JP2021095548A - Polymer fine particle and resin composition - Google Patents

Abstract

To provide a novel polymer fine particle having excellent blocking resistance and transparency, and a resin composition containing the polymer fine particle.SOLUTION: A polymer fine particle has a core layer having a core inner layer and a specific amount of a core outer layer, and a shell layer. The difference between a refractive index of the core layer and a refractive index of the shell layer is 0-0.003 in absolute value. The core inner layer, the core outer layer and the shell layer each have a Hansen solubility parameter satisfying a specific constitution.SELECTED DRAWING: None

Description

The present invention relates to polymer fine particles and resin compositions.

In order to improve the strength and impact resistance of the molded product of the thermoplastic resin or the cured product of the thermosetting resin, an elastomer, particularly polymer fine particles, is added to the resin composition of the thermoplastic resin or the thermosetting resin. The method is widely used.

For example, Patent Document 1 discloses the following acrylic resin film as a coating substitute: a thermoplastic polymer (I) having a specific composition (I) 75 to 94.5 parts by mass, and a rubber having a specific composition. An elastic polymer containing 5.5 to 25 parts by mass of the contained polymer (II) and composed of the innermost layer polymer (II-A) and the rubber polymer (II-B) in the rubber-containing polymer (II). A coating substitute acrylic resin film characterized in that the amount of ((II-A) + (II-B)) is 5 to 18 parts by mass [a total of 100 parts by mass of the component (I) and the component (II)]. ..

JP-A-2002-080679

However, the above-mentioned conventional technique has a problem that secondary particles of polymer fine particles (rubber-containing polymer) added to a thermoplastic resin (thermoplastic polymer) tend to adhere to each other and are inferior in blocking resistance. ..

Further, transparency may be required for the molded product of the thermoplastic resin or the cured product of the thermosetting resin. In such a case, the polymer fine particles added to the resin composition of the thermoplastic resin or the thermosetting resin are also required to be transparent.

One embodiment of the present invention has been made in view of the above problems and the like, and an object of the present invention is to obtain a novel polymer fine particles having excellent blocking resistance and transparency, and a resin composition containing the polymer fine particles. To provide.

The present inventors have diligently studied to solve the above-mentioned problems. As a result, the present inventors can solve the above-mentioned problems by having a core layer having a core inner layer and a core outer layer and a shell layer, and setting the refractive index and Hansen solubility parameter of each layer within a specific range. It was discovered for the first time and led to the completion of the present invention.

That is, one embodiment of the present invention includes the following configurations.
[1] A core layer having a core inner layer which is the innermost layer and a core outer layer formed so as to cover at least a part of the core inner layer, and a shell layer formed so as to cover at least a part of the core outer layer. The absolute value of the difference between the refractive value of the core layer and the refractive value of the shell layer is 0 to 0.003, and the core layer contains the core outer layer in 100% by weight of the core layer. Polymer fine particles containing 2% by weight to 20% by weight and satisfying all of (i) to (iii) below: (i) 0.3 ≦ | δ _{A −} δ _B |, (ii) 0.3 ≦ | Δ _{B −} δ _C | and (iii) 0.1 ≧ | δ _{A −} δ _C |; where δ _A is the Hansen solubility parameter of the polymer constituting the inner layer of the core, and δ _B is , The Hansen solubility parameter of the monomer constituting the core outer layer, and δ _C is the Hansen solubility parameter of the monomer constituting the shell layer.
[2] The core inner layer has (i) a structural unit derived from (i-1) alkyl acrylate (unit a) of 50% by weight to 90% by weight, and (i-2) an aromatic vinyl-based compound. 10% to 50% by weight of the structural unit (unit b) derived from (i-3) the alkyl acrylate and / or the aromatic vinyl-based compound capable of copolymerizing with the alkyl acrylate and / or the aromatic vinyl-based compound. It contains 0% by weight to 20% by weight of a structural unit (unit c) derived from a vinyl-based compound other than the compound, and (ii) the total of the unit a, the unit b and the unit c is 100% by weight. , [1].
[3] The shell layer has (i) structural units derived from (i-1) alkyl acrylate (unit a) of 85% by weight to 97% by weight, and (i-2) aromatic vinyl-based compound. 3% to 15% by weight of the structural unit (unit b) derived from (i-3) the alkyl acrylate and / or the aromatic vinyl-based compound capable of copolymerizing with the alkyl acrylate and / or the aromatic vinyl-based compound. It contains 0% by weight to 12% by weight of a structural unit (unit c) derived from a vinyl-based compound other than the compound, and (ii) the total of the unit a, the unit b and the unit c is 100% by weight. , [1] or [2].
[4] The core outer layer has (i) a structural unit derived from (i-1) alkyl acrylate (unit a) of 90% by weight to 100% by weight, and (i-2) an aromatic vinyl-based compound. (Unit b) 0% by weight to 10% by weight and (i-3) the alkyl acrylate and / or the aromatic vinyl-based compound capable of copolymerizing with the alkyl acrylate and / or the aromatic vinyl-based compound. It contains 0% by weight to 10% by weight of a structural unit (unit c) derived from a vinyl-based compound other than the compound, and (ii) the total of the unit a, the unit b and the unit c is 100% by weight. , The polymer fine particles according to any one of [1] to [3].
[5] The surface of the polymer fine particles further contains an anti-blocking agent, the core outer layer has a glass transition temperature of −60 ° C. to 30 ° C., and the core outer layer is a polyfunctional monomer as a constituent unit. And / or a structural unit derived from the crosslinkable monomer is further contained, and the total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the core outer layer is , 0.1% by weight to 1.0% by weight, based on 100% by weight of all the constituent units derived from the monomers other than the polyfunctional monomer and the crosslinkable monomer in the core outer layer. 1] The polymer fine particles according to any one of [4].
[6] The polymer fine particles according to any one of [1] to [5] and the matrix resin are contained, and the absolute difference between the refractive index of the polymer fine particles and the refractive index of the matrix resin is absolute. A resin composition having a value of 0 to 0.003.

According to one embodiment of the present invention, it is possible to provide polymer fine particles having excellent blocking resistance and transparency, and a resin composition containing the polymer fine particles.

An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications can be made within the scope of the claims. The technical scope of the present invention also includes embodiments or examples obtained by combining the technical means disclosed in different embodiments or examples. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. In addition, all the academic documents and patent documents described in the present specification are incorporated as references in the present specification. Further, unless otherwise specified in the present specification, "A to B" representing a numerical range is intended to be "A or more (including A and larger than A) and B or less (including B and smaller than B)".

[1. Technical Thought of One Embodiment of the Present Invention]
The present inventor has made diligent studies in order to obtain polymer fine particles having excellent transparency. As a result, the transparency of the polymer fine particles having the core layer and the shell layer, that is, having the core-shell structure is excellent by keeping the difference between the refractive index of the core layer and the refractive index of the shell layer within a certain range. We obtained a new finding that polymer fine particles can be obtained. Furthermore, the inventor has stated that the difference between the refractive index of the core layer and the refractive index of the shell layer is within a certain range, and polymer fine particles having excellent transparency tend to be inferior in blocking resistance, and thus have blocking resistance. We independently obtained the finding that there is room for improvement in this respect. The inventor has diligently investigated the cause of the inferior blocking resistance of polymer fine particles having excellent transparency. As a result, the present inventor has independently found that the reason why the polymer fine particles having excellent transparency are inferior in blocking resistance is as follows: (a) In the polymer fine particles having excellent transparency, the shell layer Has entered the core layer, the shell layer does not cover the core layer, and most of the core layer is exposed on the outermost surface of the polymer fine particles; and (b) as a result, the polymer fine particles are separated from each other. It is easy to stick and the polymer fine particles are inferior in blocking resistance. As a result of diligent studies based on such new findings, the present inventor has found the following findings for the first time and has completed the present invention: each layer has a core layer and a shell layer having a core inner layer and a core outer layer. By setting the refractive index and Hansen solubility parameter of the above within a specific range, polymer fine particles having excellent both blocking resistance and transparency can be obtained.

[2. Polymer fine particles]
The polymer fine particles according to one embodiment of the present invention include a core layer having a core inner layer which is the innermost layer and a core outer layer formed so as to cover at least a part of the core inner layer, and at least one of the core outer layers. It has a shell layer formed so as to cover the portion. The absolute value of the difference between the refractive index of the core layer and the refractive index of the shell layer is 0 to 0.003, and the core layer contains 2% by weight to 20% by weight of the outer core layer in 100% by weight of the core layer. Contains% by weight. The polymer fine particles according to one embodiment of the present invention satisfy all of (i) to (iii) below: (i) 0.3 ≦ | δ _{A −} δ _B |, (ii) 0.3 ≦ | δ _{B −} δ _C |, and (iii) 0.1 ≧ | δ _{A −} δ _C |. Here, δ _A is the Hansen solubility parameter of the monomer constituting the core inner layer, δ _B is the Hansen solubility parameter of the monomer constituting the core outer layer, and δ _C is the shell layer. This is the Hansen solubility parameter of the monomer constituting the above.

"Polymer fine particles according to one embodiment of the present invention" may be hereinafter referred to as "polymer fine particles". The present polymer fine particles become a resin composition when mixed with a matrix resin described later.

Since the present polymer fine particles have the above-mentioned structure, the absolute value of the difference between the refractive index of the core layer and the refractive index of the shell layer is 0 to 0.003, and the core layer is 100% by weight of the core layer. Since the core outer layer is contained in an amount of 20% by weight or less, it has an advantage of excellent transparency. Since the present polymer fine particles have the above-mentioned structure, in particular, since they have a core layer and a shell layer, it can be said that they have a core-shell structure. Since the present polymer fine particles have the above-mentioned structure, in particular, the core outer layer in which the absolute value of the difference in the Hansen solubility parameter with respect to each of the core inner layer and the shell layer is 0.3 or more is contained in 100% by weight of the core layer. Since it contains 2% by weight or more, the core-shell structure is clear. In other words, in the present polymer fine particles, the shell layer does not easily enter the core layer, and the shell layer widely covers the core layer. As a result, the present polymer fine particles have an advantage of being excellent in blocking resistance.

Hereinafter, each aspect of the core inner layer, the core outer layer, the core layer, and the shell layer in the present polymer fine particles will be described in detail. Unless otherwise specified, the following aspects relating to the core layer may be applied only to the core inner layer, may be applied only to the core outer layer, and may be applied to both the core inner layer and the core outer layer. May be good.

(2-1. Core layer)
The core layer has an inner layer of the core, which is the innermost layer, and an outer layer of the core formed so as to cover at least a part of the inner layer of the core. The core outer layer preferably covers the entire circumference of the core inner layer. The core outer layer is preferably in contact with (adjacent to) both the core inner layer and the shell layer. According to this configuration, since the shell layer is in contact with the core outer layer satisfying the above (ii), the possibility that the shell layer enters the core layer is reduced. As a result, the obtained polymer fine particles have an advantage of being excellent in blocking resistance. The core outer layer preferably covers the entire circumference of the core inner layer. According to this configuration, since the shell layer is in contact with only the core outer layer satisfying the above (ii), the possibility that the shell layer enters the core layer is further reduced. As a result, the obtained polymer fine particles have an advantage that they are more excellent in blocking resistance. The core layer may be provided with a layer between the inner layer of the core and the outer layer of the core.

The core layer is preferably an elastic body. The core layer preferably has a layer made of an elastic body having properties as rubber, and more preferably the inner layer of the core is a layer made of an elastic body. According to this structure, the obtained molded product or cured product of the resin composition has an advantage of excellent toughness. The core layer may have a layer made of an inelastic body as a core inner layer, a core outer layer or another layer.

The composition of the core layer is not particularly limited. Examples of the core layer include natural rubber, diene-based rubber, acrylate-based rubber, and organosiloxane-based rubber. The core layer preferably contains at least one selected from the group consisting of diene-based rubbers, acrylate-based rubbers, and organosiloxane-based rubbers. The elastic body may contain natural rubber in addition to the rubber described above. The elastic body can also be rephrased as an elastic portion or rubber particles.

The diene-based rubber is an elastic body containing a structural unit derived from a diene-based monomer as a structural unit. When the core layer contains a diene rubber, the obtained resin composition containing the polymer fine particles can provide a molded product or a cured product having excellent toughness and impact resistance.

Examples of the diene-based monomer include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2-chloro-1,3-butadiene and the like. Only one kind of these diene-based monomers may be used, or two or more kinds thereof may be used in combination.

The diene-based rubber may contain, as a structural unit, a structural unit derived from a vinyl-based monomer other than the diene-based monomer copolymerizable with the diene-based monomer. Examples of the vinyl-based monomer (hereinafter, also referred to as vinyl-based monomer A) other than the diene-based monomer copolymerizable with the diene-based monomer include aromatic vinyl-based compounds and vinyl cyanide. Examples include system compounds, unsaturated carboxylic acids and unsaturated carboxylic acid esters.

Examples of aromatic vinyl compounds include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene, and dichlorostyrene. , Bromstyrene, dibromstyrene and the like are preferable.

Preferable examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile.

Preferred examples of unsaturated carboxylic acid include acrylic acid and methacrylic acid.

Preferable examples of the unsaturated carboxylic acid ester include an acrylic acid ester having an alkyl ester having 1 to 12 carbon atoms and a methacrylic acid ester having an alkyl ester having 1 to 12 carbon atoms.

As the vinyl-based monomer A, only one type may be used, or two or more types may be used in combination. Among the vinyl-based monomer A, styrene is particularly preferable.

Examples of the diene rubber include (a) butadiene rubber composed of only constituent units derived from 1,3-butadiene, (b) butadiene-styrene rubber which is a copolymer of 1,3-butadiene and styrene, and (c). Acrylonitrile-butadiene rubber, which is a copolymer of acrylonitrile and 1,3-butadiene, and (d) butadiene-acrylic acid ester copolymer, which is a copolymer of 1,3-butadiene and an acrylic acid ester monomer. Coalescence etc. can be mentioned. The butadiene-styrene rubber can enhance the transparency of the obtained molded product or cured product by adjusting the refractive index.

The acrylate-based rubber is an elastic body containing a structural unit derived from a (meth) acrylate-based monomer as a structural unit. When the core layer contains an acrylate-based rubber, it is possible to design a core layer having a composition of various structural units by combining various monomers. As used herein, (meth) acrylate means acrylate and / or methacrylate.

Examples of the (meth) acrylate-based monomer include (a) methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, and dodecyl (). Alkyl (meth) acrylates such as meta) acrylates, stearyl (meth) acrylates and behenyl (meth) acrylates; (b) aromatic ring-containing (meth) acrylates such as phenoxyethyl (meth) acrylates and benzyl (meth) acrylates; (C) Hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; (d) glycidyl (meth) acrylate, glycidylalkyl (meth) acrylate, 4-hydroxybutyl Examples thereof include glycidyl (meth) acrylates such as (meth) acrylate glycidyl ether; and (e) alkoxyalkyl (meth) acrylates. Only one kind of these (meth) acrylate-based monomers may be used, or two or more kinds thereof may be used in combination.

The (meth) acrylate-based rubber may contain a structural unit derived from a vinyl-based monomer other than the (meth) acrylate-based monomer copolymerizable with the (meth) acrylate-based monomer as a structural unit. Good. Examples of the vinyl-based monomer (hereinafter, also referred to as vinyl-based monomer B) other than the (meth) acrylate-based monomer copolymerizable with the (meth) acrylate-based monomer include the above-mentioned diene. Examples thereof include based monomers, aromatic vinyl-based compounds and vinyl cyanide-based compounds, unsaturated carboxylic acids and unsaturated carboxylic acid esters. As the vinyl-based monomer B, only one type may be used, or two or more types may be used in combination.

When the core layer contains an organosiloxane-based rubber, the resin composition containing the obtained polymer fine particles can provide a molded product or a cured product having sufficient heat resistance and excellent impact resistance at a low temperature. it can.

The organosiloxane-based rubber is composed of alkyl or aryl disubstituted silyloxy units such as (a) dimethylsilyloxy, diethylsilyloxy, methylphenylsilyloxy, diphenylsilyloxy and dimethylsilyloxy-diphenylsilyloxy. Organosiloxane-based polymers, and (b) organosiloxane-based polymers composed of alkyl or aryl1-substituted silyloxy units, such as (b) organohydrogensilyloxy in which part of the side chain alkyl is substituted with hydrogen atoms. Can be mentioned. Only one kind of these organosiloxane-based polymers may be used, or two or more kinds thereof may be used in combination.

The inner layer of the core preferably contains (i) a structural unit (unit a) derived from an alkyl acrylate and (ii) a structural unit (unit b) derived from an aromatic vinyl compound as a structural unit. The inner layer of the core is a structural unit (unit c) derived from an alkyl acrylate and a vinyl compound other than the aromatic vinyl compound, which can be optionally copolymerized with an alkyl acrylate and / or an aromatic vinyl compound. May be further contained. Examples of the unit c include a (meth) acrylate-based monomer other than the alkyl acrylate and / or a structural unit derived from the vinyl-based monomer A other than the aromatic vinyl compound. When the inner layer of the core contains the unit a, the unit b, and optionally the unit c as the constituent units, the obtained polymer fine particles have an advantage of being more excellent in blocking resistance.

In the inner layer of the core, the unit a is a structural unit derived from one or more alkyl acrylates selected from the group consisting of methyl methacrylate and butyl acrylate because it is inexpensive and stably supplied. More preferably, it is a structural unit derived from methyl methacrylate and a structural unit derived from butyl acrylate.

In the inner layer of the core, the unit b is preferably styrene because it has high thermal stability, is inexpensive, and is stably supplied.

The inner layer of the core has (i) 50% by weight to 90% by weight of unit a, 10% to 50% by weight of unit b, and 0% by weight of unit c of 100% by weight of the total of unit a, unit b and unit c as constituent units. It is preferable to have ~ 20% by weight, and (ii) it is more preferable to have a unit a55% by weight to 85% by weight, a unit b15% by weight to 45% by weight, and a unit c0% by weight to 15% by weight. (Iii) It is more preferable to have a unit a 60% by weight to 80% by weight, a unit b20% by weight to 40% by weight, and a unit c0% by weight to 10% by weight, and (iv) a unit a65% by weight to 75% by weight. It is more preferable to have a unit b25% by weight to 35% by weight and a unit c0% by weight to 5% by weight, and (v) a unit a66% by weight to 72% by weight and a unit b28% by weight to 34% by weight. Is particularly preferable. Since the present polymer fine particles contain a core outer layer having a specific constitution, even if the core inner layer contains the unit b in the above-mentioned range, the possibility that the shell layer enters the core layer is small. As a result, the obtained polymer fine particles have an advantage that they are further excellent in blocking resistance.

The core outer layer preferably contains a structural unit (unit a) derived from alkyl acrylate as a structural unit. The core outer layer can be optionally copolymerized with (i) a structural unit (unit b) derived from an aromatic vinyl compound and / or (ii) an alkyl acrylate and / or an aromatic vinyl compound as a structural unit. In addition, a structural unit (unit c) derived from a vinyl compound other than the alkyl acrylate and the aromatic vinyl compound may be further contained. Examples of the unit c include a (meth) acrylate-based monomer other than the alkyl acrylate and / or a structural unit derived from the vinyl-based monomer A other than the aromatic vinyl compound. When the core outer layer contains the unit a and optionally the unit b and / or the unit c as a constituent unit, the obtained polymer fine particles have an advantage of being more excellent in blocking resistance.

In the outer layer of the core, the unit a is a structural unit derived from one or more alkyl acrylates selected from the group consisting of methyl methacrylate and butyl acrylate because it is inexpensive and stably supplied. More preferably, it is a structural unit derived from methyl methacrylate and a structural unit derived from butyl acrylate.

The core outer layer has (i) unit a 90% by weight to 100% by weight, unit b0% by weight to 10% by weight, and unit c0% by weight in the total 100% by weight of unit a, unit b, and unit c as constituent units. It is preferable to have 10% by weight, and (ii) it is more preferable to have a unit a92% by weight to 100% by weight, a unit b0% by weight to 8% by weight, and a unit c0% by weight to 8% by weight. (Iii) It is more preferable to have a unit a95% by weight to 100% by weight, a unit b0% by weight to 5% by weight, and a unit c0% by weight to 5% by weight, and (iv) a unit a97% by weight to 100% by weight. It is more preferable to have the unit b0% by weight to 3% by weight and the unit c0% by weight to 3% by weight, and (v) it is particularly preferable to have the unit a100% by weight, that is, to have only the unit a. By using these configurations as the constituent units of the core outer layer, the above (i) and (ii) can be easily satisfied. As a result, the obtained polymer fine particles have an advantage that they are further excellent in blocking resistance.

(Cross-linked structure of core layer)
It is preferable that a crosslinked structure is introduced into the core layer because the dispersion stability of the polymer fine particles in the matrix resin can be maintained. As a method of introducing the crosslinked structure into the core layer, a generally used method can be adopted. As the introduction method, for example, in the production of the core layer, a cross-linking monomer such as a polyfunctional monomer and / or a mercapto group-containing compound is used as a cross-linking agent for the monomer that can form the core layer. Examples include a method of mixing and then polymerizing. In the present specification, producing a polymer such as a core layer is also referred to as polymerizing a polymer. In the present specification, a crosslinkable monomer such as (a) a polyfunctional monomer and (b) a mercapto group-containing compound may be referred to as a “crosslinking agent”.

In addition, as a method for introducing a crosslinked structure into an organosiloxane-based rubber, the following methods can also be mentioned: (a) When polymerizing an organosiloxane-based rubber, a polyfunctional alkoxysilane compound and other materials are used. (B) A reactive group such as a vinyl-reactive group or a mercapto group is introduced into an organosiloxane-based rubber, and then a vinyl-polymerizable monomer or an organic peroxide is added to cause a radical reaction. Method or (c) When polymerizing an organosiloxane-based rubber, a crosslinkable monomer such as a polyfunctional monomer and / or a mercapto group-containing compound is mixed with another material, and then the polymerization is carried out. ,Such.

A polyfunctional monomer can be said to be a monomer having two or more radically polymerizable reactive groups in the same molecule. The radically polymerizable reactive group is preferably a carbon-carbon double bond. The polyfunctional monomer does not contain butadiene and has an ethylenically unsaturated double bond such as allyl (meth) acrylates, allylalkyl (meth) acrylates and allyloxyalkyl (meth) acrylates. Examples include (meth) acrylate. Specific examples of the polyfunctional monomer include monomers having two or more (meth) acrylic groups. Examples of the monomer having two (meth) acrylic groups include ethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate, and cyclohexanedimethanol. Di (meth) acrylates and polyethylene glycol di (meth) acrylates can be mentioned. Examples of the polyethylene glycol di (meth) acrylates include triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol (600) di (meth) acrylate. Is exemplified. Examples of the monomer having three (meth) acrylic groups include alkoxylated trimethylolpropane tri (meth) acrylate, glycerol propoxytri (meth) acrylate, pentaerythritol tri (meth) acrylate, and tris (2-hydroxyethyl). ) Isocyanurate tri (meth) acrylate and the like are exemplified. Examples of the alkoxylated trimethylolpropane tri (meth) acrylate include trimethylolpropane tri (meth) acrylate and trimethylolpropane triethoxytri (meth) acrylate. Examples of the monomer having four (meth) acrylic groups include pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate. Examples of the monomer having five (meth) acrylic groups include dipentaerythritol penta (meth) acrylate. Examples of the monomer having six (meth) acrylic groups include ditrimethylolpropane hexa (meth) acrylate. Further, examples of the polyfunctional monomer include diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene.

In the present polymer fine particles, as the polyfunctional monomer used for introducing the crosslinked structure into the core layer, allyl (meth) acrylate is preferable because it is inexpensive and stably supplied. Allyl methacrylate is more preferred.

In one embodiment of the present invention, it is preferable that a crosslinked structure is introduced into the inner layer of the core, but it is preferable that the introduction rate of the crosslinked structure is small. In other words, the inner layer of the core preferably further contains, as a structural unit, a structural unit derived from a polyfunctional monomer and / or a crosslinkable monomer, but the polyfunctional monomer and / or the polyfunctional monomer in the inner layer of the core. / Or the content of the structural unit derived from the crosslinkable monomer is preferably small. The total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the inner layer of the core is 100 of all the structural units derived from the monomer other than the cross-linking agent in the inner layer of the core. It is preferably 10% by weight or less, more preferably 8% by weight or less, and more preferably 5% by weight or less with respect to% by weight. According to this structure, the obtained polymer fine particles have an advantage of being excellent in transparency. The total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the inner layer of the core is 100 of all the structural units derived from the monomer other than the cross-linking agent in the inner layer of the core. It is more preferably 0.1% by weight to 5% by weight, more preferably 0.1% by weight to 3% by weight, and 0.1% by weight to 2.0% by weight with respect to% by weight. It is more preferably 0.1% by weight to 1.5% by weight, more preferably 0.1% by weight to 1.0% by weight, and 0.2% by weight to 0% by weight. It is more preferably 9% by weight, further preferably 0.3% by weight to 0.8% by weight, and particularly preferably 0.4% by weight to 0.6% by weight. According to this structure, the molded product or cured product of the resin composition containing the obtained polymer fine particles has an advantage of being excellent in impact resistance.

In one embodiment of the present invention, it is preferable that a crosslinked structure is introduced in the outer layer of the core, but it is preferable that the introduction rate of the crosslinked structure is small. In other words, the core outer layer preferably further contains, as structural units, a structural unit derived from a polyfunctional monomer and / or a crosslinkable monomer, but the polyfunctional monomer and / or the polyfunctional monomer in the core outer layer. / Or the content of the structural unit derived from the crosslinkable monomer is preferably small. The total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the core outer layer is the cross-linking agent (polyfunctional monomer and cross-linkable single amount) in the core outer layer. It is preferably 10% by weight or less, more preferably 8% by weight or less, and more preferably 5% by weight or less, based on 100% by weight of all the constituent units derived from the monomers other than the body). preferable. According to this structure, the obtained polymer fine particles have an advantage of being excellent in transparency. The total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the core outer layer is the cross-linking agent (polyfunctional monomer and crosslinkable single amount) in the core outer layer. It is more preferably 0.1% by weight to 5% by weight, more preferably 0.1% by weight to 3% by weight, based on 100% by weight of all the constituent units derived from the monomers other than the body). It is preferably 0.1% by weight to 2.0% by weight, more preferably 0.1% by weight to 1.5% by weight, and 0.1% by weight to 1.0% by weight. It is more preferably 0.2% by weight to 0.9% by weight, further preferably 0.3% by weight to 0.8% by weight, and 0.4% by weight to 0% by weight. It is particularly preferably 6% by weight. According to this configuration, the surface of the obtained core layer is soft. Therefore, in the process of producing the polymer fine particles having the blocking inhibitor, for example, in the process of producing the powder or granular material of the polymer fine particles having the blocking inhibitor, the powder or granular materials collide with each other and the powder or granular material and the wall surface of the manufacturing apparatus The anti-blocking agent adhering to the surface of the polymer fine particles (powder / granular material) is less likely to be peeled off due to the collision of the polymer fine particles (powder / granular material). As a result, the obtained polymer fine particles have an advantage that they are more excellent in blocking resistance.

(Glass transition temperature of core layer)
The glass transition temperature of the core layer is preferably 80 ° C. or lower, more preferably 70 ° C. or lower, more preferably 60 ° C. or lower, more preferably 50 ° C. or lower, more preferably 40 ° C. or lower, more preferably 30 ° C. or lower, 20 ° C. or lower. ° C or lower is more preferable, 10 ° C or lower is more preferable, 5 ° C or lower is more preferable, 0 ° C or lower is more preferable, -3 ° C or lower is more preferable, -5 ° C or lower is more preferable, and -7 ° C or lower is particularly preferable. .. In the present specification, the "glass transition temperature" may be referred to as "Tg". According to this structure, polymer fine particles having a low Tg can be obtained. As a result, the obtained resin composition containing the polymer fine particles can provide a molded product or a cured product having excellent toughness.

On the other hand, since it is possible to suppress a decrease in the elastic modulus (rigidity) of the obtained molded product or cured product, that is, a molded product or cured product having a sufficient elastic modulus (rigidity) can be obtained, the Tg of the core layer is , 0 ° C. or higher, more preferably 20 ° C. or higher, further preferably 50 ° C. or higher, particularly preferably 80 ° C. or higher, and most preferably 120 ° C. or higher.

The outer layer of the core preferably has a glass transition temperature of -60 ° C to 30 ° C, more preferably -60 ° C to 0 ° C, more preferably -60 ° C to -20 ° C, and more preferably -60 ° C. It is more preferably about −40 ° C., and particularly preferably −60 ° C. to −50 ° C. According to this configuration, the surface of the obtained core layer is soft. Therefore, in the process of producing the resin composition containing the obtained polymer fine particles and the blocking inhibitor, the resin composition adheres to the surface of the resin composition due to collision of the resin composition and collision of the resin composition with the wall surface of the manufacturing apparatus. There is less peeling of the blocking inhibitor. As a result, the obtained polymer fine particles can provide a resin composition having better blocking resistance.

(Volume average particle size of core layer)
The volume average particle size of the core layer is preferably 0.03 μm to 50.00 μm, more preferably 0.05 μm to 10.00 μm, more preferably 0.08 μm to 2.00 μm, and more preferably 0.09 μm to 1.00 μm. Preferably, 0.09 μm to 0.80 μm is more preferable, 0.09 μm to 0.50 μm is more preferable, 0.10 μm to 0.40 μm is further preferable, and 0.20 μm to 0.30 μm is particularly preferable. When the volume average particle size of the core layer is (a) 0.03 μm or more, a core layer having a desired volume average particle size can be stably obtained, and when (b) 50.00 μm or less, it is obtained. The heat resistance and impact resistance of the molded product or cured product to be obtained are improved. The volume average particle size of the core layer can be measured by using an aqueous latex containing the core layer as a sample and using a dynamic light scattering type particle size distribution measuring device or the like. The method for measuring the volume average particle size of the core layer will be described in detail in the following examples.

(Refractive index of core layer)
The refractive index of the core layer is not particularly limited. The refractive index of the core layer is preferably 1.200 to 1.700, more preferably 1.300 to 1.650, further preferably 1.400 to 1.600, and particularly preferably 1.450 to 1.550.

In the present specification, the refractive index of the core layer is the product obtained by multiplying the refractive index of the inner layer of the core by the weight fraction of the inner layer of the core in the core layer, and (b) the refractive index of the outer layer of the core. It is the sum of the product obtained by multiplying the weight fraction of the core outer layer in the core layer.

The refractive index of the inner layer of the core in the present specification will be described. First, the refractive index of the core inner layer when the core inner layer is composed of one kind of structural unit, in other words, when the core inner layer is made of one kind of monomer used for polymerization of the core inner layer will be described. In this case, in the present specification, the refractive index of the inner layer of the core is (a) the refractive index of the monomer from which the constituent units constituting the inner layer of the core are derived, and (b) the single amount used for the polymerization of the inner layer of the core. It can also be said to be the refractive index of the body. The refractive index of the inner layer of the core when the inner layer of the core is composed of two or more kinds of structural units, in other words, when the inner layer of the core has two or more kinds of monomers used for polymerization of the inner layer of the core will be described. In this case, in the present specification, the refractive index of the inner layer of the core is (a) the refractive index of each monomer from which each structural unit contained in the inner layer of the core is derived, and the respective structural units with respect to all the structural units of the inner layer of the core. It is the sum of the products obtained by multiplying by the weight ratio of (b), and (b) the refractive index of each monomer used for the polymerization of the inner layer of the core with respect to all the monomers used for the polymerization of the inner layer of the core. It can be said that it is the sum of the obtained products by multiplying the usage ratio (% by weight) of each monomer.

In the present specification, the cross-linking agent is excluded from the monomers considered when calculating the refractive index. That is, in the present specification, crosslinkable monomers such as (a) polyfunctional monomers and (b) mercapto group-containing compounds are excluded from the monomers considered when calculating the refractive index. That is, in the present specification, the “total structural unit” in the calculation of the refractive index means all of the structural units derived from the monomer other than the cross-linking agent. Further, in the present specification, "all monomers used for polymerization" in the calculation of the refractive index means all of the monomers used for polymerization other than the cross-linking agent.

Regarding the refractive index of the core outer layer in the present specification, the above-mentioned description regarding the “refractive index of the core inner layer” is incorporated after replacing the “core inner layer” with the “core outer layer”. The method of calculating the refractive index of the core layer will be described in detail in the following examples.

(Hansen solubility parameter δ _{A of the} inner layer of the core and Hansen solubility parameter δ _{B of the} outer layer of the core)
The Hansen solubility parameter δ _{A in the} inner layer of the core is not particularly limited. The Hansen solubility parameter δ _A of the inner layer of the core is preferably 16.0 to 20.0, more preferably 16.5 to 19.5, further preferably 17.0 to 19.0, and 17.5 to 18.5. Especially preferable.

_{The Hansen solubility parameter δ A} of the inner layer of the core in the present specification will be described. _{First, the Hansen solubility parameter δ A} of the core inner layer when the core inner layer is composed of one kind of structural unit, in other words, when the core inner layer is made of one kind of monomer used for polymerization of the core inner layer will be described. In this case, in the present specification, the Hansen solubility parameter δ _A of the core inner layer is (a) the Hansen solubility parameter of the monomer from which the structural unit is derived, and (b) the single amount used for the polymerization of the core inner layer. It can be said that it is the Hansen solubility parameter of the body. _{Next, the Hansen solubility parameter δ A} of the core inner layer will be described when the core inner layer is composed of two or more types of structural units, in other words, when the core inner layer uses two or more types of monomers for polymerization. In this case, in the present specification, the Hansen solubility parameter δ _A of the core inner layer is (a) the Hansen solubility parameter of each monomer from which each structural unit contained in the core inner layer is derived, with respect to all the structural units of the core inner layer. It is the sum of the products obtained by multiplying the weight ratio of each structural unit. (B) The Hansen solubility parameter of each monomer used for the polymerization of the core inner layer is combined with the total unit used for the polymerization of the core inner layer. It can also be said that it is the sum of the obtained products obtained by multiplying the usage ratio (% by weight) of each of the monomers with respect to the dimer.

In the present specification, the polyfunctional monomer and the crosslinkable monomer that function as a crosslinking agent are excluded from the monomers considered when calculating the Hansen solubility parameter. That is, in the present specification, the "total structural unit" in the calculation of the Hansen solubility parameter is derived from the structural unit other than the polyfunctional monomer and the crosslinkable monomer. Intended for all constituent units. Further, in the present specification, the “total monomer used for polymerization” in the calculation of the Hansen solubility parameter is a monomer other than the polyfunctional monomer and a crosslinkable single amount among the monomers used for polymerization. Intended for all monomers other than the body.

The Hansen solubility parameter δ _B of the outer layer of the core is not particularly limited. The Hansen solubility parameter δ _B of the outer layer of the core is preferably 16.0 to 20.0, more preferably 16.5 to 19.5, further preferably 17.0 to 19.0, and 17.5 to 18.5. Especially preferable.

_{Regarding the Hansen solubility parameter δ B} of the core outer layer in the present specification, the above description regarding the “Hansen solubility parameter δ _{A of the} core inner layer” is incorporated after replacing the “core inner layer” with the “core outer layer”. In the following examples, _{the calculation method of the Hansen solubility parameter δ A of the} inner layer of the core and the Hansen solubility parameter δ _B of the outer layer of the core will be described in detail.

(Ratio of core layer)
The ratio of the core layer to the polymer fine particles is preferably 40 to 97% by weight, more preferably 50 to 93% by weight, more preferably 60 to 85% by weight, and 65 to 5% by weight, assuming that the entire polymer fine particles are 100% by weight. 80% by weight is more preferable, and 68 to 76% by weight is particularly preferable. When the ratio of the core layer is 40% by weight or more, the obtained resin composition containing the polymer fine particles can provide a molded product or a cured product having excellent toughness and impact resistance. When the ratio of the core layer is 97% by weight or less, the polymer fine particles do not easily aggregate, so that the resin composition containing the obtained polymer fine particles does not have a high viscosity. As a result, the resin composition can be easy to handle.

(Ratio of core outer layer)
The core layer contains 100% by weight of the core layer, 2% by weight to 20% by weight, preferably 5% by weight to 20% by weight, and more preferably 8% by weight to 20% by weight. It is more preferable to contain 11% by weight to 20% by weight, and particularly preferably 15% by weight to 20% by weight. According to this configuration, the obtained polymer fine particles have the advantage of being more excellent in transparency and blocking resistance.

Each of the inner layer and the outer layer of the core may consist of only one kind of polymer having the same composition of the constituent units. Each of the inner layer of the core or the outer layer of the core may consist of a plurality of types of polymers having different constituent units. In other words, each of the inner layer or the outer layer of the core may contain a complex of a plurality of polymers polymerized separately, or may contain one polymer obtained by polymerizing in order. .. Polymerizing a plurality of polymers in order is also referred to as multi-stage polymerization, and one polymer obtained by multi-stage polymerization is also referred to as multi-stage polymer. In the multistage polymer, each of the plurality of polymers may form a layered structure. A multi-stage polymer in which each of a plurality of polymers forms a layered structure can also be said to be a multilayer polymer. That is, in one embodiment of the present invention, each of the inner layer or the outer layer of the core may contain a complex of a plurality of types of polymers, a multistage polymer and / or a multilayer polymer.

(2-2. Shell layer)
The shell layer is a layer composed of a polymer grafted to the core layer. The shell layer preferably covers at least a part of the core outer layer and preferably covers the entire circumference of the core outer layer. In the present polymer fine particles, it is particularly preferable that the core outer layer covers the entire circumference of the core inner layer and the shell layer covers the entire circumference of the core outer layer. According to this structure, there is an advantage that the dispersibility of the polymer fine particles in the matrix resin is improved.

Hereinafter, each aspect of the shell layer will be described, but the description of (2-1. Core layer) is appropriately incorporated except for the matters described in detail below.

The composition of the shell layer is not particularly limited. The shell layer contains, as a structural unit, a structural unit derived from one or more kinds of monomers selected from the group consisting of aromatic vinyl monomer, vinyl cyanide monomer, and (meth) acrylate monomer. It preferably contains a polymer. According to this configuration, the resulting shell layer can play a role in the polymer fine particles, for example, (a) to (c) below: (a) Compatibility between the matrix resin and the polymer fine particles. To improve, (b) to improve the dispersibility of the polymer fine particles in the matrix resin, and (c) the polymer fine particles are primary in the resin composition containing the obtained polymer fine particles or in the molded product or cured product. To be able to disperse in the form of particles. The above description is incorporated for specific examples of each of the aromatic vinyl monomer, vinyl cyanide monomer, and (meth) acrylate monomer.

The shell layer preferably contains (i) a structural unit (unit a) derived from an alkyl acrylate and (ii) a structural unit (unit b) derived from an aromatic vinyl compound as a structural unit. The shell layer is a structural unit (unit c) derived from a vinyl compound other than the alkyl acrylate and the aromatic vinyl compound, which can be optionally copolymerized with an alkyl acrylate and / or an aromatic vinyl compound as a structural unit. May be further contained. Examples of the unit c include a (meth) acrylate-based monomer other than the alkyl acrylate and / or a structural unit derived from the vinyl-based monomer A other than the aromatic vinyl compound. When the shell layer contains the unit a, the unit b, and optionally the unit c as the constituent units, the obtained polymer fine particles have an advantage that they are more excellent in blocking resistance.

In the shell layer, the unit a is a structural unit derived from one or more alkyl acrylates selected from the group consisting of methyl methacrylate and butyl acrylate because the unit a is inexpensive and stably supplied. It is more preferable that the structural unit is derived from methyl methacrylate and the structural unit is derived from butyl acrylate.

In the shell layer, the unit b is preferably styrene because it has high thermal stability, is inexpensive, and is stably supplied.

The shell layer is composed of (i) unit a85% by weight to 97% by weight, unit b3% by weight to 15% by weight, and unit c0% by weight in a total of 100% by weight of unit a, unit b, and unit c. It is preferable to have ~ 12% by weight, and (ii) it is more preferable to have a unit a86% by weight to 96% by weight, a unit b4% by weight to 14% by weight, and a unit c0% by weight to 8% by weight. (Iii) It is more preferable to have a unit a88% by weight to 94% by weight, a unit b6% by weight to 12% by weight, and a unit c0% by weight to 4% by weight, and (iv) a unit a90% by weight to 92% by weight. It is particularly preferable to have the unit b8% by weight to 10% by weight. Since the present polymer fine particles contain a core outer layer having a specific constitution, even if the shell layer contains the unit b in the above-mentioned range, the possibility that the shell layer enters the core layer is small. As a result, the obtained polymer fine particles have an advantage that they are further excellent in blocking resistance.

The shell layer preferably contains, as a structural unit, a structural unit derived from a monomer having a reactive group. The monomer having a reactive group includes an epoxy group, an oxetane group, a hydroxyl group, an amino group, an imide group, a carboxylic acid group, a carboxylic acid anhydride group, a cyclic ester, a cyclic amide, a benzoxazine group, and a cyanate ester group. It is preferable that the monomer has one or more reactive groups selected from the group consisting of, and has one or more reactive groups selected from the group consisting of an epoxy group, a hydroxyl group, and a carboxylic acid group. It is more preferably a monomer. According to the above configuration, the shell layer of the polymer fine particles and the matrix resin can be chemically bonded in the obtained resin composition containing the polymer fine particles. As a result, it is possible to maintain a good dispersed state of the polymer fine particles in the resin composition containing the obtained polymer fine particles or in the molded product or the cured product without aggregating the polymer fine particles.

In one embodiment of the present invention, a crosslinked structure may be introduced into the shell layer. In one embodiment of the present invention, it is preferable that the shell layer does not have a crosslinked structure because the dispersibility of the polymer fine particles in the matrix resin is good.

(Glass transition temperature of shell layer)
The higher the glass transition temperature of the shell layer, the more preferable, 0 ° C. or higher, 30 ° C. or higher, more preferably 50 ° C. or higher, 70 ° C. or higher, more preferably 90 ° C. or higher, 95 ° C. or higher. Further preferably, it is particularly preferably 100 ° C. or higher.

The shell layer may consist of only one type of polymer having the same composition of constituent units. The shell layer may consist of a plurality of types of polymers having different constituent units. In other words, the shell layer may contain a complex of a plurality of polymers individually polymerized, or may contain a multi-stage polymer. The multi-stage polymer of the shell layer may be a multi-layer polymer. That is, in one embodiment of the present invention, the shell layer may contain a complex of a plurality of types of polymers, a multistage polymer and / or a multilayer polymer.

(Refractive index of shell layer)
The refractive index of the shell layer is not particularly limited. The refractive index of the shell layer is preferably 1.200 to 1.700, more preferably 1.300 to 1.650, further preferably 1.400 to 1.600, and particularly preferably 1.450 to 1.550.

Regarding the refractive index of the shell layer in the present specification, the above-mentioned description regarding the “refractive index of the core inner layer” is incorporated after replacing the “core inner layer” with the “shell layer”. The method of calculating the refractive index of the shell layer will be described in detail in the following examples.

The absolute value of the difference between the refractive index of the core layer and the refractive index of the shell layer is preferably as small as possible, and is preferably 0 or more and less than 0.003, for example. According to this configuration, the obtained polymer fine particles have an advantage of being more transparent.

In the present specification, "refractive index of core inner layer", "refractive index of core outer layer", "refractive index of core layer", "refractive index of shell layer" and "refractive index of core layer and refractive index of shell layer" Each of the "absolute values of the difference between" may be a value obtained by rounding off the fourth digit after the decimal point.

(Hansen solubility parameter δ _{C of} shell layer)
The Hansen solubility parameter δ _C of the shell layer is not particularly limited. The Hansen solubility parameter δ _C of the shell layer is preferably 16.0 to 20.0, more preferably 16.5 to 19.5, further preferably 17.0 to 19.0, and 17.5 to 18.5. Especially preferable.

_{Regarding δ C} , which is the Hansen solubility parameter of the shell layer in the present specification _{, the above-mentioned description regarding “δ A,} which is the Hansen solubility parameter of the core inner layer” is replaced with “shell layer” after replacing “core inner layer” with “shell layer”. Invite. _{In the following examples, the calculation method of δ C} , which is the Hansen solubility parameter of the shell layer, will be described in detail.

The polymer fine particles _{preferably satisfy 0.4 ≦ | δ A −} δ _B |, and more preferably 0.5 ≦ | δ _{A −} δ _B |. According to this configuration, the obtained polymer fine particles have an advantage of being more excellent in blocking resistance. The polymer fine particles _{preferably satisfy 0.4 ≦ | δ B −} δ _C |, and more preferably 0.5 ≦ | δ _{B −} δ _C |. According to this configuration, the obtained polymer fine particles have an advantage of being more excellent in blocking resistance. The polymer fine particles more preferably satisfy _{0.4 ≦ | δ A −} δ _B |, 0.4 ≦ | δ _{B −} δ _C | and 0.1 ≧ | δ _{A −} δ _{C |.} It is particularly preferable to satisfy 5 ≦ | δ _{A −} δ _B |, 0.5 ≦ | δ _{B −} δ _C | and 0.1 ≧ | δ _{A −} δ _{C |.} According to this structure, the obtained polymer fine particles have an advantage that they are further excellent in blocking resistance.

(2-4. Blocking inhibitor)
The polymer fine particles preferably further contain a blocking inhibitor. It is more preferable to contain a blocking inhibitor on the surface of the polymer fine particles, and it is further preferable to contain a blocking inhibitor on the surface of the aggregate (for example, powder or granular material) of the polymer fine particles. According to this structure, the obtained polymer fine particles can provide a resin composition having (a) excellent blocking resistance and (b) uniformly dispersed polymer fine particles in a matrix resin.

The blocking inhibitor is not particularly limited as long as it exhibits the effect of one embodiment of the present invention. Anti-blocking agents include silicon dioxide, titanium oxide, aluminum oxide, zirconium oxide, aluminum silicate, diatomaceous earth, zeolite, kaolin, talc, calcium carbonate, calcium phosphate, barium sulfate, magnesium hydrosilicate and other inorganic fine particles. ; Anti-blocking agent composed of organic fine particles; Examples thereof include fat-based anti-blocking agents such as polyethylene wax, higher fatty acid amide, metal silicate, and silicone oil. Among these, a blocking inhibitor composed of inorganic fine particles and a blocking inhibitor composed of organic fine particles are preferable, and a blocking inhibitor composed of organic fine particles is more preferable. As the blocking inhibitor composed of organic fine particles, a blocking inhibitor composed of organic fine particles of a polymer containing one or more monomer units selected from an aromatic vinyl monomer, a vinyl cyan monomer, and a (meth) acrylate monomer is particularly preferable. preferable.

The blocking inhibitor composed of inorganic fine particles or organic fine particles is generally one in which the inorganic fine particles or organic fine particles are dispersed in a liquid, or a colloidal one. The blocking inhibitor composed of inorganic fine particles or organic fine particles has a volume average particle diameter (Mv) of usually 10 μm or less, preferably 0.01 μm to 10.00 μm, more preferably 0.03 μm to 5.00 μm, and 0. It is more preferably 05 μm to 1.00 μm, further preferably 0.07 μm to 0.50 μm, and particularly preferably 0.08 μm to 0.35 μm. According to this configuration, since the number of particles of the blocking inhibitor per unit weight is large, the number of blocking inhibitors adhering to the surface of the aggregate (for example, powder or granular material) of the polymer fine particles increases. As a result, there is an advantage that the coating effect of the blocking inhibitor on the surface of the aggregate of the polymer fine particles is increased and the blocking preventing effect is increased.

The glass transition temperature of the blocking inhibitor is preferably higher than the temperature of the storage environment of the polymer fine particles (for example, powder or granular material), for example, 50 ° C to 160 ° C, more preferably 60 ° C to 150 ° C, and 70 ° C. ~ 140 ° C. is more preferable, and 80 ° C. to 130 ° C. is particularly preferable. According to this configuration, there is an advantage that the blocking prevention effect is increased.

The content of the blocking inhibitor in the polymer fine particles is preferably 0.01% by weight to 5.00% by weight, preferably 0.50% by weight to 3.0% by weight, based on the total weight (100% by weight) of the polymer fine particles. 00% by weight is more preferable.

(2-5. Other optional ingredients)
The present polymer fine particles may contain other optional components other than the above-mentioned components, if necessary. Examples of other optional components include various components described in the section (3-3. Other additives) described later.

The blocking inhibitor and other optional components can be appropriately added in any step in the method for producing the present polymer fine particles. For example, the blocking inhibitor and other optional components can be appropriately added in the process of producing the powder or granular material of the polymer fine particles. For example, the polymer fine particles can be added to an aqueous suspension (aqueous latex) before or after agglutination. The anti-blocking agent and other optional ingredients can also be added directly to the polymer microparticles or the particulates of the polymer microparticles.

(2-1-4. Physical characteristics of polymer fine particles)
Hereinafter, the physical characteristics of the polymer fine particles will be described.

(Volume average particle size (Mv) of polymer fine particles)
The volume average particle diameter (Mv) of the polymer fine particles is preferably 0.03 μm to 50.00 μm, preferably 0.05 μm to 10 μm, because a resin composition having a desired viscosity and a highly stable resin composition can be obtained. .00 μm is more preferable, 0.08 μm to 2.00 μm is more preferable, 0.09 μm to 1.00 μm is more preferable, 0.09 μm to 0.80 μm is more preferable, and 0.09 μm to 0.50 μm is more preferable. 0.09 μm to 0.23 μm is more preferable, and 0.10 μm to 0.23 μm is particularly preferable. Further, when the volume average particle size (Mv) of the polymer fine particles is within the above range, there is an advantage that the dispersibility of the polymer fine particles in the matrix resin is improved. Further, the larger the volume average particle size (Mv) of the polymer fine particles, the smaller the cohesive force of the polymer fine particles. In the present specification, the "volume average particle size (Mv) of the polymer fine particles" is intended to be the volume average particle size of the primary particles of the polymer fine particles, unless otherwise specified. The volume average particle size of the polymer fine particles can be measured by using an aqueous latex containing the polymer fine particles as a sample and using a dynamic light scattering type particle size distribution measuring device or the like. The method for measuring the volume average particle size of the polymer fine particles will be described in detail in the following Examples. The volume average particle size of the polymer fine particles shall be measured by cutting the cured product or molded body of the resin composition, imaging the cut surface using an electron microscope or the like, and using the obtained imaging data (imaging image). You can also.

The number distribution of the volume average particle size of the polymer fine particles in the matrix resin has a half price range of 0.5 times or more and 1 time or less of the volume average particle size because a resin composition having low viscosity and easy to handle can be obtained. Is preferable.

(Refractive index of polymer fine particles)
The refractive index of the polymer fine particles is not particularly limited. The refractive index of the polymer fine particles is preferably 1.200 to 1.700, more preferably 1.300 to 1.650, further preferably 1.400 to 1.600, and particularly preferably 1.450 to 1.550. ..

In the present specification, the refractive index of the polymer fine particles is the product obtained by multiplying the refractive index of the core layer by the weight fraction of the core layer in the polymer fine particles, and (b) the refractive index of the shell layer. Is the sum of the product obtained by multiplying the weight fraction of the shell layer in the polymer fine particles.

(2-3. Method for producing polymer fine particles)
The present polymer fine particles can be produced by a known method, for example, an emulsion polymerization method, a suspension polymerization method, a microsuspension polymerization method, or the like. Specifically, the core inner layer can be produced by polymerizing the monomer forming the core inner layer. Further, by polymerizing the monomer forming the core outer layer in the presence of the obtained core inner layer, the core inner layer which is the innermost layer and the core outer layer formed so as to cover at least a part of the core inner layer A core layer having the above can be produced. Further, a polymer having a core layer and a shell layer formed so as to cover at least a part of the core layer by polymerizing the monomer forming the shell layer in the presence of the obtained core layer. Fine particles can be produced.

The polymerization of the inner layer of the core, the polymerization of the outer layer of the core, and the polymerization of the shell layer in the present polymer fine particles can be produced by known methods such as an emulsion polymerization method, a suspension polymerization method, and a microsuspension polymerization method. The emulsion polymerization method is preferable as the method for producing the present polymer fine particles, in other words, the polymerization of the inner layer of the core, the polymerization of the outer layer of the core, and the polymerization of the shell layer in the present polymer fine particles. According to this configuration, (a) the composition design of the polymer fine particles is easy, (b) industrial production is easy, and (c) the polymer fine particles that can be suitably used for the production of the present resin composition described later. It has the advantage that the aqueous latex of the above can be easily obtained.

When the emulsion polymerization method is adopted as the method for producing the present polymer fine particles, a known emulsifier (dispersant), a pyrolysis type initiator and / or a redox type initiator may be used for the production of the present polymer fine particles. it can. Examples of the pyrolytic initiator include known initiators such as 2,2'-azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, and ammonium persulfate. Redox-type initiators include (a) peroxides such as organic peroxides and inorganic peroxides, and (b) reducing agents such as sodium formaldehyde sulfoxylate and glucose as needed, and sulfuric acid as needed. It is an initiator in which a transition metal salt such as iron (II), a chelating agent such as disodium ethylenediamine tetraacetate if necessary, and a phosphorus-containing compound such as sodium pyrophosphate as necessary are used in combination. Organic peroxides include t-butyl peroxyisopropyl carbonate, paramentan hydroperoxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, and t-hexyl. Examples include peroxide. Examples of the inorganic peroxide include hydrogen peroxide, potassium persulfate, and ammonium persulfate.

When a polyfunctional monomer is used as a cross-linking agent in the polymerization of the core inner layer, the core outer layer and / or the shell layer for the purpose of introducing a cross-linked structure into the core inner layer, the core outer layer and / or the shell layer, the polymerization In, a known chain transfer agent can be used within a known usage amount range. By using a chain transfer agent in the polymerization of the core inner layer, the core outer layer and / or the shell layer, the molecular weight and / or the degree of cross-linking of the obtained core inner layer, the core outer layer and / or the shell layer can be easily adjusted. ..

In addition to the above-mentioned components, a surfactant can be further used in the production of the present polymer fine particles. The types and amounts of the surfactants used are in the known range.

In the production of the present polymer fine particles, conditions such as polymerization temperature, pressure, and deoxidation in the polymerization can be applied within a known range.

By being produced by the production method having the above-described embodiment, the present polymer fine particles can be obtained as an aqueous latex containing the polymer fine particles. By physically and / or chemically treating the aqueous latex containing the polymer fine particles, an agglomerate of the polymer fine particles (for example, a powder or granular material) can be obtained from the aqueous latex. The powder or granular material of the present polymer fine particles is also an embodiment of the present invention.

The physical processing is not particularly limited. By physically treating the aqueous latex containing the polymer fine particles, for example, by spray drying and freeze-drying, powders and granules of the polymer fine particles can be obtained from the aqueous latex.

Examples of the chemical treatment include addition of a coagulant to an aqueous latex containing polymer fine particles. Examples of the coagulant include salts such as calcium chloride and magnesium chloride, and acids such as hydrochloric acid and sulfuric acid. By adding a coagulant to the aqueous latex containing the polymer fine particles, the polymer fine particles in the aqueous latex can be agglomerated, and a slurry containing the agglomerates of the polymer fine particles can be obtained. In addition to adding a coagulant to the aqueous latex containing the polymer fine particles, the aqueous latex may be heat treated. By separating the aqueous phase from the slurry containing the agglomerates of the polymer fine particles, the agglomerates of the polymer fine particles can be obtained. The aggregate of the obtained polymer fine particles may be washed and / or dried. As described above, a powder or granular material of polymer fine particles can be obtained by adding a coagulant, heating, washing and drying.

In the present specification, the “powder / granular material” means an aggregate containing both powder and granules, and a collection of powders, granules, and the like. Further, when particularly distinguished, "powder" means one having a volume average particle diameter of 0.01 mm to 0.1 mm, and "granular material" means one having a volume average particle diameter of 0.1 mm to 10 mm. However, the powder or granular material may contain coarse particles of 10 mm or more. The "volume average particle size" in the range of less than 10 μm can be measured using a dynamic light scattering (DLS) particle size distribution measuring device Nanotrac WaveII-EX150 (manufactured by Microtrac Bell Co., Ltd.), and the “volume average particle size” in the range of 10 μm or more can be measured. The "volume average particle size" can be measured using a laser diffraction type particle size distribution measuring device Microtrac MT3000II (manufactured by Microtrac Bell Co., Ltd.). In the present specification, the powder or granular material of the polymer fine particles may be an aggregate of the primary particles of the polymer fine particles, in other words, the secondary particles of the polymer fine particles.

[3. Resin composition]
The resin composition according to one embodiment of the present invention is described in [2. The polymer fine particles described in [Polymer fine particles] and the matrix resin are contained, and the absolute value of the difference between the refractive index of the polymer fine particles and the refractive index of the matrix resin is 0 to 0.003.

The "resin composition according to one embodiment of the present invention" may be hereinafter referred to as "the present resin composition". When the present resin composition contains a thermoplastic resin as a matrix resin, a molded product can be produced by molding the resin composition. When the present resin composition contains a thermosetting resin as a matrix resin, a cured product can be produced by curing the resin composition.

Since the present resin composition has the above-mentioned structure, it is possible to provide a molded product or a cured product having excellent transparency. Further, since the present resin composition has the above-mentioned structure, the polymer fine particles are uniformly dispersed in the matrix resin. Therefore, the present resin composition can provide a molded product having excellent mechanical properties (for example, toughness and elasticity) derived from the polymer fine particles.

(3-1. Matrix resin)
The matrix resin is not particularly limited. The matrix resin may be, for example, a thermosetting resin, a thermoplastic resin, or a combination of any thermosetting resin and any thermoplastic resin.

The thermosetting resin in the matrix resin is not particularly limited. Examples of the thermosetting resin in the matrix resin include a resin containing a polymer obtained by polymerizing an ethylenically unsaturated monomer, a resin containing a polymer obtained by polymerizing an aromatic polyester raw material, an epoxy resin, and a phenol resin. , Polypolymer resin, amino-formaldehyde resin and the like. Only one type of these thermosetting resins may be used, or two or more types may be used in combination.

The thermoplastic resin in the matrix resin is not particularly limited. Examples of the thermoplastic resin in the matrix resin include acrylic polymers, vinyl copolymers, polycarbonates, polyamides, polyesters, polyphenylene ethers, polyurethanes and polyvinyl acetates. Only one type of these thermoplastic resins may be used, or two or more types may be used in combination.

In this resin composition, the absolute value of the difference between the refractive index of the polymer fine particles and the refractive index of the matrix resin is 0 to 0.003, and the molded or cured product of the obtained resin composition is transparent. Therefore, it is preferable that the absolute value of the difference is small. The absolute value of the difference between the refractive index of the polymer fine particles and the refractive index of the matrix resin is preferably 0 to 0.003, more preferably 0 to 0.002, and 0 to 0.001. It is more preferably 0 or more and less than 0.001.

(3-2. Antioxidant)
The present resin composition may contain an antioxidant as long as the effect according to the embodiment of the present invention is not impaired. Examples of the antioxidant include known hindered phenol-based antioxidants and hindered amine-based antioxidants.

(3-3. Other additives)
The present resin composition may further contain other additives other than the above-mentioned components, if necessary. Other additives may include other additives such as dyes, pigments, stabilizers, antioxidants, reinforcing agents, fillers, flame retardants, foaming agents, lubricants and plasticizers. In other words, the above-mentioned other additives may be added to the resin composition, if necessary.

(3-4. Method for producing resin composition)
The method for producing the present resin composition is not particularly limited. For example, the present resin is obtained by mixing the polymer fine particles according to one embodiment of the present invention, a matrix resin, and if necessary, an antioxidant and / or other additives, and melt-kneading the obtained mixture. The composition can be obtained.

In the method for producing the present resin composition, a Henschel mixer, a tumbler mixer and the like can be used for mixing the raw materials, and a single-screw or twin-screw extruder, a Banbury mixer, a pressure kneader and the like can be used for melt-kneading the obtained mixture. A kneading machine such as a mixing roll can be used.

(3-5. Applications)
The use of the polymer fine particles and the resin composition is not particularly limited. The polymer fine particles and the resin composition can be suitably used for optical applications in which impact resistance is particularly required. For example, the molded product or cured product of the present resin composition can be suitably used for the interior / exterior of automobiles, the interior / exterior of personal computers, the interior / exterior of mobile phones or smartphones, the interior / exterior of solar cells, and the like. The molded product or cured product of this resin composition is (a) a photographing lens for a camera, a photographing lens for a VTR, a photographing lens for a projector, a finder, a filter, a prism, a frennel lens, and the like; Pickup lenses for optical disks in players, DVD players, MD players, etc., lenses for general cameras, lenses for video cameras, objective lenses for laser pickups, diffraction grids, holograms, and collimeter lenses, fθ lenses for laser printers, cylindrical lenses, etc. Lens fields such as condenser lenses for liquid crystal projectors, projection lenses for liquid crystal projectors, Frenel lenses, lenses for eyeglasses; (c) optical recording fields for optical disks such as CDs, DVDs, MDs; (d) optical waveguides, prisms, etc. Optical communication fields such as optical fibers, optical switches and optical connectors; (e) Vehicle fields such as automobile headlights, tail lamp lenses, inner lenses, instrument covers and sun roofs; (f) Eyeglasses, contact lenses, lenses for endoscopes, etc. Medical equipment fields such as medical supplies that require sterilization; and (g) road signs, bathroom equipment, flooring materials, road translucent plates, lenses for paired glasses, light-collecting windows, carports, lighting lenses, lighting covers, building materials It can also be suitably used in the fields of construction and building materials such as sizing for lenses. The molded body or cured product of this resin composition is (a) a liquid crystal display member such as a light guide plate or a diffuser plate for a liquid crystal; (b) a screen for a projector; (c) a display-related member such as a head-up display (for example, front). It can be used for (face plate); (d) containers for microwave cooking (for example, tableware); (e) housings for home appliances; (f) toys; (g) sunglasses; and (h) stationery.

Hereinafter, one embodiment of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. One embodiment of the present invention can be appropriately modified and implemented to the extent that it can be adapted to the above-mentioned or later gist, and any of these modified embodiments is included in the technical scope of the present invention. ..

<Measurement method>
First, the measurement methods in Examples and Comparative Examples will be described below.

(Polymer fine particles and refractive index of each layer)
The refractive index of each of the inner core layer, the outer core layer, and the shell layer was calculated as follows. First, the refractive index of each monomer used in the polymerization of each layer was multiplied by the ratio (% by weight) of each monomer used to all the monomers used in the polymerization of each layer. Next, the obtained products were added up to calculate the refractive index of each layer. Specifically, it was calculated based on the following equation 1. Here, the refractive index of methyl methacrylate (hereinafter referred to as MMA) is 1.4900, the refractive index of butyl acrylate (hereinafter referred to as BA) is 1.4631, and the refractive index of styrene (hereinafter referred to as ST) is 1.591. did. In the formula 1, the usage ratio (% by weight) of each monomer was defined as the weight fraction (% by weight) of each monomer with respect to the total monomer (100% weight) used for the polymerization of each layer.
(Equation 1)
Refractive index of each layer = (refractive index of MMA x ratio of MMA used) + (refractive index of BA x ratio of used BA) + (refractive index of ST x ratio of ST used).

Further, using the obtained refractive index of the inner layer of the core and the refractive index of the outer layer of the core, the refractive index of the core layer was calculated based on the following formula 2. The weight fraction (% by weight) of the core inner layer and the core outer layer was defined as the weight fraction (weight%) of each of the core inner layer and the core outer layer with respect to the entire core layer (100% by weight).
(Equation 2)
Refractive index of core layer = (refractive index of core inner layer x weight fraction of core inner layer) + (refractive index of core outer layer x weight fraction of core outer layer).

Further, using the obtained refractive index of the core layer and the refractive index of the outer layer of the shell, the refractive index of the polymer fine particles was calculated based on the following formula 3. The weight fraction (% by weight) of the core layer and the outer layer of the shell was defined as the weight fraction (% by weight) of each of the core layer and the shell layer with respect to the polymer fine particles (100% by weight).
(Equation 2)
Refractive index of core layer = (refractive index of core inner layer x weight fraction of core inner layer) + (refractive index of core outer layer x weight fraction of core outer layer).

(Hansen solubility parameter of each layer)
_{The Hansen solubility parameters (δ A} , δ _B and δ _C ) of each of the core inner layer, core outer layer and shell layer were calculated as follows. First, the Hansen solubility parameter of each monomer used during the polymerization of each layer was multiplied by the usage ratio (% by weight) of each monomer with respect to all the monomers used for the polymerization of each layer. Next, the obtained products were added up to calculate _{the Hansen solubility parameter (δ A} , δ _B and δ _{C) of each layer.} Specifically, it was calculated based on the following equation 3. Here, the Hansen solubility parameter of MMA was set to 17.9, the Hansen solubility parameter of BA was set to 17.5, and the Hansen solubility parameter of ST was set to 19.1. In the formula 3, the usage ratio (% by weight) of each monomer was defined as the weight fraction (% by weight) of each monomer with respect to all the monomers (100% by weight) used for the polymerization of each layer.
(Equation 3)
Hansen solubility parameter of each layer = (Hansen solubility parameter of MMA × usage ratio of MMA) + (Hansen solubility parameter of BA × usage ratio of BA) + (Hansen solubility parameter of ST × usage ratio of ST).

(Polymerization conversion rate)
After the polymerization of each layer, a part of the obtained aqueous latex was collected and used as a sample, and the weight of the sample was precisely weighed. The sample was left in a hot air dryer at 120 ° C. for 1 hour to dry. The weight of the sample after drying was precisely weighed as the solid content. Next, the ratio of the weight of the sample before and after drying was determined as the ratio of solid components in the aqueous latex. Finally, using this solid component ratio, the polymerization conversion rate was calculated by the following formula 4. In the following formula 4, the "prepared monomer" does not contain a polyfunctional monomer and a crosslinkable monomer, and the "prepared monomer" is a polyfunctional among the used monomers. The amount of monomer other than the sex monomer and the crosslinkable monomer.
(Equation 4)
Polymerization conversion rate = (total weight of charged raw materials x solid component ratio-total weight of raw materials other than monomer) / weight of charged monomer x 100 (%)
(Volume average particle size of polymer fine particles)
The volume average particle size of the polymer fine particles was measured using the aqueous latex of the polymer fine particles after the shell layer was formed. As a measuring device, MICROTRAC UPA150 manufactured by Nikkiso Co., Ltd. was used.

(Preparation of powders of polymer fine particles)
For the evaluation of the transparency and blocking resistance of the polymer fine particles and the breakage test of the polymer fine particles, the polymer fine particles were used. A method for preparing powders of polymer fine particles from the aqueous latex containing the polymer fine particles obtained in each Example and Comparative Example will be described below.

First, an aqueous calcium chloride solution containing calcium chloride at a concentration of 25% by weight was prepared. Next, a mixed solution of 400 parts by weight of deionized water and 3.6 parts by weight of an aqueous calcium chloride solution was prepared, and the temperature of the mixed solution was raised to 70 ° C. Subsequently, 100 parts by weight of the aqueous latex containing the polymer fine particles obtained in each Example and Comparative Example was added to the mixed solution at 70 ° C. By such an operation, a slurry containing agglomerates of polymer fine particles was obtained. Then, 1.5 parts by weight of an acrylic blocking inhibitor was added to the obtained slurry. The temperature of the obtained reaction solution was raised to 95 ° C. Subsequently, agglomerates of polymer fine particles were obtained by dehydration from the slurry, and the obtained agglomerates were dried to obtain powdery particles of polymer fine particles.

(Blocking resistance of polymer fine particles)
The blocking resistance of the polymer fine particles was evaluated by measuring the adhesive force of the polymer fine particles. It can be said that the smaller the adhesive force of the polymer fine particles, the better the blocking resistance. The adhesive force of the polymer fine particles was measured as follows. The obtained polymer fine particles were sieved using a sieve having an opening of 1 μm. Then, 30 g of the sieved powder or granular material was housed in a bottomed metal tubular container having a diameter of 50 mm. Next, a weight stone (diameter 48 mm, 6.3 kg) was placed on the powder or granular material contained in the metal tubular container, and the metal tubular container was allowed to stand in an oven at 60 ° C. for 2 hours. Then, the metal tubular container was taken out from the oven and allowed to stand at room temperature for 1 hour. Then, the weight stone was removed from the powder or granular material in the metal tubular container, and the powder or granular material was taken out from the container. By such an operation, a mass of columnar polymer fine particles was obtained. A stress was applied vertically to the side surface (arc side) of the obtained polymer fine particle mass using a rheometer to disintegrate the polymer fine particle mass. The adhesive force of the polymer fine particles was measured by measuring the stress when the polymer fine particles collapsed. The adhesive force of the polymer fine particles was defined as the minimum pressure value required to disintegrate the polymer fine particle mass. The results are shown in Tables 2 and 3.

(Break test of polymer fine particles)
The obtained polymer fine particles were sieved using a sieve having an opening of 1 μm. Then, 50 g of the sieved powder or granular material and 10 iron balls having a diameter of 5 mm were placed in a plastic container having a volume of 500 mL, and the plastic container was sealed. Then, the plastic container was shaken for 2 hours using a shaker (manufactured by Yamato Scientific Co., Ltd .: SA31). Here, the shaker speed was set to the MAX value of the dial. Then, the powder or granular material and the iron ball were taken out from the plastic container, and the iron ball was removed to obtain only the powder or granular material. Then, using the obtained powder or granular material, the adhesive force of the polymer fine particles was measured by the same method as described above. The results are shown in Tables 2 and 3.

(Transparency of polymer fine particles)
The transparency of the polymer fine particles was evaluated by measuring the Haze value of the molded product of the polymer fine particles. It can be said that the smaller the Haze value of the polymer fine particles, the more excellent the transparency. The Haze value of the polymer fine particles was measured as follows. The obtained powder or granular material of the polymer fine particles was subjected to a roll molding machine and kneaded at 160 ° C. for 5 minutes to obtain a sheet-shaped molded product. A plurality of the obtained sheet-shaped compacts were stacked and applied to a press machine, and pressed at 170 ° C. for 15 minutes to obtain a molded product having a thickness of 2 mm. The Haze value of this molded product was measured. The results are shown in Tables 2 and 3.

Next, each manufacturing method, each Example, and each Comparative Example will be described below.

<Preparation of polymer fine particles>
The usage ratio (% by weight) of each monomer used in the production of the polymer fine particles of each Example and Comparative Example is as shown in Tables 1 and 3. The weight ratios of the core inner layer, the core outer layer, and the shell layer in the polymer fine particles of each Example and Comparative Example are as shown in Tables 1 and 3. In the production of the polymer fine particles of each Example and Comparative Example, the amount of the emulsifier used was changed according to the composition of the monomer used in order to make the obtained polymer fine particles have the same particle size.

[Examples 1 to 5 and Comparative Examples 1 to 3: Preparation of aqueous latex containing polymer fine particles]
(Example 1)
175 parts by weight of deionized water, 0.473 parts by weight of boric acid, 0.0473 parts by weight of sodium carbonate and polyoxyethylene lauryl ether phosphoric acid (Toho Kagaku) in a pressure-resistant polymerizer equipped with a stirrer and having a volume of 8 L. Manufactured by Kogyo Co., Ltd., trade name: Phosphanol RD-510Y) 0.0155 parts by weight was charged. Here, polyoxyethylene lauryl ether phosphoric acid became sodium polyoxyethylene lauryl ether phosphate in the presence of sodium carbonate, and functioned as an emulsifier.

Next, oxygen was sufficiently removed from the inside of the pressure-resistant polymerizer by replacing the gas inside the pressure-resistant polymerizer with nitrogen while stirring the charged raw materials, so that the inside of the pressure-resistant polymerizer was substantially free of oxygen. After that, the temperature inside the pressure-resistant polymerizer was raised to 80 ° C. Then, (a) 0.684 parts by weight of MMA, 4.34 parts by weight and ST1.976 parts by weight of MMA as a monomer other than the cross-linking agent, and (b) 0.035 allyl methacrylate which is a polyfunctional monomer as a cross-linking agent. A mixture consisting of parts by weight and (c) 0.035 parts by weight of cumene hydroperoxide was added into the pressure-resistant polymerizer. Next, disodium ethylenediaminetetraacetate (hereinafter referred to as EDTA) and ferrous sulfate were dissolved in deionized water to contain EDTA at a concentration of 0.08% by weight, and ferrous sulfate was 0.02% by weight. An EDTA / ferrous sulfate mixture containing% was prepared. In addition, a sodium formaldehyde sulfoxylate solution containing sodium formaldehyde sulfoxylate at a concentration of 5% by weight was prepared. Next, 0.07 parts by weight of the EDTA / ferrous sulfate mixture and 0.0645 parts by weight of the formaldehyde sulfoxylate sodium solution were added into the pressure-resistant polymerizer. Subsequently, after stirring the reaction solution in the pressure-resistant polymerizer for 15 minutes, 0.0583 parts by weight of cumene hydroperoxide was added into the pressure-resistant polymerizer. Then, the reaction solution in the pressure-resistant polymerizer was stirred for another 15 minutes. Seed particles were obtained by such an operation. The polymerization conversion rate was 93.2%.

Next, the temperature inside the pressure-resistant polymerizer was set to 60 ° C. Subsequently, an aqueous sodium hydroxide solution containing sodium hydroxide at a concentration of 2% by weight was prepared. Next, 0.023 parts by weight of a sodium formaldehyde sulfoxylate solution, 0.0175 parts by weight of cumene hydroperoxide, and 0.042 parts by weight of an aqueous sodium hydroxide solution were added into the pressure-resistant polymerizer. Subsequently, (a) 5.868 parts by weight of MMA, 37.194 parts by weight of BA and 16.938 parts by weight of ST as a monomer other than the cross-linking agent, and (b) allyl methacrylate, which is a polyfunctional monomer as the cross-linking agent, 0. A mixture consisting of 3 parts by weight and (c) 0.363 parts by weight of polyoxyethylene lauryl ether phosphoric acid was added into the pressure-resistant polymerizer over 180 minutes. During the addition of the mixture, 0.069 parts by weight of a sodium formaldehyde sulfoxylate solution and 0.105 parts by weight of cumene hydroperoxide were intermittently added into the pressure-resistant polymerizer. The timing of addition of the sodium formaldehyde sulfoxylate solution and cumene hydroperoxide was adjusted according to the degree of polymerization progress. Then, 0.04 parts by weight of a sodium formaldehyde sulfoxylate solution and 0.0225 parts by weight of cumene hydroperoxide were further added into the pressure-resistant polymerizer. Subsequently, the reaction solution in the pressure-resistant polymerizer was stirred for 30 minutes. After 30 minutes and 60 minutes of stirring, 0.0225 parts by weight of cumene hydroperoxide was added into the pressure-resistant polymerizer while stirring was continued. By such an operation, an inner layer of the core was obtained. The polymerization conversion rate was 99.5%. For the polymerization of the inner layer of the core, MMA, BA and ST were used as monomers other than the cross-linking agent. In the polymerization of the inner layer of the core, the ratio (% by weight) of each of the monomers other than the cross-linking agent was determined to be MMA 9. It was 78% by weight, BA61.99% by weight and ST28.23% by weight. Only allyl methacrylate, which is a polyfunctional monomer, was used as a cross-linking agent for the polymerization of the inner layer of the core. In the polymerization of the inner layer of the core, the proportion (% by weight) of the cross-linking agent used was 0.5% by weight of allyl methacrylate when all the monomers other than the cross-linking agent used for the polymerization of the inner layer of the core were 100% by weight. It was.

Next, (a) 5 parts by weight of BA as a monomer other than the cross-linking agent, (b) 0.025 parts by weight of allyl methacrylate which is a polyfunctional monomer as the cross-linking agent, and (c) t-butyl hydroperoxide. A mixture consisting of 0.0089 parts by weight was added into the pressure-resistant polymerizer over 15 minutes. After the addition, 0.0089 parts by weight of t-butyl hydroperoxide was added into the pressure-resistant polymerizer, and 0.012 parts by weight of t-butyl hydroperoxide was further added into the pressure-resistant polymerizer. Subsequently, the reaction solution in the pressure-resistant polymerizer was stirred for 30 minutes. By such an operation, the core outer layer covering at least a part of the core inner layer was polymerized to obtain a core layer having a core inner layer and a core outer layer. The polymerization conversion rate was 99.1%. Only BA was used as a monomer other than the cross-linking agent for the polymerization of the outer layer of the core. That is, in the polymerization of the core outer layer, the usage ratio (% by weight) of the monomer other than the cross-linking agent is BA 100% by weight when all the monomers other than the cross-linking agent used in the polymerization of the core outer layer are 100% by weight. Met. Only allyl methacrylate, which is a polyfunctional monomer, was used as a cross-linking agent for the polymerization of the outer layer of the core. In the polymerization of the core outer layer, the proportion (% by weight) of the cross-linking agent used was 0.5% by weight of allyl methacrylate when all the monomers other than the cross-linking agent used for the polymerization of the core outer layer were 100% by weight. It was.

Next, 0.025 parts by weight of a sodium formaldehyde sulfoxylate solution was added into the pressure-resistant polymerizer. Subsequently, it is composed of (a) 23.71 parts by weight of MMA, 1.96 parts by weight of BA and 2.33 parts by weight of ST, and (b) 0.0255 parts by weight of t-butyl hydroperoxide as a monomer other than the cross-linking agent. The mixture was added into the pressure-resistant polymerizer over 84 minutes. After the addition, the reaction solution in the pressure-resistant polymerizer was stirred for 60 minutes. By such an operation, the shell layer covering at least a part of the core layer was polymerized to obtain an aqueous latex containing polymer fine particles having a core layer having a core inner layer and a core outer layer and a shell layer. The polymerization conversion rate was 99.7%. For the polymerization of the shell layer, MMA, BA and ST were used as monomers other than the cross-linking agent. In the polymerization of the shell layer, the ratio (% by weight) of each of the monomers other than the cross-linking agent was MMA 84.68 when all the monomers other than the cross-linking agent used in the polymerization of the shell layer were 100% by weight. It was% by weight, BA7% by weight and ST8.32% by weight.

(Examples 2 to 5 and Comparative Example 2)
(A) (a-1) Use ratio (% by weight) of each polymer other than the cross-linking agent, (a-2) Use ratio (% by weight) of the cross-linking agent, and (a-3) Weight fraction of each layer. The polymer fine particles were produced by the same method as in Example 1 except that the ratios shown in Tables 1 and 3 were changed and the amount of the crosslink used was changed as described above in (b).

In Examples 1 to 5, only BA was used as the monomer other than the cross-linking agent for the polymerization of the core outer layer. Therefore, the Tg of the core outer layer in Examples 1 to 5 can be regarded as the same as the Tg of the polybutyl acrylate. The Tg of polybutyl acrylate is −54 ° C. according to the non-patent document “Polymer Handbook 4th Edition” (publisher; Wiley-Interscience). That is, the Tg of the core outer layer in Examples 1 to 5 was −54 ° C.

(Comparative Example 1)
175 parts by weight of deionized water, 0.473 parts by weight of boric acid, 0.0473 parts by weight of sodium carbonate and 0.016 parts by weight of polyoxyethylene lauryl ether phosphoric acid in a pressure-resistant polymerizer equipped with a stirrer and having a volume of 8 L. The heavy part was charged. Here, polyoxyethylene lauryl ether phosphoric acid became sodium polyoxyethylene lauryl ether phosphate in the presence of sodium carbonate, and functioned as an emulsifier.

Next, oxygen was sufficiently removed from the inside of the pressure-resistant polymerizer by replacing the gas inside the pressure-resistant polymerizer with nitrogen while stirring the charged raw materials, so that the inside of the pressure-resistant polymerizer was substantially free of oxygen. After that, the temperature inside the pressure-resistant polymerizer was raised to 80 ° C. Then, (a) 0.637 parts by weight of MMA, 4.524 parts by weight of BA and 1.839 parts by weight of ST as a monomer other than the cross-linking agent, and (b) 0.035 allyl methacrylate which is a polyfunctional monomer as a cross-linking agent. A mixture consisting of parts by weight and (c) 0.035 parts by weight of cumene hydroperoxide was added into the pressure-resistant polymerizer. Next, 0.07 parts by weight of the EDTA / ferrous sulfate mixture and 0.0645 parts by weight of the formaldehyde sulfoxylate sodium solution were added into the pressure-resistant polymerizer. Subsequently, after stirring the reaction solution in the pressure-resistant polymerizer for 15 minutes, 0.0583 parts by weight of cumene hydroperoxide was added into the pressure-resistant polymerizer. Then, the reaction solution in the pressure-resistant polymerizer was stirred for another 15 minutes. Seed particles were obtained by such an operation. The polymerization conversion rate was 94.3%.

Next, the temperature inside the pressure-resistant polymerizer was set to 60 ° C. Subsequently, 0.023 parts by weight of a sodium formaldehyde sulfoxylate solution, 0.0175 parts by weight of cumene hydroperoxide, and 0.042 parts by weight of an aqueous sodium hydroxide solution were added into the pressure-resistant polymerizer. Subsequently, (a) 5.915 parts by weight of MMA, 42.01 parts by weight of BA and 17.075 parts by weight of ST as a monomer other than the cross-linking agent, and (b) allyl methacrylate, which is a polyfunctional monomer as the cross-linking agent, 0. A mixture consisting of 325 parts by weight and (c) 0.363 parts by weight of polyoxyethylene lauryl ether phosphoric acid was added into the pressure-resistant polymerizer over 195 minutes. During the addition of the mixture, 0.023 parts by weight of a sodium formaldehyde sulfoxylate solution and 0.0175 parts by weight of cumene hydroperoxide were added intermittently into the pressure-resistant polymerizer. The timing of addition of the sodium formaldehyde sulfoxylate solution and cumene hydroperoxide was adjusted according to the degree of polymerization progress. Then, 0.04 parts by weight of a sodium formaldehyde sulfoxylate solution and 0.0225 parts by weight of cumene hydroperoxide were further added into the pressure-resistant polymerizer. Subsequently, the reaction solution in the pressure-resistant polymerizer was stirred for 30 minutes. After 30 minutes and 60 minutes of stirring, 0.0225 parts by weight of cumene hydroperoxide was added into the pressure-resistant polymerizer, respectively. By such an operation, a core layer composed of a single layer was obtained. The polymerization conversion rate was 98.7%. For the polymerization of the core layer, MMA, BA and ST were used as monomers other than the cross-linking agent. In the polymerization of the core layer, the ratio (% by weight) of each of the monomers other than the cross-linking agent was determined to be MMA 9. It was 10% by weight, BA64.63% by weight and ST26.27% by weight. Only allyl methacrylate, which is a polyfunctional monomer, was used as a cross-linking agent for the polymerization of the core layer. In the polymerization of the core layer, the proportion (% by weight) of the cross-linking agent used was 0.5% by weight of allyl methacrylate when all the monomers other than the cross-linking agent used for the polymerization of the core layer were 100% by weight. It was.

Next, 0.025 parts by weight of a sodium formaldehyde sulfoxylate solution was added into the pressure-resistant polymerizer. Subsequently, it is composed of (a) 23.71 parts by weight of MMA, 1.96 parts by weight of BA and 2.33 parts by weight of ST, and (b) 0.0255 parts by weight of t-butyl hydroperoxide as a monomer other than the cross-linking agent. The mixture was added into the pressure-resistant polymerizer over 84 minutes. After the addition, the reaction solution in the pressure-resistant polymerizer was stirred for 60 minutes. By such an operation, the shell layer covering at least a part of the core layer was polymerized to obtain an aqueous latex containing polymer fine particles having a core layer composed of a single layer and a shell layer. The polymerization conversion rate was 98.9%. For the polymerization of the shell layer, MMA, BA and ST were used as monomers other than the cross-linking agent. In the polymerization of the shell layer, the usage ratio (% by weight) of the monomer other than the cross-linking agent is MMA 84.68% by weight when all the monomers other than the cross-linking agent used in the polymerization of the shell layer are 100% by weight. , BA7% by weight and ST8.32% by weight.

(Comparative Example 3)
Comparison except that the ratio (% by weight) of each polymer used as a monomer other than the cross-linking agent was changed to the ratio shown in Table 3 and the amount of emulsifier used was changed as described above. Polymer fine particles were produced by the same method as in Example 1.

In Tables 1 and 3, the weight fraction (% by weight) of each layer was defined as the weight fraction (% by weight) of each layer with respect to 100% by weight of the polymer fine particles. In Tables 1 and 3, the "ratio of monomers other than the cross-linking agent used (% by weight)" in each layer is the polymerization of each layer with respect to all the monomers (100% by weight) other than the cross-linking agent used for the polymerization of each layer. The ratio (% by weight) of the monomer other than the cross-linking agent used in was used. In Tables 1 and 3, the "ratio of cross-linking agent used (% by weight)" in each layer is the cross-linking agent used for the polymerization of each layer with respect to all the monomers (100% by weight) other than the cross-linking agent used for the polymerization of each layer. Was used (% by weight).

Polymer microparticles of Examples 1-5, for the Hansen solubility parameter [delta] _B of the core layer, the absolute value of the Hansen solubility parameter [delta] _C each difference in Hansen solubility parameter [delta] _A and a shell layer of the core inner layer, i.e. | [delta] _A - δ _B | and | δ _{B −} δ _C | are 0.5. Comparative Example 1 has a core layer composed of a single layer, and the absolute value of the difference between the _{Hansen solubility parameter of the core layer and the Hansen solubility parameter δ C of the shell layer is 0.} It can be seen that the polymer fine particles of Examples 1 to 5 are superior in blocking resistance to the polymer fine particles of Comparative Example 1. That is, it can be said that the polymer fine particles of Examples 1 to 5 are less likely to impregnate the core layer of the shell layer than the polymer fine particles of Comparative Example 1.

In the polymer fine particles of Examples 1 to 5, the absolute value of the difference between the refractive index of the core layer and the refractive index of the shell layer is 0.0026. As a result, it can be seen that the polymer fine particles of Examples 1 to 5 have a small Haze value and are excellent in transparency.

The polymer fine particles of Examples 1 to 3 have the same composition of the core inner layer and the shell layer, and the weight fraction of each layer is the same. In Examples 1 and 2, the total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the core outer layer is a monomer other than the crosslinker in the core outer layer. It is 0.1% by weight to 1.0% by weight with respect to 100% by weight of all the structural units derived from. On the other hand, in Example 3, the total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the core outer layer is a monomer other than the crosslinker in the core outer layer. It is 5.0% by weight with respect to 100% by weight of all the constituent units derived from. The polymer fine particles of Examples 1 and 2 have a smaller increase in the adhesive force after the powder or granular material breakage test with respect to the adhesive force before the powder or granular material breakage test as compared with the polymer fine particles of Example 3. I understand. That is, the polymer fine particles of Examples 1 and 2 have a peeling of the blocking inhibitor adhering to the surface of the polymer fine particles (powder / granular material) in the manufacturing process as compared with the polymer fine particles of Example 3. It can be said that there are few.

The polymer fine particles and the resin composition according to the embodiment of the present invention are excellent in blocking resistance and transparency. Therefore, one embodiment of the present invention can be suitably used especially for optical applications where impact resistance is required. One embodiment of the present invention includes, for example, an image field such as a photographing lens for a camera, a lens field such as a pickup lens for an optical disk, an optical recording field for an optical disk, an optical communication field such as an optical fiber, and a vehicle such as an automobile headlight. Fields, medical equipment fields such as lenses for endoscopes, construction and building materials fields such as road signs, liquid crystal display parts such as light guide plates for liquid crystal displays, display-related parts such as projector screens and head-up displays, for microwave cooking It can be used for containers, housings for home appliances, toys, sunglasses and stationery.

Claims (6)

A core layer having an inner core layer which is the innermost layer and an outer core layer formed so as to cover at least a part of the inner core layer.
It has a shell layer formed so as to cover at least a part of the core outer layer.
The absolute value of the difference between the refractive index of the core layer and the refractive index of the shell layer is 0 to 0.003.
The core layer contains 2% by weight to 20% by weight of the outer core layer in 100% by weight of the core layer.
Hereinafter, polymer fine particles satisfying all of (i) to (iii):
(I) 0.3 ≤ | δ _{A −} δ _B |,
(Ii) 0.3 ≦ | δ _{B −} δ _C |, and (iii) 0.1 ≧ | δ _{A −} δ _C |;
here,
δ _A is a Hansen solubility parameter of the monomer constituting the inner layer of the core.
δ _B is a Hansen solubility parameter of the monomer constituting the core outer layer.
δ _C is the Hansen solubility parameter of the monomer constituting the shell layer. The inner layer of the core
(I) As a constituent unit
(I-1) A structural unit (unit a) derived from an alkyl acrylate of 50% by weight to 90% by weight.
(I-2) A structural unit (unit b) derived from an aromatic vinyl compound, which is 10% by weight to 50% by weight.
(I-3) A structural unit (unit c) 0% by weight derived from a vinyl compound other than the alkyl acrylate and the aromatic vinyl compound, which is copolymerizable with the alkyl acrylate and / or the aromatic vinyl compound. Contains ~ 20% by weight,
(Ii) The polymer fine particles according to claim 1, wherein the total of the unit a, the unit b, and the unit c is 100% by weight. The shell layer is
(I) As a constituent unit
(I-1) A structural unit (unit: a) derived from an alkyl acrylate, which is 85% by weight to 97% by weight.
(I-2) A structural unit (unit b) derived from an aromatic vinyl compound, 3% by weight to 15% by weight,
(I-3) A structural unit (unit c) 0% by weight derived from a vinyl compound other than the alkyl acrylate and the aromatic vinyl compound, which is copolymerizable with the alkyl acrylate and / or the aromatic vinyl compound. Contains ~ 12% by weight,
(Ii) The polymer fine particles according to claim 1 or 2, wherein the total of the unit a, the unit b, and the unit c is 100% by weight. The core outer layer is
(I) As a constituent unit
(I-1) A structural unit (unit a) derived from an alkyl acrylate: 90% by weight to 100% by weight.
(I-2) A structural unit (unit b) derived from an aromatic vinyl compound, 0% by weight to 10% by weight,
(I-3) A structural unit (unit c) 0% by weight derived from a vinyl compound other than the alkyl acrylate and the aromatic vinyl compound, which is copolymerizable with the alkyl acrylate and / or the aromatic vinyl compound. Contains 10% by weight,
(Ii) The polymer fine particles according to any one of claims 1 to 3, wherein the total of the unit a, the unit b and the unit c is 100% by weight. An antiblocking agent is further contained on the surface of the polymer fine particles,
The core outer layer has a glass transition temperature of −60 ° C. to 30 ° C.
The core outer layer further contains, as a structural unit, a structural unit derived from a polyfunctional monomer and / or a crosslinkable monomer.
The total content of the structural unit derived from the polyfunctional monomer and the structural unit derived from the crosslinkable monomer in the core outer layer is the polyfunctional monomer and the crosslinkable monomer in the core outer layer. The polymer fine particles according to any one of claims 1 to 4, which are 0.1% by weight to 1.0% by weight based on 100% by weight of all the constituent units derived from the monomers other than the above. The polymer fine particles according to any one of claims 1 to 5 and a matrix resin are contained.
A resin composition in which the absolute value of the difference between the refractive index of the polymer fine particles and the refractive index of the matrix resin is 0 to 0.003.