Polymer, resin composition and molded body

Abstract

To improve compatibility between a polyester resin and other resin.SOLUTION: A polymer has a first polymer part and a second polymer part, wherein the first polymer part is a polyester-based polymer; the second polymer part has a constitutional unit which is different from a constitutional unit constituting the first polymer part and is derived from a (meth)acrylate monomer; in molecular weight measurement by gel permeation chromatography, a value of a peak top derived from the second polymer part is 1,000 or more and 50,000 or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polymer, a resin composition, and a molded article. [Background technology]

[0002] Conventionally, attempts have been made to mix multiple resins to achieve functions or improve performance that cannot be achieved with a single resin. However, since many combinations of resin types are incompatible, the performance or function of the composite is often lower than that of a single resin. Therefore, compatibilizers are added to improve the compatibility of multiple resin types.

[0003] Patent Document 1 discloses a resin composition obtained by blending an aromatic vinyl resin, a thermoplastic resin, and a copolymer of a vinyl resin portion and a polyester resin portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-219074 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is room for improvement in the function as a compatibilizer of the copolymer described in Patent Document 1. An object of one aspect of the present invention is to provide a polymer or the like that can improve the compatibility between a polyester resin and other resins. [Means for solving the problem]

[0006] A polymer according to one embodiment of the present invention is a polymer having a first polymer portion and a second polymer portion, wherein the first polymer portion is composed of a polyester-based polymer, and the second polymer portion is a polymer different from the first polymer portion and has a structural unit derived from a (meth)acrylate monomer, and in molecular weight measurement by gel permeation chromatography using tetrahydrofuran as an eluent and polymethyl methacrylate as a standard sample, the peak top value derived from the second polymer portion is 1,000 or more and 50,000 or less. Effect of the Invention

[0007] According to one aspect of the present invention, it is possible to provide a polymer or the like that can improve the compatibility between a polyester resin and other resins. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An embodiment of the present invention will be described in detail below. In this specification, "A to B" indicating a numerical range means "A or more and B or less" unless otherwise specified. Note that the following description is one embodiment of the present invention, and the present invention is not limited to the following configuration.

[0009] A polymer according to one embodiment of the present invention is a polymer (hereinafter, sometimes referred to as "polymer A") having a first polymer portion composed of a polyester polymer and a second polymer portion composed of a polymer different from the polymer that composes the first polymer portion. By using the polymer A as a compatibilizer for two or more matrix resins including a polyester resin, it is possible to improve the compatibility between the first matrix resin and the second matrix resin. Therefore, it is possible to reduce phase separation between the first matrix resin and the second matrix resin.

[0010] [1. Polymer A] Polymer A according to one embodiment of the present invention is a polymer having a first polymer portion and a second polymer portion. The first polymer portion is composed of a polyester-based polymer. The second polymer portion is composed of a polymer different from the polymer constituting the first polymer portion. The second polymer portion has a constitutional unit derived from a (meth)acrylate monomer. In addition, in molecular weight measurement by gel permeation chromatography (GPC), polymer A has a peak top value derived from the second polymer portion of 1,000 or more and 50,000 or less.

[0011] The present inventors have newly discovered that when polymer A is used as a compatibilizer, the larger the molecular weights of the various polymers constituting polymer A, the more preferable it is. However, when the molecular weight of the second polymer portion is within a predetermined range, polymer A functions favorably as a compatibilizer.

[0012] The content of the first polymer portion is preferably 20 parts by mass or more and 70 parts by mass or less, based on 100 parts by mass of the total of the first polymer portion and the second polymer portion. The upper limit of the content is preferably 60 parts by mass or less, more preferably 50 parts by mass or less. With this configuration, the compatibility between the first matrix resin and the second matrix resin can be improved by the polymer A.

[0013] In one embodiment of the present invention, the polymer A having a first polymer portion and a second polymer portion may be a polymer in which the first polymer portion and the second polymer portion are covalently bonded to each other. In another embodiment of the present invention, the polymer A also includes a complex in which the first polymer portion and the second polymer portion are not covalently bonded to each other and the first polymer portion is encapsulated or enclosed by the second polymer portion.

[0014] An example of the polymer A in which the first polymer portion and the second polymer portion are covalently bonded is a block copolymer having a first polymer portion and a second polymer portion. In addition, an example of the polymer in which the first polymer portion is encapsulated or enveloped by the second polymer portion is a polymer having a core-shell structure composed of a core portion and a shell portion. The core-shell structure is a structure in which a portion called the core is encapsulated in a portion called the shell. The polymer having the core-shell structure may be one in which the core portion contains one of the first polymer portion and the second polymer portion, and the shell portion contains the other of the first polymer portion and the second polymer portion.

[0015] Among them, the polymer A is preferably a polymer having a core-shell structure, in which the first polymer portion constitutes the shell portion of the core-shell structure. That is, the polymer A is preferably a polymer having a core-shell structure, in which the first polymer portion constituted by a polyester polymer constitutes the shell portion, and the second polymer portion constituted by a polymer different from the first polymer portion constitutes the core portion. Below, a preferred embodiment of the polymer A having the core-shell structure will be described in detail as a representative example.

[0016] <1-1. First polymer portion> As described above, the first polymer portion is composed of a polyester-based polymer. In one embodiment of the present invention, the polyester-based polymer means a polymer composed of a structural unit containing an ester bond as a repeating unit, and the polyester may be synthesized by a polycondensation reaction between a dicarboxylic acid component and a diol component. By the first polymer portion being composed of a polyester-based polymer, the affinity with the first matrix resin, which is a polyester resin, is improved, and as a result, the compatibility between the first matrix resin and the second matrix resin is improved.

[0017] The dicarboxylic acid is not particularly limited, and examples thereof include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Examples of such aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, 2,5-norbonanedicarboxylic acid, 1,4-naphthalic acid, 1,5-naphthalic acid, 4,4-oxybenzoic acid, fumaric acid, maleic anhydride, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, tetrahydrophthalic anhydride, tetrahydroterephthalic acid, 5-sodium sulfoisophthalic acid, 5-lithium sulfoisophthalic acid, trimellitic anhydride, and pimellitic anhydride.

[0018] The diol component is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, triethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, an ethylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A, an ethylene oxide and propylene oxide adduct of bisphenyl A, an ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, polytetramethylene glycol, polyethylene glycol, polypropylene glycol and modified products thereof, and sodium sulfobutanediol.

[0019] Two or more kinds of dicarboxylic acid components may be used, and similarly, two or more kinds of diol components may be used.

[0020] The first polymer portion may be composed of a plurality of polymers each having a plurality of different structural units. In this case, the structural units may be any of those exemplified as the structural units of the first polymer.

[0021] The molecular weight measurement of polymer A by GPC can be performed by dissolving polymer A in tetrahydrofuran at a concentration of 0.2% by weight as a measurement sample, estimating the molecular weight using tetrahydrofuran as an eluent and a polymethyl methacrylate standard sample. The chromatogram obtained by such a method includes a peak derived from the first polymer portion and a peak derived from the second polymer portion. The peak derived from the first polymer portion can be identified from the molecular weight of the first polymer portion calculated from the ratio of the integrated intensity derived from the terminal structure of the first polymer portion obtained by NMR measurement to the integrated intensity derived from the polymer main chain of the first polymer portion.

[0022] The glass transition temperature of the first polymer portion is not particularly limited, but in order to ensure powder recoverability, it is preferably 40° C. or higher, more preferably 45° C. or higher, and even more preferably 50° C. or higher. On the other hand, in order to avoid pulverization of the powder, the glass transition temperature is preferably 150° C. or lower, more preferably 130° C. or lower, and even more preferably 100° C. or lower.

[0023] <1-2. Second polymer portion> The second polymer portion is composed of a polymer different from the first polymer portion. The second polymer portion has a constitutional unit derived from a (meth)acrylate monomer. The second polymer portion has a constitutional unit derived from a (meth)acrylate monomer, and thus the tensile elongation of a molded article of the resin composition containing polymer A is improved. The second polymer portion preferably has a constitutional unit other than the constitutional unit derived from the (meth)acrylate monomer, and such a constitutional unit is preferably a component having excellent affinity with the second matrix resin. Specifically, it is preferable that at least a part of the constitutional units of the second polymer portion and at least a part of the constitutional units constituting the second matrix resin are the same.

[0024] Regarding the (meth)acrylate monomer-derived constituent unit constituting the second polymer portion, examples of the (meth)acrylate monomer include methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, propyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, propyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, phenyl acrylate, phenyl methacrylate, hydroxyethyl acrylate, 4-hydroxybutyl acrylate, benzyl acrylate, benzyl methacrylate, polyalkylene glycol monoacrylate, and polyalkylene glycol monomethacrylate. Among these, methyl methacrylate, butyl acrylate, glycidyl methacrylate, and polyalkylene glycol monomethacrylate are preferred from the viewpoint of tensile elongation of the molded article.

[0025] The content of the constitutional unit derived from the (meth)acrylate monomer relative to 100 parts by mass of the second polymer portion is not particularly limited, but in order to further improve the compatibility between the first matrix resin and the second matrix resin and to further improve the tensile elongation of the molded article, it is preferably 20 parts by mass or more, and on the other hand, 80 parts by mass or less, and more preferably 25 parts by mass or more and 60 parts by mass or less.

[0026] The structural units constituting the second polymer portion other than the structural units derived from the (meth)acrylate monomer are preferably set according to the structure of the second matrix resin to be used. Examples of such structural units include structural units derived from aromatic vinyl monomers. When the structural units constituting the second polymer portion contain structural units derived from aromatic vinyl monomers, for example, when a polystyrene-containing resin is used as the second matrix resin, the affinity between the second polymer portion and the polystyrene-containing resin is good. As a result, it can be expected that the compatibility between the first matrix resin and the second matrix resin will be better.

[0027] Among them, the constitutional unit constituting the second polymer portion is more preferably a constitutional unit derived from an aromatic vinyl monomer having a six-membered monocyclic structure, and more preferably a constitutional unit derived from styrene which may have a substituent. Examples of the constitutional unit derived from styrene which may have a substituent include a constitutional unit derived from styrene or a constitutional unit derived from α-methylstyrene, and among them, a constitutional unit derived from styrene is particularly preferred.

[0028] There is no particular limitation on the content of the aromatic vinyl monomer-derived structural unit per 100 parts by mass of the second polymer portion. However, in order to further improve the compatibility between the first matrix resin and the second matrix resin, the content is preferably 30 parts by mass or more, more preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and more preferably 70 parts by mass or more; on the other hand, the content is preferably 95 parts by mass or less and less than 100 parts by mass.

[0029] The second polymer portion may further have other structural units. There is no particular limitation on the content of the other structural units relative to 100 parts by mass of the second polymer portion, but in order to further improve the compatibility between the first matrix resin and the second matrix resin, the content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and more preferably 20 parts by mass or less, while it is 0 parts by mass or more.

[0030] The second polymer portion may be composed of a plurality of polymers each having a plurality of different structural units. In this case, the structural units may be any of those exemplified as the structural units of the second polymer portion.

[0031] The peak top value derived from the second polymer portion is 1000 or more and 50000 or less. If it is 1000 or more, the mechanical properties tend to improve when added to the matrix resin, and if it is 50000 or less, the compatibility between the polyester resin, which is the first matrix resin, and the second matrix resin can be improved. The peak top value is preferably 1000 or more and 30000 or less, more preferably 1000 or more and 15000 or less. As described above, the peak top value can be measured by GPC using tetrahydrofuran as an eluent and polymethyl methacrylate as a standard sample. The above value indicates the relative molecular weight to the standard sample at the peak position derived from the second polymer portion.

[0032] In a chromatogram obtained by measuring the molecular weight of polymer A by GPC, the peak derived from the second polymer portion can be identified from the molecular weight of the second polymer portion calculated from the ratio of the integrated intensity derived from the terminal structure of the second polymer portion obtained by NMR measurement to the integrated intensity derived from the polymer main chain of the second polymer portion.

[0033] The content of the first polymer portion in a total of 100 parts by mass of the first polymer portion and the second polymer portion is preferably more than 20 parts by mass and not more than 90 parts by mass, more preferably more than 20 parts by mass and not more than 80 parts by mass, more preferably more than 20 parts by mass and not more than 70 parts by mass, more preferably more than 20 parts by mass and not more than 60 parts by mass, and more preferably more than 20 parts by mass and not more than 50 parts by mass, in order to further improve the compatibility between the first matrix resin and the second matrix resin when polymer A is added to the first matrix resin and the second matrix resin as a compatibilizer.

[0034] <1-3. Method for producing polymer A> The method for producing polymer A when it has a core-shell structure is not particularly limited, and it can be produced by a known method such as suspension polymerization, solution polymerization, or emulsion polymerization. Among them, from the viewpoint of ease of production, it is preferable to produce it by emulsion polymerization. That is, it is preferable that polymer A is a polymer obtained by emulsion polymerization of a monomer component constituting the second polymer portion in the presence of a polymer constituting the first polymer portion to be finally obtained. In addition, when carrying out emulsion polymerization, the monomer component may be added and polymerized all at once by batch polymerization, or may be added stepwise by dropwise polymerization.

[0035] More specifically, a monomer component constituting the second polymer portion can be added to a solution in which the polymer constituting the first polymer portion is dispersed in an arbitrary solvent, emulsified using various mixers, and a polymerization initiator can be added to polymerize.

[0036] A solution in which the polymer constituting the first polymer portion is dispersed in an arbitrary solvent can be obtained, for example, by adding the polymer constituting the first polymer portion to one or more solvents such as water, various alcohols such as isopropyl alcohol, ethanol, and methanol, acetone, methyl ethyl ketone, and diethyl ether, and stirring while applying shear. The proportion of the polymer constituting the first polymer portion in the dispersion solution is preferably 10% by mass or more in terms of excellent dispersibility, and is preferably 50% by mass or less in terms of handleability taking into account the viscosity of the dispersion solution.

[0037] When the monomer component constituting the second polymer portion is added to a solution in which the polymer constituting the first polymer portion is dispersed in an arbitrary solvent, a surfactant may be further added. Examples of the surfactant include anionic surfactants, cationic surfactants, and neutral surfactants. One type of surfactant may be used alone, or two or more types may be used in combination.

[0038] As the polymerization initiator, those generally used for radical polymerization can be used. Specific examples thereof include persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; oil-soluble azo compounds such as azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), and 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile; 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,2'-azobis{2-methyl-N-[2-(1-hydroxyethyl)]propionamide}, 2,2'-azobis{2-methyl-N-[2- water-soluble azo compounds such as 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] and its salts, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] and its salts, 2,2'-azobis{2-[1-(2-hydroxyethyl)-2-imidazolin-2-yl]propane} and its salts, 2,2'-azobis(2-methylpropynamidine) and its salts, and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]; and organic peroxides such as benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxy-2-ethylhexanoate, and t-butyl peroxyisobutyrate. The polymerization initiator may be used alone or in combination of two or more kinds.

[0039] Preferred radical polymerization methods in one embodiment of the present invention include, for example, a method in which polymerization is carried out using a water-soluble polymerization initiator, and a method in which polymerization is carried out by a redox reaction using an organic peroxide and a reducing agent such as ferrous sulfate or isoascorbic acid.

[0040] The amount of the polymerization initiator used is preferably 0.05 to 1.0 parts by mass relative to 100 parts by mass of the total of the monomers constituting the second polymer portion, and more preferably the lower limit is 0.1 parts by mass or more and the upper limit is 0.3 parts by mass or less. When a peroxide-based polymerization initiator is used, it can be used as a redox-based polymerization initiator in combination with a reducing agent. The amount of the reducing agent used is preferably 0.0001 to 1 part by mass relative to 100 parts by mass of the total of the monomer components constituting the second polymer portion.

[0041] The polymerization may be carried out using a known chain transfer agent such as n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, or α-methylstyrene dimer as a molecular weight regulator. The molecular weight of the second polymer portion and the value of the peak top derived from the second polymer portion can be made smaller by increasing the content of such a molecular weight regulator.

[0042] The amount of the molecular weight modifier used is preferably 0.5 to 10 parts by mass, more preferably 1 to 7 parts by mass, and even more preferably 1.5 to 6 parts by mass, relative to 100 parts by mass in total of the first polymer portion and the second polymer portion. Such an amount allows the molecular weight of the second polymer portion to be adjusted to a value within a range that improves the function as a compatibilizer for polymer A.

[0043] The reaction temperature is not particularly limited, but is usually from 45° C. to 80° C. The reaction time is not particularly limited, but is usually from 30 minutes to 300 minutes.

[0044] The latex of polymer A obtained by emulsion polymerization can be dried by spray drying or freeze drying, or coagulated, to recover the polymer powder. Among these, drying or coagulation by spray drying is preferred.

[0045] In the case of drying by spray drying, it is preferable to spray the latex of polymer A onto fine droplets and dry them by applying hot air to them. Any device such as a rotating disk type, a pressure nozzle type, or a two-fluid nozzle type may be used as a device for generating droplets.

[0046] When the latex of polymer A is dried by applying hot air, the hot air temperature is preferably 100° C. or more and 200° C. or less. When the hot air temperature is 100° C. or more, the latex can be sufficiently dried, and when the hot air temperature is 200° C. or less, thermal decomposition of the obtained powder can be reduced.

[0047] When coagulation is performed, the latex of polymer A is put into hot water in which a coagulant is dissolved, and polymer A is salted out, separated, purified, coagulated, and made wet, which is then dehydrated and dried. Examples of the coagulant include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate, and acids such as sulfuric acid, with calcium acetate being particularly preferred. These coagulants may be used alone or in combination of two or more, but when used in combination, it is preferable to select a combination that does not form a water-insoluble salt. For example, the combination of calcium acetate with sulfuric acid or its sodium salt is not preferable because it forms a water-insoluble calcium salt.

[0048] It is common technical knowledge that the polymerization mode of the first polymer portion and the second polymer portion of the polymer A changes depending on the production method thereof, but it is difficult to specify what the polymerization mode is. For example, it is considered that the polymerization mode of the polymer A obtained by emulsion polymerization of the monomer component constituting the second polymer portion in the presence of the polymer constituting the first polymer portion changes from that of the polymer A obtained by other methods, resulting in a difference in structure or properties. However, it is technically impossible or almost impractical to specify the structure or properties so as to clearly show such differences.

[0049] <1-4. Resin additives> The polymer A can be used as a resin additive such as a compatibilizer. The resin additive may be the polymer A itself, or may be mixed with any auxiliary. Examples of the auxiliary include known ones, such as flame retardants, anti-dripping agents, antioxidants, ultraviolet absorbers, light stabilizers, release agents, lubricants, sliding agents, colorants, fluorescent brighteners, phosphorescent pigments, fluorescent dyes, and antistatic agents.

[0050] [2. Resin composition] A resin composition according to one embodiment of the present invention includes a polymer A and a first matrix resin that is a polyester resin. The resin composition may further include a second matrix resin that is a resin different from the first matrix resin.

[0051] The content of polymer A relative to 100 parts by mass of the total of the first matrix resin and the second matrix resin is not particularly limited, but is preferably 0.1 to 30 parts by mass, and more preferably 5 to 20 parts by mass. If the content of polymer A is 0.1 part by mass or more, the compatibility of the first matrix resin and the second matrix resin is further improved, and if it is 30 parts by mass or less, the processability during production of the resin composition is excellent.

[0052] The resin composition according to one embodiment of the present invention may further contain other components. For example, known auxiliary agents may be blended as necessary to impart functionality or improve properties. Examples of such auxiliary agents include flame retardants, anti-dripping agents, antioxidants, UV absorbers, light stabilizers, release agents, lubricants, sliding agents, colorants, fluorescent brighteners, phosphorescent pigments, fluorescent dyes, and antistatic agents.

[0053] <2-1. First matrix resin> The first matrix resin is a polyester resin, and may be, for example, at least one resin selected from the group consisting of polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polybutylene succinate (PBS), polyhydroxyalkanoic acid (PHA), and polylactic acid (PLA). Recycled materials may also be used for these.

[0054] <2-2. Second matrix resin> The second matrix resin is not particularly limited as long as it is a resin different from the first matrix resin, but for example, a polystyrene-containing resin such as polystyrene, high impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene copolymer (ABS) can be used. Recycled materials may also be used for these. From the viewpoint of improving compatibility, it is preferable that at least a part of the constituent units constituting the second matrix resin is the same as at least a part of the constituent units of the second polymer portion in polymer A.

[0055] The content of the first matrix resin relative to 100 parts by mass of the total of the first matrix resin and the second matrix resin is not particularly limited, but is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and more preferably 25 parts by mass or more, while the content of the first matrix resin is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and more preferably 75 parts by mass or less.

[0056] <2-3. Method for producing resin composition> The resin composition can be produced by mixing or melt-kneading the polymer A, the first matrix resin, and the second matrix resin in powder form, without any particular limitation. For mixing or melt-kneading, a Henschel mixer, a Banbury mixer, a single-screw extruder, a twin-screw extruder, a two-roll machine, a kneader, a Brabender, or the like can be used.

[0057] 3. Molded body The resin composition according to one embodiment of the present invention can be molded into a molded article. The resin composition according to one embodiment of the present invention may be mixed with other materials and then molded into a molded article. That is, the molded article may contain the resin composition according to one embodiment of the present invention.

[0058] The shape of the molded product is not particularly limited, and may be various shapes such as a resin plate, a sheet, a film, a cable, a fiber, an irregular shape, etc. As a molding method for the molded product, a known method can be used, and examples thereof include compression molding, transfer molding, injection molding, blow molding, vacuum molding, extrusion molding, lamination molding, and calendar molding.

[0059] [4. Summary] As described above, the present invention has the following aspects.

[0060] The polymer according to aspect 1 of the present invention is a polymer having a first polymer portion and a second polymer portion, the first polymer portion being composed of a polyester-based polymer, the second polymer portion being a polymer different from the first polymer portion and having a constituent unit derived from a (meth)acrylate monomer, and in molecular weight measurement by gel permeation chromatography using tetrahydrofuran as an eluent and polymethyl methacrylate as a standard sample, the peak top value derived from the second polymer portion is 1,000 or more and 50,000 or less.

[0061] The polymer according to aspect 2 of the present invention may be the polymer of aspect 1, in which the content of the constitutional unit derived from the (meth)acrylate monomer per 100 parts by mass of the second polymer portion is 20 parts by mass or more.

[0062] The polymer according to aspect 3 of the present invention may be the polymer of aspect 1 or 2, which has a core-shell structure, in which the first polymer portion constitutes a shell portion of the core-shell structure and the second polymer portion constitutes a core portion of the core-shell structure.

[0063] The polymer according to aspect 4 of the present invention is the polymer of any one of aspects 1 to 3, wherein the content of the first polymer portion is more than 20 parts by mass and not more than 90 parts by mass, relative to 100 parts by mass of the total of the first polymer portion and the second polymer portion.

[0064] The polymer according to aspect 5 of the present invention may be obtained by emulsion polymerization of a monomer component constituting the second polymer portion in the presence of a polymer constituting the first polymer portion in any one of aspects 1 to 4.

[0065] A resin composition according to a sixth aspect of the present invention contains the polymer according to any one of the first to fifth aspects and a polyester resin as a first matrix resin.

[0066] The resin composition according to a seventh aspect of the present invention may be the resin composition according to the sixth aspect, further comprising a second matrix resin, the second matrix resin being different from the first matrix resin.

[0067] A molded article according to an eighth aspect of the present invention comprises the resin composition according to the sixth or seventh aspect. EXAMPLES

[0068] An embodiment of the present invention will now be described with reference to the following examples. In the examples, "parts" refers to "parts by mass."

[0069] <Tensile modulus, tensile stress, tensile elongation> A tensile test was carried out using a Tensilon universal testing machine (model name "RTC-1250A-PL", manufactured by Orientec Co., Ltd.) in accordance with JIS K7139 to measure the tensile modulus, tensile stress and tensile elongation of the molded body.

[0070] <Impact properties> The impact properties were evaluated by measuring the Charpy strength of a 4 mm thick molded product at 23°C in accordance with JIS K7111.

[0071] <Peak top value> For the polymer according to one embodiment of the present invention or the polymer according to the comparative example, a GPC measurement was carried out under the following conditions, and the value of the peak top derived from the second polymer portion was calculated. Equipment: HLC-8220 (Tosoh Corporation) Column: TSK GUARD COLUMN SUPER HH (4.6 x 35 mm, Tosoh Corporation) and two TSK-GEL SUPER HM-H (6.0 x 150 mm, Tosoh Corporation) connected in series Detector: Refractive index (RI) detector Column and detector temperature: 40°C Eluent: Tetrahydrofuran Flow rate: 0.6mL / min Sample concentration: 2 mg / mL (tetrahydrofuran solution) Standard substance: polymethyl methacrylate (Polymer Laboratories; Mp (peak molecular weight) = 141,500, 55,600, 11,100, 1,590)

[0072] (Production Example 1) As an aqueous dispersion solution of the polymer (hereinafter also referred to as "first polymer") constituting the first polymer portion, 300 parts of Nichigo Polyester (registered trademark) WR-905 (manufactured by Mitsubishi Chemical Corporation: solid content 20%), 50 parts of styrene (St), 45 parts of methyl methacrylate (MMA), and 5 parts of butyl acrylate (BA) as radical polymerizable monomers, and 3 parts of normal octyl mercaptan (manufactured by Tokyo Chemical Industry Co., Ltd.) as a chain transfer agent were mixed and emulsified with a homomixer to obtain a pre-emulsion liquid of the radical polymerizable monomer. The radical polymerizable monomer constitutes the second polymer portion.

[0073] The obtained pre-emulsion liquid and 180 parts of deionized water were added to a flask equipped with a stirrer, a reflux condenser, and a temperature control device, and the temperature was raised to 50°C while nitrogen bubbling was performed at a flow rate of 200 mL per minute, and the temperature was maintained for 1 hour. 0.7 parts of Percumyl (registered trademark) P (manufactured by NOF Corp.) as a polymerization initiator, 0.002 parts of ferrous sulfate, 0.006 parts of sodium ethylenediaminetetraacetate (EDTA), 0.3 parts of sodium formaldehyde sulfoxylate, and 10 parts of deionized water as reducing agents were added, and the nitrogen flow was switched to initiate polymerization. After 1 hour, the temperature was raised to 60°C, and the mixture was maintained for 2 hours and then cooled to obtain a latex of polymer A1 according to one embodiment of the present invention. The obtained polymer A1 latex was added to 460 parts of deionized water containing 5 parts by mass of calcium acetate, coagulated, washed with water, dehydrated, and dried to obtain polymer A1 in the form of powder. Polymer A1 functions as a compatibilizer.

[0074] (Production Examples 2 to 6) Polymers A2 to A5 according to one embodiment of the present invention and polymer B1 according to a comparative example were obtained by the same production method as in Production Example 1, except that the amount of the first polymer portion and the amount of the chain transfer agent were changed as shown in Table 1 below.

[0075] Example 1 65 parts of polylactic acid (PLA, manufactured by NatureWorks: Ingeo Biopolymer3001D) as the first matrix resin, 35 parts of high impact polystyrene (HIPS, manufactured by Toyo Styrene Co., Ltd.: Toyo Styrol (registered trademark) H350) as the second matrix resin, and 5 parts of the polymer A1 manufactured in Manufacturing Example 1 were placed in a polyethylene bag. The polyethylene bag was shaken well by hand to hand blend, and then melt-kneaded at 230°C using a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., product name: TEM35B), and the extruded strand was cut to obtain pellets.

[0076] The obtained pellets were molded using an injection molding machine (Toshiba Machine Co., Ltd., product name: IS100EN) at a molding temperature of 230°C and a mold temperature of 60°C to produce a dumbbell-shaped molded body with a thickness of 4 mm conforming to JIS K7139 and JIS K7111, thereby obtaining a molded body according to Example 1. A tensile test and an impact test were carried out on the molded body. The tensile modulus of the molded body in the tensile test was 2.1 GPa, the tensile stress was 31 MPa, and the tensile elongation was 15.7%. The result of the impact test was 2.4 kJ / m at 23°C. 2 It was.

[0077] (Examples 2 to 6) Molded articles were obtained and evaluated in the same manner as in Example 1, except that the types and ratios of the first and second matrix resins and the type of polymer used as a compatibilizer were changed as shown in Table 2 below. In Examples 3 to 6 and Comparative Example 2, polybutylene terephthalate (PBT, Novaduran (registered trademark) 5010R5, manufactured by Mitsubishi Engineering Plastics Corporation) was used as the first matrix resin. Polystyrene (PS, Toyo Styrol GP NW1C, manufactured by Toyo Styrene Corporation) was used as the second matrix resin.

[0078] Comparative Example 1 A resin composition and a molded article were produced in the same manner as in Example 1, except that polymer A1 obtained in Production Example 1 was not added, to obtain a molded article according to Comparative Example 1. A tensile test and an impact test were carried out on the molded article. The tensile modulus of the molded article in the tensile test was 2.0 GPa, the tensile stress was 28 MPa, and the tensile elongation was 3.8%. The result of the impact test was 1.9 kJ / m at 23°C. 2 It was.

[0079] (Comparative Examples 2 and 3) Molded bodies were obtained and evaluated in the same manner as in Example 1, except that the types and ratios of the first matrix resin and the second matrix resin, and the type of polymer used as the compatibilizer were changed as shown in Table 2 below.

[0080] [Table 1]

[0081] [Table 2]

[0082] In Examples 1 and 2, in which a polymer having a peak top value derived from the second polymer portion in the range of 1000 to 50000 was added to the matrix resin, the impact test value, tensile modulus, tensile stress, and tensile elongation all showed values ​​equal to or higher than those in Comparative Example 1, in which no polymer was added. The same was true when Examples 3 to 6 were compared with Comparative Example 2.

[0083] On the other hand, in Comparative Example 3 in which polymer B1 having a peak top value of 90,000 derived from the second polymer portion was added to the matrix resin, the tensile elongation was particularly lower than that in Comparative Example 1 in which no polymer was added. [Industrial Applicability]

[0084] The polymer according to one embodiment of the present invention can be suitably used as a compatibilizer that can reduce phase separation of resins when two or more types of resins are mixed, and that has excellent tensile elongation when a resin composition containing the polymer is molded into a molded article.

Claims

1. A polymer having a first polymer portion and a second polymer portion, the first polymer portion is composed of a polyester-based polymer, the second polymer portion is a polymer different from the first polymer portion and has a constitutional unit derived from a (meth)acrylate monomer; A polymer, wherein in molecular weight measurement by gel permeation chromatography using tetrahydrofuran as an eluent and polymethyl methacrylate as a standard sample, the peak top value derived from the second polymer portion is 1,000 or more and 50,000 or less.

2. The polymer according to claim 1 , wherein the content of the structural unit derived from the (meth)acrylate monomer relative to 100 parts by mass of the second polymer portion is 20 parts by mass or more.

3. It has a core-shell structure, the first polymer portion constitutes a shell portion of the core-shell structure; The polymer of claim 1 , wherein the second polymer portion constitutes a core portion of the core-shell structure.

4. The polymer according to claim 1 , wherein the content of the first polymer portion is more than 20 parts by mass and not more than 90 parts by mass, relative to 100 parts by mass of the total of the first polymer portion and the second polymer portion.

5. 2. The polymer according to claim 1, obtained by emulsion polymerization of a monomer component constituting said second polymer portion in the presence of a polymer constituting said first polymer portion.

6. A resin composition comprising the polymer according to any one of claims 1 to 5 and a polyester resin as a first matrix resin.

7. The resin composition according to claim 6 , further comprising a second matrix resin, the second matrix resin being different from the first matrix resin.

8. A molded article comprising the resin composition according to claim 6.

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