JPS62201970A - Water-based adhesive can primer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to a water-based primer coat for adhesive cans. More specifically, it relates to a water-based undercoat that is applied to the can material and functions as a primer in the side seam area by utilizing the adhesion to the polyamide adhesive and the can material.

(Conventional technology) The so-called adhesive can is inside a three-piece can.

A general term for cans whose seams are glued together. The reason behind the increasing importance of adhesives in metal containers in recent years is that instead of conventional tin-plated tin, tin-free steel such as chrome-plated steel sheets and chromic acid-treated steel sheets, as well as nickel-plated steel sheets and aluminum plating are being used. Various can materials such as steel plates and aluminum plates have been developed and supplied. Namely.

These materials cannot be soldered like tin, so
When making the can body of a three-piece can, unlike conventional methods, the ID seam must be joined by welding or adhesive.

When making side seams with adhesive 1. Apply a primer to the can material, usually tin-free steel.

Baking is performed and first, true melt adhesion is performed using a polyamide adhesive. Therefore, the characteristics required of the primer are strong adhesion to the two-can material and adhesive.
At the same time, various physical properties such as corrosion resistance and processability are also required as a paint for the inside of a can. From this point of view, epoxy-phenol solvent-based paints have conventionally been used as primer coats for adhesive cans.

However, in recent years, with the problem of air pollution caused by organic solvents and growing social interest in saving petroleum-based resources, the coating and container industries have started to eliminate the use of organic solvents or reduce the content of organic solvents as much as possible. The transition to new paints is actively being planned. In particular, the primer coat for adhesive cans is a paint that is used in large quantities in adhesive production, and it also has a large effect on adhesive performance. As the production volume of adhesive adhesives increases, the amount of adhesives used also increases, which is why water-based adhesives are strongly desired.

Up to now, epoxy resin-based water-based paints have been mainly studied as water-based can paints, and various methods have been proposed for dispersing epoxy resins in water.

For example, methods using anionic and nonionic surfactants are known as methods for dispersing epoxy resins using surfactants, but storage stability is limited.

It is unsuitable as a paint for cans due to its poor hygienic, chemical and mechanical properties. As a solution to this problem, various self-emulsifying epoxy resins have been proposed in which epoxy resins are modified with acrylic resins and segments with emulsifying power are introduced into the molecules. Since such a self-emulsifying epoxy resin does not contain a surfactant in the coating film, a strong coating film can be obtained by itself. In addition, water-soluble amino resins and phenolic resins are added to these paints when a faster curing speed is required. However, when such prior art is used as an undercoat for adhesive cans, sufficient adhesion to the base can material and polyamide adhesive could not be obtained.

(Problems to be Solved by the Invention) The present researchers have conducted extensive studies in view of the above circumstances, and have found that the performance of conventional epoxy-phenol solvent-based primers, that is, the performance of base materials and polyamide adhesives. By maintaining strong adhesion to the can, it guarantees the hermeticity of the can body and successfully reduces or virtually eliminates organic solvents without impairing the function of the base material as a protective layer from the contents. This is what I did.

(Structure of the Invention) Namely, 2 The present invention is based on 100 parts by weight of a bisphenol type epoxy resin (based on unmodified material (denoted as V)) which is made potentially self-emulsifiable by the carboxyl group introduced into the molecule, and the following ( A composite resin composition obtained by mixing or precondensing 10 to 60 ffift parts of at least one resol resin selected from a), (b), or (c) is at least partially neutralized with an amine or ammonia to form an aqueous solution. This invention relates to an aqueous primer for adhesive cans that is dispersed in a medium.

(a) A resol resin having an ff1ffl average molecular fi of 800 or more and less than 3,000, which is obtained by reacting a mixed phenol of trifunctional or more functional phenol and bifunctional phenol with formaldehyde in the presence of an alkali catalyst.

(b) Weight average molecule Et800 obtained by reacting trifunctional or higher functional phenol and bifunctional phenol individually with formaldehyde in the presence of an alkali catalyst.
A resol resin that is a mixture of resol resins having a molecular weight of less than 3,000.

(c) A resol with an average molecular weight of 9800 or more - less than 3000 obtained by reacting a trifunctional or higher functional phenol with formaldehyde in the presence of an alkali catalyst and reacting a bifunctional phenol in the presence of a resole resin. resin.

(Means for Solving the Problems) As the trifunctional or higher functional phenol used in the resol resin of the present invention, all trifunctional or higher functional phenols conventionally used in the production of resol resins can be used. As a functional phenol, phenol (
carbolic acid) 1m-cresol, m-ethylphenol, 3
, 5-xylenol, m-methoxyphenol, etc. can be used, and examples of the 14-functional phenol include bisphenol A,
Bisphenol B.

Bisphenol F, 1,1-bis(4-hydroxyphenyl)ethane, etc. can be used. Furthermore, all of the difunctional phenols conventionally used in the production of resol resins can be used.

For example, 0-cresol, p-cresol, p-tert
One or two types of bifunctional phenols such as butylphenol, p-ethylphenol, 2,3-xylenol, 2,5-xylenol, I) tert-aminophenol, p-nonylphenol, p-phenylphenol, p-cyclohexylphenol, etc. The above combination is most preferred.

In addition, the alkaline catalysts used in the production of resol + JJ fat include sodium hydroxide monopotassium hydroxide, magnesium hydroxide, basic metal salts, ammonia, hexamethylenetetramine, triethylamine, monohelimethylamine,
There are various conditions for producing resol resin using a phenol and an alkali catalyst such as 9 or higher, preferably an alkaline catalyst such as pyridine, and formaldehyde, but especially when used as a component of a water-based primer for adhesive cans. It is important that the product be manufactured under the following conditions (a), (b), or (c). That is, (a) it is a resol resin obtained by reacting trifunctional or more functional phenols and formaldehyde in the presence of an alkali catalyst so that the weight average molecular weight becomes 800 or more and less than 3,000; (b) trifunctional or more functional ff1 () obtained by reacting phenol and difunctional phenol with formaldehyde in the presence of an alkali catalyst, respectively, with an average molecular weight of 800 or more and 30
(c) A difunctional phenol is reacted in the presence of a resol resin obtained by reacting a trifunctional or higher functional phenol with formaldehyde in the presence of an alkali catalyst. Resole resin with a weight average molecular weight of 1,800 or more and less than 3,000.

Such resol resin (a), (b) or (c)
In this case, it is preferable that the weight ratio of the trifunctional or higher functional phenol to the bifunctional phenol is 50 to 95,150 to 5. In such resol resins, 3
The functional or higher functional phenols give the resin content resistance and corrosion resistance, and the bifunctional phenols give the resin flexibility.

Considering the structure of the resin, it is thought that the crosslinking density is adjusted by the trifunctional or higher functional phenol, and the average distance between the crosslinking points is adjusted by the difunctional phenol. According to each of the resol resin manufacturing methods described in (a), (b), or (c) above, polyfunctional phenols and bifunctional phenols can be connected randomly or in blocks with methylene bonds.

The resol resin obtained in this way has a good balance between processability and adhesion, especially when the weight average molecular weight ff is 1,800 or more and less than 3,000. Performance that could not be achieved before is created.

Here, high performance liquid chromatography was used to measure the weight average molecular weight. Using tetrahydrofuran as the solvent,
The column used was one in which two 5hodex GPCA-80M (trade name: manufactured by Showa Denko K.K.) were connected. Sample concentration 0.15%, injection volume 100μ! , flow rate 1+I
The measurement was carried out under the conditions of Il/win and a differential refractometer as a detector.

Styrene monomer and standard polystyrene A-500, A-1000, A-2500°A-5 were used to create the calibration curve.
000, F-1, F-2, F-4, F-10°F-20
, F-40, and F-80 (manufactured by Toyo Soda Kogyo Co., Ltd.), and the weight average molecular weight was determined as a value in terms of polystyrene.

By using such a resol resin as one of the components of a water-based primer for adhesive cans, it not only improves the initial adhesive strength but also improves the initial adhesive strength of the base material (steel plate such as tin-free steel) - primer - polyamide adhesive structure. Sufficient adhesive strength is maintained even when subjected to processing strain or an aging test in hot water, making it possible to obtain a product with excellent properties as an undercoat for adhesive cans.

In the present invention, the bisphenol type engineered resin used is an epoxy resin made by reacting bisphenols such as bisphenol A, bis 7, nor B, and bisphenol F with epichlorohydrin in the presence of an alkali catalyst. The example is Epicote 828 from Shell Chemical Co., Ltd. Epicote 1001. Epicote 1004. Epicoat 1007, :Cpi] -
G1009. x-bi]-1-1010, etc. Further, dehydrated castor oil fatty acid is added to the epoxy group or hydroxyl group of the above bisphenol type epoxy resin.

It is also possible to use a modified epoxy resin in which a vegetable oil fatty acid such as soybean oil fatty acid or coconut oil fatty acid or a modifier such as bisphenol A is reacted.

In the present invention, the bisphenol-type epoxy resin that is potentially self-emulsifying due to the carboxyl group introduced into the molecule has an average of 0.5 i1M or more epoxy groups per molecule and an average of 0.1 to 1.5 (metal) epoxy groups per molecule. ) It can be obtained by polymerizing a bisphenol type epoxy resin derivative having an acryloyl group and a copolymerizable monomer containing 10 to 80 parts by weight of a monobasic carboxylic acid monomer as an essential component using a radical polymerization initiator. . This epoxy resin derivative is produced by reacting a bisphenol type epoxy resin with methacrylic acid or acrylic acid in the presence of an alkali catalyst such as sodium hydroxide at 100 to 150°C for 1 to 6 hours to form 0.5 epoxy groups per molecule. Average 0.1-I. It can be obtained as having 5 acryloyl groups.

The self-emulsifying bisphenol-type epoxy resin of the present invention can also be prepared by adding a copolymerizable monomer mixture containing from 80% by weight of a monobasic carboxylic acid heptamer flO to an organic ester such as penzoyl peroxide in the presence of a bisphenol-type epoxy resin. It can be obtained by polymerization using a relatively large amount of oxide.

In this case, a bisphenol type epoxy resin grafted with an acrylic resin is obtained.

The self-emulsifying bisphenol type epoxy resin in the present invention also contains 12 to 70 -basic carboxylic acid monomers.
An acrylic resin formed by copolymerizing a copolymerizable monomer mixture containing 1.1 to 2.0% by weight per molecule on average.
It can be produced by partially bonding with a bisphenol type epoxy resin having 0 epoxy groups.

In the production of the above self-emulsifying bisphenol-type epoxy resin, acrylic acid,
Methacrylic acid, etc., is often used as a copolymerizable agent.
Examples include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-acrylate. - Acrylic esters such as octyl, decyl acrylate, dodecyl acrylate, methyl methacrylate, propyl methacrylate, methacrylic 1ln=butyl, isobutyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, n methacrylate - Octyl, methacrylic acid esters such as 2-ethylhexyl methacrylate, decyl methacrylate, and dodecyl methacrylate, styrene, vinyltoluene, 2
-Methylstyrene, t-butylstyrene.

Styrenic monomers such as chlorstyrene, hydroxy group-containing monomers such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, N~methylol (meth)acrylamide, N-butoxymethyl (meth)acrylamide It can be selected from one or more of N-substituted (meth)acrylic monomers such as N-substituted (meth)acrylic monomers, epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, and acrylonitrile.

12 to 70 of the basic carboxylic acid monomers shown above
The copolymerizable monomer mixture containing 10 to 90 parts by weight per 100 parts of bisphenol type epoxy resin
Preferably, parts by weight are used. When the amount is less than 10 parts by weight, it becomes difficult to impart self-emulsifying properties to the epoxy resin, and a stable dispersion cannot be obtained in an aqueous medium. Moreover, if the amount exceeds 901 parts, hydrophilic carboxyl groups remain in the formed coating film, so that the adhesive strength after retort treatment tends to decrease over time, and the corrosion resistance also deteriorates.

In the present invention, the composite resin composition is a mixture of a self-emulsifying bisphenol-type epoxy resin and at least one resol resin selected from the above (a), (b), or (c), preferably in a hydrophilic solvent. It can be obtained by

The amount of resol resin in the composite resin composition must be 10 to 60 parts by weight per 100 parts by weight of the self-emulsifying bisphenol epoxy resin (based on unmodified material). If the amount is less than 10 parts by weight, the curability of the coating film will be poor, and sufficient adhesive strength to the base material or polyamide adhesive will not be obtained. Moreover, if the amount exceeds 60 fi parts, physical properties such as processability of the coating film will deteriorate.

In the present invention, the aqueous resin dispersion can be prepared by adding ammonia or amine in an amount such that the final composition has a pH of 4 to 11 and dispersing it in an aqueous medium. When high boiling point solvents are used, it is preferable to remove these solvents in advance under reduced pressure.

The above amine is, for example, trimethylamine.

Alkylamines such as triethylamine and butylamine, alcohol amines such as 2-dimethylaminoethanol, jetanolamine, triethanolamine, amizmedelpropanol, and 2-morpholine are used. Further, polyvalent amines such as ethylenediamine and deutylenetriamine can also be used. In the present invention, the aqueous medium is at least 50% by weight, preferably 80% by weight or more, and more preferably 1.5% by weight or more. < means a mixture of water, which is 90% by weight, and a hydrophilic organic solvent, and the hydrophilic organic solvents include methanol, ethanol, n-propanol, isopropanol, lobetanol, 5ec-butanol, t,
ert-butanol.

Alkyl alcohols such as isobutanol, ether alcohols such as meb-lucerosolve, ethyl cellosolve, propyl cellosolve, butyl cellosolve, methyl carpitol, ethyl carpitol, ether esters such as methyl cellosolve acetate, ethyl cellosolve acetate, dioxane , dimethylformamide, diaseptone alcohol, etc. are used.

The aqueous resin dispersion according to the present invention can be used as a paint by adding a surfactant, an antifoaming agent, etc. to improve coating properties, if necessary.

Commonly used can materials are untreated steel sheet and treated steel sheet.

Tin-free steel such as galvanized iron plate, tin plate, chromium-plated steel plate and chromic acid-treated steel plate, as well as Ninokerme and
A metal plate such as a laminated steel plate, an aluminized steel plate, or an aluminum plate is passed through, and roll coater painting is preferred as the coating method, but spray painting, dipping painting, electrodeposition painting, etc. are also possible. Also, the baking conditions are temperature 150℃~230℃1
The time can be selected from a range of 2 to 30 minutes.

The present invention will be explained below with reference to examples. In the two examples, "parts" and "%" indicate "parts by weight" and "% by weight," respectively.

(Example) Example 1 [Preparation of resol resin solution] 228 parts of bisphenol A, 108 parts of p-cresol,
203 parts of a 37% formaldehyde aqueous solution and 32 parts of a 25% sodium hydroxide aqueous solution were placed in a flask and heated at 95°C for 6 hours.
It was allowed to react for 0 minutes. The obtained condensation product was mixed with 30 parts of methyl isobutyl ketone (MIBK).

It was extracted with a mixed solvent consisting of 30 parts of cyclohexanone and 40 parts of xylene, and dehydrated by heating and refluxing for 120 minutes, resulting in a weight average molecular weight of 1,410. A resol resin solution with a solid content of 30% was obtained.

The weight average molecular weight of the resol resin was measured by high performance liquid chromatography. Column is Showdex G
PCA-80M (manufactured by Showa Denko K.K.) was used in a two-sided array, and the moving layer was tetrahydrofuran. The sample was diluted with tetrahydrofuran to a solids content of 0.15% and the injection volume was 100. cl, mobile phase flow rate 1m7! /min, and the detector was a differential refractometer.

The weight average molecular weight was determined by dividing the chart obtained above into minute parts and using the following formula.

I]i Here, H4: Size of response in 4 categories ff1Hi: Total of all responses M i : Molecular weight in 4 categories The calibration curve used to determine the molecular weight in each 1 category is a standard polystyrene equivalent manufactured by Toyo Soda Kogyo Co., Ltd. is the value of

[Preparation of self-emulsifying bisphenol type epoxy resin] 200 parts of Epicote 1007 and 70 parts of butyl cellosolve were placed in a flask and dissolved, and then 0.15 part of a 25% aqueous potassium hydroxide solution was added and the temperature was raised to 120°C. Add 7.5 parts of acrylic acid to this and raise the temperature of the liquid in the flask to 12
The mixture was added dropwise over 120 minutes while being kept at 0°C. After the dropwise addition was completed, the mixture was cooled and taken out to obtain a compound having an average acid value of 0.3° and one epoxy group and one acryloyl group per molecule.

100 parts of this compound, 35 parts of styrene, 1 part of methacrylic acid
5 parts, 20 parts of methyl methacrylate, 00.4 parts of azobisisobutyronitrile, and 80 parts of n-butanol were added and mixed uniformly.

50 parts of this mixed solution was placed in a flask and heated to 90°C. The remaining mixture was added dropwise over 120 minutes while keeping the liquid temperature in the flask at 90°C. After the completion of FB, the reaction was continued for an additional 180 minutes. In this way, a potentially self-emulsifying bisphenol-type epoxy resin was obtained due to the carboxyl group introduced into the molecule.

[Preparation of aqueous dispersion]

348 parts of the above self-emulsifying epoxy resin solution (100 parts of unmodified epoxy resin) and 174 parts of the above resol resin solution
(52.2 parts as resin content) was placed in a flask, stirred, and neutralized by adding 13 parts of 2-dimethylaminoethanol. Thereafter, the temperature was raised to 80°C, reacted for 30 minutes, and then cooled. After cooling, add ionized water 7 while stirring.
When 30 parts were gradually added, 2 solids content was 20% and viscosity was 4.
．． A milky dispersion of 30 cps was obtained. The obtained dispersion was stored at 50°C for 3 months, but no abnormalities were observed.

Example 2 [Preparation of resol resin solution] 8242 parts of bisphenol, 203 parts of 37% formaldehyde aqueous solution, and 14 parts of 25% aqueous ammonia were placed in a flask and reacted at 65° C. for 180 minutes.

Subsequently, 54 parts of 0-cresol was added and heated at 95°C for 30 minutes.
Allowed to react for minutes. The obtained condensation product was extracted with a mixed solvent consisting of 30 parts of M I 13, 30 parts of cyclohexanone, and 40 parts of xylene, and dehydrated by heating and refluxing for 120 minutes to give a weight average molecular weight of 1350.30. % solids resol resin solution was obtained.

[Preparation of aqueous dispersion]

348 parts of the self-emulsifying epoxy resin of Example 1 (100 parts of unmodified epoxy resin) and the above resol resin solution 17
4 parts (52.2 parts as resin content) was placed in a flask, stirred for 1 hour, and 13 parts of 2-dimethylaminoethanol was added for 2 hours to effect neutralization. Thereafter, the temperature was raised to 80'C, reacted for 30 minutes, and then cooled. After cooling, 730 parts of ion-exchanged water was gradually added while stirring, resulting in a solid content of 20
%, a milky white dispersion with a viscosity of 390 cps was obtained. The obtained limbs were stored at 50'C for 3 months, but no abnormalities were observed.

Example 3 [Preparation of resol resin solution] 72 parts of carbolic acid, 157 parts of 37% formaldehyde aqueous solution, and 10.6 parts of 25% aqueous ammonia were placed in a flask.
The reaction was carried out at 5°C for 60 minutes. The obtained condensation product was MIB
45 parts of K, 45 parts of cyclohexanone.

It was extracted into a mixed solvent consisting of 60 parts of xylene, and dehydrated for 120 minutes by heating and refluxing to obtain 1 weight average molecule of 4.
71820. A resol resin solution (a) with a solid content of 30% was obtained.

50 parts of p-terL-butylphenol, 195 parts of 37% formaldehyde aqueous solution, 1 part of 25% aqueous ammonia
3.6 parts were charged into a flask and reacted at 95°C for 60 minutes. The resulting condensation product was extracted into a mixed solvent consisting of 30 parts of MIBK, 30 parts of cyclohexanone, and 40 parts of xylene, and dehydrated by heating under reflux for 120 minutes.
Weight average molecular weight 2050. A resol resin solution (b) with a solid content of 30% was obtained.

The resol resin solution (a) and the resol resin solution (b) were mixed at a weight ratio of 1:1 to obtain a mixed resol resin solution.

[Preparation of aqueous dispersion]

348 parts of the self-emulsifying epoxy resin solution of Example 1 was placed in a flask and stirred, followed by 1 part of 2-dimethylaminoethanol.
Neutralization was carried out by adding 3 parts. Thereafter, the temperature was raised to 80°C, reacted for 30 minutes, and then cooled. When 730 parts of ion-exchanged water was gradually added dropwise while cooling, the solid content was 20%.
A milky white dispersion with a viscosity of 520 cps was obtained. The obtained dispersion was stored at 50°C for 3 months, but no abnormalities were observed.

Example 4 [Preparation of aqueous resin dispersion] Epicote 1009 too part and ethyl cellosolve 6
After 7 parts were charged into a flask and dissolved, the liquid temperature was raised to 115° C. without stirring. After dissolving 3.0 parts of hendyl peroxide in a mixed solution of 30 parts of methacrylic acid, 20 parts of styrene, and 10 parts of ethyl acrylate, the entire amount was dissolved over 60 minutes while maintaining the liquid temperature at 110 to 120°C. dripped. After further reacting at 115°C for 12,020 minutes, it was cooled to 8
83 parts of the resol resin solution of Example 1 (50.1 parts as resin content) and 4.2 parts of 2-dimethylaminoethanol at 0°C.
8 parts were added.

After thorough stirring, 600 parts of ion-exchanged water was gradually added to obtain a stable aqueous dispersion.

Comparative Example 1 [Preparation of resol resin solution] 228 parts of bisphenol A, 108 parts of p-cresol,
203 parts of a 37% formaldehyde aqueous solution and 14 parts of 25% aqueous ammonia were charged into a flask and reacted at 95°C for 35 minutes. The resulting condensation product was extracted into a mixed solvent consisting of 30 parts of MIBK, 30 parts of cyclohexanone, and 40 parts of xylene, and dehydrated for 80 minutes by continuous heating.
A resol resin solution having a weight average molecular weight i710 and a solid content of 30% was obtained.

[Preparation of aqueous resin dispersion]

348 parts of the self-emulsifying epoxy resin solution of Example 1 (100 parts of unmodified epoxy resin) and the above resol resin layer?
Fi, 174 parts (resin content: 52.2 parts) was placed in a flask, stirred, and then neutralized by adding 7.5 parts of 2-dimethylaminoethanol. Then raise the temperature to 80℃ 3
After reacting for 0 minutes, the mixture was cooled. 6.60 parts of ion-exchanged water was gradually added while cooling.

A milky-white limb with a solid content of 23% and a viscosity of 380 cps was obtained. The obtained dispersion was stored at 50"e for 3 months, but no abnormalities were observed.

Comparative Example 2 [Preparation of resol resin solution] 150 parts of p-tert-butylphenol, 108 parts of 0-cresol, 130 parts of 37% formaldehyde.

Using 14 parts of 25% ammonia water and using the same method as in Example 1, the molecular weight was 1180. A resol resin solution with a solid content of 30% was obtained.

[Preparation of aqueous resin dispersion]

Using the self-emulsifying epoxy resin of Example 1 and the resol resin described in "-", the same procedure as in Example 1 was carried out to obtain a solid content of 20%,
A milky white dispersion with a viscosity of 390 cps was obtained.

Comparative Example 3 [Preparation of aqueous resin dispersion] 348 parts of the self-emulsifying epoxy resin solution of Example 1 (unmodified epoxy resin content: 100 parts) and 26 parts of the resol resin solution of Example 1 (resin content: 7.8 parts) Using the same method as in Example 1, 1 zt of a milky white dispersion having a solid content of 20% and a viscosity of 610 cpS was prepared.

Comparative Example 4 [Preparation of aqueous resin dispersion] 348 parts of the self-emulsifying epoxy resin solution of Example 1 (100 parts of unmodified epoxy resin) and 350 parts of the resol resin solution of Example 2 (105 parts of resin) were used.

Solid content 20%, viscosity 350 cp using the same method as Example 1
A dispersion of s was obtained.

Examples 1-4. The aqueous resin dispersions obtained in Comparative Examples 2 to 4 were coated on a 0.17 ui thick high top (manufactured by Toyo Kogan Co., Ltd.) using a roll coater, and then baked and dried at 200° C. for 10 minutes. The coating amount was 50 mg/dm.

- A 1,2-aminolauric acid polymer (relative viscosity 2.3) film was sandwiched between the coated plates labeled F, and the film was heated to 200℃ for 10 minutes.
After being compressed with a hot press for seconds and cooled, 15 bonded samples were cut at 5 am during bonding. This was subjected to a T-peel test using a Schopper tensile strength tester at ambient temperatures of 25°C and 120°C. The results are shown in the table below.

Example 1 5.1 2.2 4.8 4.4
4.1 Example 2 5.4 2°45.2 4.
9 4.7 Example 3 4.9 2.0 4.8
4.0 3.9 Example 4 5.0 2.2
4.7 4°24.2 Comparative Example 1 2.6 1.
1 2゜2 1.8 1.6 Comparative example 2 1.6
0.9 1.2 0.9 1.3 Comparative example 3
2.7 1.4 2.2 1.9 2.01
) The adhesive sample was placed in hot water at 95°C for 15 hours and 45 hours.
After being immersed for a period of time, it was cooled and dried, and a 'r type 1-11 release test was conducted at 25°C.

2) After bending one part of the adhesive sample in an 8-inch
An 'r-type peel test was conducted at ゛C.

〔Effect of the invention〕

The adhesive can primer of the present invention can form a stable resin dispersion even in an aqueous medium containing 90% by weight or more of water in the coating solvent.

Furthermore, since a resol resin with excellent adhesiveness is used, it has extremely high adhesiveness to the base material and polyamide adhesive.

Claims (1)

[Scope of Claims] 1. The following (a) for 100 parts by weight of a bisphenol-type epoxy resin (based on unmodified material) that is made potentially self-emulsifying by the carboxyl group introduced into the molecule:
A composite resin composition obtained by mixing or precondensing 10 to 60 parts by weight of at least one resol resin selected from (b) or (c) is at least partially neutralized with an amine or ammonia, and then placed in an aqueous medium. A water-based primer for adhesive cans that is dispersed in (a) A weight average molecular weight of 80 obtained by reacting a mixed phenol of trifunctional or higher functional phenol and bifunctional phenol with formaldehyde in the presence of an alkali catalyst.
Resol resin with a molecular weight of 0 or more and less than 3,000. (b) A resol resin in which a resol resin having a weight average molecular weight of 800 or more and less than 3,000 obtained by individually reacting a trifunctional or more functional phenol and a bifunctional phenol with formaldehyde in the presence of an alkali catalyst is mixed. (c) A resol resin having a weight average molecular weight of 800 or more and less than 3,000, obtained by reacting a bifunctional phenol in the presence of a resol resin obtained by reacting a trifunctional or higher functional phenol with formaldehyde in the presence of an alkali catalyst. 2. Claim 1, wherein in the resol resin (a), (b) or (c), the blending ratio of trifunctional or higher functional phenol to bifunctional phenol is 50 to 95/50 to 5 by weight. Water-based adhesive can primer as described.