JPH0241349A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To obtain a vinyl chloride resin composition having excellent heat- resistance, weather-resistance, compression set property and moldability and suitable as hose, gasket, etc., by compounding specific amounts of a specific crosslinked rubbery copolymer and a specific antioxidant. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts.wt. of a vinyl chloride resin having a molecular weight of 600-4,000 with (B) 10-200 pts.wt. of a crosslinked rubbery copolymer composed of (B1) 5-20wt.% of butadiene and/or isoprene, (B2) 10-50wt.% of acrylonitile, (B3) 30-85wt.% of an alkyl (meth)acrylate and/or alkoxyalkyl (meth)acrylate and (B4) 0.1-5wt.% of a crosslinking monomer of formula I (R1 and R2 are H or methyl; R is -C6H4-, etc.) or formula II (R1 is H or methyl; R2 is hydrocarbon residue; n is 3-5) and further containing (B5) 0.1-5wt.% of an antioxidant of formula III (R, R1 and R2 are H or 1-4C alkyl).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vinyl chloride resin composition that has excellent heat resistance, weather resistance, compression set characteristics, mechanical strength, and moldability.

[Prior Art] It has long been known to improve the properties of vinyl chloride resin by mixing butadiene-acrylonitrile copolymer rubber (hereinafter NBR) with vinyl chloride resin. By increasing the amount of NBR added, a molded article having rubber elasticity can be obtained without going through a vulcanization process.

For this, JP-A-57-115342, JP-A-5
It is known that NBR containing a specific amount of gel content is even better, as seen in No. 7-187341 and others. However, when NBR is mixed with vinyl chloride resin, compression set characteristics, moldability, etc. are improved, but on the other hand,
There was a problem that heat resistance and weather resistance deteriorated.

If the butadiene moiety in NBR, which is the cause of this, is reduced, the acrylonitrile moiety will inevitably increase, and the glass transition temperature of the crosslinked rubbery polymer will increase, and the blend of vinyl chloride resin and plasticizer will increase. This is not preferable because the cold resistance of the material decreases.

An improvement to this would be to reduce the butadiene moiety and instead increase the acrylonitrile monomers, i.e., alkyl (meth)acrylates and / or using an alkoxyalkyl (meth)acrylate and further using a specific crosslinking monomer,
The use of crosslinked rubbery copolymers obtained by copolymerization with these is disclosed in JP-A-58-117209 and JP-A-60-6742.

On the other hand, in most of the recent markets for vinyl chloride resin compositions, mainly for automobiles, there has been a demand for higher heat resistance and weather resistance.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a vinyl chloride resin composition that satisfies these requirements for high heat resistance and weather resistance, and has good compression set properties and moldability. This is what we are trying to provide.

[Means for Solving the Problems] The present invention simultaneously realizes various required properties with a composition comprising a vinyl chloride resin, a specific crosslinked rubbery copolymer, and a specific anti-aging agent. Solve the above problems.

Until now, JP-A-58-117209, JP-A-60-6
742 with butadiene and/or isoprene 5-65
% by weight, a crosslinked rubbery copolymer consisting of 10 to 50% by weight of acrylonitrile, 5 to 80% by weight of alkyl (meth)acrylate and/or alkoxyalkyl (meth)acrylate, and 0.1 to 5.0% by weight of crosslinking monomer. A vinyl chloride resin composition that can be mixed with a vinyl chloride resin composition and has excellent heat resistance and weather resistance is disclosed. However, it has become clear that the crosslinked rubbery copolymers specifically shown in both patent publications cannot sufficiently meet the recent heat resistance and weather resistance requirements mainly for automotive applications.

The present inventors conducted intensive studies to obtain a vinyl chloride resin composition with better heat resistance and weather resistance, and surprisingly found that the amount of butadiene and/or isoprene as a copolymer component was 20%. By using a crosslinked rubbery copolymer that is less than % by weight and contains a specific anti-aging agent, it has excellent heat resistance and weather resistance, and can be used for vinyl chloride resin, which is the purpose of mixing the crosslinked rubbery copolymer. It was found that the moldability and the effect of imparting creep resistance properties were also good, and the present invention was achieved.

There are no particular limitations on the vinyl chloride resin used in the present invention. Generally, those having a molecular weight of about 600 to 4000 are used, and the manufacturing method thereof may be any one of bulk polymerization, suspension polymerization, emulsion polymerization, solution polymerization, etc. In addition to homopolymers of vinyl chloride, It may also be a copolymer of vinyl chloride and other copolymerizable monomers. Monomers that can be copolymerized with vinyl chloride include α-olefins such as ethylene and propylene, vinyl esters such as vinyl acetate and vinyl stearate, vinyl ethers such as methyl vinyl ether and lauryl vinyl ether, methyl acrylate, and methacrylate. Examples include esters of acrylic acid and methacrylic acid such as methyl acid, acrylonitrile, styrene, acrylic acid, maleic anhydride, and the like.

The crosslinked rubbery copolymer used in the present invention can be obtained by a conventional emulsion polymerization recipe.

As the polymerization initiator, common radical initiators such as peroxides, redox compounds, persulfates, and azo compounds can be used. Anionic, cationic, nonionic or amphoteric surfactants are used as the emulsifier. Representative examples of molecular ff1M moderators include mercaptans such as tertiary dodecyl mercaptan and normal dodecyl mercaptan.

Examples of alkyl (meth)acrylates include methyl,
Mention may be made of ethyl, propyl, butyl, hexyl, octyl, acrylate or methacrylate. Particularly preferred is butyl acrylate. Examples of alkoxyalkyl (meth)acrylates include methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl acrylate or methacrylate.

The crosslinking monomer represents the following general formula (A) or (B) (A) R+ R+ group, where R is -C6H4- or 100-(R2
0 sho C- j11 (However, n is an integer from 1 to 4, R2 is C2H4, C3H6
or C4H8)] (B)
R1 (CH2=C-C-0 square R2 [wherein R1 represents H or a methyl group, R2 is a hydrocarbon residue, and n represents an integer from 3 to 5], Specifically, divinylbenzene, diisopropenylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Examples include propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and trimethylolpropane triacrylate, with divinylbenzene being particularly preferred.

The proportion of butadiene and/or isoprene constituting the copolymer is 5 to 20% by weight. If it is less than 5% by weight, the cold resistance will be poor, and if it is more than 20% by weight, the heat resistance and weather resistance will be significantly reduced.

The proportion of acrylonitrile is 10-50% by weight, preferably 15-30% by weight. If the acrylonitrile content is less than 10% by weight, the compatibility with the vinyl chloride resin will be poor, and the mechanical strength of the mixed composition will decrease. On the other hand, if it is 50% by weight or more, the cold resistance is poor.

The ratio of alkyl (meth)acrylate and/or alkoxyalkyl (meth)acrylate is 30 to 85
Weight%.

The amount of crosslinking monomer is 0.1-5.0% by weight. 0
．． If it is less than 1% by weight, the compression set properties of the blend with the vinyl chloride resin will be poor, and if it exceeds 5.0% by weight, the mechanical strength will be poor.

Polymerization is carried out at 0 to 50°C in an oxygen-free reaction atmosphere. Monomers, emulsifiers, initiators, molecular ffi regulators, and other additives may be added in their entirety before the start of the reaction, or may be added in arbitrary portions after the start of the reaction. Operation conditions can be changed arbitrarily. The polymerization method may be either continuous or batch.

The Mooney viscosity of the crosslinked rubbery copolymer thus obtained is not particularly limited, but is MLl+4 (100°C).
A value of 10 to 120 is desirable. More preferably, it is 20 to 30. In addition, the methyl ethyl ketone insoluble content of the crosslinked rubbery copolymer is 20 to 95%, preferably 50 to 95%.
It is necessary that When it is less than 20%, workability is poor and compression set is not improved, and when it exceeds 95%, elongation at break decreases.

To determine the amount of methyl ethyl ketone insoluble matter, add 50 cc of methyl ethyl ketone to 1 g of sample, let it stand at room temperature for 24 hours, and then shake it for 1 hour.
The insoluble matter obtained by centrifugation at 00 rpm was vacuum dried, and the weight of the insoluble matter was divided by the weight of the sample.

The anti-aging agent contained in the crosslinked rubbery copolymer, which is another feature of the present invention, is represented by the following formula.

[In the formula, RSR1 and R2 represent hydrogen or an alkyl group having 1 to 4 carbon atoms] Specifically, 4.4'(α,α-dimethylbenzyl)diphenylamine, 4.4′(α,α-diethyl benzyl) diphenylamine, 4,4'(α,α-dimethyl-4
-methylbenzyl)diphenylamine and the like.

The amount of antiaging agent added to the crosslinked rubbery copolymer is from 0.1 to 5.0% by weight per 100 parts of rubber. 0.1
If it is less than 5% by weight, the heat resistance will be poor, and if it is more than 5% by weight, the anti-aging agent will migrate to the surface of the molded product using the obtained vinyl chloride resin composition, resulting in poor appearance.

The anti-aging agent may be added to the crosslinked rubbery copolymer by adding it to latex, kneading it into rubber, or adding it when mixing with the vinyl chloride resin. In order to uniformly disperse the antiaging agent into the copolymer, it is desirable to add the antiaging agent in an emulsified form to the copolymer in a latex state.

The blending ratio of crosslinked rubbery copolymer to vinyl chloride resin depends on the application, but it is 1 part by weight for 100 parts by weight of vinyl chloride resin.
0 to 200 parts by weight is preferred.

In the vinyl chloride resin composition of the present invention, plasticizers, anti-aging agents, fillers, lubricants, foaming agents, flame retardants, pigments, etc. can be used as appropriate.

The mixing and molding of the vinyl chloride resin and crosslinked rubbery copolymer for producing the vinyl chloride resin composition of the present invention can be carried out in any manner as long as the respective ingredients are substantially uniformly dispersed, mixed, and kneaded. For example, the tri-blend powder may be tri-blended using a Henschel mixer or ribbon blender, and the tri-blend powder may be directly molded, or the tri-blend powder may be melt-kneaded using an extruder, rolls, etc., then pelletized, and then molded. The molding method may be extrusion molding, injection molding, blow molding, calendar molding, vacuum molding, or the like, depending on the shape and properties of the desired product.

Fields of use of the product of the present invention include hoses, gaskets, leather, films, wire covering materials, packing materials, moldings, cushion materials, floor tiles, and the like.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited by these.

Copolymer (1) used in the following examples and comparative examples
~(13) Emulsion polymerization was carried out at 30°C in an autoclave with an internal volume of 202°C according to the polymerization recipe shown below to obtain a crosslinked rubbery copolymer. [Table 1, Copolymer (1)] Polymerization recipe (parts by weight) Butadiene 12 Acrylonitrile 20 Butyl acrylate 67 Divinylbenzene 1 Water
250 Sodium dodecylbenzenesulfonate Tertiary dodecyl mercaptan 0.
3 Potassium persulfate 0.27 Cyanoethylated diethanolamine 0,15 Potassium hydroxide 0.10 Polymerization rate 90
%, the polymerization was stopped by adding 0.2 parts by weight of hydroxylamine sulfate per 100 parts by weight of monomer. After heating and removing residual monomers by steam distillation, the antioxidant 4,4'(α,α-dimethylbenzyl)diphenylamine (trade name: Nocrac CD Ouchi Shinko Kagakubun) is added per 100 parts by weight of rubber solids. made)
1.0 ffiffi part was added and the latex was coagulated with an aqueous calcium chloride solution. After washing the obtained coagulated material with water, it was dried at 50° C. under reduced pressure to prepare a sample for evaluation.

Table 1 below summarizes crosslinked rubbery copolymers and copolymers prepared using the same recipe by varying the monomer amount and the tertiary dodecyl mercaptan feed port. c Table-1, Copolymers (2) to QO)) Crosslinked rubbery copolymer (11) Using the latex used in crosslinked rubbery copolymer (1), octylated diphenylamine ( Product name: Nocrac AD Specially manufactured by Ohmukai Shinko Chemical)
A crosslinked rubbery copolymer was obtained in the same manner except that 1.0 parts by weight was used. Its composition, Mooney viscosity, and methyl ethyl ketone insoluble content were almost the same as those of the crosslinked rubbery copolymer (1).

Crosslinked rubbery copolymer: Using the latex used in crosslinked rubbery copolymer (1), 2,6-tert-butyl-
4-Methylphenol (Product name: Antage BH
A copolymer was obtained in the same manner, except that 1.0 part by weight of T (Kawaguchi Chemical System) was used. The composition, viscosity, and amount of insoluble matter were almost the same as those of the crosslinked rubbery copolymer (1).

Crosslinked rubbery copolymer (131) Using the latex used in crosslinked rubbery copolymer (1), tri(nonyl phenyl) phosphite (trade name: Antage TNP, Kawaguchi Chemical Co., Ltd.) was added as an anti-aging agent.1. The same procedure was carried out except that 0 parts by weight was used.The composition, viscosity, and amount of insoluble matter were almost the same as those of the crosslinked rubbery copolymer (1).

Examples 1 to 6, Comparative Examples 1 to 11 Henschel was prepared by adding 100 parts by weight of vinyl chloride resin (degree of polymerization 2500), 3 parts by weight of tribasic lead sulfate, and 60 to 80 parts by weight of dioctyl phthalate (hereinafter abbreviated as DOP). High-speed stirring was performed using a mixer to make the contents uniform, and when the contents became uniform, the above-mentioned crosslinked rubbery copolymer and all 60 to 100 polymers of the copolymer were added, and stirring was continued.

The resulting mixture was heated at 180°C using two 6-inch rolls.
The composition was kneaded for 10 minutes at
A sample for physical property evaluation was prepared by press molding at 0° C. for 5 minutes.

A tensile test of the obtained molded product was conducted in accordance with JIS K 6301, and heat resistance was determined using a Sunshine Carbon Weather Meter for samples that were heat aged for a specified time in a gear oven at 130°C. A tensile test was conducted on each sample exposed for a predetermined time at a black panel temperature of 83° C.±3° C. (no water spray), and the changes in tensile strength, elongation, and hardness were evaluated. Compression set characteristics are based on JIS K 6301, 70℃ x 22
Measurements were made in hours. The evaluation results are summarized in Table-2.

As is clear from the results shown in Table 2, the vinyl chloride resin composition according to the present invention has good mechanical strength and compression set characteristics, and is a material that has extremely excellent heat resistance and weather resistance. I understand that there is something.

Examples 7 to 9, Comparative Examples 12 to 16 The crosslinked rubbery copolymers and copolymers shown in Table 1 were blended according to the following recipe and kneaded with a hot roll at 180°C to form a resinous sheet. It was created. (0.8 thickness) PVC (degree of polymerization 1100) 100ABS (J
SP MK 60A) 60 copolymer
20DOP
35 Stabilizer 3 Physical properties were measured according to the following method.

Normal value: A JIS No. 1 dumbbell was punched out, and a tensile test was conducted at room temperature at a tensile speed of 200 mm/min.

Light resistance: A JIS No. 1 dumbbell was set in a fade meter using a mercury lamp (black panel temperature: 63°C), and after 15 hours of light irradiation, a tensile test was conducted.

Heat resistance: A tensile test was conducted on a sample heated in a gear oven at 120° C. for 100 hours in the same manner as the normal value measurement.

Surface smoothness: The smoothness of the obtained sheet surface was visually determined.

The results are summarized in Table 3.

It can be seen that the vinyl chloride resin composition according to the present invention is a material with an extremely excellent balance of mechanical strength, heat resistance, and light resistance.

The following margin [Effects of the Invention] The vinyl chloride resin composition according to the present invention is a composition with an excellent balance of mechanical strength, heat resistance, and weather resistance, and is a composition that has been used in conventional vinyl chloride resin compositions. It can be used in a wide range of applications for which vulcanized rubber has been used.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 100 parts by weight of vinyl chloride resin (I), 5 to 20% by weight of butadiene and/or isoprene, and 10% by weight of acrylonitrile as monomer units constituting the copolymer.
~50% by weight, alkyl (meth)acrylate and/or
or alkoxyalkyl (meth)acrylate 30~
85% by weight and 0.1 to 5.0% by weight of a crosslinking monomer represented by the following general formula (A) or (B), characterized in that the methyl ethyl ketone insoluble content is 50% or more, and the general formula (C ) Anti-aging agent 0.1-5
．． Crosslinked rubbery copolymer (II) containing 0% by weight 10~
A vinyl chloride resin composition comprising 200 parts by weight. (A) CH_1=C-R-C=CH_2 [In the formula, R_1 and R_1' both represent H or a methyl group, and R is -C_6H_4- or ▲There are numerical formulas, chemical formulas, tables, etc.▼ (However, n is an integer from 1 to 4, R_2 is C_2H_4, C
_3H_6 or C_4H_8] (B) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_1 represents H or a methyl group, R_2 is a hydrocarbon residue, and n is an Represents an integer] (C)▲Mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R, R_1, R_2 are hydrogen or have 1 to 4 carbon atoms.
represents an alkyl group]