Thermoplastic resin modifier and method for producing modified thermoplastic resin using the same

Abstract

To provide a thermoplastic resin modifier capable of obtaining a recycled thermoplastic resin having sufficient resin strength, no defective appearance and no bleed-out of a modifier component in recycling of a thermoplastic resin, and to provide a recycled thermoplastic resin using the same.SOLUTION: A thermoplastic resin modifier comprising a copolymer (A) containing, as essential constituent monomers, a (meth) acrylate having a glycidyl group, a vinyl group-substituted aromatic compound, and an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin modifier and a method for producing a modified thermoplastic resin using the same. [Background technology]

[0002] Thermoplastic resins such as polyester resins are used as molding materials for plastic products such as containers, packaging films, household goods, office equipment, electrical and electronic components, and automotive parts. Many used plastic products have been disposed of by incineration or landfilling, but as the number of discarded plastic products increases, disposal by incineration or landfilling has become difficult, and so separate collection and recycling of such products as recycled thermoplastic resins has been considered.

[0003] When recycling thermoplastic resins from separated and collected waste plastic products, heat and shear forces are applied due to heating, melting, kneading, etc., which causes the polymer chains of the thermoplastic resin to be broken, reducing the degree of polymerization and resulting in poor physical properties of the recycled resin. To address this problem, Patent Document 1 proposes using a polyester resin modifier containing a copolymer of styrene, glycidyl methacrylate, and methyl methacrylate, a plastic molding lubricant, and an amorphous polyester resin in the recycling of polyester resin.

[0004] However, the method described in Patent Document 1 requires the use of an amorphous polyester resin with a different composition from the polyester resin to be recycled, and there are problems such as the modified polyester resin obtained using the modifier having a poor appearance (cloudy white appearance) and the modifier components bleeding out. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-124451 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a thermoplastic resin modifier that can be used to recycle thermoplastic resins such as polyester resins, which have sufficient resin strength, no poor appearance, and no bleed-out of modifier components. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. That is, the present invention is a method for producing a modified thermoplastic resin, which includes a step of heating and mixing a thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group, and the thermoplastic resin modifier, the thermoplastic resin modifier including a copolymer (A) having, as essential constituent monomers, a (meth)acrylate having a glycidyl group, a vinyl group-substituted aromatic compound, and an alkyl (meth)acrylate having 1 to 18 carbon atoms in the alkyl group. [Effects of the Invention]

[0008] The thermoplastic resin modifier of the present invention has the effect of producing a thermoplastic resin having sufficient resin strength, no appearance defects, and no bleed-out of the modifier component in a thermoplastic resin such as a polyester resin. DETAILED DESCRIPTION OF THE INVENTION

[0009] The thermoplastic resin modifier of the first invention of this application contains a copolymer (A) whose essential constituent monomers are a (meth)acrylate having a glycidyl group, a vinyl-substituted aromatic compound, and an alkyl (meth)acrylate having an alkyl group having 1 to 18 carbon atoms.

[0010] Examples of the (meth)acrylate having a glycidyl group include glycidyl (meth)acrylate and 4-hydroxybutyl acrylate glycidyl ether, and from the viewpoint of the resin strength of the thermoplastic resin, glycidyl methacrylate is preferred.

[0011] Examples of vinyl-substituted aromatic compounds include styrene, hydrocarbyl (alkyl, cycloalkyl, aralkyl, and / or alkenyl)-substituted styrenes having 1 to 7 carbon atoms in the substituent (e.g., α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, and benzylstyrene), and hydroxyl group-containing styrene compounds having 8 to 15 carbon atoms (e.g., hydroxystyrene). These may be used alone or in combination of two or more. As the vinyl-substituted aromatic compound, styrene is preferred from the viewpoint of resin strength of the thermoplastic resin.

[0012] An alkyl(meth)acrylate in which the alkyl group has 1 to 18 carbon atoms means an acrylic acid alkyl ester in which the alkyl group has 1 to 18 carbon atoms and / or a methacrylic acid alkyl ester in which the alkyl group has 1 to 18 carbon atoms. The alkyl group may be a straight-chain alkyl group or a branched alkyl group. Examples of alkyl (meth)acrylates in which the alkyl group is straight-chain and the alkyl group has 1 to 18 carbon atoms include methyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, n-pentadecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-heptadecyl (meth)acrylate, and n-octadecyl (meth)acrylate. Examples of alkyl (meth)acrylates in which the alkyl group is a branched alkyl group and the alkyl group has 1 to 18 carbon atoms include isopropyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, isopentyl (meth)acrylate, sec-pentyl (meth)acrylate, 3-pentyl (meth)acrylate, tert-pentyl (meth)acrylate, 2-methylpentyl (meth)acrylate, 2-methylhexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethyloctyl (meth)acrylate, 2-ethyldecyl (meth)acrylate, and 2-methyltridecyl (meth)acrylate. acrylate, 2-methyltetradecyl(meth)acrylate, 2-methylpentadecyl(meth)acrylate, 2-methylhexadecyl(meth)acrylate, 2-methylheptadecyl(meth)acrylate, 2-methyloctadecyl(meth)acrylate, 2-methylnonadecyl(meth)acrylate, 2-methylicosyl(meth)acrylate, 3-methyltetradecyl(meth)acrylate, 4-methyltetradecyl(meth)acrylate, 2-ethyltetradecyl(meth)acrylate, 2-ethylhexadecyl(meth)acrylate, 2-ethyloctadecyl(meth)acrylate, 2-hexyldecyl(meth)acrylate, and 2-hexyldodecyl(meth)acrylate.

[0013] The copolymer (A) may contain, as a constituent monomer, a monomer other than the (meth)acrylate having a glycidyl group, the vinyl-substituted aromatic compound, and the alkyl (meth)acrylate having an alkyl group of 1 to 18 carbon atoms (hereinafter referred to as the other monomer). Examples of other monomers include nitrogen atom-containing monomers and hydroxyl group-containing monomers.

[0014] Examples of the nitrogen atom-containing monomer include an acrylamide monomer (a511) and an amino group-containing monomer (a512). Examples of the acrylamide monomer (a511) include those having one (meth)acryloyl group, such as (meth)acrylamide and amino group-containing (meth)acrylamides having 5 to 10 carbon atoms {e.g., N-aminoalkyl (having 1 to 6 carbon atoms) (meth)acrylamides (e.g., N-methyl(meth)acrylamide, N-aminoethyl(meth)acrylamide, etc.)). The amino group-containing monomer (a512) includes amino group-containing (meth)acrylates other than (a511) that have one (meth)acryloyl group and have 5 to 15 carbon atoms. Examples include aminoalkyl (C1 to 6) (meth)acrylates (e.g., aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, etc.), alkyl (C1 to 6) aminoalkyl (C1 to 6) (meth)acrylates (e.g., t-butylaminoethyl methacrylate, etc.), and dialkyl (alkyl C1 to 4) aminoalkyl (C1 to 4) (meth)acrylates (e.g., dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, etc.).

[0015] Examples of hydroxyl group-containing monomers include those having one (meth)acryloyl group, such as hydroxyalkyl (carbon number 1 to 6) (meth)acrylates (e.g., hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, etc.), and hydroxyl group-containing monomers having a poly(n=2 to 30) oxyalkylene (oxyalkylene group carbon number 2 to 4) chain (e.g., polyoxyethylene mono(meth)acrylate, etc.).

[0016] In copolymer (A), the weight proportion of the structural units based on a (meth)acrylate having a glycidyl group is preferably 1 to 70% by weight, more preferably 35 to 60% by weight, based on the total weight of the structural monomers of copolymer (A), from the viewpoint of resin strength of the thermoplastic resin.

[0017] In copolymer (A), the weight proportion of the constituent units based on the vinyl group-substituted aromatic compound is preferably 20 to 70% by weight, more preferably 30 to 60% by weight, based on the total weight of the constituent monomers of copolymer (A), from the viewpoint of the resin strength of the recycled thermoplastic resin.

[0018] In the copolymer (A), the weight proportion of the structural units based on alkyl (meth)acrylate in which the alkyl group has 1 to 18 carbon atoms is preferably 1 to 30% by weight, more preferably 5 to 20% by weight, based on the total weight of the structural monomers of the copolymer (A).

[0019] In copolymer (A), the weight proportion of other monomers in all constituent monomers is preferably 10% by weight or less, more preferably 5% by weight or less, based on the weight of copolymer (A), from the viewpoint of resin strength of the thermoplastic resin.

[0020] The copolymer (A) can be obtained by polymerizing a monomer composition containing a (meth)acrylate having a glycidyl group, a vinyl-substituted aromatic compound, and an alkyl (meth)acrylate having an alkyl group with a carbon number of 1 to 18 by a known method, and can be obtained by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. Among these methods, solution polymerization can be preferably used. As a method for obtaining the copolymer (A) by solution polymerization, a method in which a monomer composition and a polymerization initiator are dropped into a solvent to polymerize can be preferably used. The polymerization temperature in the solution polymerization is preferably 70 to 230°C, more preferably 80 to 180°C, from the viewpoint of protecting the glycidyl group.

[0021] The weight average molecular weight of the copolymer (A) is preferably from 2,000 to 10,000, more preferably from 3,000 to 5,000, from the viewpoint of resin strength of the thermoplastic resin.

[0022] The weight average molecular weight of the copolymer (A) is measured by dissolving the copolymer (A) in tetrahydrofuran (THF) as a sample solution and using gel permeation chromatography (GPC) under the following conditions. Equipment: Tosoh Corporation HLC-8120 Column: TSK GEL GMH6 (2 columns) (Tosoh Corporation) Measurement temperature: 40℃ Sample solution: 0.25 wt% THF solution Solution injection volume: 100μL Detector: Refractive index detector Reference material: Tosoh standard polystyrene [TSKstandard POLYSTYRENE] 12 points (molecular weight: 500,1050,2800,5970,9100,18100,37900,96400,190000,355000,1090000,2890000)

[0023] The glycidyl group concentration (mol / kg) in the copolymer (A) is preferably 0.1 to 5.0 mol / kg, more preferably 2.8 to 4.2 mol / kg, based on the weight of the copolymer (A), from the viewpoint of resin strength of the thermoplastic resin. The epoxy group concentration can be calculated from the epoxy equivalent (g / eq) measured by a method in accordance with JIS K 7236 using the following formula: Epoxy group concentration (mol / kg) = 1000 / epoxy equivalent

[0024] The solubility parameter (hereinafter abbreviated as SP value) of the copolymer (A) is 8.0 to 11.0 (cal / cm 3 ) 1 / 2 is preferable, and more preferably 9.0 to 10.0 (cal / cm 3 ) 1 / 2 The SP value in the present invention can be calculated by the method by Fedors [Polym. Eng. Sci. 14(2)152, (1974)].

[0025] The acid value of the copolymer (A) is preferably 10 (mgKOH / g) or less, based on the weight of the copolymer (A), as measured in accordance with JIS K0070, from the viewpoint of preventing deterioration of the thermoplastic resin due to transesterification.

[0026] The evaporation residue of the copolymer (A) is preferably 99.5% by weight or more, more preferably 99.9% by weight or more, in order to prevent bubbles from forming in the molded product.

[0027] The glass transition temperature of the copolymer (A) is preferably 30°C to 100°C, more preferably 40°C to 70°C, from the viewpoint of maintaining the particle size of the copolymer (A) and uniformly melting it into the thermoplastic resin.

[0028] From the viewpoints of suppressing bleed-out from the thermoplastic resin and compatibility, the copolymer (A) preferably has a melt viscosity at 150°C measured using a single cylindrical rotational viscometer specified in JIS Z8803, Method for measuring viscosity of liquids, of 300 mPa·s or more and 9000 mPa·s or less, and more preferably 1000 mPa·s or more and 7000 mPa·s or less. The melt viscosity at 150°C using a single cylindrical rotational viscometer is measured by heating and melting the copolymer (A) using an aluminum block heater or the like set at 150°C and using a B-type viscometer, such as a Viscoblock VTB-250 manufactured by Toki Sangyo Co., Ltd.

[0029] The thermoplastic resin modifier of the present invention may contain known resin additives (colorants, antioxidants, ultraviolet absorbers, granulating agents, antistatic agents, etc.) in addition to the copolymer (A). The weight proportion of the copolymer (A) contained in the thermoplastic resin modifier of the present invention is preferably 90% by weight or more, more preferably 95% by weight or more, based on the weight of the thermoplastic resin modifier.

[0030] Although there are no limitations on the shape of the thermoplastic resin modifier of the present invention, from the viewpoint of dispersibility in the thermoplastic resin, the weight average particle diameter is preferably 10 mm or less, more preferably 4 mm or less. The weight average particle diameter can be measured by a method conforming to JIS Z8815, General Rules for Sieving Test Methods, and a thermoplastic resin modifier with a preferred particle diameter can be obtained by pulverizing the copolymer (A) using a known pulverizer.

[0031] The thermoplastic resin to be modified by the thermoplastic resin modifier of the present invention is preferably a thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group. The functional group possessed by the thermoplastic resin may be a functional group at the end of the molecular chain of the polymer compound constituting the resin, or a functional group located in the middle of the molecular chain. However, it is preferable that the functional group at the end of the molecular chain is at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group.

[0032] Among the preferred thermoplastic resins, examples of thermoplastic resins having only hydroxyl groups at the ends of the polymer chain include polyether resins.

[0033] Among the preferred thermoplastic resins, examples of thermoplastic resins having an amino group and / or a carboxyl group at the end of the polymer chain include polyamide resins, ring-opening polymers of polycaprolactam, and condensation polymers of polycarboxylic acid components and polyamine components.

[0034] Among the preferred thermoplastic resins, examples of thermoplastic resins having a hydroxyl group and / or a carboxyl group at the end of the polymer chain include polyester resins (such as ring-opening polymers of polycaprolactone and condensation polymers of polycarboxylic acid components and polyol components) and polycarbonate resins.

[0035] As the thermoplastic resin to be modified by the thermoplastic resin modifier of the present invention, polyester resins and polycarbonate resins are preferred from the viewpoint of the efficiency of modification by the thermoplastic resin modifier.

[0036] As the polyester resin to be modified by the thermoplastic resin modifier of the present invention, both crystalline polyester resins (polyethylene terephthalate, polybutylene terephthalate, etc.) and amorphous polyester resins can be preferably used.

[0037] The weight average molecular weight of the thermoplastic resin modified by the thermoplastic resin modifier of the present invention is preferably 10,000 to 200,000, more preferably 10,000 to 100,000, from the viewpoint of the efficiency of modification by the thermoplastic resin modifier. The weight average molecular weight of the thermoplastic resin is measured in the same manner as the weight average molecular weight of the copolymer (A).

[0038] When the thermoplastic resin modifier of the present invention is melt-mixed with the thermoplastic resin, the glycidyl group of the copolymer (A) reacts with the functional group of the thermoplastic resin, and the molecular weight of the thermoplastic resin is increased. This allows a modified thermoplastic resin to be obtained in which the physical properties of the thermoplastic resin (melt viscosity, glass transition temperature, crystallization temperature, strength in the solid state, etc.) are modified.

[0039] As the thermoplastic resin to be modified by the thermoplastic resin modifier of the present invention, recycled thermoplastic resins obtained by material recycling from used plastic products can also be preferably used. In the recycling process, the heat and shear force applied to recycled thermoplastic resins cuts the polymer chains of the thermoplastic resin, reducing its degree of polymerization, but this creates hydroxyl and / or carboxyl groups at the terminals. The thermoplastic resin modifier of the present invention can increase the molecular weight that has been reduced by reacting the glycidyl group with the hydroxyl group and / or carboxyl group generated at the molecular end by cleavage. Therefore, by modifying recycled thermoplastic resin, it is possible to obtain recycled thermoplastic resin that can also be used as a molding material for plastic products. The thermoplastic resin modifier of the present invention can be preferably used for producing recycled thermoplastic resins.

[0040] The second invention of the present application relates to a method for producing a modified thermoplastic resin, which includes a step of heating and mixing a thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group with the thermoplastic resin modifier. This is a method for producing a modified thermoplastic resin.

[0041] The thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group used in the method for producing a modified thermoplastic resin of the present invention is the same as the thermoplastic resin exemplified as the thermoplastic resin that can be modified by the thermoplastic resin modifier, and the preferred thermoplastic resin is also the same.

[0042] The thermoplastic resin modifier used in the method for producing a modified thermoplastic resin of the present invention is the same as the thermoplastic resin modifier described above as the first invention, and the preferred thermoplastic resin modifier is also the same.

[0043] The step of heating and mixing the thermoplastic resin and the thermoplastic resin modifier can be carried out using a known melt kneader such as a single-screw extruder or a twin-screw extruder. The thermoplastic resin and thermoplastic resin modifier to be subjected to the heating and mixing step may be in any form as long as they can be fed into the melt kneader to be used.

[0044] In the process of heating and mixing the thermoplastic resin and the thermoplastic resin modifier, the ratio of the thermoplastic resin to the thermoplastic resin modifier can be adjusted depending on the amount of functional groups in the thermoplastic resin and the glycidyl group concentration of the thermoplastic resin modifier. From the viewpoint of the resin strength of the modified thermoplastic resin, the weight proportion of the thermoplastic resin modifier is preferably 0.1 to 2 wt%, more preferably 0.1 to 1 wt%, based on the total weight of the thermoplastic resin and the thermoplastic resin modifier.

[0045] The modified thermoplastic resin may contain, in addition to the copolymer (A) and the thermoplastic resin, a known epoxy curing accelerator, such as a tertiary amine, imidazole, phosphine, or phosphonium salt.

[0046] Examples of tertiary amines include hexamethylenetetramine, triethylenediamine, 1,8-diazabicyclo(5,4,0)-undecene (DBU), 1,5-diazabicyclo(4,3,0)-nonene, and tris(dimethylaminomethyl)phenol.

[0047] Examples of imidazoles include 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0048] Examples of phosphines include triphenylphosphine, trimethoxyphenylphosphine, and tricyclohexylphosphine.

[0049] Examples of the cation moiety of the phosphonium salt include tetraalkyl (C1-7) phosphonium, alkyl (C1-7) triphenylphosphonium, tetraphenylphosphonium salt, etc. Examples of the anion moiety include halide ions (chloride, bromide, iodide), borate salts, sulfonate salts, etc.

[0050] The epoxy curing accelerator is preferably a phosphine or a phosphonium salt, more preferably a phosphonium salt, from the viewpoint of the appearance of the resin due to coloring. When an epoxy curing accelerator is used, the weight of the epoxy curing accelerator is preferably 2 to 20% by weight, more preferably 5 to 15% by weight, based on the weight of the copolymer (A).

[0051] The heating temperature in the process of heat-mixing the thermoplastic resin and the thermoplastic resin modifier may be selected according to the type of thermoplastic resin as long as it is above the melting point of the thermoplastic resin. When recycled polyethylene terephthalate is used as the thermoplastic resin, 240 to 300 ° C is preferred. When virgin polyethylene terephthalate is used as the thermoplastic resin, 280 to 300 ° C is preferred. When polybutylene terephthalate is used as the thermoplastic resin, 230 to 300 ° C is preferred. When polycarbonate is used as the thermoplastic resin, 260 to 280 ° C is preferred.

[0052] The mixing time in the step of heating and mixing the thermoplastic resin and the thermoplastic resin modifier can be adjusted depending on the amount of functional groups in the thermoplastic resin and the glycidyl group concentration of the thermoplastic resin modifier, but from the viewpoint of the resin strength of the modified thermoplastic resin, it is preferably 3 to 15 minutes, more preferably 5 to 10 minutes.

[0053] In the method for producing a modified thermoplastic resin of the present invention, a modified recycled thermoplastic resin can be obtained by using a thermoplastic resin recycled from used plastic products as the thermoplastic resin.

[0054] The present specification discloses the following:

[0055] The present disclosure (i) is a thermoplastic resin modifier containing a copolymer (A) whose essential constituent monomers are a (meth)acrylate having a glycidyl group, a vinyl-substituted aromatic compound, and an alkyl (meth)acrylate having 1 to 18 alkyl carbon atoms.

[0056] Disclosure (ii) is the thermoplastic resin modifier according to disclosure (i), wherein the thermoplastic resin is a thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group.

[0057] Disclosure (iii) is the thermoplastic resin modifier according to Disclosures (i) and (ii), in which the constituent units based on a (meth)acrylate having a glycidyl group, the constituent units based on a vinyl group-substituted aromatic compound, and the constituent units based on an alkyl (meth)acrylate having 1 to 18 alkyl carbon atoms account for 1 to 70 wt %, 20 to 70 wt %, and 1 to 30 wt %, respectively, based on the total weight of the constituent monomers.

[0058] The present disclosure (iv) is the thermoplastic resin modifier according to any one of the disclosures (i) to (iii), in which the copolymer (A) has a weight average molecular weight of 2,000 to 10,000.

[0059] The present disclosure (v) is a thermoplastic resin modifier according to any one of the disclosures (i) to (iv) for use in producing recycled thermoplastic resin.

[0060] The present disclosure (vi) is a method for producing a modified thermoplastic resin, comprising a step of heating and mixing a thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group with the thermoplastic resin modifier described in disclosures (i) to (iv). [Example]

[0061] The present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[0062] <Examples 1 to 7, Comparative Example 1> A monomer composition was prepared by mixing a (meth)acrylate having a glycidyl group, a vinyl group-substituted aromatic compound, an alkyl (meth)acrylate having an alkyl group with 1 to 18 carbon atoms, and a polymerization initiator in the weight parts shown in the composition of copolymer (A) in Table 1. A pressure-resistant reactor equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen inlet was charged with 60 parts by weight of xylene, and after the air in the reactor was replaced with nitrogen gas while stirring, the mixture was heated to reflux. Next, after heating under reflux, the vessel was sealed and heated to 160°C, and then the monomer composition was added dropwise over 3 hours with stirring, and then the polymerization reaction was carried out at the same temperature for 1 hour with continued stirring. Thereafter, the polymerization solvent, xylene, was removed by distillation under reduced pressure to obtain copolymers (A1 to 7, comparison A-1) according to Examples 1 to 7 and Comparative Example 1, and thermoplastic resin modifiers consisting of copolymers (A1 to 7, comparison A-1).

[0063] [Table 1]

[0064] The (meth)acrylate having a glycidyl group, the vinyl-substituted aromatic compound, and the alkyl (meth)acrylate having an alkyl group with 1 to 18 carbon atoms shown in Table 1 refer to the following compounds. <(Meth)acrylate having a glycidyl group> GMA: Glycidyl methacrylate <Alkyl (meth)acrylate with alkyl group having 1 to 18 carbon atoms> MMA: Methyl methacrylate IBA: Isobutyl acrylate C18MA: n-octadecyl methacrylate

[0065] <Examples 11 to 21, 22 to 32, 33 to 43, Comparative Examples 11, 22, and 33> The thermoplastic resin modifier consisting of the copolymers (A1 to 7, ratio A-1) obtained in Examples 1 to 7 and Comparative Example 1, each in the weight parts shown in Table 2, and the thermoplastic resin were melt-kneaded for 5 minutes in the sample kneading section of a kneading test device (Labo Plastomill) manufactured by Toyo Seiki Seisakusho, Ltd. to modify the thermoplastic resin and obtain a modified thermoplastic resin. The temperature of the sample kneading section was 280°C when polyethylene terephthalate (PET) was used as the thermoplastic resin, 260°C when recycled polyethylene terephthalate (R-PET) was used as the thermoplastic resin, 280°C when polycarbonate (PC) was used as the thermoplastic resin, and 260°C when polybutylene terephthalate (PBT) was used as the thermoplastic resin. The melt-kneading in the sample kneading section was carried out by first placing only the pre-dried thermoplastic resin in the sample kneading section heated to the temperatures listed in Tables 2 to 4 and melt-kneading it, then adding the thermoplastic resin modifier, and then melt-kneading it for another 5 minutes. The modified thermoplastic resins (modified polyethylene terephthalate resins) obtained in Examples 11 to 21 and Comparative Example 11 were evaluated for intrinsic viscosity (IV), tensile stress, transparency, and whether or not the modifier bleeds out using the methods described below, and the results are listed in Table 2. The modified thermoplastic resins (modified polycarbonate resins) obtained in Examples 22 to 32 and Comparative Example 22 were evaluated for melt mass-flow rate (MFR), tensile stress, transparency, and whether or not the modifier bleeds out using the following methods, and the results are shown in Table 3. The modified thermoplastic resins (modified polybutylene terephthalate resins) obtained in Examples 33 to 43 and Comparative Example 33 were evaluated for tensile stress and the presence or absence of bleed-out of the modifier by the following methods, and the results are shown in Table 4.

[0066] The thermoplastic resins listed in Tables 2 to 4 refer to the following resins. <Thermoplastic resin> PET: Polyethylene terephthalate resin manufactured by Unitika Ltd. [Product name: NES-2040] R-PET: Recycled polyethylene terephthalate resin manufactured by Pantech Co., Ltd. [Model number: PET (09D022901C)] PC: Polycarbonate resin manufactured by Teijin Limited [Product name: Panlite L-1225L] PBT: Polybutylene terephthalate resin manufactured by Toray Industries, Inc. [Product name: Toraycon M1200]

[0067] <Intrinsic viscosity (IV)> The viscosity number measured in accordance with JIS K 7367-5 is shown in Table 2 as the intrinsic viscosity. The measurement solvent was phenol / 1,2-dichlorobenzene (50 / 50). The intrinsic viscosity (IV) of the thermoplastic resin used to obtain the modified thermoplastic resin was 0.72 for PET and 0.6 for R-PET.

[0068] <Melt mass-flow rate (MFR)> The melt mass-flow rate values ​​measured using a standard die at a test temperature of 300°C and a load of 1.2 kg in accordance with the method specified in JIS K7210 Plastics - Method for determining melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics are shown in Table 3. The MFR of the PC measured for the thermoplastic resin used in Table 3 was 18.

[0069] <Tensile stress> The measurements were carried out in a room controlled at 20° C. using a tensile tester specified in JIS B7721 according to the method described in JIS K7161, Plastics - Determination of tensile properties, and the results are shown in Tables 2 to 4. The shape of the test piece was a dumbbell type 1A as specified in JIS K7161, the test speed was 10 mm / min, and the average value of five measurements was taken as the tensile stress. The tensile stress of the thermoplastic resins used to obtain the modified thermoplastic resins in Examples 11 to 43 and Comparative Examples 11, 22, and 33 was 54 MPa for PET, 49 MPa for R-PET, 61 MPa for PC, and 53 MPa for PBT.

[0070] <Transparency> A film molded to a thickness of 20 μm was visually observed, and the results were recorded in Tables 2 and 3 as follows: ○ if the opposite side was clearly visible through the test piece; △ if the opposite side was visible but was hazy white; and × if the opposite side could not be seen.

[0071] <Whether or not the modifier bleeds out> The surface of the film whose transparency had been measured was touched with bare hands to check whether or not there were any irregularities on the surface. If separation was observed visually (such as the occurrence of a separation layer or irregularities on the surface due to separation), it was determined that there was bleed-out of copolymer (A), and this was recorded as × in Tables 2 to 4. If there was no irregularity, it was determined that there was no bleed-out, and this was recorded as ○ in Tables 2 to 4.

[0072] [Table 2]

[0073] [Table 3]

[0074] [Table 4]

[0075] By heating and mixing the thermoplastic resin modifier of the present invention with thermoplastic resins such as polyester resin and polycarbonate resin, a transparent modified thermoplastic resin can be obtained that does not bleed out of the modifier components, compared to when the comparative copolymer (comparison A-1) is heated and mixed with the thermoplastic resin. [Industrial Applicability]

[0076] The thermoplastic resin modifier of the present invention can improve resin strength while maintaining a good appearance, and therefore can be suitably used as a resin modifier in material recycling of thermoplastic resins extracted from separated and collected waste plastic products as molding resins.

Claims

1. A thermoplastic resin modifier comprising a copolymer (A) having, as essential constituent monomers, a (meth)acrylate having a glycidyl group, a vinyl-substituted aromatic compound, and an alkyl (meth)acrylate having an alkyl group having 1 to 18 carbon atoms.

2. 2. The thermoplastic resin modifier according to claim 1, wherein the thermoplastic resin is a thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group.

3. The structural units based on a (meth)acrylate having a glycidyl group, the structural units based on a vinyl group-substituted aromatic compound, and the structural units based on an alkyl (meth)acrylate having 1 to 18 carbon atoms in the alkyl group are 1 to 70% by weight, 20 to 70% by weight, and 1 to 30% by weight, respectively, based on the total weight of the structural monomers. The thermoplastic resin modifier according to claim 1.

4. The thermoplastic resin modifier according to claim 1, wherein the weight average molecular weight of the copolymer (A) is 2,000 to 10,000.

5. The thermoplastic resin modifier according to any one of claims 1 to 4, which is used for producing recycled thermoplastic resins.

6. A thermoplastic resin having at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group, and the thermoplastic resin modifier according to claims 1 to 4. A method for producing a modified thermoplastic resin, comprising the steps of:

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