WO1998046654A1

WO1998046654A1 - Vinyl chloride resin for paste processing, processes for producing the same, and plastisol containing the vinyl chloride resin

Info

Publication number: WO1998046654A1
Application number: PCT/JP1998/001656
Authority: WO
Inventors: Tomoyuki Kose; Takeshi Sumino; Soukichi Takashima; Taizou Yokoyama
Original assignee: Shin Dai-Ichi Vinyl Corporation
Priority date: 1997-04-11
Filing date: 1998-04-10
Publication date: 1998-10-22
Also published as: JP3973234B2

Abstract

A vinyl chloride resin for paste processing which, when analyzed by the laser diffraction method, has a specific continuous wide distribution ranging at least from 0.2 to 6 νm and having an average particle diameter of 1.3 to 4.0 νm, and which, when mixed with 45 parts by weight of di-2-ethylhexyl phthalate per 100 parts by weight of the resin, gives a paste having a Severs extrusion rate of 3 g/100 sec or higher; three processes for producing the vinyl chloride resin by fine suspension polymerization; and a plastisol containing the vinyl chloride resin for paste processing. The vinyl chloride resin, even when containing a relatively small amount of a plasticizer, can give a plastisol which has a low viscosity under high-shear conditions. The processes are effective in extremely efficiently producing the vinyl chloride resin.

Description

Vinyl chloride resin for paste processing, method for producing the same, and plastisol using the vinyl chloride resin

The present invention relates to a vinyl chloride resin for paste processing, a method for producing the same, and a plastisol using the vinyl chloride resin. More specifically, the present invention relates to a vinyl chloride resin for paste processing having a specific particle size distribution that gives a low-viscosity plastisol at a high shear rate even if the content of a plasticizer is relatively small. The present invention relates to a method for efficiently producing a suspension by fine suspension polymerization, and a polyvinyl chloride resin plastisol containing the above-mentioned vinyl chloride resin for paste processing and having a low viscosity at both a high shear rate and a low shear rate. is there. Background art

Conventionally, when paste processing vinyl chloride resin, the vinyl chloride resin manufactured for paste processing is homogenized together with plasticizers and, if necessary, compounding agents such as stabilizers, pigments, and fillers. Into a liquid plastisol, the liquid plastisol is molded by means such as casting, coating, and dipping, and then heated and melted to obtain a molded product.

Such paste processing occupies a major position in the heterogeneous dispersion processing of polymers, and plastisol has a wide range of compounding ranges and processing methods, and a wide variety from soft to hard. Since it is possible to obtain molded articles of various kinds, the application fields are wide, and in recent years, the demand thereof has been increasing worldwide.

Since the flow characteristics of plastisol have a very important effect on the moldability of paste processing, much effort and efforts have been made to improve the flow characteristics.

In general, vinyl chloride resin particles for paste processing have many primary particles and primary particles.

-1- Several aggregated particles are mixed. That is, it is a mixture of spherical primary particles having an average particle diameter of about 0.7 to 1. and secondary particles having a particle diameter of about several tens of meters, which are aggregates thereof. At the time of paste processing, such a resin particle is first mixed and dispersed in a plasticizer together with a heat stabilizer, a filler, a pigment and other compounding agents to prepare a plastisol.

The primary particles of conventional vinyl chloride resin for paste processing are usually spherical particles with an average particle diameter of about 0.7 to 1.3 zm.The smaller the particle diameter, the more the suspended particles in the plastisol will settle. Stable, low specific surface area when the particle shape is spherical, plasticizer adsorbed on the particle surface is immobilized and does not contribute to the fluidity of the plastisol. Particles that can be produced industrially stably also have a mean particle size of about 0.7 to 1.3 m.

In the vinyl chloride resin for paste processing, the ratio between the primary particles and the aggregates is usually arbitrary, but the aggregation strength of the aggregates is such that most of the aggregates are loosened during the kneading operation during plastisol preparation. There must be. In a plastisol, resin particles must basically be suspended as primary particles, but aggregates exist as long as they do not significantly affect the fluidity of the sol or the quality of molded products. Is also good. Depending on the purpose of molding, plastisol can be molded at a low shear rate of 0 to 10 Osec— ^{1 such} as cast molding, slush molding, and rotary molding. ~1, 0 0 O sec- ¹ of the coating is Ru Supuretsu de coated molded under high shear rate, or various end by a variety of processing methods, such as screen coating molding used in the middle under the shear rate of both Molded into products.

By the way, the plasticizer is not only a dispersion medium but also a factor that determines the flexibility of the final product.Therefore, even if an attempt is made to increase the amount of the plasticizer to make the plastisol have a low viscosity suitable for the intended processing method, the molded product will be soft. In some cases, it is not possible to increase the amount of plasticizer because it is too large.

In recent years, there has been an increasing demand for spread coating under high shear rates such as wallpaper, flooring or vinyl chloride resin coated steel sheet. In such applications, the touch of the product is often required to be dry touch, that is, to have a soft touch, but the plastisol plasticizer is reduced to give a dry touch feeling. If it is measured, there is a problem that molding processing becomes difficult.

As a method of lowering the viscosity of plastisol without increasing the amount of plasticizer, 20 to 40% by weight of a vinyl chloride resin for paste processing is prepared by suspension polymerization with a diameter of about 25 to 70 m. A method of substituting with a resin for blending is often employed. However, this method can be applied to applications such as slush molding and rotational molding where the surface of the molded product comes into contact with the mold and finishes.However, in the case of spread coating, the coating thickness is small. It is often as thin as several tens of meters / m, and in such a case, there is a problem that the resin for blending is projected or streaked on the surface of the coating film, impairing the appearance, and is difficult to apply. In addition, inconveniences such as a decrease in the transparency of the molded article and a loss of surface smoothness are likely to occur.

As another measure for reducing the viscosity of plastisol, a method of increasing the particle size of the vinyl chloride resin for paste processing can be considered. As such a method, for example, there has been proposed a method in which the operating pressure of a homogenizer is homogenized at a pressure of 5 to 50 kgZcni ² lower than a commonly used pressure in a fine suspension polymerization method (Japanese Patent Laid-Open No. 2-1). No. 940707 publication). However, this method uses an emulsifier to stabilize the emulsified droplets.

In addition to (anionic surfactant), a dispersant such as polyvinyl alcohol or a water-soluble cellulose derivative is used in combination, so that the obtained resin particles have high hygroscopicity, and the molding obtained by using this is It is difficult to put the product into practical use because it foams when heated and whitens due to moisture. Disclosure of the invention

In view of such circumstances, a first object of the present invention is to provide a plastisol having a low viscosity at a high shear rate even if the content of a plasticizer is relatively small, which is particularly required in spread coating molding. The purpose of the present invention is to provide a vinyl chloride resin for paste processing.

Further, a second object of the present invention is to provide a method for efficiently producing the above-mentioned vinyl chloride resin for paste processing by fine suspension polymerization.

Further, a third object of the present invention is to use the above-mentioned vinyl chloride resin for paste processing. It is an object of the present invention to provide a vinyl chloride resin plastisol having a lower viscosity even at a low shear rate under a high shear rate and a low shear rate.

The present inventors have conducted intensive studies to achieve the above object, and as a result, having a specific particle size range and particle size distribution, and a vinyl chloride resin having specific flow characteristics, It has been found that the two objectives are achieved.

In addition, if the emulsion obtained by emulsifying at least half of the emulsifying aid used in advance in the presence of an aqueous medium with at least half of the emulsifying agent used has an oil-soluble radical initiator, After pre-mixing the monomer with the emulsifier and / or emulsifier, and pre-mixing, homogenizing and then subjecting to fine suspension polymerization, the vinyl chloride resin for paste processing having the above properties is obtained. And found that the second objective was achieved.

Furthermore, they have found that the first and second objects can also be achieved by the following methods. That is, the following is known as a polymerization mechanism in emulsion polymerization of a vinyl chloride-based monomer performed in the presence of an emulsifier and a water-soluble radical initiator in an aqueous medium. In the reaction system in the emulsion polymerization, the monomer is dissolved in the emulsion micelle (dissolved phase) and the surrounding monomer oil droplets adsorbing the emulsifier molecules are present. ) And occurs on the surface of the monomer oil droplets, but the polymerization speed in the micelles is much higher than the polymerization speed on the surface of the monomer oil droplets, so that the polymerization proceeds substantially in the micelles. When the amount of the monomer in the micelle decreases, the monomer is replenished from the monomer oil droplets by diffusion, and the polymerization proceeds further. When the polymer particles become large to a certain extent, the micelle disperses by adsorbing the emulsifier. Become a phase.

The present inventors have focused on the polymerization mechanism in such emulsion polymerization, and in fine suspension polymerization, if a difference in the concentration of the radical initiator is provided between monomer droplets, droplets having a high radical initiator concentration will However, since the polymerization rate is higher than that of the low-concentration droplets, the monomer is consumed quickly and becomes monomer-starved. Was supplied, and the polymerization would proceed further, producing a large particle polymer.

Therefore, the present inventors have found that in the production of vinyl chloride resin by fine suspension polymerization, Intensive research has been conducted on providing a radical initiator concentration difference between monomer droplets, and at least 20% by weight of the oil-soluble radical initiator to be used is added in the latter half of premixing before homogenization. By using the oil-soluble radical initiator in an emulsified state in the pre-mixing, a difference in the concentration of the radical initiator occurs between the monomer droplets, and the chloride for paste processing having the above-mentioned property having a large particle diameter is obtained. A vinyl resin was obtained, and it was found that the first and second objects were achieved.

Next, a plastisol obtained by adding a plasticizer at a predetermined ratio to a vinyl chloride resin mixture comprising a specific ratio of the vinyl chloride resin for pasting and a vinyl chloride resin having a small particle size is used. It has been found that the three objectives are achieved.

The present invention has been completed based on such findings.

That is, the present invention

(1) A vinyl chloride resin for paste processing, in which the particle size measured by laser diffraction is continuously and widely distributed in the range of at least 0.2 to 6 m, and has two maximum values in frequency. The particle size giving the maximum value of the group of small particles is 0.2 to 0.5 / m, the particle size giving the maximum value of the group of large particles is 1.5 to 4.0 // m, and The average particle size of the whole is 1.3 to 4.0 zm, the particles having an average particle size of 0.5 / m or less have a particle size distribution of 5 to 40% by weight, and the resin has a weight of 100 parts by weight. A paste obtained from a mixture of styrene and G-2-ethylhexyl phthalate (45 parts by weight) with a saver release of 3 g / 100 seconds or more. Resin,

(2) An aqueous medium, an emulsifier, an emulsifier, an oil-soluble radical initiator, and vinyl chloride or an unsaturated monomer copolymerizable therewith are charged and premixed in a container equipped with a stirrer. This premixed solution is homogenized in a homogenizer and transferred to a polymerization vessel to perform fine suspension polymerization. After processing to prepare an emulsion, the oil-soluble radical initiator and the remaining emulsifier and / or emulsifier if any, and vinyl chloride or unsaturated chloride copolymerizable with vinyl chloride The method for producing a vinyl chloride resin for paste processing according to the above item (1), which comprises adding a monomer and preliminarily mixing (hereinafter referred to as the production method [1]); (3) An aqueous medium, an emulsifier, an oil-soluble radical initiator, vinyl chloride or vinyl chloride and an unsaturated monomer copolymerizable therewith are charged into a vessel equipped with a stirrer, and preliminarily mixed. Is homogenized in a homogenizer and transferred to a polymerization vessel to perform fine suspension polymerization, characterized in that at least 20% by weight of the oil-soluble radical initiator used is added in the latter half of the premixing time. Method (1) for producing a vinyl chloride resin for paste processing (hereinafter referred to as production method [2]),

(4) An aqueous medium, an emulsifier, an oil-soluble radical initiator, vinyl chloride or vinyl chloride and an unsaturated monomer copolymerizable therewith are charged into a vessel equipped with a stirrer, and preliminarily mixed. Wherein the oil-soluble radical initiator is added in an emulsified state and is preliminarily mixed by a homogenizing treatment with a homogenizer and transferring to a polymerization vessel to carry out fine suspension polymerization. ), The method for producing a vinyl chloride resin for finishing processing (hereinafter referred to as the production method [3]),

as well as

(5) A vinyl chloride resin comprising 60 to 100% by weight of the vinyl chloride resin for paste processing described in (1) and 0 to 40% by weight of a vinyl chloride resin having an average particle size of 0.1 to 0.4 / m. A vinyl chloride resin plastisol characterized by containing 100 parts by weight of a mixture and 20 to 80 parts by weight of a plasticizer,

Is provided. BEST MODE FOR CARRYING OUT THE INVENTION

The vinyl chloride resin for paste processing of the present invention is required to have the following properties.

First, the particle size determined by the laser diffraction method is continuously and widely distributed in the range of at least 0.2 to 6 / m, has two maximum values in frequency, and gives the maximum value of the group of small particles. Is 0.2 to 0.5 m, the particle size giving the maximum value of the group of large particles is 1.5 to 4.0 m, and the overall average particle size is 1.3 to 4.0 / 111, preferably 1.3 to 3.0 m, It is necessary that the particles having an average particle size of 0.5 zm or less have a particle size distribution in the range of 5 to 40% by weight, preferably 10 to 35% by weight. Particle size distribution If the average particle size is out of the range specified above, a vinyl chloride resin having desired properties cannot be obtained.

The particle size distribution and the average particle size in the present invention are measured by a laser diffraction method described below. That is, after preparing a 0.5% by weight aqueous dispersion of a vinyl chloride resin, the dispersion was subjected to a laser diffraction / scattering type particle size distribution analyzer “LA-910” manufactured by HORIBA, Ltd. to obtain a particle size distribution. From the frequency particle size distribution curve.

A particle size d50 corresponding to 0% by weight is determined, and the average particle size of the primary particles is determined.

Next, in the vinyl chloride resin for paste processing of the present invention, 100 parts by weight of the resin and 45 parts by weight of di-2-ethylhexyl phthalate are mixed, and the amount of the outflow of the paste obtained by mixing the paste is 45 parts by weight. It must be at least 3 g / 100 seconds. If the amount of the outflow of the soapers is less than 3 g / 100 seconds, the viscosity of the plastisol at a high shear rate is low, the workability in spread coating molding and the like is poor, and the object of the present invention is achieved. I can't. The amount of this outflow from the savers is preferably 3 g Z 100 seconds or more, and particularly preferably 10 g / 100 seconds or more.

In addition, the savers outflow amount of the paste is a value measured by the following measurement method. That is, in an atmosphere of 23 ° C and a relative humidity of 60%, 100 parts by weight of a vinyl chloride resin for paste processing and 45 parts by weight of di-2-ethylhexyl phthalate were weighed with a mortar. The plastisol obtained by kneading was degassed in vacuo and allowed to stand at 23 ° C for 1 hour. Then, using a Severs flowmeter (Caster, Mode 1A—100), the length was 5 mm. Flow out from a nozzle with a diameter of 1.56 and a pressure of 95 psi, and measure the sol flow rate (g) for 100 seconds. The higher the outflow, the lower the sol viscosity at high shear rates.

The vinyl chloride resin for paste processing according to the present invention having such properties has a low viscosity at a high shear rate even if the plasticizer content is relatively low, which is particularly required for thread coating molding. Plastisols can be provided.

The vinyl chloride resin for paste processing of the present invention having such excellent properties can be produced extremely efficiently by the production method of the present invention described below. Next, a method for producing the vinyl chloride resin for paste processing of the present invention will be described. In the method of the present invention, a vinyl chloride resin for paste processing is produced by fine suspension polymerization in an aqueous medium. In this case, as a raw material monomer, vinyl chloride alone, or a mixture of vinyl chloride alone and an unsaturated monomer copolymerizable therewith is used. Here, unsaturated monomers copolymerizable with vinyl chloride include, for example, acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, gay cinnamate, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride. Unsaturated monocarboxylic acids, such as unsaturated dicarboxylic acids and anhydrides thereof; monoalkyl esters of fumaric acid, monoalkyl esters of itaconic acid, etc .; monoalkyl esters of unsaturated dicarboxylic acids; methyl or methacrylic acid or methacrylic acid Unsaturated monocarboxylic esters such as propyl, butyl, octyl, cyclohexyl and benzyl esters; dimethyl, dimethyl, getyl, dipropyl, dibutyl, maleic acid and fumaric acid, octyl, dicyclohexyl, dibenzyl ester, etc. Unsaturated dicarboxylic acid diesters; Vinyl ethers such as tyl vinyl ether, ethyl vinyl ether and propyl vinyl ether; olefins such as ethylene, propylene, butene 1-1 and pentene-1; aromatic monovinyl compounds such as styrene and α-methylstyrene; acrylonitrile Vinyl cyanide compounds such as methacrylonitrile; unsaturated amide compounds such as acrylamide and methacrylamide; carboxylic acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl propyl acrylate, and vinyl propyl acrylate; Is vinylidene chloride. These copolymerizable monomers may be used alone or in combination of two or more. When a mixture of vinyl chloride and the above copolymerizable unsaturated monomer is used as a raw material monomer, the content of vinyl chloride in the monomer mixture should be 50% by weight or more. Preferably, it is 75% by weight or more.

In the production method of the present invention, there are three embodiments. In the production method [1], an emulsifier, an emulsification auxiliary agent, and an oil-soluble radical initiator are used together with the raw material monomers as essential components for polymerization. On the other hand, in the production methods [2] and [3], an emulsifier and an oil-soluble radical initiator are used together with the raw material monomers as essential components, and an emulsification aid is used if desired. In the production methods [1], [2] and [3] of the present invention, the emulsifier used as an essential component is not particularly limited, and the emulsifier conventionally used for producing a vinyl chloride resin by fine suspension polymerization is conventionally used. Any of the listed items can be selected and used. Examples of the emulsifier include alkyl sulfates such as sodium lauryl sulfate and sodium myristyl sulfate; alkyl aryl sulfonates such as sodium dodecyl benzene sulfonate and potassium dodecyl benzene sulfonate; sodium octyl sulfosuccinate; Sulfosuccinates such as dihexyl sodium sulfosuccinate; Fatty acid salts such as ammonium laurate, half-hardened tallow fatty acid potassium, potassium stearate; Polyoxetylene alkyl sulfate; Polyoxoche Tylene alkylaryl sulfates; alkyl ether phosphates; anionic surfactants such as alkane sulfonates; sorbitan monoolate, polyoxyethylene sol Sorbitan esters such as bitan monostearate; polyoxyethylene alkyl ethers; polyoxyethylene alkylphenylenes; nonionic surfactants such as polyoxyethylene alkyl esters; Cationic surfactants such as dinium chloride and cetyltrimethylammonium bromide may be mentioned.These may be used alone or in combination of two or more. The amount used can be appropriately selected within the range of 0.3 to 2.5 parts by weight, preferably 0.5 to 2.0 parts by weight, per 100 parts by weight of the monomer usually used.

In the production method [1], as an essential component, or in the production methods [2] and [3], as a desired component, there is no particular limitation on an emulsifying auxiliary used in combination with the emulsifier. Is appropriately selected from those commonly used in the production of glycerol by fine suspension polymerization, such as higher alcohols, higher fatty acids, lipophilic nonionic surfactants, chlorinated paraffins, phthalic esters, and fatty acid esters. Can be used. Here, as the higher alcohol, for example, an alcohol having an alkyl group having 8 to 24 carbon atoms is preferably exemplified, and as the higher fatty acid, for example, a fatty acid having an alkyl group having 10 to 20 carbon atoms is preferably exemplified. Can be As the lipophilic nonionic surfactant, for example, a nonionic surfactant in which ^ 1 and 8 are 1 to 10 is preferable, and specific examples thereof include polyoxyethylene lauryl ether (5 to 10) and polyoxyethylene. Ethylene nonylphenyl ether (5 to: L0), sorbitan monopalmitate (6.7), sorbitan monolaurate (8.6), sorbitan monostearate (4.7), sorbitan tristearate (2.1), di (glycerin) Volatile monostearate (7.6) and di (glycerin) borate sesquistearate (5.7). The figures in parentheses are HL Bi.

One of these emulsifiers may be used alone, or two or more thereof may be used in combination.The amount of the emulsifier is usually 0.1 to 2.5 parts by weight, preferably 0.3 to 100 parts by weight of the monomer used. It can be suitably selected in the range of ~ 1.5 parts by weight.

On the other hand, in the production methods [1], [2] and [3], the oil-soluble radisol initiator used as an essential component includes, for example, dibenzoyl beloxide, di-1,3,5,5-trimethyl. Diacylperoxides such as xanylperoxide and dilauroylperoxide; diisopropylperoxydicarbonate, disec-butylperoxydicarbonate, di-2-ethylhexylperoxy Peroxydicarbonates such as dicarbonate; Peroxyesters such as t-butylperoxypiperate and t-butylperoxyneodecanoate; or acetylcyclohexylsulfonylperoxide And organic peroxides such as disuccinic acid peroxide; and 2,2'-azobisisobutyronitrile and 2, 2'-azobis An azo compound such as 2-methylbutyronitrile and 2,2′-azobisdimethyl phenol nitronitrile can be used. One or more of these catalysts can be used in combination, and the amount used is appropriately selected depending on the type and amount of the monomer, the charging method, and the like. The weight can be selected in the range of 0.001 to 5.0 parts by weight.

Next, embodiments of the present invention will be described.

First, in the production method [1], a pre-mixing step, a homogenization treatment step, and a fine suspension polymerization step are sequentially performed to produce a vinyl chloride resin for paste processing. The premixing step is a step of adding an emulsifier, an emulsification aid, an oil-soluble radical initiator, vinyl chloride or vinyl chloride and an unsaturated monomer copolymerizable therewith to an aqueous medium and mixing.

In this production method [1], in the pre-mixing step, an emulsification treatment was performed by emulsifying at least half of the emulsifier used and at least half of the emulsifier used in the presence of an aqueous medium in advance. After that, the above components are added and premixed. The preparation and preliminary mixing of the above-mentioned emulsion can be performed, for example, by the following procedure.

First, an aqueous medium is added to a container equipped with a stirrer, and then half or more, preferably the entire amount of the emulsifying aid to be used is charged, and the liquid temperature is maintained at or above its melting point so that the emulsifying aid becomes liquid. While stirring. Next, while stirring, an emulsifier is added by adding at least half, preferably all, of the emulsifier to be used for emulsification to prepare an emulsion. Next, when the emulsification treatment was performed in a container different from the premixer, the obtained emulsion was transferred to the premixer and then applied to the emulsion or the emulsification treatment was performed in the premixer. In this case, add the oil-soluble radical initiator and, if there is a residual amount, the remaining emulsifier and / or emulsifying aid to the obtained emulsion and continue stirring. Alternatively, add vinyl chloride and an unsaturated monomer copolymerizable therewith, and start premixing.

The premixing time is preferably 3 to 40 minutes under stirring with a net stirring power per unit volume of 0.3 to ³ kWZm3. If the pre-mixing time is less than 3 minutes, the pre-mixing is insufficient, the droplets are unstable even after homogenization, many agglomerates and scales are generated, and in severe cases, they may solidify in the polymerization vessel. . On the other hand, if the premixing time exceeds 40 minutes, the effect of the present invention may not be exhibited due to the premixing being performed more than enough. In view of the stability and effect of the droplets, a particularly preferred premixing time is 5 to 30 minutes under stirring at a net stirring power of 0.3 to ³ kWZm3 per unit volume.

In the production method [1] of the present invention, in the premixing step, an emulsion obtained by emulsifying an emulsifier with an emulsifier is used in the premixing step as described above. It takes a long time for By setting the time to about 40 minutes, the heterogeneous premixed liquid will be homogenized. As a result, there is a difference in the concentration of the emulsifying aid between the emulsion monomer droplets, which results in a difference in the protective strength between the emulsion monomer droplets.As the frequency of aggregation and coalescence of the droplets increases, the particle size increases. It is presumed that many polymers are produced.

The above-mentioned required net stirring power per unit is a value obtained by dividing the stirring power excluding the rotational driving load of the transmission, the speed reducer and the stirrer by the internal volume from the total stirring power, and It can be calculated by the following equation.

PNP · p · n ³ · d

P

V · V

here,

: Power required for stirring per unit volume (kWZm ³ )

P: stirring power (kW)

V: liquid volume (m ³ )

N P: Number of power, fixed value of stirring blade, empirical value is used.

Example, Fowler wing: 1.5,

Max blend wing · Full zone wing: 2.5,

Loop wings' anchor wings: 1.0

P: Liquid density (kgZm ³ )

n: Number of rotations (1 / sec)

d: stirring blade diameter (m)

: Gravity conversion coefficient [(kg'm) Z (kg'sec ² )]

As another method of obtaining the required net stirring power per unit internal volume, there is a method using an ammeter of an electric motor of a container stirrer. Turn the stirrer in advance when the container is empty, know the rotational drive load of the transmission or reduction gear and the stirrer itself with an ammeter, and apply this to the value obtained by crossing I from the ammeter reading during premixing. It is determined by multiplying by the voltage and dividing by the liquid volume.

The pre-mixed liquid thus prepared is homogenized by a homogenizer and then transferred to a polymerization vessel to perform fine suspension polymerization. Regarding this homogenization treatment and polymerization, I will explain later.

Next, in the production method [2], a container equipped with a stirrer is first placed in an aqueous medium, an emulsifying agent | J, an emulsifying auxiliary used as required, and vinyl chloride or an unsaturated monomer copolymerizable therewith. Charge the body or together with it, pre-mix less than 80% by weight of the oil-soluble radical initiator used. At this time, in the latter half of the pre-mixing time, the remaining oil-soluble radical initiator, that is, 20% by weight or more of the oil-soluble radical initiator to be used is added to the mixed solution.

If the amount of the oil-soluble radical initiator added thereafter is less than 20% by weight of the amount used, a sufficient difference in the concentration of the radical initiator between monomer droplets is not provided, and the object of the present invention is achieved. I can't. In order to provide a sufficient radical initiator concentration difference between the monomer droplets, premixing preferably 50% by weight or more, more preferably 90% by weight or more of the oil-soluble radical initiator to be used. Advantageously, the addition takes place 50 to 75% of the total premixing time since the start.

The pre-mixing time depends on the type of the stirrer, but is generally preferably in the range of 3 to 60 minutes under the stirring of 0.3 to ³ kWZm3 in the net power required per unit volume. In particular, a range of 5 to 40 minutes is preferable.

In this way, a premix liquid having a sufficient radical initiator concentration difference between monomer droplets is prepared. This premixed liquid is homogenized by a homogenizer in the same manner as in the above production method [1], and then transferred to a polymerization vessel to perform fine suspension polymerization. This homogenization treatment and polymerization will be described later.

On the other hand, in the production method [3], a container equipped with a stirrer first contains an aqueous medium, an emulsifier, an optional emulsifier, an oil-soluble radical initiator in an emulsified state, vinyl chloride or vinyl chloride and A copolymerizable unsaturated monomer is charged and premixed.

In this production method [3], an emulsified oil-soluble radical initiator used for premixing is used. The oil-soluble radical initiator in the emulsified state is, for example, a mixture of 100 parts by weight of a radical initiator, 50 to 400 parts by weight of water, and 0.5 to 2 parts by weight of an emulsifier, and high-speed stirring and dispersing. , With a stirring homogenizer, etc. It can be prepared by homogenization. As the emulsifier to be used at this time, the same emulsifiers as those exemplified above as the emulsifier in the fine suspension polymerization can be exemplified. The oil-soluble radical initiator can be used as a solution dissolved in an organic liquid at a concentration of about 10 to 80% by weight. Particularly, those having high activity are advantageous in terms of handleability when used as such a solution. Examples of the organic liquid include n-hexane, mineral spirit, toluene, and a plasticizer such as dioctyl phthalate.

The oil-soluble radical initiator in an emulsified state thus prepared takes a long time to dissolve in the monomer due to the repulsive force of the ions therein, and is thus obtained by adding this. It is considered that the premixed liquid has a sufficient radical initiator concentration difference between the monomer droplets.

This premixed liquid is homogenized by a homogenizer in the same manner as in the production methods [1] and [2], and then transferred to a polymerization vessel to perform fine suspension polymerization.

Next, the homogenization treatment in the production methods [1], [2] and [3] of the present invention is performed using a homogenizer (homogenizer). By this homogenization treatment, the particle size of the oil droplets is adjusted. Examples of the homogenizer include a colloid mill, a vibration stirrer, a two-stage high-pressure pump, a high-pressure jet from a nozzle and an orifice, and ultrasonic stirring. In addition, the adjustment of the oil droplet size is affected by the control of the shearing force during the homogenization treatment, the stirring conditions during the polymerization, the type of reactor, the amount of emulsifier and emulsifier, etc. Appropriate conditions can be selected by preliminary experiments.

Next, the liquid homogenized in this manner is sent to a polymerization vessel, and the temperature is increased while stirring slowly, and polymerization is usually performed at a temperature in the range of 30 to 80 ° C.

The shape of the polymerization vessel used in the production methods [1], [2] and [3] of the present invention is not particularly limited. For example, a polymerization vessel having an outer jacket or an inner jacket can be used. It is also possible to install a reflux condenser. Among these, a polymerization reactor having an internal jacket has a small heat transfer loss, and can accurately measure the calorific value in the polymerization reactor and accurately determine the polymerization rate. it can. There are no particular restrictions on the method of stirring in the polymerization vessel. Stepped wings, paddle wings, multi-stage paddle wings, blue margin wings, anchor wings, loop wings, max-blend wings, full zone wings, etc. can be used. In the production methods [1], [2] and [3] of the present invention, the monomer polymerization conversion per hour is leveled and the reaction heat removal is reduced as long as the object of the present invention is not impaired. If necessary, a polymerization inhibitor or a polymerization retarder can be appropriately added in the course of the polymerization reaction for the purpose of making the load uniform. The polymerization inhibitor and the polymerization retarder are not particularly limited, and may be appropriately selected from those conventionally used in the production of vinyl chloride resins. Examples of polymerization inhibitors include phenolic compounds such as hydroquinone and p-t-butylcatechol; N, N-getylhydroxylaminate, N-nitrosophenylhydroxylamineammonium salt Peroxyl); and organic thio compounds such as dithiobenzoyl disulfide and tetraethylthiuram disulfide. These may be used alone or in combination of two or more.

On the other hand, examples of the polymerization retarder include cycloalkene compounds having 5 to 8 carbon atoms such as cyclopentene, cyclohexene, and cyclopentene, and these may be used alone or in combination of two or more. May be used.

If desired, known additives such as a chain transfer agent, a crosslinking agent, a scale inhibitor, and an antifoaming agent can be added to the polymerization system.

The polymerization pressure is usually 3.4 to; L 3.7 kgZcra ² G, preferably 5.2 to 10. 0 kgZcra ² G, and the polymerization time is determined by the type of raw material monomer and catalyst. It depends on various conditions such as the type and amount, the polymerization temperature, the polymerization pressure, and the desired degree of polymerization of the obtained polymer. Although it cannot be roughly determined, it is usually about 2 to 20 hours.

In the production methods [2] and [3], the polymerization method described above causes a difference in the concentration of the radical initiator between the monomer droplets. Therefore, a droplet having a high concentration of the radical initiator has a low concentration. Since the polymerization rate is faster than the droplets and the monomer is consumed faster and becomes starved, the monomer is supplied by diffusion from the droplet having a low radical initiator concentration, and the polymerization proceeds further. It is considered that a polymer having large particles can be obtained. Thus, in the production methods [1], [2] and [3], vinyl chloride is used. An aqueous dispersion of the base resin particles is obtained. After completion of the polymerization, the vinyl chloride resin is recovered as a powder by a commonly used known means such as spray drying. If necessary, the powder may be further pulverized to loosen the agglomeration generated during drying to obtain a powder mainly composed of primary particles.

According to such a production method of the present invention, the vinyl chloride resin for paste processing of the present invention having an average particle size in the range of 1.3 to 4.0 m and having the above-mentioned particle size distribution is extremely efficient. Well obtained.

In order to prepare a plastisol using the vinyl chloride resin for paste processing of the present invention, a method conventionally used in the preparation of a vinyl chloride resin plastisol can be employed. For example, plasticizer and various optional components used for paste processing vinyl chloride resin, specifically, heat stabilizer, filler, foaming agent, foaming accelerator, surfactant, viscosity modifier, adhesive Mixing properties imparting agents, coloring agents, diluents, UV absorbers, antioxidants, reinforcing agents, other resins, etc., using a planetary mixer, kneader, roll, crusher, etc. By sufficiently kneading the mixture, a plastisol can be prepared.

The plasticizer used for preparing this plastisol is not particularly limited, and those conventionally used as plasticizers for the vinyl chloride resin plastisol, for example, dimethyl phthalate, getyl phthalate, dibutyl phthalate, dibutyl phthalate (2) —Ethylhexyl) phthalate, di-n-octyl phthalate, diisobutyl phthalate, diheptyl phthalate, diphenyl phthalate, diisodecyl phthalate, ditridecyl phthalate, divinyl decyl phthalate, di (heptyl, nonyl, ゥ) Phthalic acid derivatives such as ndecyl) phthalate, benzyl phthalate, butyl benzyl phthalate, dinonyl phthalate, dicyclohexyl phthalate; dimethyl isophthalate, di (2-ethylhexyl) isophthalate, diisooctyl Isophthalic acid derivatives such as isophthalate; tetrahydrophthalic acid derivatives such as di- (2-ethylhexyl) tetrahydrophthalate, di-n-octyltetrahydrophthalate, diisodecyltetrahydrophthalate; di-n-butyl adipate, di- I (2-ethylhexyl) adipate, diisodecyl adipate, di Adipic acid derivatives such as isononyl adipate; Azelaic acid derivatives such as di (2-ethylhexyl) azelate, diisooctyl azelate, di-n-hexyl azelate; di-n-butyl sebacate, di Sebacic acid derivatives such as i- (2-ethylhexyl) sebacate; maleins such as di-n-butyl maleate, dimethyl maleate, getyl maleate, di- (2-ethylhexyl) maleate Acid derivatives; fumaric acid derivatives such as di-n-butyl fumarate and di- (2-ethylhexyl) fumarate; tri- (2-ethylhexyl) trimellitate, tri-n-octyl trimellitate, triisodecyl Trime reitate, triisooctyl trime reate, tri-n-hexyl trime reate, triisononyl trime Trimethyl citrate derivatives such as litolate; pyromethyl citrate derivatives such as tetra- (2-ethylhexyl) pyrromelate and tetra-n-octylbiromerate; triethyl citrate, tri-n-butyl citrate Citrate derivatives such as acetyl acetyl triethyl citrate and acetyl tri (2-ethylhexyl) citrate; monomethyl itaconate, monobutyl itaconate, dimethyl ether conjugate, getyl itaconate, dibutyl itaconate, dibutyl itaconate, Itaconic acid derivatives such as di- (2-ethylhexyl) itaconate; oleic acid derivatives such as butyl ester, glyceryl monooleate and diethylene glycol monooleate; methyl acetyl cinolenate, butyl acetyl Ricinolate, glyceryl mono lithi Ricinoleic acid derivatives such as oleate and diethylene glycol mono-ricinoleate; stearic acid derivatives such as n-butyl stearate, glycerin monostearate and diethylene glycol distearate; diethylene glycol monolaurate, diethylene glycol diperargonate, and pentaerythritol fatty acid ester Other fatty acid derivatives of: triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyshethyl phosphate, triphenyl phosphate, cresyl diphenyl Phosphate derivatives such as phosphate, tricresyl phosphate, trixylenyl phosphate, tris (chloroethyl) phosphate; diethylene glycol dibenzoate, zip Propylene glycol dibenzoate, triethylene glycol dibenzoate, Glycol derivatives such as ethylene glycol di (2-ethyl butyrate), triethylene glycol di (2-ethylhexanoate), dibutyl methylene bisthioglycolate; glycerol monoacetate, glycerol triacetate, glycerol Glycerin derivatives such as triptylate; epoxidized soybean oil, epoxybutyl stearate, epoxy-2-diethylhexylhexahydrophthalate, diisodecyl epoxyhexahydrophthalate, epoxytriglyceride, eptyl octyl oleate, Epoxy derivatives such as epoxidized decyl oleate; polyester plasticizers such as adipic acid-based polyester, sebacic acid-based polyester, and phthalic acid-based polyester; or partially hydrogenated terphenyl, adhesive properties Plasticizers, more di § Lil phthalate, but like acrylic monomers one or oligomers which polymerization plasticizers, it is preferable that the phthalate in these. One of these plasticizers may be used, or two or more of them may be used in combination. A plasticizer in which a high molecular compound such as rubber or resin is dissolved can also be used arbitrarily. The amount of the plasticizer is usually selected in the range of 40 to 250 parts by weight per 100 parts by weight of the vinyl chloride resin.

The plastisol prepared using the vinyl chloride resin for paste processing of the present invention has a low viscosity (because resin particles having a large particle size are used as compared with the conventional plastisol, and can be rubbed. It can be used as a material for flooring, wall covering, toys, automotive interior materials, painted steel plates, vibration damping steel plates, laminated glass, sealing materials, foams, etc. Can be used. In particular, since the viscosity becomes low at a high shear rate, the plastisol is advantageous when used for high-speed coating applications, for example, for wallpaper, canvas, and PVC steel sheets.

The present invention also provides a vinyl chloride resin comprising 60 to 100% by weight of the vinyl chloride resin for paste processing and 0 to 40% by weight of a vinyl chloride resin having an average particle size of 0.1 to 0.4. 100 parts by weight of a vinyl chloride resin mixture, preferably 70 to 95% by weight of the former resin and 5 to 30% by weight of the latter resin, and 20 to 250% by weight of a plasticizer Also provided is a plastisol containing 2 parts by weight, preferably 20 to 80 parts by weight. Here, the mixing of the two types of resins may be performed in a powder state, or the lamination after the polymerization is completed. It may be performed in the state of Tex.

Such a plastisol has a low viscosity under both a high shear rate and a low shear rate, and is excellent in processability.

Plastisol The molding method used under high shear rates, e.g. Naifuko computing Ya Roruko one computing like 1 0 0~1, 0 0 O sec- 1 of Supuretsu de coating molding to be coated under high shear rates In such molding, the outflow of savers is important as a viscosity characteristic, and the larger the outflow of soapers, the lower the sol viscosity.

Examples of the molding method in which plastisol is used at a low shear rate include, for example, mold molding performed at a low shear rate of 0 to 100 sec- ¹ such as cast molding, slush molding, and rotational molding, or There is a dipping application molding, etc. In such molding, B-type viscosity is important as a viscosity characteristic.

The plastisol of the present invention has a low viscosity in any of the above, and has excellent processability.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

In addition, each characteristic was evaluated according to the following method.

(1) Particle size distribution and average particle size of primary particles

After the polymerization, the latex is diluted with water, and a 0.5% by weight dispersion is prepared using an ultrasonic disperser. Then, the particle size distribution and the average particle size of the primary particles are determined according to the method described in the specification. The diameter was measured.

(2) Paste viscosity

It is obtained by kneading 100 parts by weight of a vinyl chloride resin for paste processing and 45 parts by weight of di-2-ethylhexyl phthalate in an atmosphere of 23 ° C and a relative humidity of 60% using a mortar. The plastisol was degassed in vacuo and allowed to stand at 23 ° C for 1 hour, and then measured with a Brookfield viscometer (BM type manufactured by Tokyo Keiki) at a rotor number of 4 and a rotation speed of 6 rpm. This shows the sol viscosity at low shear rates.

(3) Outflow of Saper's The plastisol obtained after standing at 23 ° C. for 1 hour obtained in the above (2) was measured for the amount of the outflow of Sweepers according to the method described in the specification text.

Reference example 1

A 10-liter stainless steel stirrer and a pressure-resistant reactor equipped with a jacket were charged with 167 parts by weight of deionized water, 0.2 parts by weight of stearic acid, 0.02 parts by weight of potassium persulfate, and sodium lauryl sulfate. 0.01 part by weight was charged, and nitrogen replacement and degassing under reduced pressure were repeated twice each. Thereafter, 100 parts by weight of vinyl chloride was charged, the temperature was raised while stirring, and emulsion polymerization was started at 60 ° C. During a period of polymerization conversion of 5 to 85% by weight, a total of 16 parts by weight of a 3% by weight aqueous solution of sodium lauryl sulfate was injected at a constant rate.

Cool when the polymerization conversion rate reaches 90% by weight, remove unreacted monomers, and add 4 parts by weight of a 5% by weight aqueous solution of sodium lauryl sulfate to stabilize with almost no scale. Thus, an aqueous dispersion of polymer particles was obtained.

The particle size distribution of the primary particles have a peak at 0. 3 / m, are distributed to 0. 1 ~ 0. 5 / m, also d ₅₀ was 0. 3〃M.

Next, the above-mentioned aqueous dispersion of polymer particles was dried with a spray dryer, and then pulverized with a hammer mill to obtain a small-particle vinyl chloride resin.

Comparative Example 1

A 10-liter stainless steel stirrer and a pressure-resistant reactor equipped with a jacket were charged with 120 parts by weight of deionized water, 0.8 part by weight of sodium dodecylbenzenesulfonate, and radial alcohol (melting point: 25 ° C 0.5 part by weight, 0.07 parts by weight of a 50% by weight n-hexane solution of di-isopropylperoxydicarbonate was charged, and the replacement with nitrogen and the degassing under reduced pressure were repeated twice. Thereafter, 100 parts by weight of vinyl chloride were charged, and the mixture was stirred at 28 ° C. for 30 minutes with stirring at a required power of 0.95 kWZm ³ for premixing.

After homogenizing this pre-mixed liquid with a two-stage high-pressure homogenizer, it is transferred to another 10 liter degassed pressure-resistant reactor similar to the above, and stirred under mild conditions for the purpose of heat transfer. While the temperature was raised, fine suspension polymerization was performed at 47 ° C.

When the polymerization conversion reaches 90% by weight, cool to remove unreacted monomers. As a result, a stable aqueous dispersion of polymer particles was obtained with almost no scale. Next, the polymer particle aqueous dispersion was dried with a spray drier and then pulverized with a hammer mill to obtain a vinyl chloride resin (A) for paste processing.

Table 1 shows the evaluation results of the vinyl chloride resin (A) and the evaluation results of a mixture of 85 parts by weight of the resin (A) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Example 1

Charge 120 parts by weight of water into the pre-mixer, stir at 28 ° C, and mix with a mixture of 10 to 18 carbon atoms with lauryl alcohol as the main component (melting point: 25 ° C) 0.5% by weight Then, 0.8 parts by weight of sodium dodecylbenzenesulfonate was added to prepare an emulsion. Next, 0.07 parts by weight of a 50% by weight n-hexane solution of diisopropylisopropyloxycarbonate was added thereto, and nitrogen replacement and reduced pressure degassing were repeated twice each. Subsequently, was charged 1 0 0 parts by weight vinyl chloride, after performing the pre-mixed by stirring net撹拌所main power 0. 9 5 kWZm ^{3 3} 0 minutes, and homogenized in a two-stage high-pressure homogenizer, or less Polymerization was performed in the same manner as in Comparative Example 1 to obtain a vinyl chloride resin (B) for paste processing.

Table 1 shows the evaluation results of the vinyl chloride resin (B) and the evaluation results of a mixture of 85 parts by weight of the resin (B) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Example 2

In a premixer, 120 parts by weight of water was charged, and while stirring at 28 ° C, 0.3 part by weight of lauryl alcohol (melting point: 25 ° C) was added, and then 0.6 part by weight of sodium dodecylbenzenesulfonate was added. An emulsion was prepared by adding parts by weight. Next, 0.07 parts by weight of a 50% by weight n-hexane solution of diisopropylpropylperoxydicarbonate, 0.2 part by weight of lauryl alcohol and sodium dodecylbenzenesulfonate were added thereto. 0.2 parts by weight were added, and nitrogen replacement and deaeration under reduced pressure were repeated twice each. Subsequently, 100 parts by weight of vinyl chloride was charged, and a vinyl chloride resin for paste processing (C) was obtained in the same manner as in Example 1 below. Table 1 shows the evaluation results of the vinyl chloride resin (C) and the evaluation results of a mixture of 85 parts by weight of the resin (C) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Note 1) 15% by weight of small particles blended: 15% by weight of the small particle vinyl chloride resin obtained in Reference Example 1 based on the total weight of vinyl chloride resin When 30% by weight of the small particles obtained in Reference Example 1 based on the total weight of the resin was added to Comparative Example 1, the particle diameter giving a maximum value of a large particle diameter of 0.95 m was small. The particle size that gives the maximum value of the particle size is 0.3 / m, the particle ratio of the average particle size is 0.5 / m or less is 33% by weight, but the sol separates outflow of 3 g / 100 seconds Does not change. As is evident from Table 1, the vinyl chloride resin of the present invention gives a low viscosity sol with a high amount of Sperper's outflow, and the blending of small particles allows for both the viewpoint of Sperper's outflow and B-type viscosity, that is, high shear rate. The viscosity can be further reduced at both low and low shear rates. A low-viscosity sol cannot be obtained.

Comparative Example 2

In a 10 liter stainless steel stirrer and jacket pressure-resistant reactor with a jacket, 120 parts by weight of deionized water, 0.8 part by weight of sodium lauryl sulfate, lauryl alcohol (melting point 25 ° C) 0. 5 parts by weight, 0.06 parts by weight of a toluene solution of 70% by weight of di-2-ethylhexylperoxydiene carbonate was charged, and nitrogen replacement and degassing under reduced pressure were repeated twice. Thereafter, 100 parts by weight of vinyl chloride were charged, and the mixture was stirred at 28 ° C. for 30 minutes with stirring at a required power of 0.95 kWZm ³ for 30 minutes to perform preliminary mixing. After homogenizing this pre-mixed liquid with a two-stage homogenizer, transfer it to another 10 liter degassed pressure-resistant reactor similar to the above, and agitate it under gentle conditions for the purpose of heat transfer. The temperature was raised, and fine suspension polymerization was performed at 47 ° C.

When the polymerization conversion reached 90% by weight, the mixture was cooled and unreacted monomers were removed to obtain a stable aqueous dispersion of polymer particles with almost no scale. Next, the polymer particle aqueous dispersion was dried with a spray drier and then pulverized with a hammer mill to obtain a vinyl chloride resin (D) for paste processing.

Table 2 shows the evaluation results of the vinyl chloride resin (D) and the evaluation results of a mixture of 85 parts by weight of the resin (D) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Example 3

In Comparative Example 2, 70% of di-2-ethylhexylperoxydicarbonate was used. Vinyl chloride resin for paste processing, in the same manner as in Comparative Example 2, except that 0.06 parts by weight of the toluene solution of 0% by weight was added at 20 minutes of the premixing time of 30 minutes. (E) was obtained.

Table 2 shows the evaluation results of the vinyl chloride resin (E) and the evaluation results of a mixture of 85 parts by weight of the resin (E) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Example 4

In Comparative Example 1, 0.07 parts by weight of a 50% by weight solution of diisopropylpropylperoxydicarbonate in n-xane was added at the time when 20 minutes of the premixing time of 30 minutes had elapsed. A vinyl chloride resin for paste processing (F) was obtained in the same manner as in Comparative Example 1 except that the addition was performed.

Table 2 shows the evaluation results of the vinyl chloride resin (F) and the evaluation results of a mixture of 85 parts by weight of the resin (F) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. Five

In Comparative Example 2, 0.06 parts by weight of this toluene solution was used as the radical initiator instead of 0.06 parts by weight of a 70% by weight toluene solution of di-2-ethylhexyl peroxide. And 0.06 parts by weight of water and 0.012 parts by weight of sodium lauryl sulfate were treated with a high-speed stirrer at 100 O rpm for 1 minute, except that an emulsified radical initiator was used. In the same manner as in Comparative Example 2, a vinyl chloride resin for paste processing (G) was obtained.

Table 2 shows the evaluation results of the vinyl chloride resin (G) and the evaluation results of a mixture of 85 parts by weight of the resin (G) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Example 6

In Comparative Example 1, instead of 0.07 parts by weight of a 50 wt% n-hexane solution of diisopropylisopropyloxycarbonate as a radical initiator, 0.07 parts by weight of this n-hexane solution was used. Parts and water 0.07 parts by weight and sodium lauryl sulfate 0.0 A vinyl chloride resin for paste processing was prepared in the same manner as in Comparative Example 1 except that an emulsified radical initiator obtained by treating 14 parts by weight with a high-speed stirrer at 100 O rpm for 1 minute was used. H).

Table 2 shows the evaluation results of the vinyl chloride resin (H), and the evaluation results of a mixture of 85 parts by weight of the resin (H) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Comparative Example 3

In Comparative Example 2, 0.06 parts by weight of a 70% by weight toluene solution of di (2-ethylhexyl) peroxydicarbonate was divided into 0.05 parts by weight and 0.01 parts by weight. In the same manner as in Comparative Example 2, except that the former was added at the initial stage and the latter was added at the time when 20 minutes of the premixing time of 30 minutes had elapsed, a vinyl chloride resin (I) for paste processing was obtained. Was.

Table 2 shows the evaluation results of the vinyl chloride resin (I) and the evaluation results of a mixture of 85 parts by weight of the resin (I) and 15 parts by weight of the small-particle vinyl chloride resin obtained in Reference Example 1. .

Table 2 1

Note 1) 15% by weight of small particles blended: 15% by weight of the small particle vinyl chloride resin obtained in Reference Example 1 based on the total weight of vinyl chloride resin

Table 2

Industrial applicability

The vinyl chloride resin for paste processing of the present invention can provide a low-viscosity plastisol at a high shear rate even if the content of the plasticizer is relatively small. It is.

Further, according to the method of the present invention, the vinyl chloride resin for paste processing having the above excellent performance can be produced extremely efficiently.

Further, the plastizole of the present invention containing the above-mentioned vinyl chloride resin for pasting has a low viscosity at both high and low shear rates, and is excellent in processability.

Claims

The scope of the claims

1. A vinyl chloride resin for paste processing, in which the particle size measured by laser diffraction is continuously and widely distributed at least in the range of 0.2 to 6 zm, and has two maximum values frequently. The particle size that gives the maximum value of the group of small particles is 0.2 to 0.5 m, the particle size that gives the maximum value of the group of large particles is 1.5 to 4.0 zm, and the overall average particle size The particles have a particle size distribution of 1.3 to 4. The particles having an average particle size of 0.5 zm or less have a particle size distribution of 5 to 40% by weight, and 100 parts by weight of the resin and di-2-ethylhexyl phthalate. A paste-processed vinyl chloride resin characterized in that the paste obtained by mixing with 45 parts by weight of a paste has a separate outflow of 3 gl 00 seconds or more.

2. A container equipped with a stirrer is charged with an aqueous medium, an emulsifier, an emulsifier, an oil-soluble radical initiator, and vinyl chloride or an unsaturated monomer copolymerizable with vinyl chloride, and preliminarily mixed. In the method of homogenizing a mixed solution with a homogenizer and transferring it to a polymerization vessel to perform fine suspension polymerization, emulsification is performed by using at least half of an emulsifier in advance and at least half of an emulsifier in the presence of an aqueous medium. After preparing an emulsion, the oil-soluble radical initiator, the remaining emulsifier and / or emulsifier if both are present, and vinyl chloride or an unsaturated monomer copolymerizable therewith with vinyl chloride 2. The method for producing a vinyl chloride resin for paste processing according to claim 1, wherein the mixture is added to the mixture and premixed.

3. An aqueous medium, an emulsifier, an oil-soluble radical initiator, vinyl chloride or vinyl chloride and an unsaturated monomer copolymerizable therewith are charged into a container equipped with a stirrer, and preliminarily mixed. A method of homogenizing with a homogenizer, transferring to a polymerization vessel and performing fine suspension polymerization, characterized in that at least 20% by weight of the oil-soluble radical initiator used is added in the latter half of the premixing time. The method for producing a vinyl chloride resin for paste processing according to claim 1.

4. An aqueous medium, an emulsifier, an oil-soluble radical initiator, vinyl chloride or vinyl chloride and an unsaturated monomer copolymerizable therewith are charged into a vessel equipped with a stirrer, and premixed, and then premixed. The liquid is homogenized by a homogenizer, transferred to a polymerization vessel, and 2. The method for producing a vinyl chloride resin for paste processing according to claim 1, wherein in the method of turbid polymerization, the oil-soluble radical initiator is added in an emulsified state and premixed.

5. Vinyl chloride comprising 60 to 100% by weight of the vinyl chloride resin for paste processing according to claim 1 and 0 to 40% by weight of a vinyl chloride resin having an average particle size of 0.1 to 0.4 m. A vinyl chloride resin blastisol, comprising 100 parts by weight of a resin mixture and 20 to 80 parts by weight of a plasticizer.