JPS61203163A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. having excellent moldability and resistance to heat and impact, consisting of a polybutylene terephthalate resin, glass fiber, a polyester elastomer and Na or K salt of a specified copolymer. CONSTITUTION:30-87wt% polybutylene terephthalate resin having an intrinsic viscosity of 0.4-2.5, composed of a dicarboxylic acid component contg. at least 40mol% of terephthalic acid and a diol component contg. at least 40mol% of 1,4-butanediol, or polyethylene terephthalate resin having an intrinsic viscosity of 0.4-1.4, 5-60wt% glass fiber such as chopped strand having a length of 0.4-6mm, 5-30wt% polyester elastomer which is an arom. polyester/ polyalkylene glycol block copolymer contg. at least 20wt% polyalkylene glycol having an MW of 650 or above and having a glass transition temp. of 10 deg.C or below and an MW of 10,000 or above, and 3-20wt% Na or K salt of an olefin/(meth)acrylic acid copolymer, are blended together.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyester resin composition, and more particularly to a glass fiber reinforced polyester resin composition with significantly improved impact resistance.

[Conventional technology]

-a Glass fiber reinforced materials of polybutylene terephthalate resin or polyethylene terephthalate resin have excellent properties such as heat resistance, chemical resistance, mechanical properties, and electrical properties, and are used in various OA equipment, connectors in the electronic field, coil bobbins, etc. Used in CRT sockets, etc.

By the way, for example, as with the above-mentioned connector, there are problems with impact resistance, such as cracks occurring when the terminals are press-fitted into the molded product, and the collar breaking during winding onto the coil bobbin.

[Problem that the invention seeks to solve]

Therefore, it is possible to improve this by blending various other polymers, but in order to sufficiently improve the impact resistance, it is necessary to blend a large amount of polycarbonate or polyester elastomer, etc. Resins have drawbacks such as poor moldability and a significant drop in heat deformation temperature.

It is an object of the present invention to provide a polyester resin composition that has significantly improved impact resistance without impairing such deterioration in moldability or high heat distortion temperature.

[Means for solving problems]

As a result of intensive studies to eliminate the above-mentioned drawbacks, the inventors have found that when reinforcing the polybutylene terephthalate resin or polyethylene terephthalate resin with glass fibers, a copolymer of polyester elastomer, olefin, acrylic acid or methacrylic acid, etc. It was discovered that by simultaneously blending a sodium salt or a potassium salt (ionomer), the impact resistance can be greatly improved with a relatively small blend amount without impairing the heat resistance, and in order to complete the present invention. It has arrived.

That is, the present invention comprises (A) 30 to 87% by weight of either polybutylene terephthalate resin or polyethylene terephthalate resin (B) 5 to 60% by weight of glass fiber (C) 5 to 30% by weight of polyester elastic material ( D) Consists of 3 to 20% by weight of a sodium salt or potassium salt of a copolymer of olefin and acrylic acid or methacrylic acid, and the total amount of each component of the above (A) to (D) is 100% by weight.
A polyester resin composition characterized by:

The polybutylene terephthalate resin in component (A) used in the present invention refers to at least 40% of the dicarboxylic acid component.
dicarboxylic acid component whose mol% is terephthalic acid and 1.4
- A copolymer consisting of a diol component containing 40 mol% or more of butanediol.

The dicarboxylic acid components other than terephthalic acid include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as azelaic acid, sebacic acid, adipic acid, and dodecane dicarboxylic acid, aromatic dicarboxylic acids such as isophthalic acid and naphthalene dicarboxylic acid, or cyclohexane. Alicyclic dicarboxylic acids such as dicarboxylic acids may be used alone or in mixtures.

Also, the intrinsic viscosity of this polybutylene terephthalate [η]
It is desirable that [η
] is the value determined from the solution viscosity measured at 25°C in a phenol/tetrachloroethane-50150 (weight ratio) solvent.

In addition, the polyethylene terephthalate resin used in the present invention refers to a homopolymer of linear polyethylene terephthalate having ethylene terephthalate as a constituent unit; a copolymer of this unit component and other copolymerizable components; or a homopolymer of these This refers to mixed resins with copolymers, but is not particularly limited to these. Here, as components that can be copolymerized, conventionally known acid components and glycol components can be used, and specifically, For example, acid components such as phthalic acid, isophthalic acid, adipic acid, sebacic acid, naphthalene-1,4- or -2,6-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid; propylene glycol, butylene glycol, Pentyl glycol, cyclohexane dimetatool, 2.2-
Glycol components such as bis(4-hydroxyphenyl)propane; oxyacids such as p-oxybenzoic acid, p-hydroxybenzoic acid, and p-hydroxyethoxybenzoic acid. The resin can be obtained by a normal polymerization method such as polycondensation of terephthalic acid and ethylene glycol by transesterification or direct esterification, but in this case, the intrinsic viscosity [η] of the resin is set to 0. 4-1.4
It is preferable to set it within the range of . Here, as a method for obtaining a resin having a high intrinsic viscosity, it is also possible to obtain a resin having a relatively low intrinsic viscosity by a conventional solid phase polymerization method.

The blending ratio of these (^) components is in the range of 30 to 87% by weight in the resin composition composed of each component (^) to (D),
Particularly preferred is a range of 45 to 80% by weight. If it is less than the lower limit of 30% by weight, heat resistance and flow processability will deteriorate, and if it exceeds the upper limit of 87% by weight, it will not be possible to improve the impact resistance, which is the objective of the present invention.

Next, as the component (B) glass fiber used in the present invention, any type of glass fiber such as roving type or chopped strand type can be used, but chopped strand type is particularly preferred in terms of productivity. preferable. In addition, considering workability during mixing of the resin composition of the present invention, abrasion resistance in a molding machine, cutting during the molding process, etc., approximately 0.4 to 6 f.
It is preferable that glass fibers having a length of l are used during mixing so that the length in the final molded product is in the range of about 0.2 to 2 wM.Such glass fibers may be subjected to various treatments. Commercially available products can be used as they are, and there are no particular limitations on the mixing method.

It is recommended that glass fiber be blended in a range of 5 to 60% by weight in the total resin composition. The reinforcing effect of the fibers becomes insufficient.

The (C) component polyester elastomer used in the present invention refers to residual polyalkylene glycols such as polytetramethylene glycol, polyethylene glycol, polyethylene glycol/polypropylene glycol block copolymers, and polyhydric alcohol/alkylene oxide adducts. Polyethylene terephthalate, polybutylene terephthalate, polyethylene, terephthalate isophthalate, polyethylene paraoxybenzoate, polyethylene terephthalate adibate, polyethylene terephthalate sebacate, polyethylene naphthalate, polybutylene terephthalate adipate, polybutylene terephthalate isophthalate. , aromatic polyester/polyether elastic resins having hard segments such as aromatic polyester residues such as polybutylene terephthalate and ethylene terephthalate. The elastic resin uses polyalkylene glycol with a molecular weight of 650 or more, preferably 800 to 6,000, and has a polyalkylene glycol portion of 20% by weight or more, preferably 30 to 80% by weight, and usually has a glass transition temperature of 10. ℃ or less, preferably -15℃ to -60℃
°C, molecular weight is 10.000 or more, preferably 30.00
0 or more aromatic polyester/polyalkylene glycol block copolymer. The polyester elastic body accounts for 5 to 30% by weight, preferably 5 to 2% by weight of the total resin composition.
It is blended in a range of 0% by weight. If the amount is more than 30% by weight, the heat distortion temperature will be significantly lowered, and if it is less than 5% by weight, the effect of improving impact resistance will not be noticeable.

Furthermore, component (D) in the present invention is a sodium or potassium salt of a copolymer of an olefin and acrylic acid or methacrylic acid, and the olefin is usually 50% of the copolymer.
-98% by weight, preferably 80-98% by weight, and 30% or more of the total carboxylic acid residues are neutralized with sodium or potassium, and a particularly preferred substance is sodium ethylene/methacrylic acid copolymer. It's salt. The blending amount is 3 to 20% by weight, preferably 3 to 10% by weight of the total resin composition. When the blending amount is less than 20% by weight, the heat distortion temperature decreases significantly, the compatibility with the polybutylene terephthalate resin and the polyethylene terephthalate resin decreases, and the strength decreases. Further, if it is less than 3% by weight, the effect of improving impact resistance will not be noticeable.

The polyester resin composition of the present invention may contain fillers such as wollastonite, mica, glass foil, clay or kaolin, ultraviolet absorbers, antioxidants, heat deterioration preventive agents, etc. without departing from the purpose of the present invention. Various additives such as stabilizers, dyes and pigments, and matting agents can be added.

An example of preparing the polyester resin composition of the present invention as described above is as follows.

Polybutylene terephthalate or polyethylene terephthalate (^), a predetermined amount of glass fiber (B), a polyester elastomer (C), a sodium salt or potassium salt of a copolymer of olefin and acrylic acid or methacrylic acid (0
) are added and mixed in a suitable mixer such as a tumbler, and then fed to an extruder or the like for melt-kneading and extrusion to form pellets.

In the resin composition of the present invention, the component (C) and (0
) component together with glass fiber-reinforced polybutylene terephthalate resin or polyethylene terephthalate resin, and even if component (C) or component ([1)] is blended alone, there is no noticeable impact resistance improvement effect. It is not allowed.

(Example) The present invention will be explained in more detail by showing Examples and Comparative Examples below.

Examples 1 to 11 Components (C) and (D) and 3fi chopped strand glass fibers were blended into polybutylene terephthalate having [η] 1.0 in the proportions shown in Table 1 below, and
Mix uniformly in a mold blender for 5 minutes. Using a 65 mφ vented melt extruder, this mixture was heated at a temperature of 2.
The polyester resin composition of the present invention was obtained by extrusion and pelletization at 40°C to 250°C.

Using the above resin composition, 3 ounces, screw diameter 300
Using a φ screw set extrusion molding machine, the cylinder temperature is 2.
AS at 60℃, mold temperature 80℃, molding cycle 30 seconds
Izot specimen (178) described in TM Ri-256
inch thickness) and a notch-free eye shift sample (178 inch thickness) with no notch portion, and ASTM D-256
An impact test was conducted in accordance with .

Also under the same molding conditions 12.7 x 127 x 3
．． Two crane strip specimens were molded and AST gate D-648 (1/8
inch, 18.6 ktr/cd) was measured.

Comparative Examples 1 to 9 Compositions (Comparative Examples 1 to 9) were obtained in the same manner as in Example 1, except that the compositions and blending ratios shown in Table 1 were used.

Measurements similar to those in the Examples were carried out on similar specimens made from the obtained compositions, and the results are shown in Table 1.

However, among the components (C) in Table 1 above, (E): polybutylene terephthalate/polytetramethylene glycol block copolymer, polytetramethylene glycol molecular weight 2.000° butylene terephthalate: polyether-4: 1 mol (Tg = - 58°C, molecular weight 45,000) (F):
Polyethylene terephthalate/polytetramethylene glycol block copolymer, polytetramethylene glycol molecular weight 1.000° ethylene terephthalate: polyether-4: 1 mol (Tg = -34°C, molecular weight 40.QOO) Table 1 (D
) component, (G) ethylene/methacrylic acid copolymer (85/1
5) Neutralize 60% by weight with sodium (H) Ethylene/acrylic acid copolymer (85/1
5) Neutralization with potassium at a weight ratio of 65% Examples 12 to 18 Chopped strand glass fiber with a length of 3 fi in a polyethylene terephthalate homopolymer with [η) of 0.72 (this is abbreviated as GF in the following Table 2) and the above (C),
Component (D) was blended and homogenized in the proportions shown in Table 2. The obtained mixture was put into a vent-type melt extruder with a diameter of 65 mm, and extruded at a cylinder temperature of 260°C to 280°C,
Got a beret.

Using the obtained resin composition, a 3 oz.
℃, mold temperature 140℃, molding cycle 30 seconds AST
Eye shift specimen (178
inch thick) and a non-notched Izont specimen (178 inch thick) with no notch portion, and ASTM D~256
An impact test was conducted in accordance with .

Also under the same molding conditions 12.7 x 127 x 3
．． A 2-inch strip test piece was formed, and ASTF40-648 (
The heat distortion temperature was measured at 1/8 inch (264 psi).

Comparative Examples 10 to 14 Example 12 except for the composition and blending ratio shown in Table 2.
A composition was prepared in the same manner as above, and the same test was conducted on a similar specimen made of the obtained composition. These results are shown in Table 2.

However, among the components in Table 2 (C), (■): polybutylene terephthalate/polytetramethylene glycol block copolymer, polytetramethylene glycol molecular weight 2.000, butylene terephthalate: polyether; 4:1 molar ratio (Tg = - 58°C, molecular weight 45,000) (J):
Polyethylene terephthalate/polytetramethylene glycol block copolymer, polytetramethylene glycol molecular weight 1.000, ethylene terephthalate:polyether concentration 4:1 molar ratio (Tg = -34°C, molecular weight 40.000) (D ) In the ingredients, (to): ethylene/methacrylic acid copolymer (85/1
5 weight ratio) Neutralize 60% of methacrylic acid with sodium (L): Ethylene/acrylic acid copolymer (85/1
5 weight ratio) 65% of acrylic acid was neutralized with potassium.As is clear from the results in Tables 1 and 2 above, the above component (C)
It was clear that the impact resistance of the glass fiber reinforced polyester resin could be greatly improved by adding a relatively small amount of component (D).

〔Effect of the invention〕

As detailed above, the polyester resin composition according to the present invention can provide molded products with greatly improved impact resistance without substantially impairing their heat resistance, and is useful for industrial applications. The value is extremely great.

Claims (1)

[Claims] (A) Any one of polybutylene terephthalate resin or polyethylene terephthalate resin 30 to 87% by weight (B) Glass fiber 5 to 60% by weight (C) Polyester elastomer 5 to 30% by weight (D) Consists of 3 to 20% by weight of a sodium salt or potassium salt of a copolymer of olefin and acrylic acid or methacrylic acid, and the total amount of each component of the above (A) to (D) is 100% by weight. A polyester resin composition characterized by: