JPS624477A - Method for adhering urethane elastomer and metal - Google Patents

Abstract

PURPOSE:To securely adhere a metal and urethane elastomer and to obtain the adhered material having excellent resistance to water and heat by coating two kinds of specific primers on the surface of the metal, pouring the stock soln. of the urethane elastomer thereon and curing the same thereby developing the initial adhesive power in an early period. CONSTITUTION:The primary primer compsn. contg. a polyetpoxy compd. (e.g., phenol novolak type epoxy compd. obtd. by adding epichlorohydrin to bisphenol A) and polyamide compd. as a curing agent component is coated on the surface of the metal. The secondary primer compsn. contg. an isocyanate compd. having 5-50wt% isocyanate group or yrethane prepolymer having the isocyanate group at the terminal and polyepoxy compd. is coated thereon and further the stock soln. of the urethane elastomer is poured thereon and is cured. As a result, the adhered material which develops the adhesive powder in a short heating period and has the excellent resistance to water and heat is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an adhesive method for obtaining a crushed product of a urethane elastomer and a metal having excellent water resistance and heat resistance.

Urethane elastomers have excellent mechanical properties, abrasion resistance, and chemical resistance, so they are used in various industrial materials such as belts and solid tires.

[Conventional technology]

-7. Depending on the application of urethane elastomer, adhesion to metal is often required. For example, when adhering 7XI thermosetting urethane elastomer, represented by adiprene, to metal, it is usually OhemlOk 2 / g or a.
Phenol resin primers such as onap //1740 (all trade names) and other epoxy resin primers are conveniently used.

However, when using these primers, in order to cure the elastomer and to obtain sufficient adhesive strength, it is necessary to heat the urethane elastomer at a temperature of 100°C for several hours or overnight in order to obtain sufficient adhesive strength. .

Such a method requires heating at a high temperature for a long period of time, which is energy uneconomical and also unfavorable in terms of work.

In this case, even if the initial adhesive strength is sufficient, if the adhesive is immersed in hot water for a long period of time, or if it is used in a hot water immersion environment where there is a temperature gradient, the adhesive strength will decrease significantly, resulting in satisfactory water resistance. I can't get sex.

Using a urethane elastomer that cures at room temperature or a relatively low heating temperature is economical in terms of thermal energy during curing, but when adhering to metal, a primer that can be bonded at low temperatures is required.

However, when using the above-mentioned pheno-)V resin-based or epoxy resin-based primers, good adhesion cannot be obtained at heating temperatures lower than 700°C, and water resistance and heat resistance are not satisfied, so they cannot be applied. Ta.

The inventors of the present invention have diligently studied a primer for firmly adhering urethane elastomer, which hardens at a relatively low temperature, to metal without impairing its water resistance and heat resistance, and published JP-A-Sho! r7-/
g41'17! We have developed an adhesion method using a two-coat primer as shown in No. 1 and Japanese Patent Publication No. Sho SG-Y OIB3.

The method was to first apply an epoxy primer to the metal surface, then apply a urethane primer, then inject a urethane elastomer stock solution onto it and bond it at room temperature.

But f! Although the above method has the advantage of being able to bond at room temperature, it has the disadvantage that the initial adhesive strength is slow to develop. However, it was difficult to obtain sufficient adhesion, as foaming and lifting occurred at the interface between the urethane primer and the urethane primer.

[Purpose of the invention]

Therefore, the present inventor has discovered that when a urethane elastomer that hardens at room temperature or by heating is brought into contact with a metal mold, the initial adhesive strength is developed quickly, the adhesive is strong, and the adhesive is water resistant.
As a result of further studies in order to obtain an adhesive with excellent heat resistance, we decided to use two specific types of primers and create a bond between the urethane elastomer and the metal by heating for a relatively short time when the urethane elastomer is in contact with the urethane elastomer. The present inventors have discovered that it is possible to obtain a bonded material that exhibits strong adhesive strength and is excellent in heat resistance and water resistance, particularly in terms of water resistance under temperature gradients, and has thus arrived at the present invention.

That is, the present invention provides a primer composition compound containing a polyepoxy compound and a polyamine compound, or a urethane prepolymer having an isocybnate group at the terminal;
The present invention relates to a method for adhering a urethane elastomer to a metal, which comprises applying a primer composition containing a noeboxy compound, injecting a urethane elastomer raw material onto the primer composition, and curing and bonding the primer composition.

[Structure of the invention]

The present invention will be explained in detail below.

Two types of adhesive compositions are used in the present invention;
A composition containing a polyepoxy compound and a polyamine compound is called a primary primer, and a composition containing an isocyanate compound and a polyepoxy compound is called a secondary primer.

The primary primer used in the present invention is a 12-component type, and the polyepoxy compound used as its main and subcomponent is obtained by adding epichlorohydrin to bisphenol A and has an average molecular weight of 200 to 10,000.
Polyhydric epoxy obtained by reacting epichlorohydrin with a polyphenol stool obtained by condensing a phenol compound such as phenol, cresol, or resorcin with an aldehyde such as formaldehyde, glyol, or acrolein. Compounds etc. are preferred.

Commercially available polyepoxy compounds can also be used.

For example, Epicoat-gcog manufactured by Yuka Shell Epoxy Co., Ltd.
/θO/, 1001I, 100 de or /3 co, 73 da (Epicote is a trademark), or Ciba Geigy Araldite BPN-113g, //39 KON-
/13k.

/, :17J, /210 (Araldite is a trademark), etc. These can be used alone or in combination. When higher heat resistance is required, polyfunctional polyphenol-based epoxy compounds are preferred.

- As the polyamine compound used for the purpose of polymerizing the epoxy compound as the curing agent component of the next primer, various known curing agents can be used.

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., such as Perzamide/15
, Noko 5%/DaO (trademark, Nippon Henkel Co., Ltd.); amines such as diethylenetriamine, tetraethylenepentamine, hexamethylenediamine, propylenediamine, trimethylhexamethylenediamine, isophoronediamine, menzendiamine, xylylenediamine; These amines and he+-butanediol diglycidyl ether,
Glycerin triglycidyl ether, bisphenol A
・Reactants with epoxy compounds such as diglycidyl ether and diaminodicyclohexylmethane, dimethylamine,
Compounds obtained by the Mannich reaction of secondary amines such as diethylamine, formaldehyde, and phenols such as phenol and Fresol, or polyamines obtained by the reaction of aromatic amines such as aniline and toluidine with aldehydes such as formaldehyde. There is. 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.

A bisphenol A type epoxy compound obtained by adding epichlorohydrin to bisphenol A as a main ingredient, or a phenol novolak type epoxy compound obtained by reacting epichlorohydrin with a polyphenol compound,
The curing agent is xylylenediamine or a modified product thereof, and the terminal thereof is an amino group. Preferably, the compounds are combined into a primary brimer.

Furthermore, the following auxiliary materials can also be added to the primary primer. Subsidiary materials include extender pigments (talc, clay, calcium carbonate, calcium sulfate, alumina, silica, lucium 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 laminate, etc.), flow regulators [
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 0.0 in terms of equivalent ratio. The range is from // to //θ, 5.

The amount of the solvent is appropriately adjusted 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 901 tons. When adding a pigment, it is preferable to add a no-ro-o-m amount to the total amount of resin.

The concentration of isocyanate groups in the isocyanate compound or urethane prepolymer that is a component of the secondary primer (the weight predominance of inocyanate groups in the isocyanate compound as a solid content excluding the solvent, hereinafter referred to as N (30%) is 3
-50%, preferably 10-33% is used.

As the isocyanate compound, aliphatic, alicyclic and aromatic isocyanate monomers having at least a small number of Neo groups in the same molecule, mixtures thereof, and modified products thereof are used. Specific examples include: Tolylene diisocyanate (co, lI- and/or co, 6-isomer), xylylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate (MD eno, obtained by reaction of a low polycondensate of aniline and formaldehyde with phosgene) Examples include polynuclear polyinocyanates (so-called crude MDnJ, carbodiimide-modified diphenylmethane diisocyanate, etc.).

In addition, NC having a terminal Neo group obtained by reacting these isocyanate compounds with a polyhydroxy compound
O group concentration 5~! It is also possible to use a urethane prepolymer with a weight percent of % by weight of Neo 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, the average molecule n300~/0.000 obtained by adding alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to polyhydric alcohol such as ethylene glycol, propylene glycol, glycerin, pentaerythritol, sorbitol, and sucrose. Polyalgylene ether polyol, average molecular weight obtained by ring-opening polymerization of tetrahydrofuran AOO~/0.0
Polyether polyols such as 00 polytetramethylene ether glycol, difunctional alcohols such as ethylene glycol, propylene glycol, p-butanediol, hexylene glycol, diethylene glycol, and dipropylene glycol, and adipic acid, succinic acid, and azelaic acid. , average molecular weight obtained by condensation reaction with difunctional carboxylic acid such as Futar/I/acid,
Average molecular weight 300-100.000 obtained by ring-opening polymerization of 0 polyester polyol and caprolactone
An even better adhesive can be obtained by using a compound having a terminal hydroxy group, or a urethane prepolymer. In addition, in order to obtain fast adhesive strength, aromatic polyisocyanates such as MDI, Crude-MDI,
Carbodiimide-modified MDI or urethane prepolymers obtained from these isocyanates are preferred.In addition, in the present invention, a polyepoxy compound is essential as a component of the secondary primer, but specific examples of these include polyepoxy compounds in the primary primer. The same compounds as those used can be mentioned, and a compound having an average molecular weight of 200 to 100θ0 is selected.

These polyepoxy compounds are used in an amount of 7 to 300 parts per 100 parts of isocyanate compound or urethane prepolymer.
Preferably by weight! 1Z is used at a rate of ~10ON.

As the secondary primer, it is preferable to use the above-mentioned MDI, crude MDI, carbodiimide-modified MDI alone or in combination, or their urethane prepolymers, and as the polyepoxy compound, it is preferable to use a bisphenol A type epoxy compound or a phenol novolak type epoxy compound. Furthermore, in the present invention, it is preferable that the secondary brimer be used as a co-liquid type like the 7th brimer, and it contains an isocyanate compound, a component containing a urethane prepolymer having an isocyanate group at the end, and a component containing a polyepoxy compound. It consists of λ liquid.

Like the primary primer, the secondary primer is also used with a solvent.

Isocyanate compounds are used as secondary primer solvents,
A solvent is used that dissolves the urethane prepolymer and the polyepoxy compound, respectively, and is inert to isocyanate groups and epoxy groups. Examples include toluene, xylene, methyl ethyl ketone, methylene chloride, cellosolve acetate, methyl isobutyl ketone, trichlene, ethyl acetate, butyl acetate, and the like. Amount used: A solvent having a strong swelling effect, such as a strongly polar compound such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, or N-methylpyrrolidone, may also be used in combination.

By using the primary primer and secondary primer of the above composition, the urethane elastomer and the metal can be firmly bonded by heating for a relatively short time, and
Water resistance (particularly water resistance due to temperature gradients), and #f#
Adhesive with excellent properties? Obtainable.

Further, in order to obtain an adhesive with high adhesiveness and water resistance, it is preferable that the primary primer contains a silane coupling agent.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaftpropyltrimethoxysilane, or r-glycidoxypropyltrimethoxysilane and γ- Aminopropyltriethoxysilane or γ-
A reaction product with meyacaptopropyltrimethoxysilane is preferred.

When a silane coupling agent is added, the total amount of polyepoxy compound and polyamine compound is referred to as the total resin amount. It is preferably 0.07 to 20% by weight based on the amount of carbon.

The urethane elastomer used in the present invention is usually prepared by combining polyol with an isocyanate group-containing prepolymer liquid (first liquid) obtained by reacting a dialkylene polyol or a polyester polyol with a polyisocyanate compound, and polyoxia/L/-? A mixed liquid (second liquid) containing lemboliol or polyester polyol, a chain extender, a catalyst, etc. (These liquids are referred to as the urethane elastomer stock solution.)fj! :l'l! It is arranged by matching and casting.

The polyoxyalkylene polyols in the first and second liquids are obtained by adding ethylene oxide, propylene oxide, butylene oxide, etc. to ethylene glycol, propylene glycol, Hiro-butanediol, glycerin, trimethylolpropane, etc. or compounds obtained by ring-opening polymerization of tetrahydrofuran, and have an average molecular weight of 700 to 1000.
0 is preferably used.

Polyester polyol is a combination of difunctional alcohols such as ethylene glycol, propylene glycol, l,lI-butanediol, hexylene glycol, diethylene glycol, and dipropylene glycol, and dicarboxylic acids such as adipic acid, succinic acid, azelaic acid, and phthalic acid. An average molecule obtained by open-liming a compound with a terminal hydrochloride group with an average molecular weight of 700 S-&000 obtained by a condensation reaction with a difunctional carboxylic acid and caprolactone! A compound having a terminal human mixi group of 700 to &000 is preferably used. These glycols and acids can be used alone or in combination. The polyester polyols used as polyoxyalkylene polyols 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, diinocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, and compounds obtained by partially carposiimidizing diphenylmethane diisocyanate are preferred.

The isocyanate group concentration of the prepolymer is ko~ko! %, reaction rate, and the quality of the cast material, the more preferable concentration is ~/
j%.

As chain extenders, aromatic diamines such as short-chain dionopemethylene pinu (0-chloroaniline), methylene dianiline, etc., such as ethylene glycol, Hiro-butanediol, dipropylene glycol, and hexylene glycol, are used. I can do it.

The catalyst is a tertiary amine catalyst used to promote general urethanization reactions such as diazabicyclooctane, or tin octoate.
dibutyltin dioctoate, dibutyltin dilaurate,
It is an organometallic compound commonly used to promote urethane reactions, such as lead octoate.

The method of the present invention is particularly suitable for bonding urethane elastomers and metals that are cured at room temperature to 7rC1#. 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 next primer is mixed in a solvent, and the resulting mixed solution is dried to a thickness of 3 to 00μ, preferably i.
It is applied to the metal in an amount of 0 to 100μ, and left to stand for at least one hour at -0°C, or for at least 30 minutes when heated to about 60°C. Furthermore, heating the coated material at a high temperature improves the water resistance of the adhesive. Once the surface of the coated object has become tack-free, apply a mixture of each component of the secondary primer in a solvent in an amount such that the dry thickness will be 200μ or less, preferably 10 to 10μ, and the solvent will scatter. at room temperature until
Leave it for a few hours but remove the solvent? For sufficient drying, it is preferable to dry with warm air. Next, the urethane elastomer raw material g containing the first liquid and the second liquid is poured and cured. Then AO-/20℃, preferably 70-100℃
When the elastomer is heated for about 7 hours and then left at room temperature for about a week, the physical properties of the elastomer become stable and sufficient adhesive strength is obtained.

〔Example〕

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.

Production Example 1 - Production of primary primer> In a three-rose bulb flask, Epicoat 100/C manufactured by Yuka Shell Co., Ltd., bisphenol Afjl:r-Ho#'
i Resin, epoxy equivalent weight SQ~500, trade name) 3o
og, xylene/! Og'ff: The mixture was prepared and stirred under reflux at 60°C to uniformly dissolve it.

11 / Riko ~ /79) /170 g
, KBM-da 03 (manufactured by Shin-Etsu Chemical Co., Ltd., silane coupling agent) 1OI was added and stirred to obtain a homogeneous solution.

Next, add rutile titanium oxide, ytI, as a pigment to this solution.
I
After premixing, the mixture was kneaded using three rolls to produce a main ingredient for primary glimer.

Metaxylylene diamine (manufactured by Mitsubishi Gas Chemical Co., Ltd.)
and Epicote T, 1TC Yuka Shell Co., Ltd., bisphenol A type epoxy resin, epoxy equivalent lzada ~ iqlI)
While stirring the bog in a flask under dry nitrogen,
The reaction was carried out at 90° C. for 3 hours, and after being allowed to cool, the reaction product was mixed with Xylenco tag, ethyl cellosolve 909, and methyl ethyl ketone/709 to obtain a homogeneous solution.

This solution was used as a curing agent for the primary primer.

Production Example λ Production of Primary Brimer> In a three-piece separable flask, add Epicoat Zako r (manufactured by Yuka Shell Co., Ltd., bisphenol A type epoxy fat, epoxy f7kigtt~l Tadanokoichi ρS, Epicoat/
S- (manufactured by Yuka Shell Co., Ltd., phenol novolac type epoxy resin, epoxy per i/7) 71/kudeno, xylene/109, KBM-QO'JC Shin-Etsu Chemical, silane coupling agent) ioy was added and stirred to homogenize. A solution was obtained.

In this solution, rutile type titanium oxide 3 da Og was added as a pigment.
After adding talc hog and Aerosil Φco00 (manufactured by Nippon Aerosil Co., Ltd., fine powder silica) iog and premixing,
The mixture was kneaded using this roll to produce a main ingredient for the next primer.

Note that the curing agent obtained in production M+/ was commonly used.

Manufacturing example-3~? Production of secondary brimer> Urethane prepolymer was produced by reacting a polyisocyanate compound and a polyhydroxy compound in a solvent or without a solvent in a triple flask under dry nitrogen at 0°C for several hours. . A component containing a polyisocyanate compound or a urethane prepolymer was used as a liquid A. Type and amount of raw materials used for liquid A (Cg) and isocyanate group content (g) in terms of solid content
(denoted as N00%) is shown in Table-7.

In addition, the component -i was prepared by uniformly dissolving a polyepoxy compound in a solvent. Types of raw materials used for B liquid and ft C9
) are also shown in Table-7.

Production Example-7O <Production of urethane elastomer stock solution> Polytetramethylene ether glycol (hereinafter referred to as PTMGloooo) with an average molecular weight of 000 tok! 9
Toza 0-TD [2,41 bodies go%, 6 bodies mixed with 20% tolylene diisocyanate Skg, heated at 70℃
The isocyanate group concentration is C or less, No.
A urethane prepolymer liquid having 70.3% terminal isocyanate groups (referred to as Oa degree) was obtained. The resulting reaction solution was cooled to 30° C. and stirred under reduced pressure of Otnrx Hg to remove dissolved air. This stock solution is called T solution.

10,000, PTMGlooo 7. j IK9 and methylenebis(0-chloroaniline)2. ! Rkg and diazabicyclooctane 309 were mixed and heated to 100°C to obtain a homogeneous liquid. Cool this stock solution to 30℃, -〇 a
The mixture was stirred under a reduced pressure of m Hg to remove dissolved air. This liquid is called R liquid.

Production example-//<Production of urethane elastomer stock solution> PTMG 10oo lo# and diphenylmethane diisocyanate (manufactured by Upjohn Co., Ltd., product name: 5Onat)
f3/ko! rM) IOIKg and reacted in the same manner as in Production Example/1 to obtain a urethane prepolymer liquid having terminal isocyanate groups with a NOO@degree of 12.5%. This raw material (g) was treated in the same manner as in Production Example 1. This stock solution 'Yl
〇-10,000 called ffi, PTMOloooo g70j;
1 and 4t-butanedio-)v/30 g and 0.1 g of dibutyltin dilaurate were mixed and heated to 50°C to obtain a uniform mixed solution. This stock solution was treated in the same manner as in Production Example. The obtained original is called i'a'()fi.

Example-l 70X/kOX degreased with trichlene, 1. , After the light surface treatment of the steel plate with L penalty by sandblasting, the base material i! obtained in Production Example/I! A primary primer containing a uniform mixture of ROG and a hardening agent HOG was applied to a uniform thickness using a bar coater boiler boy, and dried in an oven at 10° C. for about 30 minutes. The dry film thickness of the primary brimer at this time was about 1IOμ.

Next, Afj of the secondary primer obtained in Production Example-3 was 10.
0g, Bfi/70g'f: After uniformly mixing, bar coater &/-0'f! After applying it uniformly on the surface using the following method and leaving it for 10 minutes at the mold temperature, the agent was removed by about 10 minutes in an oven at 0.degree. The dry film thickness of the secondary primer at this time is approximately 30
It was μ.

Urethane elastomer stock solution obtained in Production Example-10, Tg3
oog and RQ200g each at 30℃ -10rmx
After defoaming for about 20 minutes under reduced pressure of Hg, mix for about 1 minute using a stirrer to avoid entraining air. After 1 hour, it was heated at gθ°C for 7 hours.

Thereafter, the adhesive was cured for one week at 23° C. and 60% RH (relative humidity).

Method for Measuring Initial Adhesion Strength To measure the initial adhesive strength of an adhesive, make a parallel cut in the longitudinal center of the test piece with a width of λo mx until it reaches the steel plate surface, make a peel-off grip part at one end, and make a 90" Peel strength was measured at a rate of !r Omm/miH in angle.

The peel strength of the test piece showed cohesive failure of the elastomer at 20 hours or more.

Method for Measuring Water Resistant Adhesive Strength The water resistance of the adhesive was evaluated by the following λ tests.

■Temperature gradient test The urethane elastomer side of the test piece mentioned above was brought into contact with hot water at t50°C, and the back side of the adhered steel plate was kept at 23°C with tap water, and after being left for 30 days in a state where the migration of water between the front and back sides was blocked, The 90'' peel strength was measured using the method described above.

■ Hot water immersion test After sealing the ends of the test piece with a sealant,
After being immersed in warm water at a temperature of 0.degree. C. and left for 30 days at a uniform temperature, the 90" peel strength was measured using the method described above.

The results of the adhesion tests are shown in Table C. In all cases, the initial adhesion strength was not higher than JOkg/crn, and cohesive failure of the elastomer occurred, indicating good adhesion.Also, regarding the water-resistant adhesive strength, both the temperature gradient test and the hot water immersion test After 30 days / O
Good adhesion strength of 2011 kg/cm or more was maintained. Water resistant adhesive strength is 20 kl? /cm or more, the elastomer was completely destroyed as was the case at the time of initial adhesion.

Examples 2 to 10 Urethane elastomers were adhered to steel plates in the same manner as in Examples using the primary primer, secondary primer, and urethane elastomer shown in Table 1. The peel strength of the adhesive was measured in the same manner as in Example. The results are shown in Table 1.

The amounts of each compounded component are as follows.

Ku-ji Glimer〉 Main agent Example co-io isog hardening agent
Example 7.10 309 Example g% De
7j? g Secondary Brimer〉 Solution A Example of Solution B loog igog3
9! Tei
tt
tQ5 tt
tt6 〃
〃7 〃
6θ Za // / 70 Ri〃〃 IO // Za 0 <Urethane elastomer> 1st liquid Example-~10 jθop 2nd g Example co~g, 2oon〃 9, /□ it
ol Comparative Example/~3 27g of commercially available Chemlock was applied to a steel plate treated in the same manner as in the example.
(Manufactured by Lord Corporation, phenolic primer) 100g'f: Diluted with methyl ethyl ketone 1009, applied using a bar coater ÷ 100, and heated to 70℃ for 3
After drying for 0 minutes and leaving to cool, apply another layer in the same manner, dry it, and then inject the two-part urethane elanuttomer consisting of the T liquid and R liquid in the same manner as above, harden it, and after 7 hours. 10
After heating at 0° C. for 7 to 3 hours, an adhesive was obtained. The dry film thickness of the brimer at this time was approximately Oμ.

Table 3 shows the results of the adhesion test.

Although the initial adhesion strength is relatively good, the water resistant adhesion shows that after 30 days of hot water immersion test, it was
The results were good when heated for hours, but in the temperature gradient test, the adhesive strength had already been lost after 717 days and the results were poor.

Comparative Example Chemlock 2/g was applied in the same manner to a steel plate treated in the same manner as above, and the steel plate was preheated to 710°C. TD Any00(2,'t-)lylene diisocyanate approx. 700
% content) 2! ;09 I'TM()100θ to 10θo
The Neo concentration obtained by dropping the urethane prepolymer with isocyanate groups at the end of f% was kept at go℃ and defoamed under a reduced pressure of 10m x F1g. Add 30fj7M of Curamine M (manufactured by Ihara Chemical Co., general name: MOOAJ) melted at 20°C, and stir with a stirrer to avoid creating bubbles.
The mixed solution was injected onto a steel plate coated with primer to a thickness of about 6 mm, and cured at 710° C. for an hour. .

As a result of examining the adhesive strength of the obtained adhesive, as shown in Table 3, although the initial adhesive strength was satisfied, the water resistant adhesive strength in the temperature gradient test was extremely poor. [Effects of the Invention] As described above, the present invention According to the present invention, it is possible to obtain an adhesive between a urethane elastomer and a metal that exhibits good adhesive strength in a short ms waiting time, has excellent heat resistance, and has excellent water resistance especially in an environment where a temperature gradient exists.

Mitsubishi Chemical Industries, Ltd.

Claims (1)

[Claims] (1) A primary primer composition containing a polyepoxy compound and a polyamine compound is applied to the metal surface, and an isocyanate compound or a urethane prepolymer having an isocyanate group at the end is applied thereon, containing 5 to 50% by weight of isocyanate groups. A method for adhering a urethane elastomer to a metal, comprising applying a secondary primer composition containing a polyepoxy compound, and then injecting and curing a urethane elastomer stock solution thereon.