JP5106980B2 - Method for producing hollow resin particles - Google Patents

Description

The present invention relates to a method for producing hollow resin particles. More specifically, the present invention relates to a simple method for producing small-sized hollow resin particles.

Conventionally, as hollow resin particles, a method of obtaining hollow resin particles by performing thermal expansion after producing a heat-expandable microcapsule by suspension polymerization of a homogeneous mixture of low-boiling hydrocarbons and vinyl monomers in an aqueous medium. Is known (see, for example, Patent Document 1).

However, since the hollow resin particles obtained by heating and expanding the thermally expandable microcapsules have a heating and expanding step in the manufacturing process, it is difficult to reduce the particle diameter to about 30 μm or less.

Further, as a method for producing hollow resin particles not including a heating expansion step, a method in which a resin solution is dispersed in an aqueous dispersion of resin fine particles, a resin fine particle is formed with a solvent in the solution, and then the solvent is removed. Has been proposed (see Patent Document 2).

However, the hollow resin particles produced using resin fine particles are difficult to adjust the physical properties of the hollow resin particles because the resin in which the particles are formed and the resin derived from the dispersed resin solution coexist.

International Publication W099 / 43758 Pamphlet JP 2007-126533 A

This invention is made | formed in view of said situation, The subject of this invention is providing the manufacturing method of the hollow resin particle with a small particle size of about 30 micrometers or less.

As a result of intensive studies, the present inventors have completed the present invention.
That is, in the present invention, the solubility of the resin (B) having at least one of an isocyanate group and an epoxy group and the chain extender (C) having a group in which a reactive group that reacts with at least one of the isocyanate group and the epoxy group is blocked is increased. It is a solution dissolved in a solvent (E) having a parameter (hereinafter referred to as SP value) of 7 to 11, and the concentration of the resin (B) and the chain extender (C) is 0.1 to 0.1 based on the weight of the solution. A solution of 40% by weight was dispersed in a mixture of water and the surfactant (A), and the isocyanate group and epoxy group in the resin (B) were reacted with the reactive group in the chain extender (C). Thereafter, the aqueous dispersion (X) of the hollow resin particles (D) is obtained by removing the solvent (E) by distilling it out of the system or extracting it into water. is there.

According to the present invention, hollow resin particles having a small particle size of about 30 μm or less can be obtained by a simple process that does not particularly require a heating expansion step.

The resin (B) used in the present invention includes a resin (B1) having an isocyanate group and a resin (B2) having an epoxy group. Examples of the resin (B1) include a urethane prepolymer having an isocyanate group concentration (hereinafter abbreviated as NCO%) of 1 to 50% by weight and a urethane resin having an isocyanate group. Of these, those having NCO% of 1 to 10% by weight are preferred. The number average molecular weight of (B1) is preferably 500 to 100,000, more preferably 2,000 to 30,000.

The polyisocyanate (B11) for producing the resin (B1) is an aliphatic polyisocyanate having 2 to 12 carbon atoms (excluding carbon in the NCO group) [ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene. Diisocyanate, 2,2,4-trimethylhexane diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, etc.]; alicyclic polyisocyanate having 4 to 15 carbon atoms (excluding carbon in the NCO group) [isophorone diisocyanate , Dicyclohexylmethane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, etc.]; aromatic / aliphatic polyisocyanate having 8 to 12 carbon atoms (excluding carbon in the NCO group) [xy Range isocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.]; aromatic polyisocyanate [tolylene diisocyanate, diethylbenzene diisocyanate, diphenylmethane diisocyanate, naphthylene diisocyanate, etc.] and / or modified products thereof (carbodiimide) A diisocyanate having a group, a uretdione group, a uretoimine group and / or a urea group); and combinations of two or more thereof. The amount of polyisocyanate having 3 or more functional groups is 30% by weight or less based on diisocyanate. If necessary, polyisocyanate having 3 or more isocyanate groups can be used together with diisocyanate. The amount of the polyisocyanate used is 30% by weight or less based on the diisocyanate.

Of those exemplified as (B11), preferred are aliphatic diisocyanates and alicyclic diisocyanates, and particularly preferred are hexamethylene diisocyanate (hereinafter abbreviated as HDI), isophorone diisocyanate (hereinafter abbreviated as IPDI) and dicyclohexyl. Methane diisocyanate (hereinafter abbreviated as hydrogenated MDI).

Examples of the polyol (B12) for producing the resin (B1) having an isocyanate group include polyether polyol, polyester polyol, silicon polyol, polybutadiene polyol, fluorine-containing polyol, polymer polyol, glycidyl group-containing polyol, and mixtures thereof. . Among these, a polyester polyol is preferable, and a polyester diol having 2 hydroxyl groups is particularly preferable. If necessary, a polyol having 3 or more hydroxyl groups can be used together with the polyester diol. The amount of the polyol used is 30% by weight or less based on the diol. The number average molecular weight of (B12) is usually 100 to 10000, preferably 500 to 3000.

Examples of the polyether polyol include compounds having a structure in which an alkylene oxide is added to a compound having two or more active hydrogen atoms (for example, polyhydric alcohol, polyhydric phenol, etc.), and a mixture thereof. Among these, preferred are polyether polyols in which different types of alkylene oxides such as PO and EO are added in a block form.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, alkylene glycol such as 1,6-hexanediol, neopentyl glycol, and diol having a cyclic group (for example, And polyhydric alcohols such as those described in JP-B No. 45-1474. Examples of the polyhydric phenol include monocyclic polyhydric phenols such as pyrogallol, hydroquinone and phloroglucin; bisphenols such as bisphenol A and bisphenol sulfone. Of these, polyhydric alcohols are preferred.

Examples of the alkylene oxide include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 1,3-, 1,4 or 2,3-butylene oxide, styrene oxide, and the like. Or a combination of two or more (block or random addition). Of these, preferred is the combined use of EO and PO, more preferably in the form of block addition.

Examples of the polyester polyol include those obtained by condensation polymerization of low molecular weight polyols and polycarboxylic acids, those obtained by ring-opening polymerization of lactones, mixtures of two or more of these, and mixed modified products.

Examples of the low molecular polyol include aliphatic low diols [ethylene glycol, diethylene glycol, propylene glycol and the like]; diols having a cyclic group [for example, those described in JP-B No. 45-1474: 1,4-bis ( Hydroxymethyl) cyclohexane, m- or p-xylylene glycol and the like] and combinations of two or more thereof.

Specific examples of the polycarboxylic acid include aliphatic dicarboxylic acids (succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, maleic acid, fumaric acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.) And combinations of two or more of these.

Examples of the lactone include γ-butyrolactone and ε-caprolactone.

The resin (B2) having an epoxy group used in the present invention is not particularly limited as long as it has two or more epoxy groups in the molecule. A preferable resin (B2) having an epoxy group is one having 2 to 6 epoxy groups in the molecule from the viewpoint of the mechanical properties of the cured product. The epoxy equivalent (molecular weight per epoxy group) of the resin (B2) having an epoxy group is preferably 65 to 1,000, and more preferably 90 to 500. When the epoxy equivalent is 1,000 or less, the cross-linked structure is dense and physical properties such as water resistance, chemical resistance and mechanical strength of the cured product are improved. The number average molecular weight of (B2) is preferably 500 to 100,000, more preferably 2,000 to 30,000.

Examples of the resin (B2) having an epoxy group include aromatic polyepoxy compounds, heterocyclic polyepoxy compounds, alicyclic polyepoxy compounds, and aliphatic polyepoxy compounds. Examples of the aromatic polyepoxy compounds include glycidyl ethers and glycidyl ethers of polyhydric phenols, glycidyl aromatic polyamines, and glycidylates of aminophenols. Examples of glycidyl ethers of polyphenols include bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, bisphenol B diglycidyl ether, bisphenol AD diglycidyl ether, bisphenol S diglycidyl ether, halogenated bisphenol A diglycidyl, and tetrachlorobisphenol A. Diglycidyl ether, catechin diglycidyl ether, resorcinol diglycidyl ether, hydroquinone diglycidyl ether, pyrogallol triglycidyl ether, 1,5-dihydroxynaphthalene diglycidyl ether, dihydroxybiphenyl diglycidyl ether, octachloro-4,4'-dihydroxybiphenyldi Glycidyl ether, tetramethylbiphenyl diglycidyl ester Ter, dihydroxynaphthylcresol triglycidyl ether, tris (hydroxyphenyl) methane triglycidyl ether, dinaphthyltriol triglycidyl ether, tetrakis (4-hydroxyphenyl) ethanetetraglycidyl ether, p-glycidylphenyldimethyltolylbisphenol A glycidyl ether, trismethyl -Tret-butyl-butylhydroxymethane triglycidyl ether, 9,9'-bis (4-hydroxyphenyl) furorange glycidyl ether, 4,4'-oxybis (1,4-phenylethyl) tetracresol glycidyl ether, 4 , 4′-oxybis (1,4-phenylethyl) phenylglycidyl ether, bis (dihydroxynaphthalene) tetraglycidyl ether, Of glycol ether of enolic or cresol novolak resin, glycidyl ether of limonene phenol novolak resin, diglycidyl ether obtained from the reaction of 2 mol of bisphenol A and 3 mol of epichlorohydrin, phenol and glyoxal, glutaraldehyde, or formaldehyde Examples thereof include polyglycidyl ethers of polyphenols obtained by condensation reactions, polyglycidyl ethers of polyphenols obtained by condensation reactions of resorcin and acetone, and the like. Examples of the glycidyl ester of polyhydric phenol include diglycidyl phthalate, diglycidyl isophthalate, and diglycidyl terephthalate. Examples of the glycidyl aromatic polyamine include N, N-diglycidylaniline, N, N, N ′, N′-tetraglycidylxylylenediamine, N, N, N ′, N′-tetraglycidyldiphenylmethanediamine and the like. Furthermore, in the present invention, the aromatic system is obtained by reacting a polyol with the above-mentioned two reactants, such as triglycidyl ether of p-aminophenol, tolylene diisocyanate or diglycidyl urethane compound obtained by addition reaction of diphenylmethane diisocyanate and glycidol. The glycidyl group-containing polyurethane (pre) polymer and an alkylene oxide (ethylene oxide or propylene oxide) adduct of bisphenol A are also included. Heterocyclic polyepoxy compounds include trisglycidyl melamine; alicyclic polyepoxy compounds include vinylcyclohexene dioxide, limonene dioxide, dicyclopentadiene dioxide, bis (2,3-epoxycyclopentyl). Ether, ethylene glycol bisepoxy dicyclopentyl ale, 3,4-epoxy-6-methylcyclohexylmethyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, bis (3,4-epoxy-6-methylcyclohexyl) Methyl) adipate, and bis (3,4-epoxy-6-methylcyclohexylmethyl) butylamine, dimer acid diglycidyl ester, and the like. The alicyclic group also includes a hydrogenated product of the aromatic polyepoxide compound; examples of the aliphatic polyepoxy compound include polyglycidyl ethers of polyvalent aliphatic alcohols and polyglycidyl esters of polyvalent fatty acids. Body, and glycidyl aliphatic amines. Polyglycidyl ethers of polyhydric aliphatic alcohols include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol Diglycidyl ether, polytetramethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether and polyglycerol polyglycidyl ether Can be mentioned. Examples of polyglycidyl ester of polyvalent fatty acid include diglycidyl oxalate, diglycidyl malate, diglycidyl succinate, diglycidyl glutarate, diglycidyl adipate, diglycidyl pimelate and the like. Examples of the glycidyl aliphatic amine include N, N, N ′, N′-tetraglycidylhexamethylenediamine. In the present invention, the aliphatic type also includes a (co) polymer of diglycidyl ether and glycidyl (meth) acrylate. Of these, preferred are aliphatic polyepoxy compounds and aromatic polyepoxy compounds. The resin (B2) having an epoxy group of the present invention may be used in combination of two or more.

The blocked reactive group of the chain extender (C) used in the present invention is dissociated by reaction with water and reacts with an isocyanate group or an epoxy group. The chain extender (C) is a compound having two or more active hydrogen groups, in which the active hydrogen groups are blocked (blocked). For example, a blocked product of carboxylic acid, amine, amine polyol, alkanolamine Is mentioned. Of these, amines are preferably blocked. If necessary, a blocked product having three or more active hydrogen groups can be used. In this case, the amount of the blocked product having 3 or more active hydrogen groups is preferably 30% by weight or less of the blocked product having 2 active hydrogen groups.

Block amines used in the present invention include ketimine type, oxazolidine type, enamine type, aldimine type, and mixtures thereof. Of these, ketimine type and oxazolidine type are preferable.

Examples of the blocking agent for blocking the polyamine include ketone compounds such as acetone, methyl ethyl ketone (hereinafter abbreviated as MEK), methyl isobutyl ketone (hereinafter abbreviated as MIBK), and the like. Of these, acetone and MEK are preferred.

A method for blocking the polyamine is not particularly limited, and a known method may be used. For example, a method of heating a mixture of a diamine and a ketone compound and removing generated water can be exemplified.

Examples of the polyamine used for the block amine include aromatic diamine [diethyltoluenediamine, 2,4 or 2,6-dimethylthiotoluenediamine, etc.], alicyclic diamine [4,4′-diamino-3,3′-. And dimethyldicyclohexylmethane, 4,4′-diamino-3,3′-dimethyldicyclohexyl, diaminocyclohexane, isophoronediamine, etc.] and aliphatic diamines [1,2-ethylenediamine, 1,6-hexanediamine]. Of these, preferred are alicyclic diamines.

Examples of the carboxylic acid blocking agent include alkyl vinyl ether [methyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether and the like] and allyl ether. Of these, vinyl ether is preferred.

Examples of amine-based polyol and alkanolamine blocking agents include organic acids [formic acid, acetic acid, propionic acid, lactic acid and the like].

The amount of the chain extender (C) used in the present invention is usually 0.5 to 1.5 equivalents, preferably 1 to 1 equivalent of the isocyanate group or epoxy group of the resin (B) having at least one of an isocyanate group and an epoxy group. Is 0.7 to 1.2 equivalents. Outside this range, a resin powder having good mechanical properties cannot be obtained.

The solubility parameter (hereinafter referred to as SP value) of the solvent (E) used in the present invention is 7 to 11, and preferably 8 to 10.5. Since the hydrophilicity is low when the SP value is less than 7, it is difficult to distill the solvent (E) out of the system or extract it into water, which is an operation for obtaining the aqueous dispersion (X). When the ratio exceeds 11, the hydrophobicity is low, and the dispersibility of the mixture of water and the surfactant (A) in the mixture becomes poor.
In addition, SP value is described in Polymer Engineering and Science, February, 1974, Vol. 14, no. 2, P.I. It is a value calculated by the Fedors method described in 147 to 154 and can be expressed by the following equation.
SP value (δ) = (ΔH / V) ^1/2
In the formula, ΔH represents the heat of vaporization (cal), and V represents the molar volume (cm ³ ).
ΔH and V are the sum of the heat of molar evaporation (ΔH) of the atomic group described in “POLYMER ENGINEERING AND SCIENCE, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. The total molar volume (V) can be used.
Those having a close numerical value are easy to mix with each other (high compatibility), and those having a close numerical value are indices that indicate that they are difficult to mix.

Specific examples of the solvent (E) include aromatic hydrocarbon solvents such as toluene, xylene and ethylbenzene; aliphatic or alicyclic hydrocarbon solvents such as n-hexane and n-heptane; ethyl acetate and butyl acetate. And ester solvents such as diethyl ether and tetrahydrofuran; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and a mixture of two or more of these solvents. Of these, toluene, xylene, and ethyl acetate are preferred.

The surfactant (A) used in the present invention is not particularly limited, but is preferably one that functions as a protective colloid from the viewpoint of dispersion stability.

The surfactant (A) functioning as a protective colloid is composed of a part (A1) having affinity with the resin (B) and a part (A2) having hydrophilicity, and (A1) and (A2) The bonding form is not particularly limited, but ester bonds and urethane bonds are preferable, and urethane bonds are particularly preferable. For example, the surfactant (A) can be prepared by heating the compound constituting (A1), the compound constituting (A2) and the diisocyanate, or dicarboxylic anhydride while mixing and stirring.

The compound constituting (A1) preferably has the same or similar structure as that used in the resin (B), and the number average molecular weight is usually 500 to 10,000.

As the compound constituting (A1), those having an SP value of usually 8 to 12 can be used, and those having an SP value difference of 0.5 or less from the resin (B) are particularly preferred.

The compound constituting (A2) is a polyoxy having a number average molecular weight of usually 500 to 10,000, preferably 1,000 to 6,000 containing oxyethylene units of usually 30% by weight or more, preferably 50% by weight or more. An alkylene glycol is mentioned. Specifically, polyethylene glycol, polyoxyethylene propylene glycol, polyethylene glycol PO (propylene oxide), EO (ethylene oxide) random adduct (the ratio of PO and EO is 80/20 to 20/80 in weight ratio) and the like. It is done. Among these, polyethylene glycol, polyethylene glycol PO, and EO random adduct are preferable.

The ratio of (A1) to (A2) is preferably 20/80 to 80/20, more preferably 30/70 to 70/30, by weight.

When the resin (B) is a resin having an isocyanate group, specific examples of the preferred surfactant (A) (A1) include, for example, polyethylene adipate diol (SP value = 10.9), polyethylene butylene adipate diol (SP value). = 10.7), PO2 molar adduct of bisphenol A and a condensation polymer of terephthalic acid (SP value = 10.1), polycaprolactone diol (SP value = 10.2), and the like.

When the resin (B) is a resin having an epoxy group, specific examples of (A1) of the preferred surfactant (A) include, for example, polypropylene glycol (SP value = 8.7), polytetramethylene ether diol (SP value). = 9.0), polyhexamethylene polycarbonate diol (SP value = 9.8), and the like.

The total concentration of the resin (B) and the chain extender (C) in the solvent (E) solution based on the weight of the solution is 0.1 to 40% by weight, and preferably 3 to 35% by weight. When the concentration exceeds 40% by weight, the hollow resin particles hardly form a hollow shape, and when the concentration is less than 0.1% by weight, the shell strength of the hollow resin particles becomes weak.

When the solvent (E) solution of the resin (B) and the chain extender (C) is dispersed in the mixture of water and the surfactant (A), the temperature during dispersion is preferably 0 to 150 ° C., more preferably Is 5-40 ° C. The pressure is preferably 0 to 1 MPa, more preferably 0 to 0.3 MPa.

The dispersion method of the solvent (E) solution of the resin (B) and the chain extender (C) in the mixture of water and the surfactant (A) is not particularly limited, and is a low-speed shearing type, a high-speed shearing type, a friction type. Known equipment such as a high-pressure jet type and an ultrasonic type can be used. Among these, a preferable one is a high-speed shearing type. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1,000 to 30,000 rpm, preferably 2,000 to 10,000 rpm. The dispersion time is not particularly limited, but is usually 0.1 to 5 minutes.

The reaction temperature and reaction time of the resin (B) and the chain extender (C) are not particularly limited, but the preferred reaction temperature is 0 to 80 ° C, more preferably 20 to 60 ° C. The preferred reaction time is 1 hour to 40 hours, more preferably 5 hours to 20 hours.

As a method for removing the solvent (E) by distilling out of the system or extracting it in water, for example, the following [1] to [3] and a combination thereof can be applied.
[1] A method of removing a solvent by heating and / or reducing pressure in a general stirring / desolving tank or a film evaporator. The degree of decompression (gauge pressure) during decompression is preferably −0.03 MPa or less, more preferably −0.05 MPa or less.
[2] A method of removing the solvent by blowing an inert gas on the liquid surface or in the liquid.
[3] A method in which the aqueous dispersion produced up to the third step is diluted with an aqueous medium, and (E) is extracted into a water continuous phase.
Of these, the method [1] is preferred.

The time for removing the solvent (E) is preferably within 48 hours, more preferably within 36 hours, and most preferably within 30 hours from the viewpoint of productivity.

The residual amount of the solvent (E) is preferably 10% by weight or less, more preferably 8% by weight or less, most preferably 5% by weight or less based on the aqueous dispersion (X).

The hollow resin particles (D) can be taken out by removing the aqueous medium from the aqueous dispersion (X).
The method for removing the aqueous medium is not particularly limited, and for example, a filtration method, a centrifugation method, a freeze-drying method, and the like can be applied.
Moreover, in order to dry the obtained hollow resin particle (D), it can carry out using well-known facilities, such as a circulating air dryer, a spray dryer, and a fluidized bed type dryer.

The volume average particle diameter D _D of the hollow resin particles of the present invention (D) is preferably not 0.1μm or 50μm or less, and more preferably from the viewpoint of stability as a powder 0.3μm or more, more preferably 0 From the viewpoint of the stability of the hollow structure, it is preferably 45 μm or less, more preferably 40 μm or less.
In addition, [volume average particle diameter] / [number average particle diameter], which is an index indicating the width of the particle size distribution of (D), is preferably 1.0 to 1.3 from the viewpoint of powder flowability, and preferably 1.0 to 1.3. 1.2 is more preferable.
The volume average particle diameter DV _D and the number average particle diameter DN _D of the resin particles (D) are flow type particle image analyzers, for example, FPIA-2100 manufactured by Sysmex Corporation, and the sample is, for example, an aqueous dispersion (X). It can be measured using a solution diluted with ion-exchanged water.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this. Hereinafter, unless otherwise specified, “parts” means “parts by weight” and% means% by weight.

The characteristic value measurement method is as follows.

<Volume average particle diameter>
The volume average particle size and particle size distribution were measured using a flow particle image analyzer under the following conditions.
Apparatus: FPIA-3000 manufactured by Sysmex Corporation
Measurement range: 0.5 μm to 200 μm

<Specific gravity>
Accurately measure 0.1 g of hollow resin particles (D) in a 10 ml graduated cylinder, and put ion exchange water in the container so that the total amount becomes 10 ml. At that time, the weight of the ion-exchanged water is measured and the specific gravity is calculated by the following formula.

<Molecular weight>
When measuring the molecular weight, the gel permeation chromatography was used under the following conditions.
Apparatus: HLC-8120 manufactured by Tosoh Corporation
Column: Two TSK GEL GMH6 [manufactured by Tosoh Corporation]
Measurement temperature: 40 ° C
Solution injection volume: 100 μL
Detection device: Refractive index detector reference material: Standard polystyrene

<Production example 1> Production of resin having isocyanate group (B1-1) Polyhexamethylene isophthalate diol (Mn2,000, dimethylsilicone) modified with hydroxyl groups at both ends of dimethylsilicone in a reaction vessel equipped with a stirring bar and a thermometer. Hydroxyl number 56) 171.4 parts were added, and dehydration was performed by heating to 120 ° C. under a reduced pressure of 3 mmHg for 2 hours. Subsequently, 28.6 parts of isophorone diisocyanate (hereinafter referred to as IPDI) and 350 parts of tetrahydrofuran were added, the reaction was carried out at 110 ° C. for 10 hours, and a resin having an isocyanate group with an isocyanate group content of 1.8% (B1- 1) 200 parts were synthesized. The number average molecular weight of (B1-1) was 4700.

<Production Example 2> Production of Resin (B2-1) Having Epoxy Group In a reaction vessel equipped with a stirring bar and a thermometer, 40 parts of glycidyl methacrylate, 63 parts of methyl methacrylate, 136 parts of styrene, a polymerization initiator azobisisobuty A mixture of 0.1 part of nitrile and 500 parts of xylene was reacted at 80 ° C. for 3 hours in a nitrogen atmosphere, and a resin having an epoxy group content of 6.1% and a number average molecular weight of 3940 (B2- 1) 200 parts were synthesized. The epoxy equivalent of (B2-1) was 655.

<Production Example 3> Production of diketimine compound (C-1) In a reaction vessel equipped with a stirring bar and a thermometer, 54 parts of isophoronediamine (hereinafter referred to as IPDA), 46 parts of methyl ethyl ketone (hereinafter referred to as MEK), and After adding 200 parts of normal hexane and reacting at 70 ° C. for 10 hours, water was removed by liquid separation to obtain a diketimine compound [chain extender (C-1)] composed of one IPDA molecule and two MEK molecules.

<Production Example 4> Production of dioxazolidine compound (C-2) In a reaction vessel equipped with a stirring bar and a thermometer, 47 parts of IPDI and 2-isopropyl-3- (2-hydroxyethyl) 1,3-oxazolidine 53 And 200 parts of normal hexane were charged and reacted at 70 ° C. for 10 hours to obtain a dioxazolidine compound [chain extender (C-2)].

<Production Example 5> Production of surfactant (A-1) In a four-necked flask equipped with a stirring bar and a thermometer, 787 parts of polycaprolactone diol (SP value = 10.2) (molecular weight 2000), polyether diol 800 parts (molecular weight 4000, EO content 50% by weight, PO content 50% by weight) were charged and dehydrated under reduced pressure at 120 ° C. The water content after dehydration was 0.05%. Subsequently, 55.5 parts of HDI, 65.5 parts of hydrogenated MDI, and 0.6 parts of dibutyltin dilaurate were added and reacted at 80 ° C. for 5 hours to obtain a surfactant (A-1).

<Production Example 6> Production of surfactant (A-2) In a four-necked flask equipped with a stirring bar and a thermometer, 787 parts of polyhexamethylene polycarbonate diol (SP value = 9.8) (molecular weight 2000), poly 800 parts of ether diol (molecular weight 4000, EO content 50% by weight, PO content 50% by weight) were charged and dehydrated under reduced pressure at 120 ° C. The water content after dehydration was 0.05%. Subsequently, 55.5 parts of HDI, 65.5 parts of hydrogenated MDI, and 0.6 part of dibutyltin dilaurate were added and reacted at 80 ° C. for 5 hours to obtain a surfactant (A-2).

<Example 1> Production of hollow resin particles 95.1 parts of resin (B1-1) having an isocyanate group in a beaker, 4.9 parts of chain extender diketimine compound (C-1), solvent xylene (E-1) (SP value 8.8) 270 parts were mixed and dissolved to obtain a solution (L-1). The total concentration based on the weight of the solution (L-1) of (B1-1) and (C-1) was 27.0%. The solution (L-1) is added to 1616 parts of water in which 80 parts of the surfactant (A-1) is dissolved, and an ultradisperser (manufactured by Yamato Kagaku) is used at 25 ° C. for 1 minute at 9,000 rpm. After mixing and dispersing, the reaction was carried out at 70 ° C. for 12 hours.
The dispersion was desolvated with a film evaporator at a reduced pressure of −0.05 MPa (gauge pressure), a temperature of 40 ° C., and a rotation speed of 100 rpm for 30 minutes, and then classified. Next, it was dried in a dryer at 40 ° C. for 1 hour to obtain hollow resin particles (D-1) of the present invention. Moreover, said evaluation was performed and the result was shown in Table 1.

<Example 2>
In a beaker, 0.9 part of resin (B1-1), 0.1 part of chain extender diketimine compound (C-2), 1000 parts of solvent pentane (E-2) (SP value 7.0) are mixed and dissolved. Solution (L-2) was obtained. The total concentration based on the weight of the solution (L-2) of (B1-1) and (C-2) was 0.1%. The solution (L-2) is added to 3500 parts of water in which 120 parts of the surfactant (A-1) is dissolved, and an ultradisperser (manufactured by Yamato Kagaku) is used at 25 ° C. for 1 minute at 9,000 rpm. After mixing and dispersing, the reaction was carried out at 70 ° C. for 12 hours.
The dispersion was desolvated with a film evaporator at a reduced pressure of −0.05 MPa (gauge pressure), a temperature of 40 ° C., and a rotation speed of 100 rpm for 30 minutes, and then classified. Next, it was dried in a dryer at 40 ° C. for 1 hour to obtain hollow resin particles (D-2) of the present invention. Moreover, said evaluation was performed and the result was shown in Table 1.

<Example 3>
In the beaker, 84.4 parts of resin resin (B2-1) having an epoxy group, 15.6 parts of diketimine compound (C-1), 150 parts of solvent pentane (E-2) (SP value 7.0) are mixed. And dissolved to obtain a solution (L-3). The total concentration based on the weight of the solution (L-3) of (B2-1) and (C-1) was 40%. The solution (L-3) is added to 1600 parts of water in which 80 parts of the surfactant (A-2) is dissolved, and an ultradisperser (manufactured by Yamato Kagaku) is used at 25 ° C. for 1 minute at a rotation speed of 9,000 rpm. After mixing and dispersing, the reaction was carried out at 70 ° C. for 12 hours.
The dispersion was desolvated with a film evaporator at a reduced pressure of −0.05 MPa (gauge pressure), a temperature of 40 ° C., and a rotation speed of 100 rpm for 30 minutes, and then classified. Next, it was dried in a dryer at 40 ° C. for 1 hour to obtain hollow resin particles (D-3) of the present invention. Moreover, said evaluation was performed and the result was shown in Table 1.

<Example 4>
In a beaker, 0.8 part of the resin (B2-1), 0.1 part of the diketimine compound (C-2) and 1000 parts of the solvent methyl cellosolve (E-3) (SP value 11) are mixed and dissolved to obtain a solution (L -4) was obtained. The total concentration based on the weight of the solution (L-4) of (B2-1) and (C-2) was 0.1%. The solution (L-4) is added to 4000 parts of water in which 200 parts of the surfactant (A-2) is dissolved, and an ultradisperser (manufactured by Yamato Kagaku) is used at 25 ° C. for 1 minute at 9,000 rpm. After mixing and dispersing, the reaction was carried out at 70 ° C. for 12 hours.
The dispersion was desolvated with a film evaporator at a reduced pressure of −0.05 MPa (gauge pressure), a temperature of 40 ° C., and a rotation speed of 100 rpm for 30 minutes, and then classified. Next, it was dried in a dryer at 40 ° C. for 1 hour to obtain hollow resin particles (D-4) of the present invention. Moreover, said evaluation was performed and the result was shown in Table 1.

<Example 5>
In a beaker, 78.3 parts of resin (B2-1), 21.7 parts of diketimine compound (C-2), 150 parts of solvent methyl cellosolve (E-3) (SP value 11) are mixed and dissolved to obtain a solution (L -3) was obtained. The total concentration based on the weight of the solution (L-3) of (B2-1) and (C-1) was 40%. The solution (L-3) is added to 1550 parts of water in which 80 parts of the surfactant (A-2) is dissolved, and an ultradisperser (manufactured by Yamato Kagaku) is used at 25 ° C. for 1 minute at a rotation speed of 9,000 rpm. After mixing and dispersing, the reaction was carried out at 70 ° C. for 12 hours.
The dispersion was desolvated with a film evaporator at a reduced pressure of −0.05 MPa (gauge pressure), a temperature of 40 ° C., and a rotation speed of 100 rpm for 30 minutes, and then classified. Next, it was dried in a dryer at 40 ° C. for 1 hour to obtain hollow resin particles (D-5) of the present invention. Moreover, said evaluation was performed and the result was shown in Table 1.

<Comparative Example 1>
120 parts by weight of deionized water, 21.6 parts by weight of 20% colloidal silica aqueous solution, 1.0 part by weight of adipic acid-diethanolamine condensate and 42 parts by weight of sodium sulfate were uniformly mixed, and then 39.5 parts by weight of acrylonitrile. Part (745 mmol), methyl methacrylate (10 parts by weight) (100 mmol), n-pentane (13 parts by weight) and azobisisobutyronitrile (0.2 parts by weight) were added, and a homomixer (ROBOMICS, manufactured by Special Machinery Co., Ltd.) was added. (4000 rpm) for 2 minutes to obtain a suspension. This suspension was transferred to a pressure-resistant reaction vessel and polymerized at a gauge pressure of 0.25 MPa and 60 ° C. for 20 hours. Subsequently, after classification, it was dried in a dryer at 40 ° C. for 1 hour. Furthermore, a heating expansion process was performed in an electric furnace at 100 ° C. for 30 minutes to obtain comparative hollow resin particles (R-1). The volume average particle diameter and specific gravity were evaluated, and the results are shown in Table 1.

According to the present invention, it has been found that hollow resin particles having a small particle size of about 30 μm or less and a low specific gravity can be obtained by a simple process that does not require a heat expansion step that requires a large amount of energy.

The resin particles produced by the method for producing hollow resin particles of the present invention can be widely used in applications such as general-purpose resin fillers, paint additives, and electronic parts.

Claims (3)

The resin (B) having at least one of an isocyanate group and an epoxy group, and the chain extender (C) having a group in which a reactive group that reacts with at least one of the isocyanate group and the epoxy group is blocked have a solubility parameter of 7 to A solution in which the total concentration of the resin (B) and the chain extender (C) is 0.1 to 40% by weight based on the weight of the solution, water and an interface After dispersing in the mixture of the activator (A) and reacting the isocyanate group and epoxy group in the resin (B) with the reactive group in the chain extender (C), the solvent (E) is left outside the system. A method for producing hollow resin particles, characterized in that an aqueous dispersion (X) of hollow resin particles (D) is obtained by removal or extraction into water. The production method according to claim 1, wherein the blocked group of the chain extender (C) is dissociated into a reactive group that reacts with an isocyanate group or an epoxy group by reaction with water. The production method according to claim 1 or 2, wherein the chain extender (C) is a block amine.