JPS63125554A - Polyvinyl chloride plastisol composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. for sealing materials, which is suitable for use in sealing the joints of the steel sheets of automobile bodies watertightly or airtightly by adding a specified nitrogen-contg. polyol and.or an OH- terminated polybutadiene to a compsn. consisting of a PVC resin, a plasticizer and a filler. CONSTITUTION:100pts.wt. PVC resin (A) for plastisol is blended with 8-175pts. wt. plasticizer (B) such as di(2-ethylhexyl) phthalate, a filler (C) such as calcium carbonate, CaO, clay, etc., and 1-10pts.wt. nitrogen-contg. polyol (D) of formula I (wherein R1, R2, R3 and R4) are each H or a 1-4C alkyl; n is 0-8) and/or polybutadiene (D) having OH groups at both terminals, composed of 1,2- or 1,4-bonded unit of formula II or III.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a polyvinyl chloride plastisol composition, and more particularly to a composition for a sealing material, which is particularly useful for watertightly and airtightly sealing joints of steel plates in automobile bodies.

PRIOR ART AND PROBLEMS TO BE SOLVED Conventionally, polyvinyl chloride plastisol compositions consisting of polyvinyl chloride resin, plasticizers, and fillers, for example, have been used in automobile assembly production lines to seal joints between steel plates in car bodies. It is being Such production lines typically press-form steel sheets, assemble the vehicle body, apply a sealant to the joints of the steel sheets, spray paint (usually an intermediate coat and a top coat), and then bake the paint film. In this case, the gelling or curing of the sealing material is performed simultaneously with the baking hardening of the coating film, and the conditions are generally 130
A time of 30 to 60 minutes at ~160°C has been employed.

However, after the paint film is baked, the two-coat paint film is often affected by the sealant and becomes discolored or cracked, resulting in poor surface finish or appearance. Furthermore, if the baking conditions are high temperature (160° C. or higher) and for a long time (30 minutes or longer), cracking of the coating film is expected, and these phenomena are often seen when there is a pause period in the manufacturing process line.

The present inventors have carried out extensive research in order to provide a polyvinyl chloride plus decyl composition for sealing materials that does not adversely affect the surface finish of the coating film after baking. I found out that
The present invention has now been completed.

Structure and effect of the invention That is, the present invention provides a polyvinyl chloride plastisol composition comprising a polyvinyl chloride resin, a plasticizer, and a filler, which has the formula: % formula % [wherein R,, R,, R, and R6 are the same or different from each other and are hydrogen or alkyl having 1 to 4 carbon atoms, and n is O to 8]; A vinyl plastisol composition is provided.

The polyvinyl chloride resin used in the present invention may be one for ordinary plastisols, and may be produced by emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, etc. of vinyl chloride alone or with other copolymerizable monomers. things may be adopted. Note that copolymers of vinyl chloride and other copolymerizable monomers are unstable in storage as plastisols and tend to increase in viscosity during storage, so vinyl chloride homopolymers are preferred.

Examples of the plasticizer in the present invention include di(2-ethylhexyl) phthalate, butylbenzyl phthalate, dioctyl phthalate (DOP), dinonyl phthalate,
Phthalate esters such as dioctyl phthalate, butyl phthalyl butyl glycol, dioctyl adipate,
Examples include aliphatic dibasic acid esters such as didecyl adipate and diotadyl sebacate, phosphoric acid esters such as tricresyl phosphate and trioctyl phosphate, and other epoxy plasticizers and polyester plasticizers. Use at least one IFU. Since such plasticizers affect the flow characteristics of plastisol and the physical properties of the cured product after gelation, the amount used is usually 80 to 175 parts per 100 parts (ffifft parts, the same shall apply hereinafter) of polyhinyl chloride resin. Although the proportion may be selected, a proportion of 100 to 150 parts is particularly preferable when used as a sealing material according to the present invention. ! At less than 150 parts, the tensile strength and elasticity increase, but the dischargeability decreases and workability becomes a problem.If it exceeds 150 parts, the viscosity decreases and sagging tends to occur.

Examples of the filler in the present invention include calcium carbonate (precipitated calcium carbonate, surface-treated with fatty acids or resin acids, or heavy calcium carbonate),
Calcium oxide, clay, talc, silica, etc. may be used, and calcium carbonate, particularly a combination of surface-treated precipitated calcium carbonate and ground calcium carbonate, is preferred.

By using such a filler, it is possible to adjust the flow characteristics and cured physical properties of the sealing material, and to reduce the cost.

The nitrogen-containing polyol in the present invention refers to an addition reaction product of polyethylene polyamine and alkylene ocquinde, and specific examples include C1l,
CIl 3110-CIl-CH, C11, -CIl
-0111] C113CI+.

C113C)l.

110-CIl-CIl,
CI, -C1-Of(I C113C1(3), etc. Also, the hydroxyl group-terminated polybutadiene used instead of or in combination with this nitrogen-containing polyol is a 1,2- An actuator consisting of a bond.

2 polybutadiene, or 1,4 polybutadiene consisting of 1,4-bonds represented by the formula with hydroxyl groups at both ends, with a number average molecular type of 500 to 5000 (preferably 500 to 20
00) may be used.

For example, as types 1 and 2, “Nl5” manufactured by Nippon Soda Co., Ltd.
SOPI3 G-1000J, "SOPI3 G-3000",
``Idemitsu PB4511'' manufactured by Idemitsu Oil Co., Ltd. is a 1.4 type.
TJ, [There is R-45MJ. These nitrogen-containing polyols and hydroxyl group-terminated polybutadiene are usually used at 1 to 10 parts per 100 parts of polyvinyl chloride resin.
Preferably, the amount may be selected within the range of 2 to 5 parts. If the amount is less than 1 part, the desired effect on preventing cracks in the coating film cannot be obtained, and if it exceeds 10 parts, the viscosity tends to increase and the dischargeability and shape retention tend to decrease.

The polyvinyl chloride plastisol composition according to the present invention contains polyvinyl chloride resin, a plasticizer, a filler, and a nitrogen-containing polyol or hydroxide in the above-mentioned predetermined proportions.

It is composed of syl group-terminated polybutadiene, and if necessary, it also contains conventional additives, such as dehydrochlorination reaction inhibiting stabilizers (metallic soap, organotin compounds, etc.), pigments (titanium white, etc.),
Adhesive agents and the like may be added as appropriate.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Examples 1 to 3 and Comparative Example 1 A sealing material composition is prepared by mixing and dispersing the raw materials in the proportions (parts) shown in Table 1 and defoaming them under reduced pressure.

Sealing and Painting After dispensing a bead of sealant onto the joint between the steel plates, smooth the surface with a brush and heat at 140°C for 30 minutes.
After applying a melamine alkyd white paint at a thickness of 30 to 40μ, baking is performed at 160°C for 60 minutes. The appearance of the resulting coating film was observed and the results are shown in Table 1.

○: No cracks or discoloration △・Small cracks ×: Large cracks Table 1 Note ■) Zeon 121, manufactured by Nippon Zeon ■) Zeon 103ZX, manufactured by Zeon ■) Hakuenka CCR, manufactured by Shiraishi Calcium Co. ■) Whiten B, manufactured by Shiraishi Calcium

Claims (1)

[Claims] 1. In a polyvinyl chloride plastisol composition comprising a polyvinyl chloride resin, a plasticizer, and a filler, the formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, R_1, R_2, R_3 and R_4 are the same or different and are hydrogen or alkyl having 1 to 4 carbon atoms, and n is 0 to 8.] A polychlorinated polychloride characterized by adding a nitrogen-containing polyol and/or a hydroxyl group-terminated polybutadiene. Vinyl plastisol composition. 2. Addition amount of nitrogen-containing polyol and/or hydroxyl group-terminated polybutadiene is 10% of polyvinyl chloride resin
The composition according to item 1 above, wherein the amount is 1 to 10 parts by weight relative to 0 parts by weight.