dimethyl terephthalate and dimethyl isophthalate in a molar ratio of 90:10, and ethylene glycol were polycondensed, and the intrinsic viscosity was 0.75. To 100 parts of a polyester mixture prepared by dry blending polyethylene (tere/isophthalate) in the proportions shown in Table 1 below, glass fiber (manufactured by Asahi Fiberglass Co., Ltd., MA419) in the amount shown in Table 1 below, Glass flakes (manufactured by Nippon Sheet Glass Co., Ltd., CCF48) and glass beads (Toshiba Balloteni) in Example 2
Co., Ltd., EB731B) was mixed and melted and kneaded at 255°C using a 40 mm diameter vented extruder to form extruded pellets. The pellets were molded using a 3.9-ounce injection molding machine (manufactured by Japan Steel Works, Model N-100B) and a mold for forming test pieces specified by ASTM and warpage test pieces of 100 mmφ x 1.6 mm. Mold temperature 80℃, injection pressure 60
Molding was carried out at Kg/cm ² G, injection time 7 seconds, and cooling time 10 seconds. The physical properties and moldability of the obtained molded product are as follows:
It was as shown in the table. In addition, for comparison, the case where glass flakes and glass beads were not used (Comparative Example 1), the case where the amount of polyethylene (Tele/Isophthalate) was small (Comparative Example 3), and the case where the amount of polyethylene (Tele/Isophthalate) was The results obtained when polyethylene terephthalate having an intrinsic viscosity of 0.70 was used alone (Comparative Example 2) are also shown.

[Table] Examples 5 to 7 Polyethylene (tele/
isophthalate), the molar ratio of dimethyl terephthalate and dimethyl isophthalate is 85:15.
Polyethylene (tere/isophthalate) having an intrinsic viscosity of 0.75 obtained by polycondensing a mixture of The results shown in Table 2 below were obtained.

[Table] Example 8 and Comparative Examples 4 to 6 100 parts of a polyester mixture containing the same polybutylene terephthalate and polyethylene (tere/isophthalate) of 60:40 as used in Example 1, 15 parts of glass fiber, and glass flakes. 20 parts, polybromophenylene oxide (manufactured by Great Lakes Co., Ltd.,
Flame retardant P0-64P) 3.5 parts and antimony trioxide
Mix 3.5 parts and use a 40mmφ vented extruder.
Pellets of extruded flame-retardant polyester resin composition were produced by melt-kneading at 255°C. When this pellet was injection molded in the same manner as in Example 1, the results shown in Table 3 below were obtained. For comparison, when glass flakes were not used (Comparative Example 4), when the amount of polyethylene (tele/isophthalate) was small (Comparative Example 5),
Also shown are the results when polyethylene terephthalate was used alone instead of polyethylene (tere/isophthalate) (Comparative Example 6).

【table】

Claims (1)

[Scope of Claims] 1. Polyethylene (tere/isophthalate) and/or polyethylene containing 90 to 20% by weight of polybutylene terephthalate and an isophthalic acid component of 3 mol% or more based on the total amount of the terephthalic acid component and the isophthalic acid component. Isophthalate 10-80
100 parts by weight of a polyester mixture consisting of 5 to 100 parts by weight of a fibrous reinforcing agent and 5 to 100 parts by weight of glass flakes.