JPH0748407A - Vinyl chloride polymers with good hue and no odor - Google Patents

Abstract

(57) [Summary] [Structure] In aqueous suspension polymerization of vinyl chloride or a mixture of a monomer copolymerizable therewith and vinyl chloride, by using tertiary octyl peroxyneodecanate as a polymerization catalyst. The resulting vinyl chloride polymers have a good hue and are odorless. [Effect] Since the vinyl chloride polymers obtained by using the catalyst system of the present invention have good hue and no odor during processing, they can be suitably used not only in general processed products but also in the food field. In addition, it is possible to maintain a good working environment with no offensive odor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vinyl chloride polymers having a good hue and having no odor. More specifically, vinyl chloride or a mixture of a monomer copolymerizable therewith and vinyl chloride is mixed with a specific polymerization catalyst. The present invention relates to vinyl chloride polymers which are obtained by aqueous suspension polymerization and have good hue and no odor during processing.

[0002]

2. Description of the Related Art Vinyl chloride polymers or copolymers (hereinafter referred to as vinyl chloride polymers) are kneaded with a plasticizer to give a flexible composition, and are widely used as soft vinyl chloride resins. There is. These soft vinyl chloride resins have produced various processed products such as transparent, opaque, white or colored, and recently, particularly light shades have been favored. In addition, the same tendency is observed for hard products.

[0003]

However, when the hue of the vinyl chloride polymers deviates from white, the coloration of the product is not vivid when it is processed into a light shade, and the product has a dull tone. However, there has been a demand for improvement in the hue of vinyl chloride polymers.

The inventors of the present invention have studied the above points, and as a result, as a catalyst giving polymers having an improved hue,
We have found .alpha.-cumylperoxyneodecanate, but have found that the catalyst has the drawback of producing a rather strong characteristic off-flavor similar to acetophenone or phenol during processing of the polymers.

This means that an offensive odor during processing such as application of heat to a roll or an extruder causes deterioration of the working environment and eventually damages the health of the worker, which can be a serious problem.

[0006]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that when tertiary octyl peroxyneodecanoate is used as a polymerization catalyst, it has good hue and no odor during processing. The present invention has been achieved by finding that coalesced products can be obtained. That is, the present invention is a hue obtained by using tertiary octyl peroxy neodecanoate as a polymerization catalyst in aqueous suspension polymerization of vinyl chloride or a mixture of a monomer copolymerizable therewith and vinyl chloride. Vinyl chloride polymers which are good and have no odor.

In the present invention, tertiary octyl peroxyneodecanate is used as a polymerization catalyst, but it may be used in combination with other catalysts to make the polymerization reaction rate uniform. Other catalysts that can be used in combination with tertiary octyl peroxyneodecanate include diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, dilauryl peroxydicarbonate, dicetyl peroxydicarbonate, ditertiary butyl. Dialkyl peroxydicarbonates such as peroxydicarbonate, di (2
-Ethoxyethyl) peroxydicarbonate, di (2
-Methoxypropyl) peroxydicarbonate, dibenzylperoxydicarbonate, dicyclohexylperoxydicarbonate, ditertiarybutylcyclohexylperoxydicarbonate, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2 Examples include azo compounds such as'-azobis-4-methoxy-2,4-dimethylvaleronitrile, tertiary butyl peroxyneodecanate, ditertiary butyl oxalate, and isobutyryl peroxide.

However, as a matter of course, it is an essential requirement that the combination contains tertiary octyl peroxyneodecanate. The number of catalysts to be combined is not limited, but a combination of 2 to 4 types of catalysts is substantially preferable.

The higher the proportion of tertiary octyl peroxyneodecanate in the catalysts used in combination, the better the hue of the vinyl chloride polymers. Also,
The proportion of tertiary octyl peroxyneodecanate in the catalysts used in combination is at least 1.
0% by weight or more, preferably 20 to 100% by weight,
More preferably, it is 50 to 100% by weight. If the proportion of tertiary octyl peroxyneodecanate in the catalyst is less than 10% by weight, the hue improving effect is small and not sufficient.

In the present invention, the amount of the catalyst used for the homopolymerization of vinyl chloride is determined by the type of catalyst, the polymerization temperature, the heat removal capacity of the polymerization machine (including the heat removal capacity of auxiliary equipment), and the like. Usually, 0.005-0.5 parts by weight of tertiary octyl peroxy neodecane per 100 parts by weight of vinyl chloride, and when used in combination with other catalysts and tertiary octyl peroxy neodecane, It is 0.005 to 0.5 part by weight as a catalyst. When the amount of this catalyst used is less than 0.005 parts by weight,
If it exceeds 0.5 parts by weight, it is difficult to control the polymerization rate, and the polymerization reaction may run away.

Further, the amount of the catalyst used for the vinyl chloride copolymerization in the present invention depends on the kind of the comonomer, the polymerization temperature and the heat removal capacity of the polymerization machine (including the heat removal capacity of auxiliary equipment). Usually, 0.005-3.0 parts by weight of tertiary octyl peroxyneodecanate is added per 100 parts by weight of vinyl chloride, and a combination of other catalysts and tertiary octyl peroxyneodecanate is usually used. When used, it is 0.00 as a catalyst
5 to 3.0 parts by weight. The amount of this catalyst used is 0.00
If the amount is less than 5 parts by weight, the effect as a catalyst is small and 3.0
If the amount is more than parts by weight, it is difficult to control the polymerization rate and the polymerization reaction may run away.

By using the above-mentioned catalyst system, it is possible to obtain vinyl chloride polymers having a good hue and no odor during processing, and a method for producing the vinyl chloride polymers is an aqueous suspension generally used in the art. The turbid polymerization method is preferably applicable. In this case, the ratio of vinyl chloride to water is generally 80 to 300 parts by weight of water with respect to 100 parts by weight of vinyl chloride,
The polymerization temperature is usually in the range of 35 to 70 ° C.

Monomers which can be copolymerized with vinyl chloride in addition to vinyl chloride include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-
Octene, 1-nonene, 1-decene, 1-undecene,
C2-C30 α-olefins such as 1-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 And vinyl compounds such as vinyl acetate, vinyl propionate, alkyl vinyl ether, and the like, and mixtures thereof can coexist.

In the production of the vinyl chloride polymers of the present invention, known dispersants other than the above catalysts are used. Usable dispersants are, for example, polyvinyl alcohol, cellulose derivatives, maleic anhydride. Examples thereof include acid-styrene copolymers, maleic anhydride-methyl vinyl ether copolymers and gelatin.

According to the present invention, vinyl chloride polymers having a good hue and no odor can be obtained by the above-mentioned method, particularly by using tertiary octyl peroxyneodecanate as a catalyst. It has become possible to suitably use it for applications in the food field where strict hygiene standards such as coloring and odor are not possible.

[0016]

The present invention will be described in detail below with reference to examples, but these are merely examples and do not limit the scope of the present invention. Further, parts in the examples and comparative examples are parts by weight. In the sensory test method for odor in the examples, a sample prepared by diluting by a batch type air dilution method was measured by an odor bag method by a three-point comparison method, and the odor intensity was determined at 6 levels. The contents of this 6-stage odor intensity display method are as follows: if the odor intensity is 0 in the case of no odor and the odor intensity is 1 to 5 below, 1: odor is barely perceptible. 2: A weak odor that can be understood what odor it is. 3: A smell that can be easily perceived. 4: Strong odor. 5: Strong odor. Displayed as.

Example 1 2250 kg of water and a saponification degree of 80 were placed in a polymerization machine having an internal volume of 7 m ^3.
1.8% of partially saponified polyvinyl alcohol having an average degree of polymerization of 2000 in mol%, 0.45 kg of dioctyl peroxydicarbonate, 0.90 kg of tertiary octyl peroxyneodecanate were charged, and the internal air was removed by a vacuum pump. After that, 2250 kg of vinyl chloride was charged. The polymerization temperature was set to 50.5 ° C., the reaction was allowed to proceed, and the reaction was continued until the internal pressure reached 5 kg / cm ² -G pressure. After the reaction was completed, unreacted monomers were collected, the polymer slurry was discharged, dehydrated and dried to obtain a polymer as a product.

100 parts of the obtained polymer, 30 parts of dioctyl phthalate, 0.3 part of dibutyltin mercaptide and 0.3 part of titanium oxide were mixed and kneaded on a roll at 160 ° C. for 5 minutes to form a 0.6 mm sheet. I took it out. No offensive odor was felt during roll kneading, and the odor intensity according to the sensory test was 1. In addition, colorimetric color difference meter (Suga Test Instruments Co., Ltd., A
Yellowness is measured by UD-SCH-2) (JIS-Z-
8722. ) Was 1.3, and the white color was visually clear.

Comparative Example 1 Tertiary octyl peroxy neodecaneate 0.9
A roll sheet was obtained in the same manner as in Example 1 except that 0.86 kg of α-cumylperoxyneodecanate was used instead of 0 kg. Further, the yellowness was measured by a colorimetric color difference meter and found to be 1.1. The white color was clear by visual observation, but it was similar to phenol, which is considered to be due to the decomposition of α-cumylperoxyneodecanate during roll kneading. Had an offensive odor, and the odor intensity according to the sensory test was 4.

Example 2 Internal volume 7 m³ 2250 kg of water, the degree of saponification of 80
Partially saponified polyvinyl alcohol with an average degree of polymerization of 2000 in mol%
Coal 0.9kg, hydroxypropyl methyl cellulose
0.9 kg, tertiary octyl peroxy neode
Charge 24.0 kg of cane and vacuum pump the air inside.
2025 kg of vinyl chloride, carbon number 6,
Mixture of 8 and 10 α-olefins (Mitsubishi Chemical Industries, Ltd.)
Made by Dialen 610: C₆ 38 wt%, C₈ 34 wt
%, C_Ten225 kg of 28 wt%) was charged. Polymerization temperature
It was set at 45 ° C to allow the reaction to proceed and the internal pressure was 3 kg /
cm ²-Reaction continued until G pressure was reached. Not reacted after reaction
The monomer mixture is recovered, the copolymer slurry is discharged,
A copolymer dried and dehydrated was obtained as a product.

100 parts of the obtained copolymer, 20 parts of dioctyl phthalate, 0.3 part of dibutyltin mercaptide,
Add 0.3 parts of titanium oxide and roll it on a roll at 150 ℃.
The mixture was kneaded for 0 minutes and taken out as a 0.6 mm sheet. No offensive odor was felt during roll kneading, and the odor intensity according to the sensory test was 1. Further, the yellowness was measured by a colorimetric color difference meter and found to be 1.8, and the white color was visually clear.

Comparative Example 2 Tertiary octyl peroxy neodecaneate 24.
A roll sheet was obtained in the same manner as in Example 2 except that 22.5 kg of α-cumylperoxyneodecanate was used instead of 0 kg. Further, the yellowness was measured by a colorimetric color difference meter and found to be 2.0. The white color was visually clear, but it was similar to phenol, which is considered to be due to the decomposition of α-cumylperoxyneodecanate during roll kneading. Had an offensive odor, and the odor intensity according to the sensory test was 4.

[0023]

INDUSTRIAL APPLICABILITY The vinyl chloride polymers obtained by using the catalyst system of the present invention are suitable not only for general processed products but also for the food field because they have good hue and no odor during processing. It can be used, and it is industrially superior because it can maintain a good working environment with no offensive odor.

Claims (1)

[Claims] 1. A good hue obtained by using tertiary octyl peroxyneodecanate as a polymerization catalyst in aqueous suspension polymerization of vinyl chloride or a mixture of vinyl chloride and a monomer copolymerizable therewith. And vinyl chloride polymers with no odor.