JPH0328250A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition excellent in heat resistance, fluidity, heat stability, etc., and desirable for a heat-resistant pipe, a heat-resistant container, etc., by mixing a vinyl chloride/N-substituted maleimide copolymer with a dialkyltin sulfide compound. CONSTITUTION:A copolymer comprising 40-99wt.% vinyl chloride units, 50-1wt.% N-substituted maleimide units (e.g. N-phenylmaleimide) and 10-0wt.% structural units of another monomer (e.g. ethylene) copolymerizable with vinyl chloride or of a polymer onto which vinyl chloride can be grafted (e.g. ethylene/vinyl acetate copolymer) is produced. This copolymer is mixed with a dialkyltin sulfide compound (e.g. diethyltin sulfide or dibutyltin sulfide) to produce a vinyl chloride resin composition. The amount of the sulfide added is suitably about 1-5 pts.wt. per 100 pts.wt. copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vinyl chloride resin composition with excellent thermal stability.

(Prior art) Vinyl chloride resin has excellent physical properties such as mechanical strength, weather resistance, chemical resistance, and self-extinguishing properties, and is widely used for pipes, plates, films, sheets, containers, etc. The temperature is low and the heat deformation resistance is poor.

Hard vinyl chloride resins generally undergo thermal deformation at temperatures of 70 to 80°C, so they cannot be used at temperatures higher than that.

Endurance #! Various methods have been used to improve the deformability of the body. Although this copolymer has improved heat resistance and excellent fluidity, it has the disadvantage of poor thermal stability and easy dehydrochlorination during hot molding.

In addition, in order to improve the thermal stability, organotin stabilizers,
It is disclosed in JP-A-63-210154 and JP-A-63-309 that lead-based stabilizers, biolite compounds, etc. are added.
Although it is described in Japanese Patent No. 549, the thermal stability is still insufficient.

(Problems to be solved by Hatsuo) In view of the above-mentioned drawbacks, the purpose of the present invention is to provide a vinyl chloride-N-substituted maleimide copolymer that has excellent heat resistance, fluidity, etc., and excellent thermal stability. Vinyl chloride m fat #1
The purpose is to provide something.

(Means for solving problem a) The copolymer used in the present invention has vinyl chloride structural units, N
It consists of a monosubstituted maleimide structural unit and another monomer copolymerizable with vinyl chloride, or a polymer structural unit that can be graft-polymerized with vinyl chloride (hereinafter referred to as "third structural unit").

The N-substituted maleimide forming the above N-substituted maleimide structural unit is a compound represented by general formula (I).

In the formula, Rt-t is preferably an aliphatic group, a ring group, or an aromatic group having 3 to 20 carbon atoms, such as N-methylmaleimide, N-n-probylmaleimide, N-isopropylmaleimide, N-n -butylmaleimide, N-ter
t-butyl maleide. N-n-hexylmaleimide, N
-Cyclohexylmaleimide. N-7 enylmaleimide, N-2-chlorophenylmaleimide, N-2-methyI
lefuenilmarefmiF,N-2-ethylphenitvmaV
4mide, N 2,6-dichlorophenylmide,
N-2,6-dimethyl7enylmaleimide, N-penzylmaleimide, N-(2-chlorobenzyl)maleimide, N-(2-/tilpezyl)maleimide, N-naphthylmaleimide, etc. It will be done.

Examples of other monomers copolymerizable with vinyl chloride forming the third structural unit include α-olefins such as ethylene and propylene. Vinyl esters such as vinyl acetate, vinyl ethers such as butyl vinyl ether, cetyl vinyl ether, phenyl vinyl ether, and methyl acrylate. Acrylic acid esters such as ethyl acrylate, methyl methacrylate. ethyl methacrylate,
Methacrylic acid esters such as phenyl methacrylate,
Aromatic vinyls such as styrene, vinyl cyanides such as acrylonitrile and methacrylonitrile. Vinylidene chloride. Vinyl halides such as vinyl fluoride. Examples include unsaturated dicarboxylic acid esters such as maleic acid dimethyl ester and hexamalic acid dimethyl ester, unsaturated dicarboxylic acid anhydrides such as maleic anhydride, and two or more of these may be used in combination.

In addition, other polymers in which vinyl chloride forming the third structural unit has a rectangular shape include, for example, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid ester copolymer, ABSI1 resin, MBSm resin. , chlorinated polyethylene, chlorosulfonated polyethylene, polycrethane, butyl rubber. Examples include acrylic rubber, and these are 2a [
The above may be used in combination.

, ll1-polymer consists of a pinyl chloride structural unit, an N-substituted maleimide structural unit, and a tertiary structural unit, but when the ratio of N-substituted maleimide structural units becomes small, the bear resistance does not improve, and many If this happens, the impact resistance, processability, etc. will deteriorate, so the amount is 1 to 50% by weight, preferably 5 to 40% by weight, in the copolymer. In addition, as the ratio of the third structural unit increases, the inherent physical properties of the vinyl chloride resin deteriorate, so the ratio of the third structural unit is O to 10% by weight. Therefore, the ratio of the vinyl chloride structural unit is #i40.
~99% by weight.

The number average molecular weight (as measured by GPC) of the copolymer is preferably from 20,000 to 100,000, since mechanical strength decreases when it becomes small, and fluidity decreases when it increases.

Any method may be used to produce the above-mentioned copolymer, for example, a known suspension polymerization method, emulsion polymerization method, or solution polymerization method that uses a radical polymerization initiator and is commonly carried out in the polymerization of vinyl chloride. , bulk polymerization method, etc. The suspension polymerization method is preferably employed because the obtained copolymer is relatively free of impurities and the manufacturing cost is relatively low.

In the Ml5 polymerization method, part 011 is used as a suspension stabilizer.
Il-vinyl alcohol, cellulose derivatives, etc. are used, and as radical polymerization initiators, penzoylnot-t-oxide, diracloylnot-t-oxide, (e
Organic peroxides such as rt-butylperoxyneodacanoate are preferably used. The N-substituted maleimide may be added all at once into the polymerization vessel before the start of polymerization, or the entire amount may be added in portions or continuously during polymerization.

In particular, N whose copolymerizability ratio with vinyl chloride is significantly different
When using an N-mono-substituted maleimide such as -7 enylmaleimide, it is preferable to add the entire amount in portions during polymerization or to add it continuously because heat resistance is further improved. In this case, the N-substituted maleimide is preferably dissolved in an organic solvent such as acetone or methanol, or dispersed in water. And the polymerization temperature is generally 30 to 9
The polymerization time is generally 2 to 20 hours at 0°C.

The first invention of the present invention consists of the above copolymer and a dialkyltin sulfide compound, and the dialkyltin sulfide compound is a compound represented by general formula (II).

R/ R/ In the formula, R' is an alkyl group, preferably an alkyl group having 1 to 8 carbon atoms, such as diethyltin sulfide, diptyl pan sulfide, dioctyltin sulfide, and the like.

If the amount of the dialkyl pot sulfide compound added is small, the effect of improving thermal stability will be reduced, and if it is too large, the heat distortion temperature will be lowered, so it is recommended to add 1 to 5 parts by weight per 100 parts by weight of the copolymer. preferable. Further, the dialkyl pot sulfide compound may be used in combination with an organotin stabilizer such as dialkyltin dilacrate, dialkyltin malate, dialkyltin mercapto, or the like.

The second invention of the present invention is a vinyl chloride-based ellipsoid composition comprising the above-mentioned copolymer, an organic IIA-based stabilizer, and an epoxy compound having an epoxy equivalent of 400 or less.

Any conventionally known organic tin stabilizer can be used, but those with a tin content of 5 to 40 in the molecule are preferred, such as t#i digtyltin diocrate, diptyltin distearate, dioctyltin dilacrate, tripendyl Examples include tin lacrate, diptylated nabe malate, dimethyltin mercapto, diptylated tin mercapto, and the above-mentioned dialkyltin sulfide compounds are also included.

If the amount of organic M-based stabilizer added is small, the effect of improving thermal stability will be reduced, and if it is too large, the heat distortion temperature will be lowered, so it is recommended to add 1 to 5 parts by weight per 100 parts by weight of the copolymer. preferable.

As the epoxy equivalent of the above epoxy compound increases, the effect of improving thermal stability decreases, so those with a molecular weight of 400 or less are used. For example, bisphenol A glycidyl ether, epoxidized putadiene, triglycidyl isocyanate, glycidyl methacrylate Examples include meth)acrylate and copolymers with styrene.

If the amount of the epoxy compound added is small, the effect of improving thermal stability will be reduced, and if it is too large, the heat distortion temperature will be lowered and the epoxy compound will easily bleed. It is preferable to add 1 to 10 parts by weight, more preferably 0.1 to 10 parts by weight. It is 5 to 5 parts by weight.

The structure rL of the vinyl chloride resin composition of the present invention is as described above, but further contains calcium stearate, zinc stearate, palicum stearate, cadmicum stearate, which are used as stabilizers for vinyl chloride resin. Metal soaps such as lead stearate, dibasic sulfates, dibasic lead stearate, inorganic stabilizers such as hydroxide and silicate, lubricants, pigments, fillers, impact modifiers, and processing aids. UV absorbers, ultraviolet absorbers, etc. may be added.

(Example) Next, examples of the present invention will be described.

Examples 1 to 12, Comparative Examples 1 to 7 Predetermined amounts of copolymers shown in Tables 1 and 2, stabilizers, and ester lubricants (manufactured by Kao Corporation, KAO-wax
220) 3 parts by weight of the blend was mixed at 100°C for 3 minutes and mixed with a roll at 190°C for 3 minutes to obtain a sheet. The obtained sheet was supplied to a gear open at 190° C., and the time for blackening in the case (aging blackening time) was measured. Also, press the obtained sheet! ．． It was fed into a molding machine and pressed for 5 minutes at 190° C. and 75 kg/m to obtain a molded plate with a thickness of 6.4 times. The heat distortion temperature (HDT) of the obtained molded plate was measured in accordance with ASTM 0648. The results obtained are shown in Tables 1 and 2.

Table 3 shows the copolymer composition and weight average molecular weight determined by GPC of the copolymers used.

Table 1 No. 3 decline Can be used for

Claims (1)

[Scope of Claims] 1. 40 to 99% by weight of vinyl chloride structural units, 50 to 1% by weight of N-substituted maleimide structural units, and other monomers copolymerizable with vinyl chloride or graft polymerizable with vinyl chloride. A vinyl chloride resin composition comprising a copolymer comprising 10 to 0% by weight of polymer constitutional units and a dialkyltin sulfide compound. 2. 40 to 99% by weight of vinyl chloride structural units, 50 to 1% by weight of N-substituted maleimide structural units, and 10 to 10% of other monomers copolymerizable with vinyl chloride or polymeric structural units to which vinyl chloride can be graft-polymerized. 1. A vinyl chloride resin composition comprising a copolymer of 0% by weight, an organotin stabilizer, and an epoxy compound having an epoxy equivalent of 400 or less.