JP2606320B2 - Hollow polymer particles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hollow polymer particle having a novel structure comprising at least two polymer layers and having pores therein. More specifically, the present invention relates to a hollow polymer particle which is useful as a light scattering agent, a light scattering auxiliary, or a microcapsule in a coating agent for paper, fiber, leather, or the like, or various paints.

<Prior Art> Polymer particles having pores inside the particles are used as microcapsule particles by including various substances in the inner hole, or hollow particles used as a light scattering agent by making the inner hole hollow. It is used as an organic material such as polymer particles.

Conventionally, the following method is known as a method for producing polymer particles having an inner hole.

(I) A method in which a foaming agent is contained in polymer particles, and then the foaming agent is foamed.

(II) A method of encapsulating a polymer with a volatile substance such as butane and then gasifying and swelling the volatile substance.

(III) A method in which a polymer is melted, and a gas jet such as air is blown onto the polymer to enclose air bubbles.

(IV) A method in which an alkali-swellable substance is permeated into polymer particles to swell the alkali-swellable substance.

(V) A method of preparing a w / o / w type monomer emulsion and conducting polymerization.

(VI) A method of polymerizing a monomer in a suspension solution in which a pigment is suspended in an unsaturated polyester solution.

(VII) A two-step cross-linking method in which cross-linked polymer particles are used as seeds, and polymers having different compatibility are polymerized and cross-linked on the seeds.

(VIII) A method of producing a polymer by polymerizing shrinkage.

<Problems to be Solved by the Invention> However, in these production methods, it has been difficult to control the production conditions or to stably produce the polymer particles having the desired inner pores. Further, conventional hollow fine particles, when added as a light scattering agent to the coating film forming material, had the required physical properties of opacity, but gloss, coating film strength, elasticity, adhesion, water resistance, and water resistance. Alkalinity, solvent resistance,
The balance of physical properties such as weather resistance was poor. Particularly, in the conventional method for producing polymer particles having internal light, it was necessary to use a polymer having a high glass transition temperature as a shell polymer in order to develop internal pores in the polymer particles. A fatal problem that a hollow polymer particle having a good particle size cannot be obtained.

An object of the present invention is to provide a novel hollow polymer particle.

Other objects of the present invention, together with excellent concealing properties, gloss, coating strength, elasticity, adhesion, water resistance, alkali resistance,
An object of the present invention is to provide hollow polymer particles having an excellent balance of physical properties such as solvent resistance and weather resistance.

Still another object of the present invention is to provide hollow polymer particles having an adhesive property which cannot be obtained by a conventional method.

Still another object of the present invention is to provide an industrially advantageous method for producing the novel hollow polymer particles of the present invention.

Still other objects and advantages of the present invention will be apparent from the following description.

<Means for Solving the Problem> According to the present invention, the above objects and advantages of the present invention are hollow polymer particles having at least two polymer layers, and (1) an average particle diameter of 0.15 to (2) the average ratio of the equivalent hollow diameter to the equivalent particle size for each particle is in the range of 0.2 to 0.8, (3) the proportion of the toluene-insoluble portion is 20 to 90% by weight, (4) The melt flow rate under conditions of 180 ° C. and 10 kgf / cm ² is 0.1 to 1 g / 10 min. (5) The inner layer of the two polymer layers is represented by the following formula (a) Wherein R ¹ is a hydrogen atom or a methyl group, X is an n-functional organic group or a bond, and n is a number of 2 or 3, provided that n R ^1s are the same And when X is a bond, n is 2; a polymerized unit represented by the following formula (b): Here, R ² is a hydrogen atom or a methyl group, and Y is a phenyl group, a phenyl group substituted by a halogen atom, an alkyl group or a vinyl group, a halogen atom, a cyano group, 18 is an alkanoyloxy group, an alkoxy group, a pyridyl, a pyridylalkyl, an aminoalkoxy or an amide group, a polymerization unit represented by the following formula (c): Here, R ³ and R ⁵ are the same or different and are a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom, a carboxyl group or a carboxylate group, and R ⁶ is a hydrogen atom and has 1 carbon atom.
An alkyl group having -18, a hydroxyalkyl group having 2-10 carbon atoms, or an organic group having at least one member selected from glycidyl, amino, cyano and a carbon-carbon double bond, or an equivalent of a base. A polymerized unit represented by the formula: and optionally, the following formula (d) Wherein R ⁷ is a hydrogen atom or a methyl group, a polymerized unit represented by the following formula: and a cross-linked polymer consisting of: (6) The outer layer of the two-layered polymer has the formula (b)
This is achieved by a hollow polymer particle comprising a non-crosslinked polymer comprising at least one polymer unit selected from the group consisting of (c) and (d).

According to the present invention, the above hollow polymer particles (Q) of the present invention
Is (m-1) a crosslinked polymer comprising the polymerized units of the above formulas (a), (b) and (c) and optionally further the polymerized unit of (d), and having an average particle diameter of 0.05 to 15 μm. Hollow polymer particles (hereinafter referred to as pre-hollow polymer particles (P))
(M-2) and the following formula (b1) Here, the definitions of R ² and Y are the same as those in the above formula (b), and a monomer represented by the following formula (c1) Here, the definitions of R ³ , R ⁴ , R ⁵ , and R ⁶ are the same as in the above formula (c), and a monomer represented by the following formula (d1): CH ₂ = CR ⁷ -CH = CH ₂ ( d1) Here, the definition of R ⁷ is the same as that of the above formula (d). At least one monomer selected from the group consisting of monomers represented by the following formula is simply referred to as the pre-hollow polymer particles (P). It can be produced by subjecting to polymerization in an aqueous medium at a pH of less than 7 in the presence of 5 parts by weight or less of an emulsifier and / or dispersant per 100 parts by weight of the total of the monomer (m-2).

The pre-hollow polymer particles (P) used in the above method are, as described above, the above formulas (a), (b),
It is composed of the polymerized unit of (c) and optionally further the polymerized unit of (d) and has an average particle diameter in the range of 0.05 to 15 μm.

The pre-hollow polymer particles (P) are described in, for example, JP-A-61-26251.
No. 0, JP-A-61-66710, and the like, and the method of (VII) shown in the prior art section, and JP-A-61-87734, JP-A-61-86941, and JP-A-62-286. 127336, JP-A-62-156
No. 387, etc., as shown in the section of the prior art (VII
It can be suitably produced by the method of I). By using the pre-hollow polymer particles obtained by such a method, the hollow polymer particles (Q) of the present invention, which are particularly excellent in hiding properties, can be produced. In particular, according to the method (VIII), it is easy to control the inner and outer diameters of the obtained pre-hollow polymer particles (P), and by using them, not only concealing properties but also solvent resistance and heat resistance can be obtained. The hollow polymer particles of the present invention are also excellent in the above. The method (VIII) is particularly preferred. Among the methods of (VIII), the method of JP-A-62-127336 is most preferable. According to this method, further excellent polymerization stability and productivity can be achieved in the polymerization of the pre-hollow polymer particles (P).

Thus, according to the present invention, the pre-hollow polymer particles (P) have the following formula (a1) Wherein R ¹ is a hydrogen atom or a methyl group, X is an n-functional organic group or a bond, and n is a number of 2 or 3, provided that n R ^1s are the same And when X is a bond, n is 2; a monomer represented by the following formula (b1): Here, R ² is a hydrogen atom or a methyl group, and Y is a phenyl group, a phenyl group substituted by a halogen atom, an alkyl group or a vinyl group, a halogen atom, a cyano group, A alkanoyloxy group, an alkoxy group, a pyridyl, a pyridylalkyl, an aminoalkoxy or an amide group of 18; a monomer represented by the following formula (c1): Here, R ³ and R ⁵ are the same or different and are a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom, a carboxyl group or a carboxylate group, and R ⁶ is a hydrogen atom and has 1 to 1 carbon atoms.
An alkyl group of 18 or a hydroxyalkyl group having 2 to 10 carbon atoms or glycidyl, amino, cyano and carbon-
An organic group having at least one member selected from a carbon double bond or an equivalent of a base, and if necessary, the following formula (d1) Here, R ⁷ is a hydrogen atom or a methyl group. A monomer mixture (m-1) of the following formula: is a polymer having a composition different from that of the polymer from this monomer mixture (hereinafter referred to as “m-1”). , The other polymer particles (1) to 100 parts by weight of the monomer mixture (m-1) in the presence of particles of the different polymer (S).
It can be produced by polymerizing in an aqueous medium, using in parts by weight.

Examples of the monomer represented by the formula (a1) include divinyl monomers such as divinylbenzene, ethylene glycol dimethacrylate, 1,3 butylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and allyl methacrylate, or trivinyl monomers. can do. Particularly, divinylbenzene, ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate are preferred.

Examples of the monomer represented by the above formula (b1) include styrene, α-methylstyrene, p-methylstyrene, ethylstyrene, vinyltoluene, halogenated styrene,
Aromatic vinyl monomers such as vinyl naphthalene; α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-1-pentene and 4-methyl-1-pentene; vinyl fluoride; Vinyl halides such as vinyl bromide; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; vinyl acetate; organic acid vinyls such as vinyl propionate and vinyl stearate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether Amide monomers such as acrylamide, methacrylamide and N-methylol methacrylamide; alkenylpyridines such as vinylpyridine and propenylpyridine; aminoalkyl such as aminoethyl vinyl ether and dimethylaminoethyl vinyl ether And the like can be exemplified vinyl ether compounds.

Examples of the monomer represented by the above formula (c1) include unsaturated mono- or dicarboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, or dicarboxylic acids thereof. Acid anhydrides; (meth) acrylate monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, acrylic 2-ethylhexyl, methyl methacrylate, butyl methacrylate, lauryl methacrylate; crotonic esters; Dicarboxylic acid monoesters or diesters such as monomethyl itaconate and dimethyl maleate; hydroxy of ethylenically unsaturated carboxylic acids such as 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate and β-hydroxyethyl (meth) acrylate Alkyl esters; methyl Amino group-containing alkyl esters of ethylenically unsaturated carboxylic acids such as minoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate; cyano group-containing alkyls of ethylenically unsaturated carboxylic acids such as cyanomethyl acrylate and 2-cyanoethyl acrylate Esters; aminoalkylamides of ethylenically unsaturated carboxylic acids such as methylaminoethyl (meth) acrylamide and dimethylaminoethyl (meth) acrylamide; glycidyl esters of ethylenically unsaturated carboxylic acids such as glycidyl (meth) acrylate And the like.

As the monomer represented by the above formula (d1), for example, 1,
Examples thereof include aliphatic conjugated diene monomers such as 3-butadiene, 2-methyl-1,3-butadiene, and 2-chloro-1,3-butadiene.

Further, from these monomers, pre-hollow polymer particles (P)
The other polymer (heterogeneous polymer (S)) used in the production of the above is different from the polymer of the monomer (m-1) as a raw material of the pre-hollow polymer, and Those which easily dissolve or swell in water are preferably used.

Specific examples of such a heteropolymer include, for example, polystyrene, carboxy-modified polystyrene, carboxy-modified styrene-butadiene copolymer, styrene-butadiene copolymer, styrene-acrylester copolymer, styrene-methacrylester copolymer, acrylester copolymer, methacrylester copolymer,
Carboxy-modified styrene acrylic ester copolymer,
Examples thereof include a carboxy-modified styrene methacryl ester copolymer, a carboxy-modified acrylic ester copolymer, and a carboxy-modified methacryl ester copolymer.

Of these, especially polystyrene or styrene component
Styrene copolymers containing greater than or equal to weight percent are preferred.

The pre-hollow polymer particles (P) are a monomer mixture (m-m) comprising the monomers represented by the above (a1), (b1) and (c1) and optionally further comprising the monomer represented by (d1).
1) 1 to 100 parts by weight, preferably 2 to 50 parts by weight, more preferably 5 to 50 parts by weight of the different polymer (S) per 100 parts by weight
It is prepared by using 20 parts by weight and subjecting them to polymerization in an aqueous medium.

When the amount of the heterogeneous polymer is less than 1 part by weight, the effect of forming the inner hole is small, and when the amount of the heterogeneous polymer exceeds 100 parts by weight, the formation of the inner hole tends to be suppressed, which is not preferable.

Thus, a particularly preferred method for producing the pre-hollow polymer particles (P) is that, within the scope of the above-mentioned method for producing the pre-hollow polymer particles (P), the monomer (m-1) a1), (b1), (c1) and a hydrophilic monomer selected from the monomers (b1) and (c1) in a range of 1 to 80% by weight, and the monomers (b1) and (c1). This method uses a monomer mixture consisting of 99% by weight and 0 to 70% by weight of another copolymerizable monomer selected from monomers (b1), (c1) and (d1).

Examples of the hydrophilic monomer selected from the monomers (b1) and (c1) include vinyl pyridine, glycidyl acrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, methyl methacrylate, acrylonitrile, acrylamide, methacrylamide,
N-methylol acrylamide, N-methylol methacrylamide, acrylic acid, methacrylic acid, itaconic acid,
Examples thereof include fumaric acid, sodium styrene sulfonate, vinyl acetate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate.

Of these, those preferably used are unsaturated carboxylic acids such as methacrylic acid, methyl methacrylate, vinylpyridine, 2-hydroxyethyl methacrylate and the like. The solubility of these hydrophilic monomers in water is preferably 0.5% by weight or more, particularly preferably 1% by weight or more.

The other copolymerizable monomer selected from the monomers (b1), (c1) and (d1) can be used without any particular limitation, but may be an aromatic vinyl compound as exemplified above, Preferred are ethylenically unsaturated carboxylic acid alkyl esters, vinyl cyanides, and aliphatic conjugated dienes,
In particular, styrene, alkyl methacrylate having an alkyl group having 3 or more carbon atoms, and alkyl methacrylate having an alkyl group having 2 or more carbon atoms are preferable.

A more preferred composition of the monomer mixture (m-1) is 2 to 60% by weight of the monomer (a1) (crosslinking monomer), and a hydrophilic monomer 40 selected from the monomers (b1) and (c1).
9898% by weight and 0 to 70% by weight of another copolymerizable monomer selected from monomers (b1), (c1) and (d1).

If the amount of the hydrophilic monomer used is too small, the phase separation of the heterogeneous polymer (S) is insufficient, or the heterogeneous polymer is exposed on the surface of the polymer particles, and the formation of the inner hole is uncertain. This is not preferred because of the tendency to occur. Also, if the amount of the crosslinkable monomer is too small, the strength of the particles during polymerization becomes insufficient and the whole particles shrink, and the internal pores are formed due to insufficient strain due to polymerization shrinkage inside the particles. Even when the polymer particles disappear or have polymer particles having inner pores, problems such as a decrease in the strength of the shell tend to occur.

On the other hand, if the amount of the crosslinkable monomer used is an issue, the heterogeneous polymer tends to be rejected to the outside of the polymer particles generated during the polymerization, and the resulting polymer particles do not have a true spherical shape, but have irregularities. This causes a problem of certain agglomerated particles.

A preferred embodiment of the method for producing the pre-hollow polymer particles (P) is as follows. This preferred embodiment is based on the polymerization technique of JP-A-62-127336. (A) A monomer mixture and, if necessary, an oily substance are absorbed by fine particles of a different polymer (seed polymer). Then, a method of polymerizing the monomer mixture or (ii) dissolving a different polymer in the monomer mixture and, if necessary, an oily substance to form an oily solution, and finely dispersing the oily solution in water to obtain an oil-in-water This is a method in which a drop-type emulsion is produced, and then the above monomer component is polymerized. As described above, the presence of the oily substance together with the heterogeneous polymer makes it easy to control the diameter of the inner pore of the polymer particles.

When the heterogeneous polymer (S) is used in the form of particles according to the method (a), it functions as seed polymer particles, and the monomer mixture and the oily substance are absorbed into the particles. The polymer preferably has good absorbability of the monomer mixture and the oily substance.
Therefore, it is preferable to use a polymer having a small molecular weight as the heterogeneous polymer. For example, the number average molecular weight is 20,000 or less, preferably 10,000 or less, and more preferably 700 to 7,000. Here, the number average molecular weight is determined by dissolving a heterogeneous polymer in a good solvent thereof, and gel-permeation chromatography (GP)
C), which can be obtained by measurement by a usual method such as an osmotic molecular weight measuring device, a vapor pressure lowering molecular weight measuring device, or the like.

When the number average molecular weight of the different polymer is larger than 20,000,
The amount of monomer that is not absorbed by the seed polymer particles increases, which not only facilitates the production of a large amount of fine particles that do not become polymer particles having inner pores by being polymerized separately from the seed polymer particles in the aqueous dispersion, but also makes the polymerization system improper. A stable problem arises.

Further, the particle diameter of the heterogeneous polymer used as the seed polymer particles is preferably 0.3 to 0.8 times the outer diameter of the target pre-hollow polymer particles (P).

The method for producing a heterogeneous polymer used as such a seed polymer particle is not particularly limited. For example, it can be produced using a production method such as emulsion polymerization or suspension polymerization using a relatively large amount of a chain transfer agent. .

When a heterogeneous polymer is used as the seed polymer particles, a high lipophilic substance having a solubility in water of 10 ^-3 % by weight or less is previously absorbed in the seed polymer particles so that a monomer for the seed polymer particles can be absorbed. The absorption capacity of the mixture and oily substances can be increased.

In the case where the means for causing the seed polymer particles to absorb the highly lipophilic substance is used as described above, a preferable result is obtained even if the number average molecular weight of the different polymer exceeds 20,000.

Examples of the highly lipophilic substance include 1-chlordodecane, octanoyl penoxide, 3,5,5-trimethylhexanoyl peroxide and the like.

In order to absorb these highly lipophilic substances into the seed polymer particles, for example, an aqueous dispersion in which the highly lipophilic substance is finely dispersed is prepared, and this dispersion is mixed with an aqueous dispersion of the seed polymer particles. The highly lipophilic substance is preferably brought into contact with the seed polymer particles.

The particle diameter of the pre-hollow polymer particles (P) having inner pores obtained when the seed polymer particles are used is approximately equal to the particle diameter of the seed polymer particles which have been enlarged by absorbing the polymerizable monomer and the oily substance. Matches. Therefore, by adjusting the particle size of the seed polymer particles, the relative amount of the seed polymer particles to the monomer mixture and the oily substance, and the like, it is possible to control the particle size of the pre-hollow particles having inner pores to be generated. it can.

Specifically, pre-hollow polymer particles (P) having an inner hole
In the production of 0.1 ~ excellent whiteness and hiding power
To obtain pre-hollow polymer particles having a particle diameter of 0.6 μm, seed polymer particles having a particle diameter of 0.06 to 0.40 μm may be used.

Another advantage of using the seed polymer particles is that when polymer particles having a small particle diameter of 1 μm or less are produced, monomer droplets having a small particle diameter can be easily and stably formed. There is also.

When a different polymer is used in the method (b), the molecular weight of the different polymer is not particularly limited, and a polymer having a number average molecular weight of 20,000 or more can be preferably used.

In this production method (b), an oily substance can be used if necessary. Such an oily substance is not particularly limited as long as it has a solubility in water of 0.2% by weight or less, and any of vegetable oil, animal oil, mineral oil and synthetic oil can be used.

In this production method (b), pre-hollow polymer particles having an inner hole can be obtained without using an oily substance. However, the diameter of the inner hole can be reduced by using an oily substance and adjusting the amount of use. It can be controlled reliably.

Examples of the oily substance include lard oil, olive oil, coconut oil, castor oil, cottonseed oil, kerosene, benzene, toluene, xylene, butane, pentane, hexane, cyclohexane, carbon trisulfide, carbon tetrachloride, and the like. .

Further, as the oily substance, high boiling point oils such as eugenol, geraniol, cyclamenaldehyde, citronellal, dioctyl phthalate and dibutyl phthalate can also be used. The use of these high-boiling oils gives capsule-shaped polymer particles containing a fragrance, a plasticizer and the like in the core.

The amount of the oily substance to be used is generally 0 to 1,000 parts by weight, preferably 0 to 300 parts by weight, based on 100 parts by weight of the monomer mixture. In addition, inert solvents that are usually contained in those supplied as the crosslinkable monomer material can also be introduced as the oily substance here. If the amount of the oily substance is excessively large, there is a problem that the monomer component is relatively insufficient, the film thickness of the outer shell of the polymer becomes thin, the strength of the capsule becomes insufficient, and the capsule is easily crushed.

The concept of the oily substance can include the monomers (a1), (b1), (c1), and (d1) described above. In this case, in the polymerization step, by stopping the polymerization in a state where the monomer remains in the polymer particles to be produced, the remaining monomer can be used as an oily substance. In this case, the polymerization yield needs to be 97% or less, preferably 95% or less. For this purpose, a method of performing polymerization by adding a small amount of a polymerization inhibitor, a method of lowering the temperature of the reaction system during the polymerization, or a method of stopping the polymerization by adding a polymerization terminator during the polymerization can be adopted. .

In this production method (b), the capsule-shaped polymer particles containing an oily substance or the water-containing hollow polymer particles obtained by replacing the oily substance with water as described above are separated from the aqueous dispersion and dried. Thereby, pre-hollow polymer particles having a space inside can be obtained.

The pre-hollow polymer particles (P) obtained by using the above-mentioned polymerization technique have the following advantages.

(I) The manufacturing process is simple and the productivity is excellent.

(Ii) Production control is easy, and pre-hollow polymer particles having the desired outer diameter and inner diameter can be obtained.

(Iii) Since the pH of the aqueous dispersion of the pre-hollow polymer particles can be freely selected, it can be used without limitation as a monomer of the polymer formed on the surface of the pre-hollow polymer particles.

(Iv) By using the pre-hollow polymer particles as the pre-hollow polymer particles (P) in the method of the present invention, the obtained hollow polymer particles of the present invention have further excellent concealing properties, gloss,
Shows adhesion and coating strength.

According to the present invention, pre-hollow polymer particles (P) having an average particle diameter of 0.05 to 15 μm, preferably 0.15 to 10 μm can be advantageously produced by the above-described method.

Particles having an average particle diameter of less than 0.05 μm are difficult to produce,
Even if it can be produced, it is not preferable because it contains at least a part of polymer particles having no hollow. On the other hand,
If it exceeds 15 μm, the particle size distribution becomes broad, and the hollow polymer particles of the present invention obtained by using this as the pre-hollow polymer particles (P) cannot be obtained as having a uniform particle size, which is not preferable.

The ratio of the inner diameter to the outer diameter of the pre-hollow polymer particles (P) is preferably 0.25 to 0.9 times. If it is 0.25 times or more, 1
It is preferable since hollow polymer particles having the desired physical properties of the present invention can be obtained. On the other hand, when it is more than 0.9 times, the production of pre-hollow polymer particles (P) becomes difficult. Is not preferred.

The pre-hollow polymer particles (P) preferably have a toluene insoluble content at room temperature of 80% by weight or more, and have a glass transition temperature Tg of 150 ° C. or more or cannot be measured.

As described above, the pre-hollow polymer particles (P) in the present invention have a composition of a crosslinked polymer composed of the polymerized units (a), (b), (c) and optionally (d).

Preferred pre-hollow polymer particles (P) in the present invention
According to the preferred production method described above, (i) polymerized units (a), (b), (c) and (d)
Based on the total of 20 to 99% by weight of a hydrophilic polymerized unit selected from the polymerized units (b) and (c), and 1
A crosslinked polymer comprising from 0 to 80% by weight and 0 to 70% by weight of another polymerizable polymerizable unit selected from the polymer units (b), (c) and (d); and (ii) the copolymer Is a polymer (S) having a different composition, and (iii) has a composition of 1 to 100 parts by weight of the polymer (ii) based on 100 parts by weight of the polymer (i). More preferably, component (i) comprises 40 to 98% by weight of a hydrophilic polymerized unit, 2 to 60% by weight of a polymerized unit (a), and 0 to 70% by weight of another polymerizable unit.

Regarding the type of the hydrophilic polymerized unit in the component (i),
Although not particularly limited, it preferably comprises a polymerized unit derived from an unsaturated carboxylic acid and / or another hydrophilic monomer.

As the hydrophilic polymerized unit in the component (i), more preferably, the polymerized unit is composed of an unsaturated carboxylic acid and / or another hydrophilic monomer and the composition ratio of which is 1 to 70. % By weight and 30 to 99% by weight of polymerized units derived from other hydrophilic monomers.

By using the pre-hollow polymer particles (P) having these preferable or more preferable components (i), according to the present invention, it is possible to produce hollow fine particles having the object properties of the present invention which are more excellent. Can be.

The hollow polymer particles (Q) of the present invention are, as described above,
The pre-hollow polymer particles (P) are mixed with at least one selected from the group consisting of monomers (m-2), that is, monomers (b1), (c1) and (d1), to form a pre-hollow polymer particle (P). In the presence of 5 parts by weight or less of an emulsifier and / or a dispersant per 100 parts by weight of the total of the polymer particles (P) and the monomer (m-2),
It can be produced by subjecting to polymerization in an aqueous medium under conditions having a pH of less than 7.

Monomer (b1) used as monomer (m-2),
As (c1) and (d1), the same ones as described above for the pre-hollow polymer particles (P) can be used. Among the monomers (b1), preferred as the component (m-2) are, for example, aromatic vinyl monomers such as styrene and p-methylstyrene; vinyl cyanide compounds such as acrylonitrile; and halogens such as vinyl fluoride. Vinyl acid; organic acid vinyl such as vinyl acetate; amide monomers such as acrylamide; Particularly preferred is styrene.

The amount of the monomer (b1) to be used is preferably 0 to 99.5% by weight, more preferably 10 to 99.5% by weight based on the total of the component (m-2).
%, Particularly preferably from 20 to 99.5% by weight. It is preferable from the viewpoint of light scattering and gloss given to the hollow polymer particles of the present invention.

Among the monomers (c1), preferred as the component (m-2) are, for example, unsaturated mono- or dicarboxylic acids such as acrylic acid, methacrylic acid and itaconic acid; methyl (meth) acrylate, ethyl (meth) acrylate (Meth) acrylate monomers such as butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; mono- or diesters of dicarboxylic acids such as monomethyl itaconate and dimethyl maleate; 2-hydroxyethyl ( Hydroxyalkyl esters of ethylenically unsaturated carboxylic acids such as (meth) acrylate; cricidyl esters of ethylenically unsaturated carboxylic acids such as glycidyl (meth) acrylate; Particularly preferably, (meth) acrylic acid, itaconic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth)
Acrylate.

The amount of the monomer (c1) used is preferably 0.5 to 100% by weight, more preferably 0.5 to 90% by weight based on the total of the component (m-2).
%, Particularly preferably 0.5 to 80% by weight.

Further, as the monomer (c1), an unsaturated carboxylic acid such as (meth) acrylic acid or itaconic acid is preferably used in an amount of 0.5 to 50% by weight, more preferably 1 to 50% by weight, based on the total amount of the component (m-2).
It is preferably used in an amount of from 40 to 40% by weight, particularly preferably from 2 to 30% by weight, since polymerization stability is obtained.

Further, a carboxyl group 1 is replaced by a part of the monomer (c1).
Unsaturated carboxylic acids having a molecular weight of 100 or more unsaturated carboxylic acid monomers per unit can also be used. These examples are shown below by a general formula. When this unsaturated carboxylic acid is used, the strength and adhesiveness of the hollow polymer particles of the present invention are further improved.

(Where R ₁₁ , R ₁₂ and R ₁₃ are H or an alkyl group having 1 to 20 carbon atoms) (Where X is And Y is H or CH _3. (In the above two formulas, R ₁₄ , R ₁₅ , and R ₁₆ are H or an alkyl group having 1 to 12 carbon atoms, EO is an ethylene oxide group, and PO is a propylene oxide group.) (In the above two formulas, R ₁₇ and R ₁₈ are H or carbon 1
These higher carboxylic acid monomers have the following formula: Is particularly preferred.

Among the monomers (d1), particularly preferred as the component (m-2) is 1,3-butadiene.

The amount of the monomer (d1) used is preferably 0 to 80% by weight, more preferably 0 to 60% by weight, and particularly preferably 0 to 50% by weight, based on the total of the component (m-2). The hollow polymer particles of the present invention are preferred from the viewpoint of balance between strength, adhesiveness, weather resistance, light resistance and heat resistance.

The calculated Tg of the copolymer of the monomer mixture (m-2) used for producing the hollow polymer particles of the present invention is preferably
40-150 ° C. When strength, adhesiveness, pigment binding property, etc. are strongly required for the particles, 40 to 100 ° C. is particularly preferable,
70-150 ° C when gloss and light scattering are strongly required
Is particularly preferred.

The polymerization step is carried out in the presence of less than 5 parts by weight of an emulsifier and / or dispersant per 100 parts by weight of the total weight of the pre-hollow polymer particles (P) and the monomer mixture (m-2), under the condition that the pH is less than 7, and Performed in the medium. A monomer or monomer mixture (m-2) on the surface of the pre-hollow polymer particles (P)
The average particle diameter is 0.15 to 20 μm
The hollow polymer particles (Q) of the present invention in the range of (1) are formed.

In the polymerization step, the monomer or monomer mixture (m
The addition method of -2) includes pre-hollow polymer particles (P)
And the monomer or monomer mixture (m-2) is stirred and polymerized, and the monomer mixture (m-2) is continuously or dividedly supplied to the polymerization system in which the pre-hollow polymer particles (P) are present to carry out polymerization. There is an increment polymerization method to be performed. In order to efficiently and stably copolymerize the polymerizable monomer on the surface of the pre-hollow polymer particles, an increment polymerization method is preferable.

As the emulsifier and / or dispersant (suspension protective agent), any of anionic, nonionic, cationic and amphoteric types can be used.

These can be used alone or in combination of two or more.

Examples of the emulsifier include rosinates such as potassium rosinate and sodium rosinate; aliphatic sodium and potassium salts such as potassium oleate, potassium laurate, sodium laurate, sodium stearate, and potassium stearate; and sodium lauryl sulfate. Anionic emulsifiers such as alkyl allyl sulfonates such as sodium dodecylbenzenesulfonate, sodium dialkyl sulfosuccinate, and formalin condensates of naphthalenesulfonic acid; alkyl ester types of polyethylene glycol, alkyl Nonionic emulsifiers such as ether type and alkylphenyl ether type are preferred. Among them, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium dioctylsulfosuccinate, formalin condensate of naphthalenesulfonic acid, and alkylphenyl ether type of polyethylene glycol are preferred.

Examples of the cationic emulsifier include a quaternary ammonium salt type, and when the aqueous dispersion is a cationic type,
Used alone or in combination with nonions.

Examples of the dispersant include hydrophilic synthetic high molecular substances such as polyacrylic acid, polymethacrylic acid, polyvinyl sulfonic acid, polyvinyl alcohol, polyvinyl pyrrolidone, and polyethylene glycol; natural hydrophilic high molecular substances such as gelatin and water-soluble starch; Examples include hydrophilic semi-synthetic polymer substances such as methyl cellulose.

The amount of the emulsifier and / or dispersant used is 5 parts by weight or less, preferably 2 parts by weight or less, more preferably 1 part by weight or less. If it exceeds 5 parts by weight, new particles are generated during polymerization,
It is not preferable because the production efficiency of the vacuum polymer particles of the present invention decreases, and furthermore, the concealing property and the gloss decrease.

Examples of the polymerization initiator include organic hydroperoxides represented by, for example, cumene hydroperoxide, diisopropylbenzene hydroperoxide, paramenthane hydroperoxide, and sugar-containing pyrophosphate, sulfoxylate, and sugar-containing pyrophosphate formulations. Redox initiators in combination with reducing agents represented by mixed / sulfoxylate formulations, etc .; further, persulfates such as potassium persulfate and ammonium persulfate; azobisisobutyronitrile, benzoyl peroxide , Lauroyl peroxide and the like can be used.

Preferably, a persulfate such as potassium persulfate or ammonium persulfate, azobisisobutyronitrile, or benzoyl peroxide is combined with a reducing agent, if necessary. Particularly preferred are persulfates such as potassium persulfate and ammonium persulfate. In these polymerization initiators, radicals tend to concentrate on the surface of the pre-hollow polymer particles, so that the formation of a film by the component (m-2) is efficiently performed. The amount of the polymerization initiator is preferably 0.05 to 2 parts by weight, more preferably 0.05 to 0.8 part by weight, based on the total amount of the pre-hollow polymer particles (P) and the monomer or the monomer mixture (m-2). When used in this range, the hollow polymer particles of the present invention having excellent water resistance and alkali resistance can be obtained.

As the polymerization temperature, usually 5 to 95 ° C. is good, especially
50-90 ° C is preferred.

Other chain transfer agents can be used if necessary.

Examples of the chain transfer agent include mercaptans such as t-dodecyl mercaptan, octyl mercaptan, n-tetradecyl mercaptan, octyl mercaptan, t-hexyl mercaptan, and halogen compounds such as carbon tetrachloride and ethylene bromide. .

In the emulsion polymerization of the present invention, depending on the pH of the polymerization system, polymerization stability and particle size distribution of the hollow polymer particles of the present invention,
The ratio of inside diameter / outside diameter is influenced by not a little. When the pH is lower than 7, the above items are satisfactory, and the desired hollow particles of the present invention are obtained. When the pH exceeds 7, when the monomer or the monomer mixture (m-2) does not contain a polymerizable unsaturated carboxylic acid, the above items are similarly good without any problem, but the polymerizable unsaturated carboxylic acid is contained. In such a case, the polymerization stability tends to decrease, which is not preferable.

The pre-hollow polymer particles (P) described in the aforementioned JP-A-62-12
When an aqueous dispersion of hollow fine particles obtained by the method disclosed in JP-A-7336 is used, since the pH is 7 or less, a polymer monomer to be formed on the surface of the hollow fine particles can be used without limitation, and preferable.

Thus, according to the present invention, as described above, hollow polymer particles having at least two polymer layers, (1) having an average particle size in the range of 0.15 to 20 μm, and (2) The average ratio of the relative hollow diameter to the equivalent particles is in the range of 0.2 to 0.8, (3) the proportion of the toluene-insoluble portion is 20 to 90% by weight, and (4) the conditions of 180 ° C and 10 kgf / cm ² . (5) The inner layer of the two polymer layers has the following formula (a):
Consisting of a crosslinked polymer consisting of (b), (c) and optionally (d); and (6) the outer layer of the two-layer polymer is of the formula (b)
The hollow polymer particles of the present invention are provided, which comprise a non-crosslinked polymer comprising at least one polymer unit selected from the group consisting of (c) and (d).

The average particle diameter of the hollow polymer particles (Q) of the present invention is in the range of 0.15 to 20 μm as described above. Average particle size is 0.
Those having a particle size of less than 15 μm have poor opacity when used as a light scattering aid, and those having a particle size of more than 20 μm have poor polymerization stability and generate new particles derived only from the monomer (m-2) during polymerization. However, the desired concealing properties and various physical properties such as gloss cannot be balanced.

The average particle size of the hollow polymer particles (Q) of the present invention is preferably in the range of 0.2 to 2 μm.

In addition, the average value of the ratio of the equivalent hollow diameter body equivalent particle diameter for each particle is in the range of 0.2 to 0.8.

When the ratio is less than 0.2, the concealing property is considerably poor, which is not preferable. When the ratio exceeds 0.8, the balance between the concealing property and the adhesiveness, gloss, and strength is poor, which is not preferable.

This ratio is preferably between 0.4 and 0.75. The equivalent hollow diameter means the diameter when the hollow part is converted into a sphere,
Similarly, the equivalent particle size means the particle diameter when the particles are converted into spheres. The average of these ratios is determined, for example, for 50 randomly employed particles.

In the hollow polymer particles of the present invention, the proportion of the toluene-insoluble portion is 20 to 90% by weight, preferably 20 to 80% by weight. The melt flow rate is 0.1-1g / 10min (180
° C, 10 kgf / cm ² ), preferably 0.1 to 0.8 g / 10 min.

The composition of the inner layer and the outer layer of the polymer is as described above, and the proportion thereof is preferably 5 to 2,000 parts by weight of the inner layer per 100 parts by weight of the outer layer, more preferably 10 to 2,000 parts by weight of the inner layer per 100 parts by weight of the outer layer. 1,000 parts by weight.

The outer layer preferably has a Tg of 40 to 150 ° C., and the T of the inner layer
g does not exist below 150 ° C.

Furthermore, the hollow polymer particles of the present invention have a portion that dissolves in tetrahydrofuran, and the portion has a number average molecular weight of 700 to 2 in the molecular weight distribution measured by high performance liquid chromatography as a tetrahydrofuran solution.
It is preferred that the component containing 0.000,000 be contained in an amount of 1 to 80% by weight based on the sum of the parts dissolved in tetrahydrofuran.

The hollow polymer particles of the present invention, according to the above production method,
Manufactured as an aqueous dispersion.

The solid content of the aqueous dispersion of the hollow polymer particles of the present invention is not limited, but from the viewpoint of the solid content of the blend for each application, it is usually
Preferably it is 10-65%.

Incidentally, the fact that the polymer particles of the aqueous dispersion of the hollow polymer particles of the present invention have pores can be confirmed, for example, by a transmission electron microscope or by measuring the specific gravity.

The aqueous dispersion of the hollow polymer particles obtained in the present invention can be pulverized by drying. Powdering is
The aqueous dispersion can be powdered by a commonly used powdering method. For example, spray drying at 130 to 180 ° C, in a hot air atmosphere, for example, tray drying at 50 to 70 ° C or room temperature to
Fluidized bed drying at 70 ° C. The solid content of the aqueous dispersion before drying is preferably 20% or more. The particle size of the obtained powder of the aqueous dispersion of the present invention is substantially equal to the particle size of the used aqueous dispersion.

The hollow polymer particles and the aqueous dispersion thereof of the present invention show an excellent balance in various physical properties such as concealing property, gloss, adhesiveness, water resistance, solvent resistance and heat resistance. Therefore, for example, it is useful for plastic pigment (organic resin pigment),
Therapeutic materials, paper coating materials, inks, adhesives, adhesives, primers, leather treatment agents, resin and rubber additives, carpets, breathable paints, metal coating agents, lubricants, civil engineering and building materials such as sealants, can sealing agents , Heat-sensitive recording paper overcoating agent, paper additive, etc. In addition, by utilizing the encapsulation property, it is effective to use fragrance, medicine, pesticide, dye, detergent, oil and fat, food, enzyme, liquid crystal, rust inhibitor, catalyst, flame retardant, anti-aging agent, adhesive, etc. The components can be encapsulated by means such as immersion, reduced pressure, and pressure immersion depending on the application. Depending on the useful components contained therein, it can be used for various uses such as pharmaceuticals and cosmetics.

The physical properties of the (hollow) polymer particles of the following Examples and Comparative Examples and the properties when used in a coating film were measured by the following methods.

((Method for Measuring Physical Properties of Polymer Particles)) (1) Measurement of Particle Size and Inner Pore Size: Transmission Electron Microscope (JEM-100S manufactured by JEOL Ltd.)
It was measured from an electron micrograph using X).

(2) MFT (minimum film forming temperature): Measured using a thermal gradient film forming temperature measuring device (manufactured by Rigaku Corporation).

(3) Number average molecular weight; (Sample preparation) The aqueous dispersion-shaped polymer particles are treated with an ion exchange resin (Amberlite IR120 manufactured by Organo Corporation) to adjust the pH to about 2.

Tetrahydrofuran 3 for 100 mg of polymer solids
The mixture is added at a ratio of 0 ml, and allowed to stand at room temperature for 24 hours to dissolve the polymer.

Pre-filter (AP25-, manufactured by Nippon Millipore Industry Co., Ltd.)
1000) and a microfilter (Microfilter FR-100 manufactured by FUJIFILM Corporation) to remove insoluble components, and further diluted three-fold with tetrahydrofuran as a sample.

(Measurement conditions) Measuring equipment: High-performance liquid chromatograph HLC-802A manufactured by Toyo Soda Co., Ltd. Column: TSK gel G6000S-G6000 manufactured by Toyo Soda Co., Ltd.
S-G5000HS-G4000HS-G4000HS (* in no particular order), flowing solvent: tetrahydrofuran, flow rate: 1.0 ml / min, pressure: 84 kg / cm ² , The number average molecular weight in terms of polystyrene was measured under the above conditions.

(4) Measurement of toluene-insoluble content; (Procedure) The latex is dried on a glass plate.

About 0.15 g of the dried polymer is placed in a 100 ml Erlenmeyer flask and precisely weighed. (Ag) Add 50 ml of solvent (toluene) by auto burette,
Shake at 60 ° C for 30 minutes.

The solution is filtered through Toyo Filter Paper No. 2 (JIS-P3801 type 2), and the filtrate is treated at 23,000 rpm for 1 hour in an ultracentrifuge (Hitachi 55P-2). (* At this time, the polymer not dissolved in toluene is precipitated, and the polymer dissolved in toluene is present in the clear supernatant.) 10 ml of the supernatant is collected using a whole pipette, and an aluminum dish (Bg Pour).

The solvent is evaporated and dried on a hot plate, and after cooling, the polymer content is precisely weighed together with the aluminum dish. (Cg) The solvent insoluble content is calculated from the following equation.

(5) MFR (Melt Flow Rate); (Preparation of Sample) The polymer particles in the form of an aqueous dispersion were dried and powdered on a glass plate to obtain a sample.

(Measurement conditions): Performed according to JIS K7210.

Measuring equipment: Melt indexer manufactured by Takara Kogyo Co., Ltd. Temperature: 180 ° C Load: 10kgf ((Test conditions of coating film)) (6) Opacity: Opacity test paper (made by Nippon Test Panel Kogyo) Apply with an applicator, dry at 20 ° C, 60% PH for 5 days, measure the gloss of 45 ゜ / 0 ゜ on the black and white part of the test paper with a Murakami gloss meter and use the following formula from the ratio. Calculated. (JIS K-5400) (7) 60 ° specular gloss (glass plate): After leaving the prepared sample for one day, apply it to the glass plate with a 3 mil applicator, dry it at 20 ° C and 60% RH for 5 days, and then use the Murakami gloss meter. Measured.

(8) Water resistance: The glass plate coating film prepared in (7) was dried for one day, immersed in water at room temperature for 14 days, and visually judged.

(Judgment) ：: No blistering of the coating film and no blistering.

：: No blistering of coating film, slight blistering.

Δ: The coating film is blistered and slightly blistered.

X: Large swelling of the coating film and much blistering.

(9) Solvent resistance: The glass plate coating film prepared in (7) was dried for one day, immersed in toluene at room temperature for 24 hours, and visually judged.

(Judgment) ：: blistering of coating film, no blistering.

Δ: Blistering of the coating film, slight blistering.

×: Large swelling and blistering of the coating film.

(10) Heat resistance: The glass plate coating film prepared in (7) is placed in a thermostat kept at 100 ° C., left for one day, and then placed in a room with one axis, and visually determined.

(Judgment) ：: No blistering of the coating film and no blistering.

Δ: No blistering of the coating film and blistering.

X: The coating film has blistering and blistering.

(11) Adhesion; (Adhesion) Apply the prepared paint twice to a flexible board with a brush (200 g / cm ² ), dry for 5 days, and use a razor
A square goban was made, and a peeling test was performed using cellophane tape. (JISA-6910) (12) Film strength: A 0.5 mm coating film dried for 5 days was punched with a dumbbell No. 2 and evaluated by an autograph. (20 ° C., 60% RH) [Examples] Next, the present invention will be described in more detail with reference to Examples.
This does not limit the present invention. In the following description, "%" and "part" represent% by weight and part by weight.

(1) Production of heterogeneous polymer (S): 80 parts of styrene, 17 parts of methyl methacrylate, 3 parts of methacrylic acid and 7 parts of t-dodecyl mercaptan, 200 parts of water, 0.5 part of sodium lauryl sulfate and 1.0 part of potassium persulfate
The resulting mixture was placed in a dissolved aqueous solution and polymerized at 70 ° C. for 4 hours with stirring to obtain polymer particles. The polymer particles had an average particle size of 0.2 μm and a number average molecular weight of 6,000 in terms of polystyrene by GPC. This is defined as S-1.

Production of Heterogeneous Polymers (S-2 to 7): Polymerization was carried out under the same conditions as S-1 except that polymerization was carried out with the monomer composition shown in Table 1 to obtain heterogeneous polymers of S-2 to S-7.

Production of heterogeneous polymer (S-8): 2 parts of heterogeneous polymer S-5 as a solid content is added to an aqueous solution in which 0.2 part of sodium lauryl sulfate and 0.7 part of potassium persulfate are dissolved in 200 parts of water, and the mixture is heated to 75 ° C. while stirring. After heating, 85 parts of styrene, 7 parts of methyl methacrylate, 8 parts of acrylic acid and 7 parts of t-dodecyl mercaptan were continuously added over 5 hours to carry out polymerization.
Time aging was performed. The obtained polymer particles have an average particle size of 2 μm and a number average molecular weight in terms of polystyrene by GPC.
6,500. This is designated as S-8.

The meanings of the abbreviations in Table 1 and the following tables are as follows.

DVB Divinylbenzene EDMA Ethylene glycol dimethacrylate ST Styrene AN Acrylonitrile BD Butadiene AA Acrylic acid MAA Methacrylic acid EA Ethyl acrylate BA Ethyl acrylate 2EHA 2-ethylhexyl acrylate MMA Methyl methyl methacrylate 2HEMA 2-hydroxyethyl methacrylate Acrylic ester HH DBS Sodium dodecylbenzenesulfonate POENPE Polyoxyethylene nonylphenyl ether (2) Production of pre-hollow polymer particles (P): An aqueous dispersion of a heterogeneous polymer (S-1) is used as seed polymer particles, and this polymer particle is 10 parts by solid content, 0.1 part of polyoxyethylene nonylphenyl ether, 0.3 part of sodium lauryl sulfate and 0.5 part of potassium persulfate and 39 parts of water
0 parts were charged into the reaction vessel. Methyl methacrylate 7
When a mixture of 5 parts, 20 parts of divinylbenzene (same as pure product) and 5 parts of acrylic acid was added and stirred at 30 ° C. for 1 hour, the substance was almost completely absorbed by the seed polymer particles. This was polymerized with stirring at 70 ° C. for 5 hours to obtain a dispersion of capsule particles containing water inside the particles at a polymerization yield of 99%. When this dispersion was dried and observed with a transmission electron microscope, the polymer particles were completely spherical hollow polymer particles having a transparent central portion. The hollow particles had an outer diameter of 0.40 μm and an inner diameter of 0.30 μm. This was designated as P-1.

The pre-hollow polymer particles (P) thus obtained were used as seeds in the production of the hollow polymer particles (Q) of the present invention described below.

Production of pre-hollow polymer particles (P-2 to 6,8,9,11,13): Sample numbers and amounts used in Table 2 are used as the heterogeneous polymer (S) and described in Table 2. The polymerization was carried out in the same manner as in P-1, except that 100 parts by weight of the monomer mixture consisting of the monomer composition (m-1) was used, and the amount of the emulsifier was adjusted, and P-2 to 6,8,9,11, I got 13. However,
P-5.6 is obtained by absorbing 12 parts and 13 parts of the different polymer S-2 with 10 parts of toluene and 15 parts of dibutyl phthalate, respectively, and then polymerizing them. The results of the polymerization are shown in Table 2.

Production of Pre-Hollow Polymer Particles (P-7): 2 parts of an aqueous dispersion of a heterogeneous polymer (S-8) as solids, 5 parts of polyvinyl alcohol (Gothenol GH20, manufactured by Nippon Synthetic Chemical Co., Ltd.), polymerization 3,5,5-
Trimethylhexanoyl peroxide (Perloyl 35
5, manufactured by Nippon Yushi Co., Ltd.) and 500 parts of water were charged in a reaction vessel. A mixture of 50 parts of 4-vinylpyridine, 2 parts of divinylbenzene, 28 parts of styrene, 20 parts of butyl acrylate and 100 parts of toluene was added thereto, and the mixture was stirred at 40 ° C. for 2 hours to allow the above-mentioned monomer and solvent to be absorbed by the seed polymer particles. Thereafter, polymerization was carried out with stirring at 70 ° C. for 15 hours. As a result, a dispersion of capsule particles containing toluene was obtained with a polymerization yield of 98%. The results of the polymerization are shown in Table 2.

Preparation of Pre-Hollow Polymer Particles P-10,12: P-7 except that the monomer composition and the amount of the oily substance toluene used in the method for preparing P-7 were changed to those shown in Table 1.
Polymerization was carried out in the same manner as in the above to obtain P-10,12.

Production of Hollow Polymer Particles (Q): Example 1 20 parts of solid dispersion of the aqueous dispersion of hollow particles P-1 prepared by the above method was used as seed particles, and 127 parts of water and 0.7 part of potassium persulfate were used. In the reaction vessel No. 2, the temperature was raised to 85 ° C. under a nitrogen atmosphere, and the next monomer emulsion was
It was dropped continuously over time.

Monomer emulsion: 40 parts of water, 5 parts of butyl acrylate, 89 parts of butyl methacrylate, 5 parts of methacrylic acid, 1 part of N-methylol methacrylamide and 0.3 part of sodium dodecylbenzenesulfonate. Then it was cooled.
The resulting dispersion was free of coagulated material. When the particle size of the dispersion was measured with a Nanosizer (Coulter, N-4 model), it was 0.63 μm. Drying the resulting dispersion,
Observation with a transmission electron microscope revealed that the surface of the pre-hollow polymer particles was coated with a polymer layer. The hollow particles had an outer diameter of 0.63 μm and an inner diameter of 0.30 μm. No new particles were generated, and all the particles had hollows. Table 3 shows the manufacturing requirements and results.

Examples 2, 3, 6 and Comparative Examples 1 to 5 In Example 1, some conditions were changed to those of Examples 2, 3, and
Polymerization was carried out in exactly the same manner as in Example 1 except that the conditions described in Section 6 and Comparative Examples 1 to 5 were changed.

Example 4 150 parts of water, 1.0 part of potassium persulfate, 0.4 part of sodium bisulfite, 0.5 part of sodium dodecylbenzenesulfonate, 0.1 part of polyoxyethylene nonylphenyl ether (EO = 30 mol) in a 100 stainless steel pressure vessel, Then, 40 parts of the above P-3 in terms of solid content were charged as seed particles, and the temperature was raised to 70 ° C. under a nitrogen atmosphere with stirring, and the following monomer mixture was continuously dropped over 12 hours.

A monomer mixture: 75 parts of styrene, 15 parts of 1,3-butadiene, 5 parts of methacrylic acid and 5 parts of acrylester HH Further, the mixture was aged at 80 ° C. for 5 hours after the completion of the monomer addition, and then cooled. There was no coagulated product in the obtained dispersion. The particle diameter of the dispersion was 0.55 μm, and the dried polymer particles were hollow particles having an outer diameter of 0.54 μm and an inner diameter of 0.30 μm, and no new particles were generated.

Examples 5, 7, and 8 In Example 4, some conditions were changed to those of Examples 5, 7, and 8 shown in Table 3.
Polymerization was carried out in exactly the same manner as in Example 4, except that the conditions described in column 8 were changed.

Example 9 The hollow particle aqueous dispersion P-9 was used as seed particles, and the solid content was 500 parts, water 1400 parts, sodium dodecylbenzenesulfonate 0.7 part, polyoxyethylene nonylphenyl ether (EO = 30 mol) 0.1 Parts were placed in 2 reaction vessels. A mixture of 5 parts of n-butyl acrylate, 89 parts of methyl methacrylate and 6 parts of methacrylic acid was added thereto, and the mixture was heated at 40 ° C.
For 1 hour, and the monomer mixture was almost completely absorbed by the seed hollow polymer particles. To this were added 1.0 part of benzoyl peroxide and 0.5 part of sodium bisulfite, the temperature was raised to 70 ° C., polymerization was carried out for 5 hours, and then the mixture was cooled.
There was no coagulated product in the obtained dispersion, and the dried polymer particles were hollow particles having an outer diameter of 0.41 μm and an inner diameter of 0.30 μm, and no new particles were generated.

Comparative Examples 6 and 7 The following ordinary polymer particle dispersion was used in place of the pre-hollow polymer particle (P) dispersion of Example 1, and the obtained polymer particles had a particle diameter of 0.64 μm. There was no inner hole. This is referred to as Comparative Example 6.

Seed polymer particle dispersion P'-1; aqueous dispersion produced by conventional emulsion polymerization.

 Particle size 0.40 μm, pH 7.2, solid content 40%.

The composition is butyl acrylate / methyl methacrylate / styrene / acrylic acid = 45/10/42/3, and there is no inner hole.

Comparative Example 7 was obtained by changing the kind and amount of the polymer particles of the seed in the above method to those shown in Table 3 and the following.

Seed polymer particle dispersion P'-2; aqueous dispersion produced by conventional suspension polymerization.

Particle size 4 μm, pH 7.8, solid content 45%. The composition is ethyl acrylate / styrene / acrylic acid = 20/79/1, with no internal pores.

Comparative Examples 9, 10 and 11 The hollow polymer particles of P-1 and commercially available polymer fine particles (OP-84 (P'-3) manufactured by Rohm. & Haas) and Plastic Pigment AK8801 (P'-4) manufactured by Asahi Kasei Corporation were used. Comparative examples 9 and 9, respectively
10 and 11.

Comparative Example 8 Using hollow particle aqueous dispersion P′-3 as seed particles,
200 parts of solids, 460 parts of water, 0.5 parts of potassium persulfate 2
, The temperature was raised to 85 ° C. under a nitrogen atmosphere, and the next monomer emulsion was continuously dropped for 3 hours to carry out polymerization.

Monomer emulsion: Water 40 parts Styrene 95 parts Methyl methacrylate 5 parts Sodium dodecylbenzenesulfonate 0.3 parts Polyoxyethylene nonylphenyl ether 0.1 parts After completion of the dropwise addition, the temperature was maintained for 2 hours and then cooled.
The outer diameter of the dried polymer particles is 0.62 μm and the inner diameter is 0.30 μm
And no new particles were generated.

The monomer composition of the heteropolymer (S), the monomer composition (m-1) of the pre-hollow polymer particles (P) and the monomer composition (m-2) of the hollow polymer particles (Q), and (m-2) 100
The amount of the polymerized units (a), (b), (c), and (d) defined in the claims is determined from the amounts of the pre-hollow polymer particles (P) and the heterogeneous polymer (S) used for each part. % Was calculated and described in Table 3.

[Application Examples] 60 parts by weight of each of the aqueous dispersions of Examples 1 to 9 and Comparative Examples 1 to 11, 40 parts by weight of a 71% aqueous dispersion of rutile-type titanium dioxide, and an acrylic copolymer as a binder Emulsion (JSRAE315, manufactured by Japan Synthetic Rubber Co., Ltd.)
Part, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Texanol CS-12 manufactured by Chitso Corporation) 7
, 3 parts of ethylene glycol, 2 parts of sodium salt of β-naphthalenesulfonic acid formalin condensate, 1.5 parts of hydroxyethyl cellulose, and 150 parts of water, and the mixture was stirred until the viscosity became constant. Thus, each coating composition was prepared.

Each of the above paints was applied on the Morest hiding power chart and on a glass plate, and was air-dried for 3 days without a coating having the same thickness. Table 4 shows the physical properties of these coatings.
The test conditions are as follows.

Examples 1 to 9 show excellent concealing properties, gloss, adhesion, water resistance, solvent resistance, heat resistance, and strength. For example, as compared to Comparative Examples 6 and 7 in which solid polymer particles were used for polymerization, they exhibited extremely excellent concealing properties and gloss. In addition, plastic pigments (Comparative Example-11) and commercially available hollow polymer particles (P ′) -3) (Comparative Example 10), a prototype hollow polymer particle (first hollow polymer particle (P-1)) alone (Comparative Example 9), and a two-layer weight in which neither the inner layer nor the outer layer is a crosslinked polymer. The hollow polymer particles (Comparative Example 8) composed of the union were all insufficient in concealing property, gloss, adhesion, water resistance, solvent resistance, and heat resistance.

In particular, the hollow fine particles of Examples 1 to 5 and 7 to 9 are more excellent in concealing property, gloss, water resistance and the like, and are particularly preferable and remarkable.

In Comparative Example 1, the ratio of the inner diameter / outer diameter of the polymer particles of the obtained aqueous dispersion was smaller than 0.2, and the concealing property was extremely poor, which was not preferable.

In Comparative Examples 2 and 5, the particle size of the obtained aqueous dispersion was 20 μm.
The polymerization stability is poor, new particles are generated, and the opacity, gloss, and resistance are poor.

Comparative Example 3 has a particle diameter of less than 0.15 μm,
Poor polymerization stability and generation of new particles are observed, and opacity and water resistance are remarkably poor.

In Comparative Example 4, the toluene insoluble content exceeded 90% and the MFR was
Less than 0.1 and the ratio of inner diameter / outer diameter exceeds 0.8,
The gloss and strength of the coating film are extremely poor.

Comparative Examples 6, 7, and 11 are solid polymer particles, and the concealing properties are remarkably poor.

Comparative Example 8 is a hollow polymer particle made of a non-crosslinked two-layer polymer, and has the same characteristics as Comparative Example 10 and has poor physical properties.

Comparative Example 9 is a hollow polymer particle composed of a crosslinked single-layer polymer, in which the gloss and strength of the coating film are remarkably inferior, and the other resistance is also inferior.

Comparative Example 10 is a hollow polymer particle made of a non-crosslinked single-layer polymer, and the coating film has extremely poor solvent resistance, heat resistance, and water resistance, and also has poor gloss and strength.

The hollow fine particles obtained by the method of the present invention are in the form of an aqueous dispersion, and can be used as they are, or dried,
It can also be used as a powder. Especially in the case of solvent-based paints, etc.
Powders are preferred. Drying is possible by ordinary means. For example, 5 kg of an aqueous dispersion having a solid content of about 40% is introduced using a spray dryer (Mobile Miner type spray dryer manufactured by Ashizawa Niro Atomizer Co., Ltd.) at the inlet. Temperature 130-18
2 kg of powder could be produced in 3.5 hours at 0 ° C. at a dropping rate of 1.5 kg / hr.

<Effects of the Invention> The hollow polymer particles of the present invention have the above-described unique particle structure, and are excellent in concealing property, gloss, water / solvent / heat resistance, adhesion, and coating film strength. In addition, it is used as a pigment or the like by utilizing high opacity, lightweight, and the like. For example, it can be widely used as an internal additive for paints, paper coatings, inks, carpets, papers, etc., and is useful because of the above-mentioned characteristics which could not be exhibited by ordinary hollow particles.

Further, taking advantage of the characteristics of the capsule function, it can not only contain substances such as solvents, plasticizers, fragrances, inks, agricultural chemicals, and medicines, but also has the merit of freely modifying the surface of hollow polymer particles. Therefore, at present, there is no technology for modifying the adhesive properties of commercially available hollow polymer particles, etc., and the invention which has hardly been applied has been studied more specifically in the above applications and / or various application fields. it can.

Further, according to the present invention, the hollow polymer particles are polymerized by a simple process of polymerizing in an aqueous medium, with good stability, and can be industrially produced.

 Next, preferred embodiments of the present invention will be described.

1. Hollow polymer particles (Q) having at least two polymer layers, (1) having an average particle diameter in the range of 0.15 to 20 μm, and (2) equivalent hollow diameter to equivalent particles for each particle. (3) the proportion of the toluene-insoluble portion is 20 to 90% by weight, and (4) the melt flow rate under the conditions of 180 ° C. and 10 kgf / cm ² is 0.1 to 0.8%. (5) The inner layer of the two polymer layers has the following formula (a) Wherein R ¹ is a hydrogen atom or a methyl group, X is an n-functional organic group or a bond, and n is a number of 2 or 3, provided that n R ^1s are the same And when X is a bond, n is 2; a polymerized unit represented by the following formula (b): Here, R ² is a hydrogen atom or a methyl group, and Y is a phenyl group, a phenyl group substituted by a halogen atom, an alkyl group or a vinyl group, a halogen atom, a cyano group, 18 is an alkanoyloxy group, an alkoxy group, a pyridyl, a pyridylalkyl, an aminoalkoxy or an amide group, a polymerization unit represented by the following formula (c): Here, R ³ and R ⁵ are the same or different and are a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom, a carboxyl group or a carboxylate group, and R ⁶ is a hydrogen atom and has 1 carbon atom.
An alkyl group having -18, a hydroxyalkyl group having 2-10 carbon atoms, or an organic group having at least one member selected from glycidyl, amino, cyano and a carbon-carbon double bond, or an equivalent of a base. A polymerized unit represented by the formula: and optionally, the following formula (d) Wherein R ⁷ is a hydrogen atom or a methyl group, a polymerized unit represented by the following formula: and a cross-linked polymer consisting of: (6) The outer layer of the two-layered polymer has the formula (b)
(C) A hollow polymer particle comprising a non-crosslinked polymer comprising at least one polymer unit selected from the group consisting of (d).

2. The hollow polymer particles according to 1 above, wherein the average particle type is in the range of 0.2 to 2 μm.

3.The average ratio of equivalent hollow diameter to equivalent particle size for each particle is 0.
The hollow polymer particle according to the above item 1, which is in the range of 4 to 0.75.

4. The hollow polymer particle according to 1 above, wherein the proportion of the toluene-insoluble portion is 20 to 80% by weight.

5. The hollow polymer particle according to 1 above, wherein the outer layer of the two polymer layers has a Tg of 40 to 150 ° C.

6. The hollow polymer particle according to 1 above, wherein the Tg of the inner layer of the two polymer layers does not exist at 150 ° C. or lower.

7.180 ℃, the melt flow rate conditions of 10kgf / cm ² 0.
The hollow polymer particle according to the above item 1, wherein the amount is 1 to 0.8 g / 10 min.

8. The inner layer of the two polymer layers weighs 1 to 80 parts by weight of the polymerized unit (a) based on the total of the polymerized unit (a), the polymerized unit (b), the polymerized unit (c) and the polymerized unit (d). %, 20 to 99% by weight of a hydrophilic polymerized unit selected from the polymerized unit (b) and the polymerized unit (c), and a non-hydrophilic polymerized unit and a polymerized unit of the polymerized unit (b) or the polymerized unit (c) ( The hollow polymer particles according to 1 above, which is a crosslinked polymer comprising 0 to 70% by weight of other copolymerizable polymer units selected from d).

9. The outer layer of the two-layer polymer has a polymerized unit (b) of 0 to 99.5% by weight and a polymerized unit (c) based on the total of the polymerized unit (b), the polymerized unit (c) and the polymerized unit (d). Is a non-crosslinked polymer comprising 0.5 to 100% by weight and a polymerized unit (d) of 0 to 80% by weight.

10. The outer layer of the two polymer layers is made of a non-crosslinked polymer containing 0.5 to 50% by weight of a polymerized unit of the above formula (c) wherein R ⁶ is a hydrogen atom and / or R ⁴ is a carboxyl group. The hollow polymer particle according to the above item 1, which is constituted.

11. An outer layer of the two polymer layers, wherein Y is a phenyl group or a phenyl group substituted with an alkyl group, wherein the polymer unit of the above formula (b) is contained in an amount of 20 to 99.5% by weight. The hollow polymer particles according to the above 1, which is composed of a polymer.

12.The polymer component constituting the hollow polymer particles has a portion that dissolves in tetrahydrofuran, and the portion has a number average molecular weight of 70 in the molecular weight distribution measured by high performance liquid chromatography as a tetrahydrofuran solution.
The hollow polymer particle according to the above 1, wherein the component having 0 to 20,000 is contained in an amount of 1 to 80% by weight based on the sum of the parts dissolved in tetrahydrofuran.

13.The ratio of the inner layer and the outer layer of the two polymer layers is the outer layer 1
The hollow polymer particles according to 1 above, wherein the amount of the inner layer is 5 to 2,000 parts by weight per 100 parts by weight.

14. (A) A hollow polymer comprising a crosslinked polymer comprising the polymerized units of the above formulas (a), (b), (c) and optionally (d), and having an average particle size in the range of 0.05 to 15 μm. Particle (P) and (B) The following formula (b1) Here, the definitions of R ² and Y are the same as those in the above formula (b), and a monomer represented by the following formula (c1) Here, the definitions of R ³ , R ⁴ , R ⁵ , and R ⁶ are the same as in the above formula (c), and a monomer represented by the following formula (d1): CH ₂ = CR ⁷ -CH = CH ₂ ( d1) Here, the definition of R ⁷ is the same as that of the above formula (d). At least one monomer (m-2) selected from the group consisting of monomers represented by the following formula: Combined particles (P) and monomer (m-2)
5 parts by weight or less of emulsifier per 100 parts by weight of
Alternatively, the hollow polymer particles (Q) according to 1 above, which are produced by subjecting to polymerization in an aqueous medium in the presence of a dispersant at a pH of less than 7.

15. The hollow polymer particles (P) are represented by the following formula (a1) Here, the definitions of R ¹ , X and n are the same as those of the above (a). A monomer represented by the formula, a monomer represented by the above formula (c1) and, if necessary, represented by the formula (d1) In the presence of other polymer (S) particles having a composition different from that of the copolymer from the monomer mixture, the monomer mixture (m-1) was mixed with the other monomer per 100 parts by weight of the monomer mixture. The hollow polymer particles (Q) according to the above item 14, wherein the hollow polymer particles (Q) are produced by polymerizing in an aqueous medium, using the polymer (S) particles in a proportion of 1 to 100 parts by weight.

Claims (1)

(57) [Claims] 1. Hollow polymer particles having at least two polymer layers, wherein (1) the average particle diameter is in the range of 0.15 to 20 μm, and (2) the equivalent hollow diameter of each particle versus the equivalent particle. The average diameter ratio is in the range of 0.2 to 0.8, (3) the proportion of the toluene-insoluble portion is 20 to 90% by weight, and (4) the melt flow rate under the conditions of 180 ° C. and 10 kgf / cm ² is 0.1%. (5) The inner layer of the two polymer layers has the following formula (a) Wherein R ¹ is a hydrogen atom or a methyl group, X is an n-functional organic group or a bond, and n is a number of 2 or 3, provided that n R ^1s are the same And when X is a bond, n is 2; a polymerized unit represented by the following formula (b): Here, R ² is a hydrogen atom or a methyl group, and Y is a phenyl group, a halogen atom, a phenyl group substituted with an alkyl group or a vinyl group, a halogen atom, a cyano group, a carbon number of 1 to 1. 18 alkanoyloxy groups,
An alkoxy group, pyridyl, pyridylalkyl, aminoalkoxy or amide group, a polymerized unit represented by the following formula (c): Here, R ³ and R ⁵ are the same or different and are a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom, a carboxyl group or a carboxylate group, R ⁶ is a hydrogen atom,
An alkyl group of 18 or a hydroxyalkyl group having 2 to 10 carbon atoms or glycidyl, amino, cyano and carbon-
A polymerized unit represented by the following formula (d), which is an organic group having at least one member selected from a carbon double bond, or an equivalent of a base. Wherein R ⁷ is a hydrogen atom or a methyl group, a polymerized unit represented by the following formula: and a cross-linked polymer consisting of: (6) The outer layer of the two-layered polymer has the formula (b)
Hollow polymer particles comprising a non-crosslinked polymer comprising at least one polymer unit selected from the group consisting of (c) and (d).