JPS58204075A - Preparation of foamable hot-melt adhesive - Google Patents

Abstract

PURPOSE:To obtain the titled adhesive forming a foam by heating, by molding a plastisol comprising a vinyl chloride-based paste resin and a heat-decomposable foaming agent dispersed in a plasticizer into sheets, etc. in a state of semi- gelation. CONSTITUTION:A vinyl chloride-based paste resin (e.g., vinyl chloride/vinyl acetate copolymer paste resin) and a heat-decomposable foaming agent (e.g., sodium bicarbonate) are dispersed in a polyvinyl chloride plasticizer such as dibutyl phthalate or tricresyl phosphate to prepare a plastisol in the liq. form at ordinary temp. At nearly the same time when brought to a semi-gelation state on standing at ordinary temp. or by heating, said plastisol is molded into granules, pellets, or sheets and brought to a semi-gelation state which is tack- free at ordinary temp., yielding the intended foamable hot-melt adhesive. Said adhesive is well suited to adhesives for adherends with rough surfaces.

Description

Detailed Description of the Invention: From Takumai, Honmelt adhesive is a paste resin made of ethylene-vinyl acetate, EVA, or polyamide on both sides, and a sticky layer of various resins such as rosin and petroleum resin. Adding agents and modifiers such as wax, paraffin, etc. with low bath melting and continuous solidification are mixed by melting in a hot bath. It is impossible to produce a foamable hot melt adhesive that forms a foam after being heated at 5 temperature because it will foam during the production of hot melt adhesive #7.
It was a T rudder.

An object of the present invention is to provide a method for producing a foaming hot melt adhesive that is in an unfoamed solid state and forms a foam after heating.

In the present invention, during OJ production for high-density vinyl, liquid Glastisol is left at room temperature or heated to a semi-gelled state by dispersing a vinyl chloride paste resin and a thermally decomposable blowing agent into a semi-gelled state. It is then processed into granules, pellets, or sheets, and is made into a semi-gelatinous state with no stickiness on the surface at room temperature.

As a plastic agent for vinyl chloride used in the present invention &, 1
.

DOP, DBP, heptatalic acid esters, TCP (
Phosphate esters such as tricresyl phosphate), DOA
In addition to adipates such as (dioctyl adipate), chlorinated paraffin threads, allyl ester thermosetting 6T plastics such as DAP (diallyl phthalate) monomer, acrylic esters, unsaturated polyesters, etc., it also serves as a stabilizer. Any known plasticizer that is compatible with vinyl chloride resin when heated, such as epoxy resin, may be used. Vinyl chloride paste resin is a finely powdered vinyl chloride resin obtained by emulsion polymerization of vinyl chloride monomer alone and copolymerized vinyl acetate monomer, etc.
31, 135, 400
) and other known vinyl chloride base resins may be used; however, if dense layer properties, low-temperature bath melting, and low-temperature foam molding are required, vinyl chloride-vinyl acetate copolymers or polar groups such as carboxyl groups may be introduced. It is better to mix paste resin. Thermal decomposition type blowing agents include well-known inorganic foams such as sodium carbonate, nitroso compounds, azo compounds such as azodicarbonamide and azobis-isobutyronitrile, and sulfonyl hydrazides such as benzene sulfonyl hydrazide. Among these, 1-zo compounds are commonly used, although broods made of finely ground wood can be used. Other stabilizers for vinyl chloride are included in Gufstesol, and composite stabilizers such as for soap, non-alpha acid salts, organic tin compounds, calcium-zinc powder, cadmium + Ik bale combination, cadmium-barium thread, etc. There are many other drugs available, but liquid composite drugs are preferred. In addition, if necessary, inorganic materials such as charcoal and silica powder, and other materials can also be added to the shield.

Due to the nature of plastisol, (a) at room temperature, the coating of resin particles is slightly solvated by oJ plastic MIJ, but the particles move freely relative to each other and flow as a viscous sol. However, (b) It is highly compatible with resin and consists of a low molecular weight = r In plastics, even if the temperature of the material increases over time, and even in the case of ordinary plastic wholesalers, the resin The swelling of the particles has progressed to a considerable extent, and the particles loosely meet each other in the bath on their surface layers and become solidified, and the fluidity is no longer achieved, but the center of the particles remains ungelled, and the physical strength of the gel is poor. , the surface is translucent without gloss (semi-gelled state).

When further heated to a high temperature, (c) the entire resin particle completely gels and swells to the core, melts and flows, and the solvated vinyl chloride molecules cause active micro-Brownian motion.
The molecular entanglement between the particles becomes stronger, the physical strength reaches its maximum, and the surface becomes glossy and transparent (completely molten state). Next, (d) in a completely molten state, the thermally decomposable blowing agent decomposes to generate gas and form a foam (foam forming state). hand,
(a) Plastisol, which is in a fluid state at room temperature, is processed into (b) semi-gelled state into granules, pellets, or sheets. C) It exhibits its function as an adhesive through a completely melted state and (d) a foamed state.

In order to bring the liquid plastisol, which becomes the ammonium hydroxide in the present invention, into a semi-gelling state, a heating method is usually adopted from the viewpoint of workability. It is safe to carry out melting in a gold bath or at a temperature below the decomposition temperature of the foaming agent and above the gelling temperature.
It can be manufactured in a few minutes at a temperature of 50 to 100° C., although it varies depending on the hammering and blending of the plastic, the cutting and blending of the base resin, the 4*fA of the foaming agent, and the projection.

For example, when it is granulated, it is placed in warm water. If it is desired to form a sheet, it may be coated on a release paper using a knife coater or a roll coater and passed through a hot JJL dry pulse finger.

Alternatively, it can be formed into any shape by filling it widely on a hot plate, processing it into a semi-gelled state, cutting it, or crushing it.

The foamable hot-melt adhesive prepared in this manner exhibits its function as a foaming adhesive or adhesive when heated to the melting temperature of the pre-metal bath and above the decomposition temperature of the foaming agent. It performs its functions within the range of. Then, Ichikawa applied it as a temporary adhesion body consisting of unevenness +[+1, honeycomb #jt, as a sealant to the skin of a dead body, and as a sealing material for spot bath contact parts, etc.

Next, the present invention will be explained with reference to all embodiments.

Example l l1g1 Table Gelastesol combination However, 1. Vinyl chloride base: 1 Torezin (Nippon Zeon) 2. Sobi Vinyl Acetate Kyoden Paste Resin (Nippon Zeon) 8. Calhokifur Kijin Paste Resin (1 Zeon) 4.2 Ethylhexyl phthalate (IJJM#lI, Seed water chemistry) 6 Diptyl phthalate (IT plastic ilL H water chemistry) 6
, 7 Zojiki Rubonamide Itocho rk Ha IJ (A 4+l
7. Apply the gelastesol formulation shown in Table 1 to approximately au f lcd (thickness 0) on release paper using a knife coater.
．． 3sa+), dried with hot air at 80'C for 3 minutes, and then left to normal humidity with N,i! 41 t
The hot melt adhesive of the present invention was prepared by winding it up as it was.

Next, the meshed cement asbestos board surface ■ and the unevenness i0.
2 to 0.3 tone embossed copper foil, □ sandwich the foamable hot melt adhesive (:, /-1),
The layers were dried for 5 minutes in a hot air dryer at 200°C.

It was confirmed that there was no adhesion after the mold layer processing, and that the uneven parts were also treated with the original GTL light material.

Patent applicant: Aikanigyo Co., Ltd.

Claims (1)

[Claims] 1. 7 Lastisol, which is liquid at room temperature and is made by dispersing a vinyl chloride paste resin and a thermally decomposable blowing agent in a plasticizer for vinyl chloride, is left at room temperature or heated to a semi-gelled state. ,
M manufacturing method for foamable hot melt adhesives, which involves processing them into granules, pellets, or sheets before and after molding, and making them into a semi-gelled state to the extent that they are not sticky at room temperature. 2. The method for producing a foamable hot melt adhesive according to claim 1, wherein the vinyl chloride thread paste resin contains a resin into which a polar group such as a vinyl acetate group or a carboxyl group has been introduced.