JPH04236246A - Foamed vinyl chloride - Google Patents

Abstract

PURPOSE:To obtain a foam at high production speed, in an improved yield at low cost by forming a pure vinyl chloride resin of crosslinking type into foam and producing foam having 50mm thickness by heat generating action of iron oxide by overcoming limitation of 10mm thickness of foam. CONSTITUTION:A polyvinyl chloride resin is mixed with a crosslinking agent, a stabilizer, a foam agent, a foam stabilizer and iron oxide to give a raw material and a vinyl chloride foam of crosslinking type is produced by one-stage or two-stage foaming method to give vinyl chloride foam useful as insulating material of foam texture of new molecule bond, a core material and a back-up agent.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed product obtained by adding a foaming agent, a stabilizer, an iron oxide, and a foam stabilizer to a crosslinked polyvinyl chloride resin, mixing them, and foaming them.

0002

[Prior art] As a vinyl chloride foam,
Foams described in Japanese Patent Publication No.-2184, Japanese Patent Publication No. 52-26776, and Japanese Patent Publication No. 63-7574 are known and are on the market.

0003

[Problems to be Solved by the Invention] However, this type of foam is composed of vinyl chloride resin powder, liquefied butane gas (a blowing agent), and a solvent.
It is necessary to mix the constituent materials uniformly by kneading in a sealed kneader for 40 minutes, and in addition, the melt is forced into an extruder, and then the material is forced into a mold pressurized to 200 kg/m by this extruder. After filling the mold, heat it to 145℃~160℃ using boiler steam.
℃ for about 40 to 60 minutes to gel in the mold, cool the mold under pressure to room temperature to complete one-stage foaming,
Next, this was stored in a hot air circulating machine and heated at 90° to 100° C. for about 60 minutes to foam in two stages to form a foam product.

[0004] Therefore, the foam itself requires a large number of man-hours, and in addition, the equipment is too precise and is not suitable for mass production, which has the disadvantage of requiring a high investment in equipment. In addition, the productivity is two-stage foaming, and there is a heating process of 40 to 60 minutes, and the thickness is 10 mm.
However, it has the disadvantage that it has limited adhesive properties, has poor adhesion, and is shaped like a slab form, making it impossible to mold with other parts and always requiring an adhesive. Furthermore, the manufacturing time is long, the yield is low, and the product is expensive, which greatly limits its applications.

[0005]

[Means for Solving the Problems] In order to eliminate such drawbacks, the present invention liquefies polyvinyl chloride resin and adds a quaternary ammonium salt, a polyvalent epoxy compound, a crosslinking agent,
Raw materials mixed with stabilizer and iron oxide, foaming agent, and inorganic powder (calcium carbonate, aluminum hydroxide, etc.) if necessary
After adding and mixing, plastisol reacts, foams, cures, and demolds, continuously forming a foam in about 30 minutes, and is not affected by the shape of the facing material. The aim is to supply polyvinyl chloride foam that can be used for a variety of purposes such as molding materials, etc., is low cost and strong, and can be manufactured at a much higher speed than before.

[0006]

[Example] Below, an example of the vinyl chloride foam according to the present invention will be described in detail. That is, the vinyl chloride foam according to the present invention is a foam of a desired hardness that is foamed from a crosslinked polyvinyl chloride resin and a blowing agent to about 10 to 60 times the foam. To explain further, the polyvinyl chloride resin is made of one of a polymer of vinyl chloride alone and a copolymer of vinyl chloride with vinyl acetate, acrylic ester, vinyl ether, vinyl ester, ethylene, etc. Note that the viscosity of the vinyl chloride resin can be reduced by changing the molecular weight. In the present invention, the quaternary ammonium salt that acts as a crosslinker and a catalyst is a compound represented by the chemical formula R4NX, where R represents an alkyl group such as a methyl group or an allyl group such as a benzyl group, and the four Rs are the same. Even if they are different types, any of them can be used as the quaternary ammonium salt of the present invention. Also, heterocyclic ammonium salts in which R's are bonded to each other to form a ring, such as N-methylpyridinium salts, etc. can be equally used. In the formula, N represents a nitrogen element. X in the formula is a halogen element represented by chlorine, an acid group such as a sulfone group, or a nitric acid group, and is not related to the type of acid group. In addition, 4
The amount of the grade ammonium salt added is in the range of 0.02 to 10 parts by weight per 100 parts by weight of the vinyl chloride resin.

As the crosslinking aid used in the present invention, it is preferable to use a polycarboxylic acid metal salt having two or more carboxyl groups or an epoxy resin.

[0008] The blowing agent used in the present invention is 100~
Compounds that decompose at 250°C and generate gas, such as azodicarbonamide, are preferred for closed-cell structures, while aluminum hydroxide (250-350°C) and zinc borate (330°C) form open-cell foam structures. used for

The polyvalent epoxy compound that functions as a crosslinking agent and adhesive used in the present invention is a compound having two or more epoxy groups in one molecule, such as epoxidized soybean oil, epoxidized linseed oil, and epichlorohydrin. It is commonly called epoxy resin etc. obtained by condensing polyvinyl chloride and bisphenol A, and is a compound that has a certain degree of compatibility with vinyl chloride resins or their plasticizers. The amount of the polyvalent epoxy compound is in the range of 1 to 50 parts by weight based on 100 parts by weight of the vinyl chloride resin.

The epoxy curing agent used in the present invention is a conventional epoxy resin curing agent. Specific examples thereof include one of amine compounds, diamine compounds, polyamine compounds, polyamides, amino acids, polybasic acids having two or more carboxyl groups, and acid anhydrides thereof. Since the reaction between the amine curing agent and the epoxy compound is extremely fast, it is often unsuitable for the usage conditions of general vinyl chloride resins, but it is useful for paints. In addition, curing agents suitable for the general reaction conditions are amino acids such as ε-aminocaproic acid, dibasic acids such as adipic acid, acid anhydrides such as succinic anhydride, maleic anhydride, phthalic anhydride, trimellitic anhydride, etc. Acids such as pyromellitic anhydride, methylhexahydrophthalic anhydride, and condensates of these polybasic acids and glycol are useful, and can be used alone or in combination. The amount of epoxy curing agent is 0.2 parts by weight per 100 parts by weight of vinyl chloride resin.
to 20 parts by weight.

[0011] As the plasticizer used in the present invention, for example, dioctyl phthalate can be used as desired. Therefore, the present invention provides a wide range of crosslinked vinyl chloride resin foams ranging from hard to soft.

Since the stabilizer used in the present invention directly acts on the crosslinking reaction of the vinyl chloride resin, care must be taken regarding its type and amount. For example, dibasic lead phthalate, tribasic lead sulfate, zinc laurate, etc. are added in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the vinyl chloride resin.

The additive used in the present invention is one of pearlite particles, vermiculite, calcium carbonate, shirasu balloon, aluminum hydroxide, and calcium silicate, and is used to improve the mechanical strength and fire resistance of the foam or as a blowing agent. is also helpful.

[0014] The foam stabilizer used in the present invention is silicone, which helps to make the cells of the foam structure into a uniform shape, increases the strength of the entire foam, improves the insulation performance, and reduces the amount of resin, which also contributes to cost reduction. It is something to do.

[0015] The iron oxide used in the present invention is foamed before or after the crosslinking reaction to serve as an auxiliary agent for decomposing the foaming agent and to form a foam, and the amount added depends on the reaction rate, expansion ratio, The amount of polyvinyl chloride resin 100 is 5 to 50 parts by weight, depending on whether foaming is performed after crosslinking or crosslinking and foaming are performed simultaneously.

Briefly explaining the method for producing a foam according to the present invention, when foaming is performed after completion of crosslinking, the components are heat-treated at a temperature below the dispersion start temperature of the blowing agent to complete the crosslinking, and then the blowing agent is decomposed. There is a method of foaming at a high temperature higher than the temperature (two-stage foaming method), and a method of proceeding with the crosslinking reaction and foaming at the same time (single-stage foaming method). Note that either method can be manufactured continuously.

Example 1 (Two-stage foaming method) Blending ratio Polyvinyl chloride
100 copies T・C・P──
────┐
10 copies
│(Plasticizer) Dioctyl phthalate─┘
30 parts Epoxidized linseed oil (crosslinking agent, adhesive)
5 parts Phthalic anhydride (crosslinking aid)
3 parts tribasic lead sulfate (
stabilizer)
Part 3 Azodicarbonamide (foaming agent)
40 parts Trimethyllauryl ammonium chloride (crosslinking catalyst) 1 part Iron oxide (blowing agent)

10 parts Silicone (foam stabilizer)
One part of the above material was kneaded for 2 minutes using a heated roll at 160° C. to form a sheet about 1 mm thick. This sheet was heat treated at 100° C. for 30 minutes and then foamed at 230° C. to obtain a foam approximately 70 times larger.

Example 2 Blending ratio Polyvinyl chloride
100 parts dioctyl adipate
20 parts Butylbenzyl phthalate (plasticizer)
20 parts epoxidized linseed oil

5 parts Anhydrous trimellit (crosslinking aid)
2 parts tribasic lead sulfate (stabilizer) 10
Part Silicone (foam stabilizer)
Part 1 Azodicarbonamide
10 parts polyethylene oxide (lubricant)
2 parts Zinc oxide (
foaming aid)
1 part Tetrapropylammonium bromide 1 part Iron oxide

15 parts of the above material was kneaded to form a plastisol, which was laminated on a mold to a thickness of 5 mm, and then heated at 230°C to obtain a foam with an expansion of about 30 times.

[0019]

Effects of the Invention As described above, according to the vinyl chloride foam according to the present invention, (1) the foam can be manufactured to any thickness of about 10 to 50 mm. ■Weather resistance and chemical resistance are 10 times higher than conventional chain bonded PVC foam due to network structure bonding.
It has twice the performance. ■By using pure vinyl chloride resin as the raw material, costs can be significantly reduced and yields are also good. ■Excellent stain resistance, gloss, and hardness. ■ Adhesiveness is also present during foam production, making it easy to integrate with other parts. ■Productivity is greatly speeded up. It has the following characteristics and effects.

Claims (2)

[Claims] [Claim 1] A blowing agent is added to the cross-linked polyvinyl chloride resin.
A vinyl chloride foam characterized by being formed by adding iron oxide and a foam stabilizer. [Claim 2] Perlite grains, vermiculite, calcium carbonate, shirasu balloons, aluminum hydroxide,
A vinyl chloride foam characterized in that it contains one or more additives such as calcium silicate.