JP2021031567A - Thermoplastic resin composition and molded article thereof - Google Patents

Abstract

To provide a thermoplastic resin composition that has good mechanical properties, particularly a weld strength, and has a small amount of warpage in the molded article, and to provide a molded article thereof.SOLUTION: Provided are: a thermoplastic resin composition containing (A) a thermoplastic polyester resin by 70 to 95 pts.mass, (B) a vinyl-based copolymer containing an aromatic vinyl monomer unit and a vinyl cyanide monomer unit as constituent elements (excluding epoxy-modified vinyl-based copolymer (C)) by 1 to 30 pts.mass, and (C) an epoxy-modified vinyl-based copolymer by 0.1 to 15 pts.mass so that the total is 100 pts.mass, and containing, for 100 pts.mass of the total of the (A) thermoplastic polyester resin, (B) vinyl-based copolymer and (C) epoxy-modified vinyl-based copolymer, (D) a fiber reinforcement material by 1 to 50 pts.mass; and a molded article comprising said thermoplastic resin composition.SELECTED DRAWING: Figure 1

Description

The present invention is a thermoplastic obtained by blending a fiber reinforcing material with a resin component containing a thermoplastic polyester resin, an epoxy-modified vinyl-based copolymer, and a vinyl-based copolymer different from the epoxy-modified vinyl-based copolymer. The present invention relates to a thermoplastic resin composition which is a resin composition and has a good warp suppressing effect, mechanical strength, particularly weld strength of the obtained molded product, and a molded product obtained by molding the thermoplastic resin composition.

Thermoplastic polyesters such as polybutylene terephthalate and polyethylene terephthalate are excellent in workability, mechanical properties, and other physical and chemical properties, so they are used for automobile parts, electrical and electronic equipment parts, and other precision equipment. Widely used in the field of parts and the like.

However, thermoplastic polyesters, especially crystalline resins such as polybutylene terephthalate (hereinafter, also referred to as "PBT"), are used during molding, for example, during the process of cooling and solidifying in a mold during injection molding. It is known that molding shrinkage occurs due to molecular orientation that accompanies the crystallization of. Since the degree of shrinkage varies depending on the part of the molded product, as a result, the molded product is warped or twisted. In particular, PBT containing a fiber reinforcing material such as glass fiber tends to have a larger warp and twist due to the influence of the orientation of the glass fiber.

As a method for suppressing warpage and twisting of this molded product, alloying with an amorphous resin such as an acrylonitrile / styrene copolymer or ABS resin is common.
However, while alloying with an amorphous resin such as an acrylonitrile / styrene copolymer or ABS resin can suppress warpage and twisting of the molded product, there is a concern that the mechanical strength may decrease from the viewpoint of compatibility. In particular, in a molded product having a weld portion, the strength of the weld portion may decrease, which may limit the members and applications that can be used.

Conventionally, the following proposals have been made for the purpose of improving the weld strength of a material in which a glass fiber reinforced PBT and an amorphous resin are alloyed.

Patent Document 1 proposes to blend a copolymer obtained by polymerizing a vinyl cyanide monomer, an aromatic vinyl monomer, and an epoxy group-containing vinyl monomer. However, in this technique, although the weld strength is improved, the amount of the copolymer obtained by polymerizing the vinyl cyanide monomer, the aromatic vinyl monomer and the epoxy group-containing vinyl monomer is large, and the heat is high. It may also impair the properties of the plastic polyester resin. Moreover, there is no description about the warp suppressing effect, and it is unclear.

Patent Document 2 proposes to blend an epoxy group-containing styrene block copolymer for the purpose of improving the weld characteristics of an alloy material of a thermoplastic polyester resin and a rubber-reinforced styrene resin. Although it can be confirmed that the weld strength is improved by this technique, the effect is not sufficient. Further, as in Patent Document 1, there is no description about the warp suppressing effect of the molded product, and it is unlikely that the method can satisfy both the warp suppressing effect and the weld strength.

Patent Document 3 proposes to blend an acrylonitrile-styrene copolymer for the purpose of suppressing warpage of a polybutylene terephthalate resin reinforced with glass fibers. Although the warp suppressing effect of the molded product can be confirmed by this technique, there is no description about the weld strength, and it is unlikely that the method can satisfy both the warp suppressing and the weld strength.

Japanese Unexamined Patent Publication No. 5-202252 Japanese Unexamined Patent Publication No. 9-176435 JP-A-2018-70722

The present invention provides a thermoplastic resin composition and a molded product thereof, which can obtain a molded product having excellent mechanical properties, particularly weld strength and a small amount of warpage, in a fiber-reinforced thermoplastic polyester-based resin composition. With the goal.

As a result of repeated studies to solve the above problems, the present inventor has specified a thermoplastic polyester resin (A), a vinyl-based copolymer (B), and an epoxy-modified vinyl-based copolymer (C) as resin components. It has been found that the effect of suppressing warpage of the molded product and the effect of improving the mechanical strength, particularly the weld strength, can be achieved at the same time by blending in the ratio of.
That is, the gist of the present invention is as follows.

[1] A vinyl-based copolymer (B) containing 70 to 95 parts by mass of a thermoplastic polyester resin (A), an aromatic vinyl monomer unit and a vinyl cyanide monomer unit as constituent elements (however, an epoxy-modified vinyl-based resin). The thermoplastic polyester resin contains 1 to 30 parts by mass of the copolymer (C) and 0.1 to 15 parts by mass of the epoxy-modified vinyl-based copolymer (C) so as to have a total of 100 parts by mass. A thermoplastic resin composition containing 1 to 50 parts by mass of the fiber reinforcing material (D) with respect to a total of 100 parts by mass of (A), the vinyl-based copolymer (B) and the epoxy-modified vinyl-based copolymer (C). ..

[2] The epoxy-modified vinyl-based copolymer (C) contains 0.1 to 95 parts by mass of an epoxy group-containing vinyl monomer unit, an aromatic vinyl monomer unit, a vinyl cyanide monomer unit, and these. Containing 5 to 99.9 parts by mass of one or more vinyl monomer units selected from other vinyl monomer units copolymerizable with (however, epoxy group-containing vinyl monomer units and aromatic vinyl singles). 100 parts by mass in total with a weight unit, a vinyl cyanide monomer unit, and one or more vinyl monomer units selected from other vinyl monomers copolymerizable therewith), [1]. Thermoplastic resin composition.

[3] The epoxy-modified vinyl-based copolymer (C) contains 4.1 to 99 parts by mass of an aromatic vinyl monomer unit and 0.9 to 95.8 parts by mass of a vinyl cyanide monomer unit. , [2].

[4] The thermoplastic resin composition according to any one of [1] to [3], wherein the epoxy-modified vinyl copolymer (C) has a weight average molecular weight Mw of 50,000 to 300,000.

[5] The epoxy equivalent of the epoxy-modified vinyl copolymer (C) is 150 to 143,000 g / eq. The thermoplastic resin composition according to any one of [1] to [4].

[6] The epoxy-modified vinyl-based copolymer (C) is measured at a temperature of 10 ° C./min and Air of 50 ml / min as measurement conditions using differential scanning calorimetry (DSC). The thermoplastic resin composition according to any one of [1] to [5], which can be observed to exhibit heat absorption behavior between 90 ° C. and 120 ° C. and heat generation behavior between measurement temperatures of 260 ° C. and 300 ° C. Stuff.

[7] A molded product comprising the thermoplastic resin composition according to any one of [1] to [6].

According to the present invention, there is provided a fiber-reinforced thermoplastic polyester resin composition having good mechanical properties, particularly weld strength, and a small amount of warpage of the molded product, and the molded product thereof.

It is a DSC chart of the epoxy-modified vinyl-based copolymers (C-1) and (C-2) produced in Production Example 1.

Embodiments of the present invention will be described in detail below.

In the specification of the present application, the "unit" means a structural portion derived from a compound (monomer, that is, a monomer) before polymerization contained in a polymer or a copolymer, and for example, "aromatic vinyl". The "monomer unit" means "a structural portion derived from an aromatic vinyl monomer and contained in the copolymer". The content ratio of the monomer unit of each copolymer corresponds to the content ratio of the monomer in the vinyl monomer mixture used for producing the copolymer.
The "molded product" is a product obtained by molding a thermoplastic resin composition.
Further, "~" indicating a numerical range means that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention is a vinyl-based copolymer (B) containing 70 to 95 parts by mass of the thermoplastic polyester resin (A), an aromatic vinyl monomer unit and a vinyl cyanide monomer unit as constituent elements. ) (However, excluding the epoxy-modified vinyl-based copolymer (C)) 1 to 30 parts by mass and 5 to 15 parts by mass of the epoxy-modified vinyl-based copolymer (C) are included so as to make a total of 100 parts by mass. The fiber reinforcing material (D) is contained in an amount of 1 to 50 parts by mass based on 100 parts by mass of the total of the thermoplastic polyester resin (A), the vinyl-based copolymer (B) and the epoxy-modified vinyl-based copolymer (C). It is characterized by that.

[Thermoplastic polyester resin (A)]
Examples of the thermoplastic polyester resin (A) include a polymer or a copolymer obtained by a polycondensation reaction containing a dicarboxylic acid (or an ester-forming derivative thereof) and a diol (or an ester-forming derivative thereof) as main components. Can be used.

Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 3,3'. -Biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylsulphondicarboxylic acid, 4,4'-diphenylisopropyridene Dicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, 2,5-anthracendicarboxylic acid, 2,6-anthracendicarboxylic acid, 4,4'-p-terphenylenedicarboxylic acid, 2 , 5-Aromatic dicarboxylic acids such as pyridinedicarboxylic acids. Of these, terephthalic acid is preferable.

Two or more of these dicarboxylic acid components may be mixed and used. If the amount is small, one or more of the aliphatic dicarboxylic acid components such as adipic acid, azelaic acid, dodecandioic acid, and sebacic acid, and the alicyclic dicarboxylic acid component such as cyclohexanedicarboxylic acid are mixed and used together with these dicarboxylic acid components. can do.

Examples of the diol component include aliphatic diols such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, diethylene glycol and triethylene glycol, and 1,4-cyclohexanedi. Examples thereof include alicyclic diols such as methanol and mixtures thereof. Of these, ethylene glycol, propylene glycol, and butylene glycol are preferable. If the amount is small, a long chain diol having a molecular weight of 400 to 6,000, that is, one or more of polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol, and the like may be mixed and used.

Preferred examples of these polymers or copolymers are polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene terephthalate (PBN), and polyethylene-. Examples include aromatic polyester resins such as 1,2-bis (phenoxy) ethane-4,4'-dicarboxylate and copolymerized aromatic polyester resins such as polybutylene terephthalate / isophthalate and polybutylene terephthalate / decandicarboxylate. .. Of these, PET and PBT are preferable from the viewpoint of ease of workability and mechanical properties.

These thermoplastic polyester resins (A) can be used by mixing two or more kinds of thermoplastic polyester resins, and may be, for example, a mixture of PET and PBT.

[Vinyl copolymer (B)]
The vinyl-based copolymer (B) contains at least an aromatic vinyl monomer unit and a vinyl cyanide monomer unit as constituent elements.

Examples of the aromatic vinyl monomer constituting the vinyl copolymer (B) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, ethylstyrene, vinyltoluene, vinylxylene, and methyl-. α-Methylstyrene, t-butylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl-p-aminomethylstyrene, N, N-diethyl-p-aminoethylstyrene, vinylnaphthalene, vinylpyridine, Chlorinated styrene such as monochlorostyrene and dichlorostyrene; brominated styrene such as monobromostyrene and dibromostyrene; monofluorostyrene and the like can be mentioned. Of these, styrene and α-methylstyrene are preferable. These aromatic vinyl monomers may be used alone or in admixture of two or more.

Examples of the vinyl cyanide monomer constituting the vinyl-based copolymer (B) include acrylonitrile, methacrylonitrile, etacrylonitrile, and fumaronitrile. Of these, acrylonitrile is preferable. These vinyl cyanide monomers may be used alone or in admixture of two or more.

The vinyl-based copolymer (B) may contain other vinyl monomer units copolymerizable with these in addition to the aromatic vinyl monomer unit and the vinyl cyanide monomer unit, and other vinyl monopolymers may be contained. Specifically, the quantities include acrylates (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, etc.) and methacrylates (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl acrylate, etc.). Etc.), maleimide compounds (N-cyclohexyl maleimide, N-phenylmaleimide, etc.) and the like. Other vinyl monomers may be used alone or in admixture of two or more.
The vinyl-based copolymer (B) according to the present invention is different from the epoxy-modified vinyl-based copolymer (C) described later, and therefore, the epoxy-modified vinyl polymer is different from other vinyl monomers. Vinyl monomers that can be (C) are excluded.

The content of the aromatic vinyl monomer unit in 100 parts by mass of the vinyl-based copolymer (B) is preferably 50 to 90 parts by mass, more preferably 55 to 80 parts by mass, and even more preferably 40 to 70 parts by mass. When the content of the aromatic vinyl monomer is within the above range, the warpage property of the obtained molded product is good.
The content of the vinyl cyanide monomer unit in 100 parts by mass of the vinyl copolymer (B) is preferably 10 to 50 parts by mass, more preferably 20 to 45 parts by mass, and further 30 to 60 parts by mass. preferable. When the content of the vinyl cyanide monomer unit is within the above range, the warpage property of the obtained molded product is good.
The content in 100 parts by mass of the vinyl-based copolymer (B) of other vinyl monomer units copolymerizable with these is preferably 0 to 30 parts by mass.

The weight average molecular weight Mw of the vinyl-based copolymer (B) is preferably 50,000 to 300,000, particularly preferably 60,000 to 250,000. When the weight average molecular weight Mw of the vinyl-based copolymer (B) is within the above range, the fluidity and impact resistance of the obtained thermoplastic resin composition tend to be good.
The weight average molecular weight Mw of the vinyl-based copolymer (B) is measured by the method described in the section of Examples below.

In the thermoplastic resin composition of the present invention, only one type of vinyl-based copolymer (B) may be contained, and two or more types having different types, compositions, physical properties, etc. of vinyl monomer units may be contained. It may be included.

[Epoxy-modified vinyl copolymer (C)]
The epoxy-modified vinyl-based copolymer (C) according to the present invention can be copolymerized with an epoxy group-containing vinyl monomer, an aromatic vinyl monomer, a vinyl cyanide monomer, and those used as necessary. It is obtained by copolymerizing with one or more kinds of vinyl monomers selected from other vinyl monomers (hereinafter, may be referred to as "other vinyl monomers").
The epoxy-modified vinyl-based copolymer (C) is preferably obtained by copolymerizing at least a monomer mixture containing an epoxy group-containing vinyl monomer, an aromatic vinyl monomer and a vinyl cyanide monomer. .. When a vinyl monomer such as an aromatic vinyl monomer or a vinyl cyanide monomer has an epoxy group, these are included in the epoxy group-containing vinyl monomer.

The thermoplastic resin composition of the present invention may contain only one type of epoxy-modified vinyl-based copolymer (C), and the type and composition of the vinyl monomer unit contained, physical properties described later, and the like may be used. It may contain two or more different types.

<Vinyl monomer>
Examples of the epoxy group-containing vinyl monomer constituting the epoxy-modified vinyl copolymer (C) include glycidyl acrylate, glycidyl methacrylate, glycidyl ester of itaconic acid, allyl glycidyl ether, styrene-p-glycidyl ether, 3,4. -Epoxide butene, 3,4-epoxide-3-methyl-1-butene, 3,4-epoxide-1-pentene, 3,4-epoxide-3-methylpentene, 5,6-epoxy-1-hexene, vinyl Cyclohexene monooxide, p-glycidyl styrene, 2-methylallyl glycidyl ether, epoxystearyl acrylate, epoxystearyl metacrate, 3,4-epoxycyclohexylmethylmethacrylate, 3,4-epoxycyclohexylmethylacrylate, 2,6-xylenol- Examples thereof include glycidyl ether of N-methylol acrylamide. Of these, glycidyl methacrylate is preferable. These epoxy group-containing vinyl monomers may be used alone or in admixture of two or more.

Examples of the aromatic vinyl monomer, vinyl cyanide monomer and other vinyl monomer include those exemplified in the description of the vinyl-based copolymer (B), and preferred aromatic vinyl monomer and cyanide. The same applies to the vinyl chloride monomer.

<Contents of each vinyl monomer>
The content of the epoxy group-containing vinyl monomer unit in the epoxy-modified vinyl copolymer (C) is preferably 0.1 to 95 parts by mass, more preferably 1 to 30 parts by mass, and particularly preferably 2 to 2 parts by mass. It is 15 parts by mass. When the content of the epoxy group-containing vinyl monomer unit in the epoxy-modified vinyl copolymer (C) is 0.1 parts by mass or more, the mechanical strength, particularly the weld strength, of the obtained thermoplastic resin composition is good. It becomes. If the content of the epoxy group-containing vinyl monomer unit exceeds 95 parts by mass, the fluidity of the thermoplastic resin composition obtained by gelation may be impaired.

The vinyl monomer units excluding the epoxy group-containing vinyl monomer unit in the epoxy-modified vinyl copolymer (C) are aromatic vinyl monomer, vinyl cyanide monomer and other vinyl monomer. One or more vinyl monomer units selected from. The total content of the vinyl monomer unit excluding the epoxy group-containing vinyl monomer unit in the epoxy-modified vinyl copolymer (C) is preferably 5 to 99.9 parts by mass, and further 70 to 99 parts by mass. By mass is preferable, and 85 to 98 parts by mass is particularly preferable. When the content of these vinyl monomer units exceeds 99.9 parts by mass, the mechanical strength, particularly the weld strength, of the obtained thermoplastic resin composition tends to decrease. If the content of these vinyl monomer units is less than 5 parts by mass, the fluidity of the obtained thermoplastic resin composition may be impaired.

In the present invention, the content of each vinyl monomer unit in the epoxy-modified vinyl-based copolymer (C) is the content in 100 parts by mass of the epoxy-modified vinyl-based copolymer (C), that is, an epoxy group. 100 parts by mass of the total of the contained vinyl monomer unit and one or more vinyl monomer units selected from the aromatic vinyl monomer unit, the vinyl cyanide monomer unit and the other vinyl monomer unit. It is the content when. The content of the vinyl monomer unit in the epoxy-modified vinyl-based copolymer (C) is usually a single amount of epoxy group-containing vinyl which is a copolymerization raw material in producing the epoxy-modified vinyl-based copolymer (C). Content of each vinyl monomer in 100 parts by mass of a mixture of the body and one or more vinyl monomers selected from aromatic vinyl monomer, vinyl cyanide monomer and other vinyl monomer. Corresponds to.

The epoxy-modified vinyl copolymer (C) of the present invention is one or more vinyl monomer units selected from aromatic vinyl monomer units, vinyl cyanide monomer units and other vinyl monomer units. It is preferable to contain at least an aromatic vinyl monomer unit and a vinyl cyanide monomer unit.

The content of the aromatic vinyl monomer unit in the epoxy-modified vinyl copolymer (C) is 4.1 to 99 parts by mass, more preferably 30 to 95 parts by mass, and particularly preferably 60 to 80 parts by mass. If the content of the aromatic vinyl monomer unit is less than 4.1 parts by mass, the rigidity and moldability of the obtained molded product may be inferior. If the content of the aromatic vinyl monomer unit exceeds 99 parts by mass, the impact resistance of the obtained molded product may decrease.

The content of the vinyl cyanide monomer unit in the epoxy-modified vinyl copolymer (C) is 0.9 to 95.8 parts by mass, more preferably 4.9 to 40 parts by mass, and particularly preferably 5 to 38 parts by mass. .. If the content of the vinyl cyanide monomer unit is less than 0.9 parts by mass, the toughness and chemical resistance of the obtained molded product may be inferior. If the content of the vinyl cyanide monomer unit exceeds 95.8 parts by mass, coloring of the obtained molded product may become a problem.

Other vinyl monomers can be blended according to the purpose of improving color development and heat resistance. The content of the other vinyl monomer unit in the epoxy-modified vinyl copolymer (C) is preferably 0 to 30 parts by mass, and more preferably 0 to 20 parts by mass.

<Weight average molecular weight Mw / molecular weight distribution Mw / Mn>
The weight average molecular weight Mw of the epoxy-modified vinyl copolymer (C) is preferably 50,000 to 300,000, more preferably 70,000 to 280,000. When the weight average molecular weight Mw is in this range, the effect of improving the warp property and the mechanical strength of the thermoplastic resin composition containing the epoxy-modified vinyl copolymer (C) can be more effectively exhibited. it can.

The molecular weight distribution Mw / Mn of the epoxy-modified vinyl copolymer (C) is preferably 1.8 to 2.5, and more preferably 1.9 to 2.3. When the molecular weight distribution Mw / Mn is in this range, the fluidity and heat resistance of the thermoplastic resin composition containing the epoxy-modified vinyl copolymer (C) tend to be good.

The weight average molecular weight Mw and the molecular weight distribution Mw / Mn of the thermoplastic polyester resin (A) are measured by the methods described in the section of Examples below.

<Epoxy equivalent>
The epoxy equivalent of the epoxy-modified vinyl copolymer (C) is 150 to 143,000 g / eq. Is preferable, and more preferably 500 to 10,000 g / eq. Particularly preferably, 1,000 to 5,000 g / eq. Is. When the epoxy equivalent is in this range, the warp property and the effect of improving the mechanical strength of the thermoplastic resin composition containing the epoxy-modified vinyl copolymer (C) can be more effectively exhibited.

The epoxy equivalent of the epoxy-modified vinyl copolymer (C) is measured by the method described in the section of Examples below.

<Reduced viscosity>
In order to secure a balance between impact resistance and moldability of the obtained thermoplastic resin composition, the reducing viscosity of the epoxy-modified vinyl copolymer (C) is preferably 0.2 to 1.2 dL / g. , 0.3 to 1.1 dL / g, more preferably. When the reducing viscosity of the epoxy-modified vinyl copolymer (C) is at least the above lower limit, the mechanical strength becomes higher. When the reducing viscosity of the epoxy-modified vinyl copolymer (C) is not more than the above upper limit, good appearance and moldability of the molded product can be maintained.

The reduced viscosity of the epoxy-modified vinyl copolymer (C) is measured by the method described in the section of Examples below.

<Endothermic and heat generation behavior>
The epoxy-modified vinyl copolymer (C) uses differential scanning calorimetry (DSC) and has a measurement temperature of 90 ° C. to 120 ° C. under an atmosphere of a heating rate of 10 ° C./min and Air of 50 ml / min as measurement conditions. It is preferable that it can be observed that the heat absorption behavior is exhibited during the ° C. and the heat generation behavior is exhibited between the measurement temperature of 260 ° C. and 300 ° C. Further, those exhibiting a rapid endothermic behavior between the measurement temperature of 100 ° C. and 120 ° C. and a rapid heat generation behavior between the measurement temperature of 280 ° C. and 300 ° C. are more preferable.
A thermoplastic resin composition containing an epoxy-modified vinyl-based copolymer (C) that exhibits endothermic and heat-generating behavior in these temperature ranges has good mechanical strength, and the amount of warpage of the obtained molded product is higher. It will be small.

The endothermic and exothermic behavior of the epoxy-modified vinyl copolymer (C) is observed by the measuring method described in the section of Examples described later.

<Manufacturing method of epoxy-modified vinyl copolymer (C)>
Examples of the polymerization method for producing the epoxy-modified vinyl copolymer (C) include suspension polymerization, bulk polymerization, emulsion polymerization and solution polymerization. Of these, the suspension polymerization method is preferable.

[Fiber Reinforcement Material (D)]
Examples of the fiber reinforcing material (D) include talc, aluminum hydroxide, glass flakes, glass beads, glass fibers, wallastenite, potassium titanate whisker, zinc oxide whisker, carbon fiber, alumina fiber, silicon carbide fiber, and ceramic fiber. , Asbestos fiber, stone fiber, metal fiber, calcium carbonate, silica, kaolin, barium sulfate and the like.

The thermoplastic resin composition of the present invention may contain only one kind of these fiber reinforced materials (D), or may contain two or more kinds.
Further, in order to further improve the mechanical strength of the obtained molded product, these fiber reinforcing materials (D) may be surface-treated with a coupling agent such as a silane type, an epoxy type or a titanate type.

[Content of each component]
The content of the thermoplastic polyester resin (A) in the thermoplastic resin composition of the present invention is that of the thermoplastic polyester resin (A), the vinyl-based copolymer (B) and the epoxy-modified vinyl-based copolymer (C). It is 70 to 95 parts by mass, preferably 65 to 93 parts by mass, and more preferably 60 to 90 parts by mass with respect to 100 parts by mass in total.
The content of the vinyl-based copolymer (B) in the thermoplastic resin composition of the present invention is the thermoplastic polyester resin (A), the vinyl-based copolymer (B), and the epoxy-modified vinyl-based copolymer (C). It is 1 to 30 parts by mass, preferably 2 to 25 parts by mass, and more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the total.
The content of the epoxy-modified vinyl-based copolymer (C) in the thermoplastic resin composition of the present invention is the thermoplastic polyester resin (A), the vinyl-based copolymer (B), and the epoxy-modified vinyl-based copolymer (the epoxy-modified vinyl-based copolymer (C). It is 0.1 to 15 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the total of C).
The content of the fiber reinforcing material (D) in the thermoplastic resin composition of the present invention is the content of the thermoplastic polyester resin (A), the vinyl-based copolymer (B), and the epoxy-modified vinyl-based copolymer (C). It is 1 to 50 parts by mass, preferably 5 to 47 parts by mass, and more preferably 10 to 45 parts by mass with respect to 100 parts by mass in total.

When the content of each component is within the above range, the warpage property and mechanical property, particularly the weld property, of the obtained molded product are good.

[Other ingredients]
The thermoplastic resin composition of the present invention contains other than the thermoplastic polyester resin (A), the vinyl-based copolymer (B), and the epoxy-modified vinyl-based copolymer (C) to the extent that the effects of the present invention are not impaired. Other resins can be blended. Specific examples of other resins that can be blended include polycarbonate resin, polyvinyl chloride resin, polyacetal resin, modified polyphenylene ether (modified PPE) resin, ethylene-vinyl acetate copolymer, polyallylate resin, polyethylene resin, and polypropylene. One type or two or more types of resin, fluororesin, polyamide resin and the like can be mentioned.
However, when these other resins are blended, the present invention comprises a thermoplastic polyester resin (A), a vinyl-based copolymer (B), and an epoxy-modified vinyl-based copolymer (C) in a predetermined ratio. From the viewpoint of surely obtaining the effect, the content of the other resin is 100 parts by mass in total of the thermoplastic polyester resin (A), the vinyl-based copolymer (B) and the epoxy-modified vinyl-based copolymer (C). It is preferably 20 parts by mass or less.

Various additives may be added to the thermoplastic resin composition of the present invention, if necessary. Additives include antioxidants such as hindered phenol-based, sulfur-containing organic compound-based and phosphorus-containing organic compound-based, heat stabilizers such as phenol-based and acrylate-based, monostearyl acid phosphate and distearyl acid phos. Ester exchange inhibitors such as compounds of compounds, UV absorbers such as benzotriazoles, benzophenones and salicylates, various stabilizers such as light stabilizers such as organic nickels and hindered amines, metal salts of higher fatty acids, Lubricants such as higher fatty acid amides, plasticizers such as phthalates and phosphate esters, halogen-containing compounds such as polybromodiphenyl ether, tetrabromobisphenol-A, brominated epoxy oligomers and brominated polycarbonate oligomers, phosphorus-based Examples thereof include compounds, flame retardant / flame retardant aids such as antimony trioxide, carbon black, titanium oxide, pigments and dyes.

[Manufacturing method of thermoplastic resin composition]
The thermoplastic resin composition of the present invention comprises the above-mentioned thermoplastic polyester resin (A), vinyl-based copolymer (B), epoxy-modified vinyl-based copolymer (C), fiber reinforcing material (D), and, if necessary. It can be obtained by mixing other components used accordingly. For mixing these components, for example, a known kneading device such as an extruder, a roll, a Banbury mixer, or a kneader is used.

Mixing order and method of thermoplastic polyester resin (A), vinyl-based copolymer (B), epoxy-modified vinyl-based copolymer (C), fiber reinforced material (D), and other components used as necessary. Has no restrictions. In melt-kneading, it is preferable to melt-knead at 180 to 300 ° C. using various known extruders.

〔Molding〕
The molded article of the present invention is molded using the thermoplastic resin composition of the present invention. The molding method is not limited in any way. Examples of the molding method include an injection molding method, an extrusion molding method, a compression molding method, an insert molding method, a vacuum molding method, a blow molding method and the like.

The molded product obtained by molding the thermoplastic resin composition of the present invention is excellent in warpage property, mechanical property, particularly weld strength.

The molded product of the present invention is suitably used for a wide variety of applications such as electrical and electronic equipment parts, automobile parts, packaging materials such as bottles, building materials, daily necessities, household electrical appliances and office equipment parts, and in particular, a junction box. It is suitably used for harnesses, ECU housings, automobile lamp parts, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
Unless otherwise specified, "%" and "part" in the following examples are based on mass.
Glycidyl methacrylate is abbreviated as "GMA", acrylonitrile is abbreviated as "AN", styrene is abbreviated as "ST", and t-dodecyl mercaptan is abbreviated as "TDM".

[Evaluation / measurement method]
Various measurement and evaluation methods in the following production examples, examples and comparative examples are as follows.

<Measurement of epoxy equivalent>
The epoxy equivalent (g / eq.) Was measured for the epoxy-modified vinyl copolymer (C) according to JIS K 7236: 2009.

<Weight average molecular weight Mw, molecular weight distribution Mw / Mn>
Using GPC (GPC: "GPC / V2000" manufactured by Waters, column: "Shodex AT-G + AT-806MS" manufactured by Showa Denko), the weight average molecular weight Mw and the molecular weight distribution Mw / Mn in terms of polystyrene were measured. ..

<Reduced viscosity>
The reduced viscosity of the N, N-dimethylformamide solution prepared so that the concentration of the epoxy-modified vinyl copolymer (C) was 0.2 dL / g at 25 ° C. using an Ubbelohde viscometer: ηsp / C ( Unit: dL / g) was measured.

<Differential Scanning Calorimetry (DSC)>
Using a differential scanning calorimetry (DSC) (“DSC8230” manufactured by Rigaku Co., Ltd.), measurement was carried out in a temperature range of 10 ° C./min and an atmosphere of Air50 ml / min in the range of 30 ° C. to 300 ° C. In the differential scanning calorimetry chart obtained by this measurement, the presence or absence of heat absorption behavior at a measurement temperature of 100 ° C. to 120 ° C. and the presence or absence of heat generation behavior at a measurement temperature of 280 ° C. to 300 ° C. were observed.

<Evaluation of warpage characteristics>
A corner of a flat plate (size: 100 mm × 100 mm) having a thickness of 1 mm was suppressed, the height of the warped portion was measured, and the value having the largest warp amount among the flat plates was defined as the warp amount of the molded product. The smaller the value of the amount of warpage, the better the warp characteristics.
In Tables 2 and 3 below, the ratio to the warp amount of Comparative Example 1 ({(warp amount of Comparative Example 1-warp amount of the example) / warp amount of Comparative Example 1} × 100) is calculated, and the warp is calculated. The improvement rate was used.

<Measurement of tensile strength>
The tensile strength (MPa) was measured under the conditions of 23 ° C. and a tensile speed of 5.0 mm / min according to ASTM D638. The higher the number, the better.
For the tensile strength, the tensile strength of the non-welded portion and the tensile strength of the welded portion are measured, and the ratio of the tensile strength of the welded portion to the tensile strength of the non-welded portion ((tensile strength of the welded portion / tensile strength of the non-welded portion) × 100) was calculated as the tensile strength retention rate.

[Production Example 1: Production of Vinyl Copolymer (B)]
120 parts of distilled water, 0.4 parts of tricalcium phosphate, 0.03 parts of Demol P (maleate high molecular weight surfactant manufactured by Kao Co., Ltd.), 25 parts of styrene, 75 parts of acrylonitrile, 2,2'-azobisiso 0.3 part of butylonitrile and 0.25 part of t-dodecyl mercaptan were charged in a reaction vessel, and the mixture was stirred and suspended. Then, the temperature was raised, and polymerization was started when the internal temperature reached 77 ° C. After confirming the polymerization exothermic peak with a thermometer, it was held at an internal temperature of 95 ° C. for 120 minutes. Then, it was cooled, and the obtained slurry-like product was filtered, washed with water, and dried to obtain a bead-shaped vinyl-based copolymer (B). The weight average molecular weight Mw of this vinyl-based copolymer (B) was 110,000.

[Production Example 2: Production of Epoxy Modified Vinyl Copolymer (C)]
<Manufacturing of epoxy-modified vinyl copolymer (C-1)>
0.045 parts of the polymer dispersant and 0.5 part of sodium sulfate were charged into 150 parts of distilled water in a reaction vessel and stirred. A mixture of 8.5 parts of glycidyl methacrylate, 22.9 parts of acrylonitrile, 68.6 parts of styrene, 0.25 parts of t-dodecyl mercaptan, and 0.18 parts of 2,2'-azobis (2-methylbutyronitrile). Was added to form a suspension, the temperature was raised, and polymerization was started when the internal temperature reached 77 ° C. After confirming the polymerization exothermic peak with a thermometer, it was held at an internal temperature of 95 ° C. for 120 minutes. Then, it was cooled, and the obtained slurry-like product was filtered, washed with water, and dried to obtain a bead-shaped epoxy-modified vinyl-based copolymer (C-1).

<Manufacturing of epoxy-modified vinyl copolymer (C-2)>
A beaded epoxy-modified vinyl copolymer (C-2) was produced in the same manner as in the production of the epoxy group-containing vinyl monomer (C-1) except that the number of parts of t-dodecyl mercaptan was changed to 0.80. ) Was obtained.

Table 1 shows the measured values of the weight average molecular weight Mw, the molecular weight distribution Mw / Mn, the reduced viscosity, and the epoxy equivalent of the epoxy-modified vinyl copolymers (C-1) and (C-2).
Further, in differential scanning calorimetry (DSC), the epoxy-modified vinyl copolymers (C-1) and (C-2) have heat absorption behavior between the measurement temperatures of 90 ° C. to 120 ° C., and the measurement temperatures of 260 ° C. to 300 ° C. It was confirmed that the heat generation behavior was exhibited during the temperature. The DSC charts of the epoxy-modified vinyl copolymers (C-1) and (C-2) are shown in FIG.

[Other materials used]
As the thermoplastic polyester resin (A), other resin and the fiber reinforced material (D), the following were used.

<Thermoplastic polyester resin (A)>
Polybutylene terephthalate "Juranex 2000" manufactured by Polyplastics Co., Ltd.

<Epoxy resin (X)>
Epoxy resin "JER1004AF" manufactured by Mitsubishi Chemical Corporation
(The epoxy resin (X) does not contain a vinyl monomer unit and is different from the epoxy-modified vinyl copolymer (C).)

<Fiber reinforced plastic (D)>
Glass fiber "ESC 03T-187" manufactured by Nippon Electric Glass Co., Ltd.

[Examples 1 to 9, Comparative Examples 1 to 4]
<Melting kneading>
Table 2 shows the thermoplastic polyester resin (A), vinyl copolymer (B), epoxy-modified vinyl copolymer (C-1), and (C-2) (epoxy resin (X) in Comparative Example 4). Add and mix according to the formulation shown in 3, melt-knead with a twin-screw extruder (equipment: KTX30, cylinder temperature: 250 ° C., screw rotation speed: 250 rpm), pelletize the obtained strands, and prepare a thermoplastic resin composition. Pellets were obtained.

<Injection molding 1>
Pellets of the obtained thermoplastic resin composition are applied to both ends in the length direction by an injection molding machine (“IS55FP-1.5A” manufactured by Toshiba Machine Co., Ltd.) under the conditions of a cylinder temperature of 220 to 250 ° C. and a mold temperature of 60 ° C. A tensile test piece having a gate and a weld in the center was prepared.

<Injection molding 2>
The obtained pellets of the thermoplastic resin composition are molded by an injection molding machine ("JSW" manufactured by Japan Steel Works, Ltd.) under the conditions of a cylinder temperature of 280 ° C. and a mold temperature of 70 ° C. and a thickness of 1 mm and a size of 100 mm x 100 mm. Was prepared and used as a flat plate for measuring the amount of warpage.

The evaluation results are shown in Tables 2 and 3.

From Tables 2 and 3, the fiber reinforced material (D) is added to the resin component in which the thermoplastic polyester resin (A), the vinyl-based copolymer (B) and the epoxy-modified vinyl-based copolymer (C) are mixed in a predetermined ratio. According to the blended thermoplastic resin composition of the present invention, it can be seen that a molded product having high tensile strength, particularly the tensile strength of the weld portion and a small amount of warpage can be obtained.
On the other hand, in Comparative Examples 1 to 3 in which the vinyl-based copolymer (B) and / or the epoxy-modified vinyl-based copolymer (C) was not blended, both the maintenance of the tensile strength of the weld portion and the suppression of warpage were achieved. It is not possible.
In Comparative Example 4 in which the epoxy resin (X) is used instead of the epoxy-modified vinyl copolymer (C), the warp suppressing effect is not sufficient.

Claims (7)

A vinyl-based copolymer (B) containing 70 to 95 parts by mass of a thermoplastic polyester resin (A), an aromatic vinyl monomer unit and a vinyl cyanide monomer unit as constituent elements (however, an epoxy-modified vinyl-based copolymer). The thermoplastic polyester resin (A) contains 1 to 30 parts by mass (excluding (C)) and 0.1 to 15 parts by mass of the epoxy-modified vinyl-based copolymer (C) so as to have a total of 100 parts by mass. , A thermoplastic resin composition containing 1 to 50 parts by mass of the fiber reinforcing material (D) with respect to a total of 100 parts by mass of the vinyl-based copolymer (B) and the epoxy-modified vinyl-based copolymer (C). The epoxy-modified vinyl-based copolymer (C) is copolymerized with 0.1 to 95 parts by mass of an epoxy group-containing vinyl monomer unit, an aromatic vinyl monomer unit, a vinyl cyanide monomer unit, and the like. Contains 5-99.9 parts by mass of one or more vinyl monomer units selected from other possible vinyl monomer units (provided, epoxy group-containing vinyl monomer units and aromatic vinyl monomer units. , A total of 100 parts by mass of a vinyl cyanide monomer unit and one or more vinyl monomer units selected from other vinyl monomers copolymerizable therewith), the thermoplastic according to claim 1. Resin composition. The claim that the epoxy-modified vinyl-based copolymer (C) contains 4.1 to 99 parts by mass of an aromatic vinyl monomer unit and 0.9 to 95.8 parts by mass of a vinyl cyanide monomer unit. 2. The thermoplastic resin composition according to 2. The thermoplastic resin composition according to any one of claims 1 to 3, wherein the epoxy-modified vinyl copolymer (C) has a weight average molecular weight Mw of 50,000 to 300,000. The epoxy equivalent of the epoxy-modified vinyl copolymer (C) is 150 to 143,000 g / eq. The thermoplastic resin composition according to any one of claims 1 to 4. The epoxy-modified vinyl-based copolymer (C) uses differential scanning calorimetry (DSC) and has a measurement temperature of 90 ° C. to 90 ° C. under an atmosphere of a heating rate of 10 ° C./min and Air of 50 ml / min as measurement conditions. The thermoplastic resin composition according to any one of claims 1 to 5, wherein it can be observed that heat absorption behavior is exhibited at 120 ° C. and heat generation behavior is exhibited at a measurement temperature of 260 ° C. to 300 ° C. A molded product comprising the thermoplastic resin composition according to any one of claims 1 to 6.

Images