JPH06212050A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition excellent in dimensional accuracy, that is, hardly causing molding shrinkage. CONSTITUTION:This resin composition is obtained by blending (a) 98-40wt.% polybutylenenaphthalene dicarboxylate with (b) 2-60wt.% ABS resin and, as necessary, 2-15wt.% inorganic filter. This composition has good mechanical strength, heat resistance and dimensional stability as well as high dimensional accuracy.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent dimensional accuracy.

[0002]

2. Description of the Related Art Aromatic polyester compositions represented by polybutylene terephthalate (hereinafter abbreviated as PBT) are generally superior in mechanical strength, electrical insulation, chemical resistance, etc. -Widely used as electronic parts, home appliance lighting parts, automobile parts, mechanical parts, etc. Like other aromatic polyesters, polybutylene naphthalene dicarboxylate (hereinafter sometimes abbreviated as PBN) has excellent properties in mechanical strength, oxidation resistance, solvent resistance and the like. Since PBN is a crystalline resin like PBT and the like, it has a drawback that the dimensional change due to crystallization shrinkage of the resin at the time of molding or after molding is large, and therefore improvement thereof is required.

However, high performance of PBN,
Almost no studies on high performance have been made so far, and there are few academic documents or patent applications. Therefore, what kind of additive can be used to improve the properties, and the function-imparting agent and performance-improving agent used for other polyester resins are PB.
Little is known about whether or not it is applicable to N.

The present inventor has accomplished the present invention as a result of extensive studies aimed at improving the impact strength of PBN resin.

[0005]

An object of the present invention is to provide a new resin composition having excellent impact resistance.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention is a resin composition comprising (a) polybutylene naphthalene dicarboxylate and (b) ABS resin.

The present invention will be described in detail below. In the present invention, polybutylene naphthalene dicarboxylate is
Naphthalene dicarboxylic acid, preferably naphthalene-2
Polyester containing 6-dicarboxylic acid as a main acid component and 1,4-butanediol as a main glycol component,
That is, it is a polyester in which all or most of the repeating units (usually 90 mol% or more, preferably 95 mol% or more) are butylene naphthalene dicarboxylate.

Further, the following components can be copolymerized with this PBN as long as the physical properties are not impaired. That is, as the acid component, an aromatic dicarboxylic acid other than naphthalenedicarboxylic acid, for example, phthalic acid, isophthalic acid, terephthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylketonedicarboxylic acid, Diphenyl sulfide dicarboxylic acid, diphenyl sulfone dicarboxylic acid, aliphatic dicarboxylic acid such as succinic acid,
Examples thereof include adipic acid, sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, tetralindicarboxylic acid, decalindicarboxylic acid and the like.

As the glycol component, ethylene glycol, propylene glycol, trimethylene glycol,
Pentamethylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyethylene glycol,
Examples include bisphenol A, catechol, resorcinol, hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, dihydroxydiphenylmethane, dihydroxydiphenyl ketone, dihydroxydiphenyl sulfide, and dihydroxydiphenyl sulfone.

Examples of the oxycarboxylic acid component include oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid and ω-hydroxycaproic acid.

Further, a tri- or higher functional compound such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid or pyromellitic acid may be copolymerized within a range in which PBN does not substantially lose the molding performance.
Can be obtained by polycondensing naphthalenedicarboxylic acid and / or a functional derivative thereof and butylene glycol and / or a functional derivative thereof using a conventionally known aromatic polyester production method.

The ABS resin used in the present invention is obtained by graft-copolymerizing styrene and a vinyl monomer containing acrylonitrile as a main component in the presence of a diene polymer rubber obtained by polymerizing butadiene, styrene-butadiene and the like. Say something. The polymerization method of these graft copolymers belongs to radical polymerization, and any of emulsion polymerization, bulk polymerization and suspension polymerization may be used. ABS
The butadiene content in the resin is selected in the range of 15-40% by weight. When the butadiene content is less than 15% by weight, the impact strength of the resulting resin composition is significantly lowered,
If it exceeds 5% by weight, the rigidity, especially the flexural modulus decreases, which is not preferable.

In the present invention, the amount of ABS resin added is
It is 2 to 60 parts by weight with respect to 98 to 40 parts by weight of PBN. If the addition amount is less than 2 parts by weight, the improvement in dimensional accuracy, which is the object of the present invention, is not observed, and if it exceeds 60 parts by weight, the moldability is poor, which is not preferable.

The inorganic filler to be used in the present invention is a compound which is blended mainly for the purpose of obtaining a molded article excellent in performance such as mechanical strength, heat resistance, dimensional stability, and electrical properties. Fillers in the form of powder, granules or plates are used.

Examples of the fibrous filler include glass fiber, carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, boron fiber, boron nitride fiber, potassium titanate fiber, stainless steel, aluminum and titanium. Inorganic fibrous substances such as metallic fibrous substances such as copper, brass, and the like. Particularly representative fibrous fillers are glass fibers or carbon fibers.

Further, as the particulate filler, carbon black, silica, quartz powder, glass beads, glass powder,
Calcium silicate, kaolin, talc, clay, diatomaceous earth,
Silicates such as wollastonite, iron oxide, titanium oxide,
Examples thereof include oxides of metals such as zinc oxide and alumina, sulfates of metals such as calcium carbonate and barium carbonate, silicon carbide, silicon nitride, boron nitride, and various metal powders.

Examples of the plate-like filler include mica, glass flakes, various metal foils and the like.

These inorganic fillers can be used alone or in combination of two or more. The combined use of fibrous fillers, especially glass fibers and granular and / or plate-like fillers is a preferable combination because it has both mechanical strength, dimensional accuracy and electrical properties.

When using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. If this example is shown, an epoxy compound, a silane compound,
It is a functional compound such as an isocyanate compound, a silane compound, and a titanate compound. These compounds may be subjected to surface treatment or focusing treatment before use, or may be added at the same time when the materials are adjusted.

In the present invention, the addition amount of the inorganic filler is PB.
2 to 15 based on 100 parts by weight of N and ABS resin in total
0 parts by weight. If the amount is less than 2 parts by weight, the mechanical strength, heat resistance, dimensional stability and electrical properties are not improved, and if it exceeds 150 parts by weight, the dispersion is poor and extrusion and molding are difficult. There is no improvement in dimensional accuracy due to the addition of ABS resin.

A flame retardant may be added to the composition of the present invention to impart flame retardancy. Known flame retardants include brominated epoxy and brominated bisphenol A.
Type polycarbonate and the like. The brominated epoxy flame retardant has the following structure (I).

[0022]

[Chemical 1]

The brominated bisphenol A type polycarbonate flame retardant has the following structure (II). Although the terminal structure is not particularly limited, a structure (III) having a 4-tertbutylphenyl group, a structure (IV) having a 2,4,6-tribromophenyl group and the like are possible.

[0024]

[Chemical 2]

[0025]

[Chemical 3]

[0026]

[Chemical 4]

The amounts of these flame retardants added are PBN and A.
It is 3 to 30 parts by weight with respect to 100 parts by weight in total with the BS resin. If the amount added is less than 3 parts by weight, the flame retardant effect does not appear. If the amount added exceeds 30 parts by weight, the flame retardant is poorly dispersed, resulting in poor extrudability and moldability, and the strength of the resulting molded product. Is also low, which is not preferable.

In order to improve the flame retardancy of the composition of the present invention, Sb ₂ O ₃ or xNa ₂ O.Sb ₂ O ₅ .yH is used.
It is preferable to incorporate a flame retardant auxiliary agent such as ₂ O (x = 0 to 1, y = 0 to 4). The particle size is not particularly limited, but can be 0.
02 to 10 μm is preferable. If necessary, it may be surface-treated with an epoxy compound, a silane compound, an isocyanate compound, a silane compound, a titanate compound or the like. Addition amount of flame retardant aid is 1 for PBN and ABS resin in total
It is 0 to 20 parts by weight with respect to 00 parts by weight, but if the flame retardant aid is not added, it is necessary to add a large amount of the flame retardant, so 20 to 70 parts by weight of the flame retardant is preferable. It is better to add a combustion aid. The addition amount is PBN
When it is more than 20 parts by weight with respect to 100 parts by weight of ABS resin and ABS resin in total, the decomposition of the resin and the compounding agent is promoted, and the strength of the molded product is lowered, which is not preferable.

The resin composition of the present invention may contain various additives as long as the object of the present invention is not impaired.

As additives, phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, ultraviolet absorbers, release agents,
Examples include colorants.

The method for preparing the thermoplastic resin composition of the present invention is as follows: 1) a method in which the components are mixed, melt-kneaded by an extruder, and then pelletized. Examples include a method in which pellets having different compositions are once prepared, a predetermined amount of the pellets are mixed and subjected to molding, and a molded article having a target composition is obtained after molding, 3) a method in which each component is directly charged into a molding machine, and the like.

[0032]

EXAMPLES The present invention will be specifically described below with reference to examples.

The method of measuring the molding shrinkage ratio is as follows. A flat plate having a film gate is injection molded, and the shrinkage ratio is calculated from the mold size and the size of the actual molded product. The shrinkage rate of the resin in the flow direction (MD) and the shrinkage rate in the direction perpendicular to the flow (TD) are obtained.

The intrinsic viscosity of PBN was 35 ° C. using an Ostwald viscometer using orthochlorophenol as a solvent.
There is a value measured in.

The ABS resin and flame retardant used in the examples are as follows. ABS1: Emulsion polymerization of 25% by weight of acrylonitrile and 41% by weight of styrene in the presence of 34 parts by weight of polybutadiene. ABS2: Emulsion polymerized with 33% by weight of acrylonitrile and 48% by weight of styrene in the presence of 19% by weight of polybutadiene. Flame retardant 1: A brominated epoxy flame retardant having an average degree of polymerization of about 15. Flame retardant 2: Brominated bisphenol A type polycarbonate flame retardant having an average degree of polymerization of about 6.

[0036]

[Examples 1 to 6 and Comparative Examples 1 and 2] PBN (intrinsic viscosity 0.78) and the above ABS were uniformly mixed in advance at a ratio shown in Table 1, and then a test piece for measuring shrinkage was measured by an injection molding machine. Molded. The cylinder temperature during molding was 275 ° C, and the mold temperature was 120 ° C.

The molding shrinkage of the obtained test piece is shown in Table 1.
Shown in. Molding shrinkage (that is, improvement in dimensional accuracy) was observed by the addition of ABS.

[0038]

[Table 1]

[0039]

Examples 7 to 15 and Comparative Examples 3 to 6 PBN (intrinsic viscosity 0.78), ABS, glass fiber, flame retardant, and flame retardant aid (antimony trioxide or antimony pentoxide) in the proportions shown in Table 2. Was uniformly mixed in advance and then melt-kneaded with a twin-screw extruder having a diameter of 44 mm to obtain pellets for molding. The obtained pellets were molded into a test piece for measuring shrinkage with an injection molding machine. The resin temperature during molding was 275 ° C, and the mold temperature was 120 ° C. Table 2 shows the molding shrinkage of the obtained test piece.

It has been found that the dimensional accuracy is improved by the addition of ABS even if the resin composition contains an inorganic filler such as glass fiber, a flame retardant, or a flame retardant aid.

[0041]

[Table 2]

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location C08K 5/09 KJV 7242-4J 5/15 KJW 7242-4J C08L 63/00 NJN 8830-4J NJX 8830-4J 67 / 02 LPB 8933-4J 69/00 LPN 9363-4J

Claims (4)

[Claims] 1. (a) Polybutylene naphthalene dicarboxylate 98 to 40% by weight and (b) ABS resin 2
A thermoplastic resin composition consisting of -60 parts by weight. 2. The resin composition according to claim 1, which is 100% by weight.
A resin composition containing 2 to 150% by weight of an inorganic filler. 3. A resin composition comprising 100 parts by weight of the resin composition according to claim 1 and 3 to 30 parts by weight of a flame retardant and 0 to 20 parts by weight of a flame retardant auxiliary. 4. A resin comprising 100 parts by weight of the resin composition according to claim 1 and 2 to 150 parts by weight of an inorganic filler, 3 to 30 parts by weight of a flame retardant and 0 to 20 parts by weight of a flame retardant auxiliary. Composition.