JPH0715049B2 - Thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having improved properties, and more specifically to a thermoplastic polyester, a thermoplastic polyurethane and an alkyl acrylate or alkyl. The present invention relates to a resin composition comprising a polymer modifier containing methacrylates as a main component, which has good fluidity during molding, a good surface appearance, and a high impact strength, and which is suitable for various industrial materials.

“Prior art and its problems” Thermoplastic polyesters have been consumed in large amounts as fibers and films for a long time. Among them, polyalkylene terephthalate has excellent technical properties such as mechanical strength such as rigidity and hardness. In recent years, it has been used as a molding material in a wide range of fields such as electric and electronic device parts and automobile parts due to its heat resistance, electric characteristics, solvent resistance and rapid workability.

However, these polyalkylene terephthalates as engineering plastics have a drawback that the impact strength when notched is insufficient, and by improving them, they can be used for wider applications. Therefore, many attempts have been made to improve such drawbacks.

That is, an attempt is made to improve the impact strength by mixing a modified elastomer or the like with polyalkylene terephthalate, for example, polybutylene terephthalate is mixed with a usual ABS resin composed of a conjugated diolefin, styrene, and acrylonitrile (Japanese Patent Publication No. 47). -30421) is known.

By the way, ordinary ABS resin greatly improves the impact strength of vinyl polymers such as vinyl chloride resin and polystyrene, but it is not very effective as an impact modifier for non-vinyl polymers, and in fact, JP-B-47-30421. As seen in the official gazette, the impact strength of polybutylene terephthalate is hardly improved.

On the other hand, there is known a method of improving impact strength by blending polyalkylene terephthalate with acrylates or methacrylates. However, as seen in JP-A-49-82749, although the impact strength is improved,
Especially, it is not so good at low temperature such as -40 ℃. Further, in the experience of the inventor, when acrylates or methacrylates were blended with polyalkylene terephthalate, the fluidity was abnormally increased and the fluidity was deteriorated, and the thickness was 1 mm or less, further 0.5 mm or less. It is difficult to obtain a thin injection molded product.

Further, a method of blending polyalkylene terephthalate with thermoplastic polyurethane to improve impact strength is also known (Japanese Patent Publication No. 53-28946). However, since melt-kneading of polyalkylene terephthalate and thermoplastic polyurethane is originally difficult and the compatibility is poor, delamination phenomenon is observed in the obtained molded product, resulting in poor surface appearance. Also, because of that, its impact strength (especially at low temperatures)
Had a problem that it did not improve as expected.

"Means for Solving Problems" An object of the present invention is to obtain a resin composition which is modified with a thermoplastic polyester without lowering its molding fluidity, has a good surface appearance, and has a high impact strength. is there.

As a result of intensive studies, the inventors of the present invention surprisingly have excellent molding fluidity by mixing a thermoplastic polyester and a polymer having a thermoplastic polyurethane and alkyl acrylates or alkyl methacrylates as a main component, The inventors have found that a resin composition having a good surface appearance and excellent impact resistance can be obtained, and completed the present invention.

That is, the present invention is a thermoplastic resin composition comprising a thermoplastic polyester (A), a thermoplastic polyurethane (B), and a polymer (C) containing an alkyl (meth) acrylate as a main component.

The present invention is surprisingly superior to the two-component system of thermoplastic polyester / thermoplastic polyurethane or the two-component system of a polymer based on thermoplastic polyester / (meth) acrylates, particularly in its impact strength (especially at low temperature). ) Is high, the surface appearance is excellent, and the fluidity at the time of molding is excellent.

Thermoplastic polyester resin (A) suitable for the purpose of the present invention
Are the reaction products of aromatic dicarboxylic acids or their reactive derivatives such as dimethyl esters or anhydrides with aliphatic, cycloaliphatic or araliphatic diols or mixtures thereof. A preferable thermoplastic polyester resin can be produced from terephthalic acid or its reactive derivative and an aliphatic or cycloaliphatic diol containing 2 to 10 carbon atoms by a known method. Also, a preferred thermoplastic polyester resin is
At least 80 mol%, preferably at least 90 mol%, of terephthalic acid residues based on the dicarboxylic acid component and at least 80 mol%, preferably at least 90 mol% of ethylene glycol and / or 1, based on the diol component. Contains the residue of 4-butanediol.

In addition to the terephthalic acid residue, the thermoplastic polyester resin is used to provide up to 20 mol% of other aromatic dicarboxylic acids containing 8 to 14 carbon atoms or aliphatic dicarboxylic acids containing 4 to 12 carbon atoms. Acid residues, such as phthalic acid,
Isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4 '
It may contain residues of diphenyldicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid and cyclohexanediacetic acid.

In addition to the residues of ethylene glycol or 1,4-butanediol, thermoplastic polyester resins up to 20 mol%,
Residues of other aliphatic diols containing 3 to 12 carbon atoms or cycloaliphatic diols containing 6 to 21 carbon atoms, 1,3-propanediol, 2-ethyl-1,3- Propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexane-1,4-dimethanol, 3-methyl-2,4-pentanediol, 2-methyl-2,4-pentane Diol, 2,2,4-trimethyl-1,3-pentanediol, 2,2,4-trimethyl-1,6-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-1 1,3-Propanediol, 2,5-Hexanediol, 1,4-
Di- (β-hydroxyethoxy) -benzene, 2,2-bis- (4-hydroxycyclohexyl) -propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2-
It can contain residues of bis- (3-β-hydroxyethoxyphenyl) -propane and 2,2-bis- (4-hydroxypropoxyphenyl) -propane.

The thermoplastic polyester resin (A) can be branched by incorporating a relatively small amount of a trivalent or tetravalent alcohol or a tribasic or tetrabasic carboxylic acid. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane, trimethylolpropane and pentaerythritol. It is appropriate to use no more than 1 mol% of branching agent, based on the acid component.

Particularly preferred thermoplastic polyester resins (A) are terephthalic acid and its reactive derivatives, such as dialkyl esters, and polyalkylene terephthalates prepared exclusively from ethylene glycol and / or 1,4-butanediol, and / or their It is a mixture of polyalkylene terephthalates.

The thermoplastic polyester resin may also be a copolyester produced from at least two kinds of the above-mentioned acid component and / or at least two kinds of the above-mentioned alcohol component, and specifically, poly- (ethylene glycol / 1,4- Butanediol) -terephthalate.

On the other hand, as the thermoplastic polyurethane used in the present invention, all known thermoplastic polyurethanes can be used, but generally polyester polyols and polyamides having at least two or more active hydrogen atoms in one molecule. In principle, linear heat obtained by reacting one or a mixture of two or more low molecular weight polyols with a polyester polyol, a polycarbonate polyol, a polyether polyol, and a polyfunctional isocyanate in an equimolar ratio. It is a plastic polyurethane. More specifically, as a compound constituting the polyol having at least two active hydrogen atoms in at least one molecule,
(1) Polyester polyols or lactone polyester polyols comprising organic acids such as phthalic acid, adipic acid, maleic acid and the like and glycols such as ethylene, propylene and butylene or a small amount of triols such as trimethylolpropane and glycerin, or lactone polyesterpolyols thereof, if necessary. Mixture, (2) polyoxypropylene glycol, poly (oxypropylene) poly (oxyethylene) glycol,
Polyether polyol such as polyoxytetramethylene glycol or a mixture thereof, (3) Polycarbonate diol obtained by dephenolizing hexane glycol and diphenyl carbonate and (1) or (2), and (4) ethylene, propylene. , Glycol such as butylene, or a small amount of low molecular weight polyol such as triol, or a mixture thereof, if necessary. Furthermore, (1), (2), (3) or (1),
Mixtures of (2), (3) and (4) are also suitable. On the other hand, as the polyfunctional isocyanate as a raw material of the thermoplastic polyurethane, tolylene diisocyanate, tolylene diisocyanate dimer, diphenylmethane-4,
4'-diisocyanate, hydrogenated diphenylmethane-
Known diisocyanates such as 4,4'-diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate and cyclohexane diisocyanate are used.

Examples of the polymer (C) mainly containing alkyl acrylates or alkyl methacrylates used in the present invention include alkyl acrylates having 2 to 10 carbon atoms in the alkyl portion and 4 to 10 carbon atoms in the alkyl portion. Homopolymers of alkyl methacrylates having atoms, at least about 10 mole% of alkyl acrylates having 2 to 10 carbon atoms in the alkyl portion and alkyl methacrylates having 1 to 3 carbon atoms in the alkyl portion Copolymer with, alkyl acrylates having 2 to 10 carbon atoms in the alkyl part and 4 in the alkyl part
~ Copolymers with alkyl methacrylates having 10 carbon atoms, 4 in the methyl acrylate and alkyl moieties
Copolymers with at least about 10 mol% alkyl methacrylate having from 10 to 10 carbon atoms, 2 in the alkyl moiety
Copolymer of alkyl acrylates having 10 to 10 carbon atoms, copolymer of methyl acrylate and at least 10 mol% of alkyl acrylate having 2 to 10 carbon atoms in the alkyl moiety, 4 to 10 carbons Copolymers of alkyl methacrylates having atoms, alkyl methacrylates having 1 to 3 carbon atoms in the alkyl portion and at least about 10 mol% alkyl methacrylate having 4 to 10 carbon atoms in the alkyl portion Copolymers with the above-mentioned homo- or copolymers, and a comonomer selected from one or more kinds of butadiene, isoprene, ethylene, propylene, vinyl acetate, and styrene (provided that the co-monomer The monomer is 50 mol% of the monomer system
The following)) or a trunk polymer such as a rubber-based or acrylic elastomer mainly composed of a conjugated diolefin such as butadiene or isoprene, and grafted with the above-mentioned acrylates or methacrylates. The obtained graft copolymer etc. are mentioned.

In the present invention, the blending ratio of the (A) thermoplastic polyester, the (B) thermoplastic urethane, and the (C) alkyl acrylates or alkyl methacrylates as the main component of the polymer modifier is (A) + (B) + (C). In the composition of 100 parts by weight, (A) is 99 to 5 parts by weight, preferably 99 to 50 parts by weight, (B) is 0.9 to 94.9 parts by weight, preferably 0.9 to 49.9 parts by weight, (C). Is 0.1 to 30 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 0.1 to 4 parts by weight. If the compounding ratio is out of this range, fluidity,
A resin composition having satisfactory appearance and impact strength cannot be obtained.

Various reinforcing agents, fillers, crystal nucleating agents, pigments, dyes, plasticizers, flame retardants, release agents, etc. can be added to the resin composition of the present invention. For example, as the reinforcing agent and the filler, glass fiber, carbon fiber, potassium titanate fiber, metal fiber, ceramic fiber, aramid fiber, rock wool: calcium carbonate, calcium silicate, magnesium silicate, calcium sulfate, talc, clay, mica, Examples thereof include barium sulfate, iron oxide, graphite, carbon black, mica, asbestos, ceramics, metal flakes, glass beads, glass powder, and the like, and one or a mixture of two or more thereof may be used.

In particular, when glass fibers are used, various characteristics such as a great improvement in mechanical properties and heat resistance and a decrease in molding shrinkage are exhibited. However, such glass fibers are suitable binders and adhesion aids or vinylsilane-based, aminosilane-based , Those treated with a silane-based coupling agent such as epoxy silane-based may be used.
Glass, chopped strand glass or milled
It can be supplied in the form of glass or the like. Further, the diameter of the glass fiber as the reinforcing filler is in the range of 0.005 to 0.02 mm, its length is 0.01 to 10 mm, preferably 0.05 to 1 mm.
The range is appropriate. If the length of the glass fiber is too short, the reinforcing effect is not sufficient, and if it is too long, the surface finish of the molded product is poor and the moldability becomes poor.

The method for producing the resin composition of the present invention includes various commonly known methods such as a method of mixing using a high-viscosity resin reaction kettle, a kneader and an extruder, or a method of directly performing molding at the same time as mixing with an injection molding machine. Can be applied. For example, (A) thermoplastic polyester, (B) thermoplastic urethane and (C) polymer containing alkyl acrylates or alkyl methacrylates as main components, and if necessary, other additives are premixed with a ribbon blender or the like, and then the extruder is used. Then, it is melt-mixed and pelletized into a molding material.
Various methods are known for adding a reinforcing filler, but any known method is applicable and is not particularly limited by the manufacturing method.

The temperature at the time of preparing the mixture is higher than the melting point of the thermoplastic polyester and is 300 ° C or lower, preferably 230 ° C to 280 ° C.
It is what

The composition of the present invention includes injection molding, extrusion molding, blow molding,
The thermoplastic resin can be molded by any known molding method such as vacuum molding, and the molded product obtained by the present invention can be subjected to secondary processing such as painting, vapor deposition, and adhesion.

INDUSTRIAL APPLICABILITY The composition of the present invention is useful for various kinds of applications such as machine / apparatus parts, automobile interior / exterior parts, home electric appliances and electric / electronic equipment parts. Especially, because of its excellent impact resistance and heat resistance of hardness, various motors can be used. Type housing, gear pump case,
It is useful as an industrial material for distributor caps, lamp housings, coil hobbins, etc.

"Effects of the Invention" The resin composition of the present invention has excellent molding fluidity, excellent surface appearance of molded articles, and excellent impact resistance, and also has well-balanced performance in heat resistance, other mechanical properties, and the like. It is what

[Examples] The present invention will be further described with reference to Examples. The parts and% in the examples are by weight unless otherwise specified.

Reference Example 1 <Production of thermoplastic polyurethane> Epsilon-lactone polyester polyol having a hydroxyl equivalent of 1000
Keep 2000 parts and 360 parts of 1,4-butylene glycol at 80 ℃,
Diphenylmethane-4,4'-diisocyanate 1 at about 90 ℃
Add 275 parts with vigorous stirring. The reaction was rapidly exothermic and reached 140 ° C in about 1-2 minutes. When the temperature reaches 140 ° C, stop stirring and pour thermoplastic polyurethane into a sheet into a container preheated to 160 ° C.
Hold at 30 ° C for 30 minutes. After cooling, it was pelletized with a pelletizer.

Examples 1-5, Comparative Examples 1-3 Phenol / tetrachloroethane = 6/4 Polybutylene terephthalate (PBT) having an intrinsic viscosity [η] = 1.13 measured at 30 ° C. and the thermoplastic polyurethane obtained in Reference Example 1 and Copolymer powders of methyl methacrylate / butyl acrylate = 90/10 were mixed at the ratios shown in Table 1, and kneaded and extruded at 240 ° C. with a 40φ extruder equipped with a Dalmagee screw to form pellets. In addition, these pellets are inline screw type 3 ounce injection molding machine (made by Toshiba Machine)
A molded product was molded at a cylinder temperature of 240 ° C. and its physical properties were measured. The results are shown in Table 1. In addition, the same machine was used to measure the spiral flow length at a cylinder temperature of 240 ° C., and the results are also shown in Table 1.

As is clear from Table 1, the one according to the present invention has a remarkable improvement in impact strength as compared with the one only for PBT (Comparative Example 1).
Compared to the mixture of T and thermoplastic polyurethane (Comparative Example 2), there is no phase separation of PBT / thermoplastic urethane, so the appearance is good and the impact strength is high. It was excellent in fluidity, appearance, and impact strength as compared with Example 3).

Examples 6-11, Comparative Examples 4-5 Phenol / tetrachloroethane = 6/4 Polybutylene terephthalate (PBT) with an intrinsic viscosity [η] = 0.85 measured at 30 ° C. and Pandex TR-3080 (Dainippon Ink and Chemicals) Table-2 shows the polyester thermoplastic thermoplastic polyurethane manufactured by Kogyo Co., Ltd., Kane Ace PA-20 (acrylic rubber manufactured by Kanegafuchi Chemical Co., Ltd.), and epoxysilane-treated chopped glass fiber with a length of 6 mm. The mixture was mixed at a ratio, and the mixture was kneaded and extruded at 250 ° C. with a 40 mmφ extruder equipped with a dullage screw to obtain pellets. Further, these pellets were molded with a 3 ounce injection molding machine at a cylinder temperature of 240 ° C., and the physical properties thereof were measured. The results are shown in Table 2. Moreover, the spiral flow length at a cylinder temperature of 250 ° C. was measured by the same molding machine, and the results are shown in Table-2.

As is clear from Table 2, the polymer of the present invention is superior in fluidity, appearance and impact strength to the polymer of PBT and a polymer of acrylates (Comparative Example 4). Compared with the one (comparative example 5)
It was excellent in appearance and impact strength.

Claims (1)

[Claims] 1. A thermoplastic resin composition comprising (A) a thermoplastic polyester, (B) a thermoplastic polyurethane, and (C) a polymer containing an alkyl acrylate or an alkyl methacrylate as a main component.