JPS6269898A - Water soluble resin composition for paper coating - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water-soluble resin composition for coating paper such as printing paper.

[Conventional technology]

It is well known that printing paper is coated with resin paint in order to protect the printing surface and give gloss and waterproof properties to the printing paper. A method of applying press working is known.

As paints for paper coating, copolymers of vinyl unsaturated monomers such as vinyl chloride, vinyl acetate, and (meth)acrylic acid esters, and styrene-based aromatic monovinyl monomers have traditionally been used in combination with benzene, toluene, xylene, etc. aromatic solvents, acetone, methyl ethyl ketone,
Those dissolved in ketone solvents such as methyl isobutyl ketone and cyclohexane, ether alcohols such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, and mixtures of their esters are widely used.

However, as mentioned above, in the case where organic solvents are used as solvents, there are serious problems in terms of safety and health due to the flammability and toxicity of these organic solvents.

Therefore, there is a demand in this industry for the development of an excellent water-based paper coating paint that has performance comparable to the above-mentioned conventional solvent-based paints. A water-soluble resin composition for paper coating in which carboxyl groups are neutralized with a volatile base has been reported.

[Problem that the invention seeks to solve]

However, conventional water-based gloss paints dry more slowly than solvent-based paints, and the physical properties of the paint film are also inferior. Improvement was required in terms of physical properties of the coating film.

Incidentally, the brittleness and mold releasability of the coating film are physical properties required when performing hot press processing using a mirror-finished plate.

In the water-soluble resin composition for paper coating made by neutralizing the carboxyl groups of a vinyl monomer copolymer as described above with a volatile base, carboxyl groups are added to the monomer composition of the copolymer in order to increase its water dilutability. It is necessary to blend a large amount of the group-containing monomer, but on the other hand, if the blending ratio of the carboxyl group-containing monomer increases, it is inevitable that the coating film's blistering resistance and water resistance will decrease. In the water-soluble resin composition for paper coating,
The research subject is to successfully solve the conflicting physical property problems of the water solubility and water dilubility of the resin and the water resistance and blistering property of the coating film, and solving this problem will lead to expanded applications in hot press processing. It is.

The purpose of the present invention is to solve the problems of the prior art as described above, and to maintain good water solubility and water dilutability while improving gloss, swelling properties, mold releasability, 1-blocking resistance, water resistance, etc. An object of the present invention is to provide a water-soluble resin composition for paper coating that has improved physical properties of a coating film.

[Technical means to solve problems]

”-In order to achieve the eleventh objective, the present invention provides (A)
General formula % formula %) (wherein, X and Y are hydrogen or methyl group, n is 1 to 10
(in the formula, R1 is hydrogen or a methyl group, R2 is a methyl group or an ethyl group, and n is 4 to 10% by weight) 1-7.5% by weight (C) Methyl methacrylate 40-90% by weight (D) α,β-unsaturated/carboxylic acid containing acrylic acid and methacrylic acid acid
The carboxyl groups of the copolymer obtained by radical polymerization of a monomer mixture consisting of 5 to 12.5% by weight in an alcohol or a mixed solvent mainly composed of alcohols have a volatility of 11! A water-soluble resin composition for paper coating is selected which is neutralized with a group of:

In addition, an ffi ffi mixture compound consisting of the above components (A), CB), (C:) and ([1), and (E) 30% by weight or less of other radically polymerizable vinyl monomers are used in combination. Then, a more excellent water-soluble resin composition for paper coating can be obtained.

[Effect of II]

1-, component (A), i.e., the general formula %) (wherein X and Y are hydrogen or a methyl group, and n is 1 to IO
) is an integer of ), which increases the hydrophilicity of the resin, makes it easier to dilute with water, and prevents the necessary bubbling of the coating when it is coated on printed matter as a water-based paint and hot-pressed. It is necessary to impart properties such as durability, water resistance, and gloss, and one type thereof can be used alone or two or more types can be used in combination.

In addition, the blending amount of the component (A) is lOw9. %, if a large amount of acrylic acid, methacrylic acid, etc. of component (D) is blended, the solution will undergo intramolecular crosslinking, resulting in a gelation phenomenon and cannot be used as a paint stock solution. If a small amount of component (A) is added, gelation does not occur, but the wood-philicity of component (A) is no longer blocked by crosslinking, resulting in poor water resistance. On the other hand, if the amount of component (A) is less than 4% by weight, if a small amount of component (D) is added, the hydrophilicity will decrease, as well as water dilutability and gloss. If it is added, the crumbling properties and mold release properties will be reduced.

Next, component (B), that is, ffNa having a structure represented by the general formula % (wherein R1 is hydrogen or a methyl group, R2 is a methyl group or an ethyl group, and n is an integer from 4 to 25) For the body, increase the hydration power of the resin and apply it! 2. Prevention and deglazing properties are necessary to give properties, and 1 of them! ! can be used alone or in combination with two inserts -1-. In addition, if the blending amount of this component (B) exceeds 7.5% by weight, the water resistance and blocking resistance of coating +1!2 will decrease, and if it is less than 5% by weight, there will be insufficient protection. Chemical properties and anti-glare properties cannot be obtained.

In addition, component (C), methyl methacrylate, is necessary to impart gloss, anti-blocking properties, and mold release properties to the coating film, and when the blend h) is less than 40% by weight, the softening point of the resin This results in poor mold release during hot pressing, and the coating film lacks blocking resistance and gloss. On the other hand, if the amount of component (C) exceeds 90% by weight, the water dilutability of the resin and the adhesion of the coating film will decrease.

Furthermore, component (D), an α,β-unsaturated carboxylic acid containing acrylic acid and methacrylic acid, is necessary to make the resin water-soluble and to add adhesion to the coating film, and is necessary to maintain the required physical properties of the coating film. Although acrylic acid and methacrylic acid must be used together in order to obtain this component (D
) is less than 5% N%, the water dilutability of the resin and the adhesion of the coating film will be poor, and conversely, 1
2. ! If it exceeds 3.7gj5%, the coating film will have poor blistering resistance and water resistance.

In addition, other radically polymerizable vinyl monomers of component (E) are used to improve adhesion and scratch resistance to the coating film.
It is used as appropriate to impart water-based properties, and if the compounding needle exceeds 30% by weight, blocking resistance, mold release properties, and crushing properties will be poor. As such component (E),
For example, (meth)acrylic acid alkyl esters such as ethyl (meth)acrylate, butyl (meth)acrylate, and propyl (meth)acrylate, unsaturated nitrites such as (meth)acrylonitrile, (meth)acrylamide, etc. unsaturated amides, styrene, vinyltoluene, etc.

Copolymers consisting of the various monomer components listed above can be made water-soluble by neutralizing their carboxyl groups with volatile bases such as ammonia, dimethylethanolamine, morpholine, methylmorpholine, and 2-amino-2-methylpropanol. It is preferable to prepare the product by diluting it with water to give a solid content of preferably about 20 to 30% by weight. In addition, various additives and auxiliary agents may be added as necessary during the preparation. It's okay. For example, as is well known, nonionic or anionic surfactants and silicone oil may be added to facilitate mold release during hot pressing.
Nonionic or anionic surfactants, waxes, etc. may also be added to improve the abrasion resistance and blocking resistance.

The water-soluble resin composition for paper coating according to the present invention is coated on printing paper using a roll coater, gravure cylinder, etc., dried using an infrared heater, hot air dryer, etc., and then subjected to hot press processing.

〔Example〕

Next, the present invention will be specifically explained based on Examples, but the present invention is not limited to these Examples. Note that parts and percentages in the following Examples and Comparative Examples are Heavy unless you do! There are 4 criteria.

Example 1 150 parts of isopropyl alcohol was charged into a polymerization apparatus equipped with a stirrer, a thermometer, a reflux condenser with a dropping funnel, and a nitrogen gas inlet tube, nitrogen gas was bubbled through, and the mixture was heated to 90°C while stirring. A monomer mixture with the following composition is added to
Dropped in 3 hours, and then added at the same temperature 3 times every hour.
．． Add 5 parts of 7zobisisobutyronitrile dispersed in 5 parts of isopropyl alcohol.

Polymerization was completed at a reaction temperature of 90° C. and a total reaction time of 8 hours.

<Monomer mixture> After the completion of the above polymerization, cool and add 8.5 parts of 25% ammonia wood dissolved in 41.5 parts of water at 40 ° C.
A water-soluble acrylic resin composition with a neutralization rate of 100 mol% and a solid content of 40% was obtained. Next, when the water-soluble acrylic resin composition was diluted with water to a solid content of 25%, it was easily dissolved.
A clear paint solution was obtained.

The coating solution was applied to an offset printing test paper using a roll coater equipped with an infrared heater, and a press temperature of 110℃ and a press pressure of 25℃ was applied using a Matsumoto endless press.
0Kg/c+? When hot pressing was carried out at a press speed of 20 m/win, the mold release properties during hot pressing were good, and the resulting processed paper had excellent coating film gloss, blistering, adhesion, blocking resistance, and water resistance. She had excellent sex.

Comparative Example 1 Monomer mixture> Isopropyl alcohol was added to the same polymerization apparatus as in Example 1.
Add 150 parts, aerate nitrogen gas, and add 9 parts while stirring.
A monomer mixture having the above composition was added dropwise to a solution heated to 0°C, and polymerization was carried out in the same manner as in Example 1. After cooling, 8.5 parts of 25% ammonia water was added to 41.5 parts of water. A water-soluble acrylic resin composition with a neutralization rate of 100 mol% and a solid content of 40% was obtained.6 Next, the water-soluble acrylic resin composition was diluted with water to a solid content of 25%. It became cloudy and insolubilized and could not be made into a paint.

Therefore, a water-soluble acrylic resin composition with a solid content of 40% was diluted with isopropyl alcohol to a solid content of 25% to make a coating solution, and the solution was applied to an offset printing test paper under the same conditions as in Example 1 and hot When press working was carried out, the mold releasability during hot pressing was good, but the resulting processed paper had poor coating film gloss and adhesion, making it unusable.

Example 2 <Medium 111 mixture> Isopropyl alcohol was added to the same polymerization apparatus as in Example 1.
Add 150 parts, aerate nitrogen gas, and stir while stirring.
A monomer mixture having the above composition was added dropwise to a mixture heated to 90°C, polymerization was carried out in the same manner as in Example 1, and then,
Cool and add 19.3 parts of 25% ammonia water dissolved in 30.7 parts of water to create a water-soluble acrylic resin with a neutralization rate of 90 mol% and a solid content of 40%! Next, when the water-soluble acrylic resin composition was diluted with water to a solid content of 25%, it was easily dissolved and a transparent coating solution was obtained.

When the coating solution was applied to offset printing test paper under the same conditions as in Example 1 and hot-pressed, the mold release properties during hot-pressing were good, and the resulting processed paper showed no coating film. It had excellent gloss, blistering properties, adhesion, blocking resistance, and water resistance.

Comparative Example 2 <Monomer mixture> In the same polymerization apparatus as in Example 1, 1 part of isopropyl alcohol was added.
Add 50 parts, aerate nitrogen gas, and add 90 parts while stirring.
A monomer mixture having the above composition was dropped into a mixture heated to ℃,
Polymerization was carried out in the same manner as in Example 1, and then cooled and 18.3 parts of 25% ammonia water dissolved in 30.7 parts of wood was added to give a neutralization rate of 90 mol% and a solid content of 40%. A water-soluble acrylic resin composition was obtained.Next, the water-soluble acrylic resin composition was diluted with water to a solid content of 25%, and was easily dissolved to obtain a transparent coating solution.

When the coating solution was applied to offset printing test paper under the same conditions as in Example 1 and hot press processing was performed, the mold releasability during hot pressing was good, but the resulting processed paper It had poor blistering resistance, blocking resistance, and water resistance, and was unusable.

Comparative Example 3 Width:, :L compound> Isopropyl alcohol was added to the same polymerization apparatus as in Example 1.
Add 150 parts, aerate nitrogen gas, and add 9 parts while stirring.
A monomer mixture having the above composition was added dropwise to a solution heated to 0°C, and polymerization was carried out in the same manner as in Example 1. After cooling, 19.3 parts of 25% aqueous ammonia was added to 30.7 parts of water. Then, the water-soluble acrylic resin composition was diluted with water to a solid content of 25%. A clear coating solution was obtained which dissolved easily.

When the coating solution was applied to offset printing test paper under the same conditions as in Example 1 and hot pressing was performed, the mold releasability during hot pressing was good, but the resulting processed paper did not have a coating film. The crushing resistance, blocking resistance and water resistance of the film were poor, making it unusable.

Example 3 <Soul 111 compound> Isopropyl alcohol was added to the same polymerization apparatus as in Example 1.
Add 150 parts, aerate nitrogen gas, and add 9 parts while stirring.
A monomer mixture having the above composition was added dropwise into a solution heated to 0°C, and polymerization was carried out in the same manner as in Example 1. After cooling, 16.7 parts of 25% ammonia water was added to 33.3 parts of water. il
It was dissolved in l'II and added to obtain a water-soluble acrylic resin composition with a neutralization rate of 100 mol% and a solid content of 40%. Then,
When the water-soluble acrylic resin M1 composition was diluted with water to a solid content of 25%, it was easily dissolved and a transparent coating solution was obtained.

When the coating solution was applied to offset printing test paper under the same conditions as in Example 1 and hot-pressed, the mold release properties during hot-pressing were good, and the resulting processed paper had a glossy coating. , it had excellent tear resistance, adhesion, blocking resistance, and water resistance.

Example 4 <Monomer mixture> 2-hydroxyethyl methacrylate 6 parts 2-hydroxypropyl acrylate 6 parts ethoxypolyethylene glycol methacrylate (
n=8)
4 parts Methyl methacrylate
146 parts A polymerization apparatus similar to Example 1 was charged with 100 parts of isopropyl alcohol, 50 parts of ethyl alcohol, and 173 of the monomer mixture having the above composition, and while nitrogen gas was bubbled through and the mixture was heated to 90°C with stirring. The remaining 2/3 of the monomer mixture having the above composition was added dropwise to the solution, polymerization was carried out in the same manner as in Example 1, and then the mixture was cooled to 25
15.2 parts of aqueous ammonia was dissolved in 34.8 parts of water and added to obtain a water-soluble acrylic resin composition with a neutralization rate of 90 mol% and a solid content of 40%.Next, the water-soluble acrylic resin composition When the product was diluted with water to a solids content of 25%, it dissolved easily and a clear coating solution was obtained.

The coating solution was applied to a offset printing test paper under the same conditions as in Example 1, and hot press pressure was applied. It had excellent gloss, blistering properties, adhesion, blocking resistance, and water resistance.

Example 5 <Monomer mixture> Isopropyl alcohol was added to the same polymerization apparatus as in Example 1.
130M and ethylene glycol monobutyl ether 20
A monomer mixture having the above composition was added dropwise to the mixture, which was heated to 90°C while bubbling with nitrogen gas and stirring, and polymerization was carried out in the same manner as in Example 1, followed by cooling. 2
10.1 parts of 5% ammonia water was dissolved in 39.9 parts of water and added to obtain a water-soluble acrylic resin composition with a neutralization rate of 90 mol% and a solid content of 40%.Next, the water-soluble acrylic resin When the composition was diluted with water to a solids content of 25%, it dissolved easily and a clear coating solution was obtained.

When the coating solution was applied to offset printing test paper under the same conditions as in Example 1 and hot press was applied, the mold releasability during hot pressing was good, and the resulting processed paper had a good coating film. It had excellent gloss, glossiness, adhesion, blocking resistance, and water resistance.

Example 6 <Qi polymer mixture> In the same polymerization apparatus as in Example 1, 1 part of isopropyl alcohol was added.
Add 50 parts, aerate nitrogen gas, and add 90 parts while stirring.
A monomer mixture having the above composition was dropped into a mixture heated to ℃,
Polymerization was carried out in the same manner as in Example 1, and then cooled and 11.2 parts of 25% ammonia water dissolved in 38.8 parts of water was added to give a neutralization rate of 90 mol% and a solid content of 40%. A Water-Soluble Acrylic Resin Ml Composition Was Obtained Next, when the water-soluble acrylic resin composition was diluted with water to a solid content of 25%, it was easily dissolved and a transparent coating solution was obtained.

When the coating solution was applied to offset printing test paper under the same conditions as in Example 1 and hot-pressed, the mold release properties during hot-pressing were good, and the resulting processed paper had a glossy coating. , excellent tackiness, adhesion, blocking resistance, and water resistance.

Comparison of physical properties of water-soluble resin compositions Table 1 shows the results of comparing the physical properties of the water-soluble resin compositions for paper coating according to Examples 1 to 6 and Comparative Examples 1 to 3 for each item.

(Hereinafter referred to as the following blank) Table 1 Comparison of physical properties of water-soluble resin compositions) Measurement method of physical properties (a) Measured by gloss meter (60° gloss meter of Suga Test Instruments) (b) Adhesion: by cellophane tape Of the paint film! Determine the peeling state (O: no peeling at all, O: almost no peeling, Δ
: There is peeling.

×・Completely peeled off) (C) Scratchability: Judging the state of scratching of the coating film by microspertil (o: No change at all, O: Almost no change, Δ: Peeling, X: Completely peeled off) (d ) Water resistance: Condition of the coating film when rubbed 200 times with hydrated absorbent cotton (o: no change, O: almost no change, Δ: swelling, x: swelling and dissolution) (e) R type Properties: Determine the state of release from the specular plate during hot pressing (o: completely separated by 21, ○: almost completely peeled off, Δ: fused, ×: completely fused) ('') Bubble resistance: The surface condition of the film was visually judged (O: completely good).

0: Good, Δ: Slightly poor, ×: Poor) (g) Blocking resistance = 55°C, 90%RH 1250g / C1
l? Judging the state of fusion between the coated film surfaces after 24 hours of treatment (■: no fusion at all, O: almost no fusion, Δ: fusion, ×: completely fusion) (hereinafter referred to as quince margin) [Invention] [Effects] As described above, the water-soluble resin composition for paper coating according to the present invention has good water solubility and water dilutability necessary for forming into a paint, and also has gloss.

It is possible to provide a coating film with excellent physical properties in terms of crumbling properties, mold releasability, blocking resistance, water resistance, etc.

that's all

Claims (1)

[Claims] 1. (A) A structure represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X and Y are hydrogen or a methyl group, and n is an integer from 1 to 10) 4 to 10% by weight of monomer (B) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 is hydrogen or methyl group, R_2 is methyl group or ethyl group, n is an integer from 4 to 25 (C) Methyl methacrylate 40-90% by weight (D) 5-12 α,β-unsaturated carboxylic acids including acrylic acid and methacrylic acid Water for paper coating made by neutralizing the carboxyl groups of a copolymer obtained by radical polymerization of a monomer mixture consisting of .5% by weight in an alcohol or a mixed solvent mainly consisting of alcohols with a volatile base. Soluble resin composition. 2. (A) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, X and Y are hydrogen or methyl groups, and n is an integer from 1 to 10) Monomer 4 ~ 10% by weight (B) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 is hydrogen or methyl group, R_2 is methyl group or ethyl group, n is an integer from 4 to 25) 1-7.5% by weight of structural monomers (C) 40-90% by weight of methyl methacrylate (D) 5-12.5% by weight of α,β-unsaturated carboxylic acids including acrylic acid and methacrylic acid (E ) Other radically polymerizable vinyl monomers 3
Water for paper coating made by neutralizing the carboxyl groups of a copolymer obtained by radical polymerization of a monomer mixture consisting of 0% by weight or less in an alcohol or a mixed solvent mainly composed of alcohols with a volatile base. Soluble resin composition.