JPH066657B2 - Crosslinkable vinyl chloride composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crosslinked vinyl chloride resin composition, which can be crosslinked by heating and kneading in the same step as a conventional vinyl chloride resin composition, and easily molded. Therefore, it can be suitably used in the fields that take advantage of cross-linking characteristics such as heat resistance, high elasticity, abrasion resistance, and solvent resistance.

"Conventional technology and problems" As a cross-linking technology using an organic silane compound,
No. 49-41333 vinyl chloride monomer and an organosilane having a non-conjugated olefinically unsaturated group such as vinyltriethoxysilane are copolymerized, and the resulting copolymerization product is treated with a siloxane condensation catalyst. A method of crosslinking by exposure to water in the presence of (CH ₃ O) ₃ Si (CH ₂ ) ₃ N on a polyvinyl chloride resin as disclosed in Japanese Patent Publication No. 52-4319.
A method in which an amino group-containing organosilane compound such as H ₂ is reacted and the reaction product is exposed to hot water in the presence of a siloxane condensation catalyst to crosslink, as disclosed in JP-A-53-27698. There is a method in which an organic silane containing a olefinic unsaturated group is kneaded with a polyvinyl chloride resin in the presence of an organic peroxide to cause a grafting reaction, and the same treatment as described above is performed to crosslink. In these methods, a silyl group is added to the main chain of a polyvinyl chloride resin by copolymerization or a chemical reaction, and crosslinking cannot be achieved unless it is exposed to hot water or steam in the presence of a silanol condensation catalyst. It requires a step of modifying the vinyl chloride resin and a step of post-crosslinking, and therefore is complicated, has poor productivity, and is not a practically advantageous crosslinking technology. Moreover, since it is exposed to hot water or steam, it cannot be applied to soft vinyl chloride resin containing a plasticizer.

As a technique for cross-linking a vinyl chloride composition, a cross-linking method in which a cross-linking agent such as triallyl isocyanurate and trimethylol propane trimethacrylate is added to an ordinary vinyl chloride resin, and radiation such as electron beam, γ-ray and X-ray is applied. , Japanese Patent Publication No. 52-9463, a cross-linking method using trithiocyanuric acid, and a method using triallyl isocyanurate and an organic peroxide as disclosed in Japanese Patent Publication No. 43-9376. ing. Radiation cross-linking is partly carried out for electric wires and film applications, but irradiation equipment is necessary, processing costs are unavoidably high, and it is necessary that the object to be processed has a uniform thickness, Not suitable for cross-linking extrusion-molded products and injection-molded products with complicated shapes.
For crosslinking other than radiation, there is a method of utilizing an ionic reaction, but magnesium oxide, zinc oxide, etc. are required, and the reaction time is long, so thermal decomposition of the vinyl chloride resin is unavoidable. In the method using an organic peroxide, it is necessary to block the air, and crosslinking may occur during kneading in the processing stage so that molding cannot be performed, or the molded article is markedly colored because it is crosslinked by heating above the decomposition temperature of PVC. It has the drawback of not being practical.

"Means for solving the problem" In view of such circumstances, the present inventors, without having the above-mentioned drawbacks, heat and melt-knead using a conventional production process of a vinyl chloride-based composition to crosslink, Can be easily molded,
Moreover, the inventors have found a novel crosslinkable vinyl chloride resin composition having excellent heat resistance and improved compression set, and completed the present invention.

That is, the present invention is: 1. A crosslinkable vinyl chloride composition comprising the following components (a), (b) and (c); (a) 100 parts by weight of vinyl chloride resin (b) the following general formula [1] (In the formula, R ¹ and R ² are hydrogen or alkyl having 1 to 10 carbon atoms,
A monovalent hydrocarbon group selected from aryl and aralkyl groups, X is a hydrolyzable group, and n is an integer of 0 to 2. ) At least one hydrolyzable silyl group in the molecule
Two diallyl phthalate monomers, or molecular weight 20
000 or less diallyl phthalate prepolymer, or a silyl group-containing compound which is a copolymer containing a diallyl phthalate having a molecular weight of 300 to 100,000 and an acrylic acid ester and / or a methacrylic acid ester 5 to 200 parts by weight (c) a plasticizer 0 to 250 The contents are parts by weight.

The vinyl chloride resin used in the present invention is a vinyl chloride resin obtained by homopolymerizing a vinyl chloride monomer or a vinyl chloride copolymer resin containing vinyl chloride as a main component, that is, containing 85% or more. Is, for example, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-ethylene copolymer resin vinyl chloride-propylene copolymer resin, a copolymer resin of vinyl chloride and acrylic acid or its ester with vinyl chloride and methacrylic acid or its ester. Examples thereof include copolymer resins and copolymer resins of vinyl chloride and alkyl vinyl ether. These vinyl chloride copolymer resins may be used by blending in a poor position (up to 30%) with respect to the vinyl chloride resin.

These vinyl chloride resins and copolymer resins thereof can be produced by suspension polymerization, bulk polymerization, emulsion polymerization,
A commercially available product generally called vinyl chloride resin can be used.

The average degree of polymerization of the vinyl chloride resin is preferably from 500 to 6000, and when the average degree of polymerization is less than 500, it is difficult to knead with a kneading method of a normal vinyl chloride resin, which is unsuitable, and the average degree of polymerization is Even if it exceeds 6000, it is difficult to knead, which is not preferable. In terms of ease of kneading, the average degree of polymerization is 700
~ 5000 is preferred.

The silyl group-containing compound containing at least one silyl group in the molecule used in the present invention is an addition reaction of a silicon hydride compound and a compound having a carbon-carbon double bond at the terminal or side chain using a platinum catalyst. By doing so, it is basically manufactured.

Examples of compounds having a carbon-carbon double bond at the terminal or side chain include diallyl phthalate compounds and diallyl phthalate copolymers.

As the diallyl phthalate compound having a carbon-carbon double bond, a diallyl phthalate monomer or a prepolymer is included, and a commercially available compound can be used.

The diallyl phthalate having a carbon-carbon double bond and an acrylic ester or methacrylic ester copolymer are
Polymerized with a polymerization initiator such as an azo compound or peroxide,
The number of double bonds can be adjusted by changing the amount of diallyl phthalate used as a copolymerization component.

As the silicon hydride compound, halogenated silanes such as trichlorosilane, methyldichlorosilane, dimethylchlorosilane, and phenyldichlorosilane; trimethoxysilane, triethoxysilane, methyldimethoxysilane,
Alkoxysilanes such as methyldiethoxysilane and phenyldimethoxysilane; Acyloxysilanes such as methyldiacetoxysilane and phenyldiacetoxysilane; Kelas such as bis (dimethylketoximate) methylsilane and bis (cyclohexylketoximate) methylsilane Toximate silanes may be mentioned.

When the silyl group-containing compound is a diallyl phthalate-based compound, a diallyl phthalate monomer or a molecular weight of 20000 is used.
The following diallyl phthalate prepolymer, or molecular weight
A preferable example is a polymer containing 300 to 100,000 diallyl phthalate and an acrylic acid ester or a methacrylic acid ester.

These silyl group-containing compounds can be added in an amount of 5 to 200 parts by weight per 100 parts by weight of the vinyl chloride resin. When the amount of the compound is less than 5 parts by weight, the gel content of the vinyl chloride resin composition is small, and it is difficult to exhibit the physical properties. The compound is 200
If the amount is more than parts by weight, the crosslinked vinyl chloride resin composition is not practical because it becomes hard and brittle, and it is difficult to process and the manufacturing cost increases.

The plasticizer is 0 to 250 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. That is, it can be crosslinked from fairly hard to very soft.

Examples of the plasticizer used in the present invention include phthalic acid esters such as dioctyl phthalate, dinonyl phthalate and diisodecyl phthalate; aliphatic dibasic acids such as dioctyl adipate; trioctyl trimellitate;
Polyester plasticizers, epoxidized products such as epoxidized soybean oil, phosphoric acid esters such as tricresyl phosphate, chlorinated paraffins, and other plasticizers usually used in soft vinyl chloride resin compositions can be used. In order to improve properties such as heat resistance and compression set by crosslinking, so-called soft blending with a plasticizer amount of 30 to 250 parts by weight is particularly preferable.

A catalyst that promotes a siloxane bond can be effectively used in order to help the crosslinking of the resin composition of the present invention. As the crosslinking promoting catalyst, a hydrolyzable group such as an alkoxy group directly bonded to a Si atom in a silyl group-containing compound is silanolized by contact with water, and then two silanol molecules are dehydrated and condensed to form Si-O. Any compound can be preferably used as long as it has a function of promoting a reaction of forming a -Si bond and crosslinking. The amount of such catalyst is in the range of 0.001 to 50 parts by weight, more preferably 0.1 to 30 parts by weight. The silanol condensation catalysts advantageously used in the present invention are known to be a variety of effective materials, and organometallic compounds such as metal salts of carboxylic acids, titanium chelates, alkyl titanates,
Includes alkyl zirconate esters, organic bases and organic acids. Specific examples of such catalysts include dibutyltin dilaurate, dibutyltin dioctanoate, dibutyltin diacetate, stannous octoate, stannous oleate,
Dibutyltin phthalate, lead octanoate, zinc 2-ethylhexonate, cobalt naphthenate, cobalt octanoate, iron 2-ethylhexonate, bis (acetylacetonyl) di-isopropyl titanate, di-isopropoxytitanium di (e, chill) Acetoacetate), tetrabutyl titanate tetrabutyl zirconate, ethylamine,
Hexylamine, laurylamine, dibutylamine, piperidine, octodecylamine acetate, p-toluenesulfonic acid and acetic acid. Preferred catalysts are organometallic compounds, in particular tin carboxylates such as dibutyltin dilaurate, dibutyltin diacetate, dibutylneltin dioctanoate, and dibutyltin phthalate.

The catalyst used as a heat stabilizer for vinyl chloride-based resins such as dibutyltin dilaurate may be added with no heat stabilizer, but from the viewpoint of heat stability and kneading processability of the composition, tribasic lead sulfate is used. For processing vinyl chloride resin compositions such as lead-based heat stabilizers, Ba / Zn-based heat stabilizers, Ca-Zn-based heat stabilizers, Cd-Ba-based heat stabilizers, zinc stearate, calcium stearate, etc. It is preferable to use the heat stabilizer used in combination.

In addition, the resin composition of the present invention may be compounded with additives generally used in vinyl chloride resin compositions, such as fillers, lubricants, processing aids, thermoplastic elastomers, foaming agents, UV absorbers and pigments, if necessary. May be used in combination, and the type and amount thereof may be appropriately selected depending on the purpose.

The resin composition of the present invention is blended with a mixer such as a ribbon blender, melted and kneaded with a kneading machine such as a Banbury mixer, a mixing roll, and an extruder to be kneaded into a sheet, pellets or any other shape. it can. The treatment temperature is preferably 120 to 200 ° C., the optimum temperature is selected depending on the average degree of polymerization of the vinyl chloride resin in the composition, the type and amount of the plasticizer, and the amount of the type of silyl group-containing vinyl polymer,
The treatment time may be the minimum time for the composition to gel and obtain a molded product, and a time of 2 minutes or more is usually sufficient.

When a catalyst that promotes a siloxane bond is used, it is preferable to separate the silyl group-containing compound and the catalyst that promotes a siloxane bond. Either one of the components is added to the composition immediately before kneading, or the Banbury catalyst is used. It can also be added immediately after the start of kneading in a mixer or mixing roll.

"Examples" Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto.

The physical properties described in the following examples were measured as follows.

Gel fraction: The crosslinked sample (roll sheet) was put in a 350 mesh wire net and immersed in tetrahydrofuran heated and boiled in a constant temperature water bath at 80 ° C. for 4 hours to determine the gel fraction.

Tensile test: Measured according to JIS K6301.

Compression set: In accordance with JIS K6301, measurement conditions were 70 ° C x 22 hours, and compression rate was 25%.

Shape heat retention at high temperature: Blend the compounds shown in Tables 1 and 3 and immediately roll the blend at a temperature of 150 ° C.
Knead for 5 minutes to make a masticated sheet about 3mm thick,
This sheet is cut into about 3 mm squares and pelletized, and the pellets are L / D = 22, compression ratio 3.0 using a 30 mm single-screw extruder using a full-screw extruder, outer diameter 11 mm, wall thickness 1 mm.
Extruded into a tube shape. The molding conditions were set to a cylinder temperature of C 140 ° C., C 150 ° C., C 160 ° C. and a die temperature of 155 ° C. from the hopper side, and the screw rotation speed was 30 rpm. This tube was cut into a length of 30 mm and left in an air oven at 200 ° C. for 1 hour to determine the rate of change in tube length.

Examples 1, 3, 4 and Comparative Example 1 Vinyl chloride resin (Kanevinyl S-1003: manufactured by Kanebuchi Chemical Co., Ltd.) was added to 100 parts (part by weight, hereinafter the same) of a silyl group-containing diallyl phthalate compound (90 ° C.). 100g of styrene and 160g of diallyl phthalate in 1kg of toluene solvent heated to room temperature
g, methyl methacrylate 400 g, methacrylate-n-butyl 190 g, acrylic acid-n-butyl 140 g, acrylic acid
A solution prepared by dissolving 20 g of azobisisobutyronitrile in 20 g of 10 g of n-dodecyl mercaptan was added dropwise and reacted for 10 hours to obtain a diallylphthalate-containing polymer having a molecular weight of 8000. 200 g of the polymer solution contained 15 parts of methyldimethoxysilane.
g, and a solution of 0.005 g of chloroplatinic acid dissolved in isopropanol were added, and the reaction was carried out at 90 ° C. for 6 hours under a sealed condition. ) 50
Parts were blended, blended and blended as shown in Table 1 below, and roll-kneaded to obtain a masticated sheet, and physical properties were measured. The results are shown in Table 1.

Example 2 100 parts of vinyl chloride resin (Kanevinyl S-1003) and silyl group-containing diallyl phthalate prepolymer [diallyl phthalate prepolymer (trade name "Dap L", manufactured by Osaka Soda Co., iodine value about 80) 1 kg, platinum chloride 0.0001 g of acid and hydroquinone were dissolved in 1000 ml of toluene. To this solution, 350 ml of methylethoxysilane was added and reacted at 90 ° C. for 3 hours to obtain a silyl group-containing diallyl phthalate prepolymer. 50 parts were blended, blended and blended as shown in Table 1 below, roll-kneaded to obtain a masticated sheet, and physical properties were measured. The results are shown in Table 1.

At the same time, for comparison, the same operation was repeated when 2 parts of the silyl group-containing diallyl phthalate copolymer was added, and the results obtained are shown in Table 1.

As can be seen from Table 1, the silyl group-containing diallyl phthalate-based copolymers, the diallyl phthalate prepolymers of 50 parts each and the diallyl phthalate-based copolymers of 150 parts each have a low compression set and a high compression set at a high temperature. It is very good to keep the shape. The gel content is 33% even with a hard compound without the addition of a plasticizer. When the addition amount of the silyl group-containing diallyl phthalate copolymer is 2 parts, the compression set is large,
The heat resistance is also poor.

"Effects of the Invention" The resin composition of the present invention has a sheet form, which easily undergoes crosslinking during melting and kneading with a Banbury mixer, roll, etc.
It can be taken out in any shape such as pellets, and the obtained crosslinked pellets can be easily subjected to molding processing such as extrusion molding, and can greatly improve the compression set, heat resistance, etc. of the molded product. is there.

Claims (2)

[Claims] 1. A crosslinkable vinyl chloride-based composition comprising the following components (a), (b) and (c); (a) 100 parts by weight of vinyl chloride-based resin (b) the following general formula [1] ] (In the formula, R ¹ and R ² are hydrogen or alkyl having 1 to 10 carbon atoms,
A monovalent hydrocarbon group selected from aryl and aralkyl groups, X is a hydrolyzable group, and n is an integer of 0 to 2. ) At least one hydrolyzable silyl group in the molecule
Two diallyl phthalate monomers, or molecular weight 20
000 or less diallyl phthalate prepolymer, or a silyl group-containing compound which is a copolymer containing a diallyl phthalate having a molecular weight of 300 to 100,000 and an acrylic acid ester and / or a methacrylic acid ester 5 to 200 parts by weight (c) a plasticizer 0 to 250 Parts by weight 2. The composition according to claim 1, which comprises 0.1 to 30 parts by weight of a tin carboxylate compound as a silanol condensation catalyst.