JPH0713191B2 - Resin particles and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to micron-order resin particles having a spherical shape and a narrow particle size distribution, and a method for producing the same.

(Prior Art) In recent years, polymer beads have been widely used as matting agents, antiblocking agents, organic pigments, chromatography carriers, drug carriers, powder coatings, thickness gap adjusting materials, toners, and the like. The polymer beads used for such applications have a particle size of 0.1 to 100 μm, are spherical, and are required to have a narrow particle size distribution.

Conventionally known as a method for producing such polymer beads is a so-called suspension polymerization method in which a special suspension stabilizer is used or a vinyl monomer is dispersed and polymerized under high-speed stirring.

(Problems to be solved by the invention) However, in the polymerization method by the suspension method, the polymerization is carried out in a stable suspension system without coalescence, and particles having a uniform particle size distribution by the polymerization (especially 20 μ or less) It is technically difficult to get.

Therefore, sparingly soluble inorganic powders such as BaSO ₄ , MgCO ₃ talc, clay, and water-soluble polymers such as polyvinyl alcohol and gelatin starch are added as suspension stabilizers to the polymerization system to prevent coalescence of polymer particles. However, there is a drawback that the particles become smaller than necessary, or particles cannot be obtained by gelling, and even if gelation can be prevented, the particle size distribution is broad and classification after polymerization is performed. Operation is required.

Polycondensation type resins such as polyesters and polyamides, polyaddition type resins such as polyurethanes cannot form particles by means of suspension polymerization, and therefore, the resin is dissolved in a solvent to obtain the solution. It is possible to consider a method in which the compound is dropped into a precipitating agent to solidify, but it is difficult to form substantially spherical particles by such a method, and a solvent recovery step is required.

(Means for Solving the Problems) An object of the present invention is to provide resin particles which are substantially spherical and have an arbitrary particle size and a narrow particle size distribution, and an industrial production method thereof.

The present inventors have conducted extensive studies to achieve the above object, and as a result, by using resin particles composed of an ionic group-containing resin (A) and a counterionic group-containing vinyl polymer (B) of the resin (A). Further, the resin particles can industrially achieve the object of the present invention by polymerizing the vinyl monomer (b) containing a counterionic group of the resin (A) in an aqueous dispersion of the resin (A) fine particles. They have found that they can obtain the present invention and have reached the present invention. That is, the present invention comprises an ionic group-containing resin (A),
Vinyl polymer (B) containing counter ion group of resin (A)
The resin particles are characterized by having a spherical shape having as a main component, a spherical resin particle group consisting of the resin particles, the average particle diameter (D) is 0.1 ~ 100μm,
And the resin particles, characterized in that 70 wt% or more particles are present in the range of 0.5D ~ 2.0D, further spherical resin particle group consisting of the resin particles, the sphericity is 0.7 or more. Of the resin (A) in the fine particle water-based dispersion of the ionic group-containing resin (A). A method for producing resin particles, which comprises polymerizing a vinyl monomer (b), wherein an equivalent ratio of the amount of counter ionic groups in the polymer (B) to the amount of ionic groups in the resin (A) is 0.5 to 10 Is a method for producing resin particles in the above-mentioned production method, wherein the monomer (b) is polymerized so that

Here, the ionic group is an anionic group such as a carboxyl group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group or salts thereof, or a cationic group such as a primary to tertiary amino group, The counter ionic means an ionic group opposite to the ionic group (a cationic group when the ionic group is an anionic group, and an anionic group when the ionic group is a cationic group). The ionic group may be introduced by a surfactant or the like, not only when it is contained in the resin (A) as a bond.

Such an ionic group is essential for forming a stable aqueous dispersion of resin (A) fine particles having an average particle size of less than 0.1 μm, and the amount thereof is not limited as long as the aqueous dispersion can be obtained. However, a suitable range is approximately 20 to 500 equivalents / 10 ⁶ g. When the particle size of the resin (A) fine particles is 1 μm or more, it becomes difficult to obtain resin particles having a substantially spherical shape and a narrow particle size distribution.

The amount of the counter ionic groups is 0.5 in terms of an equivalent ratio of the amount of the ionic groups in the polymer (B) to the amount of the ionic groups in the resin (A).
-10 is preferably 0.7 to 5.0, more preferably 0.8 to 3.0. If the lower limit of the range is not reached, coalescence and growth of the fine particles are less likely to occur, and if the upper limit is exceeded, not only does it not contribute to the growth of the fine particles but also water resistance of the resin particles may deteriorate.

The polymerization initiator used for polymerizing the vinyl monomer (b) is not particularly limited, and examples thereof include organic peroxides such as benzoyl peroxide and acetyl peroxide; 2,2′-azobisisobutyronitrile, 2 , 2'-Azobis (azo compounds such as 2,4-dimethylvaleronitrile; inorganic peroxides such as persulfate, hydrogen peroxide, and permanganate; inorganic peroxides and sulfites, bisulfites, Metasulfites, hydrosulfites, thiosulfates, iron salts, water-soluble redox initiators with reducing agents such as oxalic acid, and the like, but from the viewpoint of safety and industrial viewpoint, water-soluble redox initiators are preferable. The amount of the polymerization initiator used is approximately 0.1 to 3 with respect to the vinyl monomer (b).
It is within the range of weight%.

Although it is difficult to unambiguously specify the polymerization temperature, the resin (A) fine particles dispersed in the aqueous medium are combined with the polymerization of the vinyl monomer (b) to grow spherically. It is desirable to adopt a temperature condition equal to or higher than the glass transition point (Tg) of (1), and amorphous particles are easily generated under the temperature condition lower than the temperature. In addition, by using a solvent and a plasticizer for the resin (A) together, the apparent appearance of the resin (A)
It is also possible to lower Tg (or the minimum film forming temperature) and polymerize under the conditions of such temperature or higher. The type of the solvent and the plasticizer is not limited, and may be appropriately selected from known ones depending on the type of the resin (A) as long as the polymerization is not excluded.

Other polymerization conditions are carried out according to a conventional method, but the means for preliminarily charging the vinyl monomer (b) into the aqueous dispersion of the resin (A) fine particles and then dropping the polymerization initiator is the resin (A) fine particles. It is preferable because there is no problem such as rapid coalescence and aggregation.

The obtained aqueous dispersion of resin particles is taken out as a dry powder according to a conventional method such as filtration, freeze-drying or spray-drying.

When the vinyl monomer (b) is a cationic-containing vinyl monomer (hereinafter referred to as a cationic monomer), for example, 2-aminoethyl (meth) acrylate, 2-N, N
-Dimethylaminoethyl (meth) acrylate, 2-N,
N-diethylaminoethyl (meth) acrylate, 2-
N, N-dipropylamino (meth) acrylate, 2-N, t
-Butylaminoethyl (meth) acrylate, 2- (4
-Morpholino) -ethyl (meth) acrylate, 2-vinylpyridine, 4-vinylpyridine, aminostyrene, and the like, and examples of the anionic group-containing vinyl monomer (hereinafter anionic monomer) include (meth) acrylic acid, Itaconic acid, frotonic acid, maleic acid, monomers containing a carboxyl group such as fumaric acid or a salt thereof, styrenesulfonic acid, vinyltoluenesulfonic acid, vinylethylbenzenesulfonic acid, isopropenylbenzenesulfonic acid, 2-chlorostyrenesulfonic acid, 2,4-dichlorostyrenesulfonic acid, 2-methyl-4-chlorostyrenesulfonic acid, vinyloxybenzenesulfonic acid, vinylsulfonic acid, (meth) allylsulfonic acid, (meth)
Sulfoethyl or sulfopropyl esters of acrylic acid, monomers containing sulfonic acid groups such as 2-acrylamido-2-methylpropanesulfone or salts thereof, azidophosphoxyethyl (meth) acrylate, azidophosphoxypropyl (meth) acrylate, 3 -Chloro-
Examples thereof include monomers containing a phosphoric acid group such as 2-azidophosphoxypropyl methacrylate, bis (meth) acryloxyethyl phosphate, and vinyl phosphate or salts thereof. In order to achieve the object of the present invention,
The combination of the anionic group-containing resin (A) and the cationic monomer is more desirable. Further, it is possible to appropriately use a known nonionic monomer in combination.

Thus, resin particles having an average particle diameter (D) of any size in the range of 0.1 to 100 μm and 70% or more of particles in the range of 0.5D to 2D are industrially produced. can do. The particle diameter can be easily controlled by the equivalent ratio of the amount of ionic groups of the vinyl polymer (B) to the amount of ionic groups in the resin (A), the polymerization temperature, the polymerization time, and the like. The resin particles can be made large by a means such as increasing the ratio within the range of 0.5 to 10, increasing the polymerization temperature, and lengthening the aging time.

In consideration of the industrial polymerization conditions of the vinyl monomer (b), it is desirable that the resin (A) has a Tg in the range of 30 to 90 degrees, from the viewpoint of improving the sphericity of particles and shortening the aging time. It is desirable to set the polymerization temperature to Tg + 10 ° C or higher. Thus, resin particles having a sphericity of 0.7 or more and a number average of 70% or more are formed.

The type of the resin (A) is not limited, and examples thereof include polycondensation resins such as polyester and polyamide resins, and polyaddition resins such as polyurethane resins and polyurea resins.

(Examples) Hereinafter, the present invention will be described more specifically with reference to Examples.
The invention is not limited in scope by the description of these examples.

Parts and percentages shown in the examples are based on weight unless otherwise specified. The average particle diameter was measured by Shimadzu Corporation's automatic particle size distribution measuring device CAPA700, and the sphericity was measured by an optical microscope. The sphericity is defined as the ratio of the diameters, where 1.0 is a true sphere, and 1.0 is a deformed one.
Further, the molecular weight was measured by Hitachi Model 115 molecular weight measuring device, and the particle size of the dispersion was measured by a grindometer and an optical microscope.

Examples 1 to 6 and Comparative Examples 1 and 2 Production of Polyester Resin Fine Particle Aqueous Dispersion 95 parts of dimethyl terephthalate, dimethyl isophthalate
95 parts, ethylene glycol 68 parts, neopentyl glycol 114 parts, zinc acetate 0.1 parts were charged into a reaction vessel, and the temperature was 140 ° C to 2 ° C.
After transesterification at 20 ° C for 3 hours, 5.4 parts of 5-sodium sulfoisophthalic acid was added and esterification reaction was performed at 220 to 260 ° C for 1 hour, and then at 200 to 260 ° C under reduced pressure (10 to 0.2 mmHg). Polycondensation reaction for 1 hour at molecular weight 2
A polyester resin (A) having a Tg of 700 and a Tg of 55 ° C. (sodium sulfonate base amount: 104 equivalents / 10 ⁶ g) was obtained.

34 parts of this polyester resin, 10 parts of butyl cellosolve
After dissolving at 0 ° C, add 56 parts of water at 80 ° C to obtain a particle size of 0.1μ
A polyester aqueous dispersion (I) was obtained.

1000 parts of water dispersion (I) was placed in a distillation flask, distilled until the distillate temperature reached 100 ° C., cooled, 250 parts of deionized water was added, and an aqueous dispersion containing no butyl cellosolve (II) Got

Manufacture and evaluation of resin particles Four-port one equipped with thermometer, condenser and stirring blade
In a separable flask, 834 parts of water-based dispersion, deionized water 35
And the cationic monomer (b) monomer shown in Table 1 were added and the temperature was raised to the temperature shown in Table 1. Next, 100 parts of an aqueous solution containing 0.2 part of ammonium persulfate was added dropwise over 40 minutes, and then the temperature was maintained during the aging time shown in Table 1.

Then, the dispersion liquid was subjected to a spray dryer to obtain resin particles.

Table 1 also shows the evaluation results of the particle shape, particle size, and the like.

From Table 1, it can be seen that by controlling the equivalent weight of the cationic group, the polymerization temperature, and the aging time, resin particles having a spherical shape and a narrow particle shape distribution and having an arbitrary average particle diameter can be obtained.

(Effect of the Invention) According to the present invention, it is presumed that the resin (A) fine particles stabilized by an ionic group are associated, united or spheroidized through the vinyl polymer (B) having a counterionic group. To be done.

Thus, the average particle size is controlled to any size within the range of 0.1 ~ 100μ, it is possible to industrially provide resin particles having a substantially spherical and narrow particle size distribution, the present invention is of special note. It should be an effect.

The obtained resin particles are a matting agent, an anti-blocking agent thickness gap adjusting material, a chromatography carrier, a drug carrier,
Widely used in various applications such as organic pigments, powder-to-paint and toner.

Claims (5)

[Claims] 1. A main component is a polycondensation type ionic group-containing resin (A) such as polyester type or polyamide type and a counterionic group containing vinyl polymer (B) of the resin (A). The weight ratio of (A) to (A) + (B) is 0.
Resin particles having a size of 8 or more and having a spherical shape. 2. A spherical resin particle group consisting of the resin particles according to claim 1, having an average particle diameter (D) of 0.1 to 100 μm,
Further, the resin particles are characterized in that 70% by weight or more of particles are present within the range of 0.5D to 2.0D. 3. A spherical resin particle group consisting of the resin particles according to claim 1, wherein 70% or more of particles having a sphericity of 0.7 or more are present in a number average of 70% or more. 4. Polymerization of a vinyl monomer (b) containing a counterionic group of a resin (A) in a fine particle aqueous dispersion of a polycondensation type ionic group containing resin (A) such as a polyester type or a polyamide type. A method for producing resin particles, comprising: 5. The amount of counterionic groups in the counterionic group-containing vinyl polymer (B) is equivalent to the amount of ionic groups in the polyester- or polyamide-based polycondensation-type resin (A). The method for producing resin particles according to claim (4), wherein the vinyl monomer (b) containing a counterionic group is polymerized so that the ratio becomes 0.5 to 10.