JPS6112745A - Hollow article of polybutylene terephthalate - Google Patents

Abstract

PURPOSE:To provide a molded article having excellent blow-moldability and impact resistance and high rigidity, by compounding a specific polybutylene terephthalate with an alpha-olefin/alpha,beta-unsaturated acid glycidyl ester copolymer and glass fiber, and molding the mixture. CONSTITUTION:(A) 100pts.(wt.) of a polybutylene terephthalate or its copolymer having an intrinsic viscosity of >=0.5 is compounded with (B) 3-50pts. of a copolymer of an alpha-olefin and an alpha,beta-unsaturated acid glycidyl ester and (C) 3- 80pts. of glass fiber, and the obtained resin composition is blow-molded. The component B is a copolymer of ethylene, propylene, etc. with glycidyl methacrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a polybutylene lentil reflex hollow molded product.

[Conventional technology]

Conventional polybutylene terephthalate contains ethylene and α, β
- A hollow molded body made of a resin composition mixed with a copolymer of an unsaturated acid with a glycidyl ester is known (Japanese Patent Application Laid-open No. 162750/1983).

[Problem that the invention seeks to solve]

This hollow molded product has stable melt flowability during blow molding, so it can be obtained with a relatively uniform wall thickness and good impact resistance, but it lacks rigidity and has a stable shape. There is a problem of insufficient gender.

Therefore, various studies were carried out for the purpose of the present invention, which has both blow moldability and impact resistance, and also solves the above problems.

[Easy way to solve problems]

As a result, (8) 100 parts by weight of polybutylene terephthalate or a copolymer thereof having an intrinsic viscosity of 0.5 or more, ■ 3 to 50 parts by weight of a copolymer of σ-olefin and glycidyl ester of α,β-unsaturated acid. This is achieved by blow-molding a resin composition consisting of 3 to 80 parts by weight of glass fibers to obtain a polybutylene terephthalate blow-molded product.The structure and effects of the present invention will be explained in detail below. Describe.

As the polybutylene terephthalate according to the invention, a homogeneous polymer or copolymer is used, the copolymer comprising a dicarboxylic acid component in which at least 40 mol % is terephthalic acid;

The dicarboxylic acid components other than terephthalic acid include 4-butanediol, aliphatic carboxylic acids having 2 to 20 carbon atoms such as azelaic acid, sepacic acid, adipic acid, and dodecanedioic acid, isophthalic acid, and naphthalene dicarboxylic acid. Examples thereof include aromatic dicarboxylic acids such as, and alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid, alone or in mixtures.

A preferred copolymer contains 40 mol% or more of terephthalic acid;
It is a polymer obtained from 1,4-butanediol and a dicarboxylic acid selected from dodecanedioic acid and isophthalic acid containing 60 mol% or less of a dicarboxylic acid.

The polybutylene terephthalate or copolymer thereof according to the present invention uses 0-chlorophenol and needs to have an intrinsic viscosity of 0.5 or more when measured at 25°C. If the intrinsic viscosity is less than 0.5, it is difficult to obtain the desired blow moldability and impact resistance.

The α-olefin in the glycidyl group-containing copolymer comprising an α-olefin and a glycidyl ester of an α,β-unsaturated acid used in the present invention includes ethylene, propyleno, buteno-1, etc., and ethylene is preferably used.

Glycidyl ester group of α,β-unsaturated acid C. General formula (wherein R is a hydrogen atom, a lower alkyl group, or a lower alkyl group substituted with a glycidyl ester group).
Examples of the compounds include glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycyrel itaconate, among which glycidyl methacrylate is preferably used.

The amount of α,e-unsaturated acid copolymerized in the glycidyl group-containing copolymer is suitably in the range of 1 to 50%, particularly 2 to 30%. In addition, if the amount is 40% by weight or less, unsaturated monomers copolymerizable with the above copolymers, such as vinyl ethers, vinyl esters such as vinyl acetate and vinyl propionate, and acrylic acids such as methyl, ethyl, propyl, butyl, etc. and nuccrylic acid esters,
One or more types of acrylonitrile, styrene, carbon oxide, etc. may be copolymerized.

Preferred examples of the glycidyl group-containing copolymer in the present invention include ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer, ethylene/carbon oxide/glycidyl methacrylate copolymer, and ethylene/glycidyl methacrylate copolymer. /glycidyl acrylate copolymer,
Examples include ethylene/glycidyl acrylate/vinyl acetate copolymer.

The amount of the glycidyl group-containing copolymer mixed in the present invention is 3 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the saturated polyester. If the mixing amount is less than 3 parts by weight, it is difficult to obtain stable blow moldability and the impact resistance of the molded product is not sufficiently improved, and if it is more than 50 parts by weight, the mechanical properties of the saturated polyester tend to be impaired.
In addition, the moldability, especially the surface appearance, deteriorates, which are both unfavorable.

The glass fiber used in the present invention has a diameter of 3 to 20μ, particularly preferably 5 to 15μ, and a length of 500 to 7,00μ.
0μ, particularly preferably 1,000 to 5,000μ. Additionally, the surface may be treated with epoxy resin, vinyl acetate resin, or the like. The glass fibers in the molded product have an average diameter of 3 to 20 μm and an average length of 50 to 70 rh, and if the molded product is within this range, the blow moldability will be even better.
It was found that it has both impact resistance and high rigidity. The mixing ratio of glass fiber is 3 to 80 parts by weight, preferably 5 to 60 parts by weight, based on 100 parts by weight of the glass-unmixed polybutylene terephthalate resin composition.

If the mixing ratio of glass fibers is less than 3 parts by weight, high rigidity cannot be obtained, and if it is more than 80 parts by weight, blow moldability, especially formability, deteriorates, which is not preferable.

Note that antioxidants and heat stabilizers (including, for example, hindered phenols, hydroquinones, thioethers, phosphites, substituted products thereof, and combinations thereof) may be added to the composition of the present invention to the extent that the objects of the present invention are not impaired. ,
Addition of one or more UV absorbers (e.g. various resorcinols, salicylates, benzotriazoles, benzophenones, etc.), lubricants, mold release agents, colorants, flame retardants, antistatic agents, crystallization promoters, and other conventional additives. can do.

The blow molded article of the present invention is obtained by a known blow molding method. That is, the above-mentioned three types of mixed composition is melt-molded as a so-called parison, and then gas is blown into the obtained parison to obtain the desired hollow molded product. Therefore, the term "hollow molded product" as referred to in the present invention means any hollow molded product obtained by forming a parison and then expanding it with gas, and conformally includes a tank container, a pipe, etc.

〔Effect of the invention〕

The blow hollow molded article of the present invention has the following characteristics. In other words, by using a specific composition, the drawdown of the molten polymer discharged from the die is reduced, the shape of the molten parison is sufficiently maintained, and the dimensions and wall thickness of the molded product are made uniform. The result is a hollow container with less unevenness in thickness, good impact resistance, and high rigidity.

EXAMPLES Hereinafter, the manufacturing method and characteristics of the molded article of the present invention will be specifically illustrated with reference to Examples.

Examples 1 to 7, Comparative Examples 1 to 4 100 parts by weight of polybutylene terephthalate having an intrinsic viscosity of 1.7 was triblended with glass fiber and a glycidyl group-containing copolymer of the type and proportion shown in the table.
The mixture was melt-mixed and pelletized using an extruder set at .degree.

Using the obtained pellets, the outer diameter was 1001 mm at 250°C using a blow molding machine having an extruder with a diameter of 40 IljIφ.
1. A parison with a wall thickness of 3 fl was formed, and a regular square prism-shaped container with a side of 90 mm and a height of 500 mm was formed.

The moldability and impact resistance evaluation results of the molded products are shown in the table.

In addition, to judge the quality of moldability, the thickness of the upper 8 places of the body of the molded product is measured for 5 molded products, and the difference R between the upper thickness average value and the lower thickness average value is yy or less, it is good. Anything larger was judged to be defective. In the table, ◯ indicates good quality, and X indicates poor quality.

The impact resistance evaluation method is as follows:
A right circular cone with a load of 0.8 Ag was dropped from a height of 501 at room temperature, and the occurrence ratio of the amount of fracture was determined using n number 10. The rigidity was evaluated by punching the body into a test piece with a width of 12.5B and a length of 128 ff, and using ASTIVI-D7.
The flexural modulus was measured according to the 90 method.

Claims (1)

[Scope of Claims] (A) 100 parts by weight of polybutylene terephthalate or copolymer thereof having an intrinsic viscosity of 0.5 or more, (B) Copolymer of α-olefin and glycidyl ester of α,β-unsaturated acid A polybutylene terephthalate blow molded article obtained by blow molding a resin composition comprising 3 to 50 parts by weight of (C) glass fiber and 3 to 80 parts by weight of glass fiber.