KR0139883B1 - Pvc resin foam composition - Google Patents

Abstract

The present invention relates to a PVC resin foam composition, with respect to PVC-based resin 100 PHR, quaternary phosphonium salt 0.05-5 PHR, epoxy resin 1-40 PHR, epoxy resin curing agent 0.1-20.0 PHR, foaming agent 1-40 PHR, plasticizer It is composed of 5 to 100 PHR, and stabilizers 0.1 to 6 PHR, and relates to a PVC resin foam composition capable of foaming at high magnification while simplifying the manufacturing process by allowing crosslinking and foaming simultaneously without sheet aging during the manufacturing process.

Description

PVC resin foam composition

The present invention relates to a PVC resin foam composition, and more particularly to a PVC resin foam composition of high magnification such that crosslinking and foaming occur simultaneously using a crosslinking agent.

The crosslinked PVC foam not only has excellent secondary formability and high frequency welding property, but also has a soft touch and good cushioning property, which can be used for cushioning and sundries of automobile interior materials.

As a method of obtaining a PVC crosslinked foam having a high magnification, there is a method of preparing a foam by thermally decomposing the foaming agent under pressure and then returning it to normal pressure while cooling (JP-A 41-12632). However, the production time is long and expensive. In the same way, it was difficult to continuously produce a wide sheet.

In order to solve the above problems, a method of kneading a crosslinking agent, a blowing agent, and other additives in PVC to produce a sheet using an extruder or a calender at a temperature where crosslinking does not occur, and then foaming simultaneously with crosslinking in a foaming oven has been studied. .

In particular, the method of manufacturing high magnification foamed PVC sheet described in US Pat. No. 4,986,860 is a secondary crosslinking agent (PP) after mixing a plasticizer, a safety agent, and other additives with a vinyl chloride (PVC) copolymer having a hydroxyl or carboxyl group as a reactor. Isocyanate or amine) and a blowing agent are kneaded to produce a PVC sheet using an extruder, and then crosslinked and foamed by heating while continuously passing through a vertical or horizontal foaming oven to produce a high magnification foam.

In addition, as described in Japanese Patent Application Laid-Open No. 63-7574, after kneading at 155 ° C. using an epoxy resin as a crosslinking agent and an ammonium salt as a crosslinking catalyst, crosslinking was carried out at 110 ° C. for 15 hours and then crosslinked. The foaming is carried out while passing through a foam oven, and a high magnification foam is produced.

However, the manufacturing technology according to US Pat. No. 4,986,860 has a disadvantage in that the product is expensive because it is required to synthesize PVC having a hydroxyl group or a carboxyl group as a reactor, and raw materials other than isocyanate or amine used as a crosslinking agent and azodicarbonamide as a blowing agent. After kneading, the crosslinking agent and the blowing agent had to be added. In addition, the manufacturing technique according to Japanese Patent Application Laid-Open No. 63-7574 is very slow in reaction rate of the ammonium salt as a crosslinking catalyst. Should be aged for a while. If the precise temperature control was not possible in this aging process, there was a fire risk due to the temperature rise due to the heat accumulation inside the rolled sheet. In addition, since it is difficult to maintain a uniform temperature until the inside of the roll, it causes a non-uniformity of the product and a defect of the foam, and thus has a disadvantage in that it is difficult to manufacture a foam sheet having a foam ratio of 14 times or more.

Therefore, the present invention aims to continuously produce a high-magnification foam in which fine cells are formed by increasing the melt viscosity of PVC so as to withstand the diffusion of the generated gas even at a high temperature at which the blowing agent is pyrolyzed by crosslinking the PVC.

PVC resin foam composition for achieving the object of the present invention as described above for the PVC-based resin 100 PHR (Per Hundred Resin), quaternary phosphonium salt 0.05 to 5 PHR, epoxy resin 1 to 40 PHR, epoxy resin curing agent 0.1 To 20.0 PHR, blowing agent 1 to 40 PHR, plasticizer 1 to 100 PHR, and stabilizer 0.1 to 6 PHR.

Hereinafter, the present invention will be described in more detail.

As the vinyl chloride resin used in the present invention, any of a vinyl chloride homopolymer and a copolymer of vinyl chloride and vinyl acetate, acrylic acid ester, ethylene and the like can be used.

The quaternary phosphonium salt used as the crosslinking catalyst in the present invention is a compound represented by the formula R ₁ PX, wherein R represents an alkyl group or an aryl group having 1 to 20 carbon atoms, and when the four R's are the same species or different kinds, It can be used as a crosslinking catalyst of. Moreover, the phosphonium salt which R couple | bonds with each other and forms a ring can also be used. In the formula, X represents halogen, acetate, sulfate, diethyl phosphorodithioate anion and the like and affects the reaction depending on the type of acid group.

The amount of quaternary phosphonium salt used in the present invention is selected from the type and amount of crosslinking aid within the range of 0.05 to 5 PHR with respect to 100 PHR of resin and the conditions for producing the foam.

As the crosslinking aid in the present invention, an epoxy resin and an epoxy resin curing agent are useful. The epoxy resin is preferably 100 to 5000 epoxy equivalents such as epoxidized soybean oil, epoxidized linseed oil, epoxy-alkyl ester, bisphenol A epoxy resin, It can be used individually or in combination, The usage-amount is suitably 1-40 PHR with respect to 100 PHR of resin.

Examples of the epoxy resin curing agent include amine salts, organic acid anhydrides, polyvalent carboxylic acid metal salts, monovalent or divalent metal oxides, and the like, and can be used alone or in combination. Moreover, the usage-amount of an epoxy resin hardening | curing agent has a preferable range of 0.1-20.0 PHR according to the kind and quantity of an epoxy resin.

As the amine salts, diethyltriamine, benzyldimethylamine, triethylene tetramine, dicyandiamide, metaphenylenediamine and the like can be used, and as the organic acid anhydride, phthalic anhydride, maleic anhydride, dodecyl succinic anhydride, hexahydrophthalic anhydride, Methylhexahydrophthalic anhydride, pyromellitic anhydride, methyltetrahydrophthalic anhydride, benzophenonetetracarboxylic anhydride, trimellitic anhydride and the like are useful.

As the polyvalent carboxylic acid metal salt, divalent or trivalent metal salts selected from barium, cadmium, magnesium, zinc, calcium, etc. are suitable. As metal oxides, Li ⁺ , Na ⁺ , K ⁺ , Ca ²⁺ , Zn ²⁺ And metal oxides such as Cd ²⁺ are suitable.

In the present invention, the plasticizer and stabilizer used in the compounding of the vinyl chloride resin affect the crosslinking reaction rate, so it is necessary to pay attention to the type and amount of the compound.

As a plasticizer, the plasticizer generally used for the soft use of vinyl chloride resin, ie, phthalate plasticizers, such as dioctyl phthalate and diisodecyl phthalate, dibasic ester plasticizers, such as dioctyl adipate and dioctyl sebacate, and trimellitic acid Ester plasticizers, polyester plasticizers and the like can be used alone or in combination of two or more thereof, and the content thereof can be arbitrarily adjusted according to the hardness of the product within the range of 5 to 100 PHR.

As a stabilizer, organic acid metal salts, such as Ba, Zn, Ca, Pb, and Sn, which are generally used for PVC mixing, may be used alone or in combination, and may be arbitrarily adjusted according to the processing conditions of the foam within the range of 0.1 to 6 PHR.

As the chemical foaming agent used in the present invention, azodicarbonamide, which is a compound that generates decomposition gas in the range of 140 to 230 ° C, is most suitable, but other blowing agents can be used, and the amount of the foaming agent is preferably 1 to 40.

Fillers, pigments, and other resins may be optionally blended within a range that does not affect the crosslinking reaction.

The composition according to the invention is made into a sheet after dry blending and uniformly dispersing. The prepared sheet is immediately crosslinked and foamed without a separate aging time to obtain a three-dimensional expanded microscopic uniform PVC foam sheet.

That is, the present invention can solve various problems such as the complexity of the manufacturing process and the increase in manufacturing cost by eliminating the aging process, and can produce a foam sheet having a uniform beginning and end of the product.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

Example 1

The blend was dry blended at 80 ° C. to uniformly disperse the resin and additives and then cooled to 25 ° C. The mixture was then fed to an extruder to produce a 1.2 mm thick sheet at a rate of about 5 m / min at a temperature of 140 ° C. The sheet is cross-linked and foamed while passing through the foam sheet at a preheating temperature of 150 ° C and a heating temperature of 220 ° C in a horizontal foam oven at a rate of 3 to 4 m / min to expand three-dimensionally with a foaming ratio of 25 times and a thickness of 3 mm. Fine uniform foam sheets were obtained.

Example 2

The blend is dry blended at 120 ° C., uniformly dispersed in a super mixer, and then moved to a Banbury mixer at 100 ° C. to thoroughly knead the blend for 4 to 5 minutes, dropped onto a mixing roll, and kneaded at a temperature of 140 ° C. to a calender roll. A sheet having a thickness of 0.4 mm was prepared. The prepared sheet was laminated to three diameters in a plywood maker to prepare a sheet having a thickness of 1.5 mm, and then crosslinked and foamed while passing through the sheet under a preheating temperature of 140 ° C. and a heating temperature of 220 ° C. in a foam oven. As a result, a foaming ratio of 30 times and a uniform fine foam having a thickness of 4 mm were obtained.

Comparative Example 1

The blend was dry blended at 120 ° C. for preliminary kneading in a Banbury mixer for 4-5 minutes to produce a 0.35 mm thick sheet at a calendar roll temperature of 150 ° C.

The sheet was laminated in a plywood maker to prepare a sheet having a thickness of 1 mm, and then heat-treated at 110 ° C. for 15 hours and 30 hours in a roll state of about 50 m. The foams were then foamed in a 220 ° C. foam oven for 15 hours of aging and the outer part of the roll sheet was foamable, but the inner part of the sheet did not receive sufficient heat, making foaming difficult.

Comparative Example 2

A sheet was prepared in the same manner as in Comparative Example 1 except that the roll was aged for 30 hours. The inner part of the resulting sheet is foamable, but the outer sheet is heat-treated so that the foam is hard and some bubbles are generated.

Claims (7)

In the PVC resin foam composition, 0.05 to 5 PHR of the quaternary phosphonium salt represented by the following formula (1), epoxy resin 1 to 40 PHR, epoxy resin curing agent 0.1 to 20.0 PHR, foaming agent 1 to 40 PHR with respect to the PVC resin 100 PHR , PVC plastic foam composition comprising a plasticizer 1 to 100 PHR, and stabilizers 0.1 to 6 PHR. R represents an alkyl group or an aryl group having 1 to 20 carbon atoms, and four R's are the same kind or different kinds or combine with each other to form a ring, and X is a halogen, acetate, sulfate, diethyl phosphorodithioate anion. The group consisting of epoxidized soybean oil, epoxidized linseed oil, epoxy-alkyl ester, and bisphenol A epoxy resin, according to claim 1, wherein the epoxy equivalent weight is from 100 to 5000. PVC resin foam composition, characterized in that at least one selected from. The PVC resin foam composition according to claim 1, wherein the epoxy resin curing agent is selected from the group consisting of amine salts, organic acid anhydrides, polyvalent carboxylic acid metal salts, and monovalent or divalent metal oxides. 4. The amine salts according to claim 3, wherein the amine salts are diethyltriamine, benzyldimethylamine, triethylene tetramine, dicyandiamide, metaphenylenediamine, and the organic acid anhydrides are phthalic anhydride, maleic anhydride, dodecyl succinic anhydride, anhydride. Hexahydrophthalic acid, methylhexahydrophthalic anhydride, pyromellitic anhydride, methyltetrahydrophthalic anhydride, benzophenonetetracarboxylic acid, trimellitic anhydride, and the polyvalent carboxylic acid metal salts are selected from barium, cadmium, magnesium, zinc, calcium A divalent or trivalent metal salt to be selected, wherein the metal oxide is Li ⁺ , Na ⁺ , K ⁺ , Ca ²⁺ , Zn ²⁺ , Cd ²⁺ PVC resin foam composition characterized in that. The PVC resin foam composition according to claim 1, wherein the blowing agent is azodicarbonamide. The PVC resin according to claim 1, wherein the plasticizer is selected solely or more from the group consisting of dioctyl phthalate, diisodecyl phthalate, dioctyl adipate, dioctyl sebacate, trimellitic acid esters and polyesters. Foam composition. The PVC resin foam composition of claim 1, wherein the stabilizer is selected solely or more from the group consisting of Ba, Zn, Ca, Pb and Sn.