JP3107165B2 - Vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride elastomer suitable for applications requiring rubber elasticity.

[0002]

2. Description of the Related Art Conventionally, methods for improving the rubber elasticity of vinyl chloride resins include, for example, organic peroxides such as benzoyl peroxide, dicumyl peroxide and t-butyl peroxide, for example, 1,4-tetramethylenediamine. , 1,
6-Hexamethylenediamine and other diamine-based compounds, for example, sulfur, tetramethyl turum disulfide, triazine dithiol and other sulfur-based compounds such as cross-linking vinyl chloride resin, diallyl phthalate, cross-linkable polyurethane or epoxy resin component cross-linking method A method of blending a crosslinked vinyl chloride resin or a crosslinked polyurethane having good compatibility with the vinyl chloride resin, which has been previously crosslinked at the time of polymerization, or a crosslinked polyurethane, into the vinyl chloride resin, using a vinyl chloride resin having a reactive group such as a hydroxyl group. There is a method of forming a crosslinked body with diisocyanate or the like.

In these methods, when a vinyl chloride resin is cross-linked, a rubber-like elastic body can be easily obtained. However, on the other hand, the problems are (1) poor thermal stability and easy coloring. (2) Odor remains due to cross-linking agent residue (3)
When the degree of crosslinking is increased, there is a problem that a large amount of a plasticizer is required to obtain a predetermined hardness.

When a reactive plasticizer is used, it is often a radical reaction system, so that the same problem as described above occurs.

[0005] When a crosslinked vinyl chloride resin or crosslinked NBR is blended with a vinyl chloride resin, (1) physical properties such as tensile strength and elongation are significantly reduced due to their dispersibility in the vinyl chloride resin. 2) A large amount of plasticizer is required to adjust the hardness. (3) Decrease in rebound resilience. (4) Addition of a large amount deteriorates moldability. (5) Deterioration when used at high temperatures or in places exposed to sunlight for a long time. There is a problem that the initial performance cannot be maintained.

Further, in a method of using a vinyl chloride resin having a reactive group such as a hydroxyl group to form a crosslinked product with diisocyanate or the like, it is difficult to obtain desired elasticity due to poor reactivity.

In recent years, a composite of a vinyl chloride resin and a polyurethane has attracted attention, and various methods have been proposed. For example, a method in which a polyurethane is dissolved in a vinyl chloride monomer (VCM) and a composite of the vinyl chloride resin and the polyurethane is obtained by polymerization of the VCM, and a hydroxyl group-containing vinyl chloride resin is produced by polymerization of the VCM in the presence of a polyol. There is a method obtained by a urethanization reaction, a method obtained by impregnating a vinyl chloride resin with a polyol, an isocyanate, a catalyst and the like, and reacting.

However, the composite of a vinyl chloride resin and polyurethane obtained by these methods has poor rubber elasticity and is not suitable for applications requiring rubber elasticity. In such a method for producing a composite, when a urethane crosslinked product is produced using triisocyanate, the processability becomes poor.

Further, as a generally used method of combining a vinyl chloride resin and polyurethane, there is a method in which a vinyl chloride resin and a polyurethane elastomer having high elasticity are polymer-blended in a roll or a Banbury mixer.

[0010] The composite obtained by this method is excellent in rebound resilience but inferior in compression set, and is therefore required to be improved.

As a result of recent studies, we have found that as a method of solving such a problem, a vinyl chloride resin, a polymer polyol having two or more hydroxyl groups and having a molecular weight of 300 to 10,000 and three isocyanate groups are used. A vinyl chloride-based resin composition obtained by heating and melting a compound having the above-mentioned properties under shearing force, wherein tetrahydrofuran (T
HF) A vinyl chloride resin composition having an insoluble content of 5 to 55% by weight was proposed.

[0012]

With this composition, the problems of the conventional vinyl chloride elastomer were solved, and a sufficient rubber elastic body was obtained. In addition, more advanced urethane crosslinks must be produced.

However, if a THF-insoluble content is increased to produce a highly crosslinked urethane product, the composition will not be plasticized.

On the other hand, even with the composition having the above-mentioned THF-insoluble matter, the surface smoothness of the molded product was sometimes poor.

[0015]

Means for Solving the Problems In view of the above-mentioned situation, the present inventors have developed a vinyl chloride-based elastomer which is excellent in gelling and melting property when a more advanced urethane crosslinked product is produced.
The results were studied over, leading to the completion of the present invention.

That is, the present invention provides a vinyl chloride resin 100
0.1 to 30 parts by weight of a methyl methacrylate-alkyl acrylate copolymer, 10 to 180 parts by weight of a polymer polyol having 2 or more hydroxyl groups and a molecular weight of 300 to 10,000, and isocyanate group 3 based on parts by weight. A vinyl chloride-based elastomer obtained by heat-melting and mixing a compound having at least one isocyanate group with a hydroxyl group under a shearing force in a range of 0.3 to 1.3,
In which the elastomer in tetrahydrofuran (THF) insoluble content regarding <br/> vinyl chloride elastomer from 5 to 60 wt%.

Hereinafter, the present invention will be described in detail. The vinyl chloride resin used in the present invention may be one obtained by a commonly used polymerization method. For example, there are a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and an emulsion polymerization method.

In the present invention, the vinyl chloride resin is
A vinyl chloride homopolymer and a copolymerized vinyl chloride resin with a monomer copolymerizable with a vinyl chloride monomer. Also,
The polymerization degree of the vinyl chloride resin is preferably 800 to 8,000,
Those with a range of 1,000 to 5,000 are used.

Examples of monomers copolymerizable with the vinyl chloride monomer include ethylene, propylene, butene, pentene-1, butadiene, styrene, α-methylstyrene,
Acrylonitrile, vinylidene chloride, vinylidene cyanide, alkyl vinyl ethers, vinyl carboxylate esters, aryl ethers, dialkyl maleates, fumarate esters, N-vinyl pyrrolidone, vinyl pyridine, vinyl silanes, alkyl acrylate esters, methacrylic acid Acid alkyl esters and the like.

Further, the vinyl chloride resin may be a graft polymer such as an ethylene-vinyl acetate-vinyl chloride graft polymer and a vinyl chloride-urethane copolymer. However, the vinyl chloride resin is not limited to these. A crosslinked vinyl chloride resin obtained by adding a divinyl compound such as divinylbenzene during the polymerization of these polymers is also used.

The crosslinked vinyl chloride resin has a tetrahydrofuran (THF) insoluble content in the range of 0.1 to 25% by weight in weight percentage, and is used alone or in a blend with an uncrosslinked vinyl chloride resin.

The polymer polyol used in the present invention is:
It has two or more hydroxyl groups and a molecular weight of 300 to 10,000, preferably 1,000 to 5,000. Such a polymer polyol is, for example, a glycol having 5 or less repeating units obtained by ring-opening polymerization of an aliphatic dicarboxylic acid having 4 to 10 carbon atoms and an aliphatic glycol having 2 to 10 carbon atoms and / or an epoxy group. Can be obtained by condensation polymerization.

In the present invention, the molecular weight refers to a number average molecular weight, which can be measured by gel permeation chromatography (GPC) or the like.

The aliphatic glycol having 2 to 10 carbon atoms used for producing the polymer polyol includes, for example, 1,2-ethanediol, 1,2-propanediol, 1,4-butanediol, butenediol, 3 -Methyl-1,5-pentanediol, 1,6-hexanediol, 1,10-decamethylenediol, 2,5-dimethyl-2,5-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, etc. Is mentioned.

On the other hand, examples of the compound having an epoxy group include cyclic ethers such as ethylene oxide, propylene oxide and tetrahydrofuran (THF). Those obtained by subjecting these to ring-opening polymerization to form a glycol having a repeating unit of 5 or less are also suitably used as the glycol of the present invention. One or more of these are used.

Examples of the aliphatic dicarboxylic acid having 4 to 10 carbon atoms used in the production of the polymer polyol include succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and the like. More than seeds are used.

As such a polymer polyol,
It is marketed by Nippon Polyurethane Co., Ltd. under the trade name Nipporan.

The amount of polymer polyol, based on 100 parts by weight of a vinyl chloride resin, 10 to 180 parts by der
You . If the amount is less than 10 parts by weight, the rubber elasticity is not improved, and
If it exceeds 80 parts by weight, processing becomes impossible.

The compound having three or more isocyanate groups used in the present invention includes, for example, 2,4- and 2,6-tolylene diisocyanate, m- and p-phenylene diisocyanate, 1-chlorophenylene-2,4 -Diisocyanate, 1,5-naphthalenediisocyanate, methylenebisphenylene-4,4'-diisocyanate, m- and p-xylenediisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, isophorone diisocyanate, trimethyl Triisomer of diisocyanate such as hexamethylene diisocyanate, 1,6,11-undecane triisocyanate, lysine ester triisocyanate,
Examples include triisocyanates such as isocyanatemethyl-1,8-octamethyldiisocyanate and polyfunctional isocyanates such as polyphenylmethane polyisocyanate, and one or more of these are used. It is also possible to use the above diisocyanates in combination.

However, the number of moles of NCO groups of triisocyanate is 0.25 with respect to the number of moles of NCO groups of all isocyanates.
The above is desirable. If it is less than 0.25, sufficient performance cannot be exhibited due to insufficient crosslinking density.

The NCO / OH ratio is from 0.3 to 1.3.
If it is less than 0.3, even if only triisocyanate is used as the isocyanate, sufficient performance cannot be exhibited due to insufficient crosslinking density. If it exceeds 1.3, it cannot be processed.

The methyl methacrylate-alkyl acrylate copolymer used in the present invention may be one obtained by general emulsion polymerization. Examples thereof include JP-A-57-109812 and JP-A-57-109812.
The method may be performed as exemplified in 57-74347. The component ratio of the copolymer is 50 to 95% by weight of methyl methacrylate,
The alkyl acrylate is 5 to 50% by weight, and the molecular weight of the obtained copolymer is evaluated by, for example, the reduced viscosity at 25 ° C. of a solution obtained by dissolving 0.1 g of the copolymer in 100 cc of chloroform. It is said that the smaller the value, the lower the molecular weight and the better the dispersibility in the vinyl chloride resin, and conversely, the larger the value, the higher the molecular weight, which leads to rubber elasticity due to entanglement of molecular chains. The optimum value of the reduced viscosity of the methyl methacrylate-alkyl acrylate copolymer used in the present invention is 1 to 10.

The alkyl acrylate which can be used in the present invention means an alkyl acrylate having an alkyl group having 1 to 10 carbon atoms, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate. And the like, but are not limited to these. One or more of these are copolymerized with methyl methacrylate.

[0034] Such a methylated obtained methacrylate - amount of alkyl acrylate copolymer relative to 100 parts by weight of a vinyl chloride resin, 0.1 to 30 parts by weight
There is . If the amount is less than 0.1 part by weight, the gelling and melting properties of the vinyl chloride resin and the surface smoothness of the molded article cannot be improved. Is not preferred.

In particular, when a high degree of rubber elasticity is required and the degree of polymerization of the vinyl chloride resin used is high, and when the urethane crosslinked product weight fraction in the composition is high, the addition of this resin is
is important.

The use of the plasticizer in the present invention is not limited. Examples of the plasticizer that can be used in the present invention include di-n-butyl phthalate and di-2-phthalate.
Ethylhexyl (DOP), di-n-octyl phthalate, diisooctyl phthalate, octyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate,
Phthalate plasticizers such as di-2-ethylhexyl isophthalate, di-2-ethylhexyl adipate (DOA), di-n-decyl adipate, diisodecyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate, etc. Aliphatic ester plasticizers, trimellitic acid plasticizers such as trioctyl trimellitate and tridecyl trimellitate, pyromellitic acid plasticizers such as tetraoctyl pyromellitic acid, tributyl phosphate, and tri-2-phosphate Ethylhexyl, 2-ethylhexyl diphenyl phosphate, phosphate plasticizers such as tricresyl phosphate, epoxidized soybean oil, epoxy plasticizers such as epoxidized linseed oil, and condensation polymerization of adipic acid or sebacic acid with glycol. Examples of the obtained polymer plasticizer having an average molecular weight of 500 to 10,000 include one or more of these. 2 or more is used.

In preparing the elastomer of the present invention, a catalyst may be used. Although the reaction proceeds without using a catalyst, it is preferable to use a catalyst because a uniform reaction proceeds.

As such a catalyst, any catalyst used in a general urethane-forming reaction may be used, for example, amine catalysts such as triethylamine, triethylenediamine, N-methylmorpholine, tetramethyltin, tetraoctyltin, and the like. Examples include tin-based catalysts such as dimethyldioctyltin, triethyltin chloride, dibutyltin diacetate, and dibutyltin dilaurate.

In the present invention, a stabilizer can be added to the vinyl chloride resin. Examples of the stabilizer include metal soap-based stabilizers such as lead stearate, calcium stearate, barium stearate, zinc stearate, and cadmium stearate, and epoxy-based stabilizers such as epoxidized soybean oil and epoxidized linseed oil. No.

Further, if necessary, an ultraviolet absorber, an antioxidant, an antioxidant, a processing aid, a filler and the like which are usually used can also be blended. However, in the present invention,
If a tin-based stabilizer is used, it becomes a catalyst for hydrolysis of the ester-based polymer polyol.

The elastomer of the present invention is used, for example, in a kneader capable of shearing and melting a resin, such as a roll forming machine, a twin-screw kneader, an extruder, and a Banbury mixer.

More specifically, for example, taking a Banbury mixer as an example, first, a casing temperature of 100 to 200
At a temperature of ° C., a vinyl chloride resin and, if necessary, an ultraviolet absorber, an antioxidant, an antioxidant, a processing aid, a filler and the like which are usually used are added and mixed. 50 to 80 in advance
A polyol, a plasticizer, an isocyanate, and a catalyst kept at a temperature of ° C. are weighed and mixed, and charged from the inlet of a Banbury mixer. 100-200 ° C while applying shearing force
The mixture is further heated and mixed, and the vinyl chloride resin is melted and urethanized, and is taken out after 3 to 60 minutes. The thus obtained elastomer can be formed into a sheet by applying it to a roll forming machine.

The THF-insoluble content of the elastomer of the present invention is:
It needs to be 5 to 60% by weight. If the insoluble content is less than 5% by weight, sufficient compression set cannot be given, and
If it exceeds 0% by weight, molding becomes difficult.

The method for measuring the THF-insoluble content is as follows. In other words, roll sheets with a thickness of 1.0 ± 0.1 mm
Cut to 0-1.5mm square and weigh 1.0g. This is 300cc
And stirred with a stirrer in 200 ml THF for 2 hours. The sample swells with THF, but is filtered through a 300-mesh sieve, crushed with a glass rod or the like, and the filtrate is further stirred with a stirrer in 200 ml of THF for 4 hours. The solution is filtered through a filter paper that has been weighed in advance to separate insoluble components, the insoluble components and the filter paper are placed on a petri dish, dried in a 40 ° C. oven for 5 hours, and then weighed. The weight percentage of THF insoluble matter is determined from the weight of insoluble matter obtained by this method.

[0045]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Reference Example 1 Copolymerization of methyl methacrylate and n-butyl acrylate was carried out according to the method exemplified in JP-A-57-74347.
At this time, the composition ratio of the copolymer was methyl methacrylate.
The solution had a reduced viscosity at 25 ° C. of 90% and n-butyl acrylate of 10%, and a solution obtained by dissolving 0.1 g of the obtained copolymer in 100 cc of chloroform was 3.3.

Reference Example 2 In the same manner as in Reference Example 1, the amount of the chain transfer agent was reduced.
Copolymerization of methyl methacrylate and n-butyl acrylate was performed. At this time, the composition ratio of the copolymer was methyl methacrylate 90%, n-butyl acrylate 10%, and 0.1 g of the obtained copolymer was added to 100 cc of chloroform.
The reduced viscosity at 25 ° C of the solution when dissolved in was 7.6.

Example 1 A vinyl chloride resin (manufactured by Tosoh Corporation, trade name Ryulon E-2800, average polymerization degree 280) obtained by a suspension polymerization method in a Banbury mixer having an inner volume of 1700 cc and a casing temperature of 150 ° C.
0), 400 g of methyl methacrylate and n-butyl acrylate copolymer produced in Reference Example 1, 8 g of barium stearate and 4 g of zinc stearate as stabilizers.
g, manufactured by Nissan Ferro-Organic Chemical Co., Ltd. as an amine scavenger
6 g of brand name BP-331 was charged and stirred at a constant rotation speed.
Separately, 720 g of a polymer polyol (Nipporan 4067, trade name, manufactured by Nippon Polyurethane Co., Ltd., trade name: Nipporan 4067, number average molecular weight 2,000) preliminarily kept at 70 ° C. and 200 g of dibutyl phthalate (DBP) are mixed. Hexamethylene diisocyanate trimer (manufactured by Nippon Polyurethane Co., Ltd.
121 g (trade name: Coronate HX) (NCO / OH ratio = 1) 0.07 g of dibutyltin diurarate was charged as a catalyst, mixed for 1 minute, and then poured into the Banbury mixer inlet. The reaction and mixing time was 15 minutes.

After the completion of the reaction, the obtained composite was set on a roll forming machine to form a sheet, which was then press-molded so as to have a thickness of 12.70 ± 0.13 mm for JIS K6301 compression set.
Subsequently, the compression set (JIS K 6301) and the JIS A type hardness (JIS K 6301) of the obtained press plate were measured. Further T
The HF insoluble content weight% was measured.

Separately from this, a sheet was molded by extrusion of the product, and the surface smoothness of the appearance was visually observed and evaluated as follows. ：: Excellent ×: The surface is rough and the unevenness is severe and there is no luster The results are shown in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that the copolymer of methyl methacrylate and n-butyl acrylate was replaced with that prepared in Reference Example 2 to evaluate the same. Table 1 shows the results.

Example 3 A vinyl chloride resin having an average degree of polymerization of 4,200 obtained by the ordinary suspension polymerization method in the Banbury mixer used in Example 1
g, 10 g of a copolymer of methyl methacrylate and n-butyl acrylate produced in Reference Example 1, 10 g of barium stearate, 5 g of zinc stearate as a stabilizer, and a trade name of Nissan Ferro-Organic Chemical Co., Ltd. as an amine scavenger. BP-3
31 and 7.5 g were charged and stirred at a constant rotation speed. Separately, polymer polyol (Nipporan 4067, manufactured by Nippon Polyurethane Co., Ltd.
400g of number average molecular weight 2,000) and dibutyl phthalate (DB
P) was mixed with 500 g, and 67.2 g of hexamethylene diisocyanate trimer (trade name: Coronate HX, manufactured by Nippon Polyurethane Co., Ltd.) (NCO / OH ratio = 1) was charged with 0.04 g of dibutyltin diurarate as a catalyst. After mixing for 1 minute, the mixture was poured from the Banbury mixer inlet. Production and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

Example 4 In Example 3, Lulon E-280 was added to vinyl chloride resin.
Except for using 0, 500 g, and 500 g of di-2-ethylhexyl phthalate (DOP) as a plasticizer, all were produced and evaluated in the same manner as in Example 3. Table 1 shows the results.

Comparative Example 1 The procedure of Example 1 was repeated, except that the methyl methacrylate-n-butyl acrylate copolymer was not added. The resulting composition was a material that was not kneaded and difficult to mold.

Comparative Example 2 The procedure of Example 3 was repeated, except that the methyl methacrylate-n-butyl acrylate copolymer was not added, and the production was performed in the same manner as in Example 3, and evaluated. Table 1 shows the results.

[0056]

[Table 1]

[0057]

As is apparent from the above description, the rubber-elastic vinyl chloride elastomer obtained by the present invention.
The mer has excellent surface smoothness and is easy to mold. It is further characterized by high rebound resilience and low compression set.

Claims (1)

(57) [Claims] 1. A methyl methacrylate-alkyl acrylate copolymer containing 100 parts by weight of a vinyl chloride resin .
1 to 30 parts by weight , a polymer polyol 10 having 2 or more hydroxyl groups and having a molecular weight of 300 or more and 10,000 or less
To 180 parts by weight and a compound having three or more isocyanate groups in which the ratio of isocyanate groups to hydroxyl groups is 0.1%.
Under shear forces in the range of 3 to 1.3, a vinyl chloride-based elastomer obtained by heating and melting a mixture, a vinyl chloride elastomer tetrahydrofuran-insoluble matter of the elastomer is 5 to 60 wt%.