Master batch, and method for manufacturing the same

Abstract

To provide a master batch which suppresses segregation of an additive, and has stable concentration.SOLUTION: A master batch contains at least one kind of a thermoplastic resin, and a solid additive having a compression degree of 10% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a masterbatch used in an interlayer film for laminated glass, and a method for producing the same. [Background technology]

[0002] Resin compositions used in various applications, such as interlayer films for laminated glass, are composed of thermoplastic resins to which various additives, such as antioxidants, ultraviolet absorbers, and light stabilizers, have been added. From the viewpoints of workability and mixability with thermoplastic resins, additives are sometimes added to the thermoplastic resins in the form of masterbatches (see, for example, Patent Document 1). Masterbatches are formed by blending additives into thermoplastic resins in advance at a higher concentration than in the intended composition formulation, and are generally formed into pellets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 189335 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the studies of the present inventors, when a solid additive is blended into a masterbatch, the solid additive may segregate during the process of mixing the thermoplastic resin and the solid additive, resulting in variations in the concentration of the solid additive. Variations in the concentration in the masterbatch may result in uneven distribution of the solid additive in the interlayer film for laminated glass or the resin composition, or the additive concentration may deviate from the designed value, causing problems.

[0005] Therefore, an object of the present invention is to provide a masterbatch in which segregation of additives is suppressed. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that the above problems can be solved by adjusting the degree of compression of the solid additives to be blended into the masterbatch to a certain value or less, and have completed the present invention as described below. That is, the present invention provides the following [1] to

[21] . [1] A masterbatch containing a thermoplastic resin and at least one solid additive having a compressibility of 10% or less. [2] The masterbatch according to [1] above, which is spherical, cylindrical, or prismatic. [3] The masterbatch according to [1] or [2] above, which is a pellet having an average minor axis of 1 mm or more and 5 mm or less. [4] The masterbatch according to any one of the above [1] to [3], which is in the form of pellets having an average major axis of 2 mm or more and 10 mm or less. [5] The masterbatch according to any one of the above [1] to [4], wherein the solid additive contains at least one of an ultraviolet absorber and an antioxidant. [6] The masterbatch according to any one of the above [1] to [5], further comprising a liquid additive. [7] The masterbatch according to [6] above, wherein the content of the liquid additive is 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the thermoplastic resin. [8] The masterbatch according to any one of the above [1] to [7], wherein the content of the solid additive is 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the thermoplastic resin. [9] The masterbatch according to any one of the above [1] to [8], wherein the total content of the additives contained in the masterbatch is 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the thermoplastic resin.

[10] The masterbatch according to any one of the above [1] to [9], wherein the glass transition temperature of the thermoplastic resin is 40°C or higher and 75°C or lower.

[11] The masterbatch according to any one of the above [1] to

[10] , wherein the thermoplastic resin is an ionomer resin.

[12] The masterbatch according to

[11] above, wherein the ionomer resin comprises a structural unit (A) derived from (meth)acrylic acid, a structural unit (B) of a neutralized (meth)acrylic acid, and a structural unit (C) derived from ethylene.

[13] The masterbatch according to

[12] above, wherein the total content of the structural units (A) and (B) in the ionomer resin is 10% by mass or more and 25% by mass or less, based on the total amount of the structural units constituting the ionomer resin.

[14] The masterbatch according to the above

[12] or

[13] , wherein the content of the structural unit (B) in the ionomer resin is 4% by mass or more and 18% by mass or less, based on the total amount of structural units constituting the ionomer resin.

[15] The masterbatch according to any one of the above

[12] to

[14] , wherein the structural unit (B) contains any one of sodium, magnesium, and zinc.

[16] The masterbatch according to any one of the above [1] to

[15] , wherein the thermoplastic resin is an ethylene-(meth)acrylic acid copolymer.

[17] The ethylene-(meth)acrylic acid copolymer contains a structural unit (A) derived from (meth)acrylic acid and a structural unit (C) derived from ethylene, The masterbatch according to

[16] above, wherein the content of the structural unit (A) is 10% by mass or more and 25% by mass or less, based on the total amount of structural units constituting the ethylene-(meth)acrylic acid copolymer.

[18] A method for producing a masterbatch, comprising the step of blending at least one solid additive having a compressibility of 10% or less with a thermoplastic resin to obtain a thermoplastic resin composition.

[19] The method for producing the masterbatch according to

[18] above, further comprising the step of extrusion molding the thermoplastic resin composition.

[20] The method for producing a masterbatch according to

[19] above, wherein the extrusion molding is carried out in an extruder, and the maximum temperature in the extruder is 150°C or higher and 220°C or lower.

[21] The method for producing a masterbatch according to any one of the above

[18] to

[20] , wherein the thermoplastic resin is supplied in the form of pellets having a minor axis of 1 mm or more and 5 mm or less and a major axis of 2 mm or more and 10 mm or less, and mixed with the solid additive. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a masterbatch in which segregation of additives is suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, the present invention will be described in detail with reference to embodiments. <Masterbatch> The masterbatch of the present invention contains a thermoplastic resin and at least one solid additive having a compressibility of 10% or less. The masterbatch of the present invention will be described in detail below.

[0009] [Solid additives] As described above, the masterbatch of the present invention contains at least one solid additive having a compressibility of 10% or less. In the present invention, the use of a solid additive having a compressibility of 10% or less prevents segregation of the solid additive in the masterbatch, thereby stabilizing the additive concentration. As a result, the performance of the interlayer film for laminated glass or the resin composition produced using the masterbatch, as well as the optical properties such as haze and visible light transmittance, can be stabilized.

[0010] On the other hand, if the compression rate of the solid additive exceeds 10%, the solid additive may concentrate in one area and cause segregation when it is mixed with the thermoplastic resin during the masterbatch manufacturing process. For example, in extrusion molding, the solid additive is likely to pass through the thermoplastic resin and be supplied to the die before the thermoplastic resin, and the concentration of the solid additive in the masterbatch in the early stages of production immediately after the start of raw material supply is likely to be higher than in the later stages of production.

[0011] From the viewpoint of more effectively suppressing segregation, the degree of compression of the solid additive is preferably 8% or less, more preferably 7% or less, and even more preferably 6% or less. Furthermore, the degree of compression of the solid additive is not particularly limited as long as it is 0% or more, but in practice, 1% or more is preferred, and 2% or more is more preferred. The degree of compression can be adjusted by the shape of the solid additive used as a raw material, and it is easier to reduce the degree of compression with granulated solid additives in the form of particles, granules, flakes, etc., than with powder-like solid additives. The degree of compression means the degree of powder compression, and is a value measured by the method described in the Examples.

[0012] The solid additive is an additive that is solid at room temperature (23°C) and normal pressure (1 atmosphere). The solid additive is not particularly limited as long as it is an additive that can be blended into a thermoplastic resin, and examples thereof include ultraviolet absorbers, antioxidants, coupling agents, light stabilizers, antistatic agents, surfactants, colorants, foaming agents, lubricants, crystal nucleating agents, crystallization accelerators, crystallization retarders, catalyst deactivators, heat absorbers, heat reflectors, heat dissipation agents, inorganic fillers, organic fillers, impact modifiers, slip agents, crosslinking agents, crosslinking aids, processing aids, mold release agents, hydrolysis inhibitors, antiblocking agents, antifogging agents, flame retardants, flame retardant aids, light diffusing agents, antibacterial agents, antifungal agents, and dispersants. Among these, at least one of ultraviolet absorbers and antioxidants is preferred. Ultraviolet absorbers and antioxidants are widely used in resin compositions for interlayer films for laminated glass and other applications. Therefore, by incorporating at least one of an ultraviolet absorber and an antioxidant as a solid additive into a masterbatch, the practicality of the masterbatch is improved.

[0013] (ultraviolet absorber) Examples of the ultraviolet absorber used in the solid additive include a compound having a malonic acid ester skeleton, a compound having an oxalic acid anilide skeleton, a compound having a benzotriazole skeleton, a compound having a benzophenone skeleton, a compound having a triazine skeleton, a compound having a benzoate skeleton, a compound having a hindered amine skeleton, etc. Among these, a compound having a benzotriazole skeleton (benzotriazole-based compound) is preferred. UV absorbers absorb UV rays contained in sunlight, etc., and prevent the resin film from deteriorating due to exposure to sunlight, etc., thereby improving durability. Therefore, a masterbatch containing a UV absorber is preferably blended into a resin composition used for an interlayer film for laminated glass or in an application where the film is exposed to sunlight.

[0014] Benzotriazole compounds include compounds represented by the following formula (I). [ka] (In the above formula, R1 to R8 are each independently a hydrogen atom, a halogen atom, or an organic group having 1 to 20 carbon atoms.)

[0015] In the above formula (I), R1 is preferably an organic group having 4 to 20 carbon atoms, and more preferably an organic group having 4 to 10 carbon atoms. R1 may contain an oxygen atom, a nitrogen atom, a sulfur atom, etc., but is preferably a hydrocarbon group. That is, R1 is more preferably a hydrocarbon group having 4 to 20 carbon atoms, even more preferably a hydrocarbon group having 4 to 10 carbon atoms, and among these, an alkyl group or an aralkyl group is even more preferred. Furthermore, R1 preferably has either a quaternary carbon atom or an aromatic ring, or both. Furthermore, in R1, the carbon atom directly bonded to the benzene ring constituting the benzotriazole skeleton is more preferably a quaternary carbon atom, more specifically, a tert-butyl group or a 1-methyl-1-phenylethyl group is particularly preferred.

[0016] In the formula (I), R2 to R8 are each independently a hydrogen atom, a halogen atom, or an organic group having 1 to 20 carbon atoms. The halogen atom in the formula (I) is preferably a chlorine atom. The organic group in R2 to R8 may contain an oxygen atom, a nitrogen atom, a sulfur atom, or the like, or may be a hydrocarbon group. In the formula (I), R2, R4, R5, R6, R7, and R8 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, an alkylamino group, an anilino group, an acylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, an alkylthio group, or an arylthio group, and more preferably a hydrogen atom or a halogen atom. It is further preferred that R2, R4, R5, R6, R7, and R8 are all hydrogen atoms, or that R2, R4, R5, R7, and R8 are hydrogen atoms and R6 is a chlorine atom.

[0017] R3 in the above formula (I) is a hydrogen atom or an organic group having 1 to 20 carbon atoms. The organic group may contain an oxygen atom, a nitrogen atom, a sulfur atom, etc., or may be a hydrocarbon group. R3 is preferably a hydrocarbon group having 1 to 10 carbon atoms, or an organic group having an ester structure. Preferred examples of the organic group having an ester structure include alkoxycarbonylalkyl groups having 4 to 20 carbon atoms. R3 is preferably an alkyl group, an aralkyl group, or an alkoxycarbonylalkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a sec-butyl group, an isobutyl group, a 1,1,3,3-tetramethylbutyl group, a 1-methyl-1-phenylethyl group, a propionyl group, and a methoxycarbonylethyl group. Among the above, R3 is preferably an alkyl group, or a group having either a quaternary carbon atom and an aromatic ring, or both, and specifically, a methyl group, a 1-methyl-1-phenylethyl group, or a 1,1,3,3-tetramethylbutyl group is particularly preferred.

[0018] Specific examples of benzotriazole compounds include 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, octyl 3-[3-tert-butyl-5-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate, methyl 3-(5-chloro-2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenylpropionate, 2-(3,5-di-tert-amyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3-dimethylbenzylphenyl-5-(1,1,3,3-tetramethylbutyl)]-2H-benzotriazole, and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole.

[0019] In addition, commercially available benzotriazole compounds may be used, and examples thereof include TINUVIN 326, TINUVIN 327, Tinuvin 928, and Tinuvin 234 (trade names, manufactured by BASF), Eversorb 109 and Eversorb 88 (trade names, manufactured by Everlight Chemical), and RIASORB UV-326, UV-327, UV-928, and UV-234 (trade names, manufactured by Rianlon).

[0020] (antioxidant) Antioxidants used in solid additives include phenolic compounds, phosphorus-based compounds, and sulfur-based compounds. Antioxidants prevent oxidative deterioration of the interlayer film for laminated glass and the resin composition in which the masterbatch is blended, thereby improving durability. Among these, phenolic compounds are preferred from the viewpoint of improving durability.

[0021] Examples of the phenolic compounds include 2,6-di-t-butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-t-butylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), 4,4'-butylidene-bis-(3-methyl-6-t-butylphenol), 1,1,3-tris-(2-methyl-hydroxy-5 ... tert-butylphenyl)butane, tetrakis[methylene-3-(3',5'-butyl-4-hydroxyphenyl)propionate]methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-t-butylphenol)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,3'-t-butylphenol) butylic acid glycol ester, and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. Among these, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is preferred. Commercially available antioxidants can also be used, such as "Irganox 1010" from BASF and "RIANOX 1010" from Rianlon.

[0022] Examples of the phosphorus-based compound include 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 2,2'-methylenebis(4,6-di-tert-butylphenyl)2-ethylhexyl phosphite, tris(nonylphenyl)phosphite, and tris(2,4-di-tert-butylphenyl)phosphite.

[0023] Examples of the sulfur-based compound include dialkyl thiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate, and β-alkyl mercaptopropionate esters of polyols such as pentaerythritol tetra(β-dodecyl mercaptopropionate). The antioxidants may be used alone or in combination of two or more.

[0024] In the masterbatch, the content of the solid additive is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the thermoplastic resin. A solid additive content of 1 part by mass or more allows a small amount of the masterbatch to be used to blend an appropriate amount of solid additive into an interlayer film for laminated glass or a resin composition produced using the masterbatch. Furthermore, a solid additive content of 20 parts by mass or less can avoid separation due to viscosity differences during production, for example, during extrusion, making segregation of the solid additive even less likely to occur. The content of the solid additive is more preferably 1 part by mass or more and 15 parts by mass or less, and even more preferably 3 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin.

[0025] The solid additive contained in the masterbatch is preferably one or both of an ultraviolet absorber and an antioxidant. Therefore, the total content of the ultraviolet absorber and antioxidant contained in the masterbatch is preferably 1 part by mass or more and 20 parts by mass or less, more preferably 1 part by mass or more and 15 parts by mass or less, and even more preferably 3 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin.

[0026] [Liquid additive] The masterbatch may further contain a liquid additive. The liquid additive is an additive that is liquid at room temperature (23°C) and normal pressure (1 atmosphere). By containing the liquid additive, the masterbatch becomes less likely to allow the solid additive to slide against the thermoplastic resin during the manufacturing process, making the solid additive even less likely to segregate.

[0027] The liquid additive is not particularly limited as long as it can be incorporated into a thermoplastic resin. Examples of the liquid additive include ultraviolet absorbers, antioxidants, coupling agents such as silane coupling agents, light stabilizers, plasticizers, antistatic agents, surfactants, colorants, foaming agents, lubricants, crystal nucleating agents, crystallization accelerators, crystallization retarders, catalyst deactivators, heat absorbers, heat reflectors, heat dissipation agents, impact resistance modifiers, slip agents, crosslinking agents, crosslinking aids, processing aids, release agents, hydrolysis inhibitors, antiblocking agents, antifogging agents, flame retardants, flame retardant aids, light diffusing agents, antibacterial agents, antifungal agents, and dispersants. Among these, the liquid additive is preferably at least one of a silane coupling agent and a light stabilizer. Light stabilizers are widely used in interlayer films for laminated glass and resin compositions for other applications exposed to sunlight. Furthermore, the use of a silane coupling agent in an interlayer film for laminated glass can improve adhesion to glass members.

[0028] (Silane coupling agent) Examples of silane coupling agents used as liquid additives include those having a functional group such as a group containing a polymerizable carbon-carbon double bond, such as a vinyl group or a (meth)acryloyl group, an amino group or an epoxy group, and a hydrolyzable group such as an alkoxy group.

[0029] Examples of silane coupling agents having a polymerizable carbon-carbon double bond include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, and 3-acryloxypropyltriethoxysilane. Examples of silane coupling agents having an amino group include N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, and N-phenyl-3-aminopropyltrimethoxysilane. Examples of silane coupling agents having an epoxy group include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. The masterbatch may contain one type of silane coupling agent alone, or may contain two or more types of silane coupling agents. From the viewpoint of enhancing adhesiveness, the silane coupling agent is preferably a silane coupling agent having an amino group, and among these, a silane coupling agent having an ethylenediamine structure such as N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is preferred.

[0030] (light stabilizer) The light stabilizer is preferably a hindered amine light stabilizer, which prevents deterioration of the interlayer film for laminated glass and the resin composition due to exposure to ultraviolet rays contained in sunlight and the like. Examples of the hindered amine light stabilizer include a hindered amine light stabilizer in which an alkyl group, an alkoxy group, or a hydrogen atom is bonded to a nitrogen atom of a piperidine structure.From the viewpoint of further suppressing deterioration, a hindered amine light stabilizer in which an alkyl group or an alkoxy group is bonded to a nitrogen atom of a piperidine structure is preferred.The hindered amine light stabilizer is preferably a hindered amine light stabilizer in which an alkyl group is bonded to a nitrogen atom of a piperidine structure, and is also preferably a hindered amine light stabilizer in which an alkoxy group is bonded to a nitrogen atom of a piperidine structure. The light stabilizer may be used alone or in combination of two or more kinds.

[0031] Examples of the hindered amine light stabilizer in which an alkyl group is bonded to the nitrogen atom of the piperidine structure include "Tinuvin 765" manufactured by BASF. Furthermore, an example of the hindered amine light stabilizer in which an alkoxy group is bonded to the nitrogen atom of the piperidine structure is "ADEKA STAB LA-81" manufactured by ADEKA Corporation. Examples of the hindered amine light stabilizer in which a hydrogen atom is bonded to the nitrogen atom of the piperidine structure include "Hostavin N24" manufactured by Clariant. The hindered amine light stabilizer may be used as a solid additive, and "ADEKA STAB LA-77Y" manufactured by ADEKA Corporation, which is a hindered amine light stabilizer having an alkoxy group bonded to a nitrogen atom of a piperidine structure, may be used as a solid additive.

[0032] In the masterbatch, the content of the liquid additive is preferably 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the thermoplastic resin. When the content of the liquid additive is 1 part by mass or more, segregation of the solid additive is further reduced. Furthermore, an appropriate amount of the liquid additive can be blended into the interlayer film for laminated glass or resin composition produced from the masterbatch with a small amount of masterbatch. Furthermore, when the content of the liquid additive is 10 parts by mass or less, separation due to viscosity differences during production, for example, during extrusion, can be avoided, and segregation of the solid additive in the masterbatch and uneven distribution of the liquid additive are further reduced. The content of the liquid additive is more preferably 1 part by mass or more and 5 parts by mass or less, and even more preferably 1 part by mass or more and 3 parts by mass or less, per 100 parts by mass of the thermoplastic resin.

[0033] The liquid additive contained in the masterbatch is preferably one or both of a silane coupling agent and a light stabilizer. Therefore, the total content of the silane coupling agent and the light stabilizer contained in the masterbatch is preferably 1 part by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 5 parts by mass or less, and even more preferably 1 part by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin.

[0034] The total content of additives in the masterbatch (i.e., the total content of solid additives and liquid additives) is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the thermoplastic resin. When the content of additives is 1 part by mass or more, an appropriate amount of additive can be blended into the interlayer film for laminated glass or resin composition produced from the masterbatch with a small amount of masterbatch. Furthermore, when the content of additives is 20 parts by mass or less, separation due to viscosity differences during production, for example, during extrusion, can be avoided, and segregation or uneven distribution of the additives in the masterbatch is less likely to occur. The total content of the additives is more preferably 1 part by mass or more and 15 parts by mass or less, and even more preferably 4 parts by mass or more and 12 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin.

[0035] [Thermoplastic resin] The thermoplastic resin contained in the masterbatch is not particularly limited as long as it is a thermoplastic resin that can be used in interlayer films for laminated glass and resin compositions for various applications. Examples include polyolefin resins, polyester resins, polycarbonate resins, polystyrene, styrene resins such as acrylonitrile-styrene copolymers, polyamide resins, polyurethane resins, acrylic resins, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetal resins, ethylene-vinyl acetate copolymer resins, ethylene-unsaturated carboxylic acid copolymers such as ethylene-(meth)acrylic acid copolymers, ionomer resins, thermoplastic elastomers, polylactic acid, biodegradable polymers such as polybutyl succinate, and the like.

[0036] Furthermore, from the viewpoint of being suitable for use in an interlayer film for laminated glass, among the above, polyvinyl acetal resins, ethylene-vinyl acetate copolymer resins, ionomer resins, polyurethane resins, thermoplastic elastomers, and ethylene-unsaturated carboxylic acid copolymers are preferred, and among these, ethylene-(meth)acrylic acid copolymers or ionomer resins are more preferred, with ionomer resins being particularly preferred. Ethylene-unsaturated carboxylic acid copolymers, such as ethylene-(meth)acrylic acid copolymers, or ionomer resins are often supplied as raw materials in pellet form, making them difficult to mix evenly with solid additives in extruders. However, by using specific solid additives as described above, they can be mixed evenly with the solid additives, reducing segregation. Furthermore, the use of these resins improves the miscibility and compatibility of masterbatches with ionomer resins, making them suitable for use in interlayer films for laminated glass containing ionomer resins. In particular, the use of ionomer resins in masterbatches further improves compatibility, making it easier to improve the optical properties of interlayer films for laminated glass. Furthermore, the use of ionomer resins also improves mechanical properties, such as bending rigidity, of interlayer films for laminated glass. On the other hand, the use of ethylene-unsaturated carboxylic acid copolymers, such as ethylene-(meth)acrylic acid copolymers, reduces the viscosity during masterbatch production, making it easier to incorporate solid additives more evenly into the masterbatch. In the masterbatch, the thermoplastic resin may be used alone or in combination of two or more kinds.

[0037] (glass transition temperature) The thermoplastic resin used in the masterbatch preferably has a glass transition temperature (Tg) of 40°C or higher and 75°C or lower. When the thermoplastic resin has a Tg of 40°C or higher, the mechanical strength of the interlayer film for laminated glass and resin composition produced using the masterbatch tends to be high. Therefore, even when these interlayer films for laminated glass and resin compositions are used, for example, exposed to an outdoor environment and at temperatures above a certain level, they can maintain high rigidity regardless of the temperature environment. Furthermore, when the Tg of the thermoplastic resin is 75°C or lower, a certain level of flexibility can be easily imparted to the interlayer film for laminated glass and resin composition produced using the masterbatch. The glass transition temperature (Tg) of the thermoplastic resin is more preferably 50° C. or higher, even more preferably 55° C. or higher, even more preferably 58° C. or higher, and even more preferably 60° C. or higher. The glass transition temperature (Tg) of the interlayer film is more preferably 73° C. or lower, even more preferably 71° C. or lower.

[0038] The glass transition temperature can be adjusted by the composition of the thermoplastic resin. For example, in the case of the ionomer resin described below, the glass transition temperature can be increased by increasing the amount of the structural unit (B) of the neutralized unsaturated carboxylic acid. The glass transition temperature can also be increased by using specific metal ions contained in the structural unit (B). Furthermore, the glass transition temperature can also be increased by reducing the amount of structural units derived from alkyl (meth)acrylate. The glass transition temperature can be determined by measuring the viscoelasticity using a dynamic viscoelasticity measuring device and reading the peak temperature of the loss tangent tanδ obtained from the viscoelasticity measurement results. The detailed measurement conditions are as described in the Examples.

[0039] (ionomer resin) Next, we will explain in detail about ionomer resins that can be suitably used as thermoplastic resins. Examples of ionomer resins include ionomer resins of ethylene-unsaturated carboxylic acid copolymers. Ionomer resins are typically resins obtained by neutralizing ethylene-unsaturated carboxylic acid copolymers with metal ions. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, and monoethyl maleate. In the ionomer resin, the unsaturated carboxylic acid may be used alone or in combination of two or more. Among these, acrylic acid and methacrylic acid are preferred. Therefore, the ionomer resin is preferably an ionomer resin of an ethylene-(meth)acrylic acid copolymer. Note that (meth)acrylic acid means at least either methacrylic acid or acrylic acid, and the same applies to similar terms below.

[0040] Examples of metal ions include lithium, potassium, sodium, silver, copper, calcium, magnesium, titanium, zinc, aluminum, barium, beryllium, strontium, tin, lead, iron, cobalt, nickel, cadmium, and mercury ions. Among these, at least one of sodium, magnesium, and zinc is preferred, at least one of magnesium and zinc is more preferred, and magnesium is particularly preferred. The metal ions may be used alone or in combination of two or more. Using at least one of magnesium and zinc, and particularly magnesium, as the metal ion forms an appropriate crosslinked structure, which facilitates increasing the glass transition temperature of the interlayer film and facilitating increasing mechanical strength such as bending rigidity.

[0041] When the ionomer resin is an ethylene-unsaturated carboxylic acid copolymer, it typically contains a structural unit (A) derived from an unsaturated carboxylic acid, a structural unit (B) derived from a neutralized product of the unsaturated carboxylic acid, and a structural unit (C) derived from ethylene. In particular, when the ionomer resin is an ethylene-(meth)acrylic acid copolymer, it typically contains a structural unit (structural unit (A)) derived from (meth)acrylic acid, a structural unit (structural unit (B)) derived from a neutralized product of (meth)acrylic acid, and a structural unit (C) derived from ethylene. By containing these structural units (A), (B), and (C), the ionomer resin is likely to have excellent mechanical strength, such as bending rigidity.

[0042] The monomer constituting the structural unit (A) is not particularly limited as long as it is an unsaturated carboxylic acid, but is preferably at least one of acrylic acid and methacrylic acid. Among these, methacrylic acid is more preferable from the viewpoint of bending rigidity and adhesiveness. The structural unit (A) is a structural unit that is not neutralized with metal ions. The structural unit (B) is a neutralized product of a structural unit derived from the above-mentioned unsaturated carboxylic acid, and is preferably a neutralized product of a structural unit derived from at least one of acrylic acid and methacrylic acid, and more preferably a structural unit of a neutralized methacrylic acid. The structural unit (B) is a structural unit in which the hydrogen ion of the carboxy group in the unsaturated carboxylic acid is substituted with a metal ion. That is, the unsaturated carboxylic acid neutralized product in the structural unit (B) is a metal salt of the unsaturated carboxylic acid. The metal ion in the metal salt is as described above, but is preferably at least one of magnesium and zinc, and particularly preferably magnesium. Therefore, the structural unit (B) preferably contains at least one of magnesium and zinc, and particularly preferably contains magnesium.

[0043] In the ionomer resin, the total content of the structural units (A) and (B) is preferably 10% by mass or more and 25% by mass or less, based on the total amount of the structural units constituting the ionomer resin. When the total content of the structural units (A) and (B) is 10% by mass or more, the transparency, heat resistance, mechanical strength, etc. of the resin composition and interlayer film for laminated glass produced using the masterbatch are likely to be improved. Furthermore, when it is 25% by mass or less, the flexibility, processability, adhesiveness, etc. can be improved. The total content of the structural units (A) and (B) is more preferably 12% by mass or more and 23% by mass or less, and even more preferably 15% by mass or more and 20% by mass or less.

[0044] In the ionomer resin, the content of the structural unit (B) is preferably 4% by mass or more and 18% by mass or less, based on the total amount of the structural units constituting the ionomer resin. When the content of the structural unit (B) is 4% by mass or more, the degree of crosslinking of the ionomer resin increases, and bending rigidity tends to be increased. Furthermore, when the content of the structural unit (B) is 4% by mass or more, transparency and heat resistance tend to be improved. Furthermore, by setting the content of the structural unit (B) to 18% by mass or less, the flexibility, adhesion, mechanical strength, processability, etc. of the interlayer film for laminated glass and the resin composition produced using the masterbatch tend to be improved. The content of the structural unit (B) in the ionomer resin is more preferably from 4% to 17.5% by mass, even more preferably from 6% to 16% by mass, and even more preferably from 10% to 14% by mass.

[0045] The content of the ethylene-derived structural unit (C) is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, and still more preferably 82% by mass or more, based on the total amount of structural units constituting the ionomer resin, from the viewpoint of easily increasing the impact resistance of the ionomer resin. Furthermore, the content of the ethylene-derived structural unit (C) is preferably 90% by mass or less, more preferably 89% by mass or less, even more preferably 88% by mass or less, and still more preferably 85% by mass or less, from the viewpoints of transparency, mechanical strength, and moldability.

[0046] In the ionomer resin, the content of the structural unit (A) is not particularly limited, but is preferably 3% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 10% by mass or less, even more preferably 4% by mass or more and 9% by mass or less, and still more preferably 4% by mass or more and 8% by mass or less, based on the total amount of the structural units constituting the ionomer resin.

[0047] The ionomer resin may be a copolymer of ethylene and a (meth)unsaturated carboxylic acid that has been neutralized with a metal ion, or a copolymer of ethylene, an unsaturated carboxylic acid, and a monomer other than ethylene and an unsaturated carboxylic acid that has been neutralized with a metal ion. Thus, in one embodiment, the ionomer resin may contain, in addition to the structural units (A), (B), and (C), structural units other than the structural units (A), (B), and (C) (hereinafter also referred to as "other structural units").

[0048] Other structural units include structural units (D) derived from alkyl (meth)acrylates. The inclusion of structural unit (D) makes it possible to adjust, for example, the glass transition temperature (Tg) of the ionomer resin. Examples of alkyl (meth)acrylates include alkyl (meth)acrylates having about 1 to 10 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl. The content of the structural unit (D) derived from alkyl (meth)acrylate is preferably 15% by mass or less, more preferably 8% by mass or less, even more preferably 4.5% by mass or less, and even more preferably 2% by mass or less, from the viewpoint of not lowering the glass transition temperature of the thermoplastic resin more than necessary. Furthermore, the content of the structural unit (D) is better as low as possible, from the viewpoint of increasing rigidity at high temperatures without lowering the glass transition temperature, and may be 0% by mass or more, and it is preferable that the ionomer resin does not contain the structural unit (D).

[0049] In addition, isobutyl (meth)acrylate is generally preferably used as the alkyl (meth)acrylate in ionomer resins, but it is preferable that the ionomer resin does not contain structural units derived from isobutyl (meth)acrylate, or if it does, it contains only a small amount. Therefore, the content of structural units derived from isobutyl (meth)acrylate is preferably 15% by mass or less, more preferably 8% by mass or less, even more preferably 4.5% by mass or less, and even more preferably 2% by mass or less. The content of structural units derived from isobutyl (meth)acrylate may be 0% by mass or more, and it is preferable that the ionomer resin does not contain structural units derived from isobutyl (meth)acrylate.

[0050] Furthermore, the ionomer resin may contain, as other structural units, structural units other than the structural units (A), (B), (C), and (D), and may have, for example, structural units derived from vinyl esters such as vinyl acetate and vinyl propionate.

[0051] In the present invention, the degree of neutralization of the ionomer resin is, for example, 30% or more, but from the viewpoint of increasing rigidity, it is preferably more than 40%, more preferably 42% or more, even more preferably 45% or more, and even more preferably 50% or more. Increasing the degree of neutralization of the ionomer resin tends to increase the bending rigidity. Furthermore, in the present invention, by including at least one of magnesium and zinc (particularly magnesium) in the structural unit (B) and increasing the degree of neutralization, it becomes easier to achieve even better rigidity. Furthermore, the degree of neutralization of the ionomer resin is not particularly limited, but from the viewpoint of improving the flexibility, adhesion, mechanical strength, processability, etc. of an interlayer film for laminated glass or a resin composition produced using the masterbatch, the degree of neutralization is preferably 95% or less, more preferably 90% or less, even more preferably 80% or less, and even more preferably 75% or less. The degree of neutralization of the ionomer resin refers to the proportion (%) of carboxyl groups neutralized by metal ions among all carboxyl groups contained in the ionomer resin.

[0052] The degree of neutralization of the ionomer resin can be determined by IR measurement before and after the hydrochloric acid treatment. The specific measurement method is as described in the Examples below. The content of each structural unit in the ionomer resin was determined by mass spectrometry and 1 H-NMR measurement can be performed, and the content of each structural unit in an ethylene-(meth)acrylic acid copolymer can be calculated from the integrated intensity ratio of the hydrogen peaks derived from each monomer and the degree of neutralization. 1 The ratio can be calculated from the integrated intensity ratio of the hydrogen peaks derived from each monomer by H-NMR measurement. The specific details of the measurement method are as described in the Examples below.

[0053] The ionomer resin has a melt mass flow rate (MFR) measured in accordance with JIS K7210:1999 under conditions of 190°C and a load of 2160 g, which, from the viewpoints of processability, mechanical strength, and the like, is, for example, 0.01 g / 10 min or more and 150 g / 10 min or less, preferably 0.01 g / 10 min or more and 50 g / 10 min or less, more preferably 0.1 g / 10 min or more and 30 g / 10 min or less, and even more preferably 0.1 g / 10 min or more and 10 g / 10 min or less.

[0054] The method for producing the ionomer resin is not particularly limited, and the ionomer resin can be produced by a known method. For example, the ionomer resin can be produced by radical copolymerizing each monomer component under high temperature and high pressure to obtain an ethylene-unsaturated carboxylic acid copolymer, and then reacting the copolymer with a metal compound.

[0055] (Ethylene-unsaturated carboxylic acid copolymer) As described above, the thermoplastic resin used in the masterbatch is preferably an ethylene-unsaturated carboxylic acid copolymer. The unsaturated carboxylic acid used in the ethylene-unsaturated carboxylic acid copolymer is as described above for the ionomer resin, and the details are as described above, but acrylic acid and methacrylic acid are preferred. Therefore, the ethylene-unsaturated carboxylic acid copolymer is preferably an ethylene-(meth)acrylic acid copolymer. Ethylene-unsaturated carboxylic acid copolymers typically contain structural units (A) derived from unsaturated carboxylic acid and structural units (C) derived from ethylene, and in the case of ethylene-(meth)acrylic acid copolymers, they contain structural units (structural units (A)) derived from (meth)acrylic acid and structural units (C) derived from ethylene.

[0056] In the ethylene-(meth)acrylic acid copolymer, the content of the structural unit (A) is preferably 10% by mass or more and 25% by mass or less, more preferably 12% by mass or more and 23% by mass or less, and even more preferably 15% by mass or more and 20% by mass or less, based on the total amount of structural units constituting the ethylene-(meth)acrylic acid copolymer. In the ethylene-(meth)acrylic acid copolymer, the content of the structural unit (C) derived from ethylene, based on the total amount of structural units constituting the ethylene-(meth)acrylic acid copolymer, is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, still more preferably 82% by mass or more, and is preferably 90% by mass or less, more preferably 89% by mass or less, even more preferably 88% by mass or less, and still more preferably 85% by mass or less.

[0057] The ethylene-unsaturated carboxylic acid copolymer may be a copolymer of ethylene and a (meth)unsaturated carboxylic acid, or a copolymer of ethylene, an unsaturated carboxylic acid, and a monomer other than ethylene and an unsaturated carboxylic acid. Therefore, in one embodiment, the ethylene-unsaturated carboxylic acid copolymer may contain, in addition to the structural units (A) and (C), structural units other than the structural units (A) and (C) (hereinafter also referred to as "other structural units"). Examples of other structural units include the structural unit (D) derived from an alkyl (meth)acrylate. A detailed description of the alkyl (meth)acrylate and its content is omitted here, as it is the same as that of the ionomer resin. It is preferable that the ethylene-unsaturated carboxylic acid copolymer does not contain the structural unit (D), as with the ionomer resin. Furthermore, the ethylene-unsaturated carboxylic acid copolymer does not contain the structural unit (B) described above.

[0058] The content of the thermoplastic resin in the masterbatch is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, when the entire masterbatch is taken as 100% by mass. By setting the content of the thermoplastic resin to the above lower limit, the additives are properly dispersed in the masterbatch, making segregation less likely to occur. Furthermore, the content of the thermoplastic resin in the masterbatch may be, for example, 99.5% by mass or less, when the entire masterbatch is taken as 100% by mass. However, from the viewpoint of containing a certain amount or more of the additives in the masterbatch, it is preferably 99.1% by mass or less, and more preferably 96% by mass or less.

[0059] [pellet] The masterbatch of the present invention is preferably composed of pellets. The shape of the masterbatch, i.e., the pellets, is not particularly limited, but is preferably any of a sphere, a cylinder, an elliptical cylinder, or a prismatic shape. Here, in the case of a prismatic shape, any polygonal prismatic shape may be used, such as a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism, a heptagonal prism, and an octagonal prism. The shape of the pellets can be adjusted as appropriate by the shape of the die, the cutting method used during pelletizing, and the cooling method, and for example, pellets can be made spherical by cutting using the hot cutting method described below and then water cooling, etc. Furthermore, when using the strand cutting method, it is possible to make the pellets into a columnar shape, and in this case, the cross-sectional shape of the die can be changed to make them into a cylindrical shape or a desired prismatic shape. In this specification, the term "spherical" is not limited to a perfect sphere, but may be a substantially spherical shape with a sphericity of 0.8 or more. Of course, the pellet shape may also be an ellipsoid or oval sphere with a sphericity of less than 0.8. In this specification, the sphericity is expressed as the ratio of the minor axis to the major axis of the pellet, and the closer the ratio is to 1, the closer the pellet is to a sphere. Similarly, the cross section of a cylindrical shape is not limited to a perfect circle, but may be approximately circular with a circularity of 0.8 or more. Furthermore, the cross section of an elliptical cylinder may have a sphericity of less than 0.8. In this specification, circularity is expressed as the ratio of the minor axis to the major axis in the cross section, and the closer the ratio is to 1, the closer it is to a circle.

[0060] Furthermore, the average minor axis of the cross section of the pellets constituting the masterbatch is preferably 1 mm or more and 5 mm or less, and the average major axis is preferably 2 mm or more and 10 mm or less. Having the above sizes of pellets makes them easy to manufacture and improves handleability. Furthermore, the mixability when mixing the masterbatch with other components is also improved. The average minor axis of the above cross section of the pellets is more preferably 2 mm or more and 3 mm or less, and the average major axis is more preferably 3 mm or more and 4 mm or less. Note that when the pellets are spherical, the minor axis and the major axis may be the same, and the cylindrical pellet cross section refers to the surface derived from the cross-sectional shape of the die. The major and minor axes of the pellets can be measured as follows. That is, a projected image of a pellet placed on a horizontal surface is taken in the vertical direction, and the pellet is sandwiched between two parallel lines tangent to the projected image, and the largest distance between the parallel lines is taken as the major axis, and the smallest distance is taken as the minor axis. Note that in this specification, the major and minor axes of granulated products other than pellets can also be measured by a similar measurement method. Furthermore, the major axis and minor axis in the above-mentioned cross section can be determined by sandwiching the cross section between two parallel straight lines, with the major axis being the distance between the parallel lines at their widest point and the minor axis being the distance between the parallel lines at their narrowest point. The average major axis and the average minor axis are values ​​calculated by measuring the major axis and the minor axis of 10 randomly selected pellets and arithmetically averaging them.

[0061] The average length of the pellets is preferably 1 mm or more and 5 mm or less. Having pellets of this size makes them easy to manufacture and easy to handle. It also improves the mixability when mixing the masterbatch with other components. The average length of the pellets is more preferably 2 mm or more and 4 mm or less, and even more preferably 2 mm or more and 3 mm or less. The pellet length is defined as the vertical height of a pellet placed on a horizontal surface. The length of the columnar pellets was measured by placing them with the cross section facing a horizontal plane, and the average length was calculated by measuring the length of 10 randomly selected pellets and arithmetically averaging them.

[0062] <Masterbatch manufacturing method> The method for producing a masterbatch of the present invention includes a step of blending at least one solid additive having a compressibility of 10% or less with a thermoplastic resin to obtain a thermoplastic resin composition (hereinafter, sometimes referred to as a "first resin composition"). The first resin composition may further comprise a liquid additive. The first resin composition may further comprise components (other components) other than the thermoplastic resin, the solid additive, and the liquid additive.

[0063] Here, the solid additive used as a raw material in this production method may have a predetermined degree of compression as described above, but is preferably granulated into a particulate, granular, flake, or other shape. The size of the granulated solid additive is not particularly limited, but it is preferable to use, for example, a solid additive having a major axis of 2 mm to 10 mm, preferably 3 mm to 6 mm, a minor axis of 2 mm to 10 mm, preferably 3 mm to 6 mm, and a length of 2 mm to 10 mm, preferably 3 mm to 6 mm.

[0064] Furthermore, the thermoplastic resin supplied as a raw material is preferably supplied in the form of pellets. The pellets preferably have a minor axis of 1 mm to 5 mm and a major axis of 2 mm to 10 mm, and preferably a minor axis of 2 mm to 4 mm and a major axis of 3 mm to 6 mm, with a length of 1 mm to 5 mm. Supplying the thermoplastic resin in the form of pellets improves workability when producing a masterbatch. Even when the thermoplastic resin is supplied in the form of pellets, the solid additives blended into the masterbatch have a predetermined degree of compression as described above, preventing the solid additives from sliding against the thermoplastic resin pellets and being supplied to the die before the thermoplastic resin, for example, during extrusion molding. Therefore, even when the thermoplastic resin is supplied in the form of pellets, it is possible to uniformly mix the thermoplastic resin with the solid additives, thereby preventing the solid additives from segregating. The details of the thermoplastic resin, solid additives, liquid additives, and other components used in this production method are as described above, and therefore a detailed description thereof will be omitted.

[0065] In this production method, the first resin composition obtained by mixing the components may be appropriately molded into a masterbatch, but it is preferable to form the masterbatch by extrusion molding. By forming the masterbatch by extrusion molding, the first resin composition can be easily molded into pellets that are commonly used as masterbatches. When producing a masterbatch by extrusion molding, it is preferable to use an extruder to mix the components that make up the masterbatch (such as a thermoplastic resin, a solid additive, and a liquid additive), extrude the first resin composition from a die of the extruder, and pelletize the extruded first resin composition by cutting or the like.

[0066] The extruder includes, for example, a cylinder, a raw material supply port provided upstream of the cylinder, and a die provided downstream of the cylinder. A screw is inserted inside the cylinder. The extruder is not particularly limited, but may be a single-screw extruder with one screw provided inside the cylinder, or a twin-screw extruder with two screws arranged in parallel. The raw material supply port is not particularly limited, but may be provided with a hopper, and the components that make up the masterbatch may be introduced into the cylinder from the hopper via the raw material supply port.

[0067] The number of raw material supply ports of an extruder is not particularly limited, and may be one or two. An extruder with one raw material supply port is called a one-feeder, and an extruder with two raw material supply ports is also called a two-feeder. In an extruder with two raw material supply ports, the raw material supply ports may be arranged at different positions in the axial direction of the cylinder. Therefore, in a two-feeder extruder, each component constituting the masterbatch can be fed at a different position in the cylinder. In the following description, in a two-feeder extruder, the upstream raw material supply port may be referred to as the first raw material supply port, and the downstream raw material supply port may be referred to as the second raw material supply port.

[0068] When using a one-feeder extruder, all of the components constituting the masterbatch may be fed into the cylinder from one raw material feed port, whereas when using a two-feeder extruder, some of the components constituting the masterbatch may be fed from the first raw material feed port and the rest from the second raw material feed port. In the two-feeder system, it is preferable to supply the thermoplastic resin and the solid additive from the first raw material supply port and the liquid additive from the second raw material supply port. By adopting such a supply method, the thermoplastic resin and the solid additive supplied from the first raw material supply port are mixed to some extent at the position where the liquid additive is supplied, so that the liquid additive is more easily mixed uniformly in the masterbatch.

[0069] In the extruder, each component introduced through the raw material supply port is melt-kneaded by the screw inside the cylinder and sent downstream. The temperature of the extruder (i.e., the temperature inside the cylinder) may be any temperature that allows the components introduced through the raw material supply port to be sufficiently melt-kneaded, but the maximum temperature of the extruder is preferably about 70 to 160°C higher than the glass transition temperature (Tg) of the thermoplastic resin, and more preferably about 85 to 150°C higher than Tg. If the maximum temperature is within the above temperature range, the components are properly kneaded inside the cylinder without thermal degradation, reducing yellowing and making it easier to obtain a masterbatch in which the components are properly mixed. Specifically, the maximum temperature of the extruder is preferably 150° C. or higher and 220° C. or lower, and more preferably 170° C. or higher and 200° C. or lower. When the thermoplastic resin is, for example, an ionomer resin or an ethylene-(meth)acrylic acid copolymer, a maximum temperature of 150° C. or higher and 220° C. or lower means that the components are properly mixed inside the cylinder without thermal degradation, reducing yellowing and making it easier to obtain a masterbatch in which the components are properly mixed.

[0070] The components mixed inside the cylinder are extruded through a die as a first resin composition to obtain a masterbatch, and the first resin composition extruded through the die may be appropriately cut into pellets, etc. Furthermore, the first resin composition extruded through the die may be appropriately cooled before, after, or while being cut. The first resin composition extruded from the die may be cut by a strand-cutting method in which the extruded first resin composition is extruded in the form of a strand and then cut, or by a hot-cutting method in which the molten and extruded first resin composition is immediately cut. In the strand-cutting method, the strand obtained by extrusion molding may be immersed in water to cool and then removed from the water before being cut, or the strand may be cut in water. In the hot-cutting method, it is preferable to cool the pellets in water after cutting.

[0071] <Uses of Master Bat> The masterbatch of the present invention can be used for various purposes, and may be used in a resin composition requiring the above-mentioned solid additive (hereinafter, sometimes referred to as the "second resin composition"), but is preferably used in an interlayer film for laminated glass. The masterbatch of the present invention may be further mixed with various resin components such as a thermoplastic resin (hereinafter sometimes referred to as a "second thermoplastic resin"), or other components blended as necessary, to form a second resin composition. In this case, the second thermoplastic resin is the same as the thermoplastic resin specifically described above as contained in the masterbatch, and therefore a description thereof will be omitted. When the masterbatch is used for an interlayer film for laminated glass, the second resin composition described above may be formed into a film by extrusion molding, press molding, roll molding, or the like to form the interlayer film for laminated glass. The thickness of the interlayer film for laminated glass is not particularly limited, but is preferably 0.2 mm or more and 4 mm or less, and more preferably 0.4 mm or more and 2.5 mm or less.

[0072] The interlayer film for laminated glass is preferably disposed between two glass members to bond the two glass plates together to form laminated glass. Glass plates may be used as the glass members. The glass plates may be either inorganic or organic glass, with inorganic glass being preferred. Examples of inorganic glass include, but are not limited to, clear glass, clear float glass, float glass plate, tempered glass, colored glass, polished glass plate, patterned glass, wired glass plate, lined glass plate, ultraviolet absorbing glass plate, infrared reflecting glass plate, infrared absorbing glass plate, and green glass. In addition, organic glass is generally called resin glass, and there are no particular limitations. Although not required, examples of the glass include organic glass made of polycarbonate plate, polymethyl methacrylate plate, polyester plate, etc.

[0073] The second thermoplastic resin may be the same type as the thermoplastic resin contained in the masterbatch (hereinafter sometimes referred to as the first thermoplastic resin), or may be a different type. Furthermore, when the first thermoplastic resin is either an ionomer resin or an ethylene-(meth)acrylic acid copolymer, the second thermoplastic resin is preferably an ionomer resin. This configuration allows the second resin composition to be suitably used in an interlayer film for laminated glass. Furthermore, the masterbatch can be easily mixed with the second thermoplastic resin, and the solid additive is not unevenly distributed in the second resin composition, which makes it easier to prevent problems such as deviations in additive concentration from the designed value. Furthermore, when an ionomer resin is used as the first thermoplastic resin, compatibility with the ionomer resin, which is the second thermoplastic resin, is improved, making it easier to improve various performances such as optical properties. On the other hand, when an ethylene-(meth)acrylic acid copolymer is used as the first thermoplastic resin, the viscosity of the second resin composition is also easily reduced. [Example]

[0074] The present invention will be explained in more detail by way of examples, but the present invention is not limited to these examples in any way.

[0075] The methods for measuring various physical properties of the thermoplastic resin and the content of each constituent unit are as follows. [Content of each constituent unit and degree of neutralization] The mass percentage of each structural unit of the ethylene-(meth)acrylic acid copolymer and its ionomer resin is determined by the following hydrochloric acid treatment: 1 The results were determined by H-NMR and IR measurements. [Hydrochloric acid treatment] 500 μL of ethanol and 1 mL of hydrochloric acid were added to 100 mg of a sample that had been freeze-pulverized using JFC-2000 (Japan Analytical Industry Co., Ltd.), and the mixture was stirred for 48 hours at 60°C. After that, the mixture was washed three times with ultrapure water to remove the hydrochloric acid, and then dried by heating.

[0076] [Neutralization level] The degree of neutralization was determined by measuring the IR of the sample before and after the hydrochloric acid treatment. -1 Based on the methylene peak height of 1700 cm -1 The carboxylic acid peak height was calculated using the following formula: In the following formula, the denominator is the peak height at 1700 cm for the sample after hydrochloric acid treatment. -1 Peak height: 1460cm -1 The peak height of the molecule is 1700 cm for the sample before hydrochloric acid treatment. -1 Peak height: 1460cm -1 represents the peak height of

number

[0077] [ 1 H-NMR measurement] The sample after hydrochloric acid treatment was dissolved in a solvent (tetrachloroethane: dimethyl sulfoxide = 5:2) to a concentration of about 1 to 3 mass % to prepare a measurement solution. 1 H-NMR measurements were carried out (apparatus: AVANCE 400 (PRODIGY), spectrometer: AVANCE III HD). Measurement conditions were an accumulation of 8 times and a temperature of 120°C. In the analysis, the integrated value of H derived from the methyl group of methacrylic acid was used as the reference, and this value was set to 3.00. In this case, the total mass% of structural units (A) and (B) and the mass% content of ethylene-derived structural unit (C) were calculated from the integrated intensity ratio of the H peak derived from methylene appearing at 1.15-1.62 ppm. Furthermore, the respective contents of structural units (A) and (B) were calculated from the above-mentioned degree of neutralization.

[0078] [Glass transition temperature (Tg)] The thermoplastic resin was formed into a 0.76 mm thick sheet using a 150°C hot press and cut into a 10 mm long and 5 mm wide piece. The viscoelasticity was measured using a dynamic viscoelasticity measuring device (TA Instruments, product name "ARES-G2") under the following measurement conditions. The sample was placed at 100°C, and viscoelasticity measurements were performed while the temperature was lowered. The peak temperature of the loss tangent tanδ obtained from the results was read. Of the peak temperatures in the temperature range of 0 to 100°C, the peak temperature at which tanδ was maximized was taken as the glass transition temperature. (Measurement conditions) Deformation mode: shear mode, measurement temperature: temperature decrease from 100°C to 0°C, temperature decrease rate: 3°C / min, measurement frequency: 1Hz, strain: 1%, 8mm parallel plate

[0079] <Powder compression degree> The powder compressibility of the solid additive was calculated by measuring the loose bulk density and the packed bulk density and then using the following formula: Powder compressibility (%) = {(packed bulk density - loose bulk density) / packed bulk density} x 100 The loose bulk density was measured by placing the solid additive in a sieve conforming to JIS Z 8801-1:2000, vibrating the sieve, and dropping the sample through a chute to a depth of 100 cm. 3 The density was determined by measuring the density after the top surface of the sample received in a container was leveled off. Since the particle size varies depending on the powder used, the sieve opening was first vibrated at 710 μm, and if the powder did not fall through, the opening was adjusted to a coarser size until the sieve with the opening at which the sample began to fall through was used. The sieve openings used in the examples are shown in Table 1. The compacted bulk density was measured by tapping 180 times at a stroke of 18 mm and a speed of 60 times / min. 3 The density was determined by measuring the density of the solid additive when it was solidified in a container. The powder compressibility was measured using a "Powder Tester (PT-X)" manufactured by Hosokawa Micron Corporation.

[0080] The components used in each of the examples and comparative examples are as follows. (ionomer resin) An ionomer resin made by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. Degree of neutralization = 64%, structural units derived from (meth)acrylic acid (structural unit (A)) = 6.4% by mass, structural units derived from the neutralized product (structural unit (B)) = 11.5% by mass, structural units derived from ethylene (structural unit (C)) = 87.4% by mass, pellet shape (major axis = 4 mm, minor axis = 3 mm, length = 3 mm)

[0081] (Solid additive) [Table 1]

[0082] The additives in Table 1 are as follows: Irganox 1010 and Irganox 1010FF: Product name: pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], manufactured by BASF TINUVIN 928 and TINUVIN 928FF: Product name: 2-[2-hydroxy-3-dimethylbenzylphenyl-5-(1,1,3,3-tetramethylbutyl)]-2H-benzotriazole, manufactured by BASF TINUVIN 326 and TINUVIN 326FF: Product name, (2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole), manufactured by BASF TINUVIN 234: Product name: 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, manufactured by BASF

[0083] (Examples 1 to 4, Comparative Examples 1 to 4) [Preparation of Masterbatch (Mixture (A))] A single-feeder twin-screw extruder was used as the extruder. The ionomer resin and the additives numbered in Table 2 were added to the extruder hopper in the parts by weight shown in Table 2, mixed inside a cylinder adjusted to 180°C, extruded through a die, and the strands were cooled in a water bath and pelletized to obtain a pelletized masterbatch (strand cut method). The resulting pellets were cylindrical, with an average cross-sectional length of 4 mm, an average minor axis of 3 mm, and an average length of 3 mm. In each example and comparative example, 20 kg of masterbatch was produced over 30 minutes.

[0084] The masterbatches obtained in each of the Examples and Comparative Examples were evaluated as follows. <Difference in optical characteristics between the start and end of production> In each Example and Comparative Example, the masterbatch was sampled at the start and end of production, and the masterbatch sampled at the start and end of production was melted again at 180°C and formed into a film having a thickness of 0.76 mm using a press set at 150°C. Laminated glass was produced from the obtained film by the production method described below. The absolute value of the difference in visible light transmittance (%) between the laminated glass (A) made from the masterbatch at the start of production and the laminated glass (B) made from the masterbatch at the end of production was calculated, as well as the absolute value of the difference in haze (%) between the laminated glass (A) and the laminated glass (B). The results are shown in Table 2. The visible light transmittance was measured in accordance with JISR 3106:2019 using a spectrophotometer (Hitachi U-4100 type self-recording spectrophotometer) with a wavelength width of 5 nm, a measurement range of 380 to 780 nm, and a scan speed of 300 nm / min. The haze was measured in accordance with JIS K6714 using a haze meter (Tokyo Denshoku Haze Meter (Model TC-H3DP)).

[0085] (Method for manufacturing laminated glass) The resulting film was cut to a size of 10 cm long x 10 cm wide and sandwiched between two sheets of glass (10 cm long x 10 cm wide x 2 mm thick, float glass plate (manufactured by Sanshiba Glass Co., Ltd.)) to obtain a laminated intermediate. This laminated intermediate was placed in a rubber bag and degassed for 20 minutes at a vacuum of 0.08 MPa. After that, it was transferred to an oven while degassed and held at 90°C for 30 minutes to vacuum press the laminated intermediate, temporarily bonding the laminated intermediate. The temporarily bonded laminated intermediate was then pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes, and the two sheets of glass were bonded with the film to obtain laminated glass.

[0086] <Visual observation> In each of the Examples and Comparative Examples, the master batches were visually observed at the start and end of production to evaluate whether or not there was segregation of the solid additives. The evaluation results are shown in Table 2.

[0087] [Table 2]

[0088] As shown in Table 2, in Examples 1 to 4, the compression ratio of the blended solid additives was 10% or less, so no segregation occurred, the additive concentration in the produced master batch was uniformly stabilized, and there was almost no difference in the optical properties between the start and end of production. In contrast, in Comparative Examples 1 to 4, masterbatches were produced by blending the same types of additives in the same blending amounts as in Examples 1 to 4, but the compressibility of the blended solid additives was greater than 10%. As a result, segregation occurred, the additive concentration in the produced masterbatches could not be stabilized, and the difference in optical properties between the start and end of production was greater than in Examples 1 to 4. In Examples 1 to 4, the amount of additive blended was 1 to 5 parts by mass relative to 100 parts by mass of the ionomer resin. However, segregation did not occur at 1 part by mass, which is a level at which segregation is likely to occur. Therefore, it is believed that segregation would not occur even if the amount of additive blended was further increased (for example, to about 20 parts by mass).

Claims

1. A masterbatch comprising a thermoplastic resin and at least one solid additive having a compressibility of 10% or less.

2. 2. The masterbatch according to claim 1, which is spherical, cylindrical, or prismatic.

3. 3. The masterbatch according to claim 1 or 2, which is in the form of pellets having an average minor axis of 1 mm or more and 5 mm or less.

4. 3. The masterbatch according to claim 1 or 2, which is in the form of pellets having an average major axis of 2 mm or more and 10 mm or less.

5. The masterbatch according to claim 1 or 2, wherein the solid additive contains at least one of an ultraviolet absorber and an antioxidant.

6. The masterbatch according to claim 1 or 2, further comprising a liquid additive.

7. 7. The masterbatch according to claim 6, wherein the content of the liquid additive is 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the thermoplastic resin.

8. 3. The masterbatch according to claim 1, wherein the content of the solid additive is 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the thermoplastic resin.

9. 3. The masterbatch according to claim 1, wherein the total content of the additives contained in the masterbatch is 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the thermoplastic resin.

10. 3. The masterbatch according to claim 1, wherein the thermoplastic resin has a glass transition temperature of 40°C or higher and 75°C or lower.

11. 3. The masterbatch according to claim 1, wherein the thermoplastic resin is an ionomer resin.

12. The masterbatch according to claim 11, wherein the ionomer resin comprises a structural unit (A) derived from (meth)acrylic acid, a structural unit (B) of a neutralized (meth)acrylic acid, and a structural unit (C) derived from ethylene.

13. 13. The masterbatch according to claim 12, wherein the total content of the structural units (A) and (B) in the ionomer resin is 10% by mass or more and 25% by mass or less, based on the total amount of the structural units constituting the ionomer resin.

14. The masterbatch according to claim 12, wherein the ionomer resin has a content of the structural unit (B) of 4% by mass or more and 18% by mass or less, based on the total amount of structural units constituting the ionomer resin.

15. The masterbatch according to claim 12, wherein the structural unit (B) contains any one of sodium, magnesium, and zinc.

16. 3. The masterbatch according to claim 1, wherein the thermoplastic resin is an ethylene / (meth)acrylic acid copolymer.

17. the ethylene-(meth)acrylic acid copolymer contains a structural unit (A) derived from (meth)acrylic acid and a structural unit (C) derived from ethylene, 17. The masterbatch according to claim 16, wherein the content of the structural unit (A) is 10% by mass or more and 25% by mass or less, based on the total amount of structural units constituting the ethylene / (meth)acrylic acid-based copolymer.

18. A method for producing a masterbatch, comprising the step of blending at least one solid additive having a compressibility of 10% or less with a thermoplastic resin to obtain a thermoplastic resin composition.

19. 20. The method for producing the masterbatch according to claim 18, further comprising the step of extruding the thermoplastic resin composition.

20. 20. The method for producing a masterbatch according to claim 19, wherein the extrusion molding is carried out in an extruder, and the maximum temperature in the extruder is 150°C or higher and 220°C or lower.

21. The method for producing a masterbatch according to any one of claims 18 to 20, wherein the thermoplastic resin is supplied in the form of pellets having a minor axis of 1 mm or more and 5 mm or less and a major axis of 2 mm or more and 10 mm or less, and mixed with the solid additive.

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