JPH07268019A - Production of vinyl chloride resin for paste technique - Google Patents

Abstract

PURPOSE:To obtain a vinyl chloride resin having a good dispersibility in a good yield using a small quantity of an organic liquid by adding an organic liquid as a W/O emulsion to an aqueous dispersion of a vinyl chloride resin for paste technique. CONSTITUTION:A method for separating and recovering a vinyl chloride resin as an aggregate from an aqueous phase by mixing an aqueous dispersion of a vinyl chloride resin for paste technique with an organic liquid which is hardly soluble in water and neither dissolves the vinyl chloride resin nor allows it to swell, wherein a water-in-oil(W/O) emulsion is used as the organic liquid. By this method, the quantity of the organic liquid necessary for obtaining vinyl chloride resin particles as an aggregate can be reduced and the dispersion of the vinyl chloride resin in a plastisol can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for producing a vinyl chloride resin for paste processing. More specifically, the present invention provides a water-in-oil type (W / O type) of a vinyl chloride resin powder for paste processing, which is easily disentangled into powder particles from a vinyl chloride resin aqueous dispersion and has good dispersibility.
The present invention relates to a method for producing using an emulsion.

[0002]

2. Description of the Related Art Paste processing is one of the important processing methods for vinyl chloride resin. For the paste processing of vinyl chloride resin, the vinyl chloride resin produced for paste processing is mixed with a plasticizer, a stabilizer, and, if necessary, a compounding agent such as a pigment and a filler to form a liquid plastisol. A molded product is obtained by shaping a liquid plastisol by means such as casting, coating, and dipping and heating and melting and solidifying it. Therefore, the vinyl chloride resin for paste processing has a very fine particle size, disperses in the plasticizer, does not freely perform Brownian motion, and does not settle, has an appropriate particle size distribution, has a smooth surface and is dense inside. Spherical particles, that when dispersed with a plasticizer, it can be easily dispersed without agglomeration to form a stable sol, that it does not swell in the plasticizer at room temperature, its aging viscosity change is small, and it melts at high temperatures. Requires various performances such as easy and rapid gelation. Further, in the vinyl chloride resin for paste processing, usually a large number of single particles are aggregated to form a resin particle powder, but this aggregate needs to be loosened into single particles in the plastisol, so if it is coarse If they remain as particles, they not only affect the fluidity of plastisol, but also cause problems such as clogging during transport of plastisol, scoring during coating, and the surface of the molded product when formed into a molded product. It causes inconveniences such as roughening of the skin and deterioration of gloss, and further deterioration of strength of the molded product. In order to prevent such problems in paste processing,
The resin powder used for this is usually Tyler sieve 325.
It is supplied as a fine powder like the whole mesh. As a method for producing the resin for this purpose, a particle size of 0 is obtained by emulsion polymerization or fine suspension polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride in the presence of a radical-generating type polymerization initiator and an emulsifier. A method of obtaining an aqueous dispersion of a spherical resin having a diameter of 0.05 to 5 μm and spray-drying this aqueous dispersion has been adopted, but a large amount of energy is required to evaporate and dry water. Further, since the conventional resin obtained by such a method is a fine powder, it not only causes a deterioration of the work environment such as powder scattering at the time of bag packaging of the product and bag opening and mixing at the time of plastisol production. In addition, because of poor powder fluidity, automatic weighing and automatic transportation are difficult. In order to solve the current problems of the paste processing resin, a vinyl chloride resin from an aqueous dispersion of the paste processing vinyl chloride resin is an organic solvent that is hardly soluble in water and does not dissolve or swell the vinyl chloride resin. A method of recovering the vinyl chloride resin by adding a liquid to the aqueous dispersion to separate the vinyl chloride resin as an aggregate from the aqueous phase, and recovering the vinyl chloride resin as it is or by granulating it and drying it -4228
It is proposed in Japanese Patent Publication No. However, although various problems have been tentatively improved by this method, the cohesion of the wet resin aggregate after dehydration is strong, the occurrence of blocking in the drying step, the non-uniformity of drying, and the presence of coarse particles of the molded product. There is a problem such as the occurrence of granular projections on the surface,
The recovery rate of the resin powder was only about 96%, and the recovery loss of 4% was serious for mass-produced resin, and it was necessary to recover the resin remaining in the separated aqueous phase. In particular, there is a problem that the yield of the resin aggregate decreases when the amount of the organic liquid used is reduced, and it is desired to develop a method capable of forming a vinyl chloride resin aggregate for paste processing with a small amount of the organic liquid. It was

[0003]

Under these circumstances, the present invention provides a vinyl chloride resin for paste processing, which is easily disentangled into powder particles from an aqueous dispersion of vinyl chloride resin and has good dispersibility. The object of the present invention is to provide a method for producing a good yield using a small amount of organic liquid.

[0004]

As a result of intensive studies to achieve the above object, the present inventor has found that as an organic liquid to be added to an aqueous dispersion of a vinyl chloride resin, a water-in-oil type (W / It was found that a vinyl chloride resin aggregate having good performance can be obtained in good yield by using an (O-type) emulsion, and the present invention was completed based on this finding. That is, the present invention is an aqueous dispersion of a vinyl chloride resin for paste processing, by adding an organic liquid that is sparingly soluble in water and does not dissolve or swell the vinyl chloride resin into an aqueous phase of the vinyl chloride resin as an aggregate. In the method of further separating and collecting, the organic liquid is water-in-oil type (W /
It is intended to provide a method for producing a vinyl chloride resin for paste processing, which is an O-type) emulsion.

In the method of the present invention, basically, the first step for preparing an aqueous dispersion of vinyl chloride resin, the aqueous dispersion obtained in the first step are introduced into a batch type tank mixer, and the water-in-oil type is used. (W
/ O type) as a binder, the second step of assembling the vinyl chloride resin, the third step of separating and collecting the vinyl chloride resin aggregate from the aqueous dispersion of the vinyl chloride resin aggregate, and the recovered vinyl chloride resin Fourth to dry the aggregate
It consists of steps. The aqueous dispersion of the vinyl chloride resin for paste processing used in the present invention is mainly composed of a vinyl chloride homopolymer produced by ordinary emulsion polymerization or fine suspension polymerization, or vinyl chloride (usually 70% by weight). Above) copolymers, that is, vinyl chloride and vinyl acetate, vinylidene chloride, ethylene, propylene, butene,
Acrylonitrile, acrylic acid ester, methacrylic acid ester or an aqueous dispersion of a copolymer with a monomer such as maleic acid, which can be used without any limitation as long as it can be subjected to ordinary paste processing it can. The aqueous dispersion of vinyl chloride resin used in the present invention usually contains about 10 to 70% by weight of vinyl chloride resin. As such an aqueous dispersion, an aqueous dispersion of a vinyl chloride resin after completion of polymerization may be used as it is, or may be partially dehydrated or water may be added if necessary. Content of vinyl chloride resin is 10% by weight
If it is less than 1, the waste water amount becomes too large compared to the product amount and it is uneconomical. If the content of vinyl chloride resin exceeds 70% by weight, an aqueous dispersion and a water-in-oil type (W / O type) emulsion are obtained. The viscosity of the mixed solution of (1) remarkably increases, which makes operation difficult.

In the method of the present invention, an organic liquid which is sparingly soluble in water and which does not dissolve or swell the vinyl chloride resin during separation and recovery of the vinyl chloride resin is a water-in-oil type (W / O type) emulsion. Used. As such an organic liquid, a liquid having a melting point of 20 ° C. or lower and a boiling point at normal pressure of not lower than the temperature at the time of separation and recovery of the present invention, preferably 200 ° C. or higher is desirable. When an organic liquid having a boiling point lower than the temperature at the time of separation and recovery is used,
A pressure vessel is used to prevent volatilization of this organic liquid, additional equipment is required to collect the volatilized organic liquid, and it is easy to keep the amount of organic liquid in the vinyl chloride resin constant. It is not preferable because it disappears. Of course,
Even if the above-mentioned conditions are not satisfied as a single product, it can be used as long as it is a mixture of two or more kinds of liquids and has the above-mentioned requirements. The organic liquid used in the present invention is required to be sparingly soluble in water for the following two reasons. First, after mixing with the aqueous dispersion, to reduce the amount of entrainment in the aqueous phase to be separated to prevent loss of organic liquid and reduce wastewater treatment costs,
Secondly, in order to collect the vinyl chloride resin particles dispersed in water via the organic liquid, it is necessary that the organic liquid is present on the particle surface between the resin particles and water. Further, when the organic liquid used in the present invention dissolves or swells the resin at the temperature at the time of separation and recovery in the present invention, the resin particles are deformed and deteriorated, which is inconvenient. Since most of the organic liquid used in the present invention remains in the product resin, it should be avoided that it adversely affects the operability and processability during paste processing and the quality of the molded product. From the above points, it is most natural and rational to use the liquid compounding agent which is usually used for paste processing as the organic liquid.

In the method of the present invention, the organic liquid is added to the aqueous dispersion of vinyl chloride resin as a water-in-oil type (W / O type) emulsion. Since the vinyl chloride resin particles in the aqueous dispersion are aggregated by interposing the organic liquid on the surface, if the amount of the organic liquid used is small,
Vinyl chloride resin particles to which the organic liquid does not adhere are left on the surface, and such particles are not collected as an aggregate, which reduces the yield of the vinyl chloride resin for paste processing. On the other hand, the organic liquid used for assembling the vinyl chloride resin particles is finally contained in the vinyl chloride resin for paste processing, and is selected from the liquid compounding agents usually used for paste processing. However, vinyl chloride resin for paste processing has a wide variety of uses such as paste coated vinyl leather, vinyl foamed leather, dip coating, slush molding, rotational molding, and vinyl chloride resin coated steel sheet, and the optimum formulation is selected for each. Therefore, from the viewpoint of increasing the degree of freedom in selecting the formulation, it is desirable that the specific organic liquid contained in the vinyl chloride resin for paste processing be as small as possible. further,
The smaller the amount of the organic liquid contained in the vinyl chloride resin for paste processing, the better the dispersibility of the vinyl chloride resin in preparing the plastisol. In the method of the present invention,
Since the organic liquid is added to the aqueous dispersion of the vinyl chloride resin as a water-in-oil (W / O type) emulsion, the water content in the emulsion increases the volume of the organic liquid, and the emulsification of Since the total volume increases remarkably, the adhesion effect of the vinyl chloride resin particles in the aqueous dispersion to the surface becomes large, and the vinyl chloride resin can be used with a much smaller amount of the organic liquid than when the organic liquid is added alone. The aggregation of particles can be efficiently achieved. It is difficult to reduce the amount of the organic liquid by the conventional method of directly adding the organic liquid to the aqueous dispersion of the vinyl chloride resin, and it is difficult to reduce the amount of the organic liquid to 100 parts by weight of the vinyl chloride resin in the aqueous dispersion. If the amount is 3 parts by weight or less, the yield of vinyl chloride resin is lowered. Furthermore, by adding the organic liquid as a water-in-oil type (W / O type) emulsion, the dispersibility of the resin in the plastisol becomes good. In the method of the present invention, the amount of the organic liquid used as a water-in-oil type (W / O type) emulsion is 0.1 to 5 parts by weight, preferably 1 to 3 parts by weight, per 100 parts by weight of the vinyl chloride resin. is there. The amount of organic liquid used is 0.1
If it is less than 5 parts by weight, the aggregate of vinyl chloride resin in the aqueous dispersion is insufficiently formed, and if the amount of the organic liquid used exceeds 5 parts by weight, vinyl chloride resin powder adheres to the empty duct. Or the vinyl chloride resin aggregate becomes hard and the dispersibility becomes poor at the time of preparing the paste, which is not preferable. The content of water in the water-in-oil (W / O type) emulsion of the organic liquid is 20 to 50% by volume, preferably 20 to 40% by volume.

In the method of the present invention, as the organic liquid,
For example, the following plasticizers, process oils and lubricants can be used. (1) Alkyl phthalate plasticizers such as dioctyl phthalate, dinonyl phthalate, butyl lauryl phthalate and methyl oleyl phthalate. (2) Aromatic carboxylic acid ester plasticizers such as trioctyl trimellitate and diethylene glycol dibenzoate. (3) Aliphatic dibasic acid ester plasticizers such as dioctyl adipate, dibutyl sebacate, and dioctyl tetrahydrophthalate. (4) Phosphate ester plasticizers such as trioctyl phosphate and trichloroethyl phosphate. (5) Fatty acid glycol ester-based plasticizer such as diethylene glycol dicaprylate and 1,4 butylene glycol-di-2-ethylhexanoate. (6) Polyester plasticizer. (7) Fatty acid ester type such as butyl oleate, methyl acetylricinoleate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, epoxidized soybean oil, epoxy type such as octyl epoxystearate, chlorine Secondary plasticizers based on chlorinated paraffins such as methylated fatty acid methyl and chlorinated paraffins, and aliphatic dibasic acid ester such as dioctyl succinate. (8) Petroleum-based diluents such as mineral spirits and mineral terpenes, and long-chain alkylbenzene-based diluents such as dodecylbenzene. (9) Liquid lubricants such as higher alcohols, liquid paraffin, and higher fatty acid alkyl esters.

The method of preparing the water-in-oil type (W / O type) emulsion of the organic liquid used in the method of the present invention is not particularly limited and can be prepared by any method.
The water-in-oil type (W / O type) emulsion is an oily organic liquid in which fine water droplets are dispersed. Generally, the method of preparing an emulsion that is industrially used includes a method of performing natural emulsification in the state of a self-emulsifying oil or a solubilized oil, and a mechanical method such as a homogenizer, a colloid mill, a flow jet mixer, and an ultrasonic emulsifier. Although there is a forced emulsification method in which emulsification is performed by using a means, the forced emulsification method is preferable in order to make emulsion particles fine and to stabilize. Whether the emulsion type is the water-in-oil type (W / O type) or the oil-in-water type (O / W type) is governed by various factors. Among them, the effect of the emulsifier is large and generally A liquid phase in which a large amount of emulsifier is dissolved tends to become a continuous phase. Therefore, it is preferable to use a lipophilic nonionic surfactant having a small HLB value for the preparation of the water-in-oil type (W / O type) emulsion used in the method of the present invention. For example, when diisononyl phthalate is used as the organic liquid, HLB is 8.
It is desirable to use a sorbitan monolaurate of 6 or a nonionic surfactant having an HLB of 8.6 or less.

In the preparation of the water-in-oil type (W / O type) emulsion used in the method of the present invention, 0.5 to 10% by weight, preferably 1 to 7% by weight, based on the organic liquid.
Nonionic surfactants are used. When the amount of the nonionic surfactant used is less than 0.5% by weight, a stable emulsion cannot be formed, which is not preferable. Further, if the amount of the nonionic surfactant used exceeds 10% by weight, the thermal stability of the vinyl chloride resin will deteriorate and the molded product will be colored, which is not preferable. It can be easily known whether the type of emulsion obtained by the preparation is the water-in-oil type (W / O type) or the oil-in-water type (O / W type).
For example, when one droplet of the emulsion is dropped on the water surface, it can be determined that it is an oil-in-water type (O / W type) if it spreads over the entire surface and a water-in-oil type (W / O type) if it solidifies on the water surface. Alternatively, if an oil-soluble dye is added and the color spreads over the whole, it is a water-in-oil type (W / O type) emulsion, and if a water-soluble dye is added and the color spreads over the whole, an oil-in-water type ( O / W
Type) emulsion. Further, the type of the emulsion can be determined by measuring the electric conductivity of the emulsion obtained by the preparation. In the method of the present invention, a hydrophilic nonionic surfactant can be further added to the prepared water-in-oil type (W / O type) emulsion. A water-in-oil type (W / O) emulsion is more stable by adding a hydrophilic nonionic surfactant with gentle stirring after the formation of a water-in-oil type (W / O type) emulsion. Be converted. The nonionic surfactant to be added preferably has an HLB of about 10 to 15, and the addition amount thereof is 0.
About 1 to 5% by weight is desirable. The more hydrophilic anionic surfactant is not preferable because it easily causes phase inversion of a water-in-oil type (W / O type) emulsion into an oil-in-water type (O / W type) emulsion. The water of the water-in-oil type (W / O type) emulsion used in the method of the present invention may be pure water or an aqueous solution in which a suitable solute is dissolved. For example, water-in-oil type (W / O
The recovery rate of the vinyl chloride resin can be increased by dissolving an appropriate coagulant in the water of the emulsion of type (1). Examples of the aggregating agent include an inorganic low molecular aggregating agent, an inorganic polymer aggregating agent, an organic polymer nonionic aggregating agent, and an organic polymer anionic aggregating agent. These aggregating agents may be used alone or in combination of two or more, and the addition amount thereof is usually an aqueous dispersion of vinyl chloride resin and a water-in-oil type (W / O type) emulsion. 10 to 1000 ppm relative to the total weight of
Chosen to be. By adding the coagulant, the yield of the vinyl chloride resin aggregate is improved, and the wet cake obtained by the aqueous phase separation in the next step is easily loosened.

In the method of the present invention, a batch type tank mixer can be preferably used for mixing the aqueous dispersion of the vinyl chloride resin for paste processing and the water-in-oil type (W / O type) emulsion. . As the batch type tank mixer, a known mixer having a stirrer or a baffle plate is used. Since the degree of mixing has a great influence on the aggregation efficiency of the water-in-oil type (W / O type) emulsion of vinyl chloride resin, the mixing power per unit volume of the mixer is preferably 1 kW /
m ³ or more, product with mixing time is 4 kW · Hr / m
It is preferably ³ or more. In the method of the present invention,
In a batch-type tank mixer, a mixed liquid of an aqueous dispersion of vinyl chloride resin and a water-in-oil type (W / O type) emulsion is usually 20 to 70 ° C., and the organic liquid used is vinyl chloride resin. Stirring is performed at a temperature at which the vinyl chloride resin is not dissolved or swollen, but the higher the temperature, the more easily the vinyl chloride resin is swollen by the organic liquid, so stirring and mixing at 50 ° C. or lower is advantageous. By such an operation, the particle size is 50 to 500 μm,
It is possible to form a granular aggregate having an average of 100 to 300 μm. If this temperature exceeds 70 ° C., the organic liquid is absorbed by the vinyl chloride resin, and the vinyl chloride resin may soften and coalesce, and the final product may no longer be suitable for paste processing. Next, in order to separate and collect the vinyl chloride resin aggregate collected through the water-in-oil type (W / O type) emulsion from the aqueous phase, a known method such as a particle diameter depending on the shape of the aggregate is used. A vacuum dehydration method or a centrifugal dehydration method using a filter cloth, a wire net or the like by utilizing the difference, or a centrifugal sedimentation separation method utilizing the difference in specific gravity can be used.

The aspects of the present invention will be listed below. (1) To an aqueous dispersion of vinyl chloride resin for paste processing,
In a method of recovering the vinyl chloride resin as an aggregate by separating from the aqueous phase by adding an organic liquid that is poorly soluble in water and does not dissolve or swell the vinyl chloride resin,
A method for producing a vinyl chloride resin for paste processing, wherein the organic liquid is a water-in-oil type (W / O type) emulsion. (2) The method for producing a vinyl chloride resin for paste processing according to the above (1), wherein the amount of the organic liquid used is 0.1 to 5 parts by weight per 100 parts by weight of the vinyl chloride resin for paste processing. (3) The amount of the organic liquid used is 1 to 3 parts by weight per 100 parts by weight of the vinyl chloride resin for paste processing.
A method for producing a vinyl chloride resin for paste processing according to claim 1. (4) The organic liquid contains a lipophilic nonionic surfactant of 0.5 to 0.5.
The method for producing a vinyl chloride resin for paste processing according to the above (1) to (3), which contains 10% by weight. (5) Production of vinyl chloride resin for paste processing according to the above (4), wherein a water-in-oil type (W / O type) emulsion is stabilized with 0.1 to 5% by weight of an organic liquid, a hydrophilic nonionic surfactant. Method.

The vinyl chloride resin aggregate separated in the separation step is then sent to the drying step to remove the attached water. In this drying step, it is necessary to set conditions that do not impair the dispersibility during paste processing. That is, the temperature of the vinyl chloride resin during the drying step is usually 70 ° C. or lower, preferably 50 ° C. or lower. That is, the conditions are selected so that the granularity in a state close to the particle size distribution of the formed vinyl chloride resin aggregate is reproduced.
As a drying device, it is preferable to use a reduced pressure stirring dryer in order to keep the temperature of the material to be dried low.Moreover, if the particle size of the resin is relatively uniform, low temperature drying, in order to improve the operating efficiency, flow A floor dryer is suitable, but widely known dryers can be used. In the drying process, it is possible to obtain a resin with an indeterminate shape or a wide particle size distribution as a product by selecting an appropriate device, but by incorporating a pellet forming machine such as an extrusion-type granulator in the process, particles can be obtained. It is also possible to homogenize the shape. Also in this case, the resin should not be melted or absorb the organic liquid due to heat or pressure during granulation, and the dispersibility during paste kneading should not be impaired.

[0014]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The properties in the examples and comparative examples were determined by the following methods. (1) Solid-Liquid Separation Good: The resin aggregate is firmly formed, and when the aqueous dispersion of granular resin is vacuum-filtered using a filter cloth with an aeration rate of 80 ml / sec · cm ² , solid-liquid separation is promptly performed. Done. X: The resin aggregate is not sufficiently formed and is creamy, and the filter cloth is clogged, and filtration is difficult. (2) Sol dispersion characteristics 50 g of resin and 30 g of di-2-ethylhexyl phthalate
The particle size of resin particles in the sol NF (North Fine Gauging)
e) was measured. Place the sol on the base line at the maximum depth position of a 0.5 inch wide steel gauge where the groove depth changes linearly, and pull the sol toward the shallow side with a scraper,
Read the locations where large numbers of coarse particles appear as dots. 0 is the coarsest and 8 is the finest. This numerical value 8 corresponds to a particle size of 0, 4 is a particle size of 51 μm, and 0 is a particle size of 102 μm. The larger the NF value, the finer the particles and the better the dispersion. (3) Recovery rate

[Equation 1]

Example 1 In a 300 ml container, 100 g of diisononyl phthalate and a lipophilic nonionic surfactant [Reodol S manufactured by Kao Corporation]
P-L10, sorbitan monolaurate] 5 g,
Mix for 3 minutes on a high speed mixer. Then, 50 g of water was added and mixed for 10 minutes to obtain a water-in-oil type (W / O type) emulsion. The aqueous dispersion of the vinyl chloride resin for paste processing was passed through a screen having a wire mesh of 250 μm open in advance, and water was added to the aqueous dispersion that had passed through to adjust the solid content to 35% by weight. Next, 11 kg of the prepared aqueous dispersion of vinyl chloride resin (resin content 385
0 g) was placed in a tank-type mixer having a diameter of 20 cm and an internal capacity of 12 liters, and the stirring was started at 1100 rpm. At the same time, 3.5 g of the water-in-oil type (W / O type) emulsion was added from the bottom of the mixer. For 35 minutes. Then, the mixture was further stirred and mixed at 1100 rpm for 90 minutes to obtain an aqueous dispersion of granular resin. The dispersion was vacuum filtered using a filter cloth having an air flow rate of 80 ml / sec · cm ² to separate the granular resin, and 6530 g of wet granular resin was obtained. When this was dried with a small fluid dryer, 3890 g
Granules of granular vinyl chloride resin were obtained. The sol dispersion characteristics of this granular vinyl chloride resin were determined. Example 2 100 g of diisononyl phthalate and a lipophilic nonionic surfactant in a 300 ml container [Reodol S manufactured by Kao Corporation]
P-L10, sorbitan monolaurate] 5 g,
Mix for 3 minutes on a high speed mixer. Thereafter, 50 g of water and 2 g of an emulsifier [Keio Co., Ltd., Leodol TW-L120, polyoxyethylene sorbitan monolaurate] were added and mixed for 10 minutes to obtain a water-in-oil type (W / O type) emulsion. . The aqueous dispersion of vinyl chloride resin for paste processing was passed through a screen having a wire mesh of 250 μm open beforehand, and water was added to the aqueous dispersion that had passed through to adjust the solid content to 35% by weight. Next, 11 kg of the prepared aqueous dispersion was put into a tank type mixing device having a diameter of 20 cm and an internal volume of 12 liters, and at the same time when stirring was started at 1100 rpm, the above water-in-oil type (W / O type) emulsion was introduced from the bottom of the mixing device. The injection was performed at a rate of 3.6 g / min for 35 minutes. Then, the mixture was further stirred and mixed at 1100 rpm for 90 minutes to obtain an aqueous dispersion of granular resin. This dispersion was vacuum filtered using a filter cloth having an air flow rate of 80 ml / sec · cm ² to separate the granular resin, and 6600 g of wet granular resin was obtained. When dried with a small fluid dryer, 3910 g
Granules of granular vinyl chloride resin were obtained. The sol dispersion characteristics of this granular vinyl chloride resin were determined.

COMPARATIVE EXAMPLE 1 An aqueous dispersion of a vinyl chloride resin for paste processing was passed through a screen having a mesh of 250 μm in advance, and water was added to the aqueous dispersion that had passed through to obtain a solid content of 35.
Adjusted to wt%. Next, 11 kg of the prepared aqueous dispersion was put into a tank type mixing device having a diameter of 20 cm and an internal volume of 12 liters,
At the same time when stirring was started at 1100 rpm, diisononyl phthalate was mixed from the bottom of the mixing device at a rate of 3.5 g / min.
Infused for 3 minutes. Then, the mixture was further stirred and mixed at 1100 rpm for 90 minutes to obtain an aqueous dispersion of granular resin. The dispersion wet granulation resin 6370g were separated vacuum filtered granular resin was obtained with an aeration rate of 80ml / sec · cm ² slag fabric. When this was dried with a small fluid dryer, 3950 g of granular vinyl chloride resin was obtained.
The sol dispersion characteristics of this granular vinyl chloride resin were determined. Comparative Example 2 An aqueous dispersion of a vinyl chloride resin for paste processing was passed through a screen previously covered with a wire mesh having an opening of 250 μ,
Water was added to the passed aqueous dispersion to adjust the solid content to 35% by weight. Next, prepare 11 kg of the aqueous dispersion to have a diameter of 2
Put it in a tank type mixing device of 0 cm and an internal capacity of 12 liters, and
At the same time when stirring was started at 00 rpm, diisononyl phthalate was injected from the bottom of the mixing device at a rate of 2.4 g / min for 33 minutes. After that, the mixture is further stirred and mixed at 1100 rpm.
After continuing for 0 minutes, a creamy aqueous dispersion was obtained. This dispersion was vacuum filtered using a filter cloth having an air flow rate of 80 cc / sec · cm ² to try to separate the resin, but the filter cloth was clogged and could not be separated. Table 1 shows the amount of organic liquid, solid-liquid separation state, NF value and vinyl chloride resin recovery rate used in Examples and Comparative Examples.

[0017]

[Table 1]

In Examples 1 and 2, the solid-liquid separation was good even when the amount of the organic liquid used was 2.1 parts by weight based on 100 parts by weight of the vinyl chloride resin in the aqueous dispersion. On the other hand, in Comparative Example 2, even when the amount of the organic liquid used was the same 2.1 parts by weight based on 100 parts by weight of the vinyl chloride resin in the aqueous dispersion, the aqueous dispersion was creamy and solid-liquid. Did not separate. From this result, it is understood that the vinyl chloride resin in the aqueous dispersion can be solid-liquid separated with a small amount of the organic liquid by using the water-in-oil type (W / O type) emulsion of the organic liquid. When using the organic liquid alone, 3.0 parts by weight of the organic liquid per 100 parts by weight of the vinyl chloride resin is required for solid-liquid separation as seen in Comparative Example 1, and still, As can be seen from the NF value, the dispersion characteristics of the sol were slightly inferior.

[0019]

EFFECT OF THE INVENTION It is necessary to obtain vinyl chloride resin particles as an aggregate by adding an organic liquid as a water-in-oil type (W / O type) emulsion to an aqueous dispersion of a vinyl chloride resin for paste processing. It becomes possible to reduce the amount of the organic liquid, and the dispersion state of the vinyl chloride resin in the plastisol becomes good.

Claims (1)

[Claims] 1. A vinyl chloride resin as an aggregate is added to an aqueous dispersion of a vinyl chloride resin for paste processing by adding an organic liquid that is hardly soluble in water and does not dissolve or swell the vinyl chloride resin from an aqueous phase. A method for producing a vinyl chloride resin for paste processing, wherein the organic liquid is a water-in-oil type (W / O type) emulsion in the method of separating and collecting.