JP3191978B2 - 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 a novel aqueous resin composition, and more particularly, it cures in a short time even at room temperature and has excellent mechanical strength, water resistance, solvent resistance, heat resistance and durability. The present invention relates to an aqueous resin composition which forms a film having various properties such as adhesion to a substrate and can be used in the fields of paints, surface treatment agents, coating agents, adhesives, sealing agents and the like.

[0002]

2. Description of the Related Art Since water-soluble, water-dilutable or water-dispersible acrylic resins, polyester resins, polyurethane resins and polyolefin resins are water-based, there is no danger of fire, working environment and contamination, and their coatings are not affected. Is characterized by having excellent mechanical strength, flexibility and solvent resistance,
It is widely used as a resin component such as paints, surface treatment agents, coating agents, adhesives, and sealing agents.However, in order to make it water-soluble, water-dilutable or water-dispersible, it must contain a large amount of hydrophilic groups. However, there were problems in water resistance, durability and the like.

[0003] In recent years, attempts have been made to improve various properties of a film by blending an aminoplast resin (for example, a water-soluble melamine resin), an epoxy resin, an aziridine-based compound, etc. as a curing agent for solving such a drawback ( JP
JP-A-47-27241, JP-A-54-41940, JP-A-55-41940
164244). JP-A-2-99537 and Japanese Patent Publication No.
JP-A-63-48884 discloses a curable composition in which a latex containing a carboxyl group is crosslinked with a latex containing a 2-oxazoline group.

[0004]

When a melamine resin, an epoxy resin, or an aziridine compound is used as a curing agent, since the curing agent is a low molecular weight compound, water resistance, adhesion and durability when formed into a film are obtained. Had a problem. Further, when a latex containing an oxazoline group is used, the efficiency of crosslinking with a reactive group is low because of the particulate form, and there are problems in curing speed, mechanical strength, water resistance and solvent resistance.

This invention cures in a short time even at room temperature and has excellent mechanical strength, water resistance, solvent resistance, heat resistance,
An object is to provide an aqueous resin composition capable of forming a film having various properties such as durability and adhesion to a substrate.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a water-soluble, water-dilutable or water-dispersible polymer (A) as a main component, and the polymer (A) At least a part of the polymer (A1) has a functional group capable of reacting with a 2-oxazoline group, and the water-soluble polymer (B) having a 2-oxazoline group is a polymer (A1)
Of the polymer (B)
The ratio is 1 to 5 with respect to 100 parts by weight of the polymer (A1).
0 parts by weight of an aqueous resin composition is provided.

The 2-oxazoline group has the following general formula (I)
Is a monovalent organic group represented by

[0008]

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Wherein R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, halogen, alkyl, aralkyl, phenyl or substituted phenyl. The polymer (A) used in the present invention is a water-soluble, water-dilutable or water-dispersible polymer. Part or all of the polymer (A) is a polymer (A1) having a functional group capable of reacting with a 2-oxazoline group, and the remainder of the polymer (A) is a polymer (A2) having no functional group. is there. The polymer (A1) has a solid content equivalent to 33 to 100% by weight of the entire polymer (A).
A range of 100% by weight is preferred. When the proportion of the polymer (A1) is less than 33% by weight, the performance may not be improved while utilizing the characteristics of the polymer (A1).

The polymer (A1) used in the present invention includes a water-soluble, water-dilutable or water-dispersible acrylic resin, polyester resin, polyurethane resin and polyolefin resin having a functional group capable of reacting with a 2-oxazoline group. And the like. Any one or more polymers selected from the group consisting of these can be used without particular limitation.

The functional group capable of reacting with the oxazoline group contained in the polymer (A1) includes, for example, a carboxyl group and a salt thereof, a carboxylic anhydride group, a mercapto group and the like. You can do it,
A carboxyl group and a carboxylic anhydride group are particularly preferred from the viewpoint of reactivity with an oxazoline group. The amount of the functional group is not particularly limited and may be appropriately selected, but the molecular weight per equivalent of the functional group is 100 to 20,000, preferably 500 to 1
It is preferable to contain a functional group at a ratio of 10,000. If the functional group is too large, the cured film becomes hard and brittle, and the water resistance and the adhesion to the substrate tend to be impaired. Conversely, if the functional group is too small, the degree of curing is insufficient, such as durability and water resistance. Tends to be impaired.

In the present invention, known polymers (A1) can be widely used. For example, Ack Reset 19E, Ack Reset 210E, Ack Reset 260
E, Acryset 288E, Arolon 453 (all manufactured by Nippon Shokubai Co., Ltd.) and other water-dispersible or water-soluble acrylic resins;
-40 (all manufactured by Nippon Soflan Processing Co., Ltd.), Hydran HW-110, Hydran HW-131, Hydran HW-135, Hydran HW-320, Bondic 72070 (all manufactured by Dainippon Ink and Chemicals, Inc.), Poise Water dispersible polyurethane resins such as 710, Poise 720 (all manufactured by Kao Corporation), Merci 525, Merci 585, Merci 414, Merci 455 (all manufactured by Toyo Polymer Co., Ltd.); Vironal MD-1200, Vironal MD-1400 Water-dispersible polyester resins such as Vylonal MD-1930 (all manufactured by Toyobo Co., Ltd.), WD3652, and WJL6342 (all manufactured by Eastman Chemical Company);
Water solubility such as Isoban-10, Isoban-06, Isoban-04 (all manufactured by Kuraray Isoprene Chemical Co., Ltd.), Primacol 5981, Primacol 5983, Primacol 5990, Primacol 5991 (all manufactured by Dow Chemical Company) And a water-dilutable or water-dispersible polyolefin-based resin.

In the present invention, if necessary, a water-soluble, water-dilutable or water-dispersible polymer (A2) having no functional group capable of reacting with a 2-oxazoline group is used. By using the polymer (A2), the adhesion to the substrate, the coating property, the pigment miscibility, and the like may be improved. As the polymer (A2) to be used, a known aqueous latex or the like can be widely used. Specific examples of the aqueous latex include an acrylic aqueous dispersion, a vinyl acetate aqueous dispersion, and styrene-
Butadiene-based aqueous dispersion, natural rubber latex and the like can be mentioned. Polymers such as the above aqueous tex (A
When a functional group capable of reacting with a 2-oxazoline group (for example, a functional group such as a carboxyl group or a mercapto group) is introduced into 2), it can be used as a polymer (A1).

The water-soluble polymer (B) used in the present invention is obtained by polymerizing an addition-polymerizable oxazoline (a) and, if necessary, at least one other monomer (b). is there. In the present invention, the addition-polymerizable oxazoline (a) is represented by the following general formula (II).

[0015]

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Wherein R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, halogen, alkyl, aralkyl, phenyl or substituted phenyl, and R ⁵ is a noncyclic ring having an addition-polymerizable unsaturated bond. Organic group. As a specific example,
2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-
Oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and one selected from these groups. Alternatively, a mixture of two or more can be used. Among them, 2-isopropenyl-2-oxazoline is preferred because it is easily available industrially.

The amount of the addition-polymerizable oxazoline (a) is not particularly limited, but is preferably 5% by weight or more in the monomer mixture used for obtaining the polymer (B). If the amount is less than 5% by weight, the degree of curing is insufficient, and durability and water resistance tend to be impaired. In the present invention, the other monomer (b) is not particularly limited as long as it is a monomer that does not react with the oxazoline group and is copolymerizable with the addition-polymerizable oxazoline (a).
Methyl acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-aminoethyl (meth) acrylate and the like (Meth) acrylic esters such as salts
S; (meth) acrylate unsaturated nitriles such as Le carbonitrile;
Unsaturated amides such as (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; methyl vinyl ether, ethyl vinyl ether Vinyl ethers; α-olefins such as ethylene and propylene; halogen-containing α, such as vinyl chloride, vinylidene chloride, and vinyl fluoride.
β-unsaturated monomers; styrene, α-methylstyrene,
Examples thereof include α, β-unsaturated aromatic monomers such as sodium styrenesulfonate, and one or a mixture of two or more thereof can be used.

The water-soluble polymer (B) is prepared by adding an addition-polymerizable oxazoline (a) and, if necessary, at least one other monomer (b) to a solution in an aqueous medium by a conventionally known polymerization method. It can be produced by performing polymerization. The aqueous medium that can be used is not particularly limited as long as it can be mixed with water. For example, water; or water and methanol, ethanol, propanol, isopropanol, butanol,
A mixed solution of tertiary butanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol, acetone, methyl ethyl ketone and the like can be mentioned.

In order to impart water solubility to the polymer (B), the proportion of the hydrophilic monomer in the monomer mixture must be 50% by weight.
Or more, preferably 70% by weight or more. The hydrophilic monomer means 2-hydroxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, (meth) in addition-polymerizable oxazoline (a) and other monomers (b). 2-aminoethyl acrylate and its
Salt, ( meth) acrylamide, N-methylol (meth)
Acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, (meth) acrylonitrile, sodium styrenesulfonate and the like can be mentioned.

[0020] in the present invention, blending ratio of the polymer (A1) and a water-soluble polymer (B), the polymer (A1) 10
In the range of 1 to 50 parts by weight of the polymer (B) with respect to 0 parts by weight.
There, the range favorable preferable 1 to 20 parts by weight. If the amount is less than 1 part by weight, the degree of curing is insufficient, and durability and water resistance are impaired. If the amount is more than 50 parts by weight, adhesion to a substrate tends to be impaired.

The composition of the present invention may contain, if necessary, a solvent, a plasticizer, an inorganic or organic filler, a coloring pigment, a dye, a thickener, a dispersant, a wetting agent as long as the object of the present invention is not impaired. It is also possible to add a defoaming agent, a preservative / antifungal agent, a rust inhibitor and the like. In producing the composition of the present invention, there is no particular limitation, and means commonly used by those skilled in the art can be widely applied. For example, an aqueous solution, a dilute solution or a dispersion of the polymer (A) is added to a water-soluble polymer. What is necessary is just to add and mix the coalescence (B) and other additives as needed. And when used for paints, surface treatment agents, coating agents, adhesives, sealing agents, roll coaters, sprays,
What is necessary is just to apply to a base material by a method commonly used by those skilled in the art, such as dipping and brushing. Curing can be carried out at room temperature for 1 day to 2 weeks, but if necessary, by heating at 120 ° C. for about 30 minutes.

[0022]

In the aqueous resin composition of the present invention, a specific polymer (A1) having a functional group capable of reacting with an oxazoline group reacts with a polymer (B) having an oxazoline group to form a crosslinked structure. Since it contains the water-based polymer (A) and the water-soluble polymer (B), it has good compatibility with various main ingredients, and is hardened densely even at room temperature. No equipment required. The composition is cured and has excellent mechanical strength, water resistance, solvent resistance, heat resistance,
Form a film having various properties such as durability and adhesion to a substrate. Therefore, the composition can be suitably used in the fields of paints, surface treatment agents, coating agents, adhesives, sealing agents and the like.

[0023]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.
In the following, “%” indicates “% by weight” and “parts” indicates “parts by weight” unless otherwise specified. -Production Example 1 (Production Example of Polymer (B))-In a flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube and a thermometer, 1350 parts of deionized water, 5 parts of sodium persulfate,
120 parts of 2-isopropenyl-2-oxazoline and 30 parts of ethyl acrylate were charged and heated to 50 ° C. while gently flowing nitrogen gas. Set the temperature in the flask to 50
After maintaining the temperature at ± 1 ° C., stirring was continued for 10 hours to complete the reaction, followed by cooling to obtain an oxazoline group-containing polymer aqueous solution (1) having a nonvolatile content of 10.2%. The number average molecular weight of this polymer was about 20,000.

Production Example 2 (Production Example of Polymer (B)) In a flask similar to Production Example 1, 1350 parts of deionized water,
5 parts of sodium persulfate and 150 parts of 2-isopropenyl-2-oxazoline were charged and heated to 50 ° C. while gently flowing nitrogen gas. The temperature in the flask was maintained at 50 ± 1 ° C., and stirring was continued for 10 hours to complete the reaction. After cooling, an aqueous solution of an oxazoline group-containing polymer (2) having a nonvolatile content of 10.2% was obtained. The number average molecular weight of this polymer was about 20,000.

Production Example 3 (Comparative Polymer Production Example) A flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer and a dropping funnel was charged with 782.4 parts of deionized water and Hytenol N. -08 (Daiichi Kogyo Seiyaku Co., Ltd., polyoxyethylene nonyl phenyl ether sulfate ammonium salt) 128 parts of a 15% aqueous solution is charged, the pH is adjusted to 9.0 with an appropriate amount of 28% aqueous ammonia, and 70 parts of nitrogen are supplied while gently flowing nitrogen gas. Heated to ° C. 64 parts of a 5% aqueous solution of potassium persulfate was poured into the mixture, and 288 parts of butyl acrylate, 288 parts of styrene and
A monomer mixture consisting of 64 parts of isopropenyl-2-oxazoline was added dropwise over 3 hours. During the reaction, nitrogen gas was continuously blown, and the temperature in the flask was kept at 70 ± 1 ° C. After maintaining the same temperature for 2 hours after the completion of the dropwise addition, the internal temperature was raised to 80 ° C., and stirring was continued for 1 hour to complete the reaction. Thereafter, the mixture was cooled to obtain an oxazoline group-containing polymer aqueous dispersion (3) having a nonvolatile content of 39.8% and a pH of 8.0.

Examples 1 to 4 and Comparative Examples 1 to 5 Aqueous dispersions were prepared according to the formulations shown in Table 1.
After casting on a plate made of tetrafluoroethylene resin (trade name “Teflon” manufactured by DuPont) at 5 ° C. and 75 ± 3% RH, the film was dried all day and night to produce a film having a thickness of about 0.3 mm. . The obtained film was allowed to stand under the same conditions for 7 days, then used as a test piece, and subjected to the following tests. 1) Solvent resistance Immerse the test piece in acetone at room temperature for 72 hours,
The swelling rate and the elution rate were calculated according to the following equations.

Swelling ratio = ((length after immersion−length before immersion) /
Length before immersion) x 100 (%) Dissolution rate = ((weight before immersion-weight after immersion and drying) / weight before immersion) x 100 (%) 2) Film strength Using an Instron tensile tester, It was measured at a tensile speed of 10 cm / min. 3) Boiling water resistance The film appearance after immersion in boiling water for 4 hours was observed.

The water-dispersible polyester resin, water-soluble melamine compound, epoxy resin and aziridine compound in Table 1 are as follows.・ Water-dispersible polyester resin (containing carboxyl group) Vironal MD-1930 (manufactured by Toyobo Co., Ltd.) ・ Water-soluble melamine compound (containing N-methylol group) Sumitex Resin M-3 (manufactured by Sumitomo Chemical Co., Ltd.) ・ Epoxy Resin (containing epoxy group) Epicron 85-75W (manufactured by Dainippon Ink and Chemicals, Inc.) Aziridine compound (containing aziridine group) Chemitite DZ-22E (manufactured by Nippon Shokubai Co., Ltd.)

[0029]

[Table 1]

Examples 5 to 8 and Comparative Examples 6 to 9 Aqueous dispersions were prepared according to the formulations shown in Table 2. Using these, a polyolefin sheet for building materials (corona discharge treated product, 0.08 mm thickness) and a type I plywood (2.7 mm thickness) were bonded under the following bonding conditions. [Laminating conditions] Coating amount: 12 g / 30 cm ² Coating method: Manual roll Pressing condition: Pressing at 0.5 kg / cm ² for 3 hours (room temperature) Curing: Room temperature for 5 days Normal strength and water resistance of the obtained laminated plywood , Heat resistance and boiling water resistance were measured according to the following methods. Peeling strength was measured using an Instron tensile tester at a tensile speed of 30.
It was measured in cm / min.

Normal strength: 18 at 20 ° C. and 60% RH
The 0 degree peeling strength was measured. Water resistance strength: Left in water at 20 ° C. for 20 hours, and the 180 ° peeling strength in a wet state was measured. Heat resistance: 180-degree peeling strength immediately after standing at 60 ° C. for 1 hour was measured.

Boiling water resistance: 20 minutes after immersion in boiling water for 4 hours
The sample was left in water at 30 ° C. for 30 minutes, and the 180-degree peeling strength in a wet state was measured. The water-soluble polyolefin-based resin, water-dispersible polyurethane resin, and vinyl acetate-based aqueous dispersion in Table 2 are as follows. An aqueous solution obtained by dispersing 100 parts of a water-soluble polyolefin-based resin (containing a carboxyl group) Isovan-06 (manufactured by Kuraray Isoprene Chemical Co., Ltd.) in 247 parts of water and then adding 53 parts of 25% ammonia water. Polyurethane resin (containing carboxyl group) Hydran HW311 (manufactured by Dainippon Ink and Chemicals, Inc.)-Vinyl acetate aqueous dispersion (does not contain a functional group that can react with 2-oxazoline group) Bond CV270L (manufactured by Konishi Corporation)

[0033]

[Table 2]

-Examples 9 to 12 and Comparative Examples 10 to 17-The aqueous dispersions were prepared according to the formulations shown in Table 3 and were adjusted to 20 ± 0.
After casting on a plate made of tetrafluoroethylene resin (trade name “Teflon” manufactured by DuPont) under the conditions of 5 ° C. and 75 ± 3% RH, the film is dried all day and night to produce a film having a thickness of about 0.3 mm. did. The following test was carried out by using the obtained film as a test piece while leaving it under the same conditions for 7 days, and curing it at 120 ° C. for 5 minutes. 4) Solvent resistance The test piece was immersed in xylene at room temperature for 24 hours,
The swelling rate and the elution rate were calculated according to the following equations.

Swelling ratio = ((weight after immersion−weight before immersion) /
Length before immersion) x 100 (%) Dissolution rate = ((weight before immersion-weight after immersion drying) / weight before immersion) x 100 (%) The water-soluble acrylic resin, acrylic emulsion,
The water-soluble melamine compound, epoxy resin, and aziridine compound are as follows.・ Water-soluble acrylic resin (containing carboxyl group) Arolone 453 (manufactured by Nippon Shokubai Co., Ltd.) ・ Acrylic emulsion (containing carboxyl group) Acryset 210E (manufactured by Nippon Shokubai Co., Ltd.) ・ Water-soluble melamine compound (containing N-methylol group) Sumi Tex resin M-3 (manufactured by Sumitomo Chemical Co., Ltd.)-Epoxy resin (containing epoxy group) Epicron 85-75W (manufactured by Dainippon Ink and Chemicals, Inc.)-Aziridine-based compound (containing aziridine group) Chemitite DZ-22E (stock) Nippon Shokubai Co., Ltd.)

[0036]

[Table 3]

As is clear from Tables 1, 2 and 3,
The aqueous resin composition of the present invention cures in a short time even at room temperature, and has excellent mechanical strength, water resistance, solvent resistance, heat resistance, durability, and various properties such as adhesion to a substrate. Can be formed.

[0038]

The aqueous resin composition of the present invention cures in a short time even at room temperature and has excellent mechanical strength, water resistance, solvent resistance, heat resistance, durability, adhesion to a substrate, etc. It can form a film having various performances. Therefore, the aqueous resin composition of the present invention can be effectively used for various applications such as paints, surface treatment agents, coating agents, adhesives, and sealing agents.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-99537 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08G 73 / 00 C08G 81/00

Claims (2)

(57) [Claims] 1. A functional group containing a water-soluble, water-dilutable or water-dispersible polymer (A) as a main component, and at least a part of the polymer (A) capable of reacting with a 2-oxazoline group. (A1), which contains a water-soluble polymer (B) having a 2-oxazoline group as a crosslinking agent for the polymer (A1), and a blending ratio of the polymer (B)
Is 1 to 50 parts by weight based on 100 parts by weight of the polymer (A1).
Aqueous resin composition in parts by weight . 2. The aqueous resin composition according to claim 1, wherein the polymer (A1) is at least one selected from an acrylic resin, a polyester resin, a polyurethane resin and a polyolefin resin.