JPS6239609A - Production of vinyl chloride based resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having remarkably improved thermal stability without losing the antistatic effect even by washing treatment with water, etc., by graft copolymerizing a vinyl chloride resin with a specific aminoalkyl acrylate in a specific proportion. CONSTITUTION:0.2-25pts.wt. salt of an aminoalkyl acrylate expressed by the formula (R1 is H or methyl; R2 and R3 are H or 1-4C alkyl; n is an integer 1-4) is graft copolymerized with 100pts.wt. vinyl chloride resin within 30-100 deg.C temperature range, preferably in the presence of a radical polymerization initiator by the suspension polymerization method to afford the aimed resin. The above-mentioned vinyl chloride resin as preferably a vinyl chloride sole resin obtained by the aqueous suspension polymerization method and having 800-1,500 polymerization degree. For example, a salt, etc., obtained by reacting aminomethyl acrylate with methyl chloride is used as the salt of the compound expressed by the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a vinyl chloride resin with excellent chargeability, which is obtained by graft copolymerizing aminoalkyl acrylate #plate onto a vinyl chloride resin.

[Conventional technology]

Although vinyl chloride resin is a useful resin with extremely excellent properties as a so-called general-purpose resin, it has the drawback of being easily charged with static electricity, which is one of the general characteristics of plastics. Many methods have been proposed to improve the charging properties of vinyl chloride resin. A commonly used method is to add a compound having a polar group that is effective in preventing static electricity during processing of vinyl chloride resin, or to dilute it with a solvent and apply it to the surface of a molded product. Examples of compounds used for this purpose include nonionic, anionic, and cationic surfactants, and cationic surfactants having an amine group are particularly effective and are therefore widely used. Although methods such as adding such surfactants during processing of vinyl chloride resin or coating them on the surface of molded products are effective in preventing static electricity, the effect is temporary and the effect is not sustainable.

In other words, as long as the surfactant exists on the surface of the molded product, the antistatic effect is exhibited, so if the surface concentration decreases due to long-term use of the molded product, washing with water, etc., the antistatic effect will no longer be achieved. will no longer be recognized.

As described above, methods for preventing static electricity by adding or coating surfactants are extremely unsatisfactory in terms of sustainability and permanence of the antistatic effect.

For these reasons, an attempt has been made to copolymerize vinyl chloride with a comonomer having a polar group that is effective in preventing static electricity, thereby imparting permanent antistatic properties to vinyl chloride. In this case, a comonomer having an amine group is also considered to be effective in preventing static electricity, and a method has been proposed in which aminoalkyl acrylate is copolymerized with vinyl chloride. However, although it is recognized that this method is effective in preventing static electricity, the thermal stability of the vinyl chloride resin deteriorates significantly, making it impossible to obtain a copolymer that can be put to practical use. or,
When aminoalkyl acrylate was copolymerized with a salt obtained by reacting with an acid and vinyl chloride, the thermal stability of the resulting copolymer was improved to some extent, but it was still not sufficient.

[Problems to be solved by the present invention]

An object of the present invention is to provide a method for producing a vinyl chloride resin that does not lose its antistatic effect even after washing with water and has significantly excellent thermal stability.

[Means for solving problems]

The present inventors conducted extensive studies to achieve the above object, and finally arrived at the present invention.

That is, the present invention provides 100 parts by weight of vinyl chloride resin with the general formula (R is hydrogen or a methyl group, R2 and R3
is hydrogen or an alkyl group having 1 to 1 carbon atoms.

Moreover, n is an integer of 1-4. ) Aminoalkyl acrylate salt 0.2-2
This is a method for producing a vinyl chloride resin having excellent antistatic properties and thermal stability, which comprises graft copolymerizing 5 parts by weight.

The vinyl chloride resin to be the backbone polymer used in the present invention is a vinyl chloride sole resin obtained by homopolymerization of vinyl chloride, a copolymer resin with other monomers copolymerizable with vinyl chloride, or a vinyl chloride resin obtained by homopolymerization of vinyl chloride, Although graft copolymer resins of vinyl and other resins are included, vinyl chloride sole resins obtained by homopolymerization of vinyl chloride are practically preferred. The degree of polymerization of the vinyl chloride resin that should become the backbone polymer is 500 to 50.
00 is appropriate, and preferably 800-1500.

Moreover, it may be produced by any method such as solution polymerization, bulk polymerization, aqueous suspension polymerization, or aqueous emulsion polymerization.

In general, preference is given to aqueous suspension polymerization.

The aminoalkyl acrylate used in the present invention has the general formula % (where R is hydrogen or a methyl group, R2 and R3 are hydrogen or an alkyl group having 1 to 4 carbon atoms, and n
is an integer from 1 to 4. ) is a compound represented by Specifically, aminomethyl acrylate, aminoethyl acrylate, amino normal propyl acrylate, amino normal butyl acrylate, N-methylaminoethyl acrylate, N-ethylaminoethyl acrylate, N-ethylaminoisobutyl acrylate, N-tertiary-bunal Aminoethyl acrylate, N, N-
Dimethylaminoethyl acrylate, N,N-dimethylamino normal propyl acrylate, N,N-dimethylaminoisopropyl acrylate, N,N-dimethylamino normal butyl acrylate, N,N-diethylamine ethyl acrylate, N,N-diisopropylaminoethyl Aminoalkyl esters of acrylic acid such as acrylate, N,N-dinormal aminoethyl acrylate, N-methyl-N-ethylaminoethyl acrylate, N-methyl-N-n-normalbutylaminoethyl acrylate, and corresponding esters of methacrylic acid class is shown.

In the present invention, the above-mentioned aminoalkyl acrylates are used after being reacted with alkylene oxide or after being made into a salt with perchloric acid, alkyl chloride, dialkyl sulfuric acid, etc. without being reacted.

Examples of the alkyl chloride include methyl chloride, ethyl chloride, normal propyl chloride, isopropyl chloride, normal butyl chloride, and 2-ethyl hequinyl chloride.

Examples of the dialkyl sulfuric acid include dimethyl sulfate, diethyl sulfate, di-n-propyl sulfate, di-n-butyl sulfate, diisobutyl sulfate, di-2-ethylhexyl sulfate, and the like.

When alkylene oxide is reacted to form a salt, examples of the alkylene oxide that can be used include ethylene oxide, propylene oxide, and butylene oxide, with ethylene oxide being particularly preferred. In addition, as a method for producing salt by reacting alkylene oxide,
Known methods can be applied. For example, alkylene oxide is added to a solution of aminoalkyl acrylate in a lower alcohol such as methyl alcohol, ethyl alcohol, or isopropyl alcohol in the presence of water to form ammonium hydroxide, and then perchloric acid, alkyl chloride, dialkyl Neutralize with sulfuric acid. Further, when using an aminoalkyl acrylate having hydrogen in the amine group or perchloric acid as the acid component used for neutralization, it is also possible to neutralize it first and then allow the alkylene oxide to act on it.

In addition, even in the case of deviation, 30 to 60°C is appropriate as the temperature at which the alkylene oxide is reacted.

In the present invention, the amount of these aminoalkyl acrylate salts used is from 0.2 to 0.02 to 100 parts by weight of vinyl chloride resin.
The amount is 20 parts by weight, preferably 0.5 to 15 parts by weight. 0.
If it is less than 2 parts by weight, the antistatic properties of the resulting resin will be insufficient, and if it exceeds 20 parts by weight, the antistatic properties of the resin obtained will not be improved more than that and graft copolymerization will not be possible. It becomes difficult.

The graft copolymerization reaction in the present invention is advantageously carried out by a radical polymerization method, and the radical polymerization initiators used for this purpose include lauroyl peroxide, tert-butyl peroxybivalate, diisopropyl peroxydicarbonate, Organic peroxides such as dioctyl peroxydicarbonate, oil-soluble polymerization initiators such as azo compounds such as 2,2'-azobisisobutylonitrinope, 2,2'-azobis-2,4-dimethyltoneronitrile, and water-soluble polymerization initiators such as potassium persulfate and ammonium persulfate. The amount of these polymerization initiators used is 0.0 per 100 parts by weight of vinyl chloride resin.
The amount is preferably 0.05 to 1.0 parts by weight.

Alternatively, as another means, graft copolymerization by radiation irradiation may be performed.

Examples of polymerization methods include aqueous suspension polymerization, aqueous emulsion polymerization, solution polymerization, and solventless polymerization, with aqueous suspension polymerization being generally advantageous.

When carrying out aqueous suspension polymerization, the amount of water used is 1.5% of the amount of vinyl chloride resin that is the backbone polymer. ~5 times by weight, preferably 1 to 3 times by weight is appropriate.

In this case, it is preferred to use suspension stabilizers conventionally used in the polymerization of vinyl chloride. For example, polyvinyl alcohol and its partially saponified products, methylcellulose,
Examples include starch and gelatin, which may be used alone or in combination. The amount added is suitably 0.01 to 1.0 parts by weight per 100 parts by weight of the vinyl chloride resin.

Furthermore, a chain transfer agent used in conventional methods for polymerizing vinyl monomers may be added in an amount of 0.001 to 10 parts by weight per 100 parts by weight of vinyl chloride resin.

For the purpose of increasing the grafting efficiency, compounds having a swelling effect on the vinyl chloride resin, such as ketones, may be freely added.

It is appropriate to carry out the reaction at a temperature in the range of 30 to 100°C.
If it is less than 0°C, the reaction rate of graft copolymerization will be slow, and if it exceeds 100°C, the vinyl chloride resin will deteriorate, so the deviation in °C is also not preferred.

The reaction time is determined by the type and amount of the polymerization initiator used and the reaction temperature, but in the present invention, it is usually 3 to 1
It is 0 hours.

After the graft polymerization is completed, if necessary, unreacted upper polymers are collected, dehydrated and dried to obtain the resin of the present invention.

In addition, after aqueous suspension polymerization of vinyl chloride resin, which is the backbone polymer, unreacted vinyl chloride monomer is recovered, and then an aminoalkyl acrylate salt is added to the resulting vinyl chloride resin suspension to initiate polymerization if necessary. It is also possible to perform graft copolymerization by adding additives, suspension stabilizers, and other polymerization aids.

The vinyl chloride resin obtained by the method of the present invention can be prepared by using conventional stabilizers for vinyl chloride resins, such as lead white, lead-based inorganic stabilizers such as tribasic lead sulfate, fatty acids calcium, zinc, barium, cadmium, etc. It is stabilized by metal soaps such as lead salts, organic tin compounds, etc., and is used in practical use by adding plasticizers, lubricants, pigments, ultraviolet absorbers, etc. as necessary.

The vinyl chloride resin obtained by the present invention is molded by press molding, calendar molding, extrusion molding, injection molding, etc., which are molding methods applied to vinyl chloride resin. The obtained molded product has permanent antistatic properties that do not lose its effectiveness even after long-term use or washing with water.

〔Example〕

The present invention will be explained below with reference to Examples.

Note that the parts shown in Examples and Comparative Examples are M parts.

Example 1 100 parts of a vinyl chloride homopolymer with a degree of polymerization of 1050 obtained by suspension polymerization, 10 parts of a salt obtained by reacting dimethylamine ethyl methacrylate with ethylene oxide and methyl chloride, and 0.05 parts of partially saponified polyvinyl alcohol.
1 part, 0.3 parts of 2,2'-azobisisobutyronitrile were charged into an autoclave together with 300 parts of pure water, and after replacing the air inside with nitrogen, the temperature was raised to 60°C to start the reaction. . After reacting at 60°C for 8 hours, the contents were taken out from the autoclave and dehydrated and dried to obtain a powdered vinyl chloride resin.

A press sheet was prepared from the obtained resin by the method described below, and the frictional charging voltage and thermal stability were measured. The results are shown in the table.

Example 2 A vinyl chloride resin was obtained in the same manner as in Example 1, except that 10 parts of a salt of dimethylaminoethyl acrylate obtained by using propylene oxide instead of ethylene oxide was used as the aminoalkyl acrylate salt, and a press sheet was prepared. The frictional charging voltage and thermal stability were measured. The results are shown in the table.

Example 3 Example 1 except that 15 parts of the salt of dimethylaminoethyl acrylate obtained by using ethyl chloride instead of methyl chloride was used as the salt of aminoalkyl acrylate.
A vinyl chloride resin was obtained in the same manner as above, a press sheet was prepared, and the frictional charging voltage and thermal stability were measured. The results are shown in the table.

Example 4 A vinyl chloride resin was obtained in the same manner as in Example 1, except that 5 parts of the salt of dimethylaminoethyl acrylate obtained by using diethyl sulfate instead of methyl chloride was used as the salt of aminoalkyl acrylate, and a press sheet was prepared. were prepared and their frictional charging voltage and thermal stability were measured. The results are shown in the table.

Example 5 A vinyl chloride resin was obtained in the same manner as in Example 1, except that 10 parts of a salt obtained by reacting dimethylaminoethyl acrylate with methyl chloride was used as the aminoalkyl acrylate salt, and a press sheet was prepared. Frictional charging voltage and thermal stability were measured. The results are shown in the table.

Example 6 A vinyl chloride resin was obtained in the same manner as in Example 1 except that 5 parts of perchlorate of dimethylaminoethyl methacrylate was used as the aminoalkyl acrylate salt, a press sheet was prepared, and the frictional charging voltage and heat Stability was measured.

The results are shown in the table.

Comparative Example 1 A vinyl chloride resin was obtained by following Example 1 except that 8 parts of dimethylaminoethyl acrylate was used instead of the aminoalkyl acrylate salt, and a press sheet was prepared to improve the frictional charging voltage and thermal stability. It was measured. The results are shown in the table.

In this comparative example, the frictional charging voltage is equivalent to that of the present invention, but the thermal stability is inferior.

Comparative Example 2 In an autoclave equipped with a stirring blade, 300 parts of deionized water, 7.5 parts of a salt obtained by reacting dimethylamine ethyl methacrylate with ethylene oxide and methyl chloride, 0.23 parts of hydroxypropyl methylcellulose, and 2.2 parts of hydroxypropyl methyl cellulose were added. After adding 0.15 parts of '-azobisisobutyronitrile and replacing the air inside with nitrogen, vinyl chloride 14
A copolymerization reaction was carried out at 63°C with vigorous stirring.

After 15 hours, the internal pressure of the polymerization machine decreased to 6.5 kg/i, so the copolymerization reaction was stopped. After removing unreacted vinyl chloride monomer, the slurry was dehydrated and dried by a conventional method to obtain a white powder, a pressed sheet was prepared, and the frictional charging voltage and thermal stability were measured. The results are shown in the table.

The product of this comparative example has excellent frictional charging voltage and thermal stability, but its thermal stability is slightly inferior to that of the present invention.

Comparative Example 3 An attempt was made to obtain a vinyl chloride resin in the same manner as in Example 1 except that the amount of aminoalkyl acrylate salt used was increased to 30 parts by weight, but the reaction did not proceed well (the reaction did not proceed and the reaction was stopped midway). did.

Comparative Example 4 A vinyl chloride resin was obtained in the same manner as in Example 1, except that the amount of the aminoalkyl acrylate salt used was reduced to 0.1 parts by weight, a press sheet was prepared, and the frictional charging voltage and thermal stability were measured. The results are shown in the table.

In this comparative example, the amount of aminoalkyl acrylate salt was insufficient, and the antistatic properties were not very good (゛.

Comparative Example 5 The same treatment as in Example 1 was performed except that the aminoalkyl acrylate salt was not used. Vinyl chloride resin was recovered.

A pressed sheet was prepared from the recovered resin at 10°C, and the frictional charging voltage and thermal stability were measured.

The results are shown in the table.

Measurement of frictional charging voltage and thermal stability (1) Preparation of sample: 1 part of organotin stabilizer (trade name: ADVASTAB T-17MJ manufactured by Toa Rika) and 0.5 part of stearic acid were added to 100 parts of vinyl chloride resin. After mixing well, the mixture was press-molded at 150°C to produce a 1 mm thick press sheet.

(2) Charging voltage: Using a rotary static tester (manufactured by Kyowa Shokai), the charging voltage is measured after 3 minutes of rubbing with cotton cloth at 20° C. and 60% relative humidity.

The measurements were taken twice: immediately after the press sheet was created, and once after it had been immersed in running water for two days and nights.

(3) Thermal stability (conc;, red thermal stability): JI
According to SK-6723.

〔Effect of the invention〕

The vinyl chloride resin obtained by the method of the present invention has good antistatic properties and good thermal stability, and is of great industrial value.

Claims (1)

[Claims] 1. 100 parts by weight of vinyl chloride resin has a general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (Here, R_1 is hydrogen or a methyl group, R_2 and R
_3 is hydrogen or an alkyl group having 1 to 4 carbon atoms. Moreover, n is an integer of 1-4. ) Aminoalkyl acrylate salt 0.2-2
A method for producing a vinyl chloride resin having excellent antistatic properties and thermal stability, the method comprising graft copolymerizing 5 parts by weight of a vinyl chloride resin.