JPH0616820A - Sphetical polyester particle - Google Patents

Abstract

PURPOSE:To obtain polyester particles which change little in material properties upon moisture absorption and have high environmental stability by dispersing into an aqueous medium a polyester obtained by the condensation of an alcohol component with an acid component consisting mainly of an aromatic dicarboxylic acid and containing an aromatic monocarboxylic acid, and gently aggregating the particles. CONSTITUTION:An acid component comprising 60-98mol% aromatic dicarboxylic acid and 2-25mol% aromatic monocarboxylic acid is condensed with an alcohol component containing 60-100mol% aliphatic polyhydric alcohol and 0-40mol% alicyclic polyhydric alcohol to obtain a polyester resin. An ionic group is incorporated into the resin in an amount of 20-500eq/ton. The resulting resin is finely dispersed ink an aqueous medium. The stability of the finely dispersed particles is controlled to gently aggregate the particles to thereby obtain spherical polyester particles which have a volume-average particle diameter D of 1-100mum and an average degree of sphericity (minor axis/major axis) of 0.8 or higher and in which the particles having particle diameters of 0.5.D to 2.0.D account for 80wt.% or more of all the particles.

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, 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 particles of a polyester-based resin having a small change in physical properties due to environmental humidity and high environmental stability.

[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.

In order to solve the above problems, the present inventors industrially use a polyester resin having an arbitrary average particle size and a sharp particle size distribution and being a condensation polymer. Japanese Patent Laid-Open No. 3-212444 has been proposed as a means for enabling the production of resin particles.
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.

[0004]

However, in the subsequent research, since the ionic group contained in the polyester has hygroscopicity in the present invention, various physical properties of the particles are affected by the temperature and humidity of the environment. I found the problem that it was easy. The present inventors have earnestly conducted research to realize even more excellent polyester particles, and as a result, arrived at the next invention.

[0005]

Means for Solving the Problems That is, the present invention comprises: a) an aromatic dicarboxylic acid 60 to 98 mol% b) an acid component containing 2 to 25 mol% of an aromatic monocarboxylic acid; and c) an aliphatic polyvalent acid. Alcohol 60 to 100 mol% d) Obtained by condensation of an alcohol component containing 0 to 40 mol% of alicyclic polyvalent alcohol, and
20-500 eq. / Ton is the main component of the polyester resin containing an ionic group, the volume average particle diameter D
Is 1 to 100 μm, particles having a particle diameter of 0.5D to 2.0D account for 80% by weight or more of the whole, and are spherical spheres (minor axis / major axis) of 0.8 or more.

As the aromatic dicarboxylic acid in the present invention, for example, terephthalic acid, isophthalic acid, sulfoisophthalic acid and / or its ammonium salt or alkali metal salt, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6 -Naphthalenedicarboxylic acid, diphenic acid, 4-4 'diphenyldicarboxylic acid and the like can be used. In the present invention, it is essential to use the aromatic dicarboxylic acid in the range of 60 to 98 mol%, more preferably 70 to 95 mol%, and further preferably 80 to 95 mol% with respect to the acid component. In the present invention, the polycarboxylic acid is preferably 40 to 95 mol% of terephthalic acid, 5 to 60 mol% of isophthalic acid, and the sum of terephthalic acid and isophthalic acid is preferably 80 mol% or more. The content of terephthalic acid is 60 ~ 95mol%, and more preferably 70 ~ 90mol%
Is more preferable, and the total sum of terephthalic acid and isophthalic acid is more preferably 90 mol% or more.

In the present invention, trimellitic acid, trimesic acid, pyromellitic acid and the like can be used as the trivalent or higher polycarboxylic acid. Trivalent or higher polycarboxylic acid can be used in the range of 0 to 8 mol%. Again 1
It is more preferable to use about 6 to 6 mol%, and further about 3 to 5 mol%.

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 and phenylacetic acid. And lower alkyl esters thereof, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid,
Char-butyl benzoic acid, tert-butyl naphthalene carboxylic acid, etc. 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.
Is essential, 5 to 20 mol%, and 8 to 1
The use of 6 mol% is more preferable.

Other polycarboxylic acids include aromatic oxycarboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid. Aliphatic dicarboxylic acid, fumaric acid, maleic acid, itaconic acid,
Unsaturated aliphatic such as hexahydrophthalic acid and tetrahydrophthalic acid, and alicyclic dicarboxylic acid can be used.

As the aliphatic polyhydric alcohol in the present invention, ethylene glycol, propylene glycol,
1,3-propanediol, 2,3-butanediol,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, neopentyl glycol,
Alkylene glycol such as 2,2,4-trimethyl-1,3-pentanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Polyoxyalkylene glycol can be used. As the trivalent or higher valent alcohols, triol and tetraol such as trimethylolethane, trimethylolpropane, glycerin and pentaerythritol can be used. The aliphatic polyvalent alcohol is an alcohol
It is essential to use 60-100 mol% with respect to
Further, it is preferably used in the range of 70 to 100 mol%, and further 80 to 95 mol%. Further, as the aliphatic polyhydric alcohol, ethylene glycol, propylene glycol,
The use of 2,3-butanediol is especially preferred.

In the present invention, as the alicyclic polyvalent alcohol, 1,4-cyclohexane diol, 1,4-cyclohexane dimethanol, tricyclodecane dimethanol and tricyclodecane diol are used. Hydrogenated biphenol,
Hydrogenated bisphenol A or the like can be used. The alicyclic polyvalent alcohol is 0 to 40 mol% with respect to the alcohol component.
Can be used in the range of 5 to 30 mol%, more preferably 10 to 20 mol%. Alicyclic Geo-
It is particularly preferable to use tricyclodecane dimethanol, cyclohexane diol, or hydrogenated biphenol as the polyol.

Other polyhydric alcohols include spiroglycol, paraxyleneglycol, metaxyleneglycol, orthoxyleneglycol, 1,4-phenyleneglycol and 1,4-phenyleneglycol. -Ethylene oxide adduct, diol such as bisphenol A,
Ethylene oxide adducts and propylene oxide adducts of bisphenol A, hydrogenated bisphenol A ethylene oxide adducts and propylene oxide adducts, and as polyester polyols, lactones such as ε-caprolactone are subjected to ring-opening polymerization. The lactone-based polyester polyols and the like obtained as described above can be used within a range where there is no problem.

The glass transition point of the polyester resin in the present invention is preferably 55 ° C. or higher, 58 ° C. or higher, preferably 60 ° C. or higher, more preferably 65 ° 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, which may cause storage stability problems. The number average molecular weight of the polyester resin of the present invention is 10
The range of 00 or more and 10000 or less is preferable. Also, 20
The range of 00 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 50.
0 eq. 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,
Examples thereof include salts of K, Mg, Ca, Cu, Fe and the like, and particularly preferred 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 500 meq / 10 with respect to the polyester resin
00 g, more preferably 50-200 meq / 1000
g.

When the polyester resin of the present invention contains an ionic group, it exhibits water dispersibility. Water dispersibility means a state generally called emulsion or colloidal dispersion. The ionic group dissociates in the aqueous medium and forms an electric double layer at the interface between the polyester resin and water. When the polyester resin is present as fine microparticles in the water system, an electrostatic repulsive force is generated between the microparticles due to the action of the electric double layer, and the microparticles are stably dispersed in the water system.

For the resin particles in the present invention, for example, a polyester emulsion (or polyester dispersion) is prepared by water-dispersing an ionic group-containing polyester resin, and the water-dispersed polyester microparticles are plasticized. It can be obtained by slowly aggregating under conditions. As a method of coagulating the aqueous dispersion, there are a method of reducing the surface potential of dispersed particles, and a method of adding an electrolyte into the dispersion system to reduce the thickness of the electric double layer. As a method of reducing the surface potential of the dispersed particles, a method of releasing the ionic group contained in the polyester resin by photolysis, thermal decomposition, hydrolysis, etc., temperature, p
A method of controlling the degree of dissociation by scanning H or the like, a method of blocking an ionic group with a polyion complex, and the like can be used. As a method of adding an electrolyte to reduce the thickness of the electric double layer, a method of directly adding an inorganic salt or an organic salt, or a method of diluting and adding can be used, but as a more preferable method, amino alcohol and carvone are used. An example is a method of using a compound that secondarily generates a salt by hydrolyzing in the system, such as an ester compound with an acid. When micro-particles are slowly aggregated under a plasticized state, the particles are plasticized, and when a plurality of particles aggregate, they are spherical due to surface tension and grow into particles having a larger particle size. When particles grow in the slow aggregation region, the dispersion stability of the particles becomes higher, and the aggregation does not proceed randomly. Therefore, if the dispersibility of the particles is always kept within the slow aggregation region, particles having an arbitrary particle size can be obtained. 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 μm,
Polyester spherical particles having a particle size of 0.5D to 2.0D occupying 80% by weight or more of the whole, a coefficient of variation of 30% or less, and a sphericity (minor axis / major axis) of 0.8 or more. Becomes

As described above, the ionic group introduced into the polyester is essential for water dispersion and has a side effect of easily absorbing moisture. However, the hygroscopicity of the polyester resin is not only due to the introduced ionic groups, but also has a large hygroscopic effect due to ester bonds in the molecular chain, carboxyl groups at the molecular ends, hydroxyl groups and the like. In the present invention, the hygroscopicity of the polyester resin is lowered by blocking the carboxyl group and hydroxyl group at the molecular end by introducing a monocarboxylic acid, and practically sufficient environmental stability is achieved despite the introduction of an ionic group. To realize the sex.

The present invention is described in more detail below by referring to Examples, but the present invention is not limited thereto.

【Example】

[Synthesis of Polyester Resin] In an autoclave equipped with a thermometer and a stirrer, 134 parts by weight of dimethyl terephthalate, 37 parts by weight of dimethyl isophthalate, 5 parts of 5-sodium sulfodimethylisophthalate. 20 parts by weight of para-tert-butyl benzoic acid methyl ester, 136 parts by weight of ethylene glycol, and 0.1 parts by weight of tetrabutoxy titanate were charged and heated at 180 to 230 ° C. for 120 minutes to carry out the transesterification reaction. went. Then, the reaction system was heated to 240 ° C., and the reaction was continued for 60 minutes under the system pressure of 1 to 10 mmHg, and as a result, a copolyester resin (A01) was obtained.
The composition, glass transition temperature, acid value, molecular weight and sodium sulfonate group equivalent of the obtained copolyester resin (A01) are shown in Table 1 below. Shown in. The composition of polyester is NM
R analysis, glass transition temperature was determined by DSC, acid value was determined by titration, molecular weight was determined by GPC, and sodium sulfonate group equivalent was determined by determination of S. Then, polymerization was carried out in the same manner by changing the raw materials, and Table 1. ~ Table 2. Polyester resin (A02) shown in
(A14) was obtained.

[Production of particles] Polyester resin (A0
1) 340 parts by weight, 150 parts by weight of methyl ethyl ketone,
After dissolving 140 parts by weight of tetrahydrofuran at 80 ° C., 680 parts of water at 80 ° C. was added to obtain an aqueous microdispersion of a copolyester resin having a particle diameter of about 0.1 μm. Further, the obtained water-based microdispersion was placed in a distillation flask and distilled until the distillate temperature reached 100 ° C. After cooling, water was added to make the solid content concentration 30%. To a four-necked 1-liter separable flask equipped with a thermometer, a condenser, and a stirring blade, 300 parts by weight of the aqueous copolymer polyester dispersion was charged and the temperature was raised to 80 ° C. Then, 40 parts by weight of a 20% by weight aqueous solution of dimethylaminoethyl methacrylate was added to 6 parts.
Add over 0 minutes and continue stirring for an additional 300 minutes at 80 ° C. The conductivity in the system is about 1 mS to 2
Raised to 5 mS and the pH dropped from 10.8 to 6.7. From this, it was inferred that the added dimethylaminoethyl methacrylate was almost completely hydrolyzed later to form a salt of dimethylaminoethanol and methacrylic acid. The copolymer having a particle size of submicron order existing in the polyester water-based microdispersion grows as a united particle with time, and the average particle diameter is 6.5 μm, and the particle diameter is 0.5D to 2D. Occupancy rate of particles having a diameter of 95
%, Spherical particles of polyester having an average sphericity of 0.94 (B0
1) was obtained. The average particle size and the particle size distribution were measured using a corter counter TA2. For the sphericity, a scanning electron micrograph of the particles is used as an image processing device image.
It was measured by processing with a Gianalyzer-V1 [manufactured by Toyobo Co., Ltd.]. The obtained particles are 30 ° C and 95% R
The moisture absorption rate after standing for 48 hours in the environment of H was measured by a Cal-Fisher type moisture content meter. Similarly, spherical polyester particles (B02) to (B14) were obtained from the polyester resins (A02) to (A14). The results are shown in Table 1.
Table 2. Shown in. In addition, Table 1. In Table 2, TBBA is tert-butyl benzoic acid NDC is 1,5-naphthalenedicarboxylic acid TPA is terephthalic acid IPA is isophthalic acid SIP is 5-sodium sulfoisophthalic acid MA is maleic acid TMA is trimellitic acid EG is ethylene glycol PG Is propylene glycol NPG is neopentyl glycol CHD is cyclohexanediol HBPA is hydrogenated bisphenol A TCDD tricyclodecane dimethanol BPE is ethylene oxide adduct of bisphenol A (average molecular weight 350) Tg is glass transition Indicates the temperature.

[0020]

[Effect] As described above, the spherical particles in the present invention are particles of a polyester resin which is a condensation polymer, have a sharp particle size distribution with an arbitrary particle size, and have a high temperature. It has excellent characteristics that it absorbs little moisture even in a high humidity environment.

[0021]

[Table 1]

[0022]

[Table 2]

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

Claims (1)

[Claims] 1. A) an aromatic dicarboxylic acid 60 to 98 mol% b) an acid component containing an aromatic monocarboxylic acid 2 to 25 mol%, and c) an aliphatic polyhydric alcohol 60 to 100 mol% d ) Obtained by condensation of an alcohol component containing 0 to 40 mol% of alicyclic polyvalent alcohol, and
20-500 eq. / Ton is the main component of the polyester resin containing an ionic group, the volume average particle diameter D
Is 1 to 100 μm, particles having a particle diameter of 0.5D to 2.0D account for 80% by weight or more of the whole, and the average sphericalness (minor axis / major axis) is 0.8 or more.