JPH05202197A - Production of vinyl chloride resin for paste - Google Patents

Abstract

PURPOSE:To provide a vinyl chloride resin for paste, having high bulk specific gravity, excellent fluidity, a small amount of fine powder produced, ready handleability and not deteriorating operation environment. CONSTITUTION:In producing a vinyl chloride resin for paste by subjecting a monomer consisting essentially of vinyl chloride to emulsion polymerization or micro suspension polymerization to give an aqueous dispersion of vinyl chloride-based polymer and spray-drying the dispersion, 0.2-15 pts.wt. plasticizer based on 100 pts.wt. of the polymer is added to the aqueous dispersion.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a vinyl chloride resin. Specifically, it relates to a method for producing a vinyl chloride resin for paste.

[0002]

2. Description of the Related Art Usually, a vinyl chloride resin for paste has a unit particle diameter of 0.1 μm obtained by emulsion polymerization or micro suspension polymerization of vinyl chloride or a monomer mixture mainly containing vinyl chloride in the presence of a surfactant. If necessary, a surfactant or fine particles of a polymer of the same kind are added to an aqueous dispersion of a vinyl chloride polymer having a particle size of 2 μm to 2 μm, and then spray-dried to obtain a polymer having an average particle size of 30 to 60 μm. Use powder and granules. To process a vinyl chloride resin into a paste, the powder or granules may be used as they are, or coarse particles may be crushed or classified, and then a plasticizer and optionally a heat stabilizer and a filler may be added. Mix with the agent to make paste sol.

[0003]

However, since the powder and granules obtained by spray drying are agglomerates of fine particles, the powder and granules contained in the obtained powder and granules are not transferred to the dryer when they are taken out from the dryer. By crushing or classifying operation for removing coarse particles, the aggregated particles are destroyed and the number of fine particles increases. As a result, the bulk specific gravity and the fluidity are lowered, and the workability is deteriorated.
Further, the scattering of the fine powder also deteriorates the working environment.

The present invention provides a method for producing a vinyl chloride resin for a paste, which has a high bulk specific gravity, good fluidity and excellent workability, and in which the produced powder and granules do not easily become fine powder.

[0005]

DISCLOSURE OF THE INVENTION The present invention is based on vinyl chloride or vinyl chloride, which is obtained by emulsion polymerization or microsuspension polymerization of a mixture of vinyl chloride and other unsaturated compounds copolymerizable therewith. In the method for producing a paste vinyl chloride resin for spray-drying an aqueous dispersion of a vinyl-based polymer,
A method for producing a vinyl chloride resin for a paste, characterized in that 0.2 to 15 parts by weight of a plasticizer is present per 100 parts by weight of the polymer in the aqueous dispersion.

The proportion of vinyl chloride in the mixture of the present invention mainly composed of vinyl chloride and the unsaturated compound copolymerizable therewith is 50% by weight or more.

The unsaturated compound which can be copolymerized is a compound having at least one so-called ethylenically unsaturated bond, and there is a monofunctional compound having one bond or a polyfunctional compound having two or more bonds. .

Examples of monofunctional compounds include fatty acid vinyl esters, alkyl vinyl ethers, (meth) acrylic acid alkyl esters, acrylonitrile, styrene, ethylene and its derivatives, propylene and the like.

Examples of polyfunctional compounds are diallyl esters of dibasic acids such as diallyl phthalate, diallyl maleate and diallyl adipate: diallyl ether, triallyl cyanurate, triallyl trimellitate, ethylene glycol divinyl ether, octadeca. Didivinyl ether, etc. Trivinyl ethers: Di (meth) of polyhydric alcohols such as ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate and dimethylene glycol di (meth) acrylate.
Acrylic esters: Tri (meth) acrylic esters of polyhydric alcohols such as trimethylolpropane tri (meth) acrylate and tetramethylolmethane tri (meth) acrylate: bismethacryloyl, diethylene phthalate, 1,3,5-triacryloyl hexa Examples thereof include oligomers such as hydrotriazine, allyl (meth) acrylate and polybutadiene, and one or more of the above polyfunctional compounds may be used in combination. Further, the amount of the polyfunctional compound added to the polymerization system may be determined depending on the type and the polymerization temperature according to the allowable amount of the fine gel insoluble in the produced tetrahydrofuran, but is generally 5% by weight or less.

The emulsion polymerization and microsuspension polymerization of the present invention may be carried out by known methods and are not particularly limited. By these methods, an aqueous dispersion of a vinyl chloride polymer is obtained.

The plasticizer used in the present invention may be a known one, such as di-n-butyl phthalate or di-n-butyl phthalate.
i-butyl phthalate, dihexyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2
Dialkyl esters of phthalic acid such as -ethylhexyl phthalate, di-i-octyl phthalate, di-n-nonyl phthalate, di-i-nonyl phthalate, di-n-decyl phthalate, di-i-decyl phthalate: di-i
-Dialkyl esters of adipic acid such as butyl adipate, di-n-octyl adipate, di-2-ethylhexyl adipate, di-i-octyl adipate, di-n-decyl adipate: adipic acid polyester, sebacic acid polyester, etc. One of the above plasticizers
You may use together 2 or more types.

The amount of plasticizer added is about 0.2 to 15 parts by weight, preferably 0.3 to 10 parts by weight, per 100 parts by weight of the polymer in the aqueous dispersion. If the amount of the plasticizer is less than 0.2 parts by weight, the effect will not be sufficiently exhibited, and if it exceeds 15 parts by weight, the effect of preventing particle breakage of the powder and granules is large,
The adhesiveness of the powder and granules becomes large, and a lump of the powder and granules is generated, which causes problems such as adhesion inside the dryer, which is not preferable.

The method of adding the plasticizer is not particularly limited as long as it is present in the aqueous dispersion, that is, it is added at any stage from the production of the aqueous dispersion to the drying. In the polymerization stage, a predetermined amount of plasticizer may be added at any of the initial stage, the middle stage and the final stage of the polymerization. Further, when it is added to the aqueous dispersion after polymerization, it is preferable that the plasticizer is dispersed in an aqueous solution of a surfactant and then a predetermined amount thereof is added and well mixed.

The spray dryer used in the present invention may be a well-known one used for producing a vinyl chloride resin for paste. For example, the spraying type may be a rotary disk type atomizer, a two-fluid nozzle type or a pressure nozzle type. But it's okay. The drying air need only be taken from the atmosphere and does not require any additional humidity control. Drying conditions such as a dryer inlet / outlet temperature of the drying air, an air flow rate, and a supply amount of the vinyl chloride polymer aqueous dispersion may be the same as those of the ordinary vinyl chloride polymer aqueous dispersion. For example, in the case of the type of spraying with a rotating disk type atomizer, the hot air temperature at the dryer inlet is 140 to 1
90 ° C., so that the outlet hot air temperature is 50 to 70 ° C.
The supply amount of the vinyl chloride polymer-based aqueous dispersion may be adjusted. Due to this drying, the average particle size is usually 20μ to 100μ.
The powder and granules are obtained.

The obtained granular material has a large bulk specific gravity and a small amount of fine powder. If there are coarse particles therein, they may be removed by a known sieving method or a pulverizing method. Among them, a fixed-mesh wind type sieve is suitable for sieving the powder or granular material obtained by the production method of the present invention. Further, the powder or granular material obtained by the production method of the present invention produces less fine powder even if coarse particles are crushed.

[0016]

INDUSTRIAL APPLICABILITY The vinyl chloride resin for paste obtained by the method of the present invention has a smaller amount of fine particles generated in the classifying and pulverizing steps, a larger bulk specific gravity and a higher fluidity than ordinary spray-dried resins. Has excellent powder characteristics. Therefore, handling and workability are good. Moreover, a uniform paste can be obtained and there is no problem in its usage. Also, the physical properties of the sol are the same as those obtained by drying without adding a plasticizer, such as dispersibility in a plasticizer and viscosity, and in addition, it is not necessary to use special drying conditions and the productivity is impaired. Nor.

[0017]

[Examples] Powder properties and sol physical properties were measured by the following methods. -Average particle size: The particle size distribution was measured with a laser beam revolving particle sizer (Malvern Co., Ltd., Master Sizer) to determine the average particle size and the amount of fine particles of 10 μm or less. -Bulk specific gravity: measured according to JIS K-6721. Angle of repose: Measured with a powder tester manufactured by Hosokawa Powder Engineering Laboratory Co., Ltd.・ Disintegration property of powder and granules: The pressure of the air jet type crusher was set to 3 kg / cm ^{2 on} the primary side and 2 kg / cm ² on the secondary side to pulverize, and the ratio of 10 μm or less obtained from the particle size distribution was obtained. (The smaller the amount is 10 μm or less, the less the particles are likely to collapse.) Sol viscosity: Di-2-ethylhexyl phthalate in an amount such that the total amount of the plasticizer is 60 parts by weight with respect to 100 parts by weight of the polymer is added at 25 ° C. , In a constant temperature and humidity room with a relative humidity of 55%,
The mixture was kneaded with a ladle machine to form a paste, and the viscosity after standing for 4 hours was measured. Rotor # 4 was measured at 6 rpm with a Brookfield BL viscometer.

Example 1 A 100-liter glass-lined polymerization vessel was degassed, and 40 kg of deionized water, 25 kg of vinyl chloride monomer, 150 g of sodium dodecylbenzenesulfonate, 100 g of stearyl alcohol, and di-2 ethylhexyl peroxydicarbonate. 0 g was charged, and after homogenization treatment, the temperature was raised to 53 ° C. to initiate polymerization. After 15 hours, the unreacted monomer was removed when the pressure inside the polymerization vessel dropped by 0.5 Kg / Cm ² . To the obtained vinyl chloride polymer aqueous dispersion, 100 g of polyoxyethylene nonyl phenyl ether and 0.2% by weight of a solution of sodium dodecylbenzenesulfonate in 20% by weight of di-2 ethylhexyl phthalate (hereinafter referred to as DOP) were dispersed. The resulting liquid was added so that DOP was 1 part by weight with respect to 100 parts by weight of the polymer. Next, the aqueous dispersion was spray-dried with a rotating disk type atomizer (diameter 12 cm), manufactured by NIRO (Niro) production minor type (tower diameter 1.2 m, tower length 1.0 m, straight cone part, conical part). The powder was obtained by drying at an inlet hot air temperature of 180 ° C. and an outlet hot air temperature of 60 ° C. at an angle of 60 degrees. The evaluation results are shown in Table 1.

Examples 2 to 3 Powders and granules were obtained by drying under the same conditions as in Example 1 except that DOP was changed to the amounts shown in Table 1. The evaluation results are shown in Table 1.

Examples 4 to 7 The vinyl chloride resin aqueous dispersion for pastes used in Example 1 was replaced by di-n-butyl phthalate (DBP) instead of DOP.
Abbreviated), di-isononyl phthalate (abbreviated as DINP), di-n octyl adipate (abbreviated as DOA), polyester plasticizer with an average molecular weight of about 1600 (trade name SP
-105: Dry powder was obtained under the same conditions as in Example 1 except that 1 part each of Sanken Kako Co., Ltd. (referred to as PPS) was added. The evaluation results are shown in Table 1.

Example 8 A 100-liter glass-lined polymerization vessel was degassed, and 40 kg of deionized water, 25 kg of vinyl chloride monomer, 150 g of sodium dodecylbenzenesulfonate, 100 g of stearyl alcohol, and di-2 ethylhexyl peroxydicarbonate. Charge 0 g and DOP 250 g, and after homogenization treatment, 5
The temperature was raised to 3 ° C. to initiate polymerization. After 15 hours, the unreacted monomer was removed when the pressure inside the polymerization vessel dropped by 0.5 Kg / Cm ² . 100 g of polyoxyethylene nonyl phenyl ether was added to the obtained vinyl chloride polymer aqueous dispersion, and the powder was dried under the same conditions as in Example 1 to obtain a powder. The evaluation results are shown in Table 1.

COMPARATIVE EXAMPLE 1 The vinyl chloride resin aqueous dispersion for paste used in Example 1 was dried as it was under the same conditions as in Example 1 without adding a plasticizer to obtain a granular material. The evaluation results are shown in Table 1.

[0023]

[Table 1]

Claims (1)

[Claims] 1. Mainly vinyl chloride or vinyl chloride,
Emulsion polymerization or a mixture of other unsaturated compounds copolymerizable with it, an aqueous dispersion of a vinyl chloride polymer obtained by microsuspension polymerization, in a method for producing a paste vinyl chloride resin spray-dried , Polymer 1 in the aqueous dispersion
A method for producing a vinyl chloride resin for paste, characterized in that 0.2 to 15 parts by weight of a plasticizer is present per 00 parts by weight.