JPH0776624A - Polyester particle - Google Patents

Abstract

PURPOSE:To provide a crosslinked polyester particle containing a specific crosslinked resin as a main component, having a specific volume-average particle diameter and a specific porosity, low in specific gravity and dielectric constant, excellent in masking property, light scattering property, heat resistance and solvent resistance, and useful as a delustering agent, etc. CONSTITUTION:This crosslinked polyester particle contains a crosslinked resin as a main component and has a volume-average particle diameter D of 0.5-100mum, single or plural opened pores filled with a gas or liquid in the particle, and a porosity of 1-99vol.%. The crosslinked resin is obtained by polymerizing 5-99wt.% a vinylic monomer with 1-95wt.% of a polyester resin which is obtained by the polycondensation of a multibasic carboxylic acid component, such as terephthalic acid, containing >=50mol.% of an unsaturated multibasic carboxylic acid such as maleic acid and which has ionic groups (e.g. metal sulfonate groups) in an amount of 20-200eq./ton.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a matting agent, an anti-blocking material, a chromatography carrier, a drug carrier, a powder coating material, a gap adjusting material, an electrophotographic toner, an electrorheological fluid, cosmetics and the like. The present invention relates to resin particles that have been actively used as the above, and particularly to polyester resin particles having a large number of small holes inside the particles.

[0002]

2. Description of the Related Art Conventionally, as resin particles used for such purposes, particles obtained by "polymerization granulation method" such as emulsion polymerization method, suspension polymerization method, seed polymerization method and dispersion polymerization method have been used. Has been. However, the resin particles obtained by the emulsion polymerization method and the suspension polymerization method have a limited particle diameter range and a broad particle diameter distribution. The resin particles obtained by the seed polymerization method and the dispersion polymerization method have a sharp particle size distribution, but are very expensive. Further, the above-mentioned "polymerization granulation method", that is, the resin particles produced by emulsion polymerization, suspension polymerization, seed polymerization, and dispersion polymerization are, as is obvious from the production method, a vinyl-based polymer. Limited to resin particles. Polyester binders widely used for paints, adhesives, etc. have excellent adhesiveness to highly versatile polyester films, but the particles of the vinyl polymer described above do not always match the polyester binder. Therefore, resin particles that replace them have been desired. The inventors of the present invention are resin particles that are made of a polyester resin that is a condensation polymer and that have an arbitrary average particle size and have a sharp particle size distribution and that can be produced on an industrial scale. As Japanese Patent Laid-Open No. 3-2124
I have proposed 44 etc. According to the invention, the polyester resin contains a predetermined amount of ionic groups, and after the polyester resin is microdispersed in an aqueous medium, the dispersion stability of the microdispersion in water is controlled to allow slow agglomeration to give an arbitrary particle diameter, It is intended to obtain particles having a sharp particle size distribution.
Such polyester particles are unique such as matting agents, additives for coatings such as anti-blocking materials, and the like, which have characteristics such as good matching with polyester binders, but applications in which concealability is required, It was unsatisfactory in applications requiring light scattering properties and applications requiring low specific gravity.

Conventionally, resin particles having small pores inside have been used in applications requiring concealing properties, light scattering properties, low specific gravity, heat insulating properties, light weight properties and the like. As a method for producing resin particles having such inner pores, 1) a method in which a foaming agent is contained in the resin particles and then the foaming agent is foamed. 2) A method of encapsulating a volatile substance such as butane in a resin and then gasifying and expanding the volatile substance. 3) A method in which the resin is melted, and a gas jet such as air is blown onto this to enclose air bubbles. 4) A method in which an alkali-swelling substance is contained in the resin particles and an alkaline liquid is allowed to penetrate into the resin particles to expand the alkali-swelling substance. Etc. are known.

[0004]

However, in any of these methods, it is difficult to control the conditions and the like, and it is difficult to efficiently and reliably produce resin particles having desired inner pores. Further, according to these methods, the resin constituting the particles is required to have a certain degree of softness and thermoplasticity, so that hollow particles can be obtained with a resin that can be used for an application that naturally requires heat resistance. It is difficult. Further, like general resin particles, this method is mainly applied to resin particles of vinyl polymer, and it is difficult to apply it to condensation polymer. As described above, according to the conventional technique, the resin particles having pores inside are limited to vinyl-based polymers, and the heat resistance is poor.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies in view of the above situation, and as a result, arrived at the next invention.
That is, the present invention is obtained by condensing a polyvalent carboxylic acid component containing 5 mol% or more of an unsaturated polyvalent carboxylic acid and a polyvalent alcohol component, and has 20 to 2000 eq. / To
Polyester resin 1 containing an ionic group in the range of n 1
95% by weight of a vinyl-based monomer is contained in an amount of 5 to 99% by weight, and then a crosslinked resin obtained by polymerization is used as a main component, and a volume average particle diameter D is in the range of 0.5 to 100 μm. There are single or multiple independent pores filled with gas or liquid, and the porosity is 1 to 99 vol%
The crosslinked polyester particles are characterized in that

The particles of the present invention have a volume average diameter D of 0.5 to 1
It is essential that the range is 00 μm, and 1 to 50 μm
Is more preferable, the range of 2 to 25 μm is more preferable, the range of 2 to 15 μm is still more preferable, and the range of 2 to 9 μm is still further preferable. If the volume average diameter is less than this range, it becomes difficult to handle particles, and if it exceeds this range, it is not practical as an additive for paints. The particle size distribution of the particles of the present invention is such that particles having a particle size range of 0.5D to 2.0D are 7
It is desirable to occupy 0 wt% or more, preferably 80 wt
% Or more, 85% by weight or more, 90% by weight or more
It is preferable to occupy the above. According to another expression,
The particle size range occupied by 70 wt% or more is 0.6D to 1.8D
Is more preferable, the range of 0.7D to 1.5D is further preferable, the range of 0.8D to 1.3D is still more preferable, and the range of 0.9D to 1.2D is still further preferable. The coefficient of variation, which is the value obtained by dividing the standard deviation by the average value, is desirably 30% or less, preferably 20%.
Or less, more preferably 15% or less, and even 10
% Or less is preferable.

The particles of the present invention have single or a plurality of independent pores inside the particles. In the present invention, it is essential that the porosity is in the range of 1 to 99 vol% in any case. Here, the porosity is a value obtained by dividing the internal pore volume of the particle by the apparent volume of the particle. Porosity is 2-98 vo
a range of l% is preferred, more preferably 5 to 95 vol%, even more preferably 10 to 95 vol%, still more 20 to 90%.
The range of vol% is preferable. Such pores are filled with a gas or a liquid, the gas is preferably air, nitrogen, carbon dioxide or the like, and the liquid is preferably water. The particles of the present invention are not particularly limited thereto, but when dried, that is, when the pores are filled with gas, the apparent specific gravity is preferably in the range of 0.1 to 1.3, and further 0 The range of 0.2 to 1.2 is more preferable, and the range of 0.5 to 1.0 is more preferable.

The particles of the present invention are polyester resins 1-95.
The main component is a cross-linked resin obtained by polymerizing 5% by weight to 99% by weight of a vinyl monomer, and then polymerizing. Polyester resin here is 10-9 of all resin components.
Use of 0 wt% is preferred, 20-80 wt% or more is more preferred, and use of 30-70 wt% is still more preferred. The polyester resin in the present invention comprises polyvalent carboxylic acids and polyvalent alcohols. Examples of the polyvalent carboxylic acids used for the polyester resin include: terephthalic acid, isophthalic acid, orthophthalic acid, 1,
5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 9,10-anthracene dicarboxylic acid,
9,10-anthracene dipropionic acid, diphenic acid,
Sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, sulfoterephthalic acid, and / or their metal salts, ammonium salts, etc. Aromatic carboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid,
Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, aliphatic unsaturated polycarboxylic acids such as fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid, and aromatic unsaturated polycarboxylic acids such as phenylenediacrylic acid Carboxylic acids-Alicyclic dicarboxylic acids such as hexahydrophthalic acid and tetrahydrophthalic acid-Trivalent or higher polycarboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid

In the present invention, a part of the polycarboxylic acids may be used together with the monocarboxylic acids. Aromatic monocarboxylic acids are preferred as the monocarboxylic acids. Examples of the aromatic monocarboxylic acid include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid,
And lower alkyl esters thereof, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid, tert-butylbutylbenzoic acid, naphthalenecarboxylic acid, anthracenecarboxylic acid, -Chart-butylnaphthalenecarboxylic acid can be used, and it is more preferable to use tert-butyl-benzoic acid. The amount of the aromatic monocarboxylic acid used is 2 to 25 mol% with respect to the acid component, and further 5 to 20 mol.
It is more preferred to use l%, or even 8 to 16 mol%.

In the present invention, 5 of such polyvalent carboxylic acid components are used.
It is essential to use more than mol% of unsaturated aliphatic polycarboxylic acid. As the unsaturated polycarboxylic acid in the present invention, fumaric acid and maleic acid are preferably used, and fumaric acid is more preferably used. The use of unsaturated polycarboxylic acid is required to be 5 mol% or more with respect to the acid component, and 20 to 50 mol%
Is preferable, and 30 to 50 mol% is more preferable.

Examples of the polyvalent alcohols used for the polyester resin include aliphatic polyvalent alcohols, alicyclic polyvalent alcohols, aromatic polyvalent alcohols and the like. As the aliphatic polyhydric alcohols, ethylene glycol
, Propylene glycol, 1,3-propanedioe
2,3-butanediol, 1,4-butanediol
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol
, Dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, polyethylene glycol
Examples include aliphatic diols such as propylene, polypropylene glycol and polytetramethylene glycol, triols such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol and tetraols. it can.

· 1,4 as alicyclic polyvalent alcohols
-Cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A, ethylene oxide adduct and propylene oxide adduct of hydrogenated bisphenol A, tricyclodecanediol , Tricyclodecane dimethanol, and the like. .As the aromatic polyhydric alcohols, ethylene oxide addition of para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, and 1,4-phenylene glycol Examples thereof include bisphenol A, bisphenol A, ethylene oxide adduct of bisphenol A, and propylene oxide adduct. Further, as the polyester polyol, lactone type polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone can be exemplified. Further, like the carboxylic acids, monoalcohols such as aliphatic alcohols, aromatic alcohols and alicyclic alcohols can be used.

The glass transition point of the polyester resin in the present invention is preferably 40 ° C. or higher, 45 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 70 ° C. or higher. If the glass transition point is lower than this, blocking tends to occur during handling or storage, and it may be difficult to handle the resulting powder. The number average molecular weight of the polyester resin of the present invention is preferably in the range of 1,000 to 20,000. Further, the range of 2000 or more and 5000 or less is preferable, and the range of 3000 or more and 4000 or less is more preferable.

In the present invention, the ionic group is 20 to 20.
00eq. It is essential to contain the polyester resin in the range of / ton. As the ionic group, a sulfonic acid group, a carboxyl group, a sulfuric acid group, a phosphoric acid group, a phosphonic acid group, a phosphinic acid group or an ammonium salt thereof,
It is an anionic group such as a metal salt or a cationic group such as a primary to tertiary amine group, and preferably an alkali metal sulfonate group or an ammonium carboxylate group can be used. It is preferable that these ionic groups are contained in a form copolymerized with polyester or introduced into the polymer terminal.

Examples of the polyvalent carboxylic acid containing a metal sulfonate which can be copolymerized with polyester include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid and 4
Examples thereof include sulfonaphthalene-2,7 dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, and / or salts thereof. Further, by using a metal salt of sulfobenzoic acid together, a metal sulfonate base can be introduced at the polymer terminal. As salts, ammonium-based ions, Li, Na, K, Mg, Ca, Cu, Fe,
Ni. Salts such as Co and Al are mentioned, and particularly preferable are K salt or Na salt. The carboxyl group can be added to the polymer terminal by introducing a polyvalent carboxylic acid such as trimellitic acid into the system at the final stage of polymerization of polyester. Further, by neutralizing this with ammonia, sodium hydroxide or the like, the carboxylate group can be exchanged. The content of these ionic groups is 20 to 2000 eq. Based on the polyester resin. / Ton is indispensable, and preferably 20 to 500 eq. / To
n, more preferably 50 to 200 eq. / Ton.

Examples of vinyl monomers used for crosslinking the polyester resin in the present invention include alkyl (meth) acrylate having an alkyl group having 1 to 10 carbon atoms, methoxyethyl (meth) acrylate, (meth). ) (Meth) acrylic acid esters such as hydroxyethyl acrylate, phenyl (meth) acrylate, cyclohexyl (meth) acrylate, glycidyl (meth) acrylate, methyl vinyl ketone, phenyl vinyl ketone, methyl isopropenyl ketone Unsaturated ketones such as
Vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate and vinyl butanoate, methyl vinyl ether,
Vinyl ethers such as ethyl vinyl ether, propyl vinyl ether, vinyl halides and vinylidene halides, acrylamide and its alkyl-substituted products, styrene, divinylbenzene, styrene alkyl-substituted products, styrene halogen-substituted products, Allyl alcohol and its ester or ether, acrolein,
Vinyl aldehydes such as methacrolein, acrylonitrile, methacrylonitrile, vinyl monomers such as vinylidene cyanide, and acrylic acid, methacrylic acid,
Unsaturated carboxylic acids such as fumaric acid, maleic acid and itaconic acid and salts thereof, unsaturated hydrocarbon sulfonic acids such as vinyl sulfonic acid, acryl sulfonic acid and parastyrene sulfonic acid and salts thereof, phosphorus having a double bond Acid esters and salts thereof, pyridine, vinylpyrrolidone, vinylimidazole, vinylcarbazol, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (methacrylate, etc. can be used. Ring-opening polymerization type monomers such as siloxanes, lactones, lactams and epoxy compounds may be used in combination.

The reaction initiator is not particularly limited, and a known initiator may be used. For example, benzoylperoxide, parachlorobenzoylperoxide, 2,4-dichlorobenzoylperoxide, caprylylperoxide, laurylperoxide, acetylperoxide, methylethylketoneperoxide, cyclohexanoneperoxide, bis (1-hydroxycyclohexyl). Peroxide), hydroxyheptylperoxide, t-butylhydroperoxide, p-menthanperoxide, cumenehydro, 2,5-dimethylhexyl-2,5-dihydroper
Oxide, di-t-butylperoxide, dicumylperoxide, 2,5-dimethyl-2,5-di (per)
Oxybenzoate), t-butylperbenzoate,
t-butyl peracetate, t-butyl per octet
, T-butyl peroxy oxyisobutyrate, di-t-butyl di-per phthalate, organic peroxide initiators such as peroxysuccinic acid, azoisobutyl nitrile, disoxybenzoyl, phenylacetaldehyde, phenylpyroglucose, An initiator such as a pinaconic acid derivative can be used. As the reaction accelerator, cobalt-based, vanadium-based, manganese-based, tertiary amine-based, quaternary ammonium salt-based,
A reaction promoter such as a mercaptan type can be used.

A specific method for obtaining the hollow crosslinked polyester resin particles of the present invention will be described below. As a method for obtaining the hollow crosslinked polyester resin particles of the present invention, a method of forming hollow polyester particles, then swelling the particles with a vinyl monomer and post-crosslinking the particles. A method of crosslinking simultaneously with the formation of hollow polyester particles. There are two types.

As a method of obtaining hollow polyester resin particles, 1) a method of hollowing the polyester particles at the same time as the formation of the polyester particles. a) For example, by dissolving the ionic group-containing polyester resin in a water-soluble organic compound and then adding water, W /
A method for forming hollow particles by forming an O / W emulsion. 2) A method of hollowing the solid polyester particles by post-treatment. a) a method of heat-treating solid particles of an ionic group-containing polyester resin to a glass transition temperature or higher in an aqueous medium, b) after adding a water-soluble organic compound to an aqueous dispersion of ionic group-containing polyester resin particles A method of hollowing when removing the water-soluble organic compound by azeotropic distillation, c) A solvent is added to an aqueous dispersion of ionic group-containing polyester resin particles, and the particles are swollen, followed by a method such as spray drying. Examples thereof include a method of hollowing when drying, and the like. As the solid polyester particles used in each of the latter 2) -a) ~ b), resin particles obtained by pulverizing and classifying an ionic group-containing polyester resin may be used, but preferably the water-based molding described below. It is preferable to use polyester resin particles obtained by a granulation method. Hollow particles made of crosslinked polyester can be obtained by swelling the hollow particles thus obtained with a vinyl monomer and post-crosslinking them.

As a method for crosslinking the hollow polyester particles at the same time, 1) solid particles of an ionic group-containing polyester resin are swollen with a vinyl monomer in an aqueous medium, and at the same time, heat treatment is performed at a temperature not lower than the glass transition temperature. As a result, a method of simultaneously performing hollowing and crosslinking can be exemplified. As the solid polyester particles used at this time, similar to the above, resin particles obtained by pulverizing and classifying an ionic group-containing polyester resin may be used, but if possible, a polyester resin obtained by an aqueous granulation method It is preferable to use particles.

The method for forming polyester particles by the water-based granulation method will be described below. The ionic group-containing polyester resin in the present invention has water dispersibility. The aqueous fine dispersion of the ionic group-containing polyester resin of the present invention can be produced by any known method. That is,
An ionic group-containing polyester resin and a water-soluble organic compound are premixed at 50 to 200 ° C., and water is added thereto, or a mixture of an ionic group-containing polyester resin and a water-soluble organic compound is added to water, 40-120 ° C
It is manufactured by stirring at. Alternatively, it is also produced by a method in which an ionic group-containing polyester resin is added to a mixed solution of water and a water-soluble organic compound and dispersed by stirring at 40 to 100 ° C. As the water-soluble organic compound, ethanol, butanol, isopropanol, ethyl cellosolve, butyl cellosolve, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, etc. can be used. It is not preferable to use a surfactant together, but the use is not particularly limited. The average particle size of the water-based fine dispersion thus obtained is approximately 0.01 to
It is about 1.0 μm. In the aqueous microdispersion of the ionic group-containing polyester resin, under conditions where the ionic group-containing polyester resin is plasticized, by means such as addition of an electrolyte or the like, the finely dispersed particles are guided to a slow aggregation region, and particle growth occurs. By doing so, polyester particles can be obtained.

As the electrolyte used in the present invention, sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium chloride, calcium chloride, cobalt chloride, strontium chloride. , General inorganic or organic water-soluble salts such as cesium chloride, barium chloride, nickel chloride, magnesium chloride, rubidium chloride, sodium chloride, potassium chloride, sodium acetate, ammonium acetate, potassium acetate, sodium benzoate, etc. Can be used. The concentration of these electrolytes is 0.01 when a monovalent electrolyte is used.
The range of -2.0 mol / l, more preferably 0.1-1.0 mol / l, and even more preferably 0.2-0.8 mol / l. Further, when a polyvalent electrolyte is used, its addition amount may be smaller. In the present invention, the objective can be sufficiently achieved by preliminarily charging the electrolyte into the system, or by post-adding it, but preferably by "electrolyzing after adding the electrolyte precursor" Further, good quality polyester resin particles can be obtained.

As the electrolyte precursor, for example, a salt which is hardly soluble at low temperature and easily soluble at high temperature, pH, temperature, pressure, light irradiation,
Examples of the compound include a compound that decomposes into an electrolyte by the like. In the present invention, ester compounds of amino alcohols and carboxylic acids can be used as preferred electrolyte precursors. Since such an ester compound has an amino group, it is water-soluble, and its aqueous solution is alkaline. When the temperature of the alkaline aqueous solution is raised, the ester bond is hydrolyzed to form a salt of amino alcohol and carboxylic acid. The amino group actually functions as a primary ammonium group or a tertiary ammonium group. Preferred amino alcohols in the present invention include amino ethanol, 1,3-amino propanol, 1,4-amino butanol, dimethyl amino ethanol, 1,3-dimethyl amino propanol and diethyl amino ethanol. , Diethylaminopropanol and the like can be used. Examples of the carboxylic acids include benzoic acid and its derivative, naphthalenecarboxylic acid, and its derivative, salicylic acid, thiosalicylic acid,
Phenylacetic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, dodecanoic acid, lauric acid, stearyl acid, acrylic acid, methacrylic acid and the like can be used. Further, in the present invention, an ester in any combination of these amino alcohols and carboxylic acids can be preferably used as the electrolyte precursor.

The polyester particles thus obtained are substantially spherical, have a sharp particle size distribution, and are capable of high-temperature dispersion dyeing at high density. The polyester particles thus obtained have a volume average particle diameter D of 1 to 100.
It can be freely controlled in the range of μm (depending on the electrolyte concentration, temperature, and time), and the particle size distribution is 0.5D to 2.
Particles in the range of 0D occupy 80% by weight or more of the whole, a coefficient of variation of 30% or less is sharp, and a substantially spherical polyester having an average sphericity (minor axis / major axis) of 0.8 or more. Become particles. The specificity of the particles of the present invention with respect to the particles of vinyl polymer obtained by suspension polymerization or the like is exhibited not only in the variety of physical properties of the polyester resin but also in the shape and particle size distribution of such polyester particles. In general, suspension-polymerized particles have a broad particle size distribution and only a coefficient of variation of about 30% or more can be obtained. In the present invention, particles having a particle diameter in the range of 0.5D to 2.0D are adjusted to 80% by weight or more, preferably 85% by weight or more, more preferably 90% by weight or more, and further preferably 95 by adjusting the particle formation conditions. It is possible to obtain a product having a weight% or more.
The coefficient of variation is 30% or less, preferably 20% or less, more preferably 15% or less, and further preferably 10%.
It can be less than or equal to%. The average sphericity (minor axis / major axis) can be 0.8 or more, preferably 0.85 or more, more preferably 0.9 or more, still more preferably 0.95 or more. Here, the coefficient of variation means a value obtained by dividing the standard deviation by the average value.

In the present invention, the polyester particles thus obtained are preferably used as seed particles for hollowing and cross-linking. The polyester particles obtained by this water-based granulation method have stable dispersion in an aqueous medium. Very high, swelling operation with a vinyl monomer, or does not aggregate even if subjected to heat treatment at a glass transition temperature or higher, the crosslinked hollow resin particles thus obtained maintain the particle size distribution of the polyester seed particles, Diameter 0.5D ~
The particles in the range of 2.0D are 80% by weight or more, preferably 85% by weight or more, more preferably 90% by weight or more, further preferably 95% by weight or more, and the coefficient of variation is 30% or less, preferably It can be 20% or less, more preferably 15% or less, even more preferably 10% or less, and even more preferably 7% or less. In the present invention: It is most preferable to use a method of heat treatment at a temperature not lower than the glass transition temperature. According to this method, the hollowness can be arbitrarily controlled by the temperature of heat treatment and the concentration of electrolyte in the system. The treatment temperature is preferably a temperature between the glass transition temperature of the polyester resin and 200 ° C, more preferably 140 ° C or lower, further preferably 100 ° C or lower, and further preferably 90 ° C or lower. The electrolyte concentration is preferably 0.2 mol / l or less, 0.1 mol / l
The following is more preferable, and 0.05 mol / l or less is further preferable.

Different kinds of aqueous dispersions can be incorporated into the polyester resin particles of the present invention by heteroaggregation during the particle growth process. It is also possible to use a polyester fine dispersion colored with a dye or the like. In this way it is possible to color and functionalize the particles. The heterogeneous water dispersion is, for example, a dispersion of pigment, latex, carbon black or the like. The obtained particles are washed and dehydrated, and then taken out as a dry powder by means such as freeze drying, spray drying, fluidized drying, and vacuum drying. Of course, depending on the application, it is used in a state of being dispersed in an aqueous medium. It is also possible to replace and use the contents of the internal holes.

The resin particles of the present invention described above are crosslinked resin particles having particularly excellent heat resistance and solvent resistance because the unsaturated double bond contained in the polyester is crosslinked with the polymerization of the vinyl monomer. Since the polyester resin particles used as the seed particles of the present invention are very stably dispersed in an aqueous medium, so-called suspension stabilizers such as poval, hydroxyethyl cellulose or inorganic particles such as silica are required. Not. Although such suspension stabilizers are desired to be removed after the particles are obtained, they are generally difficult to remove, and the applications of the obtained particles are significantly limited. The crosslinked resin particles can be easily obtained by suspension polymerization of a vinyl resin containing a monomer having two or more vinyl bonds in the molecule, but the particle size range is broad. However, it is difficult to obtain crosslinked particles having a fine and uniform particle size. However, the crosslinked resin particles of the present invention are not only excellent in heat resistance and solvent resistance, but also freely controllable in a wide range of particle diameters, exhibiting a sharp particle diameter distribution, and having a substantially spherical shape. It has excellent characteristics such as certain characteristics.

Furthermore, since the particles of the present invention have appropriate pores inside, they have a high light scattering effect, and when used as an additive for paints, a high degree of whiteness can be produced. In addition, high heat insulation can be expected due to the heat retaining effect of the internal pores. Furthermore, when the internal pores are filled with gas, the apparent specific gravity is small, which is advantageous for weight reduction. Further, for the same reason, the apparent relative dielectric constant is small, so that it is also useful as a low dielectric material. These effects are expected even in the conventionally known vinyl polymer hollow resin particles, but in the present invention, since a polyester resin is further used as the main constituent component, it becomes a highly versatile polyester film. It is excellent in matching with a polyester binder having high adhesiveness, and when blended in such a binder, excellent effects can be obtained.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

【Example】

[Polymerization of Polyester Resins (A1) to (A3) and (A6)] 80 parts by weight of dimethyl terephthalate and 80 parts by weight of dimethyl ester of isophthalic acid were placed in an autoclave equipped with a thermometer and a stirrer. -Sodium sulfoisophthalic acid dimethyl ester 6 parts by weight Ethylene glycol 68 parts by weight, neopentyl glycol 114 parts by weight, and tetrabutoxy titanate 0.1 parts by weight were charged and heated at 120 to 220 ° C for 120 minutes. Transesterification was carried out. Then, set the temperature of the reaction system to 180 ° C.
20 parts by weight of fumaric acid and 0.1 parts by weight of hydroquinone were added, and the reaction was continued at 200 ° C. for 60 minutes, after which the temperature of the reaction system was raised to 220 to 240 ° C. and the system pressure was 1 to 1
As a result of continuing the reaction at 0 mmHg for 60 minutes, a copolyester resin (A1) was obtained. The composition, glass transition temperature, acid value, molecular weight and sodium sulfonate group equivalent of the obtained copolyester resin (A1) are shown in Table 1. Shown in. NMR analysis for polyester composition, DS for glass transition temperature
C, acid value was titrated, molecular weight was determined by GPC, and sodium sulfonate group equivalent was determined by S. Thereafter, the raw materials were changed and the same polymerization was carried out. Polyester resin (A
2) to (A3) and (A6) were obtained.

[0030]

[Table 1] [Polymerization of polyester resin (A4)] In an autoclave equipped with a thermometer and a stirrer, 129 parts by weight of dimethyl terephthalate, 3 parts by weight of dimethyl ester of 5-sodium sulfoisophthalic acid, ethylene glycol 50 280 parts by weight of propylene oxide adduct of bisphenol A and 0.1 part by weight of tetrabutoxy titanate were charged and heated at 150 to 220 ° C. for 180 minutes for transesterification reaction. Then, the temperature of the reaction system is lowered to 180 ° C., 29 parts by weight of maleic anhydride and 0.1 part by weight of hydroquinone are added, the reaction is continued at 200 ° C. for 60 minutes, and then the temperature of the reaction system is raised to 220 to 240 ° C. Then, the pressure of the system was gradually reduced to 10 mmHg after 30 minutes, and the reaction was continued for 60 minutes. After that, the atmosphere in the autoclave was replaced with nitrogen gas and the pressure was adjusted to atmospheric pressure. The temperature was kept at 200 ° C, trimellitic anhydride was added, and the reaction was carried out for 60 minutes. A copolyester resin (A4) shown in was obtained.

[Polymerization of polyester resin (A5)] Bisphenol was placed in an autoclave equipped with a thermometer and a stirrer.
700 parts by weight of the propylene oxide adduct of A, 196 parts by weight of maleic anhydride, and 1 part by weight of hydroquinone were charged, and nitrogen gas was introduced into the reaction system to maintain an inert atmosphere, and 0.05 part by weight of dibutyltin oxide was added. Plus 20
React at 0 ° C. Polyester resin (A
5) was obtained. In addition, Table 1. Medium NDC is 1,5-naphthalenedicarboxylic acid TPA is terephthalic acid IPA is isophthalic acid SIP is 5-sodium sulfoisophthalic acid FA is fumaric acid MA is maleic acid TMA is trimellitic acid EG is ethylene glycol NPG is neopentyl glycol BPP is a propylene oxide adduct of bisphenol A (average molecular weight 350) Tg is a glass transition temperature.

[Production of Polyester Aqueous Micro Dispersion] 8 parts by weight of polyester resin (A1) 300 parts by weight, methyl ethyl ketone 150 parts by weight, and tetrahydrofuran 140 parts by weight.
After dissolving at 0 ° C., 680 parts of water at 80 ° C. was added to obtain a water-based fine dispersion of a copolymerized polyester resin having a particle diameter of about 0.1 μm, which was then placed in a distillation flask and the distillation temperature was 100%.
Distilled until the temperature reached ℃, and after cooling, water was added to remove the solvent, and the polyester water-based finely dispersed particles with a solid content concentration of 30% (B
1) was obtained. A polyester resin (A
(B2) and (B3) were obtained from 2) and (A3), respectively.

100 parts of butanol was added to 300 parts of polyester (A4) and dissolved at 90 ° C., and then cooled to 80 ° C. Further, 1N aqueous ammonia solution was added so that the acid value of the copolyester was equal to the acid value, and the mixture was stirred at 80 ° C. for 30 minutes and then 500 parts of water at 80 ° C. was added to obtain an aqueous microdispersion of the copolyester. It was The resulting water microdispersion was placed in a distillation flask, distilled until the distillation temperature reached 100 ° C., then cooled, and finally desolvated. A water microdispersion of a copolyester having a solid content concentration of 30%. (B
4) was obtained. A polyester resin (A
A fine dispersion (B5) was obtained from 5). The same operation was performed using the resin polyester (A6), but a fine dispersion could not be obtained.

[Production of Polyester Particles: Wet Granulation Method]
A 4-liter 1-liter separable flask equipped with a thermometer, a condenser, and a stirring blade was charged with 300 parts by weight of the polyester water-based fine dispersion (B1), and the temperature was raised to 80 ° C. Then, 20% by weight of dimethylaminoethyl methacrylate
40 parts by weight of aqueous solution was added over 60 minutes (0.2 m
ol / l) and stirring was continued for another 300 minutes at 80 ° C. The conductivity in the system increased from about 1 mS to 25 mS, and the pH decreased from 10.8 to 6.7. From this, it was confirmed that the added dimethylaminoethyl methacrylate was almost completely hydrolyzed afterward to form a salt of dimethylaminoethanol and methacrylic acid. The submicron-order particle size copolymer present in the polyester water-based microdispersion grows into coalesced particles over time,
Table 2. Polyester spherical particles (C1) shown in Table 1 were obtained. Table 2. Medium, average particle size, particle size distribution, coefficient of variation
It was measured using a digital counter-TA2. The sphericity was measured by processing a scanning electron micrograph of the particles with an image processing device Image Analyzer V1 [manufactured by Toyobo Co., Ltd.]. In the table, DAM represents dimethylaminoethyl methacrylate. Experiments were performed in the same manner, except that the raw materials and conditions were changed, and Table 2. Polyester particles (C
2) to (C6) were obtained.

[0035]

[Table 2] [Production of Polyester Particles: Crushing Method] The polyester resin (A3) is roughly crushed by a chopper mill, and then finely crushed by a supersonic jet mill PJM200 type, and crushed particles (C
7) was obtained. Similarly, crushed particles (C8) were obtained from the polyester resin (A6).

[Preparation of hollow particles] Polyester particles (C
1) was dehydrated and washed, redispersed in water, and then diluted with deionized water to obtain an aqueous dispersion of polyester particles having a solid content concentration adjusted to 5%. 1000 parts by weight of the polyester aqueous dispersion was placed in a separable flask and the temperature of the system was raised to 90 ° C. with gentle stirring, and after 30 minutes, 2000 parts by weight of deionized water was poured to cool the system. The obtained particles were dehydrated and washed with a suction funnel and redispersed in water to obtain hollow polyester particles (D1). Similarly, the polyester particles (C
Hollow particles (D2) to (D7) were obtained from 2) to (C7). When polyester particles (C8) were used, the particles agglomerated during the temperature rise, and hollow particles could not be obtained.

[Crosslinking] An aqueous dispersion of hollow polyester particles (D1) was diluted with deionized water to obtain a polyester particle aqueous dispersion having a solid content concentration adjusted to 5%. 1000 parts by weight of the polyester aqueous dispersion was placed in a separable flask, 50 parts by weight of distilled styrene in which 1% by weight of benzoyl peroxide was dissolved was added dropwise with gentle stirring, and stirring was continued for 30 minutes. The reaction was continued for 300 minutes. After cooling the system to room temperature, the obtained particles were dehydrated and washed with a suction funnel and vacuum dried to obtain hollow crosslinked polyester dry particles (E1). The average particle size, particle size distribution, coefficient of variation, sphericity, apparent specific gravity, and porosity of the obtained particles are shown in Table 3. Shown in. The porosity was obtained from the difference in particle density. The obtained particles were immersed in toluene, and solvent resistance was evaluated by whether or not the particle shape could be retained. Further, the particles were placed on a hot plate at 100 ° C., and heat resistance was evaluated by whether or not the particle shape could be maintained. As a result, all particles have good heat resistance
It had solvent resistance.

[0038]

[Table 3] [Hollowing simultaneous crosslinking / control of porosity] Aqueous dispersion 1000 of polyester particles (C3) having a solid content concentration adjusted to 2%
Parts by weight, 0.58 g (0.
(Corresponding to 01 mol / l) and 20 parts by weight of distilled styrene in which 1% by weight of benzoyl peroxide was dissolved were placed in a stainless steel pot of a dye tester, Mini Color [made by Texum Giken], treated at 90 ° C. for 120 minutes, and cooled to obtain water. Hollow polyester particles are dehydrated and washed with a suction funnel and dried in vacuum.
The hollow particles (E9) shown in (1) were obtained. In the same manner, experiments were conducted in the same manner by changing the temperature and the electrolyte concentration, and hollow polyester particles (E1
0) to (E16) were obtained. That is, in the present invention, it was shown that the porosity can be controlled by the concentration of the electrolytic chamber of the treatment system and the treatment temperature. The heat resistance and solvent resistance of the obtained particles were evaluated, and all the particles had good heat resistance and solvent resistance.

[0039]

[Table 4] [Low specific gravity, low dielectric constant molded product] Polyester resin (A1)
The water dispersion (B1) obtained from the above was used as an aqueous binder. 20 parts by weight of styrene in which 1 part by weight of benzoylperoxide was dissolved was added to 100 parts by weight of the binder, and the mixture was stirred for 30 minutes at room temperature. Further, 500 parts by weight of dehydrated cake of the hollow crosslinked particles E1 was added thereto, mixed, poured into a silicone rubber mold, heated at 70 ° C. for 120 minutes, cooled, and vacuum dried to obtain a molded body. The apparent specific gravity of the obtained molded product was 0.72. When the relative permittivity of the molded body obtained by the Q-meter method was measured, the relative permittivity was 1.94. [White polyester coat film] 50 parts by weight of a dehydrated cake was added to 200 parts by weight of the above water-based binder and stirred. The obtained dispersion was applied on a polyester film with a bar coater and dried and cured. The obtained film was excellent in whiteness, and the adhesiveness of the coating film was 100/100 as a result of the cross-cut cross-cut tape peel test.

[0040]

As described above, the polyester particles in the present invention are particles of a polyester resin which is a condensation polymer, have an arbitrary particle diameter and an arbitrary porosity, and have a low specific gravity. It has a low dielectric constant, is excellent in heat resistance and solvent resistance, and is excellent in matching with polyester binders and films.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanori Kobayashi 2-1-1 Katata, Otsu City, Shiga Toyobo Co., Ltd. (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd.

Claims (1)

[Claims] 1. Obtained by condensation of a polyvalent carboxylic acid component containing 5 mol% or more of an unsaturated polyvalent carboxylic acid and a polyvalent alcohol component, and 20 to 2000 eq. / Ton polyester resin containing ionic groups in the range of 1 to 95
The main component is a cross-linked resin obtained by polymerizing 5% to 99% by weight of a vinyl-based monomer, and then the volume average particle diameter D is in the range of 0.5 to 100 μm. A crosslinked polyester-based particle having a single or a plurality of independent pores filled with a gas or a liquid and having a porosity in the range of 1 to 99 vol%.