JPS58120612A - Emulsion polymerization of vinyl chloride - Google Patents

Abstract

PURPOSE:To prepare a vinyl chloride polymer having excellent color tone, by the emulsion polymerization of vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith, in the presence of a catalyst comprising alpha-cumyl peroxyneodecanoate. CONSTITUTION:Vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith (e.g. ethylene) is mixed with a polymerization catalyst comprising alpha-cumyl peroxyneodecanoate and if necessary other catalyst (e.g. dioctyl peroxydicarbonate). The amount of the alpha-cumyl peroxyneodecanoate in the catalyst is preferably 10-100wt%. The mixture is mixed with 80-300pts.wt. (based on 100pts.wt. of vinyl chloride) of water, 0.1-5pts.wt. of an emulsifier (e.g. alkylsulfonic acid salt) and an emulsification assistant (e.g. lauryl alcohol), and if necessary with a polymerization assistant, and subjected to the emulsion polymerization at 35-70 deg.C to obtain the objective vinyl chloride copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymerization method for obtaining polymers (hereinafter referred to as vinyl chloride polymers). More specifically, when emulsion polymerizing vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable with vinyl chloride, a flexible composition can be obtained by chlorination using d-cumyl peroxyneodecanate as a polymerization catalyst. Because of this, it is widely praised as a soft vinyl chloride resin. These soft vinyl chloride resins are used to produce a variety of processed products, including transparent, opaque, white, and colored products, but recently, light colors have become particularly popular.

However, when the hue of vinyl chloride polymers deviates from white and is made into a 0-processed plain product, there is a drawback that the color of the product is not vivid and becomes dull. It has been desired to improve the hue of vinyl chloride polymers.

An object of the present invention is to provide a method for emulsion polymerization of vinyl chloride with good hue.

As a result of intensive studies on polymerization methods, the present inventors have discovered that vinyl chloride polymers with good hue can be obtained by using α-cumyl peroxyneodecanate as a polymerization catalyst, and have arrived at the present invention.

According to the present invention, when emulsion polymerizing vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith, α is used as a polymerization catalyst.
- A method for emulsion polymerization of vinyl chloride with good hue, characterized by using cumyl peroxyneodecanate.

is provided.

In the present invention, α-cumyl peroxyneodecanate is used as a polymerization catalyst, but it may be used in combination with other catalysts in order to equalize the polymerization reaction rate. Other catalysts that may be used in combination include dialkyl peroxydicarbonates such as diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, dilauryl peroxydicarbonate, dicetyl peroxydicarbonate, and ditert-butyl peroxydicarbonate. Carbonate, di(2-ethoxyethyl) peroxydicarbonate, di(2-methoxypropyl) peroxydicarbonate, dibenzyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, ditertiarybutylcyclohexyl oxydicarbonate ), etc., 2゜2'-azobis-2,4-dimethylvaleronitrile, 2.2'-azobis-4-methoxy-2,4
Examples include azo compounds such as -dimethylvaleronitrile, tert-butyl peroxyneodecanate, di-tert-butyl oxalate, and imbutyryl peroxide.

However, as a matter of course, it is an essential requirement that α-cumyl peroxyneodecanate be included in the combination. Although there is no limit to the number of catalysts to be combined, a combination of two to four types of catalysts is substantially preferable.

The greater the proportion of cumyl peroxyneodecanate in the catalysts used in combination, the better the hue of the vinyl chloride polymers. The proportion of α-cumyl peroxyneodecanate in the catalyst used in combination is 1
It is preferably 0 to 100% by weight, and more preferably 20 to 100% by weight.

The amount of catalyst used in the homopolymerization of vinyl chloride in the present invention is determined by the type of catalyst, polymerization temperature, heat removal capacity of the polymerization machine (including the heat removal capacity of both equipment), etc. Per 100 parts by weight of vinyl, the amount of α-cumyl peroxyneodecanate is 0005-03 parts by weight, and the combined catalyst is 5-03 parts by weight of O,OO.

If the amount of the catalyst used is less than 5 parts by weight of O or OO, the effect as a catalyst will be low, and if it exceeds 0.3 parts by weight, it will be difficult to control the polymerization rate and there is a risk that the polymerization reaction will run out of control.

Furthermore, in the present invention, the amount of the catalyst used in the copolymerization of vinyl chloride is similarly determined by the type of comonomer, the polymerization temperature, the heat removal capacity of the polymerization machine (including the heat removal capacity of both zone equipment), etc. is usually vinyl chloride and comonomer 10
0 parts by weight of α-cumyl peroxyneodecanate
005 to 30 parts by weight, combined catalysts are O, OO
It is 5 to 30 parts by weight.

If the amount of the catalyst used is less than 5 parts by weight of O or OO, the effect as a catalyst will be low, and if it exceeds 30 parts by weight, it will be difficult to control the polymerization rate and there is a risk that the polymerization reaction will run out of control.

By using the catalyst system of the present invention, vinyl chloride polymers with good hue can be obtained.

The method of the present invention can be applied to base resin manufacturing methods generally practiced in the art. That is, the ratio of vinyl chloride to water is generally 80 to 3 parts by weight of water to 100 parts by weight of vinyl chloride.
00 parts by weight, and the polymerization temperature is usually 35 to 70°C. In addition to vinyl chloride, other monomers copolymerizable with vinyl chloride such as evaporated ethylene, propylene, l-butene,
1-pentene, 1-hexene, 1-heptene, l-octene, 1-nonene, 1-decene, 1-undecene, 1-
d-olefins having 2 to 30 carbon atoms such as dodecene, 1-tridecene, 1-tetradecene, acrylic acid or its esters, methacrylic acid or its esters, fumaric acid or its esters, maleic acid or its esters, acetic acid Vinyl, vinyl propionate, alkyl vinyl ether compounds, and mixtures thereof can be present together.

In the present invention, known emulsifiers are used.

The emulsifier used in the present invention may be one of ordinary anionic surfactants such as alkyl sulfonates, alkylaryl sulfonates, alkyl alcohol sulfate salts, fatty acid salts, and dialkyl sulfosuccinates. Or two or more types can be mentioned. These salts are generally alkali metal salts. In addition to anionic surfactants, nonionic surfactants such as glycerin esters, glycol esters, or sorbitan esters of higher fatty acids, higher alcohol condensates, higher fatty acid condensates, polypropylene condensates, etc., or cetyl as an emulsifying agent. One or more kinds of higher alcohols such as alcohol and lauryl alcohol, higher fatty acids such as lauric acid, palmitic acid, and stearic acid, or esters thereof can be used in combination with the anionic surfactant. 5. The total amount of these emulsifiers is 0.1 to 5 parts by weight per 100 parts by weight of monomer.

Further, aromatic hydrocarbons, higher aliphatic hydrocarbons, halogenated hydrocarbons such as chlorinated paraffin, PH regulators such as sodium bicarbonate and ammonia, chain transfer agents, etc. may be used in combination as polymerization aids.

The binder, emulsifier, polymerization initiator, water, vinyl chloride monomer and, if necessary, other polymerization aids must be premixed prior to the polymerization reaction and then homogenized by applying high shear forces. The homogenization can be carried out using known homogenization methods such as a one-stage or two-stage high-pressure pump, a colloid mill, a homomixer, high-pressure jetting through a nozzle or orifice, and ultrasonic waves.

The present invention will be specifically explained below using Examples and Comparative Examples, but these are merely illustrative and do not limit the scope of the present invention. Note that parts in Examples and Comparative Examples are parts by weight.

Example 1 450 ml of distilled water was added to a pre-mixing container with a stirrer with a volume of 10,004 ml.
3 kg of sodium lauryl sulfate, 6 kg of lauryl alcohol, and 0.12 kg of α-cumyl peroxyneodecane, and 0.06 kg of dioctyl peroxydicarbonate were charged, and the space was replaced with nitrogen. After that, the pressure inside the container was reduced, 300 kg of vinyl chloride monomer was charged, and the mixture was stirred and mixed for 30 minutes while maintaining the temperature inside the container at 30°C. Next, the liquid in the preliminary stirrer was homogenized using a pressure homogenizer, and then a vacuum pump was used to homogenize the liquid in the pre-stirrer. llf1gabs
A glass-lined polymerization reactor with a volume of
The reaction continued in the trench where the pressure reached Kg/cr/l G pressure. After the reaction was completed, unreacted monomers were collected, and the polymer latex was dried with a spray dryer and then ground to obtain a product.

The obtained polymer particles had particle sizes widely distributed in the range of 0.2 to 2 μm, and had suitable performance as a base resin.

Dioctyl phthalate 6 to 100 parts of this base resin
Plastisol was prepared by adding 0 part of plastisol, 1 part of organotin stabilizer, and 2 parts of titanium oxide, and the plastisol was made to a thickness of 1 layer using an applicator on a ferro plate, and cured in a gear oven at 180°C for 10 minutes to obtain a film. . The yellowness was measured using a colorimeter and found to be 1.3, and a clear white color was observed visually.

Comparative Example I α-cumyl baroxyneodecane) 0.12 Ky
A film was obtained in the same manner as in Example 1, except that 0.2 kg of 2,2'-azobis-2,4-dimethyl (2,2'-azobis-2,4-dimethylchloride) was used instead. The degree of yellowness was 43, and a pale yellow color was observed visually.

Example 2 450 ml of distilled water was added to a pre-mixing container with a stirrer having a volume of 10,004 ml.
Kg, sodium lauryl sulfate 3Kg, -y uryl alcohol 3Kg, myristyl alcohol 3Ky
and 0- d-cumyl peroxyneodecanate 0.15
After charging 270 kg of vinyl chloride monomer and replacing the space with nitrogen, the pressure inside the container was reduced to 270 kg of vinyl chloride monomer and 30 kg of vinyl acetate.
g, and stirred and mixed for 30 minutes while maintaining the temperature inside the container at 30°C. Next, after homogenizing the liquid in the preliminary stirrer with a pressure homogenizer, 351111 [1g
The mixture was charged into a glass-lined polymerization reactor having a capacity of 1000-e under reduced pressure of abS, and the reaction was continued at 50° C. until the pressure reached 5 KgA1itG pressure.

After the reaction was completed, unreacted monomers were collected, and the polymer latex was dried using a spray dryer and then ground to obtain a product.

The obtained polymer particles had a wide distribution in particle size of 02 to 3 μm and had suitable performance as a base resin. To 100 parts of this base resin, 60 parts of dioctyl phthalate, 1 part of an organic tin stabilizer, and 2 parts of titanium oxide were added to adjust plastinol, and the thickness was adjusted to 1 inch using an applicator on a ferro plate, and heated at 160°C in an open gear. A film was obtained by curing for 10 minutes. The degree of yellowness was measured using a colorimeter, and a clear white color was observed with the naked eye at a value of 7 and 1.1.

Comparative Example 2 0.15 kg of d-cumyl peroxyneodecanate was replaced with 0.17 kg of dioctyl peroxydicarbonate.
A film was obtained in the same manner as in Example 1, except that K9 was used. The degree of yellowness was 3.9, and a pale yellow color was observed by visual inspection.

patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] d-cumyl peroxyneodecanate is used as a polymerization catalyst in the emulsion polymerization of l-vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith. Emulsion polymerization method.