JP2622804B2 - Aqueous resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin composition and can be used mainly as a paint, a primer, an ink, an adhesive, and a sealing agent. In addition, the resin composition of the present invention can be used in combination with other aqueous resins such as aqueous urethane, acrylic, polyester, and epoxy, and a water-soluble resin depending on the application, so that it can be used as a modifier for a film-forming material. Can also be used.

[0002]

2. Description of the Related Art Conventionally, polypropylene, polyethylene,
And propylene, a modified polyolefin composition obtained by modifying a polyolefin such as a copolymer of ethylene and an α-olefin with an unsaturated carboxylic acid and / or an acid anhydride, and an acid-modified chlorinated polyolefin obtained by chlorinating them is a coating material. Used for primers, inks, etc. However, at present, these resins are soluble only in aromatic organic solvents such as toluene and xylene, so that a large amount of aromatic solvents must be used, which is a problem in terms of safety and health and environmental pollution.

[0003] Attempts have been made to produce aqueous dispersions of chlorinated polyolefins.
153778 JP, JP-A-1-256556, JP-A-2-284973
However, these compounds use an aromatic organic solvent at the time of production, and it is difficult to completely eliminate them.

Attempts have also been made to produce aqueous dispersions of modified polyolefins, for example, as disclosed in JP-A-59-47244.
And JP-A-2-286724. However, when the object to be coated and the object to be bonded are polyolefin resin in coating, bonding, etc., there are drawbacks such as poor adhesion and poor water resistance or poor paintability, and such an aqueous composition is still in practical use. Has not been reached.

In Japanese Patent Application Laid-Open No. Hei 3-182534, the modified chlorinated polyolefin is made aqueous using a surfactant, and an aqueous polyurethane resin is blended to improve the coating film performance. However, water-soluble urethane resin,
Since the surfactant is not reactive, the activator component is eluted from the coating film by water, which causes a phenomenon that the water resistance is reduced due to a defect of the coating film which is considered to be caused by the elution. In addition, reactive surfactants have been used in emulsion polymerization so far, have a surfactant activity for suspending monomers in water in emulsion polymerization, and react with other monomers to form a polymer. Was incorporated into the structure, resulting in the effect of improving the water resistance of the reactants

[0006] Aqueous blocked isocyanates are generally used for fiber processing, for crosslinking and modifying resins such as latex, acrylic and urethane, and for surface processing of plastic films. However, there is no report that found a new use and characteristic by combination with an aqueous polyolefin resin.

[0007]

As described above, since the conventional modified polyolefin composition is used as an organic solvent solution, there have been problems of solvent toxicity and environmental problems. In addition, an aqueous resin composition using a surfactant devised to solve these problems has conventionally had a problem of water resistance. It is an object of the present invention to provide an aqueous resin composition which solves these toxicity, environmental problems, poor water resistance of the coating film, and at the same time.

It is another object of the present invention to improve the water resistance of a water-based resin composition of a polyolefin or a modified polyolefin without impairing the adhesion and adhesion of a film formed by the water-based resin composition to a substrate.

[0009] The present inventors for achieving the object toxicity, no problems such as pollution surface, a result of intensive studies of an aqueous resin composition excellent in excellent and waterproof safety, modified poly
Olefin resin, blocked isocyanate compound, interface
It has been found that the object can be achieved by using an aqueous resin composition containing an activator, and the present invention has been accomplished.

The modified polyolefin used in the present invention is:
A modified polyolefin resin comprising one or more of a polyolefin modified by graft copolymerization of an unsaturated carboxylic acid or acid anhydride , a chlorinated polyolefin, and a polyolefin graft-copolymerized with a reactive monomer.

Further, a modified polyolefin resin obtained by performing at least two types of modification by acid modification, chlorination modification, and modification with a reactive monomer can also be used. In addition, modified polyolefin resin and block isocyanate
It is effective to add a surfactant and an alcohol to the anate .

The polyolefin used in the present invention is a homopolymer of ethylene or propylene, or ethylene or propylene and another comonomer such as butene.
1, pentene-1, hexene-1, heptene-1, octene-1 and the like having 2 or more carbon atoms, preferably 2 to 6 carbon atoms.
It is a random copolymer or a block copolymer with an olefin comonomer, and a random copolymer is more preferable than a block copolymer. In addition, these comonomers are
More than one kind may be copolymerized.

When a film is formed on a polypropylene substrate, the proportion of the propylene component is preferably at least 55 mol%, and if it is less than 55 mol%, the adhesion to the surface of a non-polar substrate such as polypropylene is inferior.

The chlorinated polyolefin is obtained by chlorinating the above polyolefin by a known method. The acid-modified polyolefin is a polyolefin obtained by modifying the above polyolefin by a graft reaction with an α, β-unsaturated carboxylic acid or an acid anhydride thereof.

Α, β used for modification of polyolefin
-Examples of unsaturated carboxylic acids or acid anhydrides thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid, allylsuccinic acid, mesaconic acid, aconitic acid, and acid anhydrides thereof.

The amount of the α, β-unsaturated carboxylic acid or its anhydride to be graft-copolymerized is preferably from 1 to 20% by weight, and if it is less than 1% by weight, the stability when dispersed in water deteriorates. Exceeding the weight% is uneconomical due to poor grafting efficiency. Particularly preferably, 2 to 15% by weight
It is.

The number average molecular weight of a resin obtained by graft copolymerizing an α, β-unsaturated carboxylic acid or an acid anhydride thereof is 3
When it is more than 35,000, the cohesive strength is insufficient and the adhesion to the polyolefin resin becomes poor. When it exceeds 35,000, the operability when dispersing in water is unfavorably deteriorated. In order to make the molecular weight fall within this range, it is possible to select the molecular weight of the raw material and the conditions for performing the graft reaction, and it is also possible to perform the graft reaction after the molecular weight of the raw material is reduced. The number average molecular weight can be measured by GPC (gel permeation chromatography).

The method of graft-copolymerizing an α, β-unsaturated carboxylic acid or an acid anhydride thereof with a polyolefin may be carried out by a known method. It is preferable to carry out by a method of graft copolymerization with

In the present invention, a modified polyolefin resin and
Surface activity in making block and isocyanate aqueous
Add an active agent and, if necessary, alcohols.
Addition of basic substances and radical reaction initiators
Can also.

The basic component is added to ionize hydrophilic groups such as a carboxyl group and a sulfone group to improve dispersion in water, and to use a reactive surfactant and a non-reactive surfactant to be used. In some cases, it is not necessary to use the agent when the agent is already neutralized with a base.

As the base, sodium hydroxide, potassium hydroxide, ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N-methyldiethanolamine, dimethylamine, diethylamine, Triethylamine,
N, N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-
Examples thereof include methyl-1-propanol and morpholine. The degree of hydrophilicity of the resin also varies depending on the type of base used, so it is necessary to select it appropriately depending on the conditions.

The amount of the basic substance used is suitably in the range of 0.3 to 1.5 times the equivalent of the carboxyl group of the acid-modified polyolefin, and preferably 0.5 to 1.2 times. In addition, in the case of adding a basic substance, it may be necessary to control the pH of the aqueous resin composition, which is adjusted by the stability of the blocked isocyanate compound to be mixed, to around neutrality.

In the present invention, the monoalcohol or polyol, which is an alcohol, is added to increase the affinity of the raw resin for water, and this effect can reduce the amount of the reactive surfactant used. Furthermore, it is possible to increase the evaporation rate of water at the time of forming a coating film.

However, if alcohol remains in the resin at the time of film formation, the water resistance of the coating film is reduced, so it is necessary to add an appropriate amount.
Preferably, 200 parts are added. If it is less than 4 parts, the dispersibility in water is poor, and if it exceeds 200 parts, the water resistance is significantly reduced.

Examples of the monoalcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, ethylene glycol monoalkyl ether, ethylene glycol monoacetate, propylene glycol monoalkyl ether, and propylene glycol monoalkyl. Acetate and the like are exemplified, and examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol, glycerin, polyethylene glycol and the like. Among them, a polyol having strong hydrophilicity is desirable.

The surfactant used in the present invention and
Is a reactive and / or non-reactive surfactant
That means. As the reactive surfactant, those generally used as a reactive surfactant or a reactive emulsifier may be used, but those having an alkylphenyl group as a hydrophobic group and a polyoxyethylene group as a nonionic hydrophilic group are preferable. Among them, alkylpropenyl phenol ethylene oxide 20 mol adduct, 30 mol adduct, 50 mol
Molar adducts (Aqualon RN-20, RN-30, RN
-50, Daiichi Kogyo Seiyaku) and ammonium sulfate salts of alkylpropenyl phenol polyethylene oxide 10 mol adduct, sulfate ammonium salt of the same 20 mol adduct (Aqualon HS-10, HS-20,
Daiichi Kogyo Seiyaku), 1-alkylphenoxy-3- (2-
Propenyl) oxy-propan-2-ol ethylene oxide adduct or sulfate thereof (Riasoap NE)
-10, NE-20, NE-30, NE-40, SE-
10N; manufactured by Asahi Denka Kogyo).

Further, non-reactive surfactants that can be used include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether,
Nonionic surfactants such as polyoxyethylene fatty acid ester, polyoxyethylene polyhydric alcohol fatty acid ester, polyoxyethylene propylene polyol (pluronic type), alkylolamide, sorbitan alkyl ester, polyglycerin ester, alkyl sulfate ester salt, alkyl phenol Anionic surfactants such as sulfonates and sulfosuccinates, as well as carboxylate and phosphate salts, amphoteric surfactants such as alkyl betaines and alkylimidazolines, and two types of these A mixture of the above can be used.

The amount of the surfactant component, which is a combination of the non-reactive surfactant and the reactive surfactant, is determined by the amount of the modified polyolefin 1
The amount is 1 part to 100 parts with respect to 00 parts, and the required amount varies depending on the combination and the amount ratio of the surfactant component, the added amount of the alcohol component, and the type and amount of the reactive monomer.

The reactive monomer which can be used in the present invention includes acrylic acid, methacrylic acid, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, acrylonitrile, acrylamide, hydroxyethyl acrylate and the like. Acrylic monomers, conjugated diene monomers such as butadiene, isoprene, and chloroprene; halogenated olefin monomers such as vinyl chloride and vinylidene chloride; aromatic monomers such as styrene and divinylbenzene; vinyl ester monomers such as vinyl acetate; and maleic acid Methyl and maleic anhydride.

The reaction initiator for initiating the reaction between the reactive monomer and the reactive surfactant may be a known one, and may be a water-soluble initiator such as azobisisobutyronitrile, hydrogen peroxide, potassium persulfate. But oil soluble initiators can be used. Further, a redox-based initiator can be used. They may be used in combination.

As the organic peroxide, for example, benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, 2,5-dimethyl-2,5-di (t-
(Butylperoxy) -hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, t
-Butylperoxybenzoate, cumene hydroperoxide and the like, which are selected and used depending on the reaction temperature and reaction time.

The aqueous blocked isocyanate compound in the present invention has an isocyanate group in its molecular structure, and the isocyanate group is blocked by an appropriate blocking agent, and is itself water-soluble or water-dispersible. Alternatively, it refers to a material which has not been water-soluble or water-dispersible itself but has been made water-soluble by any method such as addition of a surfactant or formation of a hydrophilic protective colloid.

Blocked isocyanate is defined as 2 per molecule.
Isocyanate compounds having at least two isocyanate groups, for example, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6 -Tolylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4 ', 4 "-triphenylmethane triisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,
Isocyanates such as 4'-diphenylene diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, isophorone diisoanate, lysine isocyanate, and an excess of the isocyanate compound;
For example, ethylene glycol, propylene glycol,
Low molecular weight polyols such as 1,3-butylene glycol, neopentyl glycol, 2,2,4-trimethyl 1,3-pentanediol, hexamethylene glycol, cyclohexanedimethanol, trimethylolpropane, hexanetriol, glycerin, and pentaerythritol; Is an isocyanate compound obtained by blocking a polyisocyanate having two or more functions, a polyisocyanate having a burette structure, a polyisocyanate having an allophanate bond, an isocyanate having a nullate structure, or the like obtained by an addition reaction or an addition polymerization reaction with a blocking agent. Examples of the blocking agent include phenols such as phenol and cresol, alcohols such as methanol, benzyl alcohol and ethylene glycol monomethyl ether, active methylenes such as methyl acetoacetate and dimethyl malonate, and acid amides such as acetanilide and acetate amide. And imides, amines, imidazoles, ureas, carbamates, imines, oximes, mercaptans, sulfites, lactams and the like. That is, the blocked isocyanate referred to in the present invention includes a compound generally called a blocked isocyanate, a masked isocyanate, a reactive urethane or the like.

The ratio of the blocked isocyanate compound to the modified polyolefin is preferably in the range of 1:20 to 10: 1. However, the content of the isocyanate group contained in the blocked isocyanate compound, the modified polyolefin, the surface active component, etc. The optimum ratio can be determined according to the amount of the functional group which reacts with the isocyanate group such as the hydroxyl group and the carboxyl group contained in the component remaining in the coating film.

In the aqueous resin composition of the present invention, it is effective to dissociate the blocking agent after water evaporates in the drying step. Therefore, the dissociation temperature of the blocking agent is preferably higher than the temperature set in the drying step. .

The blocked isocyanate is not necessarily water-dispersible or water-soluble per se, as long as it is made water-soluble by a water-miscible organic solvent or a surfactant.

In the aqueous resin composition of the present invention, a dissociation catalyst for accelerating the deblocking reaction can be used, if necessary.

In the present invention, in the step of adding and blending the blocked isocyanate to the modified polyolefin resin, the modified polyolefin resin is dissolved in a solvent and the blocked isocyanate compound is added to the solution. Or an aqueous modified polyolefin resin and an aqueous blocked isocyanate compound.

The resin composition of the present invention dispersed in water in this way has excellent adhesion to polyolefins, and is excellent not only as a primer for painting and bonding, but also as a vehicle resin for aqueous coatings, aqueous adhesives. And a binder resin for aqueous inks. Furthermore, the aqueous resin composition of the present invention may optionally contain a rust-preventive pigment,
Pigments such as color pigments and extenders, and various additives such as flow aids, surface conditioners, primary rust inhibitors, defoamers, preservatives, and fungicides can also be added and mixed in necessary amounts.

Further, another aqueous resin, for example, an aqueous resin such as a urethane resin, an epoxy resin, an acrylic resin, a phenol resin, an amino resin, a polybutadiene resin, an alkyd resin, and a silicone resin may be blended.

When a film is formed using the aqueous resin composition of the present invention, heat treatment is carried out at 80 to 200 ° C. for 1 minute to 2 hours in order to deblock and promote the reaction between isocyanate and other active hydrogen at the time of film formation. The optimum value of the treatment conditions is set according to the deblocking conditions of the blocked isocyanate to be used, the type and the amount of the deblocking catalyst to be used.

[0042]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Prototype Example-1) In a four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, a propylene-α-olefin copolymer (propylene component 75 mol%, ethylene component 20 mol% 5 mol% of 1-butene component,
300 g of toluene was dissolved in 700 g of toluene by heating. Then, 13 g of maleic anhydride and 12 g of di-t-butyl peroxide as a radical generator were added to the system for 2 hours while maintaining the temperature of the system at 115 ° C. with stirring. And let it drip,
Thereafter, aging was performed for 3 hours. After the reaction, the reaction product was cooled to room temperature, and then poured into 20 L of acetone for purification.
A 2.1% by weight maleic anhydride graft copolymer was obtained.

(Trial Production Example-2) In a four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel, a propylene-butene-ethylene copolymer (propylene component 68 mol%, butene component 24 mol%) After heating and dissolving 300 g, 40 g of maleic anhydride and 5 g of dicumyl peroxide as a radical generator were added for 3 hours while stirring while maintaining the temperature of the system at 180 ° C. Then, the reaction was carried out for 3 hours. After cooling to room temperature after the reaction, the reaction product was poured into 20 L of acetone and purified to obtain a maleic anhydride graft copolymer having a graft amount of 9.2% by weight. The weight average molecular weight measured by GPC was 26,000.

In the measurement of the weight average molecular weight, a column TSK-GEL was attached to HPLC-8020 manufactured by Tosoh Corporation, the sample was dissolved in THF (tetrahydrofuran), the measurement was performed at 40 ° C., and the molecular weight was determined from a calibration curve prepared with a polystyrene standard sample. I asked.

Example 1 In a four-necked flask similar to that of Trial Production Example 1, 100 g of the maleic anhydride graft copolymer obtained in Trial Production Example 1 was heated and melted at 120 ° C., and 10 g of ethylene glycol was melted. After adding 15 g of morpholine, 1-alkylphenoxy-3- (2-propenyl) oxypropane-2
10 g of an all-ethylene oxide adduct (Adecaria soap NE-10; manufactured by Asahi Denka Kogyo) was added, and
The temperature was lowered to 90 ° C., and water at 90 ° C. was gradually added to prepare an aqueous reaction solution. Sodium persulfate 10 as a radical reaction initiator
g was added and the reaction was carried out at 80 ° C. for 4 hours with stirring to carry out a polymerization reaction. After the reaction, triethyleneamine 4
g was added to obtain an aqueous solution (solid content: 30%). The aqueous solution was treated with an ultrafiltration membrane having a molecular weight cut-off of 5,000 for 48 hours and then concentrated again to obtain an aqueous acid-modified polyolefin resin having a solid content of 45%. The obtained aqueous acid-modified polyolefin resin and aqueous blocked isocyanate (Elastron BN-69, manufactured by Daiichi Kogyo Seiyaku) were mixed at a solid content of 2: 1 to obtain an aqueous resin composition.

(Example 2) In a four-necked flask similar to that of Trial Production Example 1, 100 g of the maleic anhydride graft copolymer obtained in Trial Production Example 2 was heated and dissolved in 200 g of toluene at 110 ° C. Butyl peroxyisopropyl carbonate 10
g and 9.6 g of morpholine, and a solution of 10 g of an alkylpropenylphenol ethylene oxide 20 mol adduct (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Aqualon RN-20) in toluene (120 g) was added dropwise over 3 hours. By doing so, a graft copolymerization reaction was performed. After the toluene contained in the reaction solution was distilled off under reduced pressure, 4 g of triethylamine and 20 g of propylene glycol monomethyl ether were added, and water was added with stirring to obtain an aqueous reaction solution (solid content: 25%). The aqueous reaction solution was treated with an ultrafiltration membrane having a molecular weight cutoff of 5,000 for 48.
After being treated for an hour, the solution was re-concentrated to obtain an aqueous acid-modified polyolefin resin having a solid content of 40%. Graft amount is 45% by weight based on raw resin
Met. An aqueous blocked isocyanate (Elastron BN-08,
(Daiichi Kogyo Seiyaku Co., Ltd.) was added at a ratio of 2: 1 in solid content to obtain an aqueous resin composition.

Example 3 100 g of the maleic anhydride graft copolymer obtained in Prototype Example 2 was heated and dissolved at 110 ° C. in a four-neck flask similar to that of Prototype Example 1, and ethanol 40
g, polyethylene oxide nonylphenyl ether (NS-212, manufactured by NOF Corporation), 5 g, and morpholine 9.6 g
After the addition, the aqueous acid-modified polyolefin resin composition (solid content
45%). An aqueous blocked isocyanate (Coronate 2507) is used for this aqueous modified polyolefin resin.
W, manufactured by Nippon Polyurethane) at a solids ratio of 4: 3 to obtain an aqueous resin composition.

(Example-4) Chlorinated polypropylene resin Supercron 803MW (manufactured by Sanyo Kokusaku Pulp Co., Ltd., chlorine content 29.5%, solid content wt% 20% toluene solution)
After heating 500 g to 110 ° C. and adding 9.6 g of morpholine, 5 g of polyethylene oxide nonylphenyl ether (NS-212, manufactured by NOF Corporation) was added. After the Toern was distilled off under reduced pressure, 20 g of ethylene glycol was added, and water was added with stirring at 100 ° C. to obtain an aqueous resin composition (solid content: 40%).
%). The obtained aqueous acid chlorinated polyolefin resin and aqueous blocked isocyanate (Elastron BN-4)
4, manufactured by Daiichi Kogyo Seiyaku) at a solid content of 2: 1 to obtain an aqueous resin composition.

(Example-5) A polyolefin obtained by oxidatively reducing the raw material polyolefin used in Prototype Example-2 (MW = 30)
000), a low-viscosity acid-modified polyolefin resin (MW = 12000, graft amount 9.6 wt.
%) Acid-modified polyolefin resin obtained using
Is dissolved in 200 g of toluene at 60 ° C., 50 g of TDI-based blocked isocyanate (Desmodur BL1100, manufactured by Sumitomo Bayer Urethane) is added, and then polyethylene oxide nonyl phenyl ether (NS-21, manufactured by NOF Corporation)
2) 5 g was added. After the toluene was distilled off under reduced pressure, 20 g of ethylene glycol was added, and water was added with stirring at 100 ° C. to obtain an aqueous resin composition (solid content: 40%).

Comparative Example 1 100 g of the maleic anhydride graft copolymer obtained in Prototype Example 2 was heated and dissolved at 110 ° C. in a four-necked flask similar to that of Prototype Example 1 to obtain morpholine 9.6.
After adding g, 15 g of polyethylene oxide nonyl phenyl ether (NS-212, manufactured by NOF Corporation) was added.
While stirring, water is added to the aqueous resin composition (solid content 40
%).

(Comparative Example 2) Chlorinated polypropylene resin Supercron 803 MW (manufactured by Sanyo Kokusaku Pulp Co., Ltd., chlorine content 29.5%, solid content wt% 20% toluene solution)
After heating 500 g to 110 ° C. and adding 9.6 g of morpholine, 15 g of polyethylene oxide nonylphenyl ether (NS-212, manufactured by NOF Corporation) was added. After the toluene was distilled off under reduced pressure, water was added while stirring at 100 ° C. to obtain an aqueous resin composition (solid content: 40%).

(Comparative Examples -3 to 4) Nonionic ester-based aqueous urethane resin Superflex 110 was used instead of the aqueous blocked isocyanate for 100 g of the aqueous acid-modified polyolefin resin solids prepared in Examples 1 and 2.
(Daiichi Kogyo Seiyaku) was added in a predetermined amount, and water was added with stirring to obtain an aqueous resin composition having a solid content of 45%.

The aqueous dispersions of Examples 1 to 5 and Comparative Examples 1 to 4 were subjected to a stability test after standing for one month by the following method. The results are shown in Table 1.

Storage stability test A prepared aqueous resin composition sample (solid content: 25%) was placed in a glass container having a capacity of 250 ml, and at room temperature, the degree of separation of the aqueous phase from the emulsion phase to the upper portion, and formation of resin aggregates The changes over time were compared.

Next, the aqueous resin compositions prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were spray-coated on a polypropylene plate and dried at 80 ° C. for 15 minutes. The film thickness was adjusted to 10 to 15 μm. Next, apply a two-component urethane top coat,
After leaving at room temperature for 10 minutes, use a hot air drier at 80 ° C for 30 minutes.
After the forced drying for 2 minutes, heat treatment was performed at 120 to 130 ° C. for 2 to 15 minutes. After the obtained coated plate was allowed to stand at room temperature for one day, the following adhesion test, gasoline resistance test, water resistance test and bending resistance test were performed. The results are shown in Table 1.

Adhesion test A cut was made on the surface of the coating film to reach the substrate with a cutter, and 100 gobangs were made at 1 mm intervals, and a cellophane adhesive tape was adhered on it and peeled off 180 times in the direction of 180 degrees. I counted the number of Goban eyes.

Gasoline Resistance Test A cut was made on the surface of the coating film to reach the substrate with a cutter, and the coating film was immersed in gasoline (Nisseki, high octane gasoline) for 4 hours, and the state of the coating film was visually observed.

Water resistance test The coated plate was immersed in warm water of 40 ° C. for 48 hours to examine the state of the coating film.

Bending resistance test The coated plate was bent 180 ° with a 1φ inch mandrel, and the state of the coating film was examined.

[0061]

[Table 1] (Symbols in the table) ：: very good, ：: good, Δ: slightly bad, ×: bad, XX: very bad

[0062]

The step of adding water to the modified resin by using a blocked isocyanate in which an isocyanate group which reacts with water is blocked, and making the modified resin aqueous, and the step of applying and drying the aqueous resin composition on a substrate, It does not react with water, and is heat-treated at a high temperature after drying, or is deblocked and heat-treated at a high temperature of 100 ° C. or more after overcoating with other film-forming components to activate isocyanate groups. The activated isocyanate group reacts with a surfactant, a modified polyolefin, a hydroxyl group, a carboxyl group, an amino group, and other hydrophilic groups present in a top coat or the like remaining in the coating component. When used in combination with a modified polyolefin resin in this way, the water resistance of the coating can be improved by immobilizing the hydrophilic component or converting the hydrophilic functional group into a more hydrophobic functional group without impairing the properties of the polyolefin resin. It was found that the effect of improving the performance was improved.

Further, by adding a small amount of alcohol component to the modified polyolefin resin, the amount of surfactant and reactive surfactant required for stably dispersing the modified resin in water can be greatly reduced. It has been found that the composition after blending the isocyanate compound is also effective for stabilization.

The aqueous resin composition of the present invention has excellent adhesion to polyolefin, good storage stability, and good flexibility of the coating film. Moreover, a water-resistant coating film can be formed as compared with a conventional polyolefin-based aqueous resin composition using a surfactant. In addition, since it can be made aqueous without using any aromatic organic solvent, it is excellent in terms of safety and health and environmental pollution.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C09D 175/04 PHR C09D 175/04 PHR C09J 175/04 JFC C09J 175/04 JFC C09K 3/10 C09K 3/10 D // C08K 5/29 C08K 5/29

Claims (7)

(57) [Claims] 1. An aqueous resin composition comprising a modified polyolefin resin, a blocked isocyanate compound, and a surfactant. 2. An aqueous resin composition comprising a modified polyolefin resin, a blocked isocyanate compound, a surfactant and alcohols. 3. The modified polyolefin resin is obtained by graft copolymerizing (A) a polyolefin obtained by graft copolymerization of an unsaturated carboxylic acid or an acid anhydride, (B) a chlorinated polyolefin, and (C) a reactive monomer having radical polymerizability. 3. The aqueous resin composition according to claim 1, which is a modified polyolefin resin comprising one or more of the polymerized polyolefins. 4. The modified polyolefin resin is subjected to at least two types of modification by acid modification, chlorination modification and modification by a reactive monomer as shown in (A), (B) and (C) of claim 3. The aqueous resin composition according to any one of claims 1 to 3, which is a modified polyolefin resin obtained by the method. 5. A film-forming product comprising the aqueous resin composition according to claim 1. 6. A sealing agent comprising the aqueous resin composition according to claim 1. 7. An adhesive comprising the aqueous resin composition according to any one of claims 1 to 4.