Epoxy group-containing vinyl copolymer, method for producing the same, thermoplastic resin composition, and molded article

Abstract

To provide an epoxy group-containing vinyl-based copolymer from which a thermoplastic resin composition that improves moldability and releasability of a thermoplastic resin such as a thermoplastic polyester resin, and has a good balance between flowability and impact resistance can be provided.SOLUTION: An epoxy group-containing vinyl-based copolymer (A) is a copolymer composed of at least 60 to 79.9 pts.wt. of an aromatic vinyl-based monomer (a1), 20 to 39.9 pts.wt. of a vinyl cyanide-based monomer (a2) and 0.1 to 5 pts.wt. of an epoxy group-containing vinyl-based monomer (a3) (total of (a1), (a2) and (a3) is 100 pts.wt.), and has a weight average molecular weight Mw in terms of polystyrene determined by GPC of 100,000 to 300,000, and a ratio Mw / Mn of the weight average molecular weight Mw to a number average molecular weight Mn of 2.5 to 3.5.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a thermoplastic resin composition having a good balance of fluidity and impact resistance, and excellent in moldability, mold release property, etc., by blending an epoxy group-containing vinyl copolymer with a thermoplastic resin such as a thermoplastic polyester resin, and a molded article thereof.

Background Art

[0002] Styrene resins typified by acrylonitrile-butadiene-styrene (ABS) resin are used in a wide range of fields including various parts of household electric appliances, automobiles, and OA equipment because they have excellent mechanical properties, molding processability, and electrical insulation properties. On the other hand, polyester resins such as polybutylene terephthalate (PBT) resin are widely used as materials for manufacturing various electric and electronic equipment parts, interior and exterior parts for vehicles such as automobiles, trains, and electric trains, and other general industrial products because they are excellent in electrical properties, chemical resistance, heat resistance, dimensional stability, etc. Many of these parts require good moldability for the resin used.

[0003] In recent years, the technology of polymer alloys, which mix a plurality of different polymers, has been studied as a means for improving the physical properties of polymer compounds. The purpose of polymer alloys is to obtain a polymer having the characteristics of each constituent polymer by mixing a plurality of different polymers.

[0004] In Patent Document 1, for the purpose of improving the molding processability, heat resistance, and hydrolysis resistance of a thermoplastic polyester resin, an epoxy-modified vinyl copolymer having a weight average molecular weight of 50,000 to 300,000 and a molecular weight distribution Mw / Mn of 1.9 to 2.4, which is obtained by copolymerizing glycidyl methacrylate and one or more monomers selected from aromatic vinyl monomers / cyanated vinyl monomers, is proposed. However, the mold release property has not been studied, and there are still problems with the mold release property.

[0005] Patent Document 2 proposes the formulation of a modifier consisting of aromatic vinyl monomer-based units and vinyl cyanide monomer-based units, or aromatic vinyl monomer-based units, vinyl cyanide monomer-based units, and other vinyl monomer-based units, with the aim of achieving both mechanical and thermal properties and dimensional stability in molded articles made from fiber-reinforced resin compositions. However, the compatibility when compounded with polyester is insufficient, leaving concerns about moldability and impact resistance of the molded articles. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Public Gazette No. 2018 / 043334 [Patent Document 2] Japanese Patent Publication No. 2019-210489 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to provide an epoxy group-containing vinyl copolymer that can improve the moldability and release properties of thermoplastic resins such as thermoplastic polyester resins, and provide a thermoplastic resin composition with a good balance of fluidity and impact resistance. The present invention also aims to provide a thermoplastic resin composition comprising this epoxy group-containing vinyl copolymer and a thermoplastic resin such as a thermoplastic polyester resin, and a molded article obtained by molding this thermoplastic resin composition. [Means for solving the problem]

[0008] The inventors have found that an epoxy group-containing vinyl copolymer obtained by copolymerizing an epoxy group-containing vinyl monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer in predetermined proportions, having a weight-average molecular weight Mw and molecular weight distribution Mw / Mn within a predetermined range, solves the above problem. The present invention has the following configuration: (1) At least 60 to 79.9 parts by weight of aromatic vinyl monomer (a1), 20 to 39.9 parts by weight of vinyl cyanide monomer (a2), and 0.1 to 0.9 parts by weight of epoxy group-containing vinyl monomer (a3) 3 An epoxy group-containing vinyl copolymer (A) obtained by polymerizing a vinyl monomer mixture (a) containing parts by weight (where the total of (a1), (a2), and (a3) ​​is 100 parts by weight), characterized in that the weight-average molecular weight Mw on a polystyrene basis determined by GPC is 100,000 to 300,000, and the ratio of weight-average molecular weight Mw to number-average molecular weight Mn, Mw / Mn, is 2.5 to 3.5. (2) The epoxy group-containing vinyl copolymer according to (1), characterized in that, in the cumulative elution weight obtained by GPC / FT-IR measurement of the epoxy group-containing vinyl copolymer (A), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of less than 30% when cumulatively accumulated from the low molecular weight side of the copolymer is (I), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 30% or more but less than 70% when cumulatively accumulated from the low molecular weight side of the copolymer is (II), and the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 70% or more when cumulatively accumulated from the low molecular weight side of the copolymer is (III), the composition distribution of the epoxy group-containing vinyl monomer units is (I) < (II) and (III) < (II). (3) An epoxy group-containing vinyl copolymer according to (1) or (2), wherein the melt flow rate at 220°C and a load of 10,000 g is 15 to 32 g / 10 min. ( 4 ) A method for producing an epoxy group-containing vinyl copolymer (A), characterized in that a copolymer is obtained by polymerizing a vinyl monomer mixture (a) containing at least 60 to 79.9 parts by weight of an aromatic vinyl monomer (a1), 20 to 39.9 parts by weight of a cyanide vinyl monomer (a2), and 0.1 to 5 parts by weight of an epoxy group-containing vinyl monomer (a3), wherein the total of (a1), (a2), and (a3) ​​is 100 parts by weight, and the weight-average molecular weight Mw on a polystyrene basis, as determined by GPC, is 100,000 to 300,000, and the ratio of weight-average molecular weight Mw to number-average molecular weight Mn, Mw / Mn, is 2.5 to 3.5. A method for producing an epoxy group-containing vinyl copolymer, characterized by suspend polymerization of the vinyl monomer mixture (a) using two or more mercaptan-based chain transfer agents. ( 5 ) The method for producing an epoxy group-containing vinyl copolymer according to (4), characterized in that, in the cumulative elution weight obtained by GPC / FT-IR measurement of the epoxy group-containing vinyl copolymer (A), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of less than 30% when cumulatively accumulated from the low molecular weight side of the copolymer is (I), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 30% or more but less than 70% when cumulatively accumulated from the low molecular weight side of the copolymer is (II), and the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 70% or more when cumulatively accumulated from the low molecular weight side of the copolymer is (III), the composition distribution of the epoxy group-containing vinyl monomer units is (I) < (II) and (III) < (II). ( 6) Among the mercaptan-based chain transfer agents, at least one is n-octyl mercaptan, characterized in that ( 4) or (5) The method for producing an epoxy group-containing vinyl-based copolymer according to 4) or (5) . ( 7 ) (1)~( 3) A thermoplastic resin composition comprising an epoxy group-containing vinyl-based copolymer (A) according to any one of 3) and a thermoplastic resin (B). ( 8 ) The thermoplastic resin (B) contains a thermoplastic polyester resin (C) ( 7) The thermoplastic resin composition according to 7) . ( 9 ) The epoxy group-containing vinyl-based copolymer (A) is contained in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the thermoplastic resin (B), ( 7) or (8) The thermoplastic resin composition according to 7) or (8) . ( 10 )( 7)~(9) A molded article comprising the thermoplastic resin composition according to any one of 7)~(9) .

Advantages of the Invention

[0009] When the epoxy group-containing vinyl-based copolymer of the present invention is used, it is possible to improve the moldability and脱模性 of thermoplastic resins such as thermoplastic polyester resins, and to provide a thermoplastic resin composition having a good balance of fluidity and impact resistance.

Brief Description of the Drawings

[0010] [Figure 1] It is the appearance of the box-shaped molded article used for the moldability evaluation in Examples and Comparative Examples. [Figure 2] It is a schematic side view (1) and a schematic plan view (2) of FIG. 1.

Modes for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail.

[0012] 〈Epoxy Group-Containing Vinyl-Based Copolymer (A)〉 The epoxy group-containing vinyl copolymer (A) of the present invention is obtained by copolymerizing a vinyl monomer mixture (a) containing an aromatic vinyl monomer (a1), a vinyl cyanide monomer (a2), and an epoxy group-containing vinyl monomer (a3). Such a copolymer can be preferably used as a compatibilizer with a thermoplastic polyester resin, improves the moldability and releasability of a thermoplastic resin containing a thermoplastic polyester resin, etc., and can provide a thermoplastic resin composition having a good balance between fluidity and impact resistance.

[0013] Examples of the aromatic vinyl monomer (a1) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, ethylstyrene, vinyltoluene, vinylxylene, methyl-α-methylstyrene, t-butylstyrene, divinylbenzene, 1,1-diphenylstyrene, N,N-diethyl-p-aminomethylstyrene, N,N-diethyl-p-aminoethylstyrene, vinylnaphthalene, vinylpyridine, chlorinated styrenes such as monochlorostyrene and dichlorostyrene; brominated styrenes such as monobromostyrene and dibromostyrene; monofluorostyrene, etc. Among them, styrene and α-methylstyrene are preferred. These aromatic vinyl monomers can be used alone or in combination of two or more.

[0014] [[ID=�]] Examples of the vinyl cyanide monomer (a2) include acrylonitrile, methacrylonitrile, ethacrylonitrile, fumaronitrile, etc. Among them, acrylonitrile is preferred. These vinyl cyanide monomers can be used alone or in combination of two or more.

[0015] As the epoxy group-containing vinyl monomer (a3), a (meth)acrylic ester monomer having an epoxy group is preferred, and examples thereof include epoxy group-containing methacrylates such as glycidyl methacrylate, and epoxy group-containing acrylates such as glycidyl acrylate. Two or more of these may be used. Among them, glycidyl methacrylate is preferred.

[0016] Furthermore, the vinyl monomer mixture (a) may also contain vinyl monomers other than the aromatic vinyl monomer (a1), vinyl cyanide monomer (a2), and epoxy group-containing vinyl monomer (a3), to the extent that the effects of the present invention are not impaired. Examples of vinyl monomers other than (a1) to (a3) ​​include unsaturated carboxylate alkyl ester monomers and acrylamide monomers. Two or more of these may be used.

[0017] There are no particular restrictions on the unsaturated carboxylate alkyl ester monomer, but esters of an alcohol having 1 to 6 carbon atoms with acrylic acid or methacrylic acid are preferred. Examples of esters of an alcohol having 1 to 6 carbon atoms with acrylic acid or methacrylic acid include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, n-hexyl (meth)acrylate, and cyclohexyl (meth)acrylate, with methyl (meth)acrylate being preferred. Note that "(meth)acrylic acid" refers to acrylic acid or methacrylic acid.

[0018] Examples of acrylamide monomers include acrylamide, methacrylamide, and N-methylacrylamide.

[0019] The content of epoxy group-containing vinyl monomers in the epoxy group-containing vinyl copolymer (A) is 0.1 to 5 parts by weight, more preferably 0.2 to 4 parts by weight, and particularly preferably 0.3 to 3 parts by weight. If the content of epoxy group-containing vinyl monomers in the epoxy group-containing vinyl copolymer (A) is less than 0.1 parts by weight, the compatibility when mixed with polyester resin decreases, and the impact resistance of the molded article made from the thermoplastic resin composition containing polyester resin decreases. If the content of epoxy group-containing vinyl monomers in the epoxy group-containing vinyl copolymer (A) exceeds 5 parts by weight, the epoxy group content increases, making it easier for crosslinks to form due to excessive reaction between the epoxy group-containing vinyl copolymer and polyester resin, and reducing the fluidity of the thermoplastic resin composition containing styrene resin and polyester resin, as well as the impact resistance and surface gloss of the molded article made from the thermoplastic resin composition.

[0020] The vinyl monomer components in the epoxy group-containing vinyl copolymer (A), excluding the epoxy group-containing vinyl monomer, are aromatic vinyl monomers and vinyl cyanide monomers. The total content of the vinyl monomer components excluding the epoxy group-containing vinyl monomer in the epoxy group-containing vinyl copolymer (A) is 95 to 99.9 parts by weight, more preferably 70 to 99.9 parts by weight, and particularly preferably 85 to 99.9 parts by weight. If the content of these vinyl monomers exceeds 99.9 parts by weight, the compatibility with polyester resin decreases, and the impact resistance of the molded article made from the thermoplastic resin composition containing polyester resin decreases. If the content of these vinyl monomers is less than 95 parts by weight, the fluidity of the resulting thermoplastic resin composition and the impact resistance and surface gloss of the molded article made from the thermoplastic resin composition decrease.

[0021] In the present invention, the content of each vinyl monomer in the epoxy group-containing vinyl copolymer (A) refers to the content when the total of the epoxy group-containing vinyl monomer, aromatic vinyl monomer, and vinyl cyanide monomer is 100 parts by weight. The content of vinyl monomers in the epoxy group-containing vinyl copolymer (A) refers to the content of constituent units derived from the vinyl monomer that constitutes the epoxy group-containing vinyl copolymer (A), and usually corresponds to the content of each vinyl monomer in 100 parts by weight of a mixture of the epoxy group-containing vinyl monomer, aromatic vinyl monomer, and vinyl cyanide monomer, which are copolymerization raw materials when producing the epoxy group-containing vinyl copolymer (A).

[0022] The content of aromatic vinyl monomer (a1) in the epoxy group-containing vinyl copolymer (A) is preferably 60 to 79.9 parts by weight, more preferably 65 to 79 parts by weight, and particularly preferably 70 to 78 parts by weight. If the content of aromatic vinyl monomer is less than 60 parts by weight, the compatibility with polyester resin decreases when mixed, and the impact resistance of the molded article made from the thermoplastic resin composition containing polyester resin decreases. If the content of aromatic vinyl monomer exceeds 80 parts by weight, the compatibility with polyester resin also decreases, and the impact resistance of the molded article made from the thermoplastic resin composition containing polyester resin decreases.

[0023] The content of vinyl cyanide monomer (a2) in the epoxy group-containing vinyl copolymer (A) is preferably 20 to 39.9 parts by weight, more preferably 21 to 35 parts by weight, and particularly preferably 22 to 30 parts by weight. If the content of vinyl cyanide monomer is less than 20 parts by weight, the compatibility with polyester resin decreases, and the impact resistance of the molded article made from the thermoplastic resin composition containing polyester resin decreases. If the content of vinyl cyanide monomer exceeds 39.9 parts by weight, the compatibility with polyester resin decreases, the impact resistance of the molded article made from the thermoplastic resin composition containing polyester resin decreases, and the molded article becomes more yellowish.

[0024] The weight-average molecular weight Mw of the epoxy-modified vinyl copolymer (A) of the present invention is 100,000 to 300,000, preferably 120,000 to 270,000. Having the weight-average molecular weight Mw within this range improves the moldability and release properties of the thermoplastic resin composition containing this epoxy-containing vinyl copolymer (A), and provides a thermoplastic resin composition with a good balance of fluidity and impact resistance. Here, the weight-average molecular weight Mw is the polystyrene-equivalent molecular weight determined by gel permittance chromatography.

[0025] The molecular weight distribution Mw / Mn of the epoxy group-containing vinyl copolymer (A) of the present invention is preferably 2.5 to 3.5, more preferably 2.5 to 3.4. Having a molecular weight distribution Mw / Mn within this range improves the moldability and release properties of the thermoplastic resin composition containing this epoxy group-containing vinyl copolymer (A), and provides a thermoplastic resin composition with a good balance of fluidity and impact resistance.

[0026] The weight-average molecular weight Mw and molecular weight distribution Mw / Mn of the epoxy group-containing vinyl copolymer (A) are measured by the method described in the Examples section below.

[0027] Means for adjusting the weight-average molecular weight Mw and molecular weight distribution Mw / Mn of the epoxy group-containing vinyl copolymer (A) to the above range include adjusting the amount of chain transfer agent and polymerization initiator added to the preferred range described later.

[0028] In the integrated elution weight obtained by GPC / FT-IR of the epoxy group-containing vinyl copolymer (A) of the present invention, the average concentration of the epoxy group-containing vinyl monomer units at less than 30% of the integrated value calculated from the low molecular weight side of the copolymer is defined as (I), and the average concentration of the epoxy group-containing vinyl monomer units at 30% or more and less than 70% of the integrated value calculated from the low molecular weight side of the copolymer is defined as (II), and the average concentration of the epoxy group-containing vinyl monomer units at 70% or more of the integrated value calculated from the low molecular weight side of the copolymer is defined as (III). Then, the composition distribution of the epoxy group-containing vinyl monomer units is such that (I) < (II) and (III) < (II). Here, the average concentration of the epoxy group-containing vinyl monomer units refers to the arithmetic mean of the concentrations of the epoxy group-containing vinyl monomer units in each molecular weight region. Further, from the viewpoint of improving the accuracy of the average concentration of the epoxy group-containing vinyl monomer units, the number of concentration measurement points of the epoxy group-containing vinyl monomer units in each molecular weight region is preferably 30 or more, and more preferably 35 or more. In addition, when the molecular weight at which the concentration of the epoxy group-containing vinyl monomer units reaches the peak value is M1, the molecular weight at which the integrated value calculated from the low molecular weight side is 30% by mass is M2, and the molecular weight at which the integrated value calculated from the low molecular weight side is 70% by mass is M3, then M2 < M1 < M3. Here, the peak value referred to herein means the apex when the plot of the concentration of the epoxy group-containing vinyl monomer units against the polystyrene-equivalent molecular weight is subjected to regression analysis with a quadratic function. The epoxy group-containing vinyl copolymer (A) reacts and binds with the epoxy group and the functional groups remaining in the thermoplastic polyester resin, and imparts compatibility by introducing vinyl monomer units into the thermoplastic polyester resin. Therefore, in the region below the molecular weight at which the integrated value calculated from the low molecular weight side is 30% by mass, the number of vinyl monomer units is relatively small, so the compatibility with the thermoplastic polyester resin is poor. On the contrary, in the region above the molecular weight at which the integrated value calculated from the low molecular weight side is 70% by mass, the molecular weight after binding to the thermoplastic polyester resin is relatively large and the fluidity is poor. Therefore, by setting M2 < M1 < M3, high levels of compatibility and fluidity with the thermoplastic polyester resin can be achieved simultaneously.

[0029] The aforementioned compositional distribution can be measured by the following method. 0.1 g of epoxy group-containing vinyl copolymer (A) was dissolved in 50 g of chloroform to prepare a solution of approximately 0.2% by weight. From the GPC chromatogram obtained by eluent evaporation type GPC / FT-IR under the following conditions, the molecular weight distribution and weight-average molecular weight were calculated using polystyrene as the standard substance. Simultaneously, the concentration derived from the epoxy group-containing vinyl monomer at each molecular weight was calculated from the absorption peak heights obtained by FT-IR measurement. Column: TSKgelGMHHR-M (2 pieces) (Manufactured by Tosoh) Solvent: Chloroform Flow rate: 1.0mL / min Measurement interval: 30 times / min Column temperature: 23℃ Differential refractive index detector: RI8020 type (manufactured by Tosoh) Infrared absorption spectrometer: Nicoleti S50 (manufactured by Thermo Fisher) Resolution: 4cm -1 Total number of times: 16.

[0030] Means for adjusting the concentration of epoxy group-containing vinyl monomer units to the molecular weight distribution of epoxy group-containing vinyl copolymer (A) to the above range include adjusting the amount of chain transfer agent or polymerization initiator added to the preferred range described later.

[0031] The epoxy group-containing vinyl copolymer (A) of the present invention can be obtained by copolymerizing the vinyl monomer mixture (a) using known polymerization methods such as bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Among these, suspension polymerization is preferred because polymerization control is easy and no steps are required to remove unreacted components, reaction solvents, emulsifiers, etc.

[0032] In the method for producing the epoxy group-containing vinyl copolymer (A), a polymerization initiator may be used. Examples of polymerization initiators include peroxides, azo compounds, and persulfates. Two or more of these may be used. Redox-type polymerization initiators can also be used.

[0033] Specific examples of peroxides include benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl isopropyl carbonate, di-t-butyl peroxide, t-butyl peroctate, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, and t-butylperoxy-2-ethylhexanoate.

[0034] Specific examples of azo compounds include 2,2'-azobisisobutyronitrile, azobis(2,4-dimethylvaleronitrile), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2-cyano-2-propylazoformamide, 1,1'-azobiscyclohexane-1-carbonnitrile, azobis(4-methoxy-2,4-dimethylvaleronitrile), dimethyl2,2'-azobisisobutyrate, 1-t-butylazo-2-cyanobutane, and 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane.

[0035] Specific examples of persulfates include potassium persulfate, sodium persulfate, and ammonium persulfate.

[0036] Among these, 2,2'-azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) are preferred.

[0037] The amount of polymerization initiator added is preferably 0.1 to 0.5 parts by weight per 100 parts by weight of the total amount of vinyl monomer mixture (a).

[0038] In a method for producing an epoxy group-containing vinyl copolymer (A), it is preferable to use a chain transfer agent, which allows the weight-average molecular weight of the epoxy group-containing vinyl copolymer to be adjusted to a desired range. Mercaptans are preferred as chain transfer agents, and specific examples include n-octyl mercaptan, t-dodecyl mercaptan, n-tetradecyl mercaptan, n-octadecyl mercaptan, etc. It is preferable to use two or more of these. Among these, n-octyl mercaptan and t-dodecyl mercaptan are preferred.

[0039] The amount of chain transfer agent added is preferably 0.01 to 1.0 part by weight per 100 parts by weight of the total amount of vinyl monomer mixture (a). By using 0.01 part by weight or more of the chain transfer agent, the weight-average molecular weight of the epoxy group-containing vinyl copolymer can be easily adjusted to 300,000 or less. On the other hand, by using 1.0 part by weight or less of the chain transfer agent, the weight-average molecular weight of the epoxy group-containing vinyl copolymer can be easily adjusted to 100,000 or more.

[0040] When producing an epoxy group-containing vinyl copolymer (A) by suspension polymerization, it is preferable to use a suspension stabilizer. Examples of suspension stabilizers include inorganic suspension stabilizers such as clay, barium sulfate, and magnesium hydroxide, and organic suspension stabilizers such as polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, polyacrylamide, and methyl methacrylate / acrylamide copolymer. Two or more of these may be used. Among these, organic suspension stabilizers are preferred in terms of color stability.

[0041] Generally, suspension polymerization involves dispersing monomers, in which a polymerization initiator is dissolved, in an aqueous medium containing a suspension stabilizer, and generating radicals to carry out polymerization. The monomer components may be added all at once at the beginning, or some or all of the monomer components may be added continuously or intermittently.

[0042] A slurry of epoxy group-containing vinyl copolymer (A) is obtained by suspension polymerization, and then, after dehydration and drying, bead-shaped epoxy group-containing vinyl copolymer is obtained.

[0043] Examples of thermoplastic resins (B) included in the thermoplastic resin composition of the present invention include thermoplastic polyester resins (C), ABS resin, ASA resin, AES resin, polycarbonate, polyvinyl chloride, polystyrene, polyacetal, modified polyphenylene ether (modified PPE), ethylene-vinyl acetate copolymer, polyarylate, liquid crystal polyester, polyethylene, polypropylene, fluororesin, and polyamide. The thermoplastic resin composition of the present invention may contain one of these thermoplastic resins (C), or it may contain two or more.

[0044] Of these thermoplastic resins (B), the thermoplastic resin composition of the present invention preferably contains the thermoplastic polyester resin (C) described below as thermoplastic resin (B).

[0045] If a thermoplastic resin other than thermoplastic polyester resin (C), such as ABS resin, is used in combination with thermoplastic polyester resin (C), an improvement in mechanical strength, such as impact resistance, can be achieved.

[0046] When the thermoplastic resin composition of the present invention contains a thermoplastic polyester resin (C) and a thermoplastic resin other than the thermoplastic polyester resin (C) (B), it is preferable that the content of the thermoplastic resin other than the thermoplastic polyester resin (C) be 150 parts by weight or less per 100 parts by weight of the thermoplastic polyester resin (C) in order to reliably obtain the effects of using the thermoplastic polyester resin (C).

[0047] In the present invention, the thermoplastic polyester resin (C) refers to a resin having ester bonds in its main chain, and includes polymers of dicarboxylic acid or its ester-forming derivative and glycol, and polymers of monomers having carboxyl groups and hydroxyl groups in the molecule. Examples include polybutylene terephthalate (PBT) resin, polyethylene terephthalate (PET) resin, and polylactic acid (PLA) resin. By including the thermoplastic polyester resin (C) in the epoxy group-containing vinyl copolymer of the present invention, it is possible to improve the release properties and moldability of the thermoplastic resin composition and provide a thermoplastic resin composition with a good balance of fluidity and impact resistance.

[0048] The thermoplastic resin composition of the present invention comprises the epoxy group-containing vinyl copolymer (A) of the present invention and a thermoplastic resin (B) such as the thermoplastic polyester resin (C) described above.

[0049] The thermoplastic resin composition of the present invention may contain only one type of epoxy group-containing vinyl copolymer (A) of the present invention, or it may contain two or more types of copolymer components with different types, compositions, weight-average molecular weights (Mw), etc. Furthermore, the thermoplastic resin composition of the present invention may contain only one type of thermoplastic resin (B), such as the thermoplastic polyester resin (C) described above, or it may contain two or more types.

[0050] The content of the epoxy group-containing vinyl copolymer (A) in the thermoplastic resin composition of the present invention is preferably 0.1 to 50 parts by weight, particularly 1 to 45 parts by weight, per 100 parts by weight of thermoplastic resin (B). If the content of the epoxy group-containing vinyl copolymer (A) per 100 parts by weight of thermoplastic resin (B) is less than 0.1 parts by weight, the compatibility of the thermoplastic resin (B), such as thermoplastic polyester resin (C), with the polyester resin decreases due to the epoxy-modified vinyl copolymer (A), and the impact resistance of the molded article made from the thermoplastic resin composition containing the polyester resin decreases. If the content of the epoxy-modified vinyl copolymer (A) per 100 parts by weight of thermoplastic resin (C) exceeds 50 parts by weight, the epoxy group content increases, making it easier for crosslinks to form due to excessive reaction between the epoxy group-containing vinyl copolymer and the polyester resin, and the fluidity of the thermoplastic resin composition containing the styrene resin and the polyester resin, as well as the impact resistance and surface gloss of the molded article made from the thermoplastic resin composition, decreases.

[0051] The thermoplastic resin composition of the present invention may contain other resins, elastomers, etc., other than the epoxy group-containing vinyl copolymer (A) and thermoplastic resin (B), as long as the effects of the present invention are not impaired.

[0052] Furthermore, the thermoplastic resin composition of the present invention may, if necessary and without impairing the objectives of the present invention, further contain inorganic fillers such as glass fibers, glass powder, glass beads, glass flakes, alumina, alumina fibers, carbon fibers, graphite fibers, stainless steel fibers, silicon carbide whiskers, potassium titanate fibers, warlastenite, asbestos, hard clay, calcined clay, talc, kaolin, mica, calcium carbonate, magnesium carbonate, aluminum oxide, and minerals; antioxidants such as hindered phenolic compounds, sulfur-containing compounds, and phosphorus-containing organic compounds; heat stabilizers such as phenolic compounds and acrylates; ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, and salicylates; hindered amine light stabilizers; lubricants and plasticizers such as higher fatty acids, acid ester compounds, acid amide compounds, and higher alcohols. The product may contain one or more additives such as carbon acid and its salts, esters thereof, half-esters thereof, mold release agents such as stearyl alcohol, stearamide, and ethylene wax, flame retardant aids, color inhibitors such as phosphates and hypophosphates, neutralizing agents such as phosphoric acid, monosodium phosphate, maleic anhydride, and succinic anhydride, nucleating agents, antistatic agents such as amine-based, sulfonic acid-based, and polyether-based agents, and colorants such as carbon black, pigments, and dyes.

[0053] Next, a method for producing the thermoplastic resin composition of the present invention will be described. The thermoplastic resin composition of the present invention can be produced, for example, by mixing an epoxy group-containing vinyl copolymer (A), a thermoplastic polyester resin (C), and other components as needed using a mixer, or by melt-kneading using a melt-kneader. Examples of mixers include V-type blenders, super mixers, super floaters, and Henschel mixers. Examples of melt-kneaders include kneaders, single-screw and twin-screw extruders. Generally, a method is preferred in which each component is pre-mixed using a mixer, and the pre-mixed mixture is uniformly melt-kneaded using a melt-kneader. The melt-kneading temperature is preferably 230 to 300°C, more preferably 250 to 285°C. After melt-kneading, it is common to pelletize the mixture using a pelletizer.

[0054] The thermoplastic resin composition of the present invention can be molded by any molding method used for molding thermoplastic resin compositions and used as a molded article of any shape. Examples of molding methods include injection molding, extrusion molding, blow molding, vacuum molding, compression molding, and gas-assisted molding. Examples of molded article shapes include injection molded articles such as automobile parts, electrical and electronic equipment parts, films, sheets, television frames, bases, and cosmetic containers. [Examples]

[0055] The present invention will be described in detail below with reference to examples and comparative examples, but this will not limit the present invention. First, the methods for measuring and evaluating various properties in the examples and comparative examples will be described. Hereinafter, "%" and "parts" refer to weight unless otherwise specified.

[0056] (1) Weight average molecular weight Mw, Mw / Mn Approximately 0.03 g of each sample of epoxy group-containing vinyl copolymer (A) obtained in each example and comparative example was dissolved in approximately 15 g of tetrahydrofuran to prepare a solution of approximately 0.2% by weight. The weight-average molecular weight Mw and Mw / Mn were calculated from the GPC chromatogram measured under the following conditions, with polystyrene used as the standard substance. Equipment:Waters2695 Column temperature: 40℃ Detector: RI2414 (differential refractometer) Carrier eluent flow rate: 0.3 ml / min (solvent: tetrahydrofuran) Columns: TSKgel SuperHZM-M (6.0mm I.D. × 15cm), TSKgel SuperHZM-N (6.0mm I.D. × 15cm) in series (both manufactured by Tosoh).

[0057] (2) MFR (Melt Flow Rate) The epoxy group-containing vinyl copolymer (A) and thermoplastic resin compositions obtained in each example and comparative example were pre-dried in an 80°C hot air dryer for 5 hours, and the melt flow rate was measured under conditions of 220°C or 240°C and a load of 10,000 g in accordance with the provisions of ISO 1133 (2005).

[0058] (3) Weight-average particle size of rubbery polymer (R) The polybutadiene latex used in the production of the ABS graft copolymer (D) described below was diluted and dispersed in an aqueous medium, and the particle size distribution was measured using a laser scattering diffraction particle size distribution analyzer LS 13 320 (manufactured by Beckman Coulter, Inc.). From this particle size distribution, the weight-average particle size of the rubbery polymer (R) was calculated.

[0059] (4) Graft rate of ABS graft copolymer (D) Approximately 1 g (m: sample weight) of the ABS graft copolymer (D) described below was mixed with acetone and refluxed for 3 hours. This solution was then centrifuged at 8800 rpm (10000 G) for 40 minutes, and the insoluble matter was filtered off. This insoluble matter was dried under reduced pressure at 60°C for 5 hours, and its weight (n) was measured. The graft rate was calculated using the following formula. In the formula below, L represents the rubbery polymer content (weight %) of the ABS graft copolymer. Graft rate (%) = {[(n) - [(m) × L / 100]] / [(m) × L / 100]} × 100.

[0060] (5) Reduced viscosity [ηsp / c] of ABS graft copolymer (D) For the ABS graft copolymer (D) described below, 1 g of sample was mixed with 200 ml of acetone, refluxed for 3 hours, and the resulting solution was centrifuged at 8800 rpm (10000 G) for 40 minutes. The insoluble components were then filtered out. The filtrate was concentrated using a rotary evaporator, and the precipitate (acetone-soluble components) was dried under reduced pressure at 60°C for 5 hours. A 0.4 g / 100 ml methyl ethyl ketone solution (30°C) was then prepared, and its [ηsp / c] was measured using an Ubbelohde viscometer.

[0061] (6) Charpy impact strength The pellets obtained in each example and comparative example were pre-dried in a hot air dryer at 105°C for 5 hours. Using a Sumitomo Heavy Industries, Ltd. SE50 electric injection molding machine, multipurpose test specimens of type A (total length 150 mm, test section width 10 mm, thickness 4 mm) as specified in ISO 3167 (2002) were injection molded under the conditions of cylinder temperature: 260°C and mold temperature: 60°C. The impact strength of the obtained multipurpose test specimens of type A was measured in accordance with the provisions of ISO 179 (2000) under the conditions of V-notch (remaining width 8.0 mm), 23°C, and 50%RH. The Charpy impact strength (kJ / m) was measured for each of the 10 test specimens. 2 The number of ) was measured, and the average value was calculated.

[0062] (7) Formability The pellets obtained in each example and comparative example were pre-dried in a hot air dryer at 105°C for 5 hours. Using a Nissei Plastics injection molding machine "PS60", box-shaped products (30 mm wide x 30 mm deep x 30 mm high, 1.5 mm thick) with the openings shown in Figures 1 and 2 were molded from the side pin gate under molding conditions of cylinder temperature 260°C, mold temperature 80°C, and cooling time 10 seconds. Products with poor fluidity during molding that could not be filled, or test pieces that deformed when the molded product was ejected after filling, or products that buckled significantly at the ejection point were marked with "×" in the table as having poor moldability. Products that did not deform when the molded product was ejected after filling were marked with "○".

[0063] (8) Retention stability Using a melt indexer (manufactured by Toyo Seiki Co., Ltd.), pellets pre-dried at 130°C for 3 hours were used, and measurements were performed under ISO 1133 conditions of a test temperature of 250°C and a load of 2160g. During this process, the MFR at 5 minutes of residence and 20 minutes of residence were measured, and the residence stability was evaluated as follows. Change in MFR during dwell time (g / 10min) = MFR at 20 minutes of dwell time - MFR at 5 minutes of dwell time If the above calculation result is 0 or greater, it can be determined that the retention stability is good.

[0064] (9) Release force Using the pellets obtained in each example and comparative example, the release force was measured using a mold that produced the molded product shape shown in Figure 3. The molding conditions were a cylinder temperature of 260°C, a mold temperature of 80°C, and a Sumitomo Heavy Industries injection molding machine "SGE75DU" was used. For the release force measurement, a Technoplus "Load Cell 1C-1B" was inserted into the mold, a Toyo Baldwin "MD-1031" strain amplifier was used, and a Hioki E.E. CORPORATION "Memory HiCorder 8840" recording device was used to measure the release force when the bottom surface of the molded product shown in Figure 1 was ejected with four φ10 ejector pins. A release force of 500 MPa or less was considered to indicate good release properties. A pressure of 450 MPa or less is preferable.

[0065] (10) Bar flow length Using a Nissei Plastics injection molding machine "PS40," the pellets obtained in each example and comparative example were injected into strips 1 mm thick and 10 mm wide for 8 seconds, and the length (bar flow length) of the resulting strip-shaped molded product was measured. The injection conditions were a cylinder temperature of 260°C, a mold temperature of 80°C, and an injection pressure of 63 MPa. A flow length of 100 mm or more was considered to indicate good fluidity.

[0066] [Manufacturing of epoxy group-containing vinyl copolymer (A)] The method for producing the epoxy group-containing vinyl copolymer (A) used in the examples and comparative examples is as follows.

[0067] <Preparation of suspension stabilizers> 80 parts by weight of acrylamide, 20 parts by weight of methyl methacrylate, 0.3 parts by weight of potassium persulfate, and 1800 parts by weight of deionized water were charged into a reactor. The gas phase in the reactor was replaced with nitrogen gas, and the reactor was kept at 70°C under stirring. The reaction was continued until the monomers were completely converted into polymers, yielding an aqueous solution of acrylamide-methyl methacrylate copolymer. To the obtained aqueous solution, 20 parts by weight of sodium hydroxide and 2000 parts by weight of deionized water were added, and the mixture was stirred at 70°C for 2 hours. After cooling to room temperature, an aqueous solution of methyl methacrylate-acrylamide copolymer, which serves as a medium for suspension polymerization, was obtained.

[0068] <Manufacturing of epoxy group-containing vinyl copolymer (A-1)> A stainless steel autoclave with a capacity of 20 L and equipped with baffles and a Faudra-type stirring blade was placed in a solution of 0.05 parts by weight of the aqueous solution of the methyl methacrylate-acrylamide copolymer dissolved in 150 parts by weight of deionized water and stirred at 400 rpm, while purging the system with nitrogen gas. Next, a monomer mixture of 24 parts by weight of acrylonitrile, 75 parts by weight of styrene, 1 part by weight of glycidyl methacrylate, 0.32 parts by weight of 2,2'-azobisisobutyronitrile, 0.09 parts by weight of t-dodecyl mercaptan, and 0.10 parts by weight of n-octyl mercaptan was initially added over 30 minutes while stirring the reaction system, and the copolymerization reaction was started by raising the temperature to 70°C, which was then raised to 100°C over 180 minutes. After reaching 100°C, the temperature was maintained at 100°C for 30 minutes, then cooled, and the polymer was separated, washed, and dried to obtain epoxy group-containing vinyl copolymer (A-1). Here, in terms of the cumulative elution weight obtained by GPC / FT-IR, the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of less than 30% when cumulatively calculated from the low molecular weight side of the copolymer (I), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 30% or more but less than 70% when cumulatively calculated from the low molecular weight side of the copolymer (II), and the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 70% or more when cumulatively calculated from the low molecular weight side of the copolymer (III) were (I) = 0.94%, (II) = 1.05%, and (III) = 0.93%, respectively. Furthermore, the molecular weights M1 at which the concentration of the epoxy group-containing vinyl monomer unit reaches its peak value, M2 at which the cumulative value calculated from the lowest molecular weight side reaches 30% by mass, and M3 at which the cumulative value calculated from the lowest molecular weight side reaches 70% by mass were M1=134,400, M2=75,500, and M3=238,900, respectively.

[0069] <Production of epoxy group-containing vinyl copolymers (A-2 to A-8)> Epoxy group-containing vinyl copolymers A-2 to A-8 were obtained by modifying the formulation as shown in Table 1, according to the manufacturing method of A-1.

[0070] <Manufacturing of epoxy group-containing vinyl copolymer (A-9)> Copolymerization and mixing of resin components were carried out as follows using a continuous bulk polymerization apparatus consisting of a 2 m³ fully mixed polymerization tank with a monomer vapor evaporation reflux condenser and double helical ribbon blades, and a twin-screw extruder type demonomerizer. First, a monomer mixture consisting of 24 parts by weight of acrylonitrile, 75 parts by weight of styrene, 1 part by weight of glycidyl methacrylate, 0.015 parts of 1,1-di(t-butylperoxy)cyclohexane, and 0.16 parts by weight of n-octyl mercaptan was continuously supplied to the polymerization tank at 150 kg / hour, and continuous bulk polymerization was carried out while maintaining a polymerization temperature of 130°C and a tank pressure of 0.08 MPa. The polymerization rate of the polymerization reaction mixture at the end of the polymerization tank was controlled to be between 74 and 76%. The obtained polymerization reaction product was extruded in strand form using a twin-screw extruder type demonomerizer, and the unreacted monomers were recovered by vacuum distillation through the vent to achieve an apparent polymerization rate of 99% or more. The product was then pelletized by a cutter to obtain an epoxy group-containing vinyl copolymer (A-9).

[0071] [Table 1]

[0072] The following thermoplastic polyester resins (C) and ABS graft resins (D) were used.

[0073] <Thermoplastic polyester resin (C)> Polybutylene terephthalate (PBT) resin "PBT1100S" manufactured by Toray Industries, Inc. <ABS graft resin (D)> In a nitrogen-purged reactor, 120 parts by weight of pure water, 0.5 parts by weight of glucose, 0.5 parts by weight of sodium pyrophosphate, 0.005 parts by weight of ferrous sulfate, and 60 parts by weight (solid content) of polybutadiene latex (weight-average particle size 0.3 μm, gel content 85%) were charged, and the temperature inside the reactor was raised to 65°C while stirring. Polymerization was started when the internal temperature reached 65°C, and a mixture consisting of 30 parts by weight of styrene, 10 parts by weight of acrylonitrile, and 0.3 parts by weight of t-dodecyl mercaptan was continuously added dropwise over 5 hours. Simultaneously, an aqueous solution consisting of 0.25 parts by weight of cumene hydroperoxide, 2.5 parts by weight of potassium oleate, and 25 parts by weight of pure water was continuously added dropwise over 7 hours to complete the reaction. The resulting styrene copolymer latex was solidified in a dilute sulfuric acid aqueous solution at 90°C, neutralized with a sodium hydroxide aqueous solution, washed, filtered, and dried to obtain ABS graft copolymer (D). The grafting rate of this ABS graft copolymer (D) was 35%, and the reduced viscosity ηsp / c of ​​the acetone-soluble component was 0.35 dl / g.

[0074] Thermoplastic polyester resin (C), ABS graft resin (D), and epoxy group-containing vinyl copolymers (A-1 to A-9) were mixed in the proportions shown in Table 2, and the mixture was melt-kneaded using a 30 mm twin-screw extruder with a vent at a cylinder temperature of 260°C to produce pellet-shaped thermoplastic resin compositions. The MFR, Charpy impact strength, and moldability of the obtained thermoplastic resin compositions were evaluated and the results are shown in Table 2.

[0075] [Table 2]

[0076] As is clear from Table 2, Examples 1 to 4, in which the epoxy group-containing vinyl copolymer (A) of the present invention was blended with thermoplastic resin (C) and ABS graft resin (D), showed improved moldability while maintaining MFR and Charpy impact strength compared to Comparative Examples 1 to 5, which were blended with epoxy group-containing vinyl copolymers that did not satisfy the requirements of the present invention.

[0077] The following were used as reinforcing fibers (E):

[0078] <Reinforced Fiber (E)> Nippon Electric Glass Co., Ltd. "T-120H" (chopped strand, 3mm length) (Average fiber diameter: 10.5 μm)

[0079] A thermoplastic resin composition was produced by mixing a thermoplastic polyester resin (C), reinforcing fibers (E), and an epoxy group-containing vinyl copolymer (A) in the proportions shown in Table 3, and melt-kneading the mixture at a cylinder temperature of 260°C using a 30 mm twin-screw extruder with a vent. The results of evaluating the retention stability, Charpy impact strength, release force, and bar flow length of the obtained thermoplastic resin composition are shown in Table 3.

[0080] [Table 3]

[0081] As is clear from Table 3, Examples 5 and 6, in which the epoxy group-containing vinyl copolymer (A) of the present invention was blended with thermoplastic resin (C) and reinforcing fiber (E), showed improved release properties and fluidity while maintaining retention stability and Charpy impact strength compared to Comparative Examples 6 to 9, which were blended with epoxy group-containing vinyl copolymers that did not satisfy the requirements of the present invention. [Explanation of symbols]

[0082] a: Spool / Runner b: Box-shaped product for moldability evaluation

Claims

1. A copolymer (A) obtained by polymerizing a vinyl monomer mixture (a) containing at least 60 to 79.9 parts by weight of an aromatic vinyl monomer (a1), 20 to 39.9 parts by weight of a vinyl cyanide monomer (a2), and 0.1 to 3 parts by weight of an epoxy group-containing vinyl monomer (a3) ​​(where the total of (a1), (a2), and (a3) ​​is 100 parts by weight), characterized in that the weight-average molecular weight Mw on a polystyrene basis determined by GPC is 100,000 to 300,000, and the ratio Mw / Mn of weight-average molecular weight Mw to number-average molecular weight Mn is 2.5 to 3.

5.

2. The epoxy group-containing vinyl copolymer according to claim 1, characterized in that, in the cumulative elution weight obtained by GPC / FT-IR measurement of the epoxy group-containing vinyl copolymer (A), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of less than 30% when cumulatively accumulated from the low molecular weight side of the copolymer is (I), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 30% or more but less than 70% when cumulatively accumulated from the low molecular weight side of the copolymer is (II), and the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 70% or more when cumulatively accumulated from the low molecular weight side of the copolymer is (III), the composition distribution of the epoxy group-containing vinyl monomer units is (I) < (II) and (III) < (II).

3. The epoxy group-containing vinyl copolymer according to claim 1 or 2, wherein the melt flow rate at 220°C and a load of 10,000 g is 15 to 32 g / 10 min.

4. A method for producing an epoxy group-containing vinyl copolymer (A), characterized in that a copolymer is obtained by polymerizing a vinyl monomer mixture (a) comprising at least 60 to 79.9 parts by weight of an aromatic vinyl monomer (a1), 20 to 39.9 parts by weight of a vinyl cyanide monomer (a2), and 0.1 to 5 parts by weight of an epoxy group-containing vinyl monomer (a3) ​​(where the total of (a1), (a2), and (a3) ​​is 100 parts by weight), the weight-average molecular weight Mw on a polystyrene basis determined by GPC is 100,000 to 300,000, and the ratio of weight-average molecular weight Mw to number-average molecular weight Mn Mw / Mn is 2.5 to 3.5, A method for producing an epoxy group-containing vinyl copolymer, characterized by suspend polymerization of the vinyl monomer mixture (a) using two or more mercaptan-based chain transfer agents.

5. The method for producing an epoxy group-containing vinyl copolymer according to Claim 4, characterized in that, in the cumulative elution weight obtained by GPC / FT-IR measurement of the epoxy group-containing vinyl copolymer (A), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of less than 30% when cumulatively accumulated from the low molecular weight side of the copolymer is (I), the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 30% or more but less than 70% when cumulatively accumulated from the low molecular weight side of the copolymer is (II), and the average concentration of the epoxy group-containing vinyl monomer units at a cumulative value of 70% or more when cumulatively accumulated from the low molecular weight side of the copolymer is (III), the composition distribution of the epoxy group-containing vinyl monomer units is (I) < (II) and (III) < (II).

6. The method for producing an epoxy group-containing vinyl copolymer according to claim 4 or 5, characterized in that at least one of the mercaptan-based chain transfer agents is n-octyl mercaptan.

7. A thermoplastic resin composition comprising an epoxy group-containing vinyl copolymer (A) according to any one of claims 1 to 3 and a thermoplastic resin (B).

8. The thermoplastic resin composition according to claim 7, wherein the thermoplastic resin (B) comprises a thermoplastic polyester resin (C).

9. The thermoplastic resin composition according to claim 7 or 8, comprising 0.1 to 50 parts by weight of an epoxy group-containing vinyl copolymer (A) per 100 parts by weight of a thermoplastic resin (B).

10. A molded article comprising the thermoplastic resin composition according to any one of claims 7 to 9.

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