JPH04363380A - Mastic adhesive - Google Patents

Abstract

PURPOSE:To obtain a mastic adhesive having stable bond strength to various steel plates for body panel by blending a base component composed of synthetic rubber, PVC, etc., with a mixture of epoxy resin and polyamidoamine as an adherent agent. CONSTITUTION:(A) 100 pts.wt. of base component composed of (i) partially crosslinked or uncrosslinked synthetic rubber, (ii) PVS, (iii) a plasticizer and (iv) a filer is blended with (B) 1-10 pts.wt. (preferably 3-8 pts.wt.) mixture of an epoxy resin having >=60 deg.C softening point and a polyamidoamine in an equivalent ratio of 6:4 to 4:6 as an adherent agent to give the objective adhesive.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a mastic adhesive, more specifically, used for adhering car body panels, and by blending a specific adhesive mixture, it provides stable adhesion to various steel plates used as car body panels. Concerning mastic adhesives with strength.

0002

[Prior Art and Problems to be Solved by the Invention] Mastic adhesives are used in various parts, such as bonnets, roofs, trunks, doors, and other outer panels and reinforcing inner panels, in the assembly method of automobile bodies. For example, partially cross-linked or uncross-linked synthetic rubber,
Those consisting of polyvinyl chloride, plasticizers, adhesives and fillers are known. Incidentally, recently, the trend toward longer life, that is, achieving corrosion protection, has been gaining momentum as an important technical issue in the automobile industry, and in order to improve the corrosion resistance of the steel plate used for the above-mentioned car body panels, conventional SP
From C steel sheets, electrogalvanized steel sheets, hot-dip galvanized steel sheets, organic surface-treated steel sheets, alloyed hot-dip galvanized steel sheets (G
A) Various corrosion-resistant steel sheets such as Zn-Ni alloy plated steel sheets are being adopted. However, the mastic adhesives mentioned above use blocked polyisocyanates, polyamide resins, etc. as adhesives, but they have excellent adhesion to ordinary cold-worked steel sheets, electrogalvanized steel sheets, or hot-dip galvanized steel sheets. However, the adhesive strength was inferior to other corrosion-resistant steel plates.

0003

[Means for Solving the Problems] The present inventors have carried out extensive research in order to provide a mastic adhesive that exhibits comparable and stable adhesion to various steel plates, and have found the structure of the mastic adhesive described above. The inventors have discovered that the desired mastic adhesive can be obtained by adding a mixture of an epoxy resin and polyamide amine, which is solid at room temperature, as an adhesive to the part, and have completed the present invention.

That is, the present invention provides a base component consisting of partially crosslinked or uncrosslinked synthetic rubber, polyvinyl chloride, a plasticizer, and a filler, and a mixture of an epoxy resin with a softening point of 60° C. or higher and polyamide amine as an adhesive. The present invention provides a mastic adhesive characterized by containing the following.

The synthetic rubber in the present invention includes partially crosslinked or uncrosslinked synthetic rubbers, and these partially crosslinked and uncrosslinked types can be used alone, but preferably they are used in combination (usually, The mixing ratio of the partially crosslinked type and the uncrosslinked type is selected at a ratio of 6:4 to 9:1). Examples of the partially crosslinked synthetic rubber include acrylonitrile-isoprene copolymer rubber (NIR), acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), butadiene rubber, isoprene rubber, etc. It is a diene rubber that has been partially heat-crosslinked in advance using a crosslinking agent such as divinylbenzene or sulfur. Such partially crosslinked synthetic rubbers are commercially available from Nippon Gosei Rubber Co., Ltd., Nippon Zeon Co., Ltd., and others. Desirable partially crosslinked synthetic rubbers include NBR and SBR synthetic rubbers. Furthermore, as the uncrosslinked synthetic rubber, acrylonitrile-isoprene copolymer rubber (
NIR), acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SB
R), butadiene rubber, isoprene rubber, etc. Synthetic rubbers that are not crosslinked at all, especially those with a Mooney viscosity (according to the JISK-6300 standard) of 30 to 5
A range of 0 is desirable. More preferably, it is an uncrosslinked synthetic rubber of NBR.

[0006] As the polyvinyl chloride used in the present invention,
Ordinary plastisol materials produced by emulsion polymerization, suspension polymerization, bulk polymerization, solution polymerization, etc. may be used. The amount used may be selected in the range of 2 to 20% (wt% based on the total amount of mastic adhesive, hereinafter the same), preferably 5 to 15%. If it exceeds 20%, the steel plate tends to rust due to dehydrochlorination of polyvinyl chloride during heat curing or over time, and if it is less than 2%, the adhesive strength to oil surfaces decreases.

The plasticizer used in the present invention is one that swells and dissolves partially crosslinked or uncrosslinked synthetic rubber and polyvinyl chloride, and specifically includes phthalate esters, petroleum distillation products, etc. DOP, DBP, DIDP,
Examples include BBP, DINP, DHP, and higher alcohol phthalates. The amount used is normally selected within the range of 20 to 60%, preferably 40 to 60%. If it exceeds 60%, the viscosity will drop to 500 poise or less and shape retention will be lost, and if it is less than 20%, the viscosity will become high and the dischargeability with a pressure pump will decrease, causing difficulties in operation.

The filler used in the present invention is necessary for adjusting flow characteristics and physical properties, and includes calcium carbonate, clay, talc, silica powder, cellulose powder, resin powder, metal powder, etc. . The amount used is usually 30~
It may be selected in the range of 60%, preferably 35 to 55%.

The epoxy resin used in the present invention has a softening point of 6
It is solid at room temperature of 0°C or higher, preferably 90 to 150°C, and examples include glycidyl ether type, glycidyl ester type, glycidylamine type, aliphatic epoxide type, and alicyclic epoxide type. In particular, glycidyl ether type epoxy resins having an epoxy equivalent of 400 to 3000, preferably 800 to 2500 may be used, such as "Epicoat 10" manufactured by Yuka Ciel Epoxy Co., Ltd.
01'', ``1004'', ``1007'', etc. If the adhesive has a softening point of less than 60° C. or is liquid at room temperature, it will undergo a curing reaction with the polyamide amine, so the viscosity of the adhesive tends to increase or gel during the standing period, which is undesirable.

[0010] Furthermore, the polyamide amine to be mixed with the epoxy resin refers to a polyamide amine that has a plurality of active amino groups and one or more amide groups in its molecule and is usually used as a curing agent for epoxy resins. , aliphatic (dimer acid)
A condensation reaction product of polyamine and polyamine is used. For example, Cielex Chemical Co., Ltd., Dainippon Ink Chemical Co., Ltd.
It is commercially available from Fuji Kasei Kogyo Co., Ltd., Sanyo Kasei Kogyo Co., Ltd., Henkel Hakusui Co., Ltd., etc. The mixing ratio of the epoxy resin and polyamidoamine is usually selected to be an equivalent ratio of 6:4 to 4:6, preferably an equivalent ratio to an excess equivalent of polyamidoamine. The amount of such a mixture used is usually 10% of the base component consisting of the partially crosslinked to uncrosslinked synthetic rubber, polyvinyl chloride, plasticizer and filler.
The amount may be selected within the range of 1 to 10 parts, preferably 3 to 8 parts, relative to 0 parts (by weight, hereinafter the same). If it is less than 1 part, it will not be possible to exhibit stable adhesion to various desired steel plates, and if it exceeds 10 parts, the cured product of the adhesive will become hard, and if it is less than 3 parts, the adhesive strength will tend to decrease. be.

The mastic adhesive according to the present invention is composed of a mixture of a predetermined amount of an epoxy resin having a softening point of 60° C. or higher and a polyamide amine to the above-mentioned base component, and further contains pigments and aging as necessary. Inhibitor (BHT etc.)
, a crosslinking agent (zinc white, sulfur, divinylbenzene, etc.) may be added in small amounts.

0012

According to the mastic adhesive of the present invention having the above-described structure, it can have stable adhesion to various steel plates of vehicle body panels, and can contribute to achieving the important technical problem of corrosion prevention.

[0013]

[Examples] Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Examples 1 to 6 and Comparative Examples 1 to 2 (1) Preparation of base component Partially crosslinked synthetic rubber [NBR manufactured by Nippon Zeon Co., Ltd.
Nipol 214] 6 parts and uncrosslinked synthetic rubber [NBR, JSR N234L manufactured by Japan Synthetic Rubber Co., Ltd.] 2
This was mixed and dissolved in 25 parts of plasticizer (DOP) using a strong kneader, and then polyvinyl chloride [Kaneka P, manufactured by Kanekabuchi Chemical Co., Ltd.]
5 parts of SH-10] and 35 parts of a filler (calcium carbonate) were added and uniformly dispersed. (2) Preparation of Mastic Adhesive A mastic adhesive is obtained by blending the components shown in Table 1 below with 100 parts of the base component in (1) above. (3) Adhesion test Two of each of the five types of steel plates were prepared as test steel plates (the surface of the steel plate was wiped only with a waste cloth), mastic adhesive was applied to the adhesive surface, and the adhesive was heated at 165°C for 25 minutes to harden and bond. , the shear adhesive strength (Kg·f/cm2) is measured. The results are shown in Table 2.

[0014]

[Table 1] In Table 1, Note 1: Product name manufactured by Yuka Ciel Epoxy Co., Ltd. Note 2: Product name manufactured by Cielex Chemical Co., Ltd. Note 3: Product name manufactured by Dainippon Ink and Chemicals Co., Ltd. Note 4: Product name manufactured by Henkel Hakusui Co., Ltd. Note 5: Barlock DB manufactured by Dainippon Ink and Chemicals Co., Ltd.
555

[0015]

[Table 2]

Claims (2)

[Claims] [Claim 1] A mixture of an epoxy resin with a softening point of 60°C or higher and polyamide amine is blended as an adhesive into a base component consisting of partially crosslinked or uncrosslinked synthetic rubber, polyvinyl chloride, a plasticizer, and a filler. A mastic adhesive characterized by: 2. The mastic adhesive according to claim 1, wherein 1 to 10 parts by weight of a mixture of epoxy resin and polyamide amine in an equivalent ratio of 6:4 to 4:6 is blended to 100 parts by weight of the base component.