JP2522699B2 - Aqueous varnish dispersion for press coat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a dispersion for an aqueous varnish for press coating,
More specifically, it relates to a dispersion liquid for an aqueous varnish for a press coat, which has excellent miscibility with alcohol and has good crushability, gloss and blocking resistance.

[Conventional technology]

Conventionally, it is well known to apply a resin solution to a printed paper for the purpose of polishing and press it.

As a resin solution (press coat varnish) for polishing press-printing of such a paper print, (meth)acrylic acid ester, styrene-based monomer, vinyl acetate ) A varnish in which a polymer is dissolved in an aromatic organic solvent or the like is used. However, since these varnishes use organic solvents,
There are problems such as environmental pollution and fire risk.

Therefore, recently, varnishes for press coats have been made water-based, and various monomers such as (meth)acrylic acid ester and styrene-based monomers are used as an aqueous resin solution (dispersion liquid for aqueous varnishes for press coats). Aqueous solutions and aqueous dispersions of polymers obtained by copolymerization have been proposed (JP-A-62-282).
095, JP-A-62-282096).

However, conventional aqueous dispersions for press coats have an insufficient balance of various properties such as gloss, crushability and blocking resistance. Further, the aqueous varnish dispersion for press coat is usually used by mixing alcohols in order to improve the drying speed, but the conventional one has a problem that the alcohol miscibility is poor. ..

[Problems to be Solved by the Invention]

An object of the present invention is to provide a dispersion liquid for an aqueous varnish for a press coat, which is excellent in miscibility with alcohol and has well-balanced crushability, gloss and blocking resistance.

The present inventors have conducted extensive studies to solve the problems of the prior art, the acid value obtained by copolymerizing an ethylenically unsaturated monomer mixture containing an ethylenically unsaturated carboxylic acid is 50 ~ A water-soluble or water-dispersible resin obtained by neutralizing 300 resins is used as an emulsion stabilizer, and in the presence of the neutralizing resin, 0.05 to 0.5% by weight of a glycidyl group-containing ethylenically unsaturated monomer is used. It was found that an aqueous dispersion obtained by copolymerizing an ethylenically unsaturated monomer mixture containing the same can achieve the above object, and based on this finding, the present invention has been completed.

[Means for solving the problem]

Thus, according to the present invention, a resin obtained by neutralizing a resin having an acid value of 50 to 300 obtained by copolymerizing an ethylenically unsaturated monomer mixture containing an ethylenically unsaturated carboxylic acid (A In the presence of ), a press containing an aqueous dispersion obtained as a main component by copolymerizing an ethylenically unsaturated monomer mixture (B) containing 0.05 to 0.5% by weight of a glycidyl group-containing ethylenically unsaturated monomer. Dispersions for aqueous varnishes for coatings are provided.

Hereinafter, the present invention will be described in detail.

[Neutralizing resin (A): emulsion stabilizer]

In the present invention, as an emulsion stabilizer, an acid value obtained by copolymerizing an ethylenically unsaturated monomer mixture containing an ethylenically unsaturated carboxylic acid, a resin obtained by neutralizing a resin of 50 to 300 Use (A).

The resin (A) is prepared by first copolymerizing an ethylenically unsaturated monomer mixture containing an ethylenically unsaturated carboxylic acid by solution polymerization or bulk polymerization according to a conventional method, and then converting the carboxyl group into ammonia or ammonia. It can be obtained by neutralizing equivalent or partial amount with an organic amine or the like to obtain a water-soluble or water-dispersible resin. The resin (A) is dissolved or dispersed in water and used as an emulsion stabilizer. The copolymer obtained by solution polymerization in an organic solvent can be made into an aqueous dispersion (water-based) by adding water at the same time as or before and after the neutralization treatment and removing the organic solvent. desirable. In addition, it is preferable that the neutralization resin (A) is neutralized with an equivalent amount of a carboxyl group to be a water-soluble resin in order to act as an emulsion stabilizer.

Examples of the ethylenically unsaturated carboxylic acid include carboxyl group-containing ethylenically unsaturated monomers such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid and itaconic acid.

Examples of the ethylenically unsaturated monomer other than the ethylenically unsaturated carboxylic acid include styrene-based monomers such as styrene, α-methylstyrene, vinyltoluene, pt-butylstyrene and chlorostyrene; methyl acrylate. ,
Ethyl acrylate, propyl acrylate, butyl acrylate, isobutyl acrylate, n-amyl acrylate,
Isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate,
Acrylic acid ester monomers such as 2-hydroxyethyl acrylate and hydroxypropyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, Methacrylic ester monomers such as n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate; acrylamide, N-methylol acrylamide, N-butoxymethyl acrylamide And other acrylamide-based monomers; methacrylamide-based monomers such as methacrylamide, N-methylolmethacrylamide, and N-butoxymethylmethacrylamide.

The resin having an acid value of 50 to 300 can be obtained by conventionally known solution polymerization or bulk polymerization of an ethylenically unsaturated monomer containing an ethylenically unsaturated carboxylic acid. Solution polymerization is preferred. Organic solvents for solution polymerization include alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol and butyl alcohol; ethers such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; esters such as methyl acetate and ethyl acetate. Aromatic hydrocarbons such as toluene and xylene can be used.
The polymerization conditions are usually a polymerization temperature of 50 to 150° C. and a polymerization time of about 1 to 10 hours in the presence of a radical polymerization initiator.

The resin obtained by copolymerizing an ethylenically unsaturated monomer containing an ethylenically unsaturated carboxylic acid needs to have an acid value in the range of 50 to 300, and has an acid value of 80 to 200. Is preferred.

When the acid value is less than 50, the water solubility of the resin is insufficient and the emulsion stability during polymerization of the ethylenically unsaturated monomer mixture (B) containing the glycidyl group-containing ethylenically unsaturated monomer On the contrary, when the acid value is larger than 300, the water resistance of the dispersion for a water-based varnish for press coating decreases, and the peelability from the endless stainless steel plate during press coating is poor. It is inferior in practicality.

The type and composition of each monomer is not particularly limited as long as it contains an ethylenically unsaturated carboxylic acid as a copolymerization component and the acid value is within the above range, but the neutralizing resin (A) is used as an emulsion stabilizer. Since it serves as a film-forming component as well as being used, it is preferably determined in consideration of the emulsion stabilizing action and film-forming property. Therefore, considering the solubility of the resin in water and the gloss, water resistance, and blocking resistance of the film after pressing, for example, 10 to 40% by weight of ethylenically unsaturated carboxylic acid, 5 to 40% of styrenic monomer are used. A monomer mixture containing 10% by weight, 10 to 75% by weight of the (meth)acrylic acid ester-based monomer, and 0 to 10% by weight of the (meth)acrylamide-based monomer is preferable.

For neutralization, ammonia or organic amine is usually used as a neutralizing agent. As the organic amine, methylamine, ethylamine, isopropylamine, dimethylamine, 2-dimethylethanolamine, diisopropylamine, trimethylamine, triethanolamine or the like or a mixture thereof is used. Water-soluble neutralizing agents may be used as an aqueous solution. Neutralization is
The water-soluble or water-dispersible neutralized resin (A) is obtained by neutralizing the carboxyl group in the resin in an amount equivalent to or partially neutralized.

The neutralization treatment in the resin (A) is carried out by allowing a neutralizing agent to exist in the reaction system when copolymerizing the ethylenically unsaturated monomer mixture (B) containing the glycidyl group-containing ethylenically unsaturated monomer. Although it can be carried out, the carboxyl group-containing resin obtained by copolymerization in an organic solvent such as alcohol is usually
From the viewpoint of operation, it is preferable to use a solution or an aqueous dispersion in advance by performing a neutralization treatment, adding water and removing an organic solvent.

When the neutralizing resin (A) is used as an aqueous solution or an aqueous dispersion, the resin concentration is usually 20 to 30%.

[Ethylenically unsaturated monomer mixture (B) containing glycidyl group-containing ethylenically unsaturated monomer]

The monomer mixture copolymerized in the presence of the neutralization resin (A) as an emulsion stabilizer contains 0.05 to 0.5% by weight of an glycidyl group-containing ethylenically unsaturated monomer as an essential component, preferably
It is an ethylenically unsaturated monomer mixture (B) containing 0.2 to 0.4% by weight.

As the glycidyl group-containing ethylenically unsaturated monomer,
Examples thereof include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, methallyl glycidyl ether, vinyl glycidyl ether, butadiene monooxide, and vinylcyclohexene monoxide.

Examples of the ethylenically unsaturated monomer other than the glycidyl group-containing ethylenically unsaturated monomer include styrene and α-
Styrene-based monomers such as methylstyrene, vinyltoluene, pt-butylstyrene and chlorostyrene; methyl acrylate, ethyl acrylate, propyl acrylate,
Butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, p acrylate
-Acrylic ester monomers such as octyl, 2-hydroxyethyl acrylate, hydroxypropyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, methacryl Isoamyl acid, n-hexyl methacrylate, 2-methacrylic acid
Methacrylate ester monomers such as ethylhexyl, n-octyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate; acrylamide monomers such as acrylamide, N-methylolacrylamide, N-butoxymethylacrylamide; methacrylamide. , N-methylol methacrylamide, N
-Methacrylamido-based monomers such as butoxymethylmethacrylamide; (meth)acrylonitrile-based monomers such as acrylonitrile and methacrylonitrile, and the like, which can be copolymerized with glycidyl group-containing ethylenically unsaturated monomers There is no particular limitation as long as it is an ethylenically unsaturated monomer.

The proportion of the glycidyl group-containing ethylenically unsaturated monomer in the monomer mixture is 0.05 to 0.5% by weight.

If the amount of the glycidyl group-containing ethylenically unsaturated monomer used is less than 0.05% by weight, the alcohol miscibility or storage stability of the resulting aqueous dispersion will be reduced, and other ethylenically unsaturated monomers that will be copolymerized will be reduced. The blocking resistance of the coating becomes poor depending on the type of the monomer. On the other hand, when the proportion of the glycidyl group-containing ethylenically unsaturated monomer used is more than 0.5% by weight, the crushability and gloss of the film when used as a dispersion liquid for an aqueous varnish for press coat are deteriorated. Furthermore, depending on the copolymerization composition and molecular weight of the neutralization resin (A) used as an emulsion stabilizer, the viscosity of the reaction system during polymerization increases, making it difficult to obtain the desired aqueous dispersion.

The type and composition ratio of the ethylenically unsaturated monomer containing the glycidyl group-containing ethylenically unsaturated monomer should be such that the glass transition temperature Tg of the resulting copolymer falls within the range of 50°C to 80°C. Is preferable in order to secure blocking resistance while imparting crushability and glossiness. Then, considering the crushability, gloss, water resistance, blocking resistance and the like of the coating film after pressing with the alcohol miscibility and the obtained aqueous dispersion, for example, a glycidyl group-containing ethylenically unsaturated other-mer. 0.05-0.5% by weight, styrene monomer 5
〜60wt% (meth)acrylic acid ester monomer 10〜85
It is preferably a mixture of dimers containing wt%.

The ethylenically unsaturated monomer mixture containing the glycidyl group-containing ethylenically unsaturated monomer is polymerized in the presence of the neutralizing resin (A), and the neutralizing resin (A) and the glycidyl group-containing compound used for the polymerization are included. The weight ratio with the ethylenically unsaturated monomer mixture (B) containing the ethylenically unsaturated monomer is the neutralization resin (A).
The action of the emulsion stabilizer as an emulsion stabilizer is (A): in consideration of the solid content concentration of the emulsion, the characteristics of the coating film after pressing, and the like.
The ratio of (B) is 10/90 to 90/10, preferably 20/80 to 50/50
Is selected from the range.

(Polymerization method) The method for polymerizing the ethylenically unsaturated monomer mixture (B) containing the glycidyl group-containing ethylenically unsaturated monomer in the presence of the neutralization resin (A) as an emulsion stabilizer is, for example, ,
It may be batch polymerized in an aqueous medium using a radical polymerization initiator, or may be prepared by emulsifying the ethylenically unsaturated monomer mixture (B) with the neutralizing resin (A) in advance and then continuously reacting. It may be added to a vessel and polymerized. However, when it is used as a dispersion for an aqueous varnish for press coating, and when it is desired to be in the form of fine particles, it is used by emulsifying the ethylenically unsaturated monomer mixture (B) with the neutralizing resin (A) beforehand. Preferably. By doing so, a more stable and uniform aqueous dispersion of the fine particle polymer can be obtained.

The polymerization temperature is 0 to 100°C, preferably 30 to 80°C, and the polymerization time is 1 to 20 hours.

Radical polymerization initiators include water-soluble initiators such as potassium persulfate, ammonium persulfate, and hydrogen peroxide; benzoyl peroxide, di-t-butyl peroxide, 2,2-azobis-2,4-dimethylvaleronitrile, and the like. Oil-soluble initiators, such as redox initiators in which a peroxide is combined with a reducing agent such as sodium bisulfite and triethanolamine. The amount of the radical polymerization initiator used is usually in the range of 0.05 to 5 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated monomer mixture (B).

(Aqueous Dispersion) The aqueous dispersion obtained as described above is excellent in alcohol miscibility, and the aqueous dispersion for a press varnish containing this as a main component is crushable, glossy or anti-blocking. The balance of sex is excellent.

In addition, an alkali-soluble resin may be added to the aqueous dispersion, if necessary. As the alkali-soluble resin, a resin corresponding to the neutralization resin (A) of the emulsion stabilizer is suitable. The amount thereof used is a total amount of the neutralizing resin (A) used as an emulsion stabilizer during the polymerization, and the weight ratio to the ethylenically unsaturated monomer mixture (B) is (A):
The range in which (B) is 10/90 to 90/10, preferably 20/80 to 50/50 is preferable.

If the proportion of the neutralizing resin (A) used is too large as a whole, the solid content concentration of the aqueous dispersion becomes low, and the gloss of the coating becomes
Crushability is reduced. Further, if the proportion of the neutralizing resin (A) used is too small from the polymerization stage, not only the particle size increases but also the emulsion stability during polymerization decreases. On the other hand, if the amount of the neutralizing resin (A) is too small as a whole, there arises a problem in the leveling property after coating, which deteriorates the smoothness of the coating and makes the appearance after press working unsatisfactory.

(Dispersion for aqueous varnish for press coat) The dispersion for aqueous varnish for press coat of the present invention is a dispersion containing the aqueous dispersion as a main component.

If necessary, various additives such as a release agent for improving peeling from the press plate, a wax component for improving abrasion resistance, or a defoaming agent can be added to the dispersion liquid.

Further, the dispersion can be used as it is as a dispersion for press coating, but alcohols such as isopropyl alcohol are usually added to the dispersion for improving the drying speed.
It can be used by adding it in the range of about 10 to 30 parts by weight with respect to 100 parts by weight.

The aqueous dispersion for press coating aqueous varnish of the present invention is applied by roll coating, gravure printing, flexographic printing, offset printing or the like on the printing surface of the printed paper, and usually 50 to 100° C. for 2 to 6 seconds. To be dried. After drying, a coating layer (coating) having a thickness of 1 to 7 μm is formed. The printing paper having this coating layer is generally 90 to 120° C. and 200 to 300 kg/c by an endless press machine or the like.
Pressed at m ² and line speed of 10-30m/min.

〔Example〕

The present invention will be described more specifically below with reference to Examples, Reference Examples and Comparative Examples. Parts and% in the examples, reference examples and comparative examples are based on weight unless otherwise specified.

<Measurement Methods of Physical Properties> The measurement methods of various physical properties in Examples, Reference Examples and Comparative Examples are as follows.

Acid value: Determined as mg of potassium hydroxide required to neutralize (titrate) 1 g of resin with phenolphthalein as an indicator.

Alcohol miscibility: The change in viscosity of the aqueous dispersion to which alcohol was added was examined and evaluated in the following two stages.

X: When the viscosity changes drastically.

○: When the change in viscosity is small.

Crushability: After pressing the printing paper, visually observing the surface state of the coating layer (aqueous dispersion liquid coating layer), comprehensively judging the whiteness, smoothness, etc. evaluated.

◯: The surface is smooth and has a transparent feeling.

Δ: The coating layer has some whitish parts.

X: Many whitish parts and no smoothness.

Gloss: According to JIS K-5400, the gloss value of the coating layer at a 60° reflection angle was used.

Blocking resistance: The coating layers of the printing papers were overlapped with each other and the ease of peeling after standing for 24 hours was examined. The standing conditions are 50° C., 80% relative humidity, and a load of 500 g/cm ² . The ease of peeling was evaluated according to the following three grades and used as an index of blocking resistance.

○: It easily peels off when touched.

Δ: It peels when peeled by hand.

X: The coating layer is destroyed when peeled off.

[Reference Example 1] Synthetic experiment example of neutralizing resin (A) 100 parts of isopropyl alcohol was charged into a reactor at 80°C.
The mixture of ethylenically unsaturated monomers shown in Table 1 after being heated to
100 parts and 2,2-azobis- as a radical polymerization initiator
Four parts of 2,4-dimethylvaleronitrile were continuously added to the reactor over a period of 4 hours. Then, the reaction was continued for 2 hours to complete the polymerization. After cooling, ammonia water necessary for neutralization,
Four times the amount of water (weight ratio) of the resin was added, and then heated to 90° C. or higher to distill off isopropyl alcohol and excess water, and an aqueous neutralized resin (A-1 to ( A-
A solution of 6) was obtained.

Table 1 shows the charged composition of the ethylenically unsaturated monomer mixture and the acid value of the resin.

[Example 1] A reactor equipped with a cooler, an inert gas introducing pipe, a dropping device and a stirrer contained 60 parts of deionized water and 5 parts of an aqueous neutralizing resin (A-1) as an emulsion stabilizer ( The aqueous solution of A-1) was charged and the temperature was maintained at 70° C. with stirring.

In a nitrogen gas stream, a vinyl-based monomer mixture consisting of 20 parts of styrene, 45 parts of methyl methacrylate, 34.6 parts of butyl methacrylate, and 0.4 parts of glycidyl methacrylate was previously treated with 140 parts of a 25% aqueous solution of the neutralizing resin (A-1). The emulsified dispersion and a solution of 1.5 parts of ammonium persulfate in 15 parts of deionized water were separately and continuously added dropwise to the reactor heated to 70° C. over 3 hours. After dropping, the reaction was continued at 85° C. for 2 hours to obtain a milky white aqueous dispersion having a solid content of 40% and a viscosity of 400 cps.

To the obtained aqueous dispersion, 10 parts of the neutralizing resin (A-1) (dry weight of resin content), 2.0 parts of a release agent (phosphate ester type sea surface active agent), 0.3 part of polyethylene wax, 30 parts of isopropyl alcohol were added. It was added to obtain a dispersion liquid for an aqueous varnish for press coat. The proportion of the total resin content of the neutralizing resin (A-1) and the copolymer of the vinyl monomer mixture (B) containing glycidyl methacrylate in the dispersion for press coat aqueous varnish is (A). ): Looking at the ratio of (B), it is 31:6
It was 9 (weight ratio).

The obtained aqueous dispersion for press coating varnish was applied onto general printing paper by a roll coating method so that the thickness after drying was 5 μm, and dried at 80° C. for 3 seconds. Then, it was pressed with an endless press at 120° C., 250 kg/cm ² , and a line speed of 20 m/min.

[Example 2] An ethylenically unsaturated monomer mixture having the same composition as in Example 1 was copolymerized in the same formulation as in Example 1 using the aqueous neutralizing resin (A-2) as an emulsion stabilizer. Thus, an emulsion-colored aqueous dispersion having a solid content of 40% and a viscosity of 460 cps was obtained. Using the obtained dispersion, the same treatment as in Example 1 was carried out and a press working treatment was carried out.

[Example 3] Using an aqueous neutralizing resin (A-3) as an emulsion stabilizer, 50 parts of styrene, 32.7 parts of methyl methacrylate, 17 parts of 2-ethylhexyl acrylate and 0.3 part of glycidyl methacrylate as an ethylenically unsaturated monomer mixture. Except that parts were used, the solid content was 40% and the viscosity was 700 cps in the same manner as in Example 1.
A milky white aqueous dispersion was obtained, and the same dispersion formulation as in Example 1 was obtained to obtain an aqueous varnish dispersion for press coating.

Using the resulting dispersion for press coat aqueous varnish,
The pressing process was performed in the same manner as in Example 1.

[Example 4] Using an aqueous neutralizing resin (A-4) as an emulsion stabilizer, 35 parts of styrene, 33 parts of methyl methacrylate, 31.6 parts of butyl methacrylate as an ethylenically unsaturated monomer mixture,
A milky white aqueous dispersion having a solid content of 40% and a viscosity of 400 cps was obtained in the same manner as in Example 1 except that 3 parts of 2-ethylhexyl acrylate and 0.4 part of glycidyl methacrylate were used, and the same formulation as in Example 1. Thus, a dispersion liquid for an aqueous varnish for press coat was obtained.

Using the resulting dispersion for press coat aqueous varnish,
The pressing process was performed in the same manner as in Example 1.

[Comparative Example 1] An ethylenically unsaturated monomer mixture having the same composition as in Example 1 was polymerized and solidified by the same formulation as in Example 1 except that an aqueous neutralizing resin (A-5) was used as an emulsion stabilizer. Mold 40%, viscosity 660c
A ps milky white aqueous dispersion was obtained.

When the obtained dispersion was subjected to the same treatment as in Example 1 and subjected to a press treatment, it did not peel off from the stainless plate of the endless press machine, and the coating layer was destroyed when peeled off with a bare hand.

[Comparative Example 2] An ethylenically unsaturated monomer mixture having the same composition as in Example 1 was copolymerized in the same formulation as in Example 1 except that the aqueous neutralizing resin (A-6) was used as an emulsion stabilizer. The polymerization stability was poor and the desired aqueous dispersion could not be obtained.

[Comparative Example 3] With the same formulation as in Example 1, using an aqueous neutralizing resin (A-1) as an emulsion stabilizer, 20 parts of styrene, 45 parts of methyl methacrylate, and 35 parts of butyl methacrylate were used as ethylenic compounds. The saturated monomer mixture was copolymerized to obtain a milky white aqueous dispersion having a solid content of 40% and a viscosity of 450 cps.

The resulting dispersion has poor miscibility with alcohol,
Physical properties were not measured.

[Comparative Example 4] With the same formulation as in Example 1, using an aqueous neutralizing resin (A-1) as an emulsion stabilizer, 20 parts of styrene, 45 parts of methyl methacrylate, 30 parts of butyl methacrylate, glycidyl methacrylate. 5 parts of the ethylenically unsaturated monomer mixture was copolymerized to obtain a milky white aqueous dispersion having a solid content of 40% and a viscosity of 500 cps.

The obtained dispersion was subjected to the same press treatment as in Example 1.

[Comparative Example 5] With the same formulation as in Example 1, 50 parts of styrene, 31 parts of methyl methacrylate, and 17 parts of 2-ethylhexyl acrylate were prepared using the aqueous neutralizing resin (A-1) as an emulsion stabilizer.
Part, and a mixture of 2 parts of glycidyl methacrylate and an ethylenically unsaturated monomer were copolymerized to obtain a milky white aqueous dispersion having a solid content of 40% and a viscosity of 500 cps.

The obtained dispersion was subjected to the same press treatment as in Example 1.

Table 2 collectively shows types of neutralizing resins, monomer compositions and evaluation results in Examples 1 to 4 and Comparative Examples 1 to 6.

As is clear from Table 2, the use of the aqueous dispersion for press coat of the present invention is excellent in crushability, gloss, blocking resistance and alcohol miscibility.

On the other hand, when the neutralizing resin (A-5) having an acid value of 390 and outside the range of the present invention was used (Comparative Example 1), the blocking resistance was poor and the acid value was 40. When the neutralizing resin (A-6), which is low and outside the scope of the present invention, is used (Comparative Example 2), the effect of the neutralizing resin as an emulsion stabilizer is poor, the polymerization stability is poor, and the practicality is low. It is not possible to obtain a certain aqueous dispersion for press coating.

Further, as the ethylenically unsaturated monomer mixture (B),
When the one containing no glycidyl group-containing ethylenically unsaturated monomer was used (Comparative Example 3), the alcohol miscibility was poor,
It is not possible to obtain an aqueous varnish dispersion for press coat having sufficient performance. Furthermore, when the ethylenically unsaturated monomer mixture (B) containing more than 0.5% by weight of the glycidyl group-containing ethylenically unsaturated monomer is used (Comparative Example 4 to
5) It can be seen that the crushability and gloss are insufficient.

EFFECT OF THE INVENTION The present invention provides a dispersion liquid for a water-based varnish for a press coat, which has excellent alcohol miscibility, and has well-balanced crushability, gloss and blocking resistance.

Claims (2)

(57) [Claims] 1. An acid value of 50 obtained by copolymerizing an ethylenically unsaturated monomer mixture containing an ethylenically unsaturated carboxylic acid.
In the presence of the resin (A) obtained by neutralizing 300 to 300 resins, the glycidyl group-containing ethylenically unsaturated monomer is added to 0.05 to
Dispersion for aqueous varnish for press coat, which comprises an aqueous dispersion obtained by copolymerizing an ethylenically unsaturated monomer mixture (B) containing 0.5% by weight as a main component. 2. A water-based varnish for press coat according to claim 1, wherein the ratio of the neutralizing resin (A) to the ethylenically unsaturated monomer mixture (B) is in the range of 10/90 to 90/10. Dispersion.