JPH0156663B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adhesion method for obtaining an adhesive between a urethane elastomer and a metal that has good water resistance and heat resistance. Urethane elastomers are used as engineering plastics because they have superior physical properties compared to other synthetic resins and rubbers. Particularly in recent years, attention has been focused on the physical properties of urethane elastomers, and methods have been developed to improve the durability of metals by coating the surfaces of metals with urethane elastomers. Conventionally, phenolic resins or epoxy resins have been known as adhesives for bonding urethane elastomers and metals. These are used to bond high temperature cure cast urethane elastomers to metal, and when casting urethane elastomers.
By leaving it for a long time (several hours to a day) at a temperature of 100 to 150°C, the physical properties of the urethane elastomer are improved and its adhesive properties are also improved. When bonding urethane elastomer and metal, it is energy-efficient to keep the cast urethane elastomer at high temperature for a long time, and casting at high temperature itself is a difficult method. Therefore, casting urethane elastomer in a short time at low temperatures is being considered, but
In the case of casting at a relatively low temperature such as, if the phenolic resin or epoxy resin described above is used to bond the metal and the urethane elastomer, a peel strength of only 1 to 2 kg/cm can be obtained. The present inventors have investigated a method for obtaining an adhesive that has high adhesive strength between metal and elastomer even when urethane elastomer is cast at low temperatures, and has excellent water resistance and heat resistance. It was discovered that by using two types of adhesive compositions, it was possible to obtain sufficiently strong adhesion even when urethane elastomer was cast at low temperatures, and an adhesive with excellent water resistance and heat resistance could be obtained. invention has been achieved. That is, the above object of the present invention is to apply a solution containing a polyepoxy compound and a polyamine compound to a metal surface, and apply an isocyanate group concentration thereon.
According to the first invention, the gist of which is a method for adhering a urethane elastomer to a metal, which comprises applying a solution containing 15 to 50% of an isocyanate compound, and then casting and curing a urethane elastomer stock solution thereon. A solution containing a polyepoxy compound and a polyamine compound (A)
is applied to the metal surface, and after drying, contains an isocyanate compound with an isocyanate group concentration of 15 to 50% and at least one compound selected from the group consisting of polyether, polyester, and polyurethane with a weight average molecular weight of 10,000 or more. This is more preferably achieved by the second invention, which is a method for adhering a urethane elastomer and a metal, which is characterized in that a solution of the urethane elastomer is applied and, after drying, a urethane elastomer stock solution is cast and cured thereon. The present invention will be explained in detail below. Two types of adhesive compositions are used in the present invention; the composition containing a polyepoxy compound and a polyamine compound is called a primary primer, and the composition containing an isocyanate compound is called a secondary primer. The polyepoxy compound used as the main component of the primary primer in the present invention is a terminal epoxy group-containing compound with an average molecular weight of 300 to 4000 obtained by adding epichlorohydrin to bisphenol A, phenol, phenol compounds such as cresol, resorcin, etc., and formaldehyde. Preferred are polyepoxy compounds obtained by reacting epichlorohydrin with polyphenol resins obtained by condensation with aldehydes such as , glyogyzal, and acrolein. Commercially available polyepoxy compounds can also be used. For example, Epicoat-828, 1001, 1004, 1009 or 152, 154 (Epicoat is a trademark) manufactured by Yuka Ciel Epoxy Corporation, or Araldite EPN-1138, 1139 ECN-1235, manufactured by Ciba Geigy.
1273, 1280 (Araldite is a trademark), etc. are used. These may be used alone or in combination. When higher heat resistance is required, polyfunctional polyphenol-based epoxy compounds are preferred. Various known curing agents are used as the polyamine compound used for the purpose of polymerizing the epoxy compound as the curing agent component of the primary primer. For example, compounds containing terminal amino groups synthesized from dimer acid and polyamines such as ethylene diamine, propylene diamine, hexamethylene diamine, diethylene triamine, xylylene diamine, etc. For example, Versamide 115, 125, 140 (trademark, manufactured by Henkel Japan); diethylene triamine, Amines such as tetraethylenepentamine, hexamethylene diamine, propylene diamine, trimethylhexamethylene diamine, isophorone diamine, menthene diamine, xylylene diamine, and these amines and 1,4-butanediol diglycidyl ether, glycerin triglycidyl ether, bis Reaction products with epoxy compounds such as phenol A diglycidyl ether and diaminodicyclohexylmethane; compounds obtained by Mannitz reaction between secondary amines such as dimethylamine and diethylamine and formaldehyde and phenols such as phenol and cresol; There are polyamines obtained by reacting aromatic amines such as aniline and toluidine with aldehydes such as formaldehyde. When more water resistance and heat resistance are required, it is preferable to use aromatic compounds such as xylylene diamine or its epoxy compounds and amide compounds. An epoxy compound obtained by reacting epichlorohydrin with a polyphenol compound as a main ingredient,
It is preferable to use xylylene diamine or its epoxy compound having an amino group at the terminal as a primary primer in combination as a curing agent. Furthermore, the following auxiliary materials can also be added to the primary primer. As auxiliary materials, extender pigments (talc, clay, calcium carbonate, calcium sulfate,
Alumina, silica, calcium silicate, etc.) Coloring pigments (titanium oxide, carbon black, iron oxide, lead oxide, ultramarine blue, phthalocyanine blue, etc.) Rust preventive pigments (lead silicate, calcium leadate, lead chromate, etc.), Flow control agents ( Fine powder silica, asbestos, hydrogenated castor oil, etc.) can be optionally selected and blended. The main agent, curing agent, and auxiliary materials are usually mixed in a solvent to prepare the primary primer. The solvent is a compound that dissolves both the polyamine compound and the polyepoxy compound, such as toluene, xylene, ethylbenzene, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, butyl cellosolve, and acetic acid ester of a cellosolve compound. The mixing ratio of the polyepoxy compound and the polyamine compound is in the range of 0.5/1 to 1/0.5 in terms of equivalent ratio. The amount of the solvent is adjusted appropriately depending on the workability so that the viscosity makes it easy to apply the solvent. Generally, the amount of solvent used is such that the total resin concentration ranges from 2 to 90% by weight. When adding pigment, add it to the total amount of resin.
1 to 500% by weight is preferred. Isocyanate group concentration (weight% of isocyanate groups in the isocyanate compound, hereinafter referred to as NCO%), which is a component of the secondary primer, is 15 to 50%,
Preferably, 15 to 35% of the isocyanate compounds used are aliphatic, cycloaliphatic and aromatic isocyanate monomers having at least two NCO groups in the same molecule, mixtures thereof and modified products thereof. Ru. Specific examples include tolylene diisocyanate (2,4- and/or 2,6-isomer), xylylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate (MDI), a low polycondensate of aniline and formaldehyde, and phosgene. polynuclear polyisocyanates (so-called crude MDI) obtained by reaction with
Examples include carbodiimide-modified diphenylmethane diisocyanate. In addition, terminal NCO obtained by reacting these isocyanate compounds with polyhydroxy compounds
It is also possible to use urethane prepolymers having groups (note that urethane prepolymers are reaction products of isocyanate compounds and polyhydroxy compounds and contain unreacted isocyanate compounds. In this case, the NCO% is is the weight percent of NCO groups contained in the mixture (based on the weight of the mixture).
As the polyhydroxy compound, polyether polyols and polyester polyols, which are usually used in the production of polyurethane, are used. For example, polyalkylene ether polyols with an average molecular weight of 300 to 10,000 are obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide to polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, pentaerythritol, sorbitol, and sucrose. , polyether polyols such as polytetramethylene ether glycol with an average molecular weight of 600 to 10,000 obtained by ring-opening polymerization of tetrahydrofuran, ethylene glycol, propylene glycol, 1,4-butanediol, hexylene glycol, diethylene glycol, dipropylene glycol, etc. A polyester polyol with an average molecular weight of 300 to 6000 obtained by the condensation reaction of a difunctional alcohol with a difunctional carboxylic acid such as adipic acid, succinic acid, azelaic acid, and phthalic acid, and caprolactone are ring-opening polymerized. Compounds having a terminal hydroxyl group with an average molecular weight of 300 to 6,000 are exemplified. If the NCO% is less than 15%, a strong adhesive cannot be obtained, and if the NCO% is too high, the adhesive surface becomes brittle. Usually, isocyanate compounds with NCO% of 15-50% are practical, but NCO% is 20-35%.
Even better adhesives can be obtained by using isocyanate compounds. Further, in order to obtain rapid strength development, aromatic polyisocyanates such as MDI, crude-MDI, carbodiimide-modified MDI, or urethane prepolymers obtained from these isocyanates are preferred. In the present invention, in order to achieve good adhesion, which is the objective of the present invention, it is sufficient to use the primary primer and secondary primer of the above composition, and it is not necessary to add a silane coupling agent to the primary primer. This is what I discovered. However, in order to speed up the build-up of adhesive strength and improve water resistance during urethane elastomer stock solution casting curing, it is necessary to
It is preferable to add a polymer compound such as polyether, polyester or polyurethane having a molecular weight of 10,000 or more. The weight average molecular weight is measured using a liquid chromatograph by preparing a calibration curve using standard polystyrene. The detector uses an optical differential refractometer. Therefore, the average molecular weight referred to here is strictly a comparison of the molecular size (dimensions) with respect to polystyrene molecules. The weight of each molecular weight is calculated on the assumption that the refractive index of each molecular weight is the same. Calculation is performed using the following formula. w=ΣMiWi/ΣWi w: Weight average molecular weight Mi: Molecular weight Wi: Weight of molecular weight Mi (here, the height of the peak shown in the chart is used) As the polyether and polyester, the polyester used in the production of the urethane prepolymer was used. A compound of the same type as the ether polyol and polyester polyol (however, the molecular weight is different) and has a weight average molecular weight of 10,000 or more is used. Examples of polyester include PLACCEL H-1,
Commercial products such as PLACCEL H-4 and PLACCEL H-7 (manufactured by Daicel Chemical Industries, Ltd., PLACCEL is a trademark) can also be used. The polyurethane is a reaction product of the isocyanate compound used in the production of the urethane prepolymer and a polyether polyol or a polyester polyol, and has a weight average molecular weight of
More than 10,000 are used. The polyurethane may have either a terminal isocyanate group or a terminal hydroxy group, but from the viewpoint of storage stability, polyurethane having a terminal hydroxy group is preferable. These polymer compounds are used in an amount of 0.05 to 3 times by weight, preferably 0.1 parts by weight, per 1 part by weight of the isocyanate compound.
It is used at a ratio of ~2 times the weight. Secondary primers include MDI, crude MDI,
Carbodiimide-modified MDI alone or a mixture thereof or a urethane prepolymer thereof is used, and the polymer compound is preferably a polyester, a polyether, or a reaction product of a polyester polyol and an isocyanate. Like the primary primer, the secondary primer is also used with a solvent. As the secondary primer solvent, a solvent that dissolves the isocyanate compound and the polymer compound and is inert to the isocyanate group is used. Examples include toluene, xylene, methyl ethyl ketone, methylene chloride, cellosolve acetate, methyl isobutyl ketone, trichlene, ethyl acetate, butyl acetate, and the like. The amount used is 0.4 to 30 times the total amount of isocyanate compound and polymer compound,
Preferably it is 0.5 to 10 times the weight. When using urethane prepolymers and polyurethanes as components of the secondary primer, solvents that strongly swell them, such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-
It is preferable to use a highly polar compound such as methylpyrrolidone in combination. Use of these solvents improves the adhesion between the primary primer and the urethane elastomer. The amount used is 1 to 100% by weight, preferably 3 to 70% by weight based on the total resin content.
It is. By using the primary primer and secondary primer having the above compositions, it is possible to firmly bond the urethane elastomer and the metal at low temperatures, and it is possible to obtain an adhesive with excellent water resistance and heat resistance. Further, in order to obtain an adhesive with high adhesiveness and water resistance, it is preferable that the secondary primer contains a polymer compound and that the primary primer contains a silane coupling agent. Silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, or γ-glycidoxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane. Silane or a reaction product with γ-captopropyltrimethoxysilane is preferred. When adding a silane coupling agent, it is preferably 0.01 to 20% by weight based on the total amount of the polyepoxy compound and polyamine compound (hereinafter simply referred to as the total resin amount). The urethane elastomer used in the present invention is usually prepared by combining an isocyanate group-containing prepolymer solution (first solution) obtained by reacting a polyoxyalkylene polyol or a polyester polyol with a polyisocyanate compound, a polyoxyalkylene polyol, or a polyester polyol, and a chain. It is manufactured by mixing and casting a solution (second liquid) containing an extender, a catalyst, etc. (these liquids are referred to as the urethane elastomer stock solution). The polyoxyalkylene polyols in the first and second liquids are ethylene glycol, propylene glycol, 1,4-butanediol,
Compounds obtained by adding ethylene oxide, propylene oxide, butylene oxide, etc. to glycerin, trimethylolpropane, etc., or compounds obtained by ring-opening polymerization of tetrahydrofuran are preferred, and those with an average molecular weight of 700 to 10,000 are preferably used. It will be done. Polyester polyols are difunctional alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, hexylene glycol, diethylene glycol, and dipropylene glycol, and adipic acid, succinic acid, azelaic acid,
Average molecular weight 700~ obtained by condensation reaction with difunctional carboxylic acid such as dicarboxylic acid such as phthalic acid
Average molecular weight 700 ~ obtained by ring-opening polymerization of a compound with a terminal hydroxyl group of 6000 and caprolactone
Compounds with a terminal hydroxyl group of 6000 are preferably used. These glycols and acids may be used alone or in combination. The polyoxyalkylene polyol or polyester polyol may be used alone or in combination of two or more. As the polyisocyanate compound serving as a raw material for the prepolymer of the first liquid, diisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, and compounds obtained by partially carbodiimidizing diphenylmethane diisocyanate are preferred. The isocyanate group concentration of the prepolymer is 2 to 25
%, reaction rate, and properties of the cast product, a more preferable concentration is 2 to 15%. As the chain extender, short chain diols such as ethylene glycol, 1,4-butanediol, dipropylene glycol, and hexylene glycol, and aromatic diamines such as methylene bis(o-chloroaniline) and methylene dianiline can be used. The catalyst is a tertiary amine catalyst that is generally used to promote the urethane reaction, such as diazabicyclooctane, or an organometallic compound that is generally used to promote the urethane reaction, such as tin octoate, dibutyltin dioctoate, dibutyltin dilaurate, or lead octoate. be. The method of the present invention can be particularly suitably used for bonding elastomers and metals that can be cured at temperatures below 80°C. Examples of metals to which the urethane elastomer is bonded include iron, stainless steel, aluminum, and magnesium. The method for adhering metal and elastomer is carried out as follows. First, each component of the primary primer is mixed with a solvent, and the resulting mixture is dried to a thickness of 5 to 200 μm.
Preferably, it is applied to the metal in an amount of 10 to 150μ (preferably about 10 to 50μ in the first invention) and left for 2 hours or more at 20°C, or 30 minutes or more when heated to about 60°C. do. Heating the coated material at a high temperature improves the water resistance of the adhesive. Once the surface of the coated material is tack-free, add a mixture of each component of the secondary primer to a solvent to a dry thickness.
Apply in an amount of 200μ or less, preferably 10 to 150μ, and leave until the solvent scatters, usually within 3 hours. Next, a urethane elastomer stock solution, which is a mixture of the first and second liquids, is poured and cured. If it is left as it is at room temperature for about a week, the strength of the elastomer will stabilize and sufficient adhesive strength will be obtained. Furthermore, if necessary, the urethane elastomer stock solution may be heated to 100°C or higher after casting. As detailed above, according to the present invention, when a urethane elastomer stock solution that can be cured at a relatively low temperature is used, it is possible to obtain a product with good adhesion even at low temperatures without taking the trouble of heating. Moreover, the resulting adhesive has very good water resistance. The present invention will be explained below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In addition, the weight average molecular weight of the polymer compound in the following examples was measured as follows. Measurement of weight average molecular weight A high performance liquid chromatograph HLC-802A (manufactured by Toyo Soda Kogyo Co., Ltd.) was equipped with two gel permeation separation columns G-2000H-8 and G-3000H- which mainly consist of styrene-divinylbenzene copolymer. 8
1, G-4000H-8 1 (G2000H-8 can separate molecules up to 10,000, G-4000H-8 can separate up to 10,000 molecular weight,
3000H-8 can separate up to 60,000, G-4000H-8
can separate up to 400,000 (both manufactured by Toyo Soda Kogyo Co., Ltd.) A differential refractometer is selected as the detector, and tetrahydrofuran is used as the solvent. The temperature of the column is stabilized at 40° C. for about 4 hours while the solvent is flowing at a rate of 1.1 ml/min. On the other hand, weight average molecular weight (w)
and number average molecular weight (n) (w/n)
A 3% tetrahydrofuran solution is prepared by mixing several types of standard polystyrene purified to 1.01 to 1.05 with different molecular weights. This solution is injected into a liquid chromatograph to obtain a molecular weight distribution curve. Write the relationship between retention time and molecular weight on semi-log graph paper to create a standard curve. In addition, the synthesized polymer substances are also 3%
Prepare a tetrahydrofuran solution of and obtain a molecular weight distribution curve in the same way. The weight average molecular weight is calculated from the curve obtained here according to the formula shown above. Production of primary primer A Production of main ingredient A polyepoxy compound, a silane coupling agent, and a solvent are mixed and heated to 60°C while stirring.
A homogeneous solution was obtained. For 600g of this solution,
A pigment was added and kneaded using a paint mill to produce a main ingredient for a primary primer. Table 1 shows the types and usage amounts (grams) of the epoxy compound, solvent, silane coupling agent, and pigment.

[Table] B Production of curing agent Experiment No. 1 270 g of xylylene diamine and 60 g of Epicote 828 were mixed in a flask with stirring for 90 min.
The reaction was carried out at ℃ for 5 hours. 170 g of xylene, 90 g of butyl cellosolve and 170 g of methyl ethyl ketone were added to the reaction product to obtain a homogeneous solution. This solution is referred to as a curing agent (A-1). Experiment No. 2 100g of Tomide 215 (dimer acid polyamide, manufactured by Fuji Kasei Kogyo Co., Ltd., trade name), xylene 60g, butyl cellosolve 20
g and 40 g of methyl ethyl ketone were added and stirred at room temperature to obtain a homogeneous solution. This solution is used as a curing agent (A-2). Experiment No. 3 550 g of 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5,5]-undecane and 100 g of 1,4-butanediol diglycidyl ether were reacted at 80° C. for 5 hours with stirring. Reaction products include xylene 200g, butyl cellosolve 50g, methyl ethyl ketone 400
g and 100 g of methyl isobutyl ketone were added to obtain a homogeneous solution. This solution is used as a curing agent (A-3). Production of secondary primer A Production of urethane prepolymer Experiment No. 1 A polyisocyanate compound and a polyhydroxy compound were reacted at 80°C for 3 hours to produce a urethane prepolymer. Types and usage amounts (grams) of polyisocyanate compounds and polyhydroxy compounds,
Table 2 also shows the isocyanate group concentration (expressed as NCO%) of the urethane prepolymer.
Shown below.

[Table] B Production of polymeric compounds Mix 4,4'-diphenylmethane diisocyanate (MDI) or 80/20-TDI and various polyhydroxy compounds in dehydrated toluene,
Polyurethane was produced by reacting at ℃ for 30 hours. Table 3 shows the types and amounts used (in grams) of the reaction raw materials and the weight average molecular weights of the reaction products (measured by gel permeation chromatography).

[Table] C Production of secondary primer The urethane prepolymer or various polyisocyanate compounds (denoted as NCO component) produced in A are mixed with various polymer compounds (denoted as polymer component) and solvent to make secondary primer. A primer was produced. Table 4 shows the types and amounts (grams) of the raw materials.

【table】

[Table] Production of urethane elastomer stock solution Experiment No. 1 Mix 10 kg of polytetramethylene ether glycol (hereinafter referred to as PTMG) with an average molecular weight of 10,000 and 5 kg of 80/20-TDI,
The reaction was carried out at 70°C for 4 hours to obtain a urethane prepolymer liquid having terminal isocyanate groups with an isocyanate group concentration (hereinafter referred to as NCO concentration) of 10.5%. 30% of the obtained reaction solution
The mixture was cooled to ℃ and stirred under reduced pressure of 20 mmHg to remove dissolved air. Pour this liquid into T
-It is called liquid. On the other hand, 7.5 kg of PTMG with an average molecular weight of 1000 and 2.5 kg of methylene bis(o-chloroaniline)
Kg and 30 g of diazabicyclooctane were mixed and heated to 100°C to obtain a homogeneous liquid. This liquid was cooled to 30°C and stirred under reduced pressure of 20 mmHg to remove dissolved air.
This liquid is called R-liquid. Experiment No. 2 Same PTMG10 as used in Experiment No. 1
Kg and diphenylmethane diisocyanate 10
Kg and reacted in the same manner as in Experiment No. 1 to obtain a urethane prepolymer solution having terminal isocyanate groups with an NCO concentration of 12.5%. The reaction solution was treated in the same manner as in Experiment No. 1.
This liquid is called M-liquid. On the other hand, the same as that used in Experiment No. 1
PTMG850g and diethylene glycol 150g
g and 3 g of diazabicyclooctane were mixed and heated to 70°C to obtain a homogeneous solution. This liquid was treated in the same manner as in Experiment No. 1. The obtained liquid is called G-liquid. Example 1 The oil on an iron plate whose surface was roughened with sandplast was removed by washing with methylene chloride, and the surface was coated with E- produced by A as a primary primer.
A homogeneous solution obtained by sufficiently mixing 100 g of A-1 and 53 g of A-2 prepared in B was applied with a brush and dried in an oven at 80°C for 30 minutes. The thickness of the coating film after drying was 100μ. Next, the secondary primer U-1 prepared in step C was applied thereon and left for about 10 minutes. The thickness of the coating film formed by the secondary primer after drying was 30μ. On the other hand, 200 g of T-liquid and 140 g of R-liquid manufactured in
Mix vigorously but without introducing air, quickly remove air bubbles generated during mixing under a reduced pressure of 1 mmHg, and apply the resulting mixture in a thick layer onto the previously applied secondary primer U-1. Pour to a thickness of 5 mm, under an atmosphere of 25℃ and 50%RH (relative humidity).
It was left for 14 days. The thus obtained adhesive between the urethane elastomer and the iron plate has a width of 25 mm and a length of 150 mm.
A 180° peel strength test was carried out at a tensile speed of 50 mm/min according to the test method of JIS-K-6301 (hereinafter referred to as normal peel test).
The elastomer broke when the adhesive strength of the test piece exceeded 16 kg/cm. Meanwhile, a test piece of similar size was placed in warm water at 50℃ for 30 minutes.
After being immersed for 1 day, the elastomer was left to stand for 2 days in an atmosphere of 25° C. and 50% RH, and then the above-mentioned peel test (hereinafter referred to as post-immersion peel test) was conducted, and the elastomer was destroyed at 12 kg/cm or more. Examples 2 to 32 A urethane elastomer metal plate was bonded to the metal plate in the same manner as in Example 1 using the metal plate, primary primer, secondary primer, and urethane elastomer shown in Table 5. The adhesive strength of the adhesive was measured in the same manner as in Example 1. The results are shown in Table-5. The amounts of each compounded component are as follows. Primary primer base agent 100g Hardening agent Examples 2, 4-27, 29, 32 20g Examples 3, 28, 30, 31 40g Urethane elastomer 1st liquid 200g 2nd liquid Examples 2-30 140g Examples 31, 32 125g For reference, the results of Example 1 are also shown in Table-5.

【table】

[Table] Example 33 An iron plate whose surface has been roughened by sandblasting is washed with methylene chloride, and 50 g of E-4 produced in A as a primary primer and 10 g of A-1 produced in B are mixed on this surface. The liquid was applied with a brush and dried in an oven at 80°C for 1 hour (thickness: 50μ). Next, 100 urethane prepolymer (P-1) produced in step A, 90 g of toluene, and 20 DMF
Apply the mixture of g. After leaving it at room temperature for 30 minutes, mix vigorously 200g of T-liquid and 140g of R-liquid prepared above, quickly remove the bubbles generated under a reduced pressure of 1mmHg, and apply the mixture to the previously coated board to a thickness of 5mm. It was poured and left in an atmosphere of 25°C and 60% RH for 7 days. This material was heated at 100°C for 1 hour. It took about 20 days for the material that was not heated to develop strength. obtained,
Width 25 from adhesive between urethane elastomer and iron plate
Cut out a test piece with a length of 150 mm and pass JIS K-6301.
The 180° peel strength was measured at a tensile speed of 50 mm/min according to the test method of . The peel strength of the adhesive piece is 16Kg/
It was over cm. On the other hand, this test piece was immersed in warm water at 50°C for 14 days, then left in an atmosphere of 25°C and 50% RH for 2 days, and then subjected to the above-mentioned peel test, and the peel value was 12 kg/cm or more.

Claims (1)

[Claims] 1. A solution (A) containing a polyepoxy compound and a polyamine compound is applied to a metal surface, and after drying, a solution (B) containing an isocyanate compound with an isocyanate group concentration of 15 to 50% is applied thereon. A method for adhering urethane elastomer and metal, which is characterized by coating, drying, and then casting and curing a urethane elastomer stock solution thereon. 2. A solution (A) containing a polyepoxy compound and a polyamine compound is applied to the metal surface, and after drying, an isocyanate compound with an isocyanate group concentration of 15 to 50% and a polyether, polyester, and A method for adhering a urethane elastomer to a metal, the method comprising applying a solution containing at least one compound selected from the group consisting of polyurethane, drying the solution, and then casting and curing a urethane elastomer stock solution thereon. 3. The method according to claim 2, wherein the solution (A) contains a silane coupling agent.