JP7287004B2 - Aqueous dispersion of copolymer, graft copolymer, thermoplastic resin composition and molded article thereof - Google Patents

Description

The present invention provides a copolymer capable of providing an aqueous dispersion excellent in production stability, shear stability and storage stability, an aqueous dispersion thereof, a graft copolymer using this copolymer, and this graft copolymer The present invention relates to a thermoplastic resin composition containing a polymer and a molded article thereof.

Resins containing diene-based rubber-like polymers and acrylic rubber-like polymers have conventionally been used not only for paints and adhesives, but also for applications such as ABS resins and AAS resins due to their excellent chemical resistance and weather resistance. It is used.

Emulsion polymerization is the most common industrial method for producing diene rubber-like polymers and acrylic rubber-like polymers, and these are produced as aqueous dispersions. In order to use such a diene-based rubber-like polymer or an acrylic rubber-like polymer as a resin, it is necessary to solidify them through, for example, an acid coagulation step. However, since it is difficult to solidify a soft rubber-like substance as it is, for example, a hard component such as styrene or acrylonitrile is graft-copolymerized with an acrylic rubber-like polymer, and then solidified through an acid coagulation step or the like. is performed (Patent Document 1).

However, aqueous dispersions of acrylic rubber-like polymers in particular have poor mechanical stability, and are therefore prone to emulsification failure due to the pressure during pipe transfer of the aqueous dispersion with a pump or the pressure during filtration. may clog the pipes, etc.

As a method for improving the mechanical stability of the aqueous dispersion of the acrylic rubber-like polymer, there is a method of using a large amount of emulsifier. It becomes difficult to handle the body, and when a thermoplastic resin composition using it is continuously molded, gas generated due to the residue derived from the emulsifier contaminates the mold. If the gas generated during molding accumulates in the mold in a greasy state, this deposit migrates to the molded product side and deteriorates the appearance of the molded product. It needs to be removed by cleaning, and continuous molding cannot be performed.

There is also a method of improving the stability of an aqueous dispersion by mixing an acrylic rubber and a diene rubber (Patent Document 2). However, when two or more types of water dispersions are mixed, it is necessary to prepare each water dispersion in advance, which increases the production process. In addition, the addition of the diene rubber greatly impairs the weather resistance, which is a feature of the acrylic rubber.

JP-A-4-170460 JP-A-9-216969

An object of the present invention is to provide an aqueous dispersion of a rubber-like polymer which is excellent in production stability, shear stability and storage stability. The present invention also provides a graft copolymer that can provide a thermoplastic resin molded article having good moldability and continuous moldability and excellent physical properties such as impact resistance, and this graft copolymer. An object of the present invention is to provide a thermoplastic resin composition including coalescence and a molded article thereof.

As a result of extensive studies aimed at solving the above problems, the inventors of the present invention found that a copolymer capable of solving the above problems can be obtained by copolymerizing an ethylenically unsaturated monomer and a specific cross-linking agent. Found it.

The present invention has been achieved based on such findings, and the gist thereof is as follows.

[1] An ethylenically unsaturated monomer (a), a polyol unit (b1) consisting of 10 or more continuous repeating units containing a low molecular weight polyol unit, and two or more ethylenically unsaturated bonds (b2) A copolymer (A) obtained by copolymerizing a hydrophilic cross-linking agent (b) having

[2] The copolymer (A) according to [1], wherein the low-molecular-weight polyol is selected from diols having 1 to 30 carbon atoms.

[3] The copolymer (A) according to [1] or [2], wherein the hydrophilic cross-linking agent (b) has a number average molecular weight of 600 or more.

[4] The copolymer (A) according to any one of [1] to [3], wherein the hydrophilic cross-linking agent (b) has a glycerin skeleton.

[5] An ethylenically unsaturated monomer (a) obtained by copolymerizing an ethylenically unsaturated monomer (a), a hydrophilic cross-linking agent (b), and optionally another cross-linking agent (c) , the ratio of the ethylenically unsaturated monomer (a) in a total of 100 parts by mass of the hydrophilic cross-linking agent (b) and the other cross-linking agent (c) is 1 to 99.9 parts by mass, the hydrophilic cross-linking agent (b ) is 0.01 to 10 parts by mass, and the proportion of the other cross-linking agent (c) is 0 to 30 parts by mass. The copolymer (A) according to any one of [1] to [4]. .

[6] An aqueous dispersion of the copolymer (A) according to any one of [1] to [5].

[7] The aqueous dispersion according to [6], wherein the copolymer (A) in the aqueous dispersion has a volume average particle size of 10 to 1000 nm.

[8] In the copolymer (A) according to any one of [1] to [5], at least one ethylene selected from the group consisting of (meth)acrylic acid esters, aromatic vinyls, and vinyl cyanides A graft copolymer (B) obtained by graft-polymerizing an unsaturated monomer.

[9] 90 to 10% by mass of the ethylenically unsaturated monomer is graft-polymerized with respect to 10 to 90% by mass of the copolymer (A) (provided that the copolymer (A) and the ethylenically unsaturated The total amount of monomers is 100% by mass.), and the proportion of aromatic vinyl in 100% by mass of the ethylenically unsaturated monomer is 50 to 90% by mass and the proportion of vinyl cyanide is 10 to 50% by mass [8 ] The graft copolymer (B) according to .

[10] A thermoplastic resin composition containing the graft copolymer (B) according to [8] or [9].

[11] A molded article obtained by molding the thermoplastic resin composition according to [10].

According to the present invention, it is possible to provide an aqueous dispersion of the copolymer (A) which is excellent in production stability, shear stability and storage stability. It is possible to provide a graft copolymer that can provide a thermoplastic resin molded article having good moldability and excellent physical properties such as impact resistance, a thermoplastic resin composition containing this graft copolymer, and a molded article thereof. can.

FIG. 2 is a schematic diagram showing a mold used for a gas generation/adhesion amount test in Examples.

Embodiments of the present invention will be described in detail below.
In the present specification, the term “unit” refers to a structural portion derived from a monomer compound (monomer) before polymerization. structural part derived from an ester". The content ratio of each monomer unit in the polymer corresponds to the content ratio of the monomer in the monomer mixture used to produce the polymer.
Moreover, "(meth)acrylic acid" means one or both of "acrylic acid" and "methacrylic acid". The same applies to "(meth)acrylate".
Further, the term "molded article" means an article obtained by molding the thermoplastic resin composition.

[Copolymer (A)]
The copolymer (A) of the present invention comprises an ethylenically unsaturated monomer (a), a polyol unit (b1) consisting of 10 or more continuous repeating units containing a low-molecular-weight polyol unit, and two or more ethylenic It is obtained by copolymerizing a hydrophilic cross-linking agent (b) having an unsaturated bond (b2).

<Ethylenically unsaturated monomer (a)>
The ethylenically unsaturated monomer (a) in the present invention is not particularly limited as long as it is a compound having a radically polymerizable carbon-carbon double bond, but the ethylenically unsaturated monomer (a) is a monofunctional compound. is preferably used.

Ethylenically unsaturated monomers (a) include, but are not limited to, (meth)acrylates, conjugated dienes, aromatic vinyls, vinyl cyanides, N-substituted maleimides. , dicarboxylic acid derivatives, fluorinated vinyls, (meth)acrylic acids, and (meth)acrylamides.

More specifically, the ethylenically unsaturated monomer (a) is
(meth)methyl acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, (meth)acrylate Lauryl acrylate, cyclohexyl (meth)acrylate, pentyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxy (meth)acrylate (meth)acrylic acid esters such as propyl;
Conjugated dienes such as butadiene and isoprene;
aromatic vinyls such as styrene, α-methylstyrene, o-, m- or p-methylstyrene, vinylxylene, pt-butylstyrene, ethylstyrene;
Vinyl cyanides such as acrylonitrile and methacrylonitrile;
N-substituted maleimides such as N-cyclohexylmaleimide and N-phenylmaleimide;
Dicarboxylic acid derivatives such as maleic anhydride;
Fluorinated vinyls such as tetrafluoroethylene, perfluoropropylene, and vinylidene fluoride;
(meth)acrylic acid, (meth)acrylic acids such as (meth)acrylic acid salts;
Examples include monofunctional compounds such as (meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, and isopropyl(meth)acrylamide.

As the ethylenically unsaturated monomer (a), one of these may be used, or two or more thereof may be used in combination.

Among these, the copolymer (A) to be obtained preferably has a glass transition temperature of room temperature or lower. Conjugated dienes and (meth)acrylates are particularly preferred.

The ethylenically unsaturated monomer (a) is a total of 100 parts by mass of the ethylenically unsaturated monomer (a), a hydrophilic cross-linking agent (b) described later, and other cross-linking agents (c) used as necessary. It is preferable to use 1 to 99.9 parts by mass, particularly 50 to 99.5 parts by mass, particularly 70 to 99 parts by mass, based on the If the amount of the ethylenically unsaturated monomer (a) used is within the above range, the thermoplastic resin composition obtained by blending the graft copolymer (B) using the obtained copolymer (A) will have impact resistance. It becomes excellent in quality.

<Hydrophilic cross-linking agent (b)>
The hydrophilic cross-linking agent (b) in the present invention comprises a polyol unit (b1) consisting of 10 or more continuous repeating units containing a low molecular weight polyol unit, and two or more ethylenically unsaturated bonds (b2). have.

(Polyol unit (b1))
The polyol unit (b1) is a unit derived from a compound having two or more hydroxyl groups, and in the present invention, the polyol unit (b1) consists of 10 or more consecutive repeating units containing a low molecular weight polyol unit.
The polyol unit (b1) includes 10 or more repeating units (b1-1) derived from a low-molecular-weight polyol, and polyester polyol units (b1-2) and polyamide polyol units (b1-3) having a degree of polymerization of 10 or more. ), polycarbonate polyol units (b1-4), and other polyol units (b1-5).

As the low-molecular-weight polyol constituting the polyol unit (b1), a known diol having preferably 1 to 30 carbon atoms or a molecular weight of 500 or less can be used. Specific examples thereof include the following. be done.
ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3- propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-butyl-3-ethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 3,3′-dimethylolheptane, 1,8-octanediol , 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,4-tetracosanediol, 1,6-tetracosanediol, 1 ,4-hexacosanediol, 1,6-octacosanediol and other aliphatic diols;
1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, tricyclodecanediethanol, cyclopentadienedimethanol, 2,5-norbornanediol, 1,3-adamantanediol, dimer diol, etc. Alicyclic diols;
o-, m-, and p-dihydroxybenzene, 1,2-indanediol, benzene-1,2-dimethanol (alias: phthalyl alcohol), benzene-1,3-dimethanol (alias: isophthalyl alcohol) , benzene-1,4-dimethanol (also known as terephthalyl alcohol), 1,3-bis(2-hydroxyethoxy)benzene, 1,2-bis(2-hydroxyethoxy)benzene, 1,4-bis(2 -hydroxyethoxy)benzene, (3,4-dihydroxyphenyl)methanol (alias: protocatechuyl alcohol), (4-hydroxy-3-methoxyphenyl)methanol (alias: vanillyl alcohol), 2-(4-hydroxy- 3-methoxyphenyl)ethan-1-ol (alias: homovanillyl alcohol), 3-(4-hydroxy-3-methoxyphenyl)prop-2-en-1-ol (alias: coniferyl alcohol), 3- (4-hydroxy-3,5-dimethoxyphenyl)prop-2-en-1-ol (alias: sinapyl alcohol), 1,2-diphenylethane-1,2-diol (alias: hydrobenzoin), hydroquinone, Resorcin, 4-chlororesorcin, 4-methylresorcin, 5-methylbenzene-1,3-diol (alias: orcinol), 2-methylbenzene-1,4-diol (alias: toluhydroquinone), 2,3-dimethyl Benzene-1,4-diol (alias: o-xylohydroquinone), 2,6-dimethylbenzene-1,4-diol (alias: m-xylohydroquinone), 2,5-dimethylbenzene-1,4-diol ( alias: p-xylohydroquinone), 2,3,5-trimethylbenzene-1,4-diol (alias: pseudomohydroquinone), 2-isopropyl-5-methylbenzene-1,4-diol (alias: thymohydroquinone ), 2,3,5,6-tetramethylbenzene-1,4-diol (alias: durohydroquinone), 5-pentylbenzene-1,3-diol (alias: olivetol), 4,4′-methylenediphenol (alias: p,p-bisphenol F), 4,4'-(2-norbornylidene)diphenol, 4,4'-dihydroxymethylbiphenyl, 4,4'-biphenyldiol, 2,3-dihydroxybuphenyl, tetra Nitrobiphenyldiol, 5,5'-dipropyl-biphenyl-2,2'-diol, 3,3'-diaminobiphenyl-4,4'-diol, 5,5'-tetramethylbiphenyl-4,4'-diol , diphenylsilanediol, (E)-4,4′-(hex-3-ene-3,4-diyl)diphenol (also known as diethylstilbestrol), 2,2-bis(4-hydroxyphenyl)sulfone (alias: bisphenol S), 4,4'-isopropylidenephenol, 4,4'-dihydroxydiphenyl ether (alias: 4,4'-oxydiphenol), 2,2-bis(4-hydroxyphenyl)propane (alias : bisphenol A), 1,3-naphthalenediol, 1,5-naphthalenediol, 1,7-naphthalenediol, 1,7-dihydroxymethylnaphthalene, 1,4-dihydroxy-2-naphthalene ammonium sulfonate, 9,9 Aromatic diols such as '-bis(4-hydroxyphenyl)fluorene, 9,9'-bis(3-methyl-4-hydroxyphenyl)fluorene 1,4-dihydro-9,10-anthracenediol:

In the polyol unit (b1), the number of repeating units containing the low-molecular-weight polyol unit is 10 or more, preferably 11 to 200, more preferably 12 to 50. If the number of repeating units is less than 10, the hydrophilicity will be insufficient, and the resulting aqueous dispersion of the copolymer (A) will be inferior in storage stability and shear stability. As the number of repeating units increases, viscosity tends to increase and crystallization tends to occur.

The repeating unit (b1-1) of the low-molecular-weight polyol may contain only one type of low-molecular-weight polyol, or may contain two or more types thereof.

Examples of the polyester polyol unit (b1-2) include units derived from the reaction product of the above low-molecular-weight polyol and low-molecular-weight polycarboxylic acid.

The polyamide polyol unit (b1-3) includes, for example, a unit derived from a reaction product obtained by condensation reaction with a low-molecular-weight polyol at the molecular end of a polyamide formed by a condensation reaction of a low-molecular-weight polycarboxylic acid and a low-molecular-weight polyamine. be done.

Polycarbonate polyol units (b1-4) include, for example, units derived from reaction products of the above-mentioned low molecular weight polyols and carbonate esters.

Other polyol units (b1-5) include, for example, polyurethane units derived from the reaction product of the above low-molecular-weight polyol and low-molecular-weight polyisocyanate.

The polyol unit (b1) may contain only one type of the above polyol units (b1-1) to (b1-5), or may contain two or more types.

Among these, aliphatic diols are preferred as the low-molecular-weight polyol, and ethylene glycol is more preferred, because the more oxygen atoms there are, the higher the affinity of the hydrophilic cross-linking agent (b) with water.
In particular, the polyol unit (b1) is preferably a polyethylene glycol unit (b1-1).
When the hydrophilicity of the hydrophilic cross-linking agent (b) is high, the production stability, storage stability, shear stability of the aqueous dispersion of the obtained copolymer (A), grafting using the copolymer (A) It is preferable because the copolymer (B) is excellent in production stability and powder properties (dispersibility).

(Ethylenically unsaturated bond (b2))
The ethylenically unsaturated bond (b2) of the present invention is not particularly limited, but it should be derived from the aforementioned ethylenically unsaturated monomer (a) and introduced into the hydrophilic cross-linking agent (b). is preferable, and more preferably derived from (meth)acrylic acid esters, dicarboxylic acid derivatives, (meth)acrylic acids, and (meth)acrylamides and is introduced into the hydrophilic cross-linking agent (b), More preferably, it is derived from (meth)acrylic acid esters or (meth)acrylic acids and introduced into the hydrophilic cross-linking agent (b).

The hydrophilic cross-linking agent (b) has two or more, for example, 2 to 100 ethylenically unsaturated bonds (b2). ) is preferably 2 to 20, particularly 2 to 10, from the viewpoint of the molecular chain length between unsaturated bonds.

(Method for producing hydrophilic cross-linking agent (b))
A hydrophilic cross-linking agent (b) having a polyol unit (b1) and an ethylenically unsaturated bond (b2) is a polyol that induces the polyol unit (b1) and an ethylenically unsaturated bond that induces the ethylenically unsaturated bond (b2). It can be produced by reacting saturated monomers. The reaction at that time can be carried out by a known method, for example, a dehydration esterification method in which the terminal hydroxyl group of the polyol is reacted with (meth)acrylic acid to obtain an esterified product while extracting the generated water out of the system, An ester exchange method that obtains an esterified product by extracting the lower alcohol produced by reacting the terminal hydroxyl group with a (meth)acrylic acid ester of a lower alcohol to the outside of the system, and an ethylene system that has a terminal hydroxyl group of polyol and an isocyanate group or an epoxy group. A method of directly reacting with an unsaturated monomer and the like can be mentioned.

(glycerin skeleton)
When the hydrophilic cross-linking agent (b) has a glycerin skeleton, the crystallization of the polyol units (b1) can be suppressed, making it easier to handle and obtaining a more flexible copolymer (A). It is preferable because

In this case, the glycerin skeleton contained in the hydrophilic cross-linking agent (b) is preferably derived from polyglycerin having an average degree of polymerization calculated from the hydroxyl value of preferably 2 to 20, more preferably 4 to 20.
In this specification, the average degree of polymerization (n) calculated from the hydroxyl value is a value calculated by a terminal analysis method, and calculated from the following formulas (1) and (2).
Molecular weight = 74n + 18 (1)
Hydroxyl value = 56110 (n + 2) / molecular weight (2)
The above-mentioned hydroxyl value is a numerical value that is an index of the number of hydroxyl groups contained in a compound. Refers to the number of milligrams of potassium oxide, and the number of milligrams of potassium hydroxide is calculated according to the Japan Oil Chemistry Society compilation, "Japan Oil Chemistry Society Establishment, Standard Oil Analysis Test Method, 2013 Edition".

A glycerin backbone can be introduced into the hydrophilic cross-linking agent (b) by an addition reaction of polyglycerin with a polyol to derive polyol units (b1). The method of this addition reaction is not particularly limited, and for example, the above low-molecular-weight polyol may be addition-polymerized with polyglycerin.

(Number average molecular weight)
The number average molecular weight of the hydrophilic cross-linking agent (b) is preferably 600 or more, more preferably 800 to 30,000, still more preferably 1,000 to 10,000. If the number average molecular weight of the hydrophilic cross-linking agent (b) is within the above range, the aqueous dispersion of the obtained copolymer (A) is excellent in stability, and the graft copolymer using this copolymer (A) The stability of the aqueous dispersion of the polymer (B) and the powder properties are also excellent, and the thermoplastic resin composition containing the graft copolymer (B) is also excellent in physical properties such as impact resistance. It becomes a thing. If the number average molecular weight of the hydrophilic cross-linking agent (b) is too large, it tends to be difficult to handle due to increased viscosity and crystallization.
Here, the number average molecular weight of the hydrophilic cross-linking agent (b) is a polyethylene glycol-equivalent value measured by gel permeation chromatography.

The hydrophilic cross-linking agent (b) may be used alone or in combination of two or more.

(amount to use)
The hydrophilic cross-linking agent (b) is based on a total of 100 parts by mass of the ethylenically unsaturated monomer (a), the hydrophilic cross-linking agent (b), and other cross-linking agents (c) used as necessary. 0.01 to 10 parts by mass, preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass. If the amount of the hydrophilic cross-linking agent (b) used is within the above range, the aqueous dispersion of the obtained copolymer (A) will be excellent in stability, and the graft copolymer using this copolymer (A) will be excellent. The powder properties of coalescence (B) are also excellent.

<Other cross-linking agents (c)>
In the production of the copolymer (A) of the present invention, a cross-linked structure may be introduced into the copolymer (A) by using a cross-linking agent (c) other than the hydrophilic cross-linking agent (b). If it is a crosslinked copolymer (A) in which a crosslinked structure is introduced using another crosslinking agent (c), the crosslinked portion is an ethylenic copolymer (B) described later, which is used in the production of the graft copolymer (B) described later. It also functions as a graft crossing point for grafting with saturated monomers.

Other cross-linking agents (c) include, for example, divinylbenzene, allyl (meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butylene di(meth)acrylate, 1, 4-butylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetradecaethylene glycol di(meth)acrylate, triallyl cyanurate, triallyl isocyanurate, pentaerythritol tetra(meth)acrylate, etc. .
These other cross-linking agents (c) may be used alone or in combination of two or more.

The amount of the other cross-linking agent (c) to be used is not particularly limited. It is usually 0 to 30 parts by mass, preferably 0.01 to 10.0 parts by mass, and more preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass in total. If the amount of the other cross-linking agent (c) is within the above range, the thermoplastic resin composition obtained by blending the graft copolymer (B) using the obtained copolymer (A) will have impact resistance. It becomes a thing excellent in physical properties such as.

[Method for synthesizing copolymer (A)]
As a method for synthesizing the copolymer (A), any method of emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization can be used. Emulsion polymerization is preferred, and mini-emulsion polymerization is more preferred.

<Mini-emulsion polymerization>
The miniemulsion polymerization for producing the copolymer (A) of the present invention is not limited to this, but for example, an ethylenically unsaturated monomer (a) and a hydrophilic crosslinking agent (b), other crosslinking In addition to the agent (c), a hydrophobic substance, and an emulsifier, preferably an initiator, mixing water, applying a shear force to the resulting mixture to prepare a pre-emulsion (mini-emulsion), and this It includes a step of heating the pre-emulsion to the polymerization initiation temperature to polymerize it.

In the process of mini-emulsification, after mixing the polymerization monomer and the emulsifier, for example, by performing a shearing process by ultrasonic irradiation, the monomer is torn off by the shearing force, and the monomer micro oil droplets covered with the emulsifier is formed. After that, by heating to the polymerization initiation temperature of the initiator, the monomer fine oil droplets are polymerized as they are to obtain polymer fine particles.

Any known method can be used to apply a shearing force to form a mini-emulsion. High shear devices capable of forming mini-emulsions include, but are not limited to, emulsifying devices comprising high pressure pumps and interaction chambers, and devices that use ultrasonic energy or radio frequency to form mini-emulsions. Examples of the emulsifying device consisting of a high-pressure pump and an interaction chamber include "pressure homogenizer" manufactured by SPX Corporation APV, "homogenizer" manufactured by Sanwa Engineering Co., Ltd., and "high-pressure homogenizer" manufactured by Sanmaru Kikai Kogyo Co., Ltd. , "Homogenizer" manufactured by Izumi Food Machinery Co., Ltd., and "Microfluidizer" manufactured by Powrex Corporation. Examples of devices for forming a mini-emulsion using ultrasonic energy or high frequency include "Sonic Dismembrator" manufactured by Fisher Scient and "ULTRASONIC HOMOGENIZER" manufactured by Nippon Seiki Seisakusho.

<Water>
From the viewpoint of workability, stability, manufacturability, etc., the amount of the water solvent used when forming the mini-emulsion is such that the solid content concentration of the reaction system after polymerization is about 5 to 58% by mass. It is preferably about 75 to 1900 parts by mass with respect to 100 parts by mass of the mixture. The amount of water used is more preferably about 80 to 1000 parts by mass, more preferably about 90 to 500 parts by mass.

<Hydrophobic substance>
When forming a mini-emulsion, it is preferable to use a hydrophobic substance having a hydrocarbon group selected from alkyl groups having 12 or more carbon atoms, alkenyl groups and cycloalkyl groups. The production stability of the mini-emulsion can be improved by using the hydrophobic substance having this specific hydrophobic hydrocarbon group.

The degree of hydrophobicity of the hydrophobic substance used in the present invention is the logarithm [logP] of the partition coefficient [P] represented by the ratio [c1/c2] of the concentration [c1] for 1-octanol and the concentration [c2] for water. The logarithm [logP] of the partition coefficient [P] of the hydrophobic substance used in the present invention is preferably 6.0 or more, particularly preferably 7.0 or more.

Hydrophobic substances having a logarithm [log P] value of partition coefficient [P] of 6 or more include non-polymerizable hydrophobic compounds such as hydrocarbons having 12 or more carbon atoms, alcohols having 12 or more carbon atoms, hydrophobic Examples of monomers include vinyl esters of alcohols having 14 to 30 carbon atoms, vinyl ethers of alcohols having 14 to 30 carbon atoms, vinyl esters of carboxylic acids having 15 to 30 carbon atoms (preferably 15 to 22 carbon atoms), and 20 to 30 carbon atoms. 40 p-alkylstyrene, hydrophobic chain transfer agents, and the like. These may be used individually by 1 type, and may be used in mixture of 2 or more types.

Specific examples of hydrophobic substances used in the present invention include tetradecane (logP: 6.3), pentadecane (logP: 7.7), hexadecane (logP: 8.3), and heptadecane (logP: 8.8). , octadecane (logP: 9.3), icosane (logP: 10.4), liquid paraffin (logP > 6.0), liquid isoparaffin (logP > 6.0), paraffin wax (logP > 6.0), polyethylene Wax (logP>6.0), olive oil (logP>6.0), cetyl alcohol (logP: 6.7), stearyl alcohol (logP: 8.2), stearyl acrylate (logP: 7.7), methacryl stearyl acid (logP: 9.6) and the like.

By using these hydrophobic substances, it becomes possible to suppress an increase in non-uniformity in particle size due to Ostwald ripening and to synthesize a monodisperse copolymer (A).

The amount of the hydrophobic substance added is 0.1 with respect to a total of 100 parts by mass of the ethylenically unsaturated monomer (a), the hydrophilic cross-linking agent (b), and other cross-linking agents (c) that are used as necessary. 1 to 10 parts by mass is preferable, and 1 to 3 parts by mass is more preferable.

<Emulsifier>
Emulsifiers used in the production of the copolymer (A) of the present invention include carboxylic acid-based emulsifiers exemplified by oleic acid, palmitic acid, stearic acid, alkali metal salts of rosin acid, and alkali metal salts of alkenylsuccinic acid. Emulsifiers, alkyl sulfates, sodium alkylbenzene sulfonate, sodium alkyl sulfosuccinate, anionic emulsifiers selected from sodium polyoxyethylene nonylphenyl ether sulfate, etc. Use known emulsifiers alone or in combination of two or more. can do.

The amount of the emulsifier to be added is 0.01 to 1 part per 100 parts by mass in total of the ethylenically unsaturated monomer (a), the hydrophilic cross-linking agent (b) and other cross-linking agents (c) that are optionally used. 0.0 parts by mass, more preferably 0.05 to 0.5 parts by mass.

<Initiator>
The initiator is a radical polymerization initiator for radically polymerizing the ethylenically unsaturated monomer (a), the hydrophilic cross-linking agent (b), and optionally other cross-linking agent (c). , for example, an azo polymerization initiator, a photopolymerization initiator, an inorganic peroxide, an organic peroxide, a redox initiator obtained by combining an organic peroxide, a transition metal, and a reducing agent. Among these, azo polymerization initiators, inorganic peroxides, organic peroxides, and redox initiators, which can initiate polymerization by heating, are preferred. These may be used alone or in combination of two or more.

Examples of azo polymerization initiators include 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′- Azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl) azo]formamide, 4,4′-azobis(4-cyanovaleric acid), dimethyl 2,2′-azobis(2-methylpropionate), dimethyl 1,1′-azobis(1-cyclohexanecarboxylate) ), 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2′-azobis(N-butyl-2-methylpropionamide), 2,2′-azobis ( N-cyclohexyl-2-methylpropionamide), 2,2′-azobis[2-(2-imidazolin-2-yl)propane], 2,2′-azobis(2,4,4-trimethylpentane), etc. mentioned.

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

Examples of organic peroxides include peroxyester compounds, specific examples of which include α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3, 3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1- Cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy 2-hexylhexanoate, t-butylperoxy 2-hexylhexanoate, t-butylperoxyisobutyrate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-bis(m-toluoylperoxy ) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexylmonocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate, bis(t-butylperoxy)isophthalate, 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane, 1,1 -bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t -butylperoxy)cyclododecane, 2,2-bis(t-butylperoxy)butane, n-butyl-4,4-bis(t-butylperoxy)valerate, 2,2-bis(4,4-di-t -butylperoxycyclohexyl)propane, α,α'-bis(t-butylperoxide)diisopropylbenzene, dicumylperoxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylcumyl Peroxide, di-t-butyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, dilauroyl peroxide, diisononanoyl peroxide, t-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, dimethylbis(t-butylperoxy)-3 -hexyne, bis(t-butylperoxyisopropyl)benzene, bis(t-butylperoxy)trimethylcyclohexane, butyl-bis(t-butylperoxy)valerate, t-butyl 2-ethylhexaneperoxyate, dibenzoyl peroxide, para-menthane Hydroperoxide and t-butyl peroxybenzoate, and the like.

As the redox initiator, a combination of an organic peroxide, ferrous sulfate, a chelating agent and a reducing agent is preferred. For example, one consisting of cumene hydroperoxide, ferrous sulfate, sodium pyrophosphate, and dextrose, or a combination of t-butyl hydroperoxide, sodium formaldehyde sulfoxylate (Rongalite), ferrous sulfate, and disodium ethylenediaminetetraacetate. etc.

Among these, organic peroxides are particularly preferred as initiators.

The amount of the initiator added is usually 5 parts by mass with respect to a total of 100 parts by mass of the ethylenically unsaturated monomer (a), the hydrophilic cross-linking agent (b) and other cross-linking agents (c) that are used as necessary. Below, preferably 3 parts by mass or less, for example, 0.001 to 3 parts by mass.

The initiator may be added before or after forming the mini-emulsion, and the addition method may be batch, divided or continuous.

<Rubber component>
In the production of the copolymer (A) of the present invention, the copolymer (A) made of a composite rubber in which other rubber components are present in the step of preparing the pre-emulsion may be produced to the extent that the desired performance is not impaired. good. In this case, other rubber components include diene rubber such as polybutadiene, polyorganosiloxane, and the like. By polymerizing the ethylenically unsaturated monomer (a) and the hydrophilic cross-linking agent (b) in the presence of these rubber components, for example, a copolymer (A) obtained by compounding a diene rubber such as polybutadiene, etc. is obtained. The composite rubber according to the present invention is not limited to these, and the rubber components to be composited can be used singly or in combination of two or more.

<Additive>
In the production of the copolymer (A) of the present invention, additives may be added in the step of preparing the pre-emulsion, if necessary. In this case, additives include, for example, polystyrene, poly(meth)acrylic acid ester, inorganic substances (silica, zirconia, mica, wollastonite, talc, etc.), fillers (glass fiber, carbon fiber, etc.), lubricants, pigments, etc. (carbon black, titanium oxide, etc.), dyes, heat-resistant agents, antioxidants, weather-resistant agents, release agents, plasticizers, antistatic agents, flame retardants, and the like. These can be blended as long as they do not impair the physical properties of the resulting thermoplastic resin composition or molded article.

<Reaction conditions>
The process of preparing the pre-emulsion is usually carried out at normal temperature (about 10 to 50°C), and the process of mini-emulsion polymerization is carried out at 40 to 100°C for about 30 to 600 minutes.

<Particle size>
The particle size of the copolymer (A) of the present invention is not particularly limited, but is preferably 10 to 1000 nm, more preferably 250 to 600 nm, in terms of volume average particle size. There may be.
The particle size of the copolymer (A) refers to the size of dispersed particles of the copolymer (A) in the aqueous dispersion of the copolymer (A) obtained by the method for producing the copolymer (A) described above. Refers to particle size.

The method for measuring the particle size of the copolymer (A) of the present invention is as described in the Examples section below.

[Aqueous dispersion of copolymer (A)]
The copolymer (A) of the present invention is produced in the form of an aqueous dispersion with excellent production stability by the method for producing the copolymer (A) described above.
The aqueous dispersion (also referred to as "latex") of the copolymer (A) of the present invention has excellent shear stability, so that it does not coagulate during pump transportation or the like, and is excellent in handleability. Moreover, since it is excellent in storage stability, it can be stored stably without separating even if it is stored still in a container.

The copolymer (A) concentration of the aqueous dispersion of the copolymer (A) of the present invention usually corresponds to the solid content concentration of the reaction system in the production of the copolymer (A) of the present invention, preferably 5 ~58% by mass, more preferably 10 to 45% by mass.
Moreover, the particle size of the copolymer (A) in the aqueous dispersion of the copolymer (A) of the present invention is as described above.

[Graft copolymer (B)]
The graft copolymer (B) of the present invention comprises the copolymer (A) of the present invention and at least one ethylenically unsaturated monomer selected from (meth)acrylates, aromatic vinyls, and vinyl cyanides. (hereinafter sometimes referred to as "graft monomer component") is graft-polymerized to form a graft layer.
The graft monomer component may contain vinyl compounds other than (meth)acrylic acid ester, aromatic vinyl, and vinyl cyanide.

The graft ratio of the graft layer of the graft copolymer (B) was calculated by the following method, and the graft ratio was determined by this method also in the examples described later.

<Calculation of graft ratio>
80 mL of acetone is added to 2.5 g of the graft copolymer (B) and the mixture is refluxed in a hot water bath at 65° C. for 3 hours to extract acetone-soluble matter. The remaining acetone-insoluble matter is separated by centrifugation, dried and weighed. From the mass of the acetone-insoluble matter in the obtained graft copolymer (B) and the mass of the copolymer (A) used in the production of the graft copolymer (B), the graft Calculate the rate.

The graft ratio of the graft copolymer (B) of the present invention is preferably 1 to 99%, more preferably 30 to 85%. If the graft ratio of the graft copolymer (B) is within the above range, the stability of the aqueous dispersion of the graft copolymer (B) and the powder characteristics are good, and the impact resistance and molded appearance are good. you can get the goods.

As the (meth)acrylic acid ester to be graft polymerized to the copolymer (A) of the present invention, the (meth)acrylic acid ester of the ethylenically unsaturated monomer (a) used for producing the copolymer (A) of the present invention is One or two or more of those exemplified as the class can be used. Also, the aromatic vinyl and vinyl cyanide are one of those exemplified as the aromatic vinyls and vinyl cyanides of the ethylenically unsaturated monomer (a) used in the production of the copolymer (A) of the present invention. Or 2 or more types can be used.

The graft layer constituting the graft copolymer (B) contains components derived from ethylenically unsaturated monomers other than the aforementioned (meth)acrylic acid ester, aromatic vinyl, and vinyl cyanide. may Other ethylenically unsaturated monomers include (meth)acrylic monomers among those exemplified as the ethylenically unsaturated monomers used as the ethylenically unsaturated monomer (a) in the production of the copolymer (A) of the present invention. One or two or more ethylenically unsaturated monomers other than acid esters, aromatic vinyls, and vinyl cyanides may be used.

The graft copolymer (B ) is preferable because it has excellent thermal stability. In this case, the ratio of aromatic vinyl such as styrene and vinyl cyanide such as acrylonitrile is preferably 50 to 90% by mass of aromatic vinyl and 10 to 50% by mass of vinyl cyanide (however, aromatic vinyl The total amount of vinyl and vinyl cyanide is 100% by mass).

The graft layer of the graft copolymer (B) is obtained by emulsion graft polymerization of 90 to 10% by mass of the graft monomer component with respect to 10 to 90% by mass of the copolymer (A). The appearance of the thermoplastic resin molded article obtained using this graft copolymer (B) is excellent, which is preferable (provided that the total of the copolymer (A) and the graft monomer component is 100% by mass). . More preferably, the proportion is 50 to 80% by weight of the copolymer (A) and 20 to 50% by weight of the graft monomer component. As the ratio of the copolymer (A) increases, the ratio of the graft copolymer (B) in the thermoplastic resin composition described below can be reduced, leading to cost reduction.

As a method of graft polymerization of the graft monomer component to the copolymer (A), the graft monomer component is added to the latex of the copolymer (A) obtained by miniemulsion polymerization, and the A method of polymerization can be mentioned. In the case of multi-stage polymerization, it is preferable to add the graft monomer component to the latex of the copolymer (A) in a divided manner or continuously for polymerization. By such a polymerization method, good polymerization stability can be obtained, and a latex of the graft copolymer (B) having a desired particle size and particle size distribution can be stably obtained. Examples of the polymerization initiator used for this graft polymerization include the same radical polymerization initiators as those used for the miniemulsion polymerization in the method for producing the copolymer (A) of the present invention.

In order to stabilize the latex of the copolymer (A) and control the average particle size of the obtained graft copolymer (B) when the graft monomer component is graft polymerized to the copolymer (A). can be added with an emulsifier. The emulsifier used here is not particularly limited, but includes the same emulsifiers as the emulsifiers used in the mini-emulsion polymerization in the method for producing the copolymer (A) of the present invention, and anionic emulsifiers and nonionic emulsifiers are preferred. . The amount of the emulsifier to be used when the graft monomer component is graft-polymerized to the copolymer (A) is not particularly limited, but is 0.1 to 10 parts per 100 parts by mass of the resulting graft copolymer (B). Parts by mass are preferable, and 0.2 to 5 parts by mass are more preferable.

Although the method for recovering the graft copolymer (B) from the latex of the graft copolymer (B) obtained by emulsion polymerization is not particularly limited, the following methods may be mentioned.
The latex of the graft copolymer (B) is poured into hot water in which a coagulant is dissolved to solidify the graft copolymer (B). Next, the solidified graft copolymer (B) is redispersed in water or hot water to form a slurry, and the emulsifier residue remaining in the graft copolymer (B) is eluted into water and washed. Next, the slurry is dehydrated with a dehydrator or the like, and the resulting solid is dried with a flash dryer or the like to recover the graft copolymer (B) as powder or particles.

The coagulant includes inorganic acids (sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, etc.), metal salts (calcium chloride, calcium acetate, aluminum sulfate, etc.), and the like. A coagulant is appropriately selected according to the type of emulsifier. For example, when only a carboxylate (fatty acid salt, rosin acid soap, etc.) is used as an emulsifier, any coagulant may be used. When using an emulsifier such as sodium alkylbenzenesulfonate which exhibits stable emulsifying power even in an acidic range, an inorganic acid is insufficient and a metal salt must be used.

The volume average particle diameter of the graft copolymer (B) of the present invention produced as described above using the copolymer (A) of the present invention is preferably 20 to 1200 nm, more preferably 300 to 800 nm. be.

The method for measuring the particle size of the graft copolymer (B) of the present invention is as described in Examples below.

[Thermoplastic resin composition]
The thermoplastic resin composition of the present invention contains the above-described graft copolymer (B) of the present invention, and 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 10 to 80 parts by mass, more preferably 15 to 60 parts by mass. Within the above range, the flowability (moldability) and the impact resistance, rigidity and other physical properties of the molded product are well balanced.

The thermoplastic resin composition of the present invention may optionally contain other thermoplastic resins and additives than the graft copolymer (B) of the present invention.

Other thermoplastic resins include, for example, 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, polycarbonate, polyamide, polyethylene terephthalate, polyester such as polybutylene terephthalate, polyphenylene ether-polystyrene composite 1 type or 2 or more types, such as a body, are mentioned. Among these, acrylonitrile-styrene copolymers are preferred from the viewpoint of impact resistance and fluidity.

Examples of additives include coloring agents such as pigments and dyes, fillers (carbon black, silica, titanium oxide, etc.), flame retardants, stabilizers, reinforcing agents, processing aids, heat-resistant agents, anti-oxidation agents, and weather-resistant agents. , release agents, plasticizers, antistatic agents, and the like.
These additives may be added in the step of preparing the pre-emulsion in the production of the copolymer (A) of the present invention, as described above.

The thermoplastic resin composition of the present invention is obtained by mixing and dispersing the graft copolymer (B) and, if necessary, other thermoplastic resins and additives using a V-type blender, a Henschel mixer, or the like. It is produced by melt-kneading the mixture using a kneader such as an extruder, a Banbury mixer, a pressure kneader, or a roll.
The mixing order of each component is not particularly limited as long as all the components are uniformly mixed.

[Molding]
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, rigidity, molding appearance and the like.

Examples of methods 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. mentioned. Among these, the injection molding method and the injection compression molding method are preferable because they are excellent in mass productivity and can obtain molded articles with high dimensional accuracy.

The molded article of the present invention obtained by molding the thermoplastic resin composition of the present invention has excellent mechanical properties such as impact resistance and low-temperature impact resistance, and excellent molded appearance. is suitable for

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

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

In the following, "parts" means "parts by mass" and "%" means "% by mass".

[Measurement of volume average particle size]
The volume average particle diameters of the copolymers (A-1) to (A-7) and the graft copolymers (B-1) to (B-8) produced in Examples and Comparative Examples were obtained by Nikkiso Co., Ltd. It was determined by the dynamic light scattering method using Nanotrac UPA-EX150.

[Measurement of the amount of agglomerates]
Copolymers (A-1) to (A-7) produced in Examples and Comparative Examples and latexes of graft copolymers (B-1) to (B-8) were each filtered through a 100-mesh wire mesh. , the agglomerates remaining on the 100-mesh wire mesh are dried and weighed, respectively, copolymers (A-1) to (A-7), graft copolymers (B-1) to (B-8) The ratio (% by mass) was determined. The smaller the amount of coagulum, the better the production stability of the copolymers (A-1) to (A-7) and the latexes of the graft copolymers (B-1) to (B-8).

[Evaluation of shear stability]
300 g of the latexes of the copolymers (A-1) to (A-7) produced in Examples and Comparative Examples and the latexes of the graft copolymers (B-1) to (B-8) were placed in a 500 mL beaker, The mixture was stirred for 15 minutes with a high-speed homogenizer "HG92" manufactured by SMT Co., Ltd., a shaft "PB-1", and a rotation speed of 15000 rpm. The state of the latex after stirring (whether or not there is coagulation) was visually observed and evaluated according to the following criteria.
(double-circle): It does not cream even if it passes for 15 minutes.
O: Not coagulated even after 15 minutes.
Δ: Solidified within 10 to 15 minutes.
x: Solidified within 10 minutes.
If ⊚ or ◯, solidification does not occur during pump transportation, and it can be judged that the shear stability is good.

[Evaluation of storage stability]
Copolymers (A-1) to (A-7) produced in Examples and Comparative Examples and 30 g of latexes of graft copolymers (B-1) to (B-8) were placed in a 50 mL container with a lid. The state of the latex (presence or absence of precipitation) after standing still for 30 days was visually observed and evaluated according to the following criteria.
A: No sediment even after 30 days.
◯: A precipitate appears in 20 to 30 days.
Δ: A precipitate appears after 10 to 20 days.
x: A deposit appears within 10 days.
If it is ⊚ or ◯, it can be judged that the storage stability is good because it does not separate even if it is left still in the container.

[Evaluation of dispersibility (powder characteristics)]
100 parts of a 1.5% sulfuric acid aqueous solution is heated to 40° C., and latexes of the graft copolymers (B-1) to (B-8) produced in Examples and Comparative Examples are added to the aqueous solution while stirring the aqueous solution. 100 parts of each was gradually added dropwise to solidify, and the temperature was further raised to 95° C. and held for 10 minutes.
The obtained powder was sieved through an 8-mesh (2 μm mesh) wire mesh, and the ratio of the non-passing amount was calculated by the following formula.
Non-passing amount (%) = non-passing amount (g) / (non-passing amount + passing amount) (g) x 100
If the 8-mesh non-passing amount (%) is less than 10%, the graft copolymer (B) is well dispersed in the thermoplastic resin composition.

[Hydrophilic cross-linking agent (b)]
Commercially available hydrophilic cross-linking agents (b-1) to (b-6) described below were used for the production of the copolymers (A-1) to (A-6).
<Hydrophilic cross-linking agent (b) for Examples>
Hydrophilic cross-linking agent (b-1): Shin-Nakamura Chemical Co., Ltd. "A-1000"
Polyethylene glycol #1000 diacrylate
Number of ethylenically unsaturated bonds: 2
Number of continuous repeating units of low molecular weight polyol: 23
Number average molecular weight: 1000
Hydrophilic cross-linking agent (b-2): "SA-TE60" manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.
Polyethylene glycol-modified polyglycerin-based acrylate
Number of ethylenically unsaturated bonds: 6
Number of continuous repeating units of low-molecular-weight polyol: 14
Number average molecular weight: 4000
Average degree of polymerization of polyglycerin (n): 3

<Hydrophilic cross-linking agent (b) for comparative example>
Hydrophilic cross-linking agent (b-3): Shin-Nakamura Chemical Co., Ltd. "A-400"
Polyethylene glycol #400 diacrylate
Number of ethylenically unsaturated bonds: 2
Number of continuous repeating units of low-molecular-weight polyol: 9
Number average molecular weight: 400
Hydrophilic cross-linking agent (b-4): Shin-Nakamura Chemical Co., Ltd. "A-GLY-20E"
Polyethylene glycol-modified polyglycerin-based acrylate
Number of ethylenically unsaturated bonds: 3
Number of continuous repeating units of low-molecular-weight polyol: 6
Number average molecular weight: 1300
Average degree of polymerization of polyglycerin (n): 1
Hydrophilic cross-linking agent (b-5): "SA-TE6" manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.
Polyethylene glycol-modified polyglycerin-based acrylate
Number of ethylenically unsaturated bonds: 6
Number of continuous repeating units of low-molecular-weight polyol: 6
Number average molecular weight: 2000
Average degree of polymerization of polyglycerin (n): 3
Hydrophilic cross-linking agent (b-6): Fujifilm Wako Pure Chemical Industries, Ltd.
Polyethylene glycol #1000
Number of ethylenically unsaturated bonds: 0
Number of continuous repeating units of low molecular weight polyol: 23
Number average molecular weight: 1000

[Production and Evaluation of Copolymer (A)]
<Example I-1: Production of copolymer (A-1)>
A copolymer (A-1) was produced with the following formulation.

[Formulation]
n-Butyl acrylate 97 parts Allyl methacrylate 1 part Hydrophilic cross-linking agent (b-1) 2 parts Liquid paraffin 2 parts Dipotassium alkenyl succinate 0.2 parts Dilauroyl peroxide 0.6 parts Distilled water 400 parts

In a container n-butyl acrylate (Log P = 1.9), liquid paraffin (Log P > 6.0), allyl methacrylate (Log P = 1.5), hydrophilic cross-linking agent (b-1), dilauroyl peroxide , distilled water, and dipotassium alkenyl succinate were charged, and stirred at room temperature for 5 minutes at 9000 rpm using "High Flex Disperser HG92" manufactured by SMT Co., Ltd. to obtain a mixture. The resulting mixture was treated twice at a pressure of 20 MPa and a flow rate of 135 L/hr using a "high-pressure homogenizer H3-1D" manufactured by Sanmaru Kikai Kogyo Co., Ltd. to obtain a pre-emulsion. The volume average particle size of the obtained pre-emulsion was 350 nm.

A reactor equipped with a reagent injection container, a cooling pipe, a jacket heater and a stirrer was charged with the obtained pre-emulsion. and radical polymerization was initiated. The liquid temperature rose to 78°C due to the polymerization of the acrylate component. The temperature was maintained at 75°C for 30 minutes to complete the polymerization of the acrylate component. The time required for production was 70 minutes, and a latex of copolymer (A-1) having a solid content of 18.5% and a volume average particle diameter of 350 nm was obtained. The amount of coagulum in the resulting copolymer (A-1) was 0.01%.

<Example I-2, Comparative Examples I to 5: Production of copolymers (A-2) to (A-7)>
In Example I-2 and Comparative Examples I-1 to I-4, except that the type of hydrophilic cross-linking agent (b) used was changed as shown in Table 1, in the same manner as in Example I-1, Latexes of copolymers (A-2) to (A-6) were respectively obtained.
In Comparative Example I-5, the hydrophilic cross-linking agent (b) was not used, and the blending amounts of n-butyl acrylate and allyl methacrylate were set as shown in Table 1. A latex of polymer (A-7) was obtained.

Table 1 shows the evaluation results of each of the copolymers (A-1) to (A-7).

[Production and Evaluation of Graft Copolymer (B)]
<Example II-1: Production of graft copolymer (B-1)>
A reactor equipped with a reagent injection container, a cooling pipe, a jacket heater, and a stirrer is charged with raw materials according to the following composition. bottom.

[Formulation]
Water (including water in the copolymer (A-1) latex) 230 parts Copolymer (A-1) latex 70 parts (as solid content)
Dipotassium alkenyl succinate 0.5 parts Sodium formaldehyde sulfoxylate 0.3 parts Ferrous sulfate heptahydrate 0.001 parts Disodium ethylenediaminetetraacetate 0.003 parts

Then, the temperature was raised to 80° C. while dropping a mixed solution containing acrylonitrile, styrene and t-butyl hydroperoxide in the following composition over 100 minutes.

[Formulation]
Acrylonitrile 10 parts Styrene 20 parts t-butyl hydroperoxide 0.2 parts

After completion of dropping, the temperature was maintained at 80° C. for 30 minutes and then cooled to obtain a latex of graft copolymer (B-1). The solid content of the graft copolymer (B-1) in the resulting latex was 29.7%, the amount of coagulum was 0.01%, the volume average particle diameter was 400 nm, and the graft ratio was 25%.

Next, 100 parts of a 1.5% sulfuric acid aqueous solution is heated to 80° C., and while stirring the aqueous solution, 100 parts of the graft copolymer (B-1) latex is gradually added dropwise to the aqueous solution to obtain a graft copolymer ( B-1) was solidified, and the temperature was raised to 95° C. and held for 10 minutes.
The solidified product was then dehydrated, washed and dried to obtain a powdery graft copolymer (B-1).

<Example II-2, Comparative Examples II-1 to II-6: Production of graft copolymers (B-2) to (B-8)>
In Example II-2 and Comparative Examples II-1 to II-5, latexes of copolymers (A-2) to (A-7) were used instead of the latex of copolymer (A-1). Graft copolymers (B-2) to (B-7) were obtained in the same manner as in Example II-1 except for the above.
In Comparative Example II-6, after polymerizing in the same manner as for graft copolymer (B-7), 1 part of dipotassium alkenylsuccinate was additionally added to obtain graft copolymer (B-8).

Table 2 shows the evaluation results of the graft copolymers (B-1) to (B-8).

[Production and Evaluation of AN-ST Thermoplastic Resin Composition]
<Examples III-1 to III-6, Comparative Examples III-1 to III-4: Production of thermoplastic resin compositions>
Graft copolymers (B-1) to (B-8) and acrylonitrile (AN)-styrene (ST) copolymer produced by suspension polymerization ("UMG AXS Resin S102N" manufactured by Techno-UMG Co., Ltd.) were mixed using a Henschel mixer at the ratios shown in Table 3, and the mixture was supplied to an extruder heated to 240° C. and kneaded to obtain pellets 1, respectively.
Further, 100 parts of Pellets 1 and 0.8 parts of carbon black were mixed using a Henschel mixer, and the mixture was supplied to an extruder heated to 240° C. and kneaded to obtain Black Pellets 2, respectively.

<Preparation of test piece>
Using the pellet 1 of the thermoplastic resin composition, molding is performed with a 4-ounce injection molding machine (manufactured by Japan Steel Works, Ltd.) under the conditions of a cylinder temperature of 240 ° C., a mold temperature of 60 ° C., and an injection rate of 20 g / sec. Thus, a rod-shaped compact 1 having a length of 80 mm, a width of 10 mm and a thickness of 4 mm was obtained.
Similarly, the black pellets 2 of the thermoplastic resin composition are injection molded under the conditions of a cylinder temperature of 240° C., a mold temperature of 60° C., and an injection rate of 20 g/sec to obtain a plate-like shape having a length of 100 mm, a width of 100 mm, and a thickness of 3 mm. A compact 2 was obtained.

<Evaluation>
(Measurement of Charpy impact value)
In accordance with ISO 179-1: 2013 edition, under the conditions of test temperatures of 23 ° C and -30 ° C, Charpy impact strength (impact direction: edge wise) was measured. A higher Charpy impact value means better impact resistance.

(Measurement of melt volume rate (MVR))
The MVR of pellet 1 was measured under conditions of 220° C.-98 N according to the ISO 1133 standard. MVR is a measure of the moldability of a thermoplastic resin composition.

(Evaluation of color development)
The lightness L* of molded body 2 was measured by the SCE method using a spectrophotometer (“CM-3500d” manufactured by Konica Minolta Optips, Inc.). Let the measured L* be “L* (ma)”. It was determined that the lower the L*, the blacker the color, and the better the color developability.
“Lightness L*” means a lightness value (L*) among color values in the L*a*b* color system adopted in JIS Z8729.
The “SCE method” means a method of measuring color by using a spectrophotometer conforming to JIS Z 8722 and removing specularly reflected light with a light trap.

(Measurement of surface gloss)
Using a "digital variable angle gloss meter UGV-5D" manufactured by Suga Test Instruments Co., Ltd., reflectance (%) of the surface of the molded body 2 at an incident angle of 60 ° and a reflection angle of 60 ° is measured in accordance with JIS K 7105. It was measured. It means that the higher the reflectance, the better the molded appearance.

(Gas generation/adherence test)
Using the pellet 1, as shown in FIG. 1, the injected molten resin flows from the sprue 11 through the runners 12 and 13 in two directions, is injected from the side gates 14 and 15, and joins in the mold to form a weld. Injection molding was performed on the mold 10 forming the surface. At that time, a short shot is taken so that the molten resin 20 is in an unfused state without forming a weld surface at the center part in the mold 10, and a gas pool is formed in the mold 10. 100 shots were injection molded. After injection molding, the fat-like deposit adhering to the portion of the mold 10a where the unfused portion was exposed was measured as the amount of gas adhering. If the gas generated during molding accumulates in the mold in a greasy state, this deposit migrates to the molded product side and deteriorates the appearance of the molded product. It must be removed by cleaning, resulting in poor continuous moldability. The smaller the amount of gas adhering, the better the continuous moldability.

Table 3 shows the results of Examples III-1 to III-2 and Comparative Examples III-1 to III-6.

The results of the above Examples and Comparative Examples have revealed the following.

As shown in Table 1, the copolymers (A-1) and (A-2) of the present invention have a small amount of coagulum and are excellent in latex shear stability and storage stability.
As shown in Table 2, the graft copolymers (B-1) to (B-2) using these copolymers (A-1) and (A-2) have little coagulum and latex. Excellent shear stability, excellent storage stability, and excellent dispersibility (powder properties).
The thermoplastic resin compositions of Examples III-1 and III-2 using the graft copolymers (B-1) and (B-2) had, as shown in Table 3, impact resistance, low-temperature impact resistance, It can be seen that it is excellent in terms of properties, fluidity (moldability), color development, surface gloss (molding appearance), and gas adhesion (continuous moldability).
On the other hand, copolymers (A-3) to (A-6) using hydrophilic cross-linking agents (b-3) to (b-6) outside the scope of the present invention, hydrophilic cross-linking agent (b) A copolymer (A-7) that does not use the It was inferior in any of stability, shear stability, storage stability and dispersibility (powder properties). Furthermore, the thermoplastic resin composition using the graft copolymers (B-3) to (B-8) has excellent impact resistance, low-temperature impact resistance, color development, molding appearance, and gas adhesion (continuous moldability). It was inferior to either.

Since the copolymer (A) of the present invention is excellent in production stability, mass production is easy, and by making the graft copolymer (B) containing a large amount of the copolymer (A), the graft copolymer The content of (B) can be reduced, and cost reduction of the thermoplastic resin composition can be realized.
In addition, the thermoplastic resin composition using the graft copolymer (B) of the present invention is excellent in moldability and continuous moldability, and the molded article thereof has excellent impact resistance, low-temperature impact resistance, color development, and moldability. Appearance is good. The balance of moldability, continuous moldability, impact resistance, low-temperature impact resistance, color developability, and molded appearance is extremely superior to molded articles made of conventional thermoplastic resin compositions. Thermoplastic resin compositions and molded articles thereof are also highly useful as various industrial materials.

10 mold 11 sprue 12, 13 runners 14, 15 side gate 20 molten resin

Claims (10)

an ethylenically unsaturated monomer (a);
A hydrophilic cross-linking agent (b) having a glycerin skeleton, a polyethylene glycol unit (b1) consisting of 10 or more consecutive repeating units containing an ethylene glycol unit, and two or more ethylenically unsaturated bonds (b2).
Aqueous dispersion of copolymer (A) obtained by copolymerizing with. 2. The aqueous dispersion of the copolymer (A) according to claim 1, wherein the hydrophilic cross-linking agent (b) has a number average molecular weight of 600 or more. obtained by copolymerizing an ethylenically unsaturated monomer (a), a hydrophilic cross-linking agent (b), and optionally another cross-linking agent (c) to obtain an ethylenically unsaturated monomer (a), a hydrophilic The ratio of the ethylenically unsaturated monomer (a) in the total 100 parts by mass of the cross-linking agent (b) and the other cross-linking agent (c) is 1 to 99.9 parts by mass, and the ratio of the hydrophilic cross-linking agent (b) is 0.01 to 10 parts by mass, and the proportion of the other cross-linking agent (c) is 0 to 30 parts by mass. The aqueous dispersion according to any one of claims 1 to 3, wherein the copolymer (A) in the aqueous dispersion has a volume average particle size of 10 to 1000 nm. an ethylenically unsaturated monomer (a);
A hydrophilic cross-linking agent (b) having a glycerin skeleton, a polyethylene glycol unit (b1) consisting of 10 or more consecutive repeating units containing an ethylene glycol unit, and two or more ethylenically unsaturated bonds (b2).
At least one ethylenically unsaturated monomer selected from the group consisting of (meth)acrylic acid esters, aromatic vinyls, and vinyl cyanides is graft-polymerized to the copolymer (A) obtained by copolymerizing Graft copolymer (B). 90 to 10% by mass of the ethylenically unsaturated monomer is graft-polymerized with respect to 10 to 90% by mass of the copolymer (A) (the total of the copolymer (A) and the ethylenically unsaturated monomer is 100% by mass.), and the ratio of aromatic vinyl in 100% by mass of the ethylenically unsaturated monomer is 50 to 90% by mass and the ratio of vinyl cyanide is 10 to 50% by mass . A graft copolymer (B) of 7. The graft copolymer (B) according to claim 5 or 6, wherein the hydrophilic cross-linking agent (b) has a number average molecular weight of 600 or more. The copolymer (A) is obtained by copolymerizing an ethylenically unsaturated monomer (a), a hydrophilic cross-linking agent (b), and optionally another cross-linking agent (c), and an ethylenic The proportion of ethylenically unsaturated monomer (a) in a total of 100 parts by mass of unsaturated monomer (a), hydrophilic cross-linking agent (b) and other cross-linking agent (c) is 1 to 99.9 parts by mass, hydrophilic 5 to 7, wherein the copolymer (A) contains 0.01 to 10 parts by mass of the reactive cross-linking agent (b) and 0 to 30 parts by mass of the other cross-linking agent (c). The graft copolymer (B) according to any one of . A thermoplastic resin composition comprising the graft copolymer (B) according to any one of claims 5 to 8 . A molded article obtained by molding the thermoplastic resin composition according to claim 9 .

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