JP3277262B2 - Paper coating resin and paper coating composition containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper coating resin which provides a coated paper having excellent printability and printing effect, and to the production of a coated paper using the same.

[0002]

2. Description of the Related Art In general, coated paper is produced by coating a pigment such as clay or calcium carbonate with a binder such as latex or starch. This coated paper is required to have higher printability as printing speeds, precision, and multi-color printing increase in recent years.

In order to improve the printability and the like, as resin for paper coating, for example, polyamide polyurea-formaldehyde resin such as Japanese Patent Publication No. 44-11667 and Japanese Patent Publication No. 59-32597, and Japanese Patent Publication No. 61-42931. Polyamide polyurea-epihalohydrin-formaldehyde resins have been proposed, but there is a problem that although the ink receptivity and the blister resistance are improved, the pick strength tends to be reduced.

On the other hand, Japanese Patent Publication No. 61-58599 discloses a coating composition containing a copolymer containing styrene and an ethylenically unsaturated carboxylic acid and a cationic organic compound.
JP-A-84599 discloses an acrylamide / acrylonitrile copolymer and JP-A-3-199492 discloses a copolymer containing an ethylenically unsaturated monomer and an amino group-containing vinyl monomer as main constituent monomers. It has been proposed to use as a resin for engineering, but when ink acceptance is increased,
While a decrease in pick strength, a decrease in printing gloss, a significant increase in viscosity of the paint, and the like occur, when the pick strength is increased, contradictory unfavorable properties such as a decrease in ink acceptability tend to appear, which is insufficient.

[0005]

As described above, although the conventional methods can improve the printing characteristics, they also have contradictory disadvantages. Therefore, the present invention improves the ink receptivity, pick strength, gloss in a well-balanced manner in recent years with high quality requirements for coated paper, and there is little change in the viscosity characteristics of the coating composition, or rather, it has a viscosity lowering effect. An object of the present invention is to provide a paper coating resin and a paper coating composition using the same.

[0006]

Means for Solving the Problems The present inventors have found that an addition condensate of an alkylenediamine or polyalkylenepolyamine with an acrylate or methacrylate, preferably a monoalkanolamine, a methacrylic acid, , Acrylic acid, methacrylic acid or amine salt or ammonium salt of acrylic acid or alkali metal salt, acrylamide, methacrylamide
When a reaction product obtained by condensing or adding more than one species is used as a paper coating resin, the ink receiving properties, pick strength, and gloss are improved in a well-balanced manner, and there is little change in the viscosity characteristics of the coating composition. The present inventors have found that the composition can be used as an industrial composition, and have completed the present invention.

That is, the paper coating resin according to the present invention is obtained by subjecting an alkylene diamine or polyalkylene polyamine to an addition condensation of an acrylate ester or a methacrylate ester so that the active hydrogen at the terminal amino group is reduced to 60 mol% or less. It is characterized by containing a product as a main component.

The alkylenediamine used in the present invention includes ethylene diamine, propylene diamine, butylene diamine and the like, and the polyalkylene polyamine includes diethylene triamine, triethylene tramine, tetraethylene pentamine, pentaethylene hexamine and the like. Ethylenediamine is preferred as alkylenediamine and diethylenetriamine and triethylenetetramine are preferred as polyalkylenepolyamine from the viewpoint of the viscosity of the ionic reactant.

The acrylate or methacrylate which reacts with the amines includes methyl acrylate, wherein the alkyl group in the ester portion has 1 to 3 carbon atoms.
Ethyl acrylate, propyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate are preferred. When the carbon number of the alkyl group in the ester portion exceeds 3, the reaction rate with the above amines is slow, and the boiling point of the by-product alcohol after the condensation reaction is high, so that the target product cannot be sufficiently distilled off from the reaction system. In this regard, methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate are particularly preferable as the acrylate or methacrylate.

The coating resin according to the present invention is a mere addition condensate of an alkylenediamine or a polyalkylenepolyamine with an acrylate or methacrylate, and a pigment having a large amount of primary and secondary amino groups remaining. When the composition is mixed with an aqueous binder to form a paper coating composition, the viscosity is excessively increased due to aggregation of the pigment, and the coating property is deteriorated. Therefore, the active hydrogen of the amino group of the terminal group of the addition condensate must be 60 mol% or less. Thus, by repeatedly performing the above addition condensation reaction, the number of moles of the remaining amino group can be adjusted.

More preferred coating resins include the above-mentioned addition condensation products having an ester group or an amino group at the end of the condensation reaction, as well as monoalkanolamines, methacrylic acid, acrylic acid, methacrylic acid or acrylic acid. And a reaction product obtained by condensing or adding at least one of an amine salt, an ammonium salt or an alkali metal salt, acrylamide and methacrylamide.
As a result, the reaction product becomes a highly branched polymer, and when used in paper coating, the balance between ink receptivity, pick strength, and gloss is further improved, and the viscosity characteristics of the paper coating composition also change. It becomes a resin for paper coating that can be reduced in amount or reduced in viscosity.

The addition condensation reaction between the alkylenediamine or the polyalkylenepolyamine and the acrylate or methacrylate can utilize a Michael addition reaction which is an addition reaction of an amine to an active double bond. That is, first, an acrylate or a methacrylate (hereinafter referred to as an acrylate) is added to an alkylenediamine or a polyalkylenepolyamine, and an addition reaction is performed at 40 to 90 ° C. At this time, the molar ratio of the amines to the acrylate ester is such that an acrylate ester or the like having a molar amount twice as much as the primary amino group contained in the amines and an equimolar amount of the secondary amino group is added. Subsequently, amines in the same molar amount as the added acrylate ester and the like are added, and the mixture is gradually heated to about 130 to 160 ° C. to distill off alcohol by-produced by condensation. At this time, the first-stage addition reaction and the first-stage condensation reaction can be simultaneously mixed and continuously performed. An acrylate ester or the like is again added in an amount corresponding to the number of moles of the remaining amine (twice the molar amount of the primary amino group and an equimolar amount of the secondary amino group), and the addition reaction is performed again at 40 to 90 ° C. By repeating addition and condensation in this manner, an addition condensation product having a desired molecular weight is obtained. The process can be terminated when a desired terminal group is obtained, or can be completed in a state where an acrylate or the like is partially or entirely added to the terminal group. For this purpose, active hydrogen at the terminal amino group is 60
The addition reaction is carried out so that the concentration is not more than
A molecular weight of about 2 times is preferable from the viewpoint of viscosity and performance.

In the subsequent reaction, the condensate of the monoalkanolamine is added to the addition condensation product up to the addition reaction of the acrylic acid ester or the like after the condensation with the addition of the monoalkanolamine and heated to about 150 ° C. to carry out the condensation reaction. And distilling off the alcohol. Additives such as methacrylic acid, acrylic acid, amine salts or ammonium salts of methacrylic acid or acrylic acid, alkali metal salts, acrylamide, methacrylamide, and the like are obtained by adding methacrylic acid An acid, acrylic acid, methacrylic acid or an amine salt or an ammonium salt of acrylic acid or an alkali metal salt, acrylamide, methacrylamide, or the like may be used alone, mixed or sequentially added, and reacted at 40 to 90 ° C.

The addition of methacrylic acid or acrylic acid is preferably carried out with an amine salt, an ammonium salt or an alkali metal salt from the viewpoint of preventing aggregation with an amine. Further, a terminal adduct such as an acrylate ester may be hydrolyzed with an alkali to form a terminal group of the carboxylate.

The reaction product thus obtained is neutralized with an acid such as sulfuric acid, hydrochloric acid, nitric acid or acetic acid, and diluted with water to obtain 4%.
It can be used as an aqueous solution having a concentration of 0 to 70%.

The coating resin according to the present invention is used as a composition by mixing with a pigment and an aqueous binder. Examples of the pigment include inorganic pigments such as calcium carbonate, kaolin, talc, satin white, aluminum hydroxide, and titanium oxide, and organic pigments such as polystyrene resin and urea-formaldehyde resin. Examples of the aqueous binder include water-soluble binders such as oxidized starch, phosphated starch, casein, polyvinyl alcohol, carboxymethyl cellulose, styrene-butadiene copolymer, carboxy-modified styrene-butadiene copolymer, vinyl acetate resin, and ethylene. -Vinyl acetate resin,
Emulsion binders such as acrylic resins can be used alone or in combination, and other dispersants, lubricants,
An antifoaming agent, a preservative, and the like are added, and mixed with the paper coating resin of the present invention to obtain a paper coating composition, which can be used for paper coating.

The mixing ratio of the paper coating composition of the present invention is 5 to 30 parts by weight of an aqueous binder with respect to 100 parts by weight of a pigment.
The paper coating resin of the present invention is preferably 0.05 to 1.0 part by weight. In addition, the paper coating resin of the present invention may be mixed in advance with an aqueous binder, and a water-based binder containing the paper coating resin of the present invention may be used to prepare a paper coating composition.

The paper coating composition of the present invention is coated on a paper substrate by a conventionally known method, and dried by a usual method.
If necessary, a super calender treatment or the like can be performed to obtain a coated paper.

[0019]

The coated paper using the paper coating resin of the present invention has excellent ink receptivity, especially wet wetness, and has a dry pick strength, which tends to occur with conventional resins.
It is suitable as a paper coating composition without a decrease in wet topic strength and an improvement in printability such as an improvement in print gloss, and a decrease in coatability due to an increase in color viscosity at high shearing force. .

[0020]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to the following examples. The following parts and% mean parts by weight and% by weight, respectively.

(Synthesis example of base addition condensation resin) Stirrer,
A reaction vessel equipped with a thermometer is charged with 137.8 parts of methyl acrylate. Add 24 parts of ethylenediamine with stirring and maintain at 80 ° C. for 1 hour, then add 96.2 parts of ethylenediamine, slowly heat to 140 ° C., maintain at 140 ° C. until methanol formed is distilled off, and terminate the amino group with amino. A group addition condensation resin A was obtained.

(Resin B) 103.2 parts of addition condensation resin A is charged into a reaction vessel and heated to 50 ° C. Separately, 34.6 parts of acrylic acid plus 73 parts of 25% caustic soda 95
Prepare an aqueous solution of 100% neutralized sodium acrylate. The aqueous sodium acrylate solution was slowly added to the reaction vessel with stirring, gradually heated, and maintained at 90 ° C. for 1 hour. After cooling, add 48 parts of ethyl acrylate and heat to 90 ° C.
Time kept. While cooling, 15% sulfuric acid was added to adjust the pH to 7, and the mixture was diluted with water to obtain a pale yellow transparent aqueous solution having a concentration of 50%.

(Resin C) A reaction vessel is charged with 51.7 parts of addition condensation resin A and heated to 50 ° C. 68.8 parts of methyl acrylate were added, heated to 80 ° C. and kept for 1 hour.
Then, 48.1 parts of ethylenediamine were added, and the mixture was slowly heated to 150 ° C. and kept at 150 ° C. until the formed methanol was distilled off. Separately, a 95% aqueous solution of neutralized sodium acrylate is prepared by adding 145.9 parts of 25% caustic soda to 69.1 parts of acrylic acid while cooling and stirring.
The aqueous sodium acrylate solution was slowly added to the reaction vessel with stirring, gradually heated, and maintained at 90 ° C. for 1 hour.
While cooling, 15% sulfuric acid was added to adjust the pH to 7, followed by dilution with water to obtain a 50% concentration pale yellow transparent aqueous solution.

(Resin D) 137.8 parts of methyl acrylate is charged into a reaction vessel. While stirring, 24 parts of ethylenediamine was added and the mixture was kept at 80 ° C. for 1 hour. Then, 48.1 parts of ethylenediamine and 48.9 parts of monoethanolamine were added, and the mixture was slowly heated to 140 ° C. to distill off methanol produced. After cooling to 50 ° C., 160 parts of ethyl acrylate was added, heated to 80 ° C., and kept at 160 ° C. until the produced ethanol was distilled off. 1 while cooling
The pH was adjusted to 7 by adding 5% sulfuric acid, and the mixture was diluted with water to obtain a pale yellow transparent aqueous solution having a concentration of 50%.

(Resin E) A reaction vessel is charged with 103.2 parts of methyl acrylate. While stirring, 29.2 parts of triethylenetetramine were added. Heated to 80 ° C. and held for 1 hour. Then, 72.1 parts of ethylenediamine was added, the mixture was slowly heated to 140 ° C., kept at 140 ° C. until the produced methanol was distilled off, and 256 parts of a 40% aqueous acrylamide solution was added. The mixture was heated to 90 ° C., kept for 1 hour and cooled. 72 parts of ethyl acrylate were added and heated to 90 ° C. for 1 hour. 15 while cooling
% Sulfuric acid was added to adjust the pH to 7 and diluted with water to obtain a 50% concentration pale yellow transparent aqueous solution.

(Resin F) A reaction vessel is charged with 80 parts of methyl methacrylate. Add 12 parts of ethylenediamine with stirring and keep at 80 ° C. for 1 hour, then add 48.1 parts of ethylenediamine and slowly heat to 140 ° C.
The produced methanol was distilled off. 40% of 142 parts after cooling
Aqueous acrylamide solution was added, heated to 90 ° C., kept for 1 hour and cooled. Separately to 46.1 parts of acrylic acid.
Prepare a 95% aqueous solution of neutralized sodium acrylate with 2 parts of 25% caustic soda. The aqueous sodium acrylate solution was slowly added to the reaction vessel with stirring, gradually heated, and maintained at 90 ° C. for 1 hour. While cooling, 15% sulfuric acid was added to adjust the pH to 7, and the mixture was diluted with water to obtain a pale yellow transparent aqueous solution having a concentration of 50%.

(Comparative resin G) A reaction vessel was charged with 51.7 parts of addition condensation resin A and heated to 50 ° C. 68.8 parts of methyl acrylate were added, heated to 80 ° C. and kept for 1 hour. Then, 48.1 parts of ethylenediamine were added, and the mixture was slowly heated to 140 ° C. and kept at 140 ° C. until methanol produced was distilled off. While cooling, 15% sulfuric acid was added to adjust the pH to 7, and the mixture was diluted with water to obtain a pale yellow transparent aqueous solution having a concentration of 40%.

(Comparative resin H) A reaction vessel was charged with 51.7 parts of addition condensation resin A and heated to 50 ° C. 68.8 parts of methyl acrylate were added, heated to 80 ° C. and kept for 1 hour. Then, 48.1 parts of ethylenediamine were added, and the mixture was slowly heated to 140 ° C. and kept at 140 ° C. until methanol produced was distilled off. After cooling, 56 parts of ethyl acrylate were added, and the mixture was heated to 90 ° C. and maintained for 1 hour. While cooling, 15% sulfuric acid was added to adjust the pH to 7, and the mixture was diluted with water to obtain a pale yellow transparent aqueous solution having a concentration of 45%.

(Examples 1 to 5) Resins B to F were respectively blended according to the following paint composition to obtain a paper coating composition. A coated paper was prepared using each paper coating composition by the following method, and a performance test was performed.

(Comparative Examples 1 and 2) A coated paper was prepared using the comparative resin H in the same manner as in the example, and a test was conducted in the same manner. Also,
A coated paper was prepared in the same manner as for a paper coating composition using no comparative resin, and a test was conducted. It should be noted that the viscosity of the paper coating composition for Comparative Resin G was extremely high and could not be applied.

The composition of the paper coating composition is as follows. That is, kaolin clay (ultra white 9
0): 70 parts, calcium carbonate (Carbital 90):
30 parts, dispersant (Aron T-40): 0.2 part, sodium hydroxide: 0.08 part, starch (MS-46)
00): 5 parts, SB latex: 10 parts, synthetic resin and comparative synthetic resin (as solid content): 0.5 part, water:
Add an appropriate amount so that the solid content becomes 60%.

The above-mentioned paper coating composition was coated on a base paper for coating so as to have a coating amount of 15 ± 0.5 g / m ² by a rod coater and dried by a hot air drier at 150 ° C. for 8 seconds. . The obtained coated paper was treated at 20 ° C. and 65% RH. H. , Was subjected to supercalendering twice at 50 ° C and a linear pressure of 140 kg / cm, and subjected to various tests.

Each test method is as follows. Paint viscosity: The paint solid content was 60%, and the viscosity immediately after dispersion at 25 ° C. was measured using a B-type viscometer with a rotor No. 3, at 60 rpm. Printing gloss: Offset ink was printed in a multicolored manner with an RI printer, and measured (60 ° C.) using a Murakami gloss meter. Overprints are printed in 15 seconds intervals. Dry strength: The state of picking when overcoated with an RI printer was evaluated by a five-point method. The higher the score, the better.
Wet strength: The state of picking in printing after absorbing water with a Molton roll using a RI printer was evaluated by a five-point method. Swimsuit meatness: After kneading 0.5 ml of ink with an RI printing machine, printing was performed by flowing water between rolls slightly separated from each other, and the print density was measured with a Macbeth densitometer. The higher the value, the higher the ink receiving density. Table 1 shows the test results.

[0034]

[Table 1]

Claims (4)

(57) [Claims] 1. An alkylene diamine or polyalkylene polyamine and an acrylate or methacrylate having a residual amino hydrogen content of 60 at the terminal amino group.
A paper coating resin whose main component is a product obtained by adding and condensing to less than mol%. 2. Monoalkanolamines, methacrylic acid, acrylic acid, methacrylic acid or the like are added to the remaining terminal ester group or amino group of the addition condensation product of alkylene diamine or polyalkylene polyamine with acrylic acid ester or methacrylic acid ester. A paper coating resin containing, as a main component, a reaction product obtained by reacting at least one of an amine salt, an ammonium salt or an alkali metal salt of acrylic acid, acrylamide and methacrylamide. 3. The addition condensation product according to claim 1, wherein the addition condensation product is an addition condensation product of ethylenediamine, diethylenetriamine or triethylenetetramine and an acrylate or methacrylate having an alkyl group in the ester portion having 1 to 3 carbon atoms. 3. The paper coating resin according to 1 or 2. 4. A paper coating comprising 5 to 30 parts by weight of an aqueous binder and 0.05 to 1.0 part by weight of the resin for paper coating according to claim 1 based on 100 parts by weight of the pigment. Composition.