阅读说明：本技术 橡胶质聚合物、接枝共聚物和热塑性树脂组合物 (Rubbery polymer, graft copolymer and thermoplastic resin composition ) 是由 岩永崇 于 2018-06-18 设计创作，主要内容包括：一种橡胶质聚合物(A),其为包含下述式(I)所表示的交联剂(I)单元和(甲基)丙烯酸酯(a)单元的橡胶质聚合物(A),其中,体积平均粒径(X)、频率上限10％体积粒径(Y)和频率下限10％体积粒径(Z)满足特定的关系。一种接枝共聚物(B),其是对该橡胶质聚合物(A)接枝聚合芳香族乙烯基单体和氰化乙烯基单体中的1种以上而成的。含有该接枝共聚物(B)的热塑性树脂组合物及其成型品CH<Sub>2</Sub>＝CR<Sup>1</Sup>-CO-(Q)-COCR<Sup>1</Sup>＝CH<Sub>2</Sub>…(I)。(A rubber polymer (A) comprising a crosslinking agent (I) unit represented by the following formula (I) and a (meth) acrylate (a) unit, wherein the volume average particle diameter (X), the upper frequency limit 10% volume particle diameter (Y), and the lower frequency limit 10% volume particle diameter (Z) satisfy specific relationships. A graft copolymer (B) obtained by graft-polymerizing 1 or more of an aromatic vinyl monomer and a vinyl cyanide monomer to the rubbery polymer (A)In (1). Thermoplastic resin composition containing the graft copolymer (B) and molded article CH thereof 2 ＝CR 1 ‑CO‑(Q)‑COCR 1 ＝CH 2 …(I)。)

1. A rubbery polymer (A) comprising a crosslinking agent unit represented by the following formula (I) and a (meth) acrylate (a) unit, wherein the crosslinking agent represented by the following formula (I) is referred to as a "crosslinking agent (I)" below, and wherein the volume average particle diameter (X) is represented by X, the particle diameter at which the cumulative frequency from the upper limit in the particle diameter distribution curve reaches 10% is represented by Y as the upper frequency limit 10% volume particle diameter (Y), and the particle diameter at which the cumulative frequency from the lower limit in the particle diameter distribution curve reaches 10% is represented by Z as the lower frequency limit 10% volume particle diameter (Z), and the volume average particle diameter (X), the upper frequency limit 10% volume particle diameter (Y), and the lower frequency limit 10% volume particle diameter (Z) satisfy the following (1) or (2),

(1) the volume average particle size (X) is less than 300nm, the upper frequency limit 10% volume particle size (Y) is less than or equal to 1.6X, the lower frequency limit 10% volume particle size (Z) is more than or equal to 0.5X,

(2) the volume average particle diameter (X) is 300-800 nm, the upper frequency limit 10% volume particle diameter (Y) is less than or equal to 1.8X, the lower frequency limit 10% volume particle diameter (Z) is more than or equal to 0.4X,

CH₂＝CR¹-CO(Q)-COCR¹＝CH₂…(I)

in the formula (I), Q represents at least 1 diol residue selected from the group consisting of polyalkylene glycols, polyester glycols, polyurethane glycols, polycarbonate glycols, polybutadiene glycols and hydrogenated polybutadiene glycols having a number average molecular weight of 700 or more,

R¹represents H or CH₃。

2. The rubber-like polymer (A) according to claim 1 which is a polymerization reaction product of a raw material mixture having a gel content of 80 to 100%,

the raw material mixture contains a crosslinking agent (I), a (meth) acrylic ester (a), another vinyl compound used as needed, and a hydrophobic substance, and the proportion of the hydrophobic substance is 0.1 to 10 parts by mass relative to 100 parts by mass of the total of the crosslinking agent (I), the (meth) acrylic ester (a), and the other vinyl compound used as needed.

3. The rubbery polymer (A) according to claim 1 or 2, wherein a storage elastic modulus G 'at 0 ℃ is 2MPa or less, and a loss elastic modulus G' at-80 ℃ is 20MPa or more.

4. A graft copolymer (B) obtained by graft-polymerizing at least 1 vinyl monomer (B) selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers to the rubbery polymer (A) according to any one of claims 1 to 3.

5. A thermoplastic resin composition comprising the graft copolymer (B) of claim 4.

6. A molded article obtained by molding the thermoplastic resin composition according to claim 5.

7. The method for producing the rubber-like polymer (A) according to any one of claims 1 to 3, which comprises a microemulsion step of microemulsifying a mixture comprising the crosslinking agent (I), the (meth) acrylic ester (a), a hydrophobic substance, an emulsifier and water; and a polymerization step of polymerizing the microemulsion thus obtained.

8. A process for producing a graft copolymer (B), characterized by graft-polymerizing at least 1 vinyl monomer (B) selected from an aromatic vinyl monomer and a vinyl cyanide monomer to the rubbery polymer (A) obtained by the production process according to claim 7 to obtain the graft copolymer (B).

9. A method for producing a thermoplastic resin composition, using the graft copolymer (B) obtained by the production method according to claim 8.

10. A method for producing a molded article, wherein the thermoplastic resin composition obtained by the production method according to claim 9 is molded.

Technical Field

The present invention relates to a rubber polymer which can give a graft copolymer having good moldability and can provide a molded article having an excellent balance among impact resistance, low-temperature impact resistance, mechanical strength, rigidity, appearance and weather resistance. The present invention relates to a graft copolymer using the rubbery polymer, a thermoplastic resin composition, and a molded article thereof.

Background

Thermoplastic resins are used in many fields including automobile fields, house and building material fields, electric and electronic equipment fields, and OA equipment such as printers, among which ABS resins, ASA resins, and the like obtained by blending a styrene-acrylonitrile copolymer resin, α -methylstyrene-acrylonitrile copolymer resin, styrene-acrylonitrile-phenylmaleimide copolymer resin, and the like with a graft copolymer obtained by graft-polymerizing a monomer for imparting compatibility with the copolymer resin to a rubbery polymer are widely used because of their excellent impact resistance and flowability.

ASA resins using a component such as an alkyl (meth) acrylate rubber as a saturated rubber as a rubbery polymer are excellent in weather resistance. However, ASA resin has poor impact resistance as compared with ABS resin.

For the purpose of improving the impact resistance of ASA resins, methods of increasing the amount of an acrylate-based rubbery polymer and combining rubber particles having different particle size distributions have been proposed (patent documents 1 to 3).

However, if the amount of the rubber-like polymer is increased, moldability and rigidity of the molded article are deteriorated. When rubber particles having different particle size distributions are combined, moldability and impact resistance at low temperatures are insufficient.

In order to improve the impact resistance of ASA resins, methods using a polymeric crosslinking agent have been proposed (patent documents 4 and 5).

In patent document 4, a polymer crosslinking agent is introduced into a rubber phase. In patent document 1, polymerization is performed in 2 stages or more, and a polymer crosslinking agent is used after the 2 nd stage. This is because, when the polymer crosslinking agent is used in stage 1, the polymer crosslinking agent cannot transfer from oil droplets to micelles due to its large molecular weight, and the amount of coagulum increases. When the polymerization is divided into 2 stages or more, small particles are formed without seeding, and therefore, the resulting rubber polymer has a wide particle size distribution, and the impact resistance-improving effect is insufficient, and the moldability is also poor.

In patent document 5, as in patent document 4, a monomer containing a polymer crosslinking agent is dropped onto seed particles containing no polymer crosslinking agent, and the seed particles are synthesized. Therefore, small particles are also produced without seeding, and thus the impact resistance improving effect is insufficient and moldability is also poor.

Patent document 1: japanese laid-open patent publication No. 59-232138

Patent document 2: japanese laid-open patent publication No. H04-225051

Patent document 3: japanese laid-open patent publication No. H08-134312

Patent document 4: japanese patent laid-open No. 2012 and 144714

Patent document 5: japanese patent No. 5905115

Disclosure of Invention

The purpose of the present invention is to provide a rubber polymer which can give a graft copolymer having good moldability and can provide an excellent molded article having a good balance among impact resistance, low-temperature impact resistance, mechanical strength, rigidity, appearance and weather resistance. Further, the present invention aims to provide a graft copolymer using the rubbery polymer, a thermoplastic resin composition, and a molded article thereof.

The present inventors have found that the above object can be achieved by using a rubbery polymer having a narrow particle size distribution and a crosslinking agent having a specific molecular weight, and have completed the present invention.

That is, the gist of the present invention is as follows.

[1] A rubber polymer (A) comprising a crosslinking agent (hereinafter referred to as "crosslinking agent (I)") unit represented by the following formula (I) and a (meth) acrylic ester (a) unit, wherein when a volume average particle diameter (X) is represented by X, a particle diameter at which a cumulative frequency value from an upper limit in a particle diameter distribution curve reaches 10% is represented by Y as an upper frequency limit 10% volume particle diameter (Y), and a particle diameter at which a cumulative frequency value from a lower limit in the particle diameter distribution curve reaches 10% is represented by Z as a lower frequency limit 10% volume particle diameter (Z), the volume average particle diameter (X), the upper frequency limit 10% volume particle diameter (Y), and the lower frequency limit 10% volume particle diameter (Z) satisfy the following formula (1) or (2),

(1) the volume average particle size (X) is less than 300nm, the upper frequency limit 10% volume particle size (Y) is less than or equal to 1.6X, the lower frequency limit 10% volume particle size (Z) is more than or equal to 0.5X,

(2) the volume average particle diameter (X) is 300-800 nm, the upper frequency limit 10% volume particle diameter (Y) is less than or equal to 1.8X, the lower frequency limit 10% volume particle diameter (Z) is more than or equal to 0.4X,

CH₂＝CR¹-CO-(Q)-COCR¹＝CH₂…(I)

in the formula (I), Q represents at least 1 diol residue selected from the group consisting of polyalkylene glycols, polyester glycols, polyurethane glycols, polycarbonate glycols, polybutadiene glycols and hydrogenated polybutadiene glycols having a number average molecular weight of 700 or more, and R¹Represents H or CH₃。

[2] The rubber polymer (A) according to [1], which is a polymerization reaction product of a raw material mixture having a gel content of 80 to 100%,

the raw material mixture contains a crosslinking agent (I), a (meth) acrylic ester (a), another vinyl compound used as needed, and a hydrophobic substance, and the proportion of the hydrophobic substance is 0.1 to 10 parts by mass relative to 100 parts by mass of the total of the crosslinking agent (I), the (meth) acrylic ester (a), and the other vinyl compound used as needed.

[3] The rubbery polymer (A) according to [1] or [2], wherein a storage elastic modulus G 'at 0 ℃ is 2MPa or less, and a loss elastic modulus G' at-80 ℃ is 20MPa or more.

[4] A graft copolymer (B) obtained by graft-polymerizing at least 1 vinyl monomer (B) selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers to the rubbery polymer (A) according to any one of [1] to [3 ].

[5] A thermoplastic resin composition comprising the graft copolymer (B) according to [4 ].

[6] A molded article obtained by molding the thermoplastic resin composition according to [5 ].

[7] [1] A method for producing the rubber polymer (A) according to any one of [1] to [3], which comprises a microemulsion step of microemulsifying a mixture comprising the crosslinking agent (I), the (meth) acrylic acid ester (a), a hydrophobic substance, an emulsifier and water; and a polymerization step of polymerizing the microemulsion thus obtained.

[8] A process for producing a graft copolymer (B), characterized by graft-polymerizing at least 1 vinyl monomer (B) selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers to the rubbery polymer (A) obtained by the process according to [7 ].

[9] A method for producing a thermoplastic resin composition, which uses the graft copolymer (B) obtained by the production method according to [8 ].

[10] A method for producing a molded article, wherein the thermoplastic resin composition obtained by the production method according to [9] is molded.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the rubber polymer (A) and the graft copolymer (B) of the present invention, there can be provided an excellent thermoplastic composition having good moldability and a good balance among impact resistance, low-temperature impact resistance, mechanical strength, rigidity, appearance and weather resistance, and a molded article thereof.

Drawings

FIG. 1 is a graph showing the results of measuring the storage elastic modulus G' of the rubber-like polymers (A-9), (A-13) and (A-14) produced in examples and comparative examples.

FIG. 2 is a graph showing the measurement results of the loss elastic modulus G' of the rubber-like polymers (A-9), (A-13) and (A-14) produced in examples and comparative examples.

Detailed Description

The embodiments of the present invention are described in detail below.

In the present specification, "unit" means a structural part derived from a monomer compound (monomer) before polymerization. For example, "(meth) acrylate unit" means "a moiety derived from a (meth) acrylate". The content ratio of each monomer unit in the polymer corresponds to the content ratio of the monomer in the monomer mixture used for producing the polymer.

"(meth) acrylic acid" means one or both of "acrylic acid" and "methacrylic acid". The same applies to "(meth) acrylate".

The "molded article" refers to a product obtained by molding a thermoplastic resin composition.

The "residue" means a structural moiety derived from a compound used in the production of a reaction product such as a polymer (in the present invention, a crosslinking agent (I)) and incorporated into the reaction product. For example, the residue Q described later corresponds to a residue obtained by removing 1 hydrogen atom from each of 2 hydroxyl groups of a polyalkylene glycol, a polyester glycol, a polyurethane glycol, a polycarbonate glycol, a polybutadiene glycol, a hydrogenated polybutadiene glycol, or a polymer of 1 or more of these.

[ rubbery Polymer (A) ]

The rubber polymer (A) of the present invention will be explained.

The rubber polymer (a) of the present invention is a polymer containing a unit of a crosslinking agent represented by the following formula (I) (hereinafter referred to as "crosslinking agent (I)") and a unit of a (meth) acrylate (a), and has a specific particle size distribution as described later.

CH₂＝CR¹-CO-(Q)-COCR¹＝CH₂…(I)

In the formula (I), Q represents at least 1 diol having a number average molecular weight of 700 or more selected from the group consisting of polyalkylene glycols, polyester glycols, polyurethane glycols, polycarbonate glycols, polybutadiene glycols and hydrogenated polybutadiene glycolsAnd (c) a residue. R¹Represents H or CH₃。

The rubber polymer (a) of the present invention is produced by microemulsion polymerization comprising the following steps: a step of preparing a pre-emulsion from a raw material mixture containing the crosslinking agent (I), (meth) acrylate (a) and a hydrophobic substance, preferably further containing an emulsifier, more preferably a raw material mixture containing the crosslinking agent (I), (meth) acrylate (a), a hydrophobic substance, an initiator, an emulsifier and water; and a step of polymerizing the obtained pre-emulsion.

Hereinafter, a method for producing the rubbery polymer (a) of the present invention by microemulsion polymerization in which a pre-emulsion (microemulsion) is prepared from a raw material mixture containing the crosslinking agent (I), (meth) acrylate (a), a hydrophobic substance, an initiator, an emulsifier, and water, and the obtained pre-emulsion is polymerized will be described. The raw material mixture may contain, in addition to the crosslinking agent (I) and the (meth) acrylic acid ester (a), other vinyl compounds copolymerizable with these used, as required.

In the microemulsion polymerization, firstly, a strong shearing force is applied by an ultrasonic oscillator or the like, thereby preparing monomer oil droplets of about 100 to 1000 nm. At this time, the emulsifier molecules are preferentially adsorbed to the surface of the monomer oil droplets, and free emulsifiers or micelles hardly exist in the aqueous medium any more. Therefore, in an ideal microemulsion polymerization, the monomer radicals do not partition between the aqueous phase and the oil phase, and the monomer oil droplets polymerize as the core of the particles. As a result, the formed monomer oil droplets are directly converted into polymer particles, and homogeneous polymer nanoparticles can be obtained.

In contrast, in the case of polymer particles prepared by ordinary emulsion polymerization, since monomers are transferred from monomer oil droplets to micelles to react with each other, when a plurality of monomers having different hydrophobicity are contained, the ease of transfer to micelles is different, and a homogeneous polymer cannot be formed.

< microemulsion polymerization >

The miniemulsion polymerization for producing the rubber polymer (a) of the present invention is not limited thereto, and may include, for example, a step of mixing the crosslinking agent (I), (meth) acrylate (a), a hydrophobic substance, and an emulsifier, and preferably further mixing an initiator and water; a step of preparing a pre-emulsion by applying a shearing force to the obtained mixture; and a step of heating the pre-emulsion to a polymerization initiation temperature to polymerize the pre-emulsion. In the microemulsion step, monomers for polymerization are mixed with an emulsifier, and then subjected to a shearing step by ultrasonic irradiation, for example, to pull apart the monomers by the shearing force to form monomer fine oil droplets coated with the emulsifier. Then, the monomer micro oil drops are directly polymerized by heating to the polymerization initiation temperature of the initiator, so as to obtain the polymer particles. The method of applying the shearing force for forming the pre-emulsion may use any known method.

The high shear device capable of forming a pre-emulsion is not limited to this, and examples thereof include an emulsifying device comprising a high-pressure pump and an oscillating reaction chamber, and a device for forming a micro-emulsion by using ultrasonic energy or high frequency. Examples of the emulsifying apparatus comprising a high-pressure pump and an oscillation reaction chamber include a "pressure homogenizer" manufactured by SPX Corporation APV, and a "Microfluidizer" manufactured by POWREX Corporation. Examples of the device for forming a microemulsion by using ULTRASONIC energy or high frequency include "Sonic dismermator" manufactured by Fisher scientific and "ULTRASONIC HOMOGENIZER" manufactured by japan seiko corporation.

The amount of the water solvent used in the preparation of the pre-emulsion is preferably set to about 100 to 500 parts by mass per 100 parts by mass of the mixture other than water so that the solid content concentration of the reaction system after polymerization is about 5 to 50% by mass from the viewpoints of workability, stability, manufacturability and the like.

< crosslinking agent (I) >)

In the production of the rubber polymer (a) of the present invention, a crosslinking agent (I) represented by the following formula (I) is used together with the (meth) acrylate (a) in order to introduce a crosslinked structure into the poly (meth) acrylate (a) component obtained from the (meth) acrylate (a) described later.

CH₂＝CR¹-CO-(Q)-COCR¹＝CH₂…(I)

In the formula (I), Q represents at least 1 diol residue having a number average molecular weight of 700 or more selected from the group consisting of polyalkylene glycol, polyester glycol, polyurethane glycol, polycarbonate glycol, polybutadiene glycol and hydrogenated polybutadiene glycol. R¹Represents H or CH₃。

2R in the formula (I)¹May be the same or different.

Hereinafter, Q in formula (I) is sometimes referred to as "diol residue Q". The diol compound constituting the diol residue Q in the crosslinking agent (I) used as a raw material for producing the crosslinking agent (I) may be referred to as a "Q source".

The structure of the diol residue Q contained in the crosslinking agent (I) may be either a repeat of a single structural unit or a repeat of 2 or more structural units. When the structure of Q is a repetition of 2 or more kinds of structural units, the arrangement of the structural units may be either random, block or alternating of the structural units.

The synthesis method of the Q source is not particularly limited. Generally, polyalkylene glycols are produced by polycondensation of glycols or ring-opening polymerization of cyclic ethers using an acid catalyst. The polyester diol is produced by an esterification reaction between a diol and an acid component such as a dibasic acid or an acid anhydride thereof. Polyurethane diols are made by the reaction of a diol with a diisocyanate. Polycarbonate diols are produced by the reaction of a diol with a dialkyl carbonate. Polybutadiene diol, hydrogenated polybutadiene diol, is produced by the reaction of polybutadiene, hydrogenated polybutadiene and ethylene oxide.

As the Q source, a polyalkylene glycol is particularly preferable, and polytetramethylene glycol is more preferable.

The Q source has a number average molecular weight (Mn) of 700 or more, preferably 1500 to 10000, more preferably 2000 to 7000. When the number average molecular weight (Mn) of the Q source is less than 700, the impact resistance of the thermoplastic resin composition containing the graft copolymer (B) using the rubber polymer (a) of the present invention obtained by using the crosslinking agent (I) is deteriorated. The number average molecular weight (Mn) of the Q source is preferably not more than the upper limit because the impact resistance of the thermoplastic resin composition is still lowered when it is too large. For the same reason, the number average molecular weight (Mn) of the crosslinking agent (I) is preferably 800 or more, particularly preferably 1600 to 10200, and particularly preferably 2100 to 7200.

The number average molecular weights (Mn) of the Q source and the crosslinking agent (I) were measured by the methods described in the following examples. For commercial products, catalog values may be employed.

The method for producing the crosslinking agent (I) is not particularly limited. As a method for producing the crosslinking agent (I), the following method can be used: a method (dehydration reaction) in which a (meth) acrylic acid ester precursor is produced by reacting a Q source with (meth) acrylic acid in the presence of an acid catalyst, and water produced as a by-product is removed from the system; or a method in which the Q source is reacted with a lower (meth) acrylate to produce a (meth) acrylate precursor, and then a lower alcohol produced as a by-product is removed (transesterification); and the like.

As the crosslinking agent (I), commercially available products can be used. Specific examples of the crosslinking agent (I) suitable in the present invention include "NK ESTER 23G" (polyethylene glycol dimethacrylate, Mn: 1012 derived from Q), "NK ESTER A-1000" (polyethylene glycol diacrylate, Mn: 1012 derived from Q); "BRENMER 40 PDC-1700" (random copolymer dimethacrylate of polyethylene glycol and polypropylene glycol, Mn: 1704 from Q source) manufactured by Nichiyan oil Co., Ltd; "UH-100 DA (polycarbonate diol diacrylate, Mn: 1000 derived from Q)" and "UH-100 DM (polycarbonate diol dimethacrylate, Mn: 1000 derived from Q)" manufactured by Udo Kyoho; "ARONIX M-1200" (urethane glycol diacrylate, Mn: 4900 from Q source) manufactured by Toyo Synthesis Co., Ltd.; "BAC-45" (polybutadiene glycol diacrylate, Mn: 9900 of Q source) "manufactured by Osaka organic chemical industries, Ltd.

The crosslinking agent (I) may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

The crosslinking agent (I) is preferably used so that the content of the crosslinking agent (I) in the total of the crosslinking agent (I), the (meth) acrylate (a) described later, and other vinyl compounds described later, which are used as needed, is 0.1 to 20% by mass, particularly 0.5 to 10% by mass, and particularly 1 to 5% by mass. When the amount of the crosslinking agent (I) is within the above range, the thermoplastic resin composition obtained by blending the graft copolymer (B) using the obtained rubbery polymer (A) is excellent in impact resistance.

< (meth) acrylic ester (a) >

The (meth) acrylate (a) constituting the rubber polymer (A) of the present invention is preferably a (meth) acrylate having 1 to 11 carbon atoms, which may or may not have a substituent. Examples thereof include acrylic esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, benzyl acrylate, and 2-ethylhexyl acrylate; methacrylic acid esters such as butyl methacrylate, hexyl methacrylate and 2-ethylhexyl methacrylate. Among these (meth) acrylic esters (a), n-butyl (meth) acrylate is preferable, and n-butyl acrylate is particularly preferable, because of the improvement in impact resistance of molded articles obtained from the thermoplastic resin composition. The (meth) acrylic acid ester (a) may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The (meth) acrylate (a) is preferably used so that the content of the (meth) acrylate (a) in the total of the crosslinking agent (I), the (meth) acrylate (a) and, if necessary, another vinyl compound described later is 10 to 99.9% by mass, particularly 50 to 99.5% by mass, and particularly 70 to 99% by mass. When the amount of the (meth) acrylic acid ester (a) is within the above range, a thermoplastic resin composition obtained by blending the graft copolymer (B) using the obtained rubbery polymer (a) is excellent in impact resistance and weather resistance.

< other vinyl Compound >

Examples of the other vinyl compound to be used as needed include aromatic vinyl compounds such as styrene, α -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinylxylene, p-tert-butylstyrene and ethylstyrene, vinyl cyanides such as acrylonitrile and methacrylonitrile, maleimides such as N-cyclohexylmaleimide and N-phenylmaleimide, maleic anhydride, alkylene glycol di (meth) acrylates such as ethylene glycol diacrylate, 1, 3-butylene glycol diacrylate, 1, 4-butylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, 1, 3-butylene glycol dimethacrylate, polyvinyl benzenes such as divinylbenzene and trivinylbenzene, triallyl isocyanurate, triallyl cyanurate, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, diallyl ammonium chloride and allyl compounds such as allyl (meth) acrylate, and 1 or more of these other vinyl compounds can be used alone or in combination with 2 or more of these other vinyl compounds.

When another vinyl compound is used, the amount of the other vinyl compound used is not particularly limited, but it is preferably used in such a manner that the ratio of the other vinyl compound to the total of the crosslinking agent (I), the (meth) acrylate (a) and the other vinyl compound is 0 to 90% by mass, particularly 0.1 to 50% by mass, and particularly 0.3 to 30% by mass.

< hydrophobic substance >

In the production of the rubber polymer (a) of the present invention, it is preferable to use a hydrophobic substance at a predetermined ratio. When a hydrophobic substance is added at the time of forming a pre-emulsion, the production stability of the micro-emulsion polymerization tends to be further improved, and the rubber polymer (a) suitable for the present invention can be produced.

Examples of the hydrophobic substance include hydrocarbons having 10 or more carbon atoms, alcohols having 10 or more carbon atoms, hydrophobic polymers having a mass average molecular weight (Mw) of less than 10000, hydrophobic monomers such as vinyl esters of alcohols having 10 to 30 carbon atoms, vinyl ethers of alcohols having 12 to 30 carbon atoms, alkyl (meth) acrylates having 12 to 30 carbon atoms, vinyl carboxylates having 10 to 30 carbon atoms (preferably 10 to 22 carbon atoms), para-alkylstyrene, hydrophobic chain transfer agents, and hydrophobic peroxides. These hydrophobic substances may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

More specifically, examples of the hydrophobic substance include hexadecane, octadecane, eicosane, liquid paraffin, liquid isoparaffin, paraffin, polyethylene wax, olive oil, cetyl alcohol, stearyl acrylate, lauryl acrylate, stearyl acrylate, lauryl methacrylate, stearyl methacrylate, polystyrene having a number average molecular weight (Mn) of 500 to 10000, poly (meth) acrylate, and the like.

In the present invention, the amount of the hydrophobic substance is preferably 0.1 to 10 parts by mass, more preferably 1 to 3 parts by mass, based on 100 parts by mass of the total of the crosslinking agent (I), the (meth) acrylate (a) and, if necessary, another vinyl compound. When the amount of the hydrophobic substance used is within the above range, the amount of gas generated during molding of the thermoplastic resin composition containing the graft copolymer (B) using the obtained rubbery polymer (a) is small, and the molded article obtained is excellent in impact resistance and weather resistance.

< emulsifier >

As the emulsifier used in the production of the rubber polymer (a) of the present invention, 2 or more of the following known emulsifiers can be used alone or in combination: carboxylic acid-based emulsifiers exemplified by oleic acid, palmitic acid, stearic acid, alkali metal salts of abietic acid, alkali metal salts of alkenylsuccinic acid, and the like; anionic emulsifiers selected from alkyl sulfates, sodium alkylbenzenesulfonates, sodium alkylsulfosuccinates, sodium polyoxyethylene nonylphenyl ether sulfates, and the like; and the like.

The amount of the emulsifier added is preferably 0.01 to 1.0 part by mass, more preferably 0.05 to 0.5 part by mass, based on 100 parts by mass of the total of the crosslinking agent (I), the (meth) acrylate (a) and other vinyl compounds used as needed.

< initiator >

The initiator is a radical initiator for radical polymerization of the crosslinking agent (I), the (meth) acrylate (a) and, if necessary, another vinyl compound. Examples of the initiator include an azo polymerization initiator, a photopolymerization initiator, an inorganic peroxide, an organic peroxide, and a redox initiator in which an organic peroxide is combined with a transition metal and a reducing agent. Among these, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox initiators capable of initiating polymerization by heating are preferable. These initiators may be used alone in 1 kind, or may be used in combination with 2 or more kinds.

Examples of the azo initiator include 2,2 ' -azobis (4-methoxy-2, 4-dimethylvaleronitrile), 2 ' -azobis (2, 4-dimethylvaleronitrile), 2 ' -azobisisobutyronitrile, 2 ' -azobis (2-methylbutyronitrile), 1 ' -azobis (cyclohexane-1-carbonitrile), 1- [ (1-cyano-1-methylethyl) azo ] formamide, 4 ' -azobis (4-cyanopentanoic acid), dimethyl 2,2 ' -azobis (2-methylpropionate), dimethyl 1,1 ' -azobis (1-cyclohexanecarboxylate), 2 ' -azobis [ 2-methyl-N- (2-hydroxyethyl) propionamide ], and mixtures thereof, 2,2 '-azobis (N-butyl-2-methylpropionamide), 2' -azobis (N-cyclohexyl-2-methylpropionamide), 2 '-azobis [2- (2-imidazol-2-yl) propane ], 2' -azobis (2,4, 4-trimethylpentane), and the like.

Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, ammonium persulfate, and hydrogen peroxide.

Specific examples thereof include α' -bis (neodecanoylperoxy) diisopropylbenzene, cumylphenyl peroxyneodecanoate, 1,3, 3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, tert-hexyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, 1,3, 3-tetramethylbutyl peroxy2-ethylhexanoate, 2, 5-dimethyl-2, 5-bis (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethyl peroxy2-ethylhexanoate, tert-hexyl peroxy2-hexylhexanoate, tert-butyl peroxyisobutyrate, tert-hexyl peroxyisopropylmonocarboxylate, tert-butylperoxymaleic acid, tert-butyl peroxy3, 5, 5-trimethylhexanoate, tert-butyl peroxylaurate, tert-butyl 2, 5-dimethyl-2, 5-bis (m-toluoylperoxy) hexane, tert-butylperoxy monopropyl peroxymonopropyl peroxymonocarboxylate, tert-butyl peroxymonopropyl peroxymonocarboxylate, and tert-butyl peroxy2, 5-dimethyl-2, 5-bis (m-toluoylperoxy) hexaneT-butyl 2-ethylhexyl monocarboxylic acid oxide, t-hexyl peroxybenzoate, 2, 5-dimethyl-2, 5-bis (benzoylperoxy) hexane, t-butyl peroxyacetate, t-butyl peroxytoluoylbenzoate, t-butyl peroxybenzoate, bis (t-butylperoxy) isophthalate, 1-bis (t-butylperoxy) -3,3, 5-trimethylcyclohexane, 1-bis (t-hexylperoxy) cyclohexane, 1-bis (t-butylperoxy) -3,3, 5-trimethylcyclohexane, 1-bis (t-butylperoxy) cyclohexane, 1-bis (t-butylperoxy) cyclododecane, 2-bis (t-butylperoxy) butane, n-butyl 4, 4-bis (t-butylperoxy) valerate, 2-bis (4, 4-di-t-butylperoxycyclohexyl) propane, α' -bis (t-butylperoxy) diisopropylbenzene, diisopropylphenyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) propylbenzene, di (t-butylperoxy) benzene, di-butylperoxy) cyclohexane, di (t-butylperoxy) hydroperoxide, di-butylperoxy) propylbenzene, di (t-butylperoxy) benzene, di-butyl benzene, di-tert-butyl benzene, di-butyl hydroperoxide, di-butyl benzene, di (t-butyl hydroperoxide, di-tert-butyl benzene di-butylAlkanes and t-butyl peroxybenzoate, and the like.

As the redox initiator, a redox initiator in which an organic peroxide, ferrous sulfate, a chelating agent, and a reducing agent are combined is preferable. Examples thereof include redox initiators comprising cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate and dextrose; or a redox initiator comprising a combination of t-butyl hydroperoxide, sodium formaldehyde sulfoxylate (Rongalite), ferrous sulfate and disodium ethylenediaminetetraacetate.

Among these, organic peroxides are particularly preferable as the initiator.

The amount of the initiator added is usually 5 parts by mass or less, preferably 3 parts by mass or less, for example, 0.001 to 3 parts by mass, based on 100 parts by mass of the total of the crosslinking agent (I), the (meth) acrylate (a) and other vinyl compounds used as needed.

The initiator may be added before or after the pre-emulsion is formed. The method of adding the initiator may be any one of a one-time method, a batch method and a continuous method.

< rubber component >

In the production of the rubber polymer (a) of the present invention, the rubber polymer (a) composed of a composite rubber containing other rubber components can be produced without impairing the desired performance in the step of preparing the pre-emulsion. In this case, examples of the other rubber component include diene rubber such as polybutadiene, polyorganosiloxane, and the like. By polymerizing the crosslinking agent (I) and the (meth) acrylate (a) in the presence of these rubber components, a rubbery polymer (a) composed of a diene/(meth) acrylate composite rubber or a polyorganosiloxane/(meth) acrylate composite rubber compounded with a (meth) acrylate rubber such as butyl acrylate rubber can be obtained.

The composite rubber of the present invention is not limited thereto. The compounded rubber component may be used alone in 1 kind or in combination of 2 or more kinds.

< reaction conditions >

The pre-emulsion is usually prepared at normal temperature (about 10-50 ℃). The microemulsion polymerization process is carried out at 40-100 ℃ for about 30-600 minutes.

< particle diameter >

The particle diameter of the rubber polymer (a) of the present invention satisfies the following (1) or (2) when the volume average particle diameter (X) is represented by X, the particle diameter when the frequency cumulative value from the upper limit in the particle diameter distribution curve is 10% is represented by Y as the frequency upper limit 10% volume particle diameter (Y), and the particle diameter when the frequency cumulative value from the lower limit in the particle diameter distribution curve is 10% is represented by Z as the frequency lower limit 10% volume particle diameter (Z). When the particle diameter of the rubber polymer (a) satisfies the following (1) or (2), a molded article obtained from a thermoplastic resin composition containing a graft copolymer (B) using the rubber polymer (a) has good impact resistance and molded appearance.

(1) The volume average particle size (X) is less than or equal to 300nm, the upper frequency limit of 10 percent of the volume particle size (Y) is less than or equal to 1.6X, and the lower frequency limit of 10 percent of the volume particle size (Z) is more than or equal to 0.5X.

(2) The volume average particle diameter (X) is 300-1000 nm, the upper frequency limit 10% volume particle diameter (Y) is less than or equal to 1.8X, and the lower frequency limit 10% volume particle diameter (Z) is greater than or equal to 0.4X.

The particle size distribution of the rubber-like polymer (A) of the present invention is more preferably such that the upper frequency limit 10% volume particle size (Y) is not more than 1.6X and the lower frequency limit 10% volume particle size (Z) is not less than 0.5X.

The particle diameter of the rubber polymer (A) in the present invention is preferably 150 to 800nm, more preferably 200 to 600nm, and further preferably 250 to 500nm in terms of the volume average particle diameter (X). When the volume average particle diameter (X) is within the above range, coagulum at the time of polymerization is small, and the impact resistance of the thermoplastic resin composition containing the graft copolymer (B) using the rubber polymer (A) is further improved.

The volume average particle diameter (X) and the particle diameter distribution of the rubber polymer (a) of the present invention are measured by the methods described in the following examples.

< gel content >

The gel content of the rubber polymer (a) of the present invention is preferably 80% or more, particularly preferably 85% or more, and particularly preferably 90 to 100%. The gel content of the rubber polymer (a) was determined as follows.

The latex of the rubbery polymer (A) was coagulated and dried to obtain a polymer, and about 1g (W) of the polymer was precisely weighed₀) This was immersed in about 50g of acetone at a temperature of 23 ℃ for 48 hours to swell the polymer, and then the acetone was removed by decantation. Here, the swollen polymer (W) was precisely weighed_s) Then, the mixture was dried at 80 ℃ under reduced pressure for 24 hours to evaporate and remove acetone absorbed in the polymer, and the acetone was precisely weighed again (W)_d). The gel content was calculated by the following formula.

Gel content (%) ═ W_d/W₀×100

W_dWeight of polymer after drying, W₀Is the weight of the polymer prior to immersion in acetone.

In the case of the rubber polymer (A) having a gel content of 80% or more, a thermoplastic resin composition containing the graft copolymer (B) using the rubber polymer (A) is excellent in impact resistance.

< degree of swelling with acetone >

The rubber polymer (A) of the present invention has an acetone swelling degree preferably in the range of 500 to 1200%, more preferably 600 to 1000%, and further preferably 700 to 900%. The acetone swelling degree of the rubber polymer (a) was determined as follows.

The swelling degree was calculated by the following formula in the same manner as in the measurement of the gel content.

Degree of swelling (%) - (W)_s-W_d)/W_d×100

W_sWeight of swollen polymer, W_dIs the weight of the polymer after drying.

When the degree of acetone swelling is less than the lower limit of the rubber polymer (a), a thermoplastic resin composition containing a graft copolymer (B) using the rubber polymer (a) has poor impact resistance. When the acetone swelling degree is higher than the upper limit, the rubber polymer (a) tends to have poor molding appearance.

< dynamic viscoelasticity >

The rubber polymer (A) of the present invention preferably has a storage elastic modulus G 'at 0 ℃ of 2MPa or less and a loss elastic modulus G' at-80 ℃ of 20MPa or more.

When the storage elastic modulus G' and the loss elastic modulus G ″ are within the above ranges, the impact resistance of the thermoplastic resin composition containing the graft copolymer (B) using the rubber polymer (a) tends to be further improved.

The lower limit of the storage elastic modulus G' at 0 ℃ of the rubber-like polymer (A) of the present invention is usually 0.1MPa or more, and more preferably 0.5 to 1.5MPa, as long as it has a rubbery flat region. The upper limit of the loss elastic modulus G' at-80 ℃ is the maximum value of the rubber polymer (A), and is usually 70MPa or less, more preferably 20 to 60 MPa.

The dynamic viscoelasticity of the rubbery polymer (a) of the present invention is measured by the method described in the section of examples described below.

[ graft copolymer (B) ]

The graft copolymer (B) of the present invention is obtained by graft-polymerizing at least 1 vinyl monomer (B) selected from the group consisting of aromatic vinyl monomers and vinyl cyanide monomers to the rubbery polymer (a) of the present invention produced as described above. The graft copolymer (B) of the present invention is obtained by forming a graft layer comprising a polymerization reaction product of the vinyl monomer (B) on the rubbery polymer (A) of the present invention.

The graft layer constituting the graft copolymer (B) of the present invention is a layer in which a part or all of the vinyl monomer (B) is chemically and/or physically bonded to the rubbery polymer (A).

As the aromatic vinyl monomer and the vinyl cyanide monomer graft-polymerized with the rubber polymer (a) of the present invention, 1 or 2 or more species of the aromatic vinyl monomer and the vinyl cyanide monomer respectively exemplified as other vinyl compounds used as necessary in the production of the rubber polymer (a) of the present invention can be used.

The graft ratio of the graft layer of the graft copolymer (B) was calculated by the following method.

< calculation of graft ratio >

80mL of acetone was added to 2.5g of the graft copolymer (B), and the mixture was refluxed in a hot water bath at 65 ℃ for 3 hours to extract an acetone-soluble component. The residual acetone-insoluble component was separated by centrifugation, and the mass after drying was measured to calculate the mass ratio of the acetone-insoluble component in the graft copolymer (B). The graft ratio was calculated from the mass ratio of acetone-insoluble matter in the obtained graft copolymer (B) using the following formula.

[ number 1]

The graft ratio of the graft copolymer (B) of the present invention is preferably 10 to 90%, and particularly preferably 30 to 85%. When the graft ratio of the graft copolymer (B) is within the above range, a molded article having good impact resistance and molded appearance can be obtained by using the graft copolymer (B).

The graft layer constituting the graft copolymer (B) may contain other vinyl monomers besides the aromatic vinyl monomer and the vinyl cyanide monomer. Examples of the other vinyl monomer include 1 or 2 or more of vinyl compounds other than aromatic vinyl monomers and vinyl cyanide monomers among compounds exemplified as the (meth) acrylic acid ester (a) and other vinyl compounds used as necessary in the production of the rubber polymer (a) of the present invention.

When a mixture of an aromatic vinyl monomer (preferably styrene) and a vinyl cyanide monomer (preferably acrylonitrile) is used as the vinyl monomer (B) forming the graft layer, the resulting graft copolymer (B) is preferable because it is excellent in thermal stability. In this case, the ratio of the aromatic vinyl monomer such as styrene to the vinyl cyanide monomer such as acrylonitrile is preferably 50 to 90% by mass of the aromatic vinyl monomer and 10 to 50% by mass of the vinyl cyanide monomer (the total of the aromatic vinyl monomer and the vinyl cyanide monomer is 100% by mass).

When the graft layer of the graft copolymer (B) is obtained by emulsion graft polymerization of 90 to 10 mass% of the vinyl monomer (B) to 10 to 90 mass% of the rubber polymer (a), the molded article obtained by using the graft copolymer (B) is excellent in appearance, and is preferable (the total of the rubber polymer (a) and the vinyl monomer (B) is 100 mass%). The proportion is more preferably 30 to 70% by mass of the rubber polymer (A) and 70 to 30% by mass of the vinyl monomer (b).

The method of graft-polymerizing the vinyl monomer (b) to the rubber polymer (a) includes a method of adding the vinyl monomer (b) to a latex of the rubber polymer (a) obtained by microemulsion polymerization and polymerizing the mixture in 1 or more steps. In the case of carrying out the polymerization in multiple stages, it is preferable to carry out the polymerization by adding the vinyl monomer (b) in portions or continuously in the presence of the rubber latex of the rubber polymer (a). By such a polymerization method, good polymerization stability can be obtained, and a latex having a desired particle diameter and particle diameter distribution can be stably obtained. The polymerization initiator used in the graft polymerization may be the same as that used in the miniemulsion polymerization for producing the rubber polymer (a) of the present invention.

When the vinyl monomer (B) is polymerized with the rubber polymer (A), an emulsifier may be added to stabilize the latex of the rubber polymer (A) and to control the average particle diameter of the resulting graft copolymer (B). The emulsifier used herein is not particularly limited, and the same emulsifiers as those used in the miniemulsion polymerization for producing the rubber polymer (a) of the present invention are exemplified, and anionic emulsifiers and nonionic emulsifiers are preferable. The amount of the emulsifier used in graft-polymerizing the vinyl monomer (B) to the rubber polymer (a) is not particularly limited, but is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, based on 100 parts by mass of the graft copolymer (B) to be obtained.

The method for recovering the graft copolymer (B) from the latex of the graft copolymer (B) obtained by emulsion polymerization is not particularly limited, and the following methods can be mentioned.

The latex of the graft copolymer (B) is put into hot water in which a coagulant is dissolved, and the graft copolymer (B) is cured. Subsequently, the cured graft copolymer (B) is redispersed in water or warm water to prepare a slurry, and the emulsifier residue remaining in the graft copolymer (B) is dissolved in water and washed. Next, the slurry is dewatered by a dehydrator or the like, and the obtained solid is dried by a pneumatic dryer or the like, whereby the graft copolymer (B) is recovered as powder or particles.

Examples of the coagulant include inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, and the like), metal salts (calcium chloride, calcium acetate, aluminum sulfate, and the like), and the like. The coagulant may be appropriately selected depending on the kind of the emulsifier. For example, in the case of using only a carboxylate (fatty acid salt, rosin acid soap, etc.) as an emulsifier, any coagulant may be used. When an emulsifier, such as sodium alkylbenzenesulfonate, which exhibits a stable emulsifying power even in an acidic region, is used as the emulsifier, the inorganic acid is insufficient, and it is necessary to use a metal salt.

The particle diameter of the graft copolymer (B) of the present invention produced as described above using the rubber-like polymer (A) of the present invention is usually less than 1000nm in terms of volume average particle diameter. The volume average particle diameter of the graft copolymer (B) of the present invention is measured by the method described in the section of examples described later.

[ thermoplastic resin composition ]

The thermoplastic resin composition of the present invention contains the above-mentioned graft copolymer (B) of the present invention. The thermoplastic resin composition of the present invention is usually obtained by mixing the graft copolymer (B) of the present invention with another thermoplastic resin. The content of the graft copolymer (B) in 100 parts by mass of the thermoplastic resin composition of the present invention is preferably 20 to 60 parts by mass. When the content of the graft copolymer (B) in the thermoplastic resin composition is less than 20 parts by mass, the rubber content tends to be small, and the impact resistance of the resulting molded article tends to be low. When the content of the graft copolymer (B) in the thermoplastic resin composition exceeds 60 parts by mass, the flowability (moldability) and the rigidity tend to be deteriorated.

The content of the graft copolymer (B) in 100 parts by mass of the thermoplastic resin composition of the present invention is more preferably 30 to 40 parts by mass in consideration of the balance between the fluidity and the impact resistance, rigidity and other physical properties of the molded article.

The thermoplastic resin composition of the present invention may contain other thermoplastic resins or additives as required.

Examples of the other thermoplastic resin include 1 or 2 or more of polyvinyl chloride, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-styrene-methyl methacrylate copolymer, styrene-acrylonitrile-N-phenylmaleimide copolymer, α -methylstyrene-acrylonitrile copolymer, polymethyl methacrylate, methyl methacrylate-styrene copolymer, methyl methacrylate-N-phenylmaleimide copolymer, polyesters such as polycarbonate, polyamide, polyethylene terephthalate and polybutylene terephthalate, polyphenylene ether-polystyrene composite, and the like, and among these, acrylonitrile-styrene copolymer is preferable from the viewpoint of impact resistance and fluidity.

Examples of the additives include colorants such as pigments and dyes, fillers (carbon black, silica, titanium oxide, and the like), flame retardants, stabilizers, reinforcing agents, processing aids, heat-resistant agents, antioxidants, weather-resistant agents, mold release agents, plasticizers, and antistatic agents.

The thermoplastic resin composition of the present invention is produced as follows: the graft copolymer (B) and, if necessary, other thermoplastic resins and additives are mixed and dispersed by a V-type blender, Henschel mixer or the like, and the resulting mixture is melt-kneaded by a kneader such as an extruder, Banbury mixer, pressure kneader or roll.

The mixing order of the components is not particularly limited as long as all the components are uniformly mixed.

[ molded article ]

The molded article of the present invention is obtained by molding the thermoplastic resin composition of the present invention, and is excellent in impact resistance, low-temperature impact resistance, mechanical strength, rigidity, appearance and weather resistance.

Examples of the method for molding the thermoplastic resin composition of the present invention include injection molding, injection compression molding, extrusion, blow molding, vacuum molding, air-pressure molding, calender molding, and inflation molding. Among these, injection molding and injection compression molding are preferable because of excellent mass productivity and the ability to obtain a molded product with high dimensional accuracy.

The molded article of the present invention obtained by molding the thermoplastic resin composition of the present invention is excellent in impact resistance, low-temperature impact resistance, mechanical strength, rigidity, appearance and weather resistance, and therefore is suitably used for vehicle interior and exterior parts, OA equipment, building materials and the like.

Examples of industrial applications of the molded article of the present invention obtained by molding the thermoplastic resin composition of the present invention include vehicle parts, particularly various exterior and interior parts used without coating, building material parts such as wall materials and window frames, household appliance parts such as tableware, toys, sweeper housings, television housings and air conditioner housings, interior parts, ship parts, and communication equipment housings.