JP5417209B2 - Mastic adhesive - Google Patents

Description

  The present invention relates to a mastic adhesive and its bonding method, and in particular, a curable composition that exhibits excellent elongation and adhesive strength after curing and provides a sufficient foaming ratio when applied to a complete knockdown line, and its It relates to the bonding method.

  Conventionally, a mastic adhesive containing a diene-based synthetic rubber has been frequently used for adhesion of vehicle body panels (Patent Documents 1 and 2). In recent years, a line for complete knockdown (hereinafter referred to as CKD) for transporting body panel parts after assembly and bonding to the body in the field has increased. Further, with the integration of the mastic adhesive and the spot sealer, a foam type mastic adhesive is required.

  However, in an adhesive in which a foaming agent is simply added to the above-mentioned adhesive, the organic peroxide in the adhesive is deactivated or the adhesive absorbs water during the standing period after transportation. Sufficient cross-linking occurred, and as a result, the adhesive could not hold bubbles due to the foaming agent, resulting in a decrease in the expansion ratio. Moreover, the adhesive strength was also lowered due to insufficient crosslinking of the rubber component.

JP 2007-302755 A Japanese Patent Laid-Open No. 10-25458

  It is an object of the present invention to provide a curable composition that exhibits excellent elongation and adhesive strength after curing and can provide a sufficient expansion ratio after CKD transportation, and an adhesion method thereof.

The inventors of the present invention provide a mastic adhesive containing a diene rubber component and a quinonedioxime crosslinking agent, and containing the quinonedioxime crosslinking agent in an amount of 16 to 40 parts by weight with respect to 100 parts by weight of the diene rubber component. As a result, the present invention has been completed.
That is, the following preferred embodiments are included in the present invention.
[1] a) Rubber component comprising uncrosslinked synthetic rubber and / or partially crosslinked synthetic rubber,
A mastic adhesive comprising b) a quinonedioxime vulcanizing agent and c) a foaming agent and containing 16 to 40 parts by weight of the quinonedioxime vulcanizing agent b) with respect to 100 parts by weight of the rubber component a).
[2] The mastic adhesive according to [1], containing 16 to 35 parts by weight of quinonedioxime vulcanizing agent b) per 100 parts by weight of rubber component a).
[3] The mastic adhesive according to [1] or [2], wherein the uncrosslinked synthetic rubber is butadiene rubber.
[4] The mastic adhesive according to any one of [1] to [3], wherein the partially crosslinked synthetic rubber is a styrene-butadiene copolymer rubber.
[5] The mastic adhesive according to any one of [1] to [4] is discharged from a hose tip nozzle of a pressure feed pump to an adhesion portion between an outer panel and an inner panel of a vehicle body and assembled and bonded. A body panel bonding method.
[6] The bonding method according to [5], which is applied to a complete knockdown line.

  The curable composition of the present invention can be suitably used as a mastic adhesive because a sufficient expansion ratio and adhesive strength can be obtained even after CKD transport.

Embodiments of the present invention will be described below.
The mastic adhesive of the present invention (hereinafter referred to as adhesive) comprises a rubber component a) composed of uncrosslinked synthetic rubber and / or partially crosslinked synthetic rubber.

In the present invention, the uncrosslinked synthetic rubber refers to a rubber having a carbon double bond that is not crosslinked in the main chain. Synthetic rubbers that can be used for the uncrosslinked synthetic rubber of the present invention include acrylonitrile-isoprene copolymer rubber (NIR), acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), butadiene. Examples thereof include diene rubbers having a carbon unsaturated carbon bond in the main chain, such as rubber and isoprene rubber, and one or more of these may be used. Of these, butadiene rubber is preferred. An uncrosslinked synthetic rubber having a Mooney viscosity (in accordance with JIS K-6300 standard) of 30 to 50 is particularly suitable.
As a typical commercial item of uncrosslinked type synthetic rubber, butadiene rubber BR-150 (made by Ube Industries, Ltd.) is mentioned, for example.

In the present invention, the partially crosslinked synthetic rubber refers to a partially crosslinked synthetic rubber. In the present invention, the partial crosslinking means a rubber obtained by previously crosslinking the uncrosslinked rubber with a crosslinking agent.
Synthetic rubbers that can be used in the partially crosslinked synthetic rubber of the present invention include acrylonitrile-isoprene copolymer rubber (NIR), acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), and butadiene. Examples thereof include rubber and isoprene rubber, and one or more of these may be used. Among these, NBR or SBR is preferable.
Typical commercially available partially crosslinked synthetic rubbers include, for example, NBR N202S (manufactured by JSR Corporation), SBR # 1009 (manufactured by ISP Elastmer), and the like.

In the adhesive of the present invention, the rubber component a) is preferably 4% by weight or more, more preferably 6% by weight or more based on the total weight of the adhesive in terms of shape retention and sag. It is. Also, the adhesive according to the present invention contains the rubber component a) preferably in an amount of 30% by weight or less, more preferably in an amount of 20% by weight or less based on the total weight of the adhesive in terms of dischargeability.
The rubber component a) is preferably an uncrosslinked synthetic rubber in terms of foaming ratio and elongation rate, preferably 20% by weight or more, more preferably 30% by weight based on the total weight of the rubber component a). % Or more. The rubber component a) is preferably an uncrosslinked synthetic rubber in terms of shape retention and sag, preferably 70% by weight or less, more preferably, based on the total weight of the rubber component a). 60% by weight or less is contained.
Further, the rubber component a) includes a partially crosslinked synthetic rubber, preferably 30% by weight or more, more preferably 40%, based on the total weight of the rubber component a) in terms of shape retention and sag. More than wt% is included. The rubber component a) is preferably partially crosslinked synthetic rubber in terms of expansion ratio and elongation rate, preferably 80% by weight or less, more preferably 70% by weight based on the total weight of the rubber component a). % Or less is included.

The adhesive of the present invention comprises a quinonedioxime crosslinking agent b) in addition to the rubber component a).
Examples of the quinonedioxime crosslinking agent that can be used in the present invention include p-quinonedioxime, dibenzoyl-p-quinonedioxime, and p-quinonedioxime is preferred.
In the adhesive of the present invention, the quinonedioxime-based crosslinking agent is preferably 16% by weight or more, based on the total weight of the rubber component a) in terms of CKD characteristics (adhesive strength / foaming ratio after transportation), More preferably, it is contained in an amount of 18% by weight or more. In the adhesive of the present invention, a quinonedioxime crosslinking agent is preferably 40% by weight or less, more preferably 35% by weight or less, in terms of elongation, based on the total weight of the rubber component a). included.
As a typical commercial item of a quinone dioxime type | system | group crosslinking agent, Ouchi Shinsei Chemical Co., Ltd. Barnock GM is mentioned, for example.

The adhesive of the present invention comprises a foaming agent c) in addition to the components a) and b).
Examples of the foaming agent that can be used in the present invention include pyrolytic organic foaming agents such as azodicarbonamide, N, N′-dinitrosopentamethylenetetramine, 4,4′-oxybis (benzenesulfonylhydrazide), thermoplastic / thermal Examples include a microballoon foaming agent in which a heat-expandable substance is encapsulated inside a polymer core made of a curable resin, and azodicarbonamide is particularly preferable.
The adhesive of the present invention preferably comprises 0.15% by weight or more, more preferably 0.2% by weight or more of a foaming agent based on the total weight of the adhesive. The adhesive of the present invention preferably comprises 2% by weight or less, more preferably 1.5% by weight or less of a foaming agent based on the total weight of the adhesive. When the adhesive according to the present invention contains a foaming agent within the above range, it is advantageous from the viewpoint of sealing properties after heating.
As a typical commercial item of a foaming agent, Otsuka Chemical Co., Ltd. uniform AZ is mentioned, for example.

  In addition to the above components a), b) and c), the adhesive of the present invention is optionally provided with a plasticizer, a filler, an adhesion-imparting agent, a moisture curable resin, an anti-aging agent (such as BHT), and a crosslink. Accelerators (such as di-2-benzothiazolyl disulfide), curing accelerators (such as dibutyltin dilaurate, lead octylate, bismuth octylate), silane coupling agents, dehydrating agents (such as calcium oxide), solvents (naphtha, High boiling hydrocarbon solvents such as paraffin) and the like.

  Examples of the plasticizer that can be used in the present invention are those that swell and dissolve uncrosslinked synthetic rubber and partially crosslinked synthetic rubber. Specifically, phthalic acid esters and petroleum fractionated products such as DOP, DBP, DIDP, BBP, DINP, DHP, higher alcohol phthalate and the like can be mentioned. The adhesive of the present invention may contain 20% to 50% by weight, more preferably 30% to 45% by weight of a plasticizer, based on the total weight of the adhesive.

  The filler that can be 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, and the like. The adhesive of the present invention may contain 30% to 50% by weight, more preferably 35% to 45% by weight filler, based on the total weight of the adhesive.

  Examples of the adhesion-imparting agent that can be used in the present invention include a thermosetting material and its latent curing agent, a phenol resin, and a polyamide resin.

The thermosetting material may be selected from the following groups (i) to (iv), for example.
(I) Polyol [for example, polyoxyalkylene polyol (PPG), polyether polyol modified, polyether polyol containing polytetramethylene ether glycol; condensed polyester polyol, lactone polyester polyol, polyester polyol containing polycarbonate diol; other poly Budadiene polyol, polyolefin polyol, etc.] and excess polyisocyanate compound [eg trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate , Dodecamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,6- Xanthane diisocyanate (HDI), 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4′-methylene bis (cyclohexyl isocyanate), 4,4′-methylene bis (cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, Methyl 2,6-cyclohexane diisocyanate, 1,4-bis (isocyanate methyl) cyclohexane, 1,3-bis (isocyanate methyl) cyclohexane, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1, 5-naphthalene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), crude MDI, 2,4- or 2,6-tolylene diisocyanate 4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 1,3- or 1,4-xylylene diisocyanate, ω, ω′-diisocyanate-1,4-diethylbenzene, etc.] To obtain a terminal NCO-containing urethane prepolymer, which includes suitable blocking agents (eg, alcohols such as methanol, ethanol, propanol, butanol, isobutanol; phenols, cresols, xylenols, p-nitrophenols, alkylphenols, etc.) Phenols; active methylene compounds such as methyl malonate, dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, acetylacetone; acetamide, acrylamide, acetanilide, etc. Amides; acid imides such as succinimide and maleic imide; imidazoles such as 2-ethylimidazole and 2-ethyl-4-methylimidazole; lactams such as 2-pyrrolidone and ε-caprolactam; acetoxime, methylethylketoxime, A blocked urethane prepolymer obtained by reacting a ketone or aldehyde oxime such as cyclohexanone oxime, acetoaldoxime, etc .; other ethyleneimine, bisulfite, etc.) to block free NCO;

(Ii) a blocked polyisocyanate compound obtained by blocking free NCO of the polyisocyanate compound with the blocking agent;

(Iii) Polyhydroxy compounds [for example, polyalkylene glycol (polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, etc.); hexylene glycol, butylene glycol, propylene glycol, ethylene glycol, neopentyl glycol, triethylene glycol, pentanediol, hexanetriol , An aliphatic polyvalent hydroxy compound such as glycerol] and an epihalohydrin, and / or an alkylene oxide-modified glycidyl ether-type epoxy resin; and / or

(Iv) A polyether polyol (for example, polyoxyalkylene polyol, polyether polyol modified product, polytetramethylene ether glycol) is reacted with an excess of a polyisocyanate compound to obtain a terminal NCO-containing urethane prepolymer. A polyether urethane-modified epoxy resin obtained by reacting an epoxy resin having at least one hydroxyl group (for example, diglycidyl ether of bisphenol A, diglycidyl ether of aliphatic polyhydric alcohol).

As the latent curing agent, known ones may be used as appropriate according to the type of the thermosetting material, and for example, selected from the following groups (A) to (C).
(A) Those which can be activated at a temperature of 60 ° C. or more to react with an isocyanate group or a glycidyl group, such as adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, 1,3-bis (hydrazinocarboethyl) -5 Dihydrazide compounds such as isopropyl hydantoin, eicosanedioic acid dihydrazide, hydroquinone diglycolic acid dihydrazide, resorcinol diglycolic acid dihydrazide, 4,4'-ethylidenebisphenol diglycolic acid dihydrazide; dicyandiamide; 4,4'-diaminodiphenyl sulfone; imidazole, 2 Imidazole compounds such as n-heptanedecylimidazole; melamine; benzoguanamine; N, N′-dialkylurea compound; N, N′-dialkylthiourea compound; Room temperature solid polyamines having a melting point of 60 ° C. or higher, such as phenylmethane, diaminobiphenyl, diaminophenyl, phenylenediamine, tolylenediamine, dodecanediamine, decanediamine, octanediamine, tetradecanediamine, hexadecanediamine, hydrazide polyamines;

(B) Aliphatic polyamine (a) (for example, dimethylaminopropylamine, diethylaminopropylamine, dipropylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, dipropylaminoethylamine, dibutyl as polyamine-based modifying compounds Aminoethylamine, trimethylhexamethylenediamine, diaminopropane, etc.) and a cyclic amine or aromatic polyamine (b) having at least one NH ₂ or NH group (for example, metaxylylenediamine, 1,3-bis (aminomethyl)) Cyclohexane, isophoronediamine, menthanediamine, diaminocyclohexane, phenylenediamine, toluylenediamine, xylylenediamine, diaminodipheny Polyamines and monoamines such as rumethane, diaminodiphenylsulfone, piperazine, N-aminoethylpiperazine, benzylamine, cyclohexylamine) and diisocyanate compounds (c) (for example, isophorone diisocyanate, metaxylylene diisocyanate, 1,3-bis (isocyanatomethyl) ) Cyclohexane, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, 1,5-naphthylene diisocyanate, 1,4-phenylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 2,2′-dimethyldiphenylmethane -4,4'-diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, etc.) (A), amine (b) and epoxide compound (d) (polyphenols such as bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, catechol, resorcin, trihydroxybiphenyl, benzophenone, hydroquinone, tetramethylbisphenol A, etc. And glycidyl ether obtained by reacting epichlorohydrin with polyglycidyl ether obtained by reacting aliphatic polyhydric alcohols such as glycerin, neopentyl glycol, ethylene glycol and polyethylene glycol with epichlorohydrin; p-oxybenzoic acid and oxynaphthoic acid Glycidyl ether ester obtained by reacting hydroxycarboxylic acid such as epichlorohydrin; phthalic acid, isophthalic acid, tetrahydrophthalic acid, ene Polyglycidyl ester derived from polycarboxylic acid such as methylenetetrahydrophthalic acid, trimellitic acid, polymerized fatty acid; glycidylaminoglycidyl ether derived from aminophenol, aminoalkylphenol; glycidylaminoglycidyl ester derived from aminobenzoic acid; Glycidylamine derived from aniline, toluidine, tribromoaniline, xylylenediamine, 4,4′-diaminodiphenylmethane; epoxidized polyolefin, glycidylhydantoin, glycidylalkylhydantoin, triglycidylcyanurate, butylglycidyl ether, phenylglycidyl ether, Monoepoxides such as alkylphenyl glycidyl ether, glycidyl benzoate, styrene oxide, etc. Reaction products;

(C) As another polyamine-based modifying compound, one or more selected from the group of the above-mentioned aliphatic polyamine, cyclic structure amine or aromatic polyamine and an epoxy compound (for example, one epoxy group in the molecule) Or an addition reaction product of bisphenol-type epoxy resin, novolac-type epoxy resin, polyester-type epoxy resin, polyether-type epoxy resin, or the like, having a phenol compound (for example, phenol resin, resole novolak resin) and / or poly Inactivated by reacting a carboxylic acid compound (for example, adipic acid, sebacic acid, dodecanoic acid, azelaic acid, etc.) and masking the amino group.

In the present invention, the above-mentioned adhesion promoter may be used alone or in combination of two or more.
The adhesive of the present invention may preferably contain 2% by weight or more, more preferably 3% by weight or more of an adhesion-imparting agent in terms of increasing the adhesive strength based on the total weight of the adhesive. In addition, the adhesive of the present invention may contain an adhesion-imparting agent that is preferably 15% by weight or less, more preferably 10% by weight or less from the viewpoint of elongation based on the total weight of the adhesive.

（式中、Ｒは炭素数１〜４の低級アルキル、シクロペンチル、シクロヘキシル、ビニル、アリル、フェニル、トリル、ナフチル、２−フェニルエチル等；Ｘは加水分解可能な基であって、アルコキシ、アシロキシ、ケトオキシム、アルケニルオキシ、アルキルもしくはシクロアルキル置換アミノ、アルキルもしくはシクロアルキル置換アミノオキシ、Ｎ−メチルアセトアミド、Ｎ−エチルアセトアミド、Ｎ−メチルベンズアミド等；およびｎは０〜２である）の基を含有するものを指称し、具体的には、（ａ）分子両末端にアリル基を含有するポリオキシポリアルキレンポリエーテルに、加水分解性シリル基とＳＨ基またはＳｉに直接結合した水素とを含有する化合物を付加反応させたもの；（ｂ）エポキシ化合物に、該エポキシ基と反応しうる基および加水分解性シリル基を分子中に含有する化合物を付加反応させたもの；（ｃ）ポリイソシアネート化合物に、該イソシアネート基と反応しうる基および加水分解性シリル基を分子中に含有する化合物を付加反応させたもの；および（ｄ）有機ポリヒドロキシ化合物または有機ポリチオール化合物に、分子中にイソシアネート基および加水分解性シリル基を含有する化合物を付加反応させたもの等が挙げられる。
本発明の接着剤は、耐高圧シャワー性が良好で、かつ焼き付け後の密着性がバランスよく満足できることから、該接着剤全重量を基準として、好適には０．５重量％〜１０重量％、より好適には３重量％〜５重量％の湿気硬化性樹脂を含んでよい。 The moisture curable resin that can be used in the present invention includes at least two hydrolyzable silyl groups in the molecule, for example, the formula:

(Wherein R is a lower alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl, vinyl, allyl, phenyl, tolyl, naphthyl, 2-phenylethyl and the like; X is a hydrolyzable group, and alkoxy, acyloxy, Ketoxime, alkenyloxy, alkyl or cycloalkyl substituted amino, alkyl or cycloalkyl substituted aminooxy, N-methylacetamide, N-ethylacetamide, N-methylbenzamide and the like; and n is 0 to 2). Specifically, (a) a compound containing a hydrolyzable silyl group and an SH group or hydrogen directly bonded to Si to a polyoxypolyalkylene polyether containing an allyl group at both ends of the molecule (B) an epoxy compound reacted with the epoxy group And (c) a polyisocyanate compound containing a group capable of reacting with the isocyanate group and a hydrolyzable silyl group in the molecule. Examples include compounds obtained by addition reaction of compounds; and (d) organic polyhydroxy compounds or organic polythiol compounds obtained by addition reaction of compounds containing isocyanate groups and hydrolyzable silyl groups in the molecule.
Since the adhesive of the present invention has good high-pressure shower resistance and satisfactory balance of adhesion after baking, it is preferably 0.5 to 10% by weight, based on the total weight of the adhesive, More preferably, it may contain 3 wt% to 5 wt% of a moisture curable resin.

  The adhesive according to the present invention has an elongation rate after curing of 100% or more, and even after being allowed to stand for CKD transport, the shear strength after curing is 150 KPa or more, and the volume change rate is 90% of the initial state. % Or more. By having such elongation, shear strength, and volume retention, the adhesive of the present invention can be suitably used as a mastic adhesive.

  The adhesive of the present invention is preferably a mastic adhesive for assembling and bonding a vehicle body panel, more preferably a fully knockdown type vehicle body panel which is applied to the panel and cured after being transported to an overseas location in an uncured state. It can be used as a mastic adhesive for assembling and bonding.

To carry out assembly bonding of the vehicle body panel, first, the adhesive of the present invention is discharged and applied from the hose tip nozzle of the pressure pump to the bonding portion of the outer panel and inner panel of the vehicle body, and then both panels are applied. Overlap, the peripheral edge of the outer panel can be a hemming structure, and the inner panel can be fixed by spot welding if necessary. The vehicle body panel may be fixed only by spot welding. The pressure pump to be used is for a normal high-viscosity fluid, and a pump having a relatively high air compression ratio of 45: 1 or more is particularly preferable.
In this way, the adhesive of the present invention can be suitably used for assembling and bonding vehicle body panels.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited at all by this.

[Examples 1 to 4 and Comparative Examples 1 to 6]
A mastic adhesive was produced by the following procedure using each component in parts by weight shown in Table 1. First, after synthetic rubber was seated with a mixing roll, the synthetic rubber seated with a strong kneader was mixed and dissolved in a plasticizer. Next, after the remaining components were blended, the mixture was stirred and degassed for 60 minutes under a reduced pressure of 50 mmHg.

(Note 1) Uncrosslinked synthetic rubber, butadiene rubber (Mooney viscosity 43)
(Note 2) Partially crosslinked synthetic rubber, SBR (Mooney viscosity 92, bound styrene content 23.5)
(Note 3) P-quinonedioxime (Note 4) Dimethacrylic zinc (Note 5) N, N'-m-methylphenylene (Note 6) t-Butylperoxybenzoate (Note 7) DINP (Diisononyl phthalate)
(Note 8) Azodicarbonamide (average particle size 8 μm)
(Note 9) LPH-533 manufactured by ADEKA Corporation
(Note 10) Dibutyltin bisacetyl (Note 11) Dicyandiamide (Note 12) Zinc oxide (Note 13) Stearic acid (Note 14) Heavy calcium carbonate (average particle size 8 μm)

[Test method]
1. Elongation rate Measured according to JIS K 6251 “Tensile test”. The adhesive produced as described above was baked at 170 ° C. for 20 minutes, and then punched into a dumbbell shape No. 2 as a test sample. The elongation at break was measured at a pulling speed of 50 mm / min.
○: Elongation rate is 100% or more, ×: Elongation rate is less than 100%

2. Initial shear strength characteristics:
An SPCC-SD steel plate was coated with an adhesive having a thickness of 25 mm × 25 mm × 1 mm, bonded and baked (170 ° C. for 20 minutes), and then subjected to a shear strength test at a pulling speed of 50 mm / min.
○: Shear strength 150 KPa or more, X: Shear strength less than 150 KPa CKD characteristics:
An adhesive having a thickness of 25 mm × 25 mm × 1 mm was applied to the SPCC-SD steel plate and bonded together. Next, after standing for 8 hours at 50 ° C. and 95% RH in an uncured state, the cycle was left for 30 hours at 23 ° C. and 50% RH for 16 cycles. Then, baking (170 degreeC for 20 minutes) was performed, and the shear strength test was done with the pulling speed of 50 mm / min.
○: Shear strength 150 KPa or more, X: Shear strength less than 150 KPa

3. Initial volume change characteristics:
After the adhesive was applied to the aluminum plate in a bead shape with a diameter of 10 mm, the volume change rate of the adhesive before and after baking (170 ° C. for 20 minutes) was measured.
CKD characteristics:
The adhesive was applied in a bead shape at 10 mmφ on an aluminum plate. Next, after standing for 8 hours at 50 ° C. and 95% RH in an uncured state, the cycle was left for 30 hours at 23 ° C. and 50% RH for 16 cycles. Thereafter, baking (170 ° C., 20 minutes) was performed, and the volume change rate of the adhesive before and after baking was measured.
○: Retention rate of 90% or more with respect to the volume change rate in the initial state;

  From the results in Table 2, the adhesives of Examples 1 to 4 have an elongation rate after curing of 100% or more, whereas the adhesives of Comparative Examples 3, 5 and 6 all have an elongation rate after curing. Is less than 100%. In addition, the adhesives of Comparative Examples 1, 2, 4, and 6 do not have sufficient CKD characteristics in shear strength, whereas the curable compositions of Examples 1 to 4 have CKD characteristics in shear strength in any case. It turns out that it is favorable. Furthermore, it can be seen that the adhesives of Comparative Examples 1, 2, and 4 have insufficient CKD characteristics in volume change rate, whereas the adhesives of Examples 1 to 4 can obtain sufficient CKD characteristics in volume change rate. From these facts, it is clear that the curable composition of the present invention has sufficient elongation, adhesive strength and expansion ratio.

Claims (6)

a) a rubber component comprising an uncrosslinked synthetic rubber and / or a partially crosslinked synthetic rubber;
A mastic adhesive comprising b) a quinonedioxime vulcanizing agent and c) a foaming agent and containing 16 to 40 parts by weight of the quinonedioxime vulcanizing agent b) with respect to 100 parts by weight of the rubber component a).   The mastic adhesive according to claim 1, comprising 16 to 35 parts by weight of quinonedioxime vulcanizing agent b) per 100 parts by weight of rubber component a).   The mastic adhesive according to claim 1 or 2, wherein the uncrosslinked synthetic rubber is butadiene rubber.   The mastic adhesive according to any one of claims 1 to 3, wherein the partially crosslinked synthetic rubber is a styrene-butadiene copolymer rubber.   A vehicle body panel characterized in that the mastic adhesive according to any one of claims 1 to 4 is discharged from a hose tip nozzle of a pressure feed pump to an adhesion portion between an outer plate panel and an inner plate panel of a vehicle body, and is assembled and bonded. Bonding method.   The bonding method according to claim 5, which is applied to a complete knockdown-compatible line.