JPH09176419A - Manufacturing method of vinyl chloride resin - Google Patents

Abstract

(57) [PROBLEMS] To provide a process for producing a vinyl chloride resin having good thermal stability, which is unlikely to cause a decrease in bulk specific gravity due to charging. SOLUTION: In producing a vinyl chloride resin, a slurry containing a vinyl chloride resin, a cake obtained after dehydrating the slurry or a resin powder obtained by drying the cake, A compound having a specific structure is added in an amount of 0.001 to 100 parts by weight of the vinyl chloride resin.
A method for producing a vinyl chloride resin, which comprises adding 0.5 part by weight.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a vinyl chloride resin by a suspension polymerization method,
More specifically, it relates to a method for producing a vinyl chloride resin having excellent powder fluidity.

[0002]

2. Description of the Related Art Vinyl chloride resins are generally produced by a suspension polymerization method, and after separation from a slurry, drying, etc., they are conveyed by air transportation and then stored or packed.

However, the vinyl chloride resin is charged with static electricity due to friction with itself or other substances during transport and bagging, and its fluidity is lowered, and its bulk specific gravity is higher than that of the vinyl chloride resin immediately after production. Since it decreases, it becomes extremely difficult to handle, and there is a problem that work is seriously hindered. As a method for reducing the adverse effect of such polymer charging, conventionally, a method of adding a surfactant to a vinyl chloride resin or a method of blowing steam into the vinyl chloride resin to adjust the humidity has been used.

[0004]

However, in the conventional method of adding a surfactant, not only the decrease in bulk specific gravity due to electrification of the resin cannot be sufficiently prevented, but also the thermal stability and the initial stage of the resin are improved. It has the drawback of adversely affecting the colorability. In addition, the method of blowing steam has drawbacks such as an increase in required labor force and complication of equipment.

Therefore, an object of the present invention is to provide a method for producing a vinyl chloride resin having good quality, which is less likely to cause a decrease in bulk specific gravity due to electrification by adding a specific compound. is there.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that addition of a specific compound makes it difficult for the vinyl chloride resin to be reduced in bulk specific gravity due to charging. Moreover, a method for producing a vinyl chloride resin having good quality has been found, and the present invention has been completed.

That is, according to the present invention, when a vinyl chloride resin is suspension polymerized in an aqueous medium to produce a vinyl chloride resin, the vinyl chloride resin-containing slurry is obtained by dehydrating the slurry. 0.001 to 0.5 parts by weight of the compound represented by the following formula (1) in 100 parts by weight of the vinyl chloride resin described above is added to the obtained cake or the resin powder obtained by drying the cake. The present invention provides a method for producing a vinyl chloride-based resin, which is characterized by adding a part thereof.

H (OCH ₂ CH ₂ ) _n OCOR (1) (wherein R represents an alkyl group having 1 to 20 carbon atoms, and n represents an integer of 1 or more.) The present invention is described in detail below. To do.

In the present invention, the vinyl chloride resin is produced by the suspension polymerization method.

Examples of the vinyl chloride resin in the present invention include a vinyl chloride homopolymer resin and a vinyl chloride copolymer resin.

In the present invention, the vinyl chloride-based monomer for producing the vinyl chloride-based resin is a vinyl-based monomer or a vinyl-based monomer which is copolymerizable with the vinyl chloride monomer and the vinyl chloride monomer. Mention may be made of mixtures with the body. Examples of the vinyl monomer copolymerizable with the vinyl chloride monomer include alkyl vinyl esters such as vinyl acetate; alkyl vinyl ethers such as cetyl vinyl ether; α-monoolefin monomers such as ethylene and propylene. And alkyl acrylates such as methyl acrylate, ethyl acrylate and propyl acrylate; and methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate and propyl methacrylate.

The suspension polymerization of the vinyl chloride resin in the present invention may be carried out by a generally known method, for example, in the presence of a vinyl chloride monomer suspension agent and a polymerization initiator.
A method of polymerizing in an aqueous medium can be mentioned, and a slurry containing a vinyl chloride resin can be obtained by such a suspension polymerization method.

In the present invention, a slurry containing a vinyl chloride resin, a cake obtained by dehydrating the slurry, or a resin powder obtained by drying the cake is added by the formula (1). In the compounds shown, R has 1 to 1 carbon atoms.
20 alkyl groups, n is an integer of 1 or more, and any compound can be used as long as it is a compound represented by the formula (1). An alkyl group having 6 to 18 carbon atoms, n is 1 to 20
More preferably, it is an integer of 0. Examples of the compound represented by the formula (1) include polyoxyethylene lauryl ester, polyoxyethylene palmityl ester, polyoxyethylene stearyl ester and the like.

The addition amount of the compound represented by the formula (1) in the present invention is 0.001 to 0.5 part by weight based on 100 parts by weight of the vinyl chloride resin. 0.0
If the amount is less than 01 parts by weight, it is impossible to prevent the bulk density of the resulting vinyl chloride resin from being extremely lowered due to electrification. Further, even if the amount added exceeds 0.5 parts by weight, the desired effect does not increase any more, which is not economical.

In the present invention, the method for adding the compound represented by the formula (1) is as follows: a slurry containing a vinyl chloride resin, a cake obtained after dehydrating the slurry, or a cake obtained by drying the cake. Any method can be used as long as it can be added to the resin powder obtained, and it can be added in the state of powder, solution, dispersion, etc., and can be easily and uniformly added. Since it is possible, it is preferable to add it in the form of a solution or dispersion. The solvent for preparing the solution or dispersion liquid of the compound represented by the formula (1) is not particularly limited, but, for example, water,
Methanol, ethanol, isopropyl alcohol, acetone or a mixed solvent thereof can be used.

[0016]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto.

The resins obtained in Examples and Comparative Examples were evaluated under the conditions shown below.

-Bulk Specific Gravity Measurement Test- The obtained resin was left in a constant temperature and humidity chamber at a temperature of 23 ° C and a relative humidity of 50% for 48 hours, and then the bulk specific gravity was measured by the method of JIS K 6721.

The resin left for 48 hours under the same conditions as above was treated with a Brabender planetary mixer at 60r.
After stirring for 2 minutes at pm, bulk specific gravity was determined by the same method as above, and the antistatic properties were evaluated by comparing them.

-Heat Stability- 100 parts by weight of the obtained resin is blended with 1.0 part of tribasic lead sulfate, 1.5 parts of lead stearate and 0.5 part of calcium stearate, and rolled at 190 ° C. After kneading with a machine for 5 minutes, a sheet with a thickness of 1 mm is prepared, and this sheet is
It was placed in an oven at ℃ and the time until blackening was measured.

Example 1 100 parts by weight of vinyl chloride monomer, 150 parts by weight of deionized water, 0.1 part by weight of partially saponified polyvinyl alcohol and 0.04 part by weight of 2-ethylhexyl peroxydicarbonate were placed in a stainless steel polymerization vessel. Was charged, polymerization was carried out at a temperature of 57 ° C., and when the pressure in the polymerization vessel reached 6.0 kg / cm ² G, unreacted vinyl chloride monomer was recovered and dehydrated to contain 20% by weight of water. A vinyl chloride resin cake was obtained.
To the resin cake thus obtained, 1% aqueous solution of polyoxyethylene lauryl ester was added so that the addition amount of polyoxyethylene lauryl ester was 0.01 part by weight with respect to 100 parts by weight of the resin, and then at 70 ° C. It was fluidized and dried for 2 hours to obtain a vinyl chloride resin.

Table 1 shows the evaluation results of the obtained vinyl chloride resin.
Shown in

The obtained vinyl chloride resin had an excellent antistatic property and did not deteriorate in thermal stability.

Examples 2 to 5 Vinyl chloride resins were obtained in the same manner as in Example 1 except that the addition amount and the addition conditions of the polyoxyethylene lauryl ester were changed to those shown in Table 1.

Table 1 shows the evaluation results of the obtained vinyl chloride resin.
Shown in

The obtained vinyl chloride resin had an excellent antistatic property and did not deteriorate in thermal stability.

Comparative Example 1 A vinyl chloride resin was obtained in the same manner as in Example 1 except that polyoxyethylene lauryl ester was not added.

Table 1 shows the evaluation results of the obtained vinyl chloride resin.
Shown in

The obtained vinyl chloride resin was inferior in antistatic property.

[0030]

[Table 1]

[0031]

INDUSTRIAL APPLICABILITY The present invention relates to a process for producing a vinyl chloride resin having a good thermal stability, which is unlikely to cause a decrease in bulk specific gravity due to electrification, and has a high industrial value.

Claims (1)

[Claims] 1. A suspension-polymerization of a vinyl chloride monomer or a mixture of vinyl-based monomers having vinyl chloride monomer as a main component (hereinafter referred to as vinyl chloride-based monomer) in an aqueous medium, In producing a vinyl chloride resin, a slurry containing the vinyl chloride resin, a cake obtained after dehydrating the slurry, or a resin powder obtained by drying the cake is added with the following formula (1 ) Addition of 0.001 to 0.5 parts by weight of the compound represented by the formula (1) to 100 parts by weight of the vinyl chloride resin is a process for producing a vinyl chloride resin. H (OCH ₂ CH ₂ ) _n OCOR (1) (R in the formula represents an alkyl group having 1 to 20 carbon atoms, and n represents an integer of 1 or more.)