JP2001049095A - Thermoplastic polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve water-resistance and mechanical strength by compounding a textile-reinforcing agent to a polybutylene terephthalate copolymer containing a specific copolymer component. SOLUTION: A polyester resin having 50 milli-equivalent concentration of a carboxyl terminal group/not more than 1 kg of polymer and 0.36-1.60 of viscosity (as o-chlorophenol solution at 25 deg.C) is obtained by mixing an aromatic dicarboxylic acid except terephthalic acid, an aromatic diol, a polybutylene terephthalate copolymer containing one or more copolymer components selected from alkylene oxide adducts in which the content of the copolymer components interms of mol% (A) is in a range of satisfying simultaneously equation 1<=A<=30 and 0.3B-7<=A<=0.5B+10, and polybutylene terephthalate if necessary. To 100 pts.wt. of this polyester resin, 10-100 pts.wt. of a textile-reinforcing agent is compounded. In the formula, B is the content (pts.wt.) of the textile- reinforcing agent per 100 pts.wt. of the polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has excellent water resistance under various conditions. For example, electric parts such as motors, etc., which require water resistance, automobile parts, machine parts, and resins used by being embedded in cement. The present invention relates to a thermoplastic polyester resin composition useful for applications such as a joining jig.

[0002]

2. Description of the Related Art Thermoplastic polyester resins typified by polyethylene terephthalate and polybutylene terephthalate reinforced with a fibrous reinforcing material are suitable as engineering plastics such as excellent heat resistance, moldability, chemical resistance and electrical insulation. Because of its unique properties,
It is mainly used for injection molding, and is used for various electric parts, mechanical parts, automotive parts, etc.

However, the strength of a polyester resin is apt to decrease in an aqueous atmosphere under various conditions, and its improvement has been a subject.

[0004] In metal insert parts such as motor insulators, welds are easily formed, and after molding or use, shrinkage causes minute voids between the metal and the resin, thereby causing moisture to penetrate therethrough, causing a decrease in strength. There was a problem.

As a conventional polyester resin composition, JP-A-1-147555 discloses an example in which a glass fiber and an elastomer are added to a polybutylene terephthalate resin.

[0006]

However, although the above polyester resin composition has improved impact strength, it has little effect on water resistance.

Accordingly, an object of the present invention is to provide a polyester resin composition satisfying excellent water resistance and mechanical strength.

[0008]

In order to achieve the above object, the present invention comprises the following inventions. 1. Containing at least one selected from the group consisting of aromatic dicarboxylic acids other than terephthalic acid, aromatic diols and their alkylene oxide adducts, and having a carboxyl end group concentration of 50 meq or less per kg of polymer A resin composition comprising 10 to 100 parts by weight of a polybutylene terephthalate-based copolymer and a fibrous reinforcing material with respect to 100 parts by weight of the polybutylene terephthalate-based copolymer, and A thermoplastic polyester resin composition, wherein the component content A (mol%) is within a range that satisfies the following formulas (1) and (2) simultaneously. 1 ≦ A ≦ 30 (1) 0.3B−7 ≦ A ≦ 0.5B + 10 (2) (where B is the amount of the fibrous reinforcing material relative to 100 parts by weight of the polybutylene terephthalate copolymer) It is the amount (parts by weight).) 2. An aromatic dicarboxylic acid other than terephthalic acid, an aromatic diol, and a polybutylene terephthalate-based copolymer and a polybutylene terephthalate containing at least one selected from the group of an alkylene oxide adduct thereof as a copolymer component, A resin composition comprising a polyester resin having a carboxyl end group concentration of 50 milliequivalents or less per 1 kg of a polymer and a fibrous reinforcing material in an amount of 10 to 100 parts by weight based on 100 parts by weight of the polyester resin, and , Content A of the above copolymer component (mol%)
Is a range that simultaneously satisfies the following relational expressions (1) and (2). 1 ≦ A ≦ 30 (1) 0.3B−7 ≦ A ≦ 0.5B + 10 (2) (where B is a polyester resin 100
The amount (parts by weight) of the fibrous reinforcing material relative to parts by weight. ) 3. The copolymerization component is isophthalic acid, phthalic acid,
3. The thermoplastic polyester resin composition according to the above 1 or 2, which is at least one selected from the group consisting of 2,6-naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, bisphenol A, bisphenol S, and an alkylene oxide adduct thereof. 4. 4. The thermoplastic polyester resin composition according to the above 1, 2, or 3, further comprising 0.1 to 50 parts by weight of an elastomer based on 100 parts by weight of the polyester resin. 5. 5. The thermoplastic polyester resin composition according to any one of the above items 1 to 4, wherein the fibrous reinforcing material is glass fiber and / or wollastenite. 6. An elastomer is obtained by converting ethylene into α having 3 or more carbon atoms.
6. The thermoplastic polyester resin composition according to the above item 4 or 5, which is an ethylene copolymer obtained by copolymerizing at least one of an olefin, an α, β unsaturated acid and an alkyl ester thereof.

As described above, according to the present invention, the polybutylene terephthalate resin contains a specific component in a specific amount as a copolymer component, which is unique to the improvement of water resistance when a fibrous reinforcing material such as glass fiber is used in combination. It is based on a new finding that the water resistance is effectively improved and the water resistance can be improved without impairing the mechanical strength.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The polybutylene terephthalate-based copolymer used in the present invention comprises an ester composed of terephthalic acid and 1,4-butanediol as a main polymerization component,
And an aromatic dicarboxylic acid other than terephthalic acid (hereinafter, referred to as copolymerized dicarboxylic acid) such as isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, or cyclohexanedicarboxylic acid as a dicarboxylic acid component, and / or
Alternatively, a copolymer polyester containing, as a copolymer component, at least one selected from aromatic diols such as bisphenol A, bisphenol S, and alkylene oxide adducts thereof (hereinafter, referred to as copolymerized diol) as a diol component. is there. Here, the copolymerization of only the above copolymerized dicarboxylic acid component, the copolymerization of only the above copolymerized diol component, or the copolymer obtained by copolymerizing both components may be used.

The content A (mol%) of the copolymer component is the ratio (mol%) of the copolymer dicarboxylic acid component to all dicarboxylic acid components and the ratio (mol%) of the copolymer diol component to all diol components. In the case where both of the copolymer components are contained, they are represented by their sum.

The content A (mol%) of the copolymer component is
It must be within a range that satisfies the following equations (1) and (2) simultaneously. Preferably, it is within a range that satisfies the following expressions (1 ′) and (2) simultaneously. 1 ≦ A ≦ 30 (1) 5 ≦ A ≦ 20 (1 ′) 0.3B-7 ≦ A ≦ 0.5B + 10 (2) (where B is the polyester resin 100
The amount (parts by weight) of the fibrous reinforcing material relative to parts by weight. When the content A of the copolymer component is less than the above range, the effect of improving the strength under a desired aqueous atmosphere is small,
If the amount is larger than the above range, the moldability will be remarkably deteriorated. As described above, in the present invention, in order to exhibit a desired effect, it is necessary to set the content A of the copolymer component to an optimum amount according to the blending amount B of the fibrous reinforcing material.

The polybutylene terephthalate copolymer is used in a blend of two or more copolymers as long as the content of the co-polymer component in the entire polyester resin is within the range of the present invention. Or a blend of a mixture of polybutylene terephthalate-based copolymer and polybutylene terephthalate (homopolymer).

In this case, the content A of the copolymer component in the polyester resin after blending is the ratio (mol%) of the copolymer dicarboxylic acid component to the total dicarboxylic acid component, and the ratio of the copolymer diol component to the total diol component. (Mol%), and when both copolymerization components are included, the sum thereof.

The carboxyl terminal group concentration of the polybutylene terephthalate-based copolymer or the polyester resin obtained by blending the same must be not more than 50 milliequivalents per kg of the polymer, and not more than 40 milliequivalents. More preferred. If it exceeds 50 meq, the water resistance becomes poor. Further, the carboxyl terminal group concentration mentioned here can be measured by performing a neutralization titration using an orthocresol / chloroform solvent and a sodium hydroxide / ethanol solution.

The viscosity of the polybutylene terephthalate copolymer or the polyester resin obtained by blending the same is not particularly limited as long as melt kneading is possible.
Those having an intrinsic viscosity of 0.36 to 1.60, particularly 0.52 to 1.35 when the chlorophenol solution is measured at 25 ° C., are preferable from the viewpoint of mechanical properties and moldability, In particular, 0.60 to 1.10 is more preferable. If the intrinsic viscosity is less than 0.36, the mechanical properties are poor, and if the intrinsic viscosity exceeds 1.60, the moldability becomes poor, and both are not preferred.

The fibrous reinforcing material used in the present invention includes glass fiber, wollastenite, potassium titanate whisker, zinc oxide whisker, carbon fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone fiber, metal Fiber and the like, glass fiber as a preferred example,
Wallacenite.

For the purpose of improving the dimensional stability of the molded product, zeolite, sericite, kaolin, mica,
Silicates such as clay, bentonite, asbestos, talc, alumina silicate, etc., metal compounds such as alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, iron oxide, carbonates such as calcium carbonate, magnesium carbonate, dolomite, and sulfuric acid It is also possible to use calcium, sulfate such as barium sulfate, glass beads, ceramic beads, boron nitride, silicon carbide and silica in combination.

Further, it is more preferable to use these fibrous and non-fibrous fillers after pre-treating them with a coupling agent such as a silane-based or titanate-based filler in terms of mechanical strength and the like.

The amount of the fibrous reinforcing material used in the present invention is as follows:
It is in the range of 10 to 100 parts by weight based on 100 parts by weight of the polyester resin, and preferably in the range of 15 to 70 parts by weight in view of the balance between fluidity and mechanical strength.

In the present invention, the water resistance can be further improved by further blending an elastomer. The elastomer used here is an olefin-based elastomer,
Butadiene-based, polyester-based, polyamide-based, and silicone-based elastomers.

Preferred are olefin elastomers. Among them, ethylene copolymers obtained by copolymerizing ethylene with any of α-olefins having 3 or more carbon atoms, α, β unsaturated acids and alkyl esters thereof. Coalescing is particularly preferred. Specific examples thereof include polyethylene / propylene copolymer, polyethylene / 1-butene copolymer, polyethylene / pentene copolymer, polyethylene / octene copolymer, polyethylene / (meth) acrylate copolymer, polyethylene / methyl ( Examples thereof include a (meth) acrylate copolymer, a polyethylene / ethyl (meth) acrylate copolymer, and a polyethylene / butyl (meth) acrylate copolymer. These elastomers may be used alone or in combination of two or more.

It is preferable to modify these olefinic elastomers with unsaturated carboxylic acids or unsaturated carboxylic acid glycidyl esters by copolymerization, grafting or the like, in order to improve the dispersibility of the elastomers. In particular, an olefin elastomer obtained by copolymerizing glycidyl (meth) acrylate is preferable.

The amount of the elastomer compounded is not particularly limited, but is preferably 100% polyester resin.
It is in the range of 0.1 to 50 parts by weight, more preferably 5 to 30 parts by weight based on parts by weight. If the amount of the elastomer exceeds 50 parts by weight, the moldability deteriorates, which is not preferable.

The thermoplastic polyester resin composition of the present invention contains a releasing agent, an antioxidant, a heat stabilizer, a lubricant, a crystal nucleating agent, an ultraviolet absorber, as long as the effects of the present invention are not impaired. Conventional additives such as colorants, flame retardants and small amounts of other polymers can be added. Examples of the release agent include montanic acid waxes, or metal soaps such as lithium stearate and aluminum stearate, higher fatty acid amides such as ethylenebisstearylamide, and ethylenediamine / stearic acid / sebacic acid polycondensate. it can. Examples of the crystal nucleating agent include polyether ether ketone resin and talc. Examples of the flame retardant include known organic halogen compounds, antimony compounds, inorganic phosphorus compounds such as red phosphorus, organic phosphorus compounds such as phosphate esters, and combinations thereof.

The method for producing the thermoplastic polyester resin composition of the present invention is not particularly limited, but the mixture of the raw materials is mixed with a conventional melt mixer such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader and a mixing roll. A typical example is a method of supplying and melting and kneading at a temperature of 200 to 350 ° C. The order of mixing the raw materials is not particularly limited. In addition, as for the small amount additive component, other components can be added before kneading after kneading and pelletizing other components by the above-described method or the like.

The resin composition of the present invention is formed into a desired shape by a general thermoplastic resin molding method such as injection molding, extrusion molding, blow molding, transfer molding, and vacuum molding. Is preferred.

[0028]

The present invention will be described in more detail with reference to the following examples. Reference Example 1 Polymerization Method of Polybutylene Terephthalate Copolymerization A-1 Polymerization 425 parts of terephthalic acid (TPA), isophthalic acid (IP
A) 75 parts [TPA / IPA = 85/15 mol%]
407 parts of 1,4-butanediol and 1 part of tetra-n-butyl titanate were charged into a reactor equipped with a rectification column, and 500 m
Under a reduced pressure of mHg, the temperature was gradually raised from 180 ° C. to 230 to cause a reaction to reach an esterification reaction rate of 95% or more. Then, the temperature was raised to 240 ° C. and 0.5 mmHg, and the pressure was reduced. Completed. The intrinsic viscosity of the obtained copolymer was 0.80 dl / g, and the carboxyl end group concentration was 35 meq / kg of the polymer.

Polymerization of A-2 325 parts of terephthalic acid (TPA) and 175 parts of isophthalic acid (IPA) [TPA / IPA = 65/35]
mol%], except that the polymerization was carried out in the same manner as in A-1. The intrinsic viscosity of the copolymer is 0.81 dl /
g, carboxyl end group concentration is 36 per kg of polymer
It was a milliequivalent.

Polymerization of A-3 The charge amounts were 425 parts of terephthalic acid (TPA) and 117 parts of dodecadionic acid (DDA) [TPA / DDA = 85/1.
5 mol%], except that the polymerization was carried out in the same manner as in A-1. The intrinsic viscosity of the copolymer is 0.80 dl /
g, carboxyl end group concentration is 34 per kg of polymer.
It was a milliequivalent.

The materials used in Examples and Comparative Examples are shown below. A-0: Homopolybutylene terephthalate resin Intrinsic viscosity 0.81 dl / g A-1: Polybutylene terephthalate / isophthalate copolymer (terephthalic acid / isophthalic acid: 85/15 m)
A-2: Polybutylene terephthalate / isophthalate copolymer (terephthalic acid / isophthalic acid: 65/35 m)
A-3: polybutylene terephthalate / dodecadicarboxylate copolymer (terephthalic acid / dodecadionic acid:
B-1: Glass fiber (chopped strand having an average fiber diameter of 10 μm) B-2: Fused silica (average particle diameter of 7 μm) C-1: Ethylene / methyl acrylate / glycidyl methacrylate copolymer (64/30 / 6 wt%).

The water resistance and tensile strength evaluated in Examples and Comparative Examples were evaluated and measured according to the following methods. (1) Evaluation of water resistance AST with gates at both ends and weld at the center
M1 type weld test piece with cylinder temperature 2
It was molded under the conditions of 60 ° C. and a mold temperature of 80 ° C. and used as a sample.
After the test piece was immersed in an aqueous liquid under predetermined conditions for a predetermined time, the tensile strength was determined in accordance with ASTM D638, and the strength retention of the processed product with respect to the unprocessed product was used as an index of water resistance.

(2) Evaluation of Tensile Strength An ASTM No. 1 test piece was molded under the conditions of a cylinder temperature of 260 ° C. and a mold temperature of 80 ° C. and used as a sample. ASTM
The tensile strength was determined according to D638.

(3) Evaluation of Moldability When molding the above weld test piece, the weld part was bent when the molded product was protruded and the test piece was deformed.

Examples 1 to 6 Screw diameter 57 mm set at a cylinder temperature of 250 ° C.
The polyester resin shown in Table 1 is supplied to the twin screw extruder of φ from the filling section, the reinforcing material is supplied from the side feeder, melt-kneaded, and the strand discharged from the die is passed through a cooling bath and passed through a strand cutter. And pelletized. Thus, as shown in Table 1, a composition in which the polybutylene terephthalate (co) polymer and the glass fiber were blended was obtained. When this composition was evaluated, as shown in Table 1,
All had high water resistance and tensile strength, and also had good moldability.

Example 7 47.6 parts by weight of glass fiber and 11.1 of elastomer
The polybutylene terephthalate copolymer containing 15 parts by weight of isophthalic acid was prepared and evaluated in the same manner as in Example 1 to evaluate the water resistance as shown in Table 1.
It had tensile strength and good moldability.

[0037]

[Table 1] Comparative Examples 1 and 2 Homopolybutylene containing 42.9 parts by weight of polybutylene terephthalate containing no copolymerization component and homopolybutylene terephthalate containing no glass fiber (Comparative Example 1) and silica as a non-fibrous reinforcing material. As a result of producing and evaluating a composition containing terephthalate (Comparative Example 2) in the same manner as in Example 1, as shown in Table 2, although the water resistance was good, the one having low tensile strength and being usable for the purpose of the present invention was not found. Did not.

Comparative Example 3 A composition containing 42.9 parts by weight of glass fiber and homopolybutylene terephthalate containing no copolymerization component was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2. As described above, the water resistance was low.

Comparative Examples 4 and 5 As shown in Table 2, 42.9 or 8
A polybutylene terephthalate copolymer composition containing 1.8 parts by weight and containing isophthalic acid in an amount of 5 or 15 mol%, which is smaller than the range of the present invention, was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2. Thus, the water resistance was not satisfactory.

Comparative Examples 6 and 7 As shown in Table 2, glass fibers were used at 17.6 or 4 respectively.
A polybutylene terephthalate copolymer composition containing 2.9 parts by weight and containing isophthalic acid in an amount of 25 or 35 mol%, which is more than the range of the present invention, was produced and evaluated in the same manner as in Example 1. The results are shown in Table 2. As described above, the test pieces could not be collected because of poor moldability.

Comparative Example 8 15 mol% of dodecadionic acid was used instead of isophthalic acid.
Except for using the copolymerized polybutylene terephthalate copolymer, a resin composition containing glass fibers was produced and evaluated in the same manner as in Example 4, and as a result, as shown in Table 2, water resistance was not satisfactory. Did not.

Comparative Example 9 Except for using homopolybutylene terephthalate,
As a result of producing and evaluating a resin composition containing glass fiber and an elastomer in the same manner as in Example 7, as shown in Table 2, water resistance was not satisfactory.

[0043]

[Table 2]

[0044]

Industrial Applicability The thermoplastic polyester resin composition of the present invention is a resin composition having excellent strength retention under various aqueous atmospheres, and also has excellent adhesion between resin and metal in metal insert parts. Great effect.

[0045] Therefore, it can be preferably used for electric parts such as motors and transformers, mechanical parts, connectors, automobile parts, construction parts for resin parts and the like which are used in contact with cement.

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Claims (6)

[Claims] An aromatic dicarboxylic acid other than terephthalic acid,
A polybutylene terephthalate copolymer containing at least one selected from the group consisting of an aromatic diol and an alkylene oxide adduct thereof as a copolymer component, and having a carboxyl end group concentration of 50 meq or less per 1 kg of the polymer; A resin composition obtained by blending a fibrous reinforcing material in an amount of 10 to 100 parts by weight with respect to 100 parts by weight of a polybutylene terephthalate copolymer, and a content A (mol%) of the copolymer component Is within a range that satisfies the following formulas (1) and (2) at the same time. 1 ≦ A ≦ 30 (1) 0.3B−7 ≦ A ≦ 0.5B + 10 (2) (where B is the amount of the fibrous reinforcing material relative to 100 parts by weight of the polybutylene terephthalate copolymer) It is the amount (parts by weight).) 2. An aromatic dicarboxylic acid other than terephthalic acid,
An aromatic diol and a polybutylene terephthalate-based copolymer containing at least one selected from the group of an alkylene oxide adduct thereof as a copolymer component, and a polybutylene terephthalate having a carboxyl end group concentration of 1 kg of the polymer The fibrous reinforcing material is added to the polyester resin 1
A resin composition in which 10 to 100 parts by weight is blended with respect to 00 parts by weight, and the content A (mol%) of the copolymer component satisfies the following relational expressions (1) and (2) simultaneously. A thermoplastic polyester resin composition characterized by being within the range. 1 ≦ A ≦ 30 (1) 0.3B−7 ≦ A ≦ 0.5B + 10 (2) (where B is a polyester resin 100
The amount (parts by weight) of the fibrous reinforcing material relative to parts by weight. ) 3. The method of claim 1, wherein said copolymer component is isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, bisphenol A, bisphenol S,
3. The thermoplastic polyester resin composition according to claim 1, which is at least one selected from the group consisting of these alkylene oxide adducts. 4. An elastomer comprising a polyester resin 1
The thermoplastic polyester resin composition according to claim 1, 2 or 3, which is added in an amount of 0.1 to 50 parts by weight based on 00 parts by weight. 5. The thermoplastic polyester resin composition according to claim 1, wherein the fibrous reinforcing material is glass fiber and / or wollastenite. 6. An ethylene-based copolymer obtained by copolymerizing ethylene with at least one of an α-olefin having 3 or more carbon atoms, an α, β unsaturated acid and an alkyl ester thereof. Item 6. The thermoplastic polyester resin composition according to item 4 or 5.