JPH07188353A - Normal temperature-curable resin composition based on aqueous acryl-urethane complex and coating agent or ink using the same - Google Patents

Abstract

PURPOSE:To obtain a normal temperature-curable resin composition consisting of an aqueous polyurethane-vinyl polymer complex and a coating agent or ink using this resin composition. CONSTITUTION:This resin composition consists essentially of a polyurethane- vinyl polymer complex obtained by subjecting a polymerizable unsaturated monomer group to addition polymerization in the presence of an aqueous polyurethane. The aqueous polyurethane component is a polyurethane resin having CONHNH2 group at the ends and obtained by neutralizing a NCO-ended polyol- isocyanate compound composed essentially of (A) a polyhydroxy compound containing at least one carboxyl group and two or more hydroxyl groups, (B) a polyhydroxy compound having two or more hydroxyl groups and (C) a polymerizable unsaturated monomer having two or more isocyanate groups and extending the terminal chains by a polyfunctional hydrazide compound, and the vinyl polymer component consists of a polymerizable unsaturated monomer containing a ketone group or aldehyde group. The above resin composition is useful for aqueous coating agent or ink manufacturing.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a room temperature curable aqueous resin composition based on a polyurethane-vinyl polymer composite having a specific structure. More specifically, a room temperature crosslinkable aqueous resin composition that has excellent adhesion to plastic materials such as polyolefin and polyester, and provides a coating film having excellent durability such as water resistance, hot water resistance, solvent resistance, abrasion resistance, and weather resistance. And a coating agent or water-based ink using the same. The aqueous resin composition of the present invention can be widely used as a coating agent for plastics, leather, metals and the like, a binder for inks, and an adhesive. In particular, the aqueous resin composition of the present invention is suitable as a binder for aqueous ink for applications such as food packaging.

[0002]

2. Description of the Related Art As a water-based coating resin, an acrylic resin has been used in various applications due to its excellent weather resistance and toughness. Acrylic water-based resins can be easily produced in various forms from emulsion type to microemulsion type, and give a coating film excellent in weather resistance, gloss and alkali resistance, but flex resistance,
Insufficient in impact resistance and wear resistance,
It is extremely difficult to achieve good adhesion to both polyester and polyolefin substrates. On the other hand, a polyurethane-based water-based coating material is a material that is well balanced in terms of adhesion to both polyester and polyolefin substrates, but has the drawback of being expensive and having poor weather resistance. Further, an ionic group and / or an ionic group introduced for imparting water solubility or water dispersibility to the polyurethane resin and / or
Due to the hydrophilic group, the water resistance and hot water resistance of the coating film remain at a low level as compared with the solvent-based polyurethane resin coating material.

However, in recent years, the demand for coating agents has been diversified and highly functionalized due to the sophistication of the required quality for coating films, the diversification of coating base materials, the use for new applications, and the like. In addition to conventional weather resistance, there are increasing applications that require adhesion to various types of base materials (particularly polyester-based and polyolefin-based plastic base materials) and toughness and abrasion resistance of a film comparable to urethane resins. In order to meet such demands, it is difficult to achieve by the conventional single material approach. For this reason, various proposals have recently been made regarding mixing or compounding a plurality of materials having different characteristics. For example, as a method of compounding a vinyl polymer and a urethane resin, a vinyl monomer is added to a polyurethane aqueous emulsion, and the vinyl polymer is polymerized after being uniformly emulsified and dispersed. A method for producing an aqueous resin has been proposed (JP-A-5-132535). The coating film of the vinyl-polyurethane composite resin according to the present proposal is excellent in film strength and film elasticity, but at an insufficient level in water resistance and heat resistance.

As another measure for functionally binding both the aqueous polyurethane resin and the acrylic resin, the urethane prepolymer obtained by reacting diisocyanates with glycols containing carboxyl group-containing glycols is neutralized, and Aqueous coating agent obtained by polymerizing a radically polymerizable acrylic monomer containing a carbonyl group-containing monomer or an amide group-containing monomer in the presence of an aqueous polyurethane resin obtained by chain extension with a hydrazine derivative A composition has been proposed (JP-A-1-301762).
In this proposal, it is required to use a hydrazine derivative as a chain extender, and as the hydrazine derivative, hydrazine, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-
1,4-dihydrazine and the like are mentioned.

In this proposal, in order to retain the chemical structure of --NHNH _{2 at} the end of the aqueous polymer molecule obtained after chain extension of the isocyanate-terminated urethane prepolymer, the chain extender hydrazine derivative is necessarily NC.
There is no choice but to use a large excess amount with respect to the O group concentration. Therefore, the free unreacted hydrazine derivative is present in the aqueous coating composition finally obtained by the method of the present invention. Hydrazine is a highly toxic substance (permissible concentration 0.1 ppm, 0.13 mg / m ³ ), which is suspected of being carcinogenic to humans, shows strong alkalinity, invades skin, and causes other mucous membranes. It is said to give strong corrosion to the above (12093 product, Chemical Daily Co., Ltd. (issued January 22, 1993), p132). Therefore, there is concern that problems may occur when the coating resin based on this proposal is used in the field of paints and inks related to containers or packaging materials that may come into contact with products or foods that may come into contact with the human body. To be done.

[0006]

Under the circumstances, the present inventors have found that binders for cold-crosslinking water-based paints which give coating films having excellent adhesion to both polyester and polyolefin materials and excellent durability. As a result, it was decided to diligently study a method for obtaining a suitable aqueous resin.

[0007]

The present inventors have reached the present invention as a result of intensive studies to solve the above-mentioned problems. That is, the above-mentioned object and problem of the present invention are room temperature curing comprising a polyurethane-vinyl polymer composite obtained by addition-polymerizing a polymerizable unsaturated monomer group in the presence of a polyurethane containing a carboxyl group, and water. -Type water-based resin, the polyurethane component containing a carboxyl group (A) a polyhydroxy compound containing at least one carboxyl group and two or more hydroxyl groups,
(B) a polyhydroxy group compound having two or more hydroxyl groups, (C) an isocyanate compound having two or more isocyanate groups, (D) a hydroxy compound having a polymerizable unsaturated group, and A to D as essential components Is a polyurethane resin having a —CONHNH ₂ group at the end obtained by neutralizing the NCO-terminated polyol-isocyanate polyaddition reaction product and extending the chain with a polyfunctional hydrazide compound. Was achieved for the first time by an aqueous resin composition characterized by comprising a polymerizable unsaturated monomer mixture containing a polymerizable unsaturated monomer having a ketone group or an aldehyde group.

The aqueous polyurethane resin in the present invention is produced, for example, by the following method. That is, first, a diisocyanate compound, a diol compound, a diol compound containing a carboxyl group and a hydroxyl compound having a polymerizable unsaturated group are subjected to a urethane reaction in an organic solvent,
Prepare the prepolymer. As the diisocyanate compound used at this time, various known aromatic, aliphatic or alicyclic diisocyanates can be used. Specific examples of the diisocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, m-phenylene diisocyanate and xylylene diisocyanate. Aromatic diisocyanates such as 4,4'-diphenyldimethylmethane diisocyanate and 4,4'-dibenzyl isocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,4
And aliphatic or alicyclic diisocyanates such as dicyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and isophorone diisocyanate.

The diols include (a) polyethers such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; (b) ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentyl glycol, cyclohexane. Polyhydric alcohols such as dimethanol and maleic acid, succinic acid, glutaric acid, adipic acid,
Polyester obtained by dehydration condensation reaction with polyvalent carboxylic acid such as sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid or ring-opening polymerization reaction of cyclic ester such as caprolactone and pivalolactone, (c) polycarbonate, etc. Polydiol, (d) ethylene glycol, diethylene glycol,
Triethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, hydrogenated bisphenol A, bisphenol A ethylene oxide or propylene Examples thereof include oxide adducts and low-molecular glycols such as bisphenol S ethylene oxide. Examples of acid group-containing glycols that are water-solubility-imparting agents include diols containing a carboxyl group in the molecule such as 2,2-dimethylolpropionic acid, 2,2-dimethylollacric acid, and 2,2-dimethylolvaleric acid. Can be mentioned. Examples of the hydroxyl compound having a polymerizable unsaturated group include β-hydroxyethyl methacrylate (HEMA), β-hydroxyethyl acrylate, γ
-Hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, glycerin monoallyl ether and the like can be mentioned.

The above-mentioned diols may be used alone or in combination of several kinds. It is essential that the polyurethane polymer in the water-based resin of the present invention contains 5% by weight or more of the aromatic ring and / or the nucleus-substituted aromatic ring unit derived from the polyol component, based on the total weight of the polyurethane polymer. When the content of the aromatic ring derived from the polyol component and / or the substituted aromatic ring unit is less than 5% by weight, the heat resistance of the coating film obtained from the aqueous coating agent of the present invention and the polyester material (for example, PET film) Adhesion to is insufficient. Specific examples of the aromatic ring and / or nucleus-substituted aromatic ring unit include the followings, but are not particularly limited thereto.

[0011]

[Chemical 1]

[Chemical 2]

[Chemical 3]

[0012]

[Chemical 4]

[Chemical 5]

[Chemical 6]

In order to introduce these aromatic ring and / or nucleus-substituted aromatic ring units into the polyurethane polymer, diols or polyester diols as shown below are preferably used.

[Chemical 7]

[Chemical 8]

[Chemical 9]

[0014]

[Chemical 10]

[Chemical 11]

[Chemical 12]

[0015]

[Chemical 13]

[Chemical 14]

[Chemical 15]

Typical examples of the polyester diol include the following types, but are not limited to these types. (1) Copolyester (EG / N) consisting of ethylene glycol (EG), neopentyl glycol (NPG), terephthalic acid (TPA) and isophthalic acid (IPA)
PG = 50/50 (molar ratio), TPA / IPA = 50 /
50 (molar ratio), OH value = 5 to 50 mg-KOH / g) (2) Ethylene glycol, neopentyl glycol,
Copolyester consisting of terephthalic acid, isophthalic acid and sebacic acid (SA) (EG / NPG = 50/50)
(Molar ratio), TPA / IPA / SA = 45/45/10
(Molar ratio), OH value = 5 to 50 mg-KOH / g) (3) Copolyester (EG / Bis) consisting of ethylene glycol, bisphenol A ethylene oxide adduct (Bis-AEO), terephthalic acid and isophthalic acid
-AEO = 75/25 (molar ratio), TPA / IPA = 5
0/50 (molar ratio), OH value = 5 to 50 mg-KOH /
g) (4) ethylene glycol, neopentyl glycol,
Copolyester consisting of terephthalic acid and sebacic acid (EG / NPG = 60/40 (molar ratio), terephthalic acid / sebacic acid = 70/30 (molar ratio), OH value = 5-5
0 mg-KOH / g)

(5) Copolyester consisting of butanediol, terephthalic acid, isophthalic acid and sebacic acid (TPA / IPA / SA = 33/33/34 (molar ratio), OH value = 5 to 50 mg-KOH / g) (6) ethylene glycol, neopentyl glycol,
Copolyester oligomer composed of terephthalic acid and isophthalic acid (EG / NPG = 50/50 (molar ratio),
TPA / IPA = 50/50 (molar ratio), OH value = 15
~ 50 mg-KOH / g) to a diisocyanate compound (4,4'-methylenebisdiisocyanate, 2,4-
Urethane-modified polyester polyol obtained by reacting tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, etc.) under the condition that the equivalent relationship of the terminal groups is OH / NCO> 1 (7) ethylene glycol, neopentyl glycol,
Copolyester oligomer composed of terephthalic acid and isophthalic acid (EG / NPG = 50/50 (molar ratio),
TPA / IPA = 50/50 (molar ratio), OH value = 15
˜50 mg-KOH / g), dimethylolpropionic acid and isophorone diisocyanate were mixed at a terminal group concentration ratio (O
H / NCO = 1.5 to 2.0) and a urethane-modified polyester polyol having an acid value of 10 to 40 mg-KOH / g obtained by the reaction (8) ethylene glycol, neopentyl glycol,
Copolyester oligomer composed of terephthalic acid and isophthalic acid (EG / NPG = 50/50 (molar ratio),
TPA / IPA = 50/50 (molar ratio), OH value = 15
˜50 mg-KOH / g), glycerin monoallyl ether (Daicel Chemical Industries, Ltd.), and isophorone diisocyanate at the terminal group concentration ratio (OH / NCO = 1.5 to 2.0).
A urethane-modified polyester polyol having a double bond on the pendant obtained by reacting under the conditions of.

The polyester diol may contain modest levels of ionizable functional groups such as carboxyl groups and the aqueous coatings obtained according to the invention by using a backbone polymer containing such ionic groups. The dispersion stability of the resin composition is improved, and it effectively contributes to making the emulsion particles finer.

The organic solvent used for the urethanization is preferably one which is inert to the isocyanate group and miscible with water, such as acetone or methyl ethyl ketone (ME
K), ketones such as methyl isobutyl ketone and cyclohexanone, ethers such as tetrahydrofuran, dioxane and dimethoxyethane, esters such as ethyl acetate and butyl acetate, and amide solvents such as N-methylpyrrolidone (NMP) alone or as a mixture. Is a specific example. The NCO-terminated prepolymer obtained by the above method is neutralized with a neutralizing agent such as a tertiary amine, and then (1) the polyfunctional carboxylic acid polyhydrazide compound is used to block the terminal NCO group of the prepolymer, or (2) Condition of functional group concentration ratio (NCO terminal group concentration) / [(-CONHNH ₂ group concentration) + (-NH ₂ group concentration)]> 1 by using polyfunctional amine and / or polyfunctional carboxylic acid polyhydrazide NCO remaining after chain extension with
By capping the terminal group with a polyfunctional carboxylic acid polyhydrazide, it is converted into an aqueous polyurethane resin having a -CONHNH ₂ group at the terminal to obtain an aqueous polyurethane dispersion, which is used in the present invention.

As the neutralizing agent used in the present invention, ammonia, trimethylamine, triethylamine, tripropylamine, triethanolamine, monoethanolamine, N-methylmorpholine, morpholine, 2,2-
Dimethylmonoethanolamine, amines such as N, N-dimethylmonoethanolamine, sodium hydroxide,
Examples thereof include potassium hydroxide. As the chain extender used in the present invention, various known ones can be used. Examples thereof include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, 1,6-diaminocyclohexane, m-xylylenediamine, hydrogenated 4,4'-.
Examples thereof include diamines and polyamines such as diaminodiphenylmethane, hydrated hydrazine, hydrazine derivatives such as adipic acid dihydrazide, and isophthalic acid dihydrazide.

In the present invention, the terminal blocking agent is
Requires the use of polyfunctional carboxylic acid polyhydrazides
It is a condition. Polyfunctional carboxylic acid polyhydrazide is
Functional carboxylic acid R-(-COOH) _n(N = 2,3)
General formula R-(-CONHNH₂)_n(N =
2, 3).

Specific examples of polyfunctional carboxylic acid polyhydrazides include oxalic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide (ADH), sebacic acid dihydrazide, dodecanedioic acid dihydrazide, maleic acid dihydrazide and fumar. Acid dihydrazide, itaconic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 4,4 '
-Oxybisbenzenesulfonyl hydrazide, trimesic acid trihydrazide, 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (VDH),
Examples thereof include enocosanic diacid dihydrazide, 7,11-octadecadiene-1,18-dicarbohydrazide, polyacrylic acid hydrazide, and acrylamide-acrylic acid hydrazide copolymer. Among these, adipic acid dihydrazide, isophthalic acid dihydrazide and 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (VDH) are preferably used.

The polyhydric carboxylic acid polyhydrazide compound is
It is superior to hydrazine derivatives used in the prior art in terms of safety. The safety data of VDH, which is a typical substance among the polyhydric carboxylic acid polyhydrazides used in the present invention, is as follows (Ajinomoto Co., Inc. Amicure VDH technical data). (1) Acute oral toxicity LD ₅₀ 20 g / kg or more (mouse) (2) Primary skin irritation None (3) Eye mucosa primary irritation None In the present invention, the purpose of using a polyfunctional hydrazide derivative as a chain extender is To obtain aqueous urethane. For that purpose, with respect to NCO-terminated urethane prepolymer, the concentration ratio of the functional groups [-CONHNH _2] /
It is desirable to add the polyfunctional hydrazide derivative under the condition that [-NCO]> 1. Considering the molecular weight of the final aqueous urethane, this concentration ratio is preferably in the range of 1.2 to 1.8, and more preferably in the range of 1.3 to 1.8. The polyurethane resin containing a carboxyl group of the present invention is synthesized from a diisocyanate compound, a diol compound, a diol compound containing a carboxyl group and a hydroxyl compound containing a polymerizable unsaturated group,
When carrying out this synthesis reaction, a small amount of a trivalent or higher valent isocyanate compound and a hydroxyl compound may coexist as a copolymerization component to introduce a branched structure into the resulting aqueous polyurethane resin.

The molecular weight of the carboxyl group-containing polyurethane of the present invention is Mw (weight average molecular weight) = 3 in terms of polystyrene by gel permeation chromatography.
000 or more and Mw = 100,000 or less, more preferably Mw = 5,000 or more and Mw = 50,000 or less. When Mw is less than 3,000, the toughness and abrasion resistance of the coating film from the aqueous resin composition of the present invention are insufficient, which is not preferable. If Mw exceeds 100,000, the polymerization stability during vinyl polymerization is deteriorated, and the dispersion stability of the aqueous resin composition of the present invention is deteriorated, which is not preferable. The acid value of the polyurethane resin containing a carboxyl group of the present invention ranges from 5 mg-KOH / g to 200 mg-KOH / g.
It is preferably in the range of g, more preferably 10 to 100.
It is preferably in the range of mg-KOH / g. Acid value is 5mg
When it is less than -KOH / g, the dispersion stability of the aqueous coating agent of the present invention is deteriorated, which is not preferable. Acid value is 200m
When it exceeds g-KOH / g, the water resistance of the coating film obtained from the aqueous coating agent of the present invention is deteriorated, which is not preferable.

A typical example of the polymerizable unsaturated monomer which is polymerized in the presence of the polyurethane aqueous emulsion produced by the above-mentioned method is a vinyl-based monomer. Is methyl methacrylate (MMA), ethyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, nonyl methacrylate, lauryl methacrylate (LMA), stearyl methacrylate, and other methacrylate esters; methyl acrylate; Ethyl acrylate (EA), butyl acrylate,
Hexyl acrylate, 2-ethylhexyl acrylate,
Acrylic esters such as octyl acrylate; aromatic vinyl monomers such as styrene (ST), p-methylstyrene, α-methylstyrene, p-chlorostyrene, chloromethylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile. Unsaturated nitriles such as, butadiene, conjugated diolefins such as isoprene, divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, allyl methacrylate, diallyl phthalate, trimethylolpropane triacrylate, glycerin diallyl ether, Polyfunctional vinyl monomers such as polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, acrylamide, methacrylamide, n-methyl ester Lumpur methacrylamide such as amide monomers, beta-hydroxyethyl acrylate (HEM
A), hydroxy group-containing monomer such as β-hydroxyethyl methacrylate, amino group-containing polymer such as dimethylaminoethyl acrylate and diethylaminoethyl acrylate, glycidyl group-containing unit such as glycidyl acrylate and glycidyl methacrylate (GMA) And acid monomers such as acrylic acid, methacrylic acid, itaconic acid and p-vinylbenzoic acid, and vinyl monomers such as vinyl acetate, vinyl chloride and vinylidene chloride.

In order to obtain an aqueous resin having good coating physical properties, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate can be selected from the above vinyl monomers. Acrylic esters such as, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate,
It is preferable to select a methacrylic acid ester such as glycidyl methacrylate and a monomer mixture containing styrene as a main component. Examples of the polymerizable unsaturated monomer containing an aldehyde group or a ketone group include acrolein,
Diacetone acrylamide (DAAM), acetoacetoxyethyl methacrylate, p-formylstyrene, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, vinyl acetophenone, vinyl benzophenone, general formula

[Chemical 16] (Here, R ¹ is H or CH ₃ , R ² is H or an alkyl group having 1 to ³ carbon atoms, R ³ is an alkyl group having 1 to ³ carbon atoms, and R ⁴ is an alkyl group having 1 to ⁴ carbon atoms. Acrylic (or methacryl) oxypropenal represented by group), diacetone acrylate, acetonitrile acrylate, diacetone methacrylate, 2-hydroxypropyl acrylate acetyl acetate, butanediol-1,4-acrylate acetyl acetate, and the like.

Particularly preferred monomers thereof include diacetone acrylamide, acrolein and vinyl methyl ketone. Two or more kinds of these monomers having a ketone group may be contained in the graft chain. The amount of the aldehyde group- or ketone group-containing vinyl monomer used is
0.5-3 based on the total dry weight of the vinyl polymer of the present invention
It is 0% by weight, preferably 1 to 20% by weight. Radical polymerization is preferred as the method for polymerizing the vinyl monomer,
As the radical polymerization initiator, 2,2'-azobisisobutyronitrile, t-butyl hydroperoxide, 1,1'-azobis- (cyclohexane-1-carbonitrile), 2,2'-azobis- (2-amidinopropane) dihydrochloride, 2,2′-azobis- (2,4-dimethylvaleronitrile), hydrogen peroxide potassium persulfate,
2,2'-azobis- (2-amidinopropane) dihydrochloride, 4,4'-azobis-4-cyanovaleric acid, ammonium persulfate redox type initiator and the like can be mentioned. These are based on vinyl type monomers. It is preferably used in the range of 0.1 to 5 wt%.

In carrying out the present invention, a safe aqueous resin can be obtained without using a surfactant which is used when ordinary emulsion polymerization is carried out. However, a surfactant or a self-emulsifying vinyl monomer may be used in combination if necessary. The polyurethane-vinyl composite of the present invention is
It is derived by addition-polymerizing a polymerizable unsaturated monomer group in the presence of an aqueous polyurethane. And / or water-dispersible resin may coexist.

(1) Styrene / butyl acrylate / acrylic acid copolymer (acid value: 30 to 200 mg-KOH /
Water-soluble or water-dispersible resin such as g) (2) Graft copolymer having a polyurethane resin as a trunk polymer and an acrylic copolymer as a graft chain (acid value: 30 to 200 mg-KOH / g) (3) Amine salt of hydrolyzed styrene / maleic anhydride alternating copolymer (4) Graft-type aqueous resin based on polyurethane and acrylic polymer (5) Water-soluble acrylic resin as shell material, hydrophobic acrylic resin as core component (6) Soap-free acrylic polymer emulsion obtained by using self-emulsifying monomer (7) Acrylic emulsion obtained by emulsion polymerization (8) Water-soluble and / or water-dispersible Polyester resin (9) Water-soluble cellulosic polymer

In forming a coating film from the aqueous resin composition of the present invention, a high molecular reaction (aldehyde group or aldehyde group or IPN (interpenetrating network) by formation of imino group by reaction of ketone group and hydrazide group
Formation occurs to form a tough film, but if necessary, a compound containing a low molecular weight or high molecular weight -CONHNH ₂ group may be added to the aqueous resin composition of the present invention within the range of the following equivalent relationship. May be added in. This-CON
Specific examples of the compound containing HNH ₂ include adipic acid hydrazide, isophthalic acid hydrazide, and 1,3-bis (hydrazinocarboethyl)-, which are listed as examples of polyhydric carboxylic acid polyhydrazide used for the end-capping agent. Examples thereof include low-molecular compounds such as 5-isopropylhydantoin and polymer compounds such as polyacrylic acid hydrazide and acrylamide-acrylic acid hydrazide copolymer.

Although the water-based resin composition of the present invention uses water as a solvent, an organic solvent miscible with water may be added if necessary. Concentration (A) of aldehyde groups or ketone groups contained in the vinyl polymer of the present invention
-CON at the end of urethane resin containing a carboxyl group
Concentration of HNH ₂ groups and low or high molecular weight -CON
The equivalent relationship with the sum of the concentrations of the HNH ₂ group-containing compound (B) is preferably in the range of 0.5 ≦ A / B ≦ 2.0, more preferably 2/3 ≦ A /
It is desirable that B ≦ 1.5.

Regarding the composition ratio of the aqueous polyurethane and the vinyl polymer, the dry weight C of the aqueous polyurethane resin and the dry weight D of the vinyl polymer satisfy the relational expression of 0.1≤C / (C + D) ≤0.9. Preferably. When C / (C + D) is 0.1 terminal, it is difficult to obtain an aqueous resin having good dispersion stability, which is not preferable. When C / (C + D) exceeds 0.9, the solvent resistance, weather resistance, gloss and the like of the film formed from the aqueous resin of the present invention are unfavorable.

The aqueous resin composition of the present invention is mainly composed of a polyurethane-vinyl polymer composite having a specific structure based on a urethane polymer containing a carboxyl group and water. Water-soluble resins and water-dispersible resins as exemplified below may be added in equal amounts or less in dry weight ratio. (1) Methyl methacrylate / butyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid copolymer (weight ratio of each monomer is 60: 22.2: 10: 7.8) (2) Styrene / maleic anhydride Hydrolyzate of alternating copolymer

(3) Styrene / maleic anhydride alternating copolymer and styrene / maleic acid half ester copolymer derived from monohydric alcohol (4) Water-soluble acrylic resin as shell material, hydrophobic acrylic resin as core Core / shell type emulsion as a component (5) Soap-free acrylic polymer emulsion obtained by using self-emulsifying monomer (6) Acrylic emulsion obtained by emulsion polymerization (7) Water-soluble and / or water-dispersion -Resistant Polyester (and / or Alkyd) Resin (8) Water-soluble Cellulose Polymer

[0035]

EXAMPLES The present invention will now be described in more detail with reference to examples. The physical properties in the examples were evaluated as follows. 1. Adhesiveness The aqueous coating agent of the present invention is treated with a corona-treated biaxially oriented polyethylene terephthalate film (Toray Industries, Inc. “Lumirror” P60, 12μ) or a corona-treated biaxially oriented polypropylene film (Toray Industries, Inc. “Trefan” 254).
5, 20μ) and the bar coater No. 5 was applied, and after being dried constantly for 24 hours, a cellotape peeling test was performed. The coating conditions were set so that the coating thickness after drying was in the range of 3 to 5 µ. Based on the area ratio of the remaining portion of the coating film after the cellotape peeling test, three grades of ◯ (100% remaining), Δ (70% or more remaining), × (50% or more peeling) were determined.

2. Hot water resistance The coated product prepared by the above method was immersed in boiling water for 10 minutes and taken out, and the following three grades were judged from the change in appearance. ○: No big difference from the state before the boiling water test. Δ: The coating film is slightly whitened. There are slight wrinkles on the coating. X: The coating film is whitened. Large wrinkles occur on the coating film. The coating film falls off from the base film. 3. Solvent resistance The coated product prepared by the method of paragraph 1 was rubbed with absorbent cotton impregnated with ethyl alcohol, and the number of strokes until the base film was exposed was judged in three stages. O: Over 20 times. Δ: 5 to 20 times. ×: less than 5 times.

Example I 1 (Production of hydrazide-terminated aqueous urethane) Polypropylene glycol (Molecular weight 2000) 200 g Isophoronidiisocyanate 88.8 g Dimethylolpropionic acid 30 g Ethyl acetate 60 g A 2-liter four-necked flask equipped with a stirrer was charged, and the temperature was raised to 90 ° C. under stirring in a nitrogen atmosphere, and a urethanization reaction was carried out at this temperature for 1 hour. Then ethyl acetate 9
0 g was added dropwise over 30 minutes, and the reaction was continued at 90 ° C. for 1 hour. Then, it cooled to 40 degreeC and obtained the NCO terminal prepolymer. Then, 20 g of triethylamine was added to this prepolymer to neutralize it, and then ion-exchanged water 600
g was added. Next, 13.5 g of adipic acid dihydrazide was added to the reaction system, and stirring was continued at 50 ° C. for 1 hour, and then ethyl acetate was distilled off under reduced pressure to obtain hydrazide-terminated aqueous urethane A. The solid content of this aqueous resin is 35.1.
%, The molecular weight measured by GPC is _Mu = 14,000.
M _w = 33,000.

In the same manner, aqueous urethanes B, C and D were produced using the raw materials shown in Table 1 instead of polypropylene glycol and the like.

[Table 1]

The abbreviations in the Tables indicate the following compounds, respectively. (A) PPG: polypropylene glycol (molecular weight 20
00) Manufacturer name: Takeda Pharmaceutical Co., Ltd. (b) PCL: Polycaprolactone (molecular weight 2000) Manufacturer name: Daicel Chemical Co., Ltd. (c) PE / NT / I: Ethylene glycol (E),
Neopentyl glycol (N), terephthalic acid (T),
Copolymerized polyester resin composed of isophthalic acid (I) (copolymerization composition: E / N · T / I = 50/50 · 50/5
0 (molar ratio), molecular weight 1800) Manufacturer name: Unitika Ltd. DMPA: Dimethylolpropionic acid IPDI: Isophone diisocyanate (manufactured by Huls) TEA: Triethylamine EAC: Ethyl acetate NMP: N-Methylpyrrolidone ADH: Adipic acid dihydrazide VDH: dihydrazide compound (trade name of Ajinomoto Co., Inc.
Amicure VDH)

2. (Production of Polyurethane-Vinyl Polymer Composite) Aqueous Polyurethane Aqueous Dispersion Liquid B, 270 synthesized in the above item 1.
and 150 g of ion-exchanged water were charged into a 2-liter 4-necked flask equipped with a reflux condenser, a nitrogen introducing tube, a thermometer, a dropping funnel and a stirrer, and the temperature was raised from room temperature to 80 ° C. for 30 minutes. . From the dropping funnel, a mixture of ethyl acrylate 80 g styrene 15 g diacetone acrylamide 5 g hydrogen peroxide 2 g and distilled water 20 g was added dropwise over 4 hours, and stirring was continued for 1 hour after the addition was completed. Then add 1 g of hydrogen peroxide,
Stirring was continued for 2 hours at 0 ° C. to complete the graft polymerization reaction.

[Table 2]

[0041] Example II, according to the composition shown in Table 2 III and Comparative Example I~IV Example I a similar manner was prepared Example II, the aqueous resin III and Comparative Example I-IV.

Comparative Example V 150 g of isopropyl alcohol was charged into a 2-liter 4-necked flask equipped with a reflux condenser, a nitrogen introducing tube, a dropping funnel, and a stirrer, and the temperature was raised to 85 ° C. From the dropping funnel, 60 g of lauryl methacrylate, 120 g of butyl acrylate, 75 g of methyl methacrylate, 15
A mixture of g of diacetone acrylamide, 30 g of methacrylic acid and 3 g of azobisisobutyronitrile was added dropwise over 3 hours, and after completion of the dropwise addition, stirring was continued at 85 ° C. for 2 hours for aging. The polymer was cooled to 35 ° C., 21 g of 28% ammonia water was added and neutralized, and then 550 g of distilled water in which 13 g of VDH was dissolved was added to give a solid content of 30% and a viscosity of 7.5 poise. A water soluble resin was prepared.

Comparative Example VI 100 g of the water-soluble resin obtained in Comparative Example V and 100 g of the aqueous urethane resin of B were blended to prepare an acrylic-urethane blend type aqueous resin. The above-mentioned aqueous resins of Examples I to III and Comparative Examples I to VI were evaluated by the method described above, and the results are shown in Table 3.

[Table 3]

Example IV 100 g of acrylic obtained by the method of Example I
Urethane composite emulsion, titanium oxide R-830 (manufactured by Ishihara Sangyo Co., Ltd.) 163 g, isopropyl alcohol 1
A mill base of 8 g and ion-exchanged water 15 g was blended, and the number of revolutions was 1600 with a batch type sand grinder.
Millbase 10 after 45 minutes dispersion under rpm conditions
45 parts by weight of the above acrylic-urethane composite emulsion, 7 parts by weight of isopropyl alcohol,
5 parts by weight of ion-exchanged water was added for red down. The white ink thus obtained was filtered through a 400-mesh stainless wire gauze, and then biaxially oriented polypropylene was obtained using a monochromatic printing station type gravure printing suitability tester (manufactured by Kumagai Riki Kogyo Co., Ltd.). Film (Toray Co., Ltd. “Trefan” 2445 20μ thick) and biaxially oriented polyester film (Toray Co., Ltd., “Lumirror” P60, 12μ
Printing). Printing conditions are printing speed 60m / m
in, printing pressure was 20 kg / cm. When the adhesiveness of the ink was examined by a cellophane tape peeling test, no peeling of the ink was observed in both types of films.

[0045]

As is apparent from the examples and comparative examples, the aqueous resin composition of the present invention, and particularly the aqueous coating agent and ink using the same, have both polyester and polyolefin base materials having remarkably different surface polarities. It is clear that the coating film obtained from this composition has excellent adhesion to water and the water resistance and solvent resistance are comparable to those of conventional solvent-based paints. Therefore, the composition of the present invention is a plastic molded article,
It can be widely used in the field of water-based coating agents for films and water-based inks, and also contributes to the preservation of the global environment.

Claims (6)

[Claims] 1. A room-temperature curable aqueous resin composition comprising a polyurethane-vinyl polymer composite obtained by addition-polymerizing a polymerizable unsaturated monomer group in the presence of a polyurethane containing a carboxyl group, and water as a main component. In, the polyurethane component containing a carboxyl group is (A) at least 1
Polyhydroxy compound containing one carboxyl group and two or more hydroxyl groups, (B) polyhydroxy compound having two or more hydroxyl groups, (C) isocyanate compound having two or more isocyanate groups,
(D) A hydroxy compound having a polymerizable unsaturated group, which is composed of A to D as an essential component, neutralizes the NCO-terminated polyol-isocyanate polyaddition reaction product, and chain-extends it with a polyfunctional hydrazide compound. The obtained polyurethane resin having a -CONHNH ₂ group at the terminal, wherein the vinyl polymer component is composed of a polymerizable unsaturated monomer mixture containing a polymerizable unsaturated monomer having a ketone group or an aldehyde group. And an aqueous resin composition. 2. The aqueous solution according to claim 1, wherein the polyurethane resin contains an aromatic ring and / or a nucleus-substituted aromatic ring unit derived from a polyol component in an amount of 5% by weight or more based on the total weight% of the polyurethane resin. Resin composition. 3. The aqueous resin composition according to claim 1, wherein the polyfunctional hydrazide compound is a dibasic acid dihydrazide. 4. The aqueous resin composition according to claim 1, wherein the polymerizable unsaturated monomer containing a ketone group is diacetone acrylamide. 5. An aqueous coating agent comprising the resin composition according to claim 1, 2 or 3. 6. A water-based ink comprising the resin composition according to claim 1.