JPH0770331A - Polyester particle - Google Patents

Abstract

PURPOSE:To obtain polyester particles having a low specific gravity, a low dielectric constant, closed cells in the inside, and specified particle size, void content, etc., by converting a polyester resin having ionic groups into hollow particles by a specific method. CONSTITUTION:The title particles mainly comprise a polyester resin contg. 20-200eq./ton ionic group and have a vol.-average particle size of 0.5-100mum and a void content of 1-99vol.%, each particle contg. a closed cell or cells filled with a gas or liq. The particles are produced, e.g. by dissolving the resin in a water-sol. org. compd. (e.g. ethanol) and adding water to the resulting soln. to form a W/O/W emulsion, and are suitable as a delusterant, an antiblocking agent, a carrier for chromatography, etc.

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, 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 voids inside are limited to vinyl-based polymers, are excellent in matching with polyester-based binders, and have an arbitrary average particle diameter and sharpness. Resin particles having a particle size distribution and having inner pores have not been known.

[0005]

That is, the present invention provides 20
~ 2000 eq. / Ton is a main component of a polyester resin containing an ionic group, the volume average particle diameter D is in the range of 0.5 ~ 100μm, the particles are filled with gas or liquid single or plural The polyester particles have independent pores and a porosity in the range of 1 to 99 vol%.

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 have a polyester resin as a main component. The polyester resin must be used in an amount of 50 wt% or more of the total resin component, preferably 80 wt% or more, more preferably 90 wt% or more, further 95 wt% or more, still more 9%.
It is preferable that the content is 8 wt% or more. The polyester resin in the present invention means a polyvalent carboxylic acid and a polyvalent alcohol.
Consists of 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 polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid can be exemplified.

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 these lower alkyl esters, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid, t-butylbutylbenzoic acid, naphthalenecarboxylic acid, anthracenecarboxylic acid, Tertiary butyl naphthalene carboxylic acid or the like can be used, and it is particularly preferred to use tertiary 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 mol% or more of such a polycarboxylic acid component can be used as an 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. Use of unsaturated polycarboxylic acid is 5 mol% to acid component
The above is essential, 20-50 mol% is preferable, and 30-
50 mol% is more preferable.

Examples of the polyvalent alcohols used in 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.

・ Alicyclic polyvalent alcohols are 1,4
-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, still more 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 copolymerizable with polyester include sulfoterephthalic acid, 5-sulfoisophthalic acid,
4-sulfophthalic acid, 4-sulfonaphthalene-2,7 dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid, and / or salts thereof can be exemplified.
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. / Ton, more preferably 50 to 200 eq. / Ton. The above are the essential requirements that characterize the hollow polyester resin particles of the present invention.

A specific method for obtaining the polyester resin particles of the present invention will be described below. As a method of obtaining the hollow polyester resin particles of the present invention, a method of hollowing the polyester particles at the same time as the formation of the polyester particles. A method of hollowing the solid polyester particles by post-treatment. There are two types.

Examples of the former method include 1) a method of dissolving the ionic group-containing polyester resin in a water-soluble organic compound and then adding water to form a W / O / W type emulsion to obtain hollow particles. . The latter includes 2) 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, 3) a water-soluble organic compound in an aqueous dispersion of ionic group-containing polyester resin particles A method of making hollow when removing the water-soluble organic compound by azeotropy after adding, 4) adding a solvent to the aqueous dispersion of the ionic group-containing polyester resin particles, swelling the particles and then spray drying etc. Examples of the method include hollowing when dried by the method described above. As the faithful polyester particles used in the latter 2) to 4), resin particles obtained by pulverizing and classifying an ionic group-containing polyester resin may be used, but preferably polyester obtained by the method described below It is preferable to use resin particles.

The ionic group-containing polyester resin of 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, the ionic group-containing polyester resin and the water-soluble organic compound are mixed in an amount of 50 to 200.
It is manufactured by mixing in advance at 0 ° C and adding water thereto, or adding a mixture of an ionic group-containing polyester resin and a water-soluble organic compound to water and stirring at 40 to 120 ° C. 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. Ethanol as the water-soluble organic compound,
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 about 0.01 to 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 exerted 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. To be done. Generally, suspension polymerized particles have a broad particle size distribution and a coefficient of variation of 3
Only 0% 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 can be 30% or less, preferably 20% or less, more preferably 15% or less, and further preferably 10% or less. Average sphericity (minor axis / major axis)
It 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.

As described above, the polyester resin particles thus obtained are dispersed in an aqueous medium as follows: A method of heat treatment at a temperature not lower than the glass transition temperature; An azeotropic process after adding a water-soluble organic compound. A method of hollowing when removing the water-soluble organic compound by, a method of hollowing when drying by a method such as spray drying after adding a solvent to swell the particles, and the like. Thus, predetermined hollow particles are obtained. 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.
A temperature of 40 ° C or lower is more preferable, 100 ° C or lower is still more preferable, and 90 ° C or lower is further preferable. The electrolyte concentration is preferably 0.2 mol / l or less, more preferably 0.1 mol / l or less, and further preferably 0.05 mol / l or less.

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.

The hollow resin particles containing the polyester resin as the main component thus obtained have appropriate voids inside, and therefore have a high light scattering effect, and when used as an additive for paints, produce a high degree of whiteness. be able to. 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. When the polyester resin has an unsaturated double bond, heat resistance and solvent resistance can be improved by means such as crosslinking. 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. Highly adhesive polyester binder
It is excellent in matching with, and an excellent effect can be obtained when compounded with such a binder.

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

Examples [Polymerization of Polyester Resins (A1) to (A3) and (A6)] 80 parts by weight of terephthalic acid dimethyl ester and 80 parts by weight of isophthalic acid dimethyl ester were placed in an autoclave equipped with a thermometer and a stirrer. Parts by weight, 6 parts by weight of 5-sodium sulfoisophthalic acid dimethyl ester, 68 parts by weight of ethylene glycol, 114 parts by weight of neopentyl glycol, and 0.1 part by weight of tetrabutoxy titanate were charged at 120 to 220 ° C. And heated for 120 minutes to carry out the transesterification reaction. 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) were obtained.

[0026]

[Table 1] [Polymerization of polyester resin (A4)] In an autoclave equipped with a thermometer and a stirrer, 128 parts by weight of dimethyl terephthalate, 45 parts by weight of ethylene glycol, and propylene oxide addition of bisphenol A. 270 parts by weight of the product, 0.1 parts by weight of tetrabutoxy titanate were charged and heated at 150 to 220 ° C. for 180 minutes to carry out a 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., 8 parts by weight of trimellitic anhydride was added, and the reaction was carried out for 60 minutes. To obtain a copolyester resin (A5). [Polymerization of polyester resin (A5)] 700 parts by weight of a propylene oxide adduct of bisphenol A and 1 part of maleic anhydride were placed in an autoclave equipped with a thermometer and a stirrer.
96 parts by weight and 1 part by weight of hydroquinone were charged, nitrogen gas was introduced into the reaction system to maintain an inert atmosphere, 0.05 part by weight of dibutyltin oxide was added, and the reaction was carried out at 200 ° C. To obtain a polyester resin (A5).

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] 300 parts by weight of polyester resin (A1), 150 parts by weight of methyl ethyl ketone, and 140 parts by weight of tetrahydrofuran are added.
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. Butanol 10 parts to 300 parts of polyester (A4)
After 0 part was added and dissolved at 90 ° C, the mixture was cooled to 80 ° C.
In addition, make the acid value of the copolyester equal to 1
An aqueous ammonia solution of N was added, 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 a copolyester. 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%. (B4) was obtained. Thereafter, a fine dispersion (B5) was obtained from the polyester resin (A5) by the same method. 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.

[0030]

[Table 2] [Production of Polyester Particles: Crushing Method] The polyester resin (A3) was roughly crushed with a chopper mill and then finely crushed with a supersonic jet mill PJM200 type to obtain a crushed crusher (C7). Similarly, crushed particles (C8) were obtained from the polyester resin (A6).

[Creation 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 vacuum dried to obtain hollow polyester particles (D1). 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. Similarly, from the polyester particles (C2) to (C7), hollow particles (D
2) to (D7) were obtained. When polyester particles (C8) were used, the particles agglomerated during the temperature rise, and hollow particles could not be obtained.

[0032]

[Table 3] [Control of porosity] 1000 parts by weight of an aqueous dispersion of polyester particles (C3) having a solid content concentration adjusted to 2%, and 0.58 g of sodium chloride as an electrolyte (equivalent to 0.01 mol / l)
Was placed in a stainless steel pot of a dye tester Mini Color [made by Texam Giken], treated at 90 ° C. for 30 minutes and cooled with water, and the obtained particles were dehydrated and washed with a suction funnel and vacuum dried to give hollow polyester particles. To obtain hollow particles (D9). In the same manner, experiments were carried out by changing the temperature and the electrolyte concentration to obtain hollow polyester particles (D10) to (D16). 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.

[0033]

[Table 4] [Low specific gravity, low dielectric constant molded product] 1000 parts by weight of an aqueous dispersion of polyester particles (C3) having a solid content concentration adjusted to 2%, and sodium chloride 1.16 g (0.02) as an electrolyte.
(corresponding to mol / l) was placed in a stainless steel pot of a dye tester Mini Color [made by Texum Giken], treated at 90 ° C. for 30 minutes and cooled with water, and the obtained particles were dehydrated and washed with a suction funnel to fill the pores with water. The obtained polyester hollow particles were obtained. The water content of the dehydrated cake of the obtained polyester hollow particles was 7
It was 6%.

The aqueous dispersion (B1) obtained from the polyester resin (A1) 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. In addition to this, the dehydrated cake 5 previously obtained was added.
After adding and mixing 100 parts by weight, the mixture was 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 is 0.
It was 68. When the relative permittivity of the molded body obtained by the Q-meter method was measured, the relative permittivity was 1.87. [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.

[0035]

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 and is excellent in matching with polyester binders and films.

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

Claims (1)

[Claims] 1. 20 to 2000 eq. The main component is a polyester resin containing an ionic group in the range of / ton,
The volume average particle diameter D is in the range of 0.5 to 100 μm,
Polyester particles having single or plural independent pores filled with gas or liquid inside the particles and having a porosity in the range of 1 to 99 vol%.