JPS62125093A - Paper coating composition - 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 <Industrial Application Field> The present invention relates to a paper coating composition that provides coated paper with excellent printability and printing effects.

<Conventional technology> Coated paper, which is obtained by coating paper with a paper coating composition mainly consisting of pigments and an aqueous binder and performing necessary processes such as drying and calendering, is known for its excellent properties. Coated paper is widely used in commercial printed matter, magazines, books, etc. due to its printing effects and other features, but as quality requirements become more sophisticated and printing speeds increase, efforts are being made to improve the quality of coated paper. Particularly in offset printing, which accounts for the majority of printing, improving and improving ink receptivity under the impression of dampening water, water resistance in wet picks and wet rubs, and blister resistance in rotary printing are important issues for the industry. be.

Conventionally, to solve these problems, melamine-formaldehyde resin, urea-formaldehyde resin, polyamide polyurea-formaldehyde resin, polyamide polyurea-formaldehyde-epihalohydrin resin, such as Japanese Patent Publication No. 44-11667, Japanese Patent Publication No. 59-32597,
A method is known in which a waterproofing agent or the like is added as disclosed in Japanese Patent Application Laid-Open No. 58-40322, etc., in an attempt to solve the problem.

<Problems to be Solved by the Invention> However, while all of the conventionally used water-resisting agents have effective properties, they have serious drawbacks and are therefore unsatisfactory in practice.

For example, aminoblast resins such as melamine-formaldehyde resin and urea-formaldehyde resin not only generate a lot of formaldehyde during operation and from coated paper, but also have little effect on improving ink receptivity or blister resistance. Furthermore, it becomes extremely difficult to obtain a water-resistant effect as the pH of the coating composition increases. Furthermore, polyamide polyurea-formaldehyde resin is effective in improving water resistance as well as ink receptivity and blister resistance, but the degree of improvement is still insufficient in response to recent demands for higher quality coated paper. This is sufficient, and there is a demand for even higher performance. The purpose of the present invention is to meet such demands by using a paper coating composition containing a specific resin to provide coated paper with high water resistance, ink receptivity, etc. that could not be obtained with conventional techniques. There is a particular thing.

<Means for solving the problem> As a result of intensive studies by the present inventors in order to obtain a paper coating composition that imparts high water resistance, ink receptivity, etc. to coated paper,
(I) pigment, (II) aqueous binder and (III) (a) polyalkylene polyamine (b) obtained by reaction of alicyclic dibasic carboxylic acid and/or alicyclic dibasic carboxylic acid with glycols. reaction product with free carboxyl groups.

A paper coating composition containing a resin reacted with (c) ureas, (d) an alkylating agent, and optionally (e) formaldehyde and/or glyoxal is extremely effective in improving the desired performance of coated paper. They found that it is effective and completed the present invention. The present invention relates to the above-mentioned resin (I[[
), and furthermore, a reaction between the alicyclic dibasic carboxylic acid and/or the alicyclic carboxylic acid and glycols as the reaction component (b) to form the (III). It is characterized by the use of a reaction product having free carboxyl groups obtained in .

The content of the present invention will be explained in further detail.

The (a) polyalkylene polyamine used in the production of the resin (■[) used in the present invention has 2
A compound having at least one primary amino group and at least one secondary amino group, specifically, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, 3-azahexane-1,6-diamine. , 4,7-thiazadecane-1,1
Examples include 0-diamine. These polyalkylene polyamines can be used not only alone but also as a mixture of two or more. Furthermore, there is no hindrance to the use of aliphatic diamines such as ethylene diamine and propylene diamine in combination with the above-mentioned polyalkylene polyamines within the range that does not impede the object of the present invention.

Next, (b) alicyclic dibasic carboxylic acid is a general term that includes compounds having two carboxyl groups in the molecule, their esters, and their acid anhydrides, Representative examples of such dibasic carboxylic acids include the following.

Carboxylic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexane-1,4-dicarboxylic acid, 4-methyltetrahydrophthalic acid, and their esters, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4- These are acid anhydrides such as methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, Δ4-tetrahydrophthalic anhydride, and 4-methylΔ4-tetrahydrophthalic anhydride.

These may be used alone or in combination of two or more.
Furthermore, in addition to these dibasic carboxylic acids, other dibasic carboxylic acids such as aliphatic dicarboxylic acids such as adipic acid and glutaric acid, or aromatic dicarboxylic acids such as terephthalic acid and phthalic acid may be used as long as the effects of the present invention are not impaired. It may be used in combination with an acid.

In addition, the glycols include alkylene glycols such as ethylene glycol, propylene glycol, and butanediol, cycloalkylene glycols such as butynediol, cyclobentanediol, and cyclohexanediol, alkenylene glycols containing octenediol, diethylene glycol, and dipropylene glycol. ,
Polyalkylene glycol IJ such as triethylene glycol, polyethylene glycol, polytetramethylene glycol, etc.
Examples include coal neck, ethylene oxide adduct of bisphenol A, and ethylene oxide adduct of hydrogenated bisphenol A.

Furthermore, as a reaction product having a free carboxyl group obtained by the reaction of an alicyclic dibasic carboxylic acid and a glycol, the alicyclic dibasic carboxylic acid and the glycol are combined with an excess molar amount of carboxylic acid. It is a polyester having a carboxyl group at the end of the molecule, which is obtained by reacting at a specific temperature. The reaction between this alicyclic dibasic carboxylic acid and glycols is usually carried out at 80 to 200°C in the presence or absence of a catalyst.
This is done by heating for 30 minutes to 2 hours.

Further, (c) ureas include urea, thiourea, guanyl raw material, methylurea, dimethylurea, etc., but urea is preferred from an industrial standpoint.

Furthermore, the following various alkylating agents can be used as component (d).

(1) A halogen-containing compound represented by the general formula R, -X (wherein R2 represents a lower alkyl group, alkenyl group, benzyl group, or phenoxyethyl group, and X represents a halogen atom). Preferred examples include the bromides and iodides corresponding to methyl chloride, ethyl chloride, propyl chloride, allyl chloride, benzyl chloride, phenoxyethyl chloride and the 2-isochloride.

(2) Dialkyl sulfides and dialkyl sulfates represented by the general formula (R20)2SOv (wherein R2 represents a lower alkyl group, and V represents 1 or 2).

Preferred examples include dimethyl sulfate, diethyl sulfate, dimethyl sulfide, diethyl sulfide and the like.

(3) General formula [In the formula, R3 represents a hydrogen atom, a lower alkyl group, a hydroxyalkyl group, or a phenyl group. ] Ethylene oxide derivative. Preferred examples include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, glycidol, and the like.

(4) General formula [wherein X represents a halogen atom, and W represents 1.2 or 3]. ] Epihalohydrin represented by . Preferred examples include epichlorohydrin and epibromohydrin.

(5) General formula HOCH2 (cH2). X (in the formula X and W
is the same as above. ) Monohalohydrin. Preferred examples include ethylene chlorohydrin and ethylene bromohydrin.

(6) General formula [wherein X is the same as above, Y is a halogen atom or an OH group,
and Z represents an OH group when the above Y is a halogen atom, and a halogen atom when the above Y is 0) (a group).A preferable example is 1.3
-dichloro-2-propatur, 2,3-dichloro-1
- Examples include property tools. Among the above, particularly preferred is epichlorohydrin.

The compounds used as the alkylating agent may be used alone or in combination of two or more.

The resin obtained by the method of the present invention is obtained in the form of an aqueous solution, and is usually prepared at a temperature of 50% by weight at 25°C.
Those with a viscosity of 5 to 1000 centipoise (hereinafter abbreviated as cp), and those with extremely low viscosity tend to have a low effect of adding resin as a coating composition for paper, and those with high viscosity is practically 10 to 500 cp, since the viscosity of the prepared paper coating composition may be high, which is generally associated with undesirable drawbacks.

Particularly preferably, those having a viscosity in the range of 20 to 200 cp are preferably used.

Next, each component (a), (b), (c), (d) and (e)
The reaction method is described below. The resins of the invention can be prepared, for example, by reacting the reaction products of components (a), (b) and (c) with (d) and, if desired, (e). The components (a), (b) and (c) can be reacted in any order.

First of all, components (a) and (b) can be reacted and then component (c) can be reacted. Components (a) and (b)
The reaction is carried out at a temperature of 120-250°C, preferably 130-250°C.
2 to 12 hours at 200℃ while removing the generated water from the system.
done in time. The amount of carboxyl group in component (b) is 0.1 mole per mole of polyalkylene polyamine of component (a).
The reaction is carried out at a ratio of 4 to 4 equivalents, preferably 0.8 to 3 equivalents. The dehydration condensation reaction product thus obtained,
The reaction of component (c) with ureas is carried out at a temperature of 100 to 180°C.
Preferably, the reaction is carried out at 110 to 160° C. for 1 to 6 hours while removing generated ammonia from the system. The amount of component (c) to be used is 1 equivalent or less, preferably 0.1 equivalent to 1 equivalent of amine groups, that is, primary and secondary amino groups in component (a).
It is 1 to 0.8 equivalent.

Alternatively, components (a) and (c) are first reacted,
Component (b) can then be reacted, and then component (c) can be reacted. For 1 mole of component (a), component (
c) is used in an amount of 0.2 to 1 mol, preferably 0.3 to 0.8 mol, and the temperature is 100 to 180°C, preferably 110 to 1 mol.
The deammoniation reaction is carried out at 60° C. for 1 to 6 hours.

The reaction product thus obtained and component (b) are reacted at a temperature of 120 to 250°C, preferably 130 to 20°C.
The reaction is carried out at 0° C. for 2 to 12 hours while removing generated water from the system. Component (b) is, for 1 mole of component (a),
It is used in an amount of 0.2 to 2 equivalents, preferably 0.3 to 1.8 equivalents. Components (a) and (b) thus obtained
The step of reacting the reaction products of ) and (c) with component (c) again is carried out at a temperature of 100 to 180°C, preferably 1
It is carried out at 10-160°C for 1-6 hours. The amount of component (c) used is 2 to 1 secondary amino group in component (a).
The amount is less than equivalent, preferably in the range of 0.1 to 1.5 equivalents.

Yet another method is to react components (a), (b) and (c) simultaneously, and further add component (c) to the resulting reaction product.
It is also possible to react. First component (a), (b)
The reaction (c) is carried out at a temperature of 100 to 200°C, preferably 110 to 180°C, for 2 to 12 hours while removing generated ammonia and water from the system. The ratio of each component used in this step is 1 mole of component (a) to 1 mole of component (b).
) carboxyl group of 0.2 to 2, preferably 0.3
~1.8 equivalents, 0.2 to 1 mol, preferably 0.3 to 0.8 mol of component (c) are suitable. The step of further reacting the reaction product thus obtained with component (c) is as follows:
It is carried out at a temperature of 100 to 180°C, preferably 110 to 160°C, for 1 to 6 hours. The amount of component (c) used is
2 equivalents or less, preferably 0.1 to 1.5 equivalents, per equivalent of the secondary amino group of ).

Components (a) and (b) obtained by various methods as above
The reaction products of (c) and (c) are both dissolved in water and then reacted with the alkylating agent (d) and, if desired, formaldehyde and/or glyoxal (e). The reaction with the alkylating agent is carried out in an aqueous solution with a concentration of 20-80% by weight, preferably 30-70% by weight, p)
3 to 12, and the reaction temperature is 20 to 80°C for 1 to 10 hours. The amount of alkylating agent to be used is 2 equivalents or less, preferably 0 equivalent to 1 equivalent of secondary amino group in component (a).
．． A range of 1 to 1.5 equivalents is suitable.

In the present invention, component (e) can be reacted if desired. The reaction products of components (a), (b) and (c) and components (d) and (e) may be reacted in any order,
The object of the present invention can be achieved by any of the following methods: reaction (d) followed by reaction (e), reaction (e) followed by reaction (d), or simultaneous reactions (d) and (e). The reaction of component (e) takes place at a concentration of 2
The reaction is carried out in an aqueous solution of 0 to 80%, preferably 30 to 70%, at a reaction temperature of 20 to 80°C for 1 to 10 hours.

The amount of (e) used is 1 mol or less per 1 mol of (c),
Preferably, 0.1 to 0.8 mol is appropriate. reaction pH
When glyoxal is used, the pH is preferably 5 to 8, and when formaldehyde is used, the pH is preferably 3 to 7.

After the reaction is completed, the resin used in the present invention is obtained by adjusting the pH to 4 to 8 with an alkali such as caustic soda or potassium hydroxide, or an acid such as hydrochloric acid, sulfuric acid, or formic acid, if necessary.

In addition, the pigment (I) in the present invention includes white inorganic pigments such as kaolin, talc, calcium carbonate (heavy and light), aluminum hydroxide, satin white, and titanium oxide, as well as polystyrene, melamine-formaldehyde resin, and urea-formaldehyde resin. White organic synthetic pigments such as these can be used alone or in combination of two or more. Alternatively, colored inorganic or organic pigments can also be used in combination.

The (II) water-based binder in the present invention includes water-soluble binders such as oxidized starch, phosphate esterified starch, polyvinyl alcohol, casein, gelatin, and carboxymethyl cellulose, styrene-butadiene resin, vinyl acetate resin, and ethylene-vinyl acetate resin. resin,
Water emulsion type binders such as methyl methacrylate-butadiene type resins can be used alone or in combination of two or more types.

The composition ratio of the paper coating composition of the present invention is (I) pigment 1
00 parts by weight, (II) aqueous binder 1 to 5
0 parts by weight, preferably 6 to 40 parts by weight, and (III) resin 0.05 to 10 parts by weight, preferably 0.1 to 3 parts by weight. Moreover, the solid content concentration of the coating composition is 20 to 75% by weight.

Generally, the resin (I) used in the present invention is added to and mixed with a pigment and an aqueous binder when preparing a paper coating composition.
The effects of the present invention can also be obtained by adding and mixing the pigment slurry and/or the aqueous binder in advance.

The paper coating composition of the present invention requires other components such as a dispersant, a viscosity/flow modifier, an antifoaming agent, a preservative, a lubricant, a water retention agent, and a coloring agent such as a dye or a colored pigment. It can be blended accordingly.

In addition, in the process of creating the coating composition of the present invention, the order of blending each component is not particularly limited, but due to differences in ionicity, etc., the dispersion stability as a composition may be reduced. The order of blending, the solids concentration of each component at the time of blending, the pH of the coating composition, etc. should be selected to avoid
It is desirable to implement this.

The paper coating composition of the present invention can be applied to a paper substrate by a conventionally known method, such as a blade coater, an air knife coater, a roll coater, a size press coater, a Kate roll coater, or a cast coater. A coated paper can be produced by coating the paper on top, performing necessary drying using a conventional method, and further performing a supercalender treatment if necessary.

<Effects of the Invention> The coated paper thus obtained using the paper coating composition of the present invention has excellent ink receptivity, water resistance, improved gloss, improved opacity, and blister resistance, and is free from formaldehyde. It has various excellent and effective properties such as no odor.

In addition, "paper" in the paper coating composition in the present invention has a broad meaning and includes paper and paperboard in a narrow sense.

<Examples> The present invention will be explained in more detail below using reference examples and examples. Both % and parts in the text represent weight percentages and parts by weight.

Reference Example-1 [Synthesis of resin (m)] 58.5 parts (0.4 mol) of triethylenetetramine was placed in a four-way flask equipped with a thermometer, reflux condenser, and stirring bar.
and 12.0 parts (0.2 mol) of urea, and the internal temperature was 120 ~
The mixture was heated at 140° C. for 3 hours to perform a deammonia reaction.

Thereafter, 34.4 parts (0.2 mol) of hexahydrophthalic acid was added, and a dehydration and amidation reaction was carried out at an internal temperature of 150 to 160° C. for 5 hours.

Thereafter, the internal temperature was cooled to 130°C, and 4 g of urea, 0 parts (
0.8 mol) was charged and the deammoniation reaction was carried out at a temperature of 120 to 130°C for 2 hours. Thereafter, it was cooled to 100°C and water was added to make a 50% aqueous solution.

Then, 18.5 parts (0.2 mol) of epichlorohydrin
was charged and reacted at 60°C for 4 hours. Thereafter, it was cooled to 25° C., the pH was adjusted to 7 with 35% hydrochloric acid, and water was added to obtain a resin liquid with a concentration of 50% and a viscosity of 52 cp (25° C.). This is called resin liquid A.

Reference Example-2 Triethylenetetramine 29 was placed in the same container as Reference Example-1.
．． 2 parts (0.2 mol) were charged, and 30.8 parts (0.2 mol) of hexahydrophthalic anhydride was added thereto, the temperature was raised, and dehydration and amidation were performed at 150 to 155°C. The mixture was then cooled to 130°C, 12 parts (0.2 mol) of urea was charged, and ammonia removal reaction was carried out at 125-130°C for 2 hours. Next, this was cooled to 60°C and diluted with water to make a 50% aqueous solution.

Next, 18.5 m (0.2 t=L) of epichlorohydrin and 15.4 parts (0.1 mol) of diethyl sulfate were charged.
The reaction was carried out at 60°C for 7 hours. Then cool to 25℃,
Adjust the pH to 6 with 20% sulfuric acid and add water to a concentration of 50.
%, and a viscosity of 63 cp (25°C) was obtained. This is called resin liquid B.

Reference Example-3 Triethylenetetramine 58 in the same container as Reference Example-1
, 5 parts (0.4 mol) and 30.4 parts (0.2 mol) of tetrahydrophthalic anhydride, and 12 parts (0.2 mol) of urea were simultaneously charged and heated to 150 to 155°C for 5 hours to dehydrate the amide. oxidation and deammonification reactions were performed simultaneously. Next, the mixture was cooled to 130°C, 12 parts (0.2 mol) of urea was added, and ammonia removal reaction was carried out at 125-130°C for 2 hours. This was diluted by adding water to obtain an aqueous solution with a concentration of 50%.

Next, 23.2 parts (0.4 mol) of propylene oxide was charged and reacted at 25°C for 6 hours. Next, 9.3 parts (0.1 mol) of epichlorohydrin was charged, and the mixture was heated at 60°C for 3
After reacting for an hour, it was cooled to 30°C, the pH was adjusted to 6 with 35% hydrochloric acid, and water was added to give a concentration of 50% and a viscosity of 55%.
A resin liquid of cp (25°C) was obtained. This is called resin liquid C.

Reference Example-4 Triethylenetetramine 58 in the same container as Reference Example-1
．． 5 parts (0.4 mol) and 12 parts (0.2 mol) of urea were charged in total, and the deammonia reaction was carried out at 145 to 150°C for 4 hours. In another container, add 60% of tetrahydrophthalic anhydride.
．． 8 parts (0.4 mol) and 15.2 parts of propylene glycol
N (0.2 mol) was mixed and heated at 140 to 150°C for 2 hours to obtain a polyester. The entire amount of this polyester was charged into a container that had undergone the above-described deammonization reaction, and heated at an internal temperature of 150 to 155° C. for 4 hours to perform dehydration and deammonia reaction. The mixture was then cooled to 130°C, 12 parts (0.2 mol) of urea was added, and ammonia removal reaction was carried out at 125-130°C for 2 hours. The drained water was added to make a 50% aqueous solution.

Next, 18.5 parts (0.2 mol) of epichlorohydrin was charged and the mixture was incubated at 65°C for 2 hours. Then, 8.1 parts (0.1 mol) of 37% formalin was added and the pH was adjusted to 5 with 70% sulfuric acid. , and reacted at 65°C for 4 hours.

After that, it was cooled to 25°C, and the pH was adjusted to 7 with a 28% caustic soda aqueous solution, and the concentration was 50% and the viscosity was 48cp (at 25°C).
) was obtained. This is called resin liquid.

Reference example-5 Ethylene glycol 12.4 in the same container as reference example-1
(0.2 mol) and 60.0 parts (0.2 mol) of tetrahydrophthalic anhydride.
Pour 8 parts (0.4 mol) and heat at 140°C for 2 hours.
A reaction product with free carboxyl groups was obtained. Add 12.0 parts (0.2 mol) of urine S to this and add 110~
Triethylenetetramine 58. with stirring at 120°C.
5 parts (0.4 mol) were added.

This was subjected to deammonia reaction and dehydration amidation reaction at 150° C. for 5 hours. This was cooled to 130°C and further deep 12. Add O part (0.2 mol), temperature 120-130
Ammonia removal reaction was carried out at ℃ for 2 hours. Thereafter, it was cooled to 100°C and water was added to make a 50% aqueous solution. Next, 77 parts (0.5 mol) of diethyl sulfuric acid was added, and the mixture was heated at 60°C.
Allowed time to react. After that, it was cooled to 25°C, the pH was adjusted to 7 with 20% sulfuric acid, and water was added to give a concentration of 50% and a viscosity of 4.
A resin liquid of 3 cp (25° C.) was obtained. This is called resin liquid E.

Reference Example-6 In Reference Example-4, instead of 8.1 parts of 37% formalin, 14.5 parts of 40% glyoxal (0°1 mol)
The procedure was repeated in the same manner as in Reference Example 4, except that the pH was adjusted to 6 with 70% sulfuric acid and the reaction was carried out at 55°C for 4 hours. A resin liquid was obtained. This is called resin liquid F.

Comparative Reference Example-1 According to Reference Example-1, 29°6 parts of phthalic anhydride (0,2
Everything was synthesized using the same raw materials and under the same conditions, except that mol) was used, and the final product was 8 degrees 50%, viscosity 49 cp (25
) was obtained. This is called resin liquid G.

Comparative Reference Example-2 According to Reference Example-1, all materials were the same, except that 29.2 parts (0.2 mol) of adipic acid was used instead of hexahydrophthalic anhydride in Reference Example-1. The final concentration was 50% and the viscosity was 58cp (25°C).
A resin liquid was obtained. This is called resin liquid H.

Comparative Reference Example-3 According to Reference Example-5, 58.5 parts of adipic acid (0.4 parts
mol) and 12.4 parts (0.2 mol) of ethylene glycol
The mixture was then heated at 160 to 180° C. for 3 hours to undergo dehydration and esterification, thereby obtaining a polyester having carboxyl groups at the terminals. Further, 12.0 parts (0.2 mol) of urea was added thereto, and 58.5 parts (0.4 mol) of triethylenetetramine was added while stirring at 110 to 120°C. This at 150℃
Deammonification and dehydration amidation reactions were carried out for 5 hours. This was cooled to 130°C, 12.0 parts (0.2 mol) of urea was added, and ammonia removal reaction was carried out at a temperature of 120 to 130°C for 2 hours. The drained water was added to make a 50% aqueous solution. Next, 77 parts (0.5 mol) of diethyl sulfuric acid was added,
The reaction was carried out at 60°C for 4 hours.

After that, it was cooled to 25℃, the pH was adjusted to 7 with 20% sulfuric acid, and water was added to give a concentration of 50% and a viscosity of 57cp (25℃).
A resin liquid was obtained. This is called resin liquid I.

Examples 1 to 6 Using the resins obtained in Reference Examples 1 to 6 (resin liquids A-F),
A paper coating composition having the formulation shown in Table 1 was prepared.

Table - Notes: ■Ultra White 90 (clay manufactured by Engel Hard Minerals, USA) ■Carbicle 90 (calcium carbonate manufactured by Fuji Kaolin A↑) ■Sumiraizu Resin DS-10 (polyacrylic manufactured by Sumiya Kagaku Kogyo ■) Acid-based pigment dispersant) ■Styrene-butadiene latex manufactured by 5N-307 (Resident Naugatuck 0$)) ■To Tamago Ace (Tamago National Starch a oxidized starch manufactured by Kosha) ■The heavy base portion represents the solid content weight .

The prepared paper coating composition had a total solids content of 60%, p)I
After adjusting each with water and a 10% caustic soda aqueous solution so that the ratio is approximately 8.5,
0 g/m' high-quality paper with a coating weight of 14 g/m'
It was coated on one side so that Immediately after application, dry blast with hot air at 120°C for 30 seconds, then condition the humidity at 20°C and 65% RH for 16 hours, then apply at a temperature of 60°C and a linear pressure of 60 kg/c.
A coated paper was obtained by supercalendering twice under the conditions of m. The coated paper thus obtained was subjected to tests for water resistance, ink receptivity, and formaldehyde quantification. The test results are shown in Table 2 as Examples 1 to 6.

The test method is as follows.

Water Resistance (a) Wet Rub Method: 12 drops of approximately 0.1 m of ion-exchanged water were placed on the coated surface, rubbed 7 times with fingertips, the eluted portion was transferred to black paper, and the eluted base was determined visually.

The evaluation criteria were as follows.

Water resistance (poor) 1 to 5 (excellent) (b) Using a wet pick method RI tester, moisten the coated surface with a water supply roll, print, and visually observe the peeling condition to determine water resistance (poor). )
A rating of 1 to 5 (excellent) was made.

Ink receptivity (a) Method A Using a R1 tester (Mei Seisakusho), the coated surface was moistened with a water supply roll and then printed, and the ink receptivity was observed.

Ink receptivity (poor): 1 to 5 (excellent).

(b) Using a B method RI tester, printing was carried out while kneading water into the ink, and the ink receptivity was observed.

Ink receptivity (poor): 1 to 5 (excellent).

○ Quantification of formaldehyde 2.5 g of coated paper sample was taken and quantified according to JIS-L1041-1976 liquid phase extraction method (2) acetylacetone method (method A).

Comparative Examples 1 to 4 Resin liquid G-I obtained in Comparative Reference Examples 1 to 3 and violet resin 613 (water-soluble melamine manufactured by Susumu Kagaku Kogyo Co., Ltd.)
Formaldehyde resin) was used as the resin in the same paper coating composition as in Examples 1 to 6, and coated paper was prepared according to the same example, and the results of the tests were the same (shown in Table 2).

Claims (1)

[Scope of Claims] (I) pigment, (II) aqueous binder, and (III) (a) polyalkylene polyamine (b) alicyclic dibasic carboxylic acid and/or alicyclic dibasic carboxylic acid and glycol (c) a urea, (d) an alkylating agent and, if desired, (e) a resin reacted with formaldehyde and/or glyoxal. Coating composition for paper.