JP2600248B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermoplastic resin composition used as a material for molded articles for electric products and automobile parts, which is excellent in processability, impact resistance, and surface appearance of molded articles. It is about things.

[Prior art] Thermoplastic polyesters represented by polyethylene terephthalate and polybutylene terephthalate are used as molded articles in a wide variety of fields such as home electric appliances, electronic equipment parts, and automobile parts due to their excellent properties. And has a disadvantage of low impact resistance.

For the purpose of remedying this drawback, Japanese Patent Publication No. 58-47419 proposes a method of blending a copolymer comprising ethylene and glycidyl methacrylate. Is inferior.

[Problems to be Solved by the Invention] An object of the present invention is not only to improve the impact resistance of a thermoplastic polyester, but also to provide a resin molding material which is excellent in both moldability and appearance and has excellent overall properties. It is assumed that.

Means for Solving the Problems The present inventors have obtained a product having excellent appearance on the surface of a molded product by blending a copolymer of ethylene and glycidyl methacrylate with methyl methacrylate in a polyester resin. Although it could be obtained, it had the drawback that the impact resistance and workability were poor.

The present inventors add another polymer to the composition having good appearance in order to obtain a resin composition which is excellent in processability, impact resistance and surface appearance of a molded product and can be used for a wide range of applications. As a result of intensive studies, a graft copolymer and a rubbery copolymer obtained by grafting a (meth) acrylic acid alkyl ester to a copolymer mainly composed of an olefin unit and an epoxy group-containing unsaturated compound unit on a thermoplastic polyester were obtained. It has been found that by blending at a specific ratio, a thermoplastic resin composition having unprecedented overall excellent performance can be obtained, and the present invention has been completed based on such knowledge.

That is, the present invention relates to (a) thermoplastic polyester 9
To 99% by weight, (b) a graft copolymer obtained by grafting an alkyl (meth) acrylate to a copolymer mainly composed of an olefin unit and an epoxy group-containing unsaturated compound unit
A thermoplastic resin composition comprising 0.05 to 30% by weight and (c) 0.9 to 90% by weight of a rubbery polymer (excluding a graft copolymer).

The thermoplastic polyester (a) used in the present invention is a polyester compound composed of a dicarboxylic acid and a diol compound, and is a relatively high molecular weight, substantially linear thermoplastic polymer. Preferred are polymeric glycol esters of terephthalic acid and isophthalic acid.

Although these polymers are already commercially available, known production techniques (US Pat. No. 2,465,319,
U.S. Pat. No. 3,047,539).

That is, it can be produced by alcoholysis of phthalic acid ester with glycol and a subsequent polymerization reaction, and a production method by polymerization reaction of free phthalic acid or a halide derivative thereof with glycol by heating and a production method similar thereto. Can also be manufactured.

Preferred thermoplastic polyesters used in the present invention are those composed of a high molecular weight polymeric glycol terephthalate or glycol isophthalate having a repeating unit of the following formula and a mixture of these esters.

Here, n is preferably an integer of 2 to 10, and particularly preferably 2 to 4 in view of the physical properties of the composition. Further, a copolymer of terephthalic acid and isophthalic acid containing up to 30% of an isophthalic acid unit can also be suitably used.

Particularly preferred polyesters include poly-ethylene terephthalate and poly-1,4-butylene terephthalate.

Also, branched poly-ethylene terephthalate and branched poly-1,4-butylene terephthalate can be used. Such a branched polymer can contain a small amount of a branching component having at least three ester-forming groups, for example, up to 5 mol% based on terephthalic acid units.

The branching component may form a branch in the polyol unit other than the acid unit of the polyester, or may be a mixture of both. Examples of such branched components include:
Tri- or tetracarboxylic acids such as trimesic acid, trimellitic acid, pyromellitic acid and lower alkyl esters thereof, or polyols, preferably tetrols such as pentaerythritol and triols such as trimethylolpropane or dihydroxycarboxylic acid Acids and hydroxydicarboxylic acids and derivatives thereof include, for example, dimethyl hydroxyterephthalate.

These branched polyesters are described, for example, in U.S. Pat.
It can be produced by the same production method as the branched poly (1,4-butylene terephthalate) resin described in the specification of 3,404.

The high molecular weight polyesters useful in the practice of the present invention are at least 0.2 dl, for example, measured at a temperature of 25-30 ° C as a solution dissolved in o-chlorophenol or a mixture of phenol / tetrachloroethane = 60/40 by weight. / g
And an intrinsic viscosity of 0.4 to 2 dl / g.

As the polyester used in the present invention, copolyesters are also useful, for example, U.S. Patent No. 3,651,014,
Segment copolyesters having a large number of repeating ether esters and / or ester units as described in U.S. Pat. Nos. 3,763,109 and 3,766,146 can be suitably used.

The amount of the thermoplastic polyester used as the component (a) in the thermoplastic resin composition of the present invention was 9% of the total amount of the composition.
To 99% by weight, preferably 20 to 97% by weight, more preferably 30 to 95% by weight, particularly preferably 50 to 95% by weight.

If the amount is less than 9% by weight, the rigidity, workability and surface appearance of the molded product are inferior, and if it exceeds 99% by weight, the impact resistance is inferior.

The component (b) of the present invention comprises (meth) a copolymer mainly composed of an olefin unit and an epoxy group-containing unsaturated compound unit.
It is a graft copolymer obtained by grafting an alkyl acrylate.

In the present invention, the term "alkyl (meth) acrylate" is used as a general term for alkyl methacrylate and alkyl acrylate as conventionally used.

Examples of the olefin used in the production of the main chain copolymer of this component include ethylene, propylene, and butene-1. In particular, ethylene has good physical properties of the composition and ease of production of the component (b). From the viewpoint, it can be suitably used in the present invention.

As the epoxy group-containing unsaturated compound used for producing the main chain copolymer of this component, a compound having an unsaturated group capable of copolymerizing with an olefin and an epoxy group in one molecule is used.

For example, unsaturated epoxy compounds such as unsaturated glycidyl esters, unsaturated glycidyl ethers, epoxyalkenes and p-glycidylstyrenes represented by the following general formulas (I), (II) and (III) are used. Can be used.

In this formula, R is a C2-C18 hydrocarbon group having an ethylenically unsaturated bond.

In this formula, R is a hydrocarbon group having 2 to 18 carbon atoms which has an ethylenically unsaturated bond, X is -CH ₂ -O-, It is.

In this formula, R is a hydrocarbon group having 2 to 18 carbon atoms having an ethylenically unsaturated bond, and R 'is hydrogen or a methyl group.

Examples of the monomer used in the main chain copolymer of the component (b) of the present invention represented by such a formula include glycidyl acrylate, glycidyl methacrylate, glycidyl itaconate, butene carboxylate, allyl glycidyl ether, -Methylallyl glycidyl ether, styrene-p-glycidyl ether, 3,4-
Epoxybutene, 3,4-epoxy-3-methyl-1-butene-1-pentene, 3,4-epoxy-1-butene, 3,4-
Epoxy-3-methylpentene, 5,6-epoxy-1-
Hexene, vinylcyclohexene monoxide, p-glycidylstyrene and the like can be mentioned.

In the present invention, one or more of these can be used.

(B) The weight ratio of the olefin and the epoxy group-containing unsaturated compound in the main chain copolymer in the component, that is, the weight ratio of the olefin component to the epoxy group-containing unsaturated compound component is 99: 1 to 60:40. Yes, preferably from 97: 3 to 70:30.

In addition, the main chain copolymer of the component (b) may optionally have
By other vinyl monomers copolymerizable with the above monomers,
What substituted the olefin component of the said main-chain copolymer to 50 weight%, preferably 20 weight%, more preferably 10 weight% can be used.

Other copolymerizable vinyl monomers that can be used herein include styrene, α-methylstyrene, methylstyrene, aromatic vinyl compounds such as vinyl xylene, acrylic acid, unsaturated acids such as methacrylic acid, and anhydrides. Maleic acid, unsaturated acid anhydrides such as itaconic anhydride, propylene,
Α-olefins such as butene-1, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, methyl acrylate, ethyl acrylate propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate Alkyl acrylates such as octadecyl acrylate, phenyl acrylate and benzyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate Methacrylic acid alkyl esters such as phenyl methacrylate and benzyl methacrylate, maleimide, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-laurylmaleimide, N-phenylmaleimide, N- (p-bromophenyl) There are maleimide compounds such as maleimide and cyclohexylmaleimide, and vinyl acetate. One or more of these copolymerizable other vinyl monomers can be used.

The component (b) of the present invention can be produced by grafting an alkyl (meth) acrylate to a main chain copolymer.

The (meth) acrylic ester component used as the graft component may be composed of (meth) acrylic acid alkyl ester monomers alone or in the form of a mixed monomer, their (co) polymers, and other copolymerizable with them. Those produced by copolymerizing a vinyl monomer can be used.

As the alkyl (meth) acrylate and the other copolymerizable vinyl monomer used herein, any vinyl monomer that can be used as desired in the main chain copolymer can be used. In the invention, in particular,
A graft component consisting of a single monomer of methyl methacrylate is preferred.

The weight ratio of the main chain copolymer component to the graft component used in the production of the component (b) of the present invention is preferably 95: 5 to 30:70, and the raw materials are preferably used.

The component (b) of the present invention can be usually produced by a method of causing a polymer addition reaction of a graft component to a main chain copolymer component or a method of causing a graft polymerization reaction of a graft monomer unit to a main chain polymer. However, in the actual addition reaction or polymerization reaction, a part of the raw materials blended for grafting is introduced as a graft side chain, and the other raw materials are converted into a main chain copolymer and a free polymer in the product. May be present as a mixture.

As the component (b) of the present invention, one in which at least 1% by weight or more of the raw material of the used graft component is introduced into the graft side chain can be used.

Regarding the graft copolymer of the component (b) in the present invention, the entire mixture containing components other than the graft copolymer produced by the above-described production method is regarded as the graft copolymer, and the amount of the composition Has been stipulated.

Examples of the method for producing the component (b) of the present invention include the following methods.

i) A method of adding a polymer composed of an alkyl (meth) acrylate unit having a —O—O— bond in a molecule by a polymer reaction, for example, adding a copolymer of polyperoxide and methyl methacrylate to ethylene -A method of grafting to an epoxy group-containing unsaturated compound copolymer by a radical addition reaction in an extruder or a solution.

ii) A method of polymerizing an alkyl (meth) acrylate, for example, methyl methacrylate in the presence of an ethylene-epoxy group-containing unsaturated compound copolymer to carry out a graft reaction.

iii) It can be produced by melt-mixing an alkyl (meth) acrylate polymer, for example, a methyl methacrylate polymer and an ethylene-epoxy group-containing unsaturated compound copolymer in the presence of a peroxide.

In the graft polymers produced by the above methods i) and iii), the distinction between the main chain and the graft side chain is not clear, but in the present invention, the chain of the epoxy-containing copolymer is changed regardless of the polymer mechanism. Defined as the main chain.

A preferred method for producing the component (b) used in the present invention is i)
This is a method known in the art, for example, methyl methacrylate and polyperoxide are heated under an inert gas atmosphere at a temperature.
It can be produced by polymerizing at 65 ° C. and grafting this to the main chain polymer by the method of i) (Polymer Transactions, Vol. 44, No. 2, pp. 81-95, 1987).
Year).

As the component (b) of the present invention, commercially available MODIPER (trade name, manufactured by NOF Corporation) can be suitably used.

The molecular weight of the polymer to be grafted to the component (b) of the present invention is preferably 50,000 to 300,000 (weight average molecular weight in terms of polystyrene), and the component (b) itself has a multiphase mechanism by these grafts. Are preferred to achieve the object of the present invention.

The amount of the component (b) used in the thermoplastic resin composition of the present invention is 0.05 to 30% by weight based on the total amount of the composition, and is preferably
0.2 to 20% by weight, more preferably 0.3 to 10% by weight, particularly preferably 0.5 to 10% by weight can be added.

If the amount is less than 0.05% by weight, the impact resistance and the surface appearance of the molded product are inferior, and when a pellet composition is obtained by using an extruder, the strand is disturbed and industrial production becomes difficult,
If it exceeds 30% by weight, processability is poor.

Examples of the rubbery polymer as the component (c) of the present invention include diene rubbers such as polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, and polyisoprene; ethylene-α-olefin copolymer; Non-diene rubber such as α-olefin-polyene copolymer, polyacrylate, styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, ethylene-propylene elastomer, styrene-grafted ethylene-propylene elastomer , An ethylene-based ionomer resin, a hydrogenated styrene-isoprene block copolymer, and the like.

Such styrene-butadiene block copolymers include AB type, ABA type, ABA taper type, radial teleblock type and the like.

One or more of these rubbery polymers can be used.

Among these rubbery polymers, ethylene-α-olefin copolymers, ethylene-α-olefin-polyene copolymers, and styrene-butadiene block copolymers are preferred in terms of impact resistance, processability, and surface appearance of molded articles. A copolymer, a hydrogenated styrene-butadiene block copolymer, and a hydrogenated styrene-isoprene block copolymer are preferred, and an ethylene-α-olefin copolymer is particularly preferred.

The weight ratio of ethylene to α-olefin of the ethylene-α-olefin copolymer used here is 95: 5 to 5:95, preferably 95: 5 to 20:80, and more preferably 92: 8 to 60. :Four
0, particularly preferably 85:15 to 70:30.

When the weight ratio of ethylene to α-olefin used in the component (c) of the present invention is in the range of 20:80 to 30:70, the moldability of the composition of the present invention is particularly improved.

Also, from the viewpoint of improving the impact resistance, ethylene and α
-It is desirable to have the olefin weight ratio in the range of 80:20 to 70:25.

The Mooney viscosity (ML _{1 + 4,100} ° C.) of the ethylene-α-olefin copolymer used in the component (c) of the present invention is 5 to 200, preferably 5 to 100, more preferably 5 to ₁₀₀ from the viewpoint of impact resistance. ~ 50 are desirable. Mooney viscosity is 10 ~
In the range of 30, the impact resistance of the composition is particularly improved.

The cyclohexane insoluble content of the ethylene-α-olefin copolymer affects the processability and impact resistance of the thermoplastic resin composition of the present invention, and is 50% by weight or less, preferably 5% by weight or less.

The α-olefin used herein is an unsaturated hydrocarbon compound having 3 to 20 carbon atoms, for example, propylene, butene-1, pentene-1, hexene-1, heptene-1, 4-methylbutene- 1,4-methylpentene-1 and the like. Particularly preferred is propylene.

The amount of the component (c) used in the thermoplastic resin composition of the present invention is 0.9 to 90% by weight, preferably 2 to 75% by weight, more preferably 3 to 70% by weight, and particularly preferably 5 to 60% by weight. %. If it is less than 0.9% by weight, the impact resistance is poor, and if it exceeds 90% by weight, the processability and the surface appearance of the molded product are poor.

In the present invention, by using the component (b) and the component (c) together, it is possible to obtain a composition having high impact resistance, which cannot be obtained by the component (b) alone or the component (c) alone.

In this case, the weight ratio of the component (b) to the component (c) is 1:
It is preferable to select an appropriate value in the range of 99 to 50:50.

The thermoplastic resin composition of the present invention, various extruders, Banbury mixer, kneader, roll, etc. 200 ° C. ~ 350 ° C.
By kneading the components at a temperature of

A preferred kneading method is a method using a kneading extruder, and a particularly preferred extruder is a twin-screw co-rotating extruder.

When using the thermoplastic resin composition of the present invention, various fillers can be added.

For example, glass fiber, carbon fiber, metal fiber, glass beads, asbestos, wollastonite, calcium carbonate,
Fillers such as talc, barium sulfate, mica, potassium titanate, fluororesin, and molybdenum disulfide can be used alone or in combination.

Among these fillers, those having a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more are preferable as a fiber shape such as glass fiber and carbon fiber.

These fillers can be used in an amount of 5 to 150 parts by weight based on 100 parts by weight of the thermoplastic resin composition.

In addition, known additives such as a flame retardant, an antioxidant, and a plasticizer can be used. Preferred flame retardants are of the halogen type, for example, brominated polystyrene, brominated polyphenylene ether, brominated epoxy oligomer and the like.

Further polymers depending on the required performance, such as AB
S resin, AS resin, HIPS, polystyrene, polyamide, polyethylene, polypropylene, polycarbonate, polysulfone, polyethersulfone, polyimide, PPS,
Polyetheretherketone, vinylidene fluoride polymer polyphenylether and the like can be appropriately blended.

The thermoplastic resin composition of the present invention can be used as various products by injection molding, sheet extrusion, vacuum molding, heterogeneous molding, foam molding and the like.

Various molded products obtained by the above molding method, utilizing its excellent performance, automobile exterior, interior members and electricity,
It can be used for various electronic parts, housings, etc.

[Examples] The present invention will be described in more detail by way of examples, but these are all illustrative and do not limit the content of the present invention.

In the following examples, parts and% indicate parts by weight and% by weight, respectively.

(A) of the present invention used in Examples and Comparative Examples of the present invention,
The components (b) and (c) are shown below.

1 (a) Component A-1: Polybutylene terephthalate, Polyplastics Co., Ltd., trade name Duranex XD477 A-2; Polyethylene terephthalate, Nippon Unipet Co., Ltd., product name Unipet RT543 2 (b) Component B -1; ethylene-glycidyl methacrylate (GMA)
Polymer (ethylene / GMA = 85/15) grafted with methyl methacrylate polymer (ethylene +
GMA / methyl methacrylate polymer = 70/30), manufactured by NOF CORPORATION, trade name Modiper A4200 B-2; a polymer of ethylene / GMA = 92/8 in B-1 B-3; Polymer having GMA = 95/5 B-4; a polymer in which the graft component in B-1 is polystyrene, trade name MODIPER A4100 B-5, manufactured by NOF Corporation; ethylene-glycidyl methacrylate, manufactured by Sumitomo Chemical Co., Ltd. Trade name Bond Fast E3 (c) component C-1; ethylene-propylene copolymer, trade name EP-02P (Mooney viscosity ML _{1 +} 424) manufactured by Nippon Synthetic Rubber Co., Ltd. C-2; ethylene-propylene copolymer Polymer, trade name EP-941P (Mooney viscosity ML _{1 +} 442) manufactured by Japan Synthetic Rubber Co., Ltd. C-3; styrene-butadiene-styrene block copolymer, trade name TR-2000 manufactured by Japan Synthetic Rubber Co., Ltd. C-4; hydrogenated styrene-butadiene-styrene block copolymer Body, Shell Corporation, trade name Kraton G1650 embodiment, according to the formulation ratio of Table 1 Comparative Example (a), (b), a mixture of component (c), a barrel set temperature by using a twin-screw extruder 240
The mixture was kneaded and extruded at a temperature of 280 ° C. (280 ° C. when A-2 was used as the component (a)) and pelletized. The obtained pellets were sufficiently dried, and a test piece for impact resistance and molded article surface appearance evaluation was prepared using an injection molding machine and evaluated according to the following evaluation criteria.

 Table 1 shows the evaluation results.

Evaluation Test Method Impact Resistance: Izod impact strength was measured at 23 ° C. with a notch at 1/4 ″ according to ASTM D256.

Surface appearance of molded article: A plate-like molded article was obtained, and the smoothness of the appearance was visually evaluated according to the following evaluation criteria.

◎; very good ○; excellent △; slightly poor ×; poor workability; using dried pellets, 240 ° C according to JISK7210
(280 ° C. when A-2 was used as the component (a)), and measured under a load of 10 kg. The following can be seen from the results of the comparative examples in Table 1.

Comparative Example 1 is an example of polybutylene terephthalate alone, and has poor impact resistance.

In Comparative Example 2, the graft component of the component (b) is outside the scope of the present invention, and the impact resistance and the appearance of the molded product are poor.

Comparative Example 3 had no graft component (b), and was inferior in molded product appearance and workability.

Comparative Example 4 is an example in which the component (B) of the present invention was not used, and was inferior in impact resistance and appearance of a molded product.

Comparative Example 5 is an example in which the component (c) of the present invention was not used, and was inferior in impact resistance and workability.

In Comparative Example 6, the amount of the component (b) used in the present invention was outside the range of the present invention, and the impact resistance and the appearance of the molded product were poor.

[Effects of the Invention] The composition of the present invention is an excellent resin in which impact resistance, appearance of a molded article and moldability are highly balanced.

Accordingly, the composition of the present invention provides molded articles such as exterior and interior parts of automobiles and various electric and electronic parts and housings, which require such highly balanced physical properties. The utility value of is extremely large.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shinichi Kimura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-1-138261 (JP, A) JP-A Sho 63-312313 (JP, A) JP-A-60-63250 (JP, A)

Claims (1)

(57) [Claims] 1. A graft copolymer obtained by grafting (a) 9 to 99% by weight of a thermoplastic polyester and (b) a copolymer mainly composed of an olefin unit and an epoxy group-containing unsaturated compound unit with an alkyl (meth) acrylate ester. Polymer 0.05-30
(C) a thermoplastic resin composition comprising 0.9 to 90% by weight of a rubbery polymer (excluding a graft copolymer);