JP3186422B2 - Plastisol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to plastisols ,
More specifically, the present invention relates to a plastisol which has excellent fluidity and storage stability and which gives a tough film or molded article by heat treatment at an appropriate temperature.

[0002]

2. Description of the Related Art A plastisol is a liquid or paste-like mixture obtained by dispersing polymer fine particles in a liquid plasticizer and further dispersing other fillers and the like, and is useful as a molding material. . That is, the plastisol is a molding material which, when heat-treated at an appropriate temperature, causes the polymer fine particles to be compatible with the plasticizer and solidified to give a film or molded product as a gelled product.

Conventionally, such plastisols include:
A material obtained by dispersing polyvinyl chloride in a plasticizer has been known for a long time, and is particularly advantageously used for forming a protective coating film for automobiles and the like. In such a polyvinyl chloride plastisol, during storage at room temperature, the polyvinyl chloride fine particles are dispersed without being plasticized by a plasticizer for a long period of time, and the viscosity at room temperature also increases with time. It has an extremely small amount, and has an excellent property that polyvinyl chloride fine particles and a plasticizer are compatible and solidified only after the plastisol is heated to an appropriate temperature.

[0004] However, polyvinyl chloride has problems such as generation of harmful hydrogen chloride gas during combustion, and difficulty in recycling and using it for resource saving. From the viewpoint of protection, a plastisol of another resin instead of polyvinyl chloride plastisol has been strongly demanded.

Therefore, in plastisols, various polymers composed of halogen-free vinyl monomers have been studied as alternatives to the above polyvinyl chlorides. Coalescence also has various problems depending on the degree of compatibility with the plasticizer. That is, for example, when the polymer is dispersed in a plasticizer, it is immediately compatible and solidified at room temperature, so it is inferior in storage stability, it is liquid at room temperature, but its viscosity increases with time, Poor fluidity, at room temperature, keeps a stable liquid, but after heat treatment, when returned to room temperature, there is a problem that the plasticizer oozes out of the surface of the generated solid, poor compatibility, etc. Further, the coating formed by the heat treatment, when the compatibility of the polymer and the plasticizer is good, the tensile strength is extremely low, on the contrary, when the compatibility is poor, the coating does not stretch, There is also a problem that they become brittle and lack practicality. Because of these various problems, a plastisol of another resin, which replaces polyvinyl chloride plastisol, has not been put to practical use.

For example, JP-A-51-71344 proposes a plastisol in which an alkyl methacrylate or a copolymer of the same with another monomer is combined with various plasticizers. However, because the compatibility of the polymer with the plasticizer and the fluidity and storage stability of the plastisol have conflicting properties, among the proposed plastisols, for example, the compatibility with the polymer of the plasticizer is good,
In addition, a plastisol that gives a gelled product having excellent flexibility by heat treatment has a large increase in viscosity over time at room temperature, and has a problem in storage stability. On the other hand, plastisols having insufficient compatibility of the polymer with the plasticizer have good storage stability at room temperature, but are difficult to be put to practical use because the gelled product obtained by heat-treating them is hard and brittle. It is.

Japanese Patent Application Laid-Open No. 54-117553 proposes a plastisol in which polymethyl methacrylate coated with a polycarboxylate and a copolymer thereof are dispersed in a plasticizer. Such plastisols also have the same significant problems as described above and do not replace vinyl chloride plastisols.

JP-A-53-144950 discloses a core having good compatibility with a plasticizer and a shell which is incompatible with the plasticizer and has a glass transition temperature of 50 ° C. or more. A core-shell polymer consisting of is disclosed. However, in such a core-shell polymer, the boundary between the core layer and the shell layer is not clear from the affinity between the polymers due to the monomer composition used for each layer. Have a problem. That is, first, when the shell layer is thin, the compatibility of the polymer surface with the plasticizer is not constant, and the plastisol obtained by dispersing such a polymer in the plasticizer has poor storage stability, In order to obtain storage stability, if the shell layer is thickened, it is incompatible with the plasticizer, and the polymer fraction of the polymer in the shell layer having a high glass transition temperature is increased. The resulting coating or molded article has no elongation and is brittle.

[0009]

As a substitute for polyvinyl chloride plastisol, the present inventors have proposed a novel core-shell polymer in order to solve the above-mentioned problems in the previously proposed plastisols. As a result of diligent research from the viewpoint of development and utilization of the polymer, it has been found that when a core-shell polymer having a predetermined structure is used as a polymer component in a plastisol, excellent results can be obtained, which led to the present invention. Things.

That is, the present invention provides such a core-shell polymer as polymer fine particles, and has excellent fluidity suitable for work at room temperature, viscosity increase with time during long-term storage, and excellent gelation without causing gelation. Stability, when cooled to room temperature after heat treatment, has both good compatibility with the plasticizer such that the plasticizer does not leach onto the surface of the gelled product, and furthermore, it can give a tough gelled product Can,
Thus, it is an object to provide a practical plastisol alternative to conventional polyvinyl chloride plastisol.

[0011]

SUMMARY OF THE INVENTION A plastiso according to the present invention .
Le is, (a) a core layer comprising an aromatic monovinyl monomer by polymerizing a monomer composed mainly of comprising polymer, (b) (b1) an aromatic monovinyl monomer, (b2) alpha , Β-ethylenically unsaturated carboxylic acids and α, β
At least one monomer selected from ethylenically unsaturated carboxylic acid hydroxyalkyl esters, and (b3) (meth) acrylic acid esters, vinyl cyanide
S, cyanide Biniri den ethers, carboxylic acid vinyl esters
, Unsaturated carboxylic amides , maleimides and fats
At least selected from the group conjugated diene compounds one (here, of the above monomer, (b1) 35 to 90 wt%,
(B2) is 5 to 35 % by weight, and (b3) is 10 to 60 % by weight.
(However, it does not include 60% by weight.

) . And a shell layer obtained by polymerizing a monomer mixture comprising: a core layer having a shell layer in the range of 5 to 70% by weight and a weight average particle size in the range of 0.1 to 50 μm. The polymer is dispersed in a liquid dispersion medium.
It was characterized by comprising.

The plastisol according to the invention is preferably
It is of dispersed plasticizer core-shell polymer as above
It was characterized by comprising.

First, in the plastisol according to the present invention ,
The core / shell polymer used will be described.

The core-shell polymer used Oite the present invention, multi-stage seed emulsion polymerization method or a multistage suspended heavy the polymer phase after the polymer of the previous step are continuous so as to sequentially cover It can be obtained by law. In the case of the multi-stage seed emulsion polymerization method, usually, a seed latex is prepared by emulsion polymerization by batch addition of monomers,
Seed polymerization is performed in the presence of the seed latex to obtain a core latex, and the seed polymerization is repeated in the presence of the core latex to obtain a core-shell polymer latex. Seed latex
For example, it can be obtained by adding a monomer according to the required characteristics all at once and emulsion-polymerizing this. As the monomer, styrene, methyl methacrylate, ethyl acrylate and a mixture thereof are often used.

When the core / shell polymer is produced by emulsion polymerization, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, and polyoxyethylene nonyl are used as the emulsifier in the polymerization in a conventional manner. Phenyl ether, using a nonionic surfactant such as sorbitan monolaurate or a cationic surfactant such as octadecylamine acetate, potassium persulfate as a polymerization initiator, peroxides such as cumene peroxide, 2,2 '-Azobis (2-amidinopropane)
An azo compound such as a hydrochloride can be used.

On the other hand, when the core-shell polymer is produced by suspension polymerization, upon polymerization, an organic compound such as polyvinyl alcohol, hydroxyethyl cellulose or tricalcium phosphate may be used as a protective colloid according to a conventional method. Inorganic compounds can be used, and benzoyl peroxide, 2,2′-
A peroxide such as azobisisobutyronitrile or an azo compound can be used.

Hereinafter, for the sake of simplicity, a first-stage seed polymerization for forming a core layer and a second-stage seed polymerization in the presence of a latex of polymer particles constituting such a core layer are performed. examples of two-stage polymerization method, a Oite the present invention
The production of a core-shell polymer is described.

In the first stage polymerization, a monomer containing an aromatic monovinyl monomer as a main component is polymerized to form a core layer made of a glassy polymer having good compatibility with a plasticizer. Polymerization. Here, the monomer for forming the core layer is preferably composed of a single aromatic monovinyl monomer, as described later, but contains an aromatic monovinyl monomer as a main component. It may be a mixture.

In the present invention, specific examples of the aromatic monovinyl monomer include styrene, α-methylstyrene, α-chlorostyrene, α-bromostyrene,
Examples thereof include styrene monomers such as 3,4-dichlorostyrene, alkylvinylbenzenes such as vinyltoluene and ethylvinylbenzene, and polycyclic aromatic monovinyl compounds such as vinylnaphthalene. These aromatic monovinyl monomers are used alone or in combination of two or more. In particular, in the present invention, as the aromatic monovinyl monomer, a styrene monomer is preferable, and among them,
Styrene is preferably used.

The monomer for forming the core layer used in the first-stage polymerization may contain a non-aromatic vinyl monomer copolymerizable with the aromatic monovinyl monomer. As such a non-aromatic monovinyl monomer, for example, an aliphatic conjugated diene compound having 4 to 6 carbon atoms such as butadiene, isoprene and chloroprene, for example, ethyl acrylate, propyl acrylate, butyl acrylate, cyclohexyl acrylate, 2- Examples thereof include an alkyl (meth) acrylate having an alkyl group having 1 to 10 carbon atoms such as ethylhexyl acrylate, methyl methacrylate and butyl methacrylate, vinyl cyanide such as acrylonitrile and methacrylonitrile, and vinylidene cyanide.

Further, as the non-aromatic vinyl monomer,
For example, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, particularly α, β-ethylenically unsaturated aliphatic carboxylic acids such as hydroxyethyl (meth) acrylate;
Examples thereof include hydroxyalkyl (meth) acrylates having 1 to 10 carbon atoms in an alkyl group such as hydroxypropyl (meth) acrylate, and glycidyl (meth) acrylate.

In the present invention, in the first-stage polymerization, the crosslinkable monomer is used in an amount of 5% by weight or less, preferably 2% by weight or less of the total monomers for forming the core layer. Can be used in combination. Further, the grafted monomer can be used in an amount of 5% by weight or less, preferably 2% by weight or less of the total monomers for forming the core layer.
If necessary, both a crosslinkable monomer and a grafted monomer may be used.

As described above, in the first-stage polymerization, a core-shell polymer obtained by copolymerizing a crosslinking monomer or a grafted monomer together with a monomer for forming a core layer is as follows. When this is used for a plastisol, the same effect as in the case where a crosslinking agent is added to the plastisol can be obtained as described later.

The use of crosslinkable and grafted monomers in the production of core-shell polymers has been described, for example, in US Pat. No. 4,096,202, as described in US Pat.
It is already well known. That is, the crosslinkable monomer refers to a polyfunctional monomer having two or more addition-polymerizable (ethylenic) unsaturated bonds in a molecule and having substantially the same reactivity. Such a crosslinkable monomer partially gives the polymer forming the core layer a three-dimensional network structure, that is, a crosslinked polymer structure.

As such a crosslinkable monomer, for example,
Aromatic divinyl compounds such as divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, butylene glycol diacrylate, hexanediol diacrylate, hexanediol dimethacrylate, oligoethylene glycol diacrylate, oligoethylene glycol dimethacrylate, trimethylolpropanedi Examples thereof include alkane polyol poly (meth) acrylates such as acrylate, trimethylolpropane dimethacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate.

The grafting monomer is a compound having 2
A polyfunctional monomer having one or more addition polymerizable (ethylenic) unsaturated bonds, at least one of which has a different reactivity from at least one of the remainder. Such a grafted monomer leaves an ethylenically unsaturated bond on or near the surface of the core layer after the formation of the core layer, and is polymerized on the surface of the core layer after the formation of the core layer to form a shell layer. Is formed, the ethylenically unsaturated bonds remaining on or near the surface of the core layer participate in the polymerization in which the shell layer is formed, and at least a part of the shell layer is chemically bonded to the core layer. Will be combined.

Examples of such a grafted monomer include allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl itaconate, allyl maleate (half ester), allyl fumarate (half ester), A typical example is an ethylenically unsaturated carboxylic acid allyl ester such as allyl itaconate (half ester).

In the present invention, in the first-stage polymerization, the aromatic monovinyl monomer, particularly the styrene-based monomer, which is the main component of the polymer forming the core layer, is used as a whole for the core layer. It is preferably at least 50% by weight of the monomer, particularly preferably at least 80% by weight.

From a practical point of view, in the present invention,
The core layer is preferably a polymer obtained by polymerizing substantially only styrene, or a crosslinked polymer obtained by copolymerizing a monomer mixture composed of styrene and a crosslinkable monomer.

Further, according to the present invention, the polymer forming the core layer preferably has a glass transition temperature of 30 ° C. or higher, and particularly preferably a glassy polymer having a glass transition temperature of 40 ° C. or higher.

The second-stage polymerization is a polymerization for forming a shell layer having poor compatibility with the plasticizer at room temperature, and the shell layer comprises (b1) an aromatic monovinyl monomer, and (b2) α, β-ethylenically unsaturated carboxylic acid and α, β
At least one monomer selected from ethylenically unsaturated carboxylic acid hydroxyalkyl esters, and (b3) (meth) acrylic acid esters, vinyl cyanide
, Vinylidene cyanides, vinyl carboxylate
S, unsaturated carboxylic acid amides, maleimide compounds and fatty
At least one selected from group conjugated diene compounds (wherein (b1) is 35 to 90 % by weight,
(B2) is 5 to 35 % by weight, and (b3) is 10 to 60 % by weight.
(However, it does not include 60% by weight.

) . ) Is polymerized.

In the present invention, the aromatic monovinyl monomer which is the first monomer (b1) in the monomer mixture for forming the shell layer is the main monomer forming the shell layer. The component is used in an amount of 35 to 90% by weight, preferably 45 to 85 % by weight of the total monomer mixture for forming the shell layer.

Specific examples of the aromatic monovinyl monomer (b1) as the first monomer in the monomer mixture for forming the shell layer include, for example, styrene, α-methylstyrene, Styrene monomers such as α-chlorostyrene, α-bromostyrene, and 3,4-dichlorostyrene; alkyl vinyl benzenes such as vinyl toluene and ethyl vinyl benzene; and polycyclic aromatic vinyl compounds such as vinyl naphthalene. it can. These aromatic monovinyl monomers are used alone or in combination of two or more. In particular, in the present invention, as the first aromatic monovinyl monomer (b1), a styrene-based monomer is preferable, and among them, styrene is most preferably used.

In the present invention, as the α, β-ethylenically unsaturated carboxylic acid as the second monomer (b2) in the monomer mixture for forming the shell layer, acrylic acid, methacrylic acid Acid, α-ethylacrylic acid, β-ethylacrylic acid, α, β-dimethylacrylic acid and the like can be mentioned. Of these, methacrylic acid is particularly preferably used. Examples of the α, β-ethylenically unsaturated carboxylic acid include unsaturated dicarboxylic acids such as itaconic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, methylenemalonic acid, α-methyleneglutaric acid, and half esters thereof. Can also be used.

As the α, β-ethylenically unsaturated carboxylic acid hydroxyalkyl ester, hydroxyethyl acrylate, hydroxypropyl acrylate,
Hydroxyethyl methacrylate and the like are preferably used. Of these, hydroxyethyl methacrylate is particularly preferably used.

Particularly, in the present invention, methacrylic acid, 2-hydroxyethyl (meth) acrylate or a mixture thereof is preferably used as the second monomer (b2).

These second monomers (b2) account for 5 to 35% by weight of the total monomer mixture used for forming the shell layer.
Preferably, it is used in the range of 5 to 30% by weight.

Further, in the present invention, as the other third monomer (b3) having copolymerizability with the first monomer (b1) and the second monomer (b2), Monomers such as (meth) acrylic esters, vinyl cyanides, vinylidene cyanides, vinyl carboxylate esters, unsaturated carboxylic amides, maleimides, and aliphatic conjugated diene compounds can be used.

Among such third monomers (b3),
Examples of the (meth) acrylate include acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and glycidyl acrylate, methyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate. Examples thereof include methacrylic acid esters such as glycidyl methacrylate. Examples of vinyl cyanide or vinylidene cyanide include acrylonitrile, methacrylonitrile and the like. Examples of the vinyl carboxylate include vinyl acetate and vinyl propionate. Examples of unsaturated carboxylic amides include (meth) acrylamide,
N-methylolacrylamide, N-butoxymethylacrylamide and the like can be mentioned. Examples of the maleimides include N-phenylmaleimide. In addition, examples of the aliphatic conjugated diene compounds include butadiene, isoprene, chloroprene, and the like.

Among these third monomers (b3), methyl methacrylate, acrylonitrile and the like are particularly preferably used.

In the present invention, the third monomer (b3) accounts for 10 to 60% by weight (but not including 60% by weight ) of the total monomer mixture used for forming the shell layer.
No. ) .

In the present invention, even in the second stage polymerization, the above-mentioned crosslinkable monomer or grafted monomer may be used in an amount of 5% by weight or less of the total monomers for forming the shell layer. Monomers can be used in combination.

In the present invention, the polymer forming the shell layer has a glass transition temperature of 40 ° C. or higher, preferably 50 ° C.
A glassy polymer that has a very low or no compatibility with plasticizers at room temperature at a temperature of at least ℃ and compatibilizes with the plasticizer when heated to an appropriate temperature. Is a polymer having

According to the present invention, such a core-shell
The ratio of the core layer and the shell layer in the polymer is appropriately selected depending on the degree of compatibility with each plasticizer. According to the present invention, in the core-shell polymer, the shell layer is preferably 5 ~ 70% by weight,
Particularly preferably, it is in the range of 20 to 50% by weight. Thus, the core layer preferably ranges from 30 to 95% by weight, particularly preferably from 50 to 80% by weight, in the core-shell polymer.

The gel obtained by heat-treating a plastisol containing such a core-shell polymer has a core layer having good compatibility with the plasticizer and a shell layer having poor compatibility with the plasticizer. When present, but when the shell layer exceeds 70% by weight of the core-shell polymer, the gel becomes brittle and
May be inferior in toughness. On the other hand, when the amount of the shell layer is less than 5% by weight, the coating of the core layer with the shell layer becomes insufficient, and the storage stability may decrease.

[0048] The present invention is used Oite the core-shell polymer is basically a core layer of higher compatibility with the plasticizer, the shell layer of hardly soluble or incompatible with the plasticizer at room temperature However, if necessary, each of the core layer and the shell layer may be formed of a plurality of layers.

[0049] The present invention is used Oite the core-shell polymer, for example, when manufacturing the already-known seed emulsion polymerization method is a weight average particle diameter of 0.1 to 5 [mu] m, preferably 0.3 to If a latex in the range of 2 μm, more preferably 0.5 to 1 μm is produced, and the resulting polymer particles are separated from the reaction system by freeze-thawing or salting out, then centrifugally dehydrated and dried, It can be obtained as a powder. When the weight average particle diameter of the obtained core-shell polymer is smaller than 0.1 μm, the core layer is insufficiently covered with the shell layer and is dispersed in a liquid dispersion medium for use as a plastisol. In addition, storage stability may deteriorate. On the other hand, when the weight average particle diameter of the core-shell polymer is larger than 5 μm, it takes a long time for polymerization, which is not preferable in practical use.

[0050] On the other hand, when producing a core-shell polymer used Oite the present invention by suspension polymerization of two stages,
Usually, a suspension having a weight average particle diameter of 5 to 50 μm is prepared,
If this is centrifugally dehydrated and dried, it can be obtained as a powder. The core-shell polymer has a weight average particle size of 50 μm
If it is larger than this, it may take an unnecessarily long time to obtain a gel by heating the obtained plastisol.

When the latex or the suspension is spray-dried using a spray drier, the core-shell polymer can be immediately obtained as a powder from them.

The plastisol according to the present invention can be obtained by dispersing the above-mentioned core-shell polymer in a suitable liquid dispersion medium, preferably a liquid plasticizer. The plasticizer used in the present invention is compatible with the core layer of the core-shell polymer at room temperature and is not compatible with the shell layer, but by heating to an appropriate temperature,
When compatible with the shell layer and then cooled to room temperature,
It forms a gel with strength and toughness, ie, plastigel.

The plasticizer that can be used in the present invention is not particularly limited, and may be any plasticizer that has been conventionally used for producing polyvinyl chloride plastisol. Phthalic acid diesters such as dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, ditridecyl phthalate, dilauryl phthalate, octyl decyl phthalate, distearyl phthalate, butyl benzyl phthalate, dibenzyl phthalate, dioctyl adipate, etc. Adipic acid diester, sebacic acid diester such as dioctyl sebacate, tributyl phosphate, tris (2-ethylhexyl) phosphate, tricresyl phosphate, cresyl diphenyl phosphate Feto, diphenyl octyl phosphate, phosphoric acid organic esters such as triisopropyl phenyl phosphate, epoxy plasticizers such as epoxidized soybean oil, and polyester-based plasticizers.

The amount of the plasticizer in the plastisol according to the present invention affects the fluidity of the plastisol and the physical properties of the gelled product, and is appropriately selected according to the required physical properties. It is in the range of 50 to 200 parts by weight with respect to 100 parts by weight of the combined.

According to the present invention, a cross-linking agent may be added to the plastisol in order to impart more tough physical properties to a coating or a molded product formed by heat-treating the plastisol. Here, the cross-linking agent refers to a functional group which reacts with a carboxyl group and / or a hydroxyl group of the shell layer in the molecule.
A compound having at least one functional group such as an epoxy group, an amino group, an isocyanate group, a blocked isocyanate group, a hydroxyl group,
-Methylol group, N-alkoxymethyl group and the like. In the present invention, among these, a compound having two or more epoxy groups in a molecule is particularly preferably used as a crosslinking agent.

As the compound having an epoxy group,
For example, glycidyl ether-based epoxy resins such as bisphenol A-based, bisphenol F-based, and novolac type, glycidyl ester-based epoxy resins such as glycidyl ester of polycarboxylic acid, cycloaliphatic epoxy resins, glycidylamine-based epoxy resins, and heterocyclic epoxy resins Resins and the like can be mentioned. Among them, particularly, in the present invention, a flexible epoxy resin containing a polyethylene oxide chain or the like in a molecule is preferably used.

In the present invention, such a crosslinking agent is used.
Usually, 0.1 parts by weight per 100 parts by weight of the core-shell polymer.
To 50 parts by weight, preferably 0.5 to 20 parts by weight.

Further, in addition to the above, the plastisol according to the present invention may be added, if necessary, with an appropriate amount of a diluent, an inorganic filler, an organic filler, a dye, a pigment, a corrosion inhibitor and the like. .

Such a plastisol according to the present invention comprises:
At room temperature, it has excellent workability and fluidity and storage stability. Usually, it is heat-treated at 100 to 180 ° C. to be solidified and solidified. To give a gelled product having
It can be advantageously used for forming a protective coating for automobiles.

[0060]

As described above, in the plastisol according to the present invention, the core layer is mainly composed of an aromatic monovinyl monomer, preferably a polymer obtained by polymerizing styrene, and the shell layer is composed of an aromatic monomer. A group monovinyl monomer, preferably, having a core-shell polymer obtained by polymerizing a monomer mixture containing styrene as a main component as a polymer component,
It is excellent in fluidity, storage stability and compatibility, and furthermore, such a plastisol gives a film or a molded product as a tough gelled product, so that instead of the conventional plastisol containing polyvinyl chloride as a polymer component, Can be practical.

[0061]

The present invention will be described below with reference to examples and comparative examples together with reference examples, but the present invention is not limited to these examples. In the following, "part"
All indicate parts by weight. Abbreviations used below are as shown below. Abbreviations Methyl methacrylate: MMA Butyl methacrylate: BMA 2-hydroxyethyl methacrylate: HEMA Methacrylic acid: MAA Styrene: St Acrylonitrile: AN 1,4-butylene glycol diacrylate BGDA 1,6-hexanediol diacrylate HDDA Deionized water: DIW Dioctyl sulfosuccinate sodium salt: SSS Sodium persulfate: SPS Sodium bicarbonate: SHC Diisononyl phthalate: DINP 1,4-diazabicyclo [2,2,2] octane: DABCO Method for measuring physical properties of core-shell polymer Core-shell weight The weight average particle diameter of the combined particles was measured by a laser particle size analysis system LPA-3000 manufactured by Otsuka Electronics Co., Ltd.

The strength at break and the elongation at break were determined by pressing a plastisol at a temperature of 140 ° C. and a pressure of 100 kgf / cm ^{2 for} 30 minutes to form a sheet having a thickness of about 1 mm. It measured according to -6301.

The storage stability was maintained at 40 ° C. for 10 days, and the storage stability was defined as good when no gelation occurred. Reference Example 1 (Production of core-shell polymer A) DI was placed in a 3-liter polymerization vessel equipped with a reflux condenser.
19 parts of W, 0.3 parts of 1% SSS aqueous solution and 1.3 parts of 1% SHC aqueous solution were charged, and stirred at 70 ° C. under a nitrogen stream.
The temperature rose. Next, 0.3 parts of St was added thereto and dispersed for 10 minutes, and then 7.5 parts of a 2% aqueous SPS solution was added to start seed emulsion polymerization.

After reacting for 10 minutes to prepare a seed latex, 59.7 parts of St and a 1% aqueous solution of SSS 5 were added thereto.
A monomer emulsion for the first stage polymerization consisting of 0 parts and 9 parts of a 1% SHC aqueous solution is continuously supplied over 6 hours,
Next, the internal temperature was raised from 70 ° C. to 90 ° C., and the mixture was aged for 1 hour.

Next, the internal temperature was adjusted to 70 ° C., and 2% SPS
After adding 2 parts of aqueous solution, 28 parts of St, 6 parts of MAA, MM
A, a monomer emulsion for the second stage polymerization consisting of 6 parts of 1% SSS aqueous solution, 2 parts of 1% SHC aqueous solution and 30 parts of DIW was continuously supplied over 4 hours. The temperature was raised from 70 ° C. to 90 ° C. and aged for 1 hour.

After the completion of the reaction, the reaction mixture was cooled to room temperature, filtered through a 300-mesh wire gauze to obtain a solid content of 44.0.
% Of a core-shell polymer latex having a weight average particle diameter of 680 nm. This latex was spray-dried to obtain a core-shell polymer A powder. Reference Examples 2 to 7 and Comparative Example 1 (Preparation of Core-Shell Polymers B to H) In the same manner as in Reference Example 1, a core having the composition shown in Table 1 was prepared.
Powders of shell polymers BH were prepared.

[0067]

[Table 1]

Examples 1 to 8 and Comparative Example 2 (Preparation of plastisol and evaluation of its physical properties) As shown in Table 2, core-shell polymers A to H obtained in Reference Examples 1 to 7 and Comparative Example 1 Was mixed with a plasticizer, a cross-linking agent and a catalyst and uniformly dispersed to prepare a plastisol.
Table 2 shows the storage stability of the obtained plastisol and the physical properties of the film obtained from the plastisol.

[0069]

[Table 2]

Continuation of the front page (56) References JP-A-6-9730 (JP, A) JP-A-5-194681 (JP, A) JP-A-6-65331 (JP, A) (58) Fields studied (Int) .Cl. ⁷ , DB name) C08F 257/02 C08F 20/18 C08L 51/00

Claims (13)

(57) [Claims] (1) a core layer comprising a polymer obtained by polymerizing a monomer having an aromatic monovinyl monomer as a main component, (b) (b1) an aromatic monovinyl monomer, ) Α, β-ethylenically unsaturated carboxylic acid and α, β
At least one monomer selected from ethylenically unsaturated carboxylic acid hydroxyalkyl esters, and (b3) (meth) acrylic acid esters, vinyl cyanide
S, cyanide Biniri den ethers, carboxylic acid vinyl esters
, Unsaturated carboxylic amides , maleimides and fats
At least selected from the group conjugated diene compounds one (here, of the above monomer, (b1) 35 to 90 wt%,
(B2) is 5 to 35 % by weight, and (b3) is 10 to 60 % by weight.
(However, not including 60% by weight ) . A) a shell layer obtained by polymerizing a monomer mixture comprising: (a) a core layer having a shell layer in the range of 5 to 70% by weight and a weight average particle diameter in the range of 0.1 to 50 μm; polymerization
A plastisol obtained by dispersing a body in a liquid dispersion medium . 2. A monomer for forming the core layer comprises a crosslinkable monomer, consists of a polymer core layer is crosslinked copolymer
The plastisol according to claim 1 , comprising a shell polymer . 3. The core-shell weight wherein at least 50% by weight of a monomer for forming a core layer is an aromatic monovinyl monomer.
The plastisol according to claim 1, comprising coalescence . 4. The core-shell weight wherein the aromatic monovinyl monomer in the monomer for forming the core layer is styrene.
The plastisol according to claim 1, comprising coalescence . 5. The plastisol according to claim 1, wherein the core layer contains a core-shell polymer composed of a glassy polymer having a glass transition point of 30 ° C. or higher. 6. A monomer mixture for forming a shell layer, wherein (b1) is styrene, (b2) is methacrylic acid,
A core-shell polymer wherein (b3) is at least one selected from methyl methacrylate and acrylonitrile
The plastisol of claim 1 comprising : 7. The core layer is substantially composed of a non-crosslinked polymer or crosslinked polymer of styrene, and the shell layer is substantially composed of (b1) styrene, (b2) methacrylic acid and (b3) methyl methacrylate and acrylonitrile. A core-shell polymer comprising at least one copolymer selected from
The plastisol of claim 1 comprising : 8. The shell layer is in the range of 20 to 50% by weight.
2. The plastizo of claim 1 comprising a core-shell polymer.
Le . 9. The plastisol according to claim 1 , wherein the liquid dispersion medium is a plasticizer. 10. wherein the plasticizer is a phthalic acid diester
Item 10. A plastisol according to item 9 . 11. The plastisol according to claim 1, further comprising a crosslinking agent having at least two functional groups in the molecule that react with carboxyl groups and / or hydroxyl groups of the core-shell polymer. 12. The plastisol according to claim 11, wherein the crosslinking agent is a compound having two or more epoxy groups in a molecule. 13. The plastisol according to claim 11, wherein the crosslinking agent is contained in an amount of 0.1 to 50 parts by weight per 100 parts by weight of the core-shell polymer.