JP2002105111A - Water-based resin emulsion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based resin emulsion composition of one-pack cold-curing type, excellent in water resistance and solvent resistance. SOLUTION: This water-based resin emulsion composition comprises (A) a water-based resin emulsion which is obtained by copolymerizing (a) a polymerizable double bond-containing monomer having a carbonyl group in its molecule and (b) a polyfunctional monomer having two or more polymerizable double bonds with a self-emulsifiable polyurethane resin as a seed polymer, and (B) an organic polyfunctional hydrazide compound containing at least two hydrazide groups in its molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin emulsion composition having excellent water resistance and solvent resistance, and more particularly to a one-part, room temperature-curable aqueous resin emulsion composition.

[0002]

2. Description of the Related Art Conventionally, in the field of various coating agents such as adhesives, paints and printing inks, solvent-based coating agents using an organic solvent have been the mainstream. The conversion from solvent-based coating agents to water-based coating agents has been considered for various problems such as pollution, occupational safety and health such as organic solvent poisoning, danger of inflammation explosion, etc., and for the purpose of saving energy and resources. , Some are actually in progress.

[0003] Among the aqueous coating agents, a one-part cold curing type is preferable from the viewpoint of workability. However, from the viewpoint of the performance of the coating agent such as water resistance and solvent resistance, the development of a two-part type aqueous coating agent is desirable. The development of a solvent-free UV-curable type has become mainstream.

As the one-part cold curing type coating agent, one-part cold curing by reaction between a carbonyl group based on a keto group or an ald group and an organic dihydrazide compound as described in JP-A-10-265729 is known. Mold resins are being launched on the market.

[0005]

However, the coating agent of the above type has a problem in that although it has water resistance, it is inferior in solvent resistance. In order to improve the solvent resistance of this type of resin, internal crosslinking with a polyfunctional monomer is required. However, when the internal crosslinking is carried out by the method described in the above-mentioned publication, the viscosity is often increased or gelled during the production, and commercialization is often impossible.

Accordingly, an object of the present invention is to provide a one-part, room-temperature-curable aqueous resin emulsion composition having excellent water resistance and solvent resistance.

[0007]

The present invention provides (A)
A self-emulsifying polyurethane resin comprising: (a) a polymerizable double bond-containing monomer containing a carbonyl group in a molecule; and (b) a polyfunctional monomer having two or more polymerizable double bonds. The above-mentioned problem has been solved by producing an aqueous resin emulsion obtained by copolymerizing the compound as a seed polymer and (B) an organic polyhydrazide compound containing at least two hydrazide groups in the molecule.

[0008] The aqueous resin emulsion composition obtained from the above composition is a one-pack type. In addition, since the seed polymer is used, and the component (A) is partially cross-linked with the component (b) and the component (B) is cross-linked again with the organic polyhydrazide compound, gelation occurs. The water resistance and the solvent resistance of the resulting aqueous resin emulsion can be improved while preventing the occurrence of water.

[0009]

Embodiments of the present invention will be described below.

The aqueous resin emulsion composition according to the present invention comprises: an aqueous resin emulsion comprising a predetermined component as the component (A); and an organic polyhydrazide having at least two hydrazide groups in the molecule as the component (B). It is a one-part, room temperature-curable aqueous resin emulsion composition obtained from a compound.

The component (A) has a polymerizable double bond-containing monomer containing a carbonyl group in the molecule as the component (a) and two or more polymerizable double bonds as the component (b). A polyfunctional monomer having, and if necessary, (c)
It is obtained by copolymerizing a polymerizable double bond-containing monomer copolymerizable with the component (a) and the component (b) with a self-emulsifying polyurethane resin as a seed polymer.

The polymerizable double bond-containing monomer as the component (a) includes a carbonyl group comprising a keto group or an ald group,
And a monomer containing a polymerizable double bond in the molecule,
Specific examples include acrolein, diacetone acrylamide, vinyl methyl ketone, diacetone (meth) acrylate, acetoacetoxyethyl (meth) acrylate, and the like. Among these, diacetone acrylamide is preferred from the viewpoint of copolymerizability with other unsaturated monomers.

The polyfunctional monomer as the component (b) is
A monomer having at least two or more polymerizable double bonds as a functional group. Examples thereof include di (meth) acrylates, tri (meth) acrylates, and divinyl monomers such as divinylbenzene. can give.

The mixing ratio of the above components (a) and (b) is as follows:
The mixing ratio is preferably 1.33 ≦ (a) / (b) ≦ 6. If this ratio is less than 1.33, the crosslinking density becomes high and gelation is likely to occur, making the production difficult. If it is more than 6, the room temperature curability becomes remarkable and the pot life may be shortened. .

The polymerizable double bond-containing monomer as the component (c) is a monomer having a polymerizable double bond copolymerizable with the components (a) and (b). Examples include (meth) acrylic esters such as methyl methacrylate, butyl acrylate and 2-ethylhexyl acrylate, vinyl esters such as vinyl acetate, and styrene.

In addition to the above components (a) to (c), if necessary, an unsaturated carboxylic acid may be added. Examples of the unsaturated carboxylic acid include (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid and the like.

When each of the components (a) to (c) is used as the monomer constituting the component (A), the mixing ratio of each component is determined by the sum of the components (a) to (c). For quantity,
Component (a) is preferably from 3.0 to 20.0% by weight, and 5.0% by weight.
~ 15.0% by weight is preferred. If the amount is less than 3.0% by weight, the room-temperature curability may decrease, and the water resistance may deteriorate. On the other hand, if it is more than 20.0% by weight, the emulsified state becomes unstable and gelation may be easily caused. (B)
The components are preferably 0.5-15.0% by weight, and 1.0-1% by weight.
0.0% by weight is preferred. If it is less than 0.5% by weight,
In some cases, the crosslink density becomes low and the solvent resistance deteriorates, and when it is more than 15.0% by weight, gelation may easily occur during the reaction. The component (c) contains 65.
0 to 96.5% by weight, preferably 85.0 to 94.0% by weight
Is preferred. When the amount is less than 65.0% by weight, both components (a) and (b) are relatively increased, and thus the influence of each increase or decrease may be remarkable. On the other hand, 9
If the amount is more than 6.5% by weight, the solvent resistance and the room temperature curability, which are features of the present invention, tend to be insufficient.

The above-mentioned seed polymer comprises particles of a self-emulsifying polyurethane resin. This self-emulsifying polyurethane resin is composed of an organic polyisocyanate compound and polyols. The organic polyisocyanate compound is not particularly limited, and various conventionally known organic polyisocyanate compounds such as aromatic, aliphatic and alicyclic diisocyanates can be used. The polyols are those used in general urethane products, and for example, any of polyethers, polyesters, polycarbonates, polyesteramides, polythioethers, polybutadiene glycols and the like can be used.

The self-emulsifying polyurethane resin can be obtained by conducting a chain extension reaction with a known urethane-forming reaction and various conventionally known chain extenders for urethane. That is, it is a resin in which a urethane prepolymer obtained by reacting an organic polyisocyanate compound having at least two isocyanate groups with a polyol is chain-extended in water with a chain extender for urethane to further polymerize. Since the chain is extended in water, the resulting resin is a self-emulsifying aqueous polyurethane resin composition.

The particle size of the seed polymer obtained is 0.5 μm.
m or less, and preferably 0.03-0.3 μm. 0.
If it is larger than 5 μm, the emulsion stability during polymerization tends to be insufficient. Further, when the thickness is in the range of 0.03 to 0.3 μm, the emulsion stability during polymerization is further improved.

The aqueous resin emulsion as the component (A) is prepared by adding a known emulsifier to the above-mentioned seed polymer, and adding each of the above-mentioned monomers blended at a predetermined ratio.
It is manufactured by conducting a polymerization reaction at 0 ° C. for about 120 to 480 minutes.

At this time, the amount of the seed polymer added is 2.0 to 100.0% by weight based on the total amount of the above monomers.
Is preferably 2.0 to 35.0% by weight, and 2.0 to 35.0% by weight.
25.0% by weight is more preferred. If the content is less than 2.0% by weight, gelation, thickening, and the like are likely to occur due to intra-particle crosslinking by the polyfunctional monomer, and the instability of the resulting aqueous resin emulsion cannot be suppressed.
If the amount is more than 0.0% by weight, the character of the seed polymer comes out as it is, which does not improve the water resistance and the solvent resistance and also leads to an increase in cost.

The organic polyvalent dihydrazide compound as the component (B) is a compound containing at least two, that is, two or more hydrazide groups in a molecule,
Examples include oxalic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, 1,3-bis (hydrazinocarboxyethyl) -5-isopropylhydantoin, and the like. Examples of the hydrazide compound having three or more functional groups include trihydrazide of pyromellitic acid, trihydrazide of nitrilotriacetic acid, tetrahydrazide of ethylenediaminetetraacetic acid, pentane-1,3,5-tricarboxylic acid trihydrazide, and hexene-4-1. 2,
6-tricarboxylic trihydrazide, 3-cyanopentane-1,3,5-tricarboxylic trihydrazide and the like can be mentioned. When the hydrazide compound having three or more functional groups is used, the crosslink density can be increased, so that it is expected that the water resistance is improved. However, when the number of hydrazide groups is excessively large, the number of hydrazide groups that cannot participate in crosslinking due to steric hindrance increases, and the water resistance may be rather reduced.

These organic polyhydrazide compounds can be used alone or in combination of two or more.

Among these, adipic dihydrazide and 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin are preferred from the viewpoint of solubility in water.

The mixing ratio of the above components (A) and (B) is as follows:
It is preferable to add (B) an organic polyhydrazide compound so that the hydrazide group becomes 0.1 to 3.0 equivalents per 1 equivalent of the carbonyl group in the resin component contained in the aqueous resin emulsion (A). Well, 0.3 to 2.0 equivalents are preferred. If it is less than 0.1 equivalent, the curability will be insufficient, and if it is more than 3.0 equivalent, the water resistance tends to decrease.

By adding the component (B) to the component (A), the component (B) causes crosslinking within the component (A),
The resin component of the resulting aqueous resin emulsion composition is cured. At this time, if a ketone-based organic solvent containing a carbonyl group is added at the same time, the crosslinking reaction can be delayed, and the curing rate of the resin component of the obtained aqueous resin emulsion composition can be controlled, so that the one-liquid state is more stable. Can be changed.

Examples of the ketone-based organic solvent containing a carbonyl group include diacetone alcohol, acetonylacetone, and acetone alcohol in view of solubility in water and a boiling point higher than that of water. Among them, diacetone alcohol is preferred from the viewpoint of water resistance after curing.

The amount of the ketone-based organic solvent added is such that the carbonyl group of the ketone-based organic solvent is 1 to 3 equivalents to 1 equivalent of the hydrazide group in the organic polyhydrazide compound (B). The amount is preferably 1.3 to 2.5 equivalents. If the amount is less than 1 equivalent, the effect of suppressing the curing may be insufficient, and the stability of the one-component state may be insufficient. On the other hand, when the amount is more than 3 equivalents, an excessive solvent may remain in the coating film, and the solvent resistance and the like may be deteriorated.

The glass transition point (Tg) of the obtained aqueous resin emulsion composition is preferably from -20 to 50 ° C., and from 0 to 3 ° C.
0 ° C. is preferred. If the Tg is lower than -20 ° C, tack that cannot be suppressed even by crosslinking within the particle and curing at room temperature may occur, and adverse effects such as blocking may occur. In addition, Tg is 50
If the temperature is higher than 0 ° C., the conditions of intra-particle crosslinking and curing at room temperature are added even though film formation is difficult due to high Tg, so that film formation tends to be difficult.

Incidentally, Tg can be measured by a differential scanning calorimeter (DSC) using a film formed at normal temperature.

The viscosity of the resulting aqueous resin emulsion composition is preferably from 10 to 2000 mPa · s. Outside this range, sagging may occur or the material may be too hard, resulting in poor workability during coating. The pH is 5.5 to 5.5.
8.5 is better. Outside this range, the stability of the emulsified state may be insufficient. Furthermore, the non-volatile content is 30 to 5
5% is good. When the concentration is out of this range, if the concentration is low, it may be difficult to adjust the film thickness after coating, or the drying may be slow, while if the concentration is high, the stability of the emulsified state is insufficient, and In some cases, the viscosity increases and the workability deteriorates.

[0033]

EXAMPLES The invention relating to this aqueous resin emulsion will be described in more detail with reference to examples.

(Example 1) 900 g of ion-exchanged water was placed in a 2 liter flask equipped with a stirrer, a reflux condenser and a raw material inlet, and Eleminol ES-70 as a surfactant.
(Sanyo Chemical Industries, polyoxyethylene alkyl phenyl ether sulfate-based anionic surfactant) 30
g, Neo of self-emulsifying polyurethane as seed polymer
rez R-9621 (manufactured by Avicia, solvent-free, nonvolatile content: 40%, particle diameter: 0.06 μm, hereinafter referred to as “R-96
21 ". ) 240 g, ammonium persulfate 18 as a polymerization initiator while maintaining the internal temperature at 75 ° C.
g was added.

Next, as the component (c), 102 g of styrene (hereinafter abbreviated as “SM”), 276 g of n-butyl acrylate (hereinafter abbreviated as “BA”), and 2
-Ethylhexyl acrylate (hereinafter abbreviated as "2EHA") 72 g, diacetone acrylamide (hereinafter abbreviated as "DAAm") 120 as component (a) 120
g, divinylbenzene (hereinafter referred to as “DV”)
B ”. ), A mixture of 12 g of methacrylic acid (hereinafter abbreviated as “MAA”) as an unsaturated carboxylic acid and 12 g of n-octylmercaptan was dropped into the flask over 2 hours. After completion of the dropwise addition, 12 g of a 5% aqueous solution of ammonium persulfate was added, and the internal temperature was adjusted to 80%.
Aged at 2 ° C for 2 hours. After cooling the obtained emulsion to 25 ° C., 6 g of 25% aqueous ammonia is added as a neutralizing agent with stirring, and after a while, adipic dihydrazide (hereinafter abbreviated as “ADH”) as a component (B). .) To 60
g, diacetone alcohol as a ketone organic solvent
After adding 20 g and stirring, the pH was 6.5 and the nonvolatile content was 42.1.
% Of the desired aqueous resin emulsion composition. The following performance tests were performed using the obtained aqueous resin emulsion composition. Table 1 shows the results.

[Performance test] Stability of standing at 50 ° C. The above aqueous resin emulsion was placed in a thermostat at 50 ° C. for 10 minutes.
After standing for a day, the state after returning to room temperature (25 ° C.) was confirmed. ◎: No increase in viscosity or separation / aggregation and sedimentation of resin were observed. ○: No separation / aggregation and sedimentation of resin was observed.
Viscosity of about 2 times is observed △: Viscosity is 3 times or more, separation or sedimentation of resin is observed ×: Emulsion is coated on gelled water-resistant glass plate, and film is dried A coating film having a thickness of 40 μm was prepared, dried at 100 ° C. for 3 minutes, left at room temperature for one day, and then a few drops of water were dropped on the coating film using a spoid, and the surface state after 16 hours was observed. ：: No abnormality △: Partially whitened coating ×: Completely whitened coating ××: Dissolved ethanol or kerosene oil A few drops were dropped by using, and the surface state after 16 hours was observed. ：: No abnormality at all ○: The coating film did not dissolve, but slight whitening was observed Δ: The coating film did not dissolve, but whitened ×: The coating film dissolved

(Examples 2 to 11 and Comparative Examples 1 to 6) An aqueous resin emulsion composition was obtained in the same manner as in Example 1 except that the components shown in Table 1 or Table 2 were used. The above-mentioned performance test was performed using the obtained aqueous resin emulsion composition. The results are shown in Tables 1 and 2.

In Tables 1 and 2, AMA means allyl methacrylate, MMA means methyl methacrylate, and NS-400 means acrylic-modified polyester-based polyurethane (manufactured by Nikka Chemical Co., Ltd .: Neo sticker, particle size 0.08 μm, Solvent-free, nonvolatile content 40%).

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

According to the present invention, the seed polymer is used, the component (A) is partially cross-linked with the component (b), and the organic polyhydrazide compound (B) is used again. Since cross-linking occurs, gelation can be prevented, and the water resistance and solvent resistance of the resulting aqueous resin emulsion can be improved.

The resulting aqueous resin emulsion is
It is a one-part cold curing type.

Further, this aqueous resin emulsion can be used as various coating agents, coating agents for plastic films and the like.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // C08F 20/00 C08F 20/00 F term (reference) 4J002 BC031 BF021 BG041 BG061 BN171 EQ026 GH01 GH02 HA07 4J011 JA03 JA06 JA13 JB16 JB22 PA95 PC02 PC07 4J026 AB02 AC36 BA05 BA07 BA12 BA20 BA25 BA27 BA28 BA30 BA32 BA34 BB03 BB04 BB10 DB04 DB14 DB26 DB28 FA04 GA08

Claims (10)

[Claims] (A) (a) a polymerizable double bond-containing monomer containing a carbonyl group in a molecule, and (b) a polyfunctional monomer having two or more polymerizable double bonds. , An aqueous resin emulsion obtained by copolymerizing a self-emulsifying polyurethane resin as a seed polymer, and (B) an aqueous resin emulsion obtained from an organic polyhydrazide compound containing at least two hydrazide groups in the molecule. Composition. 2. The aqueous resin emulsion (A) comprises (a) a polymerizable double bond-containing monomer and (b) a polyfunctional monomer, and (c) (a) and (b) The aqueous resin emulsion composition according to claim 1, which is an aqueous emulsion obtained by adding a polymerizable double bond-containing monomer copolymerizable with (a). 3. The mixing ratio of (a) a polymerizable double bond-containing monomer and (b) a polyfunctional monomer in the aqueous resin emulsion (A) is 1.33 ≦ (a) / ( 3. The aqueous resin emulsion composition according to claim 1, wherein b) ≦ 6 (weight ratio). 4. The (A) aqueous resin emulsion of (a) a polymerizable double bond-containing monomer, (b) a polyfunctional monomer, and (c) a polymerizable double bond-containing monomer. (A) The polymerizable double bond-containing monomer is used in an amount of 3.0 to 20.
0% by weight, (b) 0.5 to 15.0% by weight of a polyfunctional monomer, and (c) 65.0 to 9 of a polymerizable double bond-containing monomer.
The aqueous resin emulsion composition according to claim 2, which contains 6.5% by weight. 5. The seed polymer is added in an amount of 2.0 to 1 based on the total amount of each monomer constituting the aqueous resin emulsion (A).
The aqueous resin emulsion composition according to any one of claims 1 to 4, which contains 00.0% by weight. 6. The urethane prepolymer obtained by reacting the seed polymer with an organic polyisocyanate compound having at least two isocyanate groups and a polyol is subjected to chain extension in water with a urethane chain extender. The aqueous resin emulsion composition according to any one of claims 1 to 5, which is a self-emulsifying aqueous polyurethane resin composition further polymerized. 7. An organic polyhydrazide compound (B) is used in an amount of 0.1% per equivalent of the carbonyl group in the resin component contained in the aqueous resin emulsion (A).
The aqueous resin emulsion composition according to any one of claims 1 to 6, wherein the aqueous resin emulsion composition is added so as to have a weight of from 3.0 to 3.0 equivalent. 8. The method according to claim 1, wherein the organic polyhydrazide compound (B) has at least two hydrazide groups.
An aqueous resin emulsion composition according to any one of claims 1 to 7. 9. A ketone-based organic solvent containing a carbonyl group is added so that the carbonyl group is 1 to 3 equivalents to 1 equivalent of the hydrazide group in the organic polyhydrazide compound (B). An aqueous resin emulsion composition according to any one of claims 1 to 8. 10. The particle size of the seed polymer is 0.5 μm.
The aqueous resin emulsion composition according to any one of claims 1 to 9, wherein