JPH064956B2 - Coating composition for paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a paper coating composition which provides a coated paper having excellent printability and printing effect.

<Prior Art> A coated paper obtained by applying a coating composition for paper mainly composed of a pigment and an aqueous binder to a paper and performing necessary steps such as drying and calendering has excellent printing effect. It is widely used for commercial prints, magazines, books, etc. due to its features, but efforts are being made to improve the quality of coated paper as demand for quality becomes higher and printing speed increases. Especially in offset printing, which occupies most of printing, ink acceptability under the influence of squeezing water, water resistance of wet topics and wet rubs, improvement of blister resistance in rotary printing,
Improvement is an important issue for the industry.

Conventionally, melamine-formaldehyde resin, urea-formaldehyde resin or polyamide polyurea-formaldehyde resin such as Japanese Patent Publication No.
There is known a method in which a water-proofing agent and the like shown in 4-1-1667 and JP-B-59-32597 are added to try to solve the problem.

<Problems to be Solved by the Invention> However, all of the conventionally used waterproofing agents and the like have effective properties, but on the other hand, they have serious drawbacks and are not satisfactory in practice.

For example, aminoplast resins such as melamine-formaldehyde resin and urea-formaldehyde resin not only generate a large amount of formaldehyde at the time of work and coated paper, but also hardly obtain the effect of improving ink acceptability and blister resistance. Also, the water resistance effect becomes extremely difficult to obtain as the pH of the coating composition increases. Furthermore, the polyamide polyurea-formaldehyde resin is effective in improving not only water resistance but also ink acceptability and blister resistance, but the degree of improvement is still unsatisfactory with the recent demand for higher quality coated paper. It is sufficient and there is a demand for higher performance. The object of the present invention is to meet such requirements, by using a coating composition for paper containing a specific resin, imparts to the coated paper a high degree of water resistance, ink acceptability and the like, which cannot be obtained by conventional techniques. Especially.

<Means for Solving the Problem> The present inventors have earnestly studied to obtain a paper coating composition that imparts high water resistance to coated paper, ink acceptability, etc.,
(I) pigment, (II) aqueous binder, and (III) (a) polyalkylene polyamine (b) alicyclic dibasic carboxylic acid and / or reaction of alicyclic dibasic carboxylic acid with glycols The resulting reaction product having a free carboxyl group (c) ureas (d) polyvalent aldehyde and if desired (e) a paper coating composition containing a thermosetting resin reacted with a monovalent aldehyde, The present invention has been completed by finding that it is extremely effective in improving the intended performance of coated paper. The present invention is characterized by using the above-mentioned thermosetting resin (III), and further, alicyclic dibasic carboxylic acid and / or reaction component (b) forming the (III) The use of a reaction product having a free carboxyl group obtained by the reaction of an alicyclic dibasic carboxylic acid and a glycol is characterized.

The contents of the present invention will be described in more detail.

The (a) polyalkylene polyamine used in the production of the thermosetting resin (III) used in the present invention is a compound having two primary amino groups and at least one secondary amino group in the molecule, Specifically, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine, 3-azahexane-1,6-diamine, 4,7-diazadecane-
1,10 diamine etc. are mentioned. These polyalkylene polyamines can be used not only as one kind but also as a mixture of two or more kinds. Further, it does not hinder the combined use of the aliphatic diamine such as ethylenediamine and propylenediamine with the above-mentioned polyalkylenepolyamine within a range not impairing the object of the present invention.

Next, (b) an alicyclic dibasic carboxylic acid is a generic term that includes compounds having two carboxyl groups in the molecule, their esters, and their acid anhydrides. Representative examples of such alicyclic dibasic carboxylic acid are as follows.

Carboxylic acids such as tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexane-1,4-dicarboxylic acid, 4-methyltetrahydrophthalic acid and their esters, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4- Acid anhydrides such as methyl tetrahydro phthalic anhydride, 4-methyl heisahydro phthalic anhydride, Δ ⁴ -tetrahydro phthalic anhydride, and 4-methyl-Δ ⁴ -tetrahydro phthalic anhydride.

These may be only one kind or a combination of two or more kinds,
Further, together with 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, to the extent that the effects of the present invention are not impaired. An acid may be used in combination.

Examples of glycols include alkylene glycols such as ethylene glycol, propylene glycol and butanediol, cycloalkylene glycols such as cyclopentanediol and cyclohexanediol, alkenylene glycols such as butenediol and octenediol, diethylene glycol and dipropylene glycol. ,
Polyalkylene glycols such as triethylene glycol, polyethylene glycol, polytetramethylene glycol, ethylene oxide adduct of bisphenol A,
Examples thereof include ethylene oxide adducts of hydrogenated bisphenol A.

Furthermore, as the reaction product having a free carboxyl group obtained by the reaction of an alicyclic dibasic carboxylic acid and glycols, the alicyclic dibasic carboxylic acid and the glycols can be used as a carboxylic acid excess mole. It is a polyester having a carboxyl group at the molecular end obtained by reacting in a ratio. The reaction between the alicyclic dibasic carboxylic acid and glycols is usually carried out at 80 to 200 in the presence or absence of a catalyst.
It is carried out by heating at 30 ° C. for 30 minutes to 2 hours.

Further, (c) urea includes urea, thiourea, guanylurea,
Urea is preferable from an industrial viewpoint, such as methylurea and dimethylurea.

Next, as the (d) polyvalent aldehyde, glyoxal,
Examples thereof include glutaraldehyde.

Further, as (e) monovalent aldehyde, formaldehyde,
Acetaldehyde, propionaldehyde, acrolein, glyoxylic acid, glycolaldehyde and the like can be mentioned, but formaldehyde is preferable from the industrial viewpoint.

Next, the reaction method of each component (a), (b), (c) (d) and (e) will be described. The resin of the present invention has, for example, components (a), (b) and (c)
It can be produced by reacting the reaction product of (d) with (e) if desired. This component (a), (b) and
The reactions of (c) can be carried out in any order.

First of all, the components (a) and (b) can be reacted and then the component (c) can be reacted. The reaction between the components (a) and (b) is carried out at a temperature of 120 to 250 ° C., preferably 130 to 200 ° C., for 2 to 12 hours while removing generated water out of the system. The carboxy group in the component (b) is reacted at a ratio of 0.4 to 4 equivalents, preferably 0.8 to 3 equivalents, relative to 1 mol of the polyalkylene polyamine of the component (a). The reaction between the dehydration condensation reaction product thus obtained and the urea of the component (c) is performed at a temperature of 100 to 180 ° C., preferably 110 to 180 ° C.
It is carried out at 160 ° C. for 1 to 6 hours while removing generated ammonia out of the system. The amount of the component (c) used is based on 1 equivalent of the amino group in the component (a), that is, the primary and secondary amino groups.
It is 1 equivalent or less, preferably 0.1 to 0.8 equivalent.

Alternatively, the components (a) and (c) can be reacted first, then the component (b), and then the component (c). The component (c) is used in an amount of 0.2 to 1 mol, preferably 0.3 to 0.8 mol, per 1 mol of the component (a), and the temperature is 100.
The deammonification reaction is performed at ˜180 ° C., preferably 110 to 160 ° C. for 1 to 6 hours.

The reaction of the reaction product thus obtained with the component (b) is carried out at a temperature of 120 to 250 ° C., preferably 130 to 200 ° C.
It is carried out at 2 ° C for 2 to 12 hours while removing generated water out of the system at ℃. Component (b) contains 0.2 to 1 mol of component (a).
2 equivalents are preferably used in the range of 0.3 to 1.8 equivalents. The step of reacting the reaction products of the components (a), (b) and (c) thus obtained with the component (c) again is carried out at a temperature of 100 to 180 ° C., preferably 110 to 160 ° C. 1
~ 6 hours. The amount of the component (c) used is not more than 2 equivalents, preferably not more than 0.1 equivalent to 1 equivalent of the secondary amino group in the component (a).
It is in the range of 1 to 1.5 equivalents.

As still another method, the components (a), (b) and (c) may be simultaneously reacted, and the resulting reaction product may be further reacted with the component (c). The reaction of the first components (a), (b) and (c) is carried out at a temperature of 100 to 200 ° C., preferably 110 to 180.
It is performed at 2 ° C. for 2 to 12 hours while removing generated ammonia and water out of the system. In this step, the proportion of each component used is 0.2 to 2 equivalents, preferably 0.3 to 1.8 equivalents of the carboxyl group of component (b), relative to 1 mol of component (a).
(c) 0.2 to 1 mol, preferably 0.3 to 0.8 mol is suitable. The step of further reacting the component (c) with the reaction product thus obtained is carried out at a temperature of 100 to 180 ° C.
It is preferably carried out at 110 to 160 ° C. for 1 to 6 hours. The amount of the component (c) used is appropriately 2 equivalents or less, preferably 0.1 to 1.5 equivalents, relative to 1 equivalent of the secondary amino group of the component (a).

Components obtained by various methods as described above (a), (b) and
All the reaction products of (c) are dissolved in water and then reacted with a polyvalent aldehyde and, if desired, a monovalent aldehyde. This reaction is carried out at a concentration of 20 to 70% by weight, preferably 3
In an aqueous solution of 0 to 60% by weight at a temperature of 40 to 80 ° C.
It will be held for 10 hours. The amount of polyhydric aldehyde at this time is 0.05 to 1.0 mol, preferably 0.1 to 0.8 mol, per 1 mol of component (c). The amount of monovalent aldehyde is 0.1 to 1 mol of the component (c).
1.0 mol, preferably 0.2 to 0.7 mol is suitable. After completion of the reaction, if necessary, the pH is adjusted to 4 to 7 by adding an alkali such as caustic soda or potassium hydroxide, or an acid such as hydrochloric acid or sulfuric acid.

The resin thus obtained is obtained in the form of an aqueous solution, and the viscosity of an aqueous solution having a resin solid content of 50% by weight is usually 5 to 1000 centipoise (hereinafter cp).
Abbreviated), the one having an extremely low viscosity tends to have a low effect of adding a resin as a paper coating composition, and the one having a high viscosity is a prepared paper coating composition. Since the viscosity becomes high and it may be accompanied by an unfavorable disadvantage in general, a resin having a viscosity range of 10 to 500 cp, particularly preferably 20 to 200 cp is preferably used practically.

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

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

The composition ratio of the paper coating composition of the present invention is (I) Pigment 10
1 to 50 parts by weight, preferably 6 to 40 parts by weight, (III) thermosetting resin 0.05 to 10 parts by weight, preferably 0.1 to 3 parts by weight, relative to 0 parts by weight. Is. The solid content concentration of the coating composition is 20 to 75% by weight.

Generally, the thermosetting resin (III) used in the present invention is added and mixed with the pigment and the aqueous binder during the preparation of the coating composition for paper. The effect of the invention can be obtained.

The paper coating composition of the present invention requires a dispersant, a viscosity / fluidity modifier, an antifoaming agent, a preservative, a lubricant, a water retention agent, a dye, a colorant such as a colored pigment, and the like as other components. Can be blended accordingly.

Further, in the process of preparing the coating composition of the present invention, the mixing order of each component is not particularly limited, but dispersion stability as a composition decreases due to different ionicity and the like. Therefore, it is desirable to select the compounding order, the solid content concentration of each component at the time of compounding, the pH of the coating composition, etc., and to carry out the process.

The paper coating composition of the present invention is a conventionally known method, that is, a blade coater, an air knife coater, a roll coater, a size press coater, a gate roll coater, a cast coater, etc. Coated paper can be produced by applying, performing necessary drying by a usual method, and further performing super calendering treatment if necessary.

<Effects of the Invention> The coated paper thus obtained using the coating composition for paper of the present invention is excellent in ink acceptability, water resistance, improved glossiness, improved opacity, blister resistance, etc. It has various excellent and effective characteristics such as no generation of odor.

The "paper" of the paper coating composition in the present invention has a broad meaning and includes a narrow meaning of paper and paperboard.

<Example> Hereinafter, the present invention will be described in more detail with reference to Examples and Examples. All% and parts in the text represent% by weight and parts by weight.

Reference Example-1 (Synthesis of Thermosetting Resin (III)) Triethylenetetramine 58.5 parts (0.4 mol) in a four-necked flask equipped with a thermometer, a reflux condenser and a stirring bar.
And 12.0 parts (0.2 mol) of urea were charged and the internal temperature was 120-
The mixture was heated at 140 ° C. for 3 hours to carry out a deammonification reaction.
Then, 34.4 parts (0.2 mol) of hexahydrophthalic acid was charged and a dehydration amidation reaction was performed at an internal temperature of 150 to 160 ° C. for 5 hours. Then, the internal temperature was cooled to 130 ° C., and 48.0 parts (0.8 mol) of urea was charged and the temperature was adjusted to 120.
Ammonia reaction was carried out at 2 ° C to 130 ° C for 2 hours. Then, it cooled to 100 degreeC, and water was added, and it was set as a 50% aqueous solution.
Then, 58 parts (0.4 mol) of 40% glyoxal was added, the pH was adjusted to 6 with 35% hydrochloric acid, and then the mixture was mixed at 50 ° C. for 3 hours.
Reacted for hours. After the reaction, cool down to 25 ° C and adjust the concentration to 47.
%, A resin liquid having a viscosity of 46 cp (25 ° C.) was obtained. This is referred to as resin liquid A.

Reference Example-2 Triethylenetetramine 5 was placed in the same container as Reference Example-1.
8.5 parts (0.4 mol) and 12.0 parts (0.2 mol) of urea were charged and heated at an internal temperature of 120 to 140 ° C. for 3 hours,
A deammonification reaction was performed. After that, NH-2200 (manufactured by Hitachi Chemical Co., Ltd., alicyclic acid anhydride, below formula) Charge 33.2 parts (0.2 mol) and the internal temperature is 150-160.
A dehydration amidation reaction was performed at 5 ° C. for 5 hours. Thereafter, the internal temperature was cooled to 130 ° C., 12.0 parts (0.2 mol) of urea was charged, and a deammonification reaction was performed at a temperature of 120 to 130 ° C. for 2 hours. Then cool to 100 ° C and add water to add 5
It was a 0% aqueous solution.

Next, 29 parts (0.2 mol) of 40% glyoxal was charged, the pH was adjusted to 6.5 with 70% sulfuric acid, the temperature was raised to 60 ° C., and the reaction was carried out at 60 ° C. for 4 hours. Then 2
Cooled to 5 ° C, concentration 48.5%, viscosity 47 cp (25
To obtain a resin liquid (° C.). This is referred to as resin liquid B.

Reference Example-3 Triethylenetetramine 5 was placed in the same container as Reference Example-1.
8.5 parts (0.4 mol) and tetrahydrophthalic anhydride 30.4 parts (0.2 mol) and further 12 parts urea (0.2 mol)
Mol) was simultaneously charged and the temperature was raised to perform dehydration amidation and deammonification reaction at 150 to 155 ° C. for 5 hours at the same time. Then cool to 130 ° C. and further 12 parts of urea (0.2 mol)
Was charged, and a deammonification reaction was performed at 125 to 130 ° C. for 2 hours. Water was added to this and diluted to obtain an aqueous solution having a concentration of 50%.

Next, 80 parts of 25% glutaraldehyde aqueous solution (0.2
Mol) was added, the pH was adjusted to 6.5 with 70% sulfuric acid, and then the mixture was reacted at 55 ° C. for 7 hours. Then, it was cooled to 25 ° C. to obtain a resin liquid having a concentration of 45% and a viscosity of 42 cp (25 ° C.). This is referred to as a resin liquid C.

Reference Example-4 Triethylenetetramine 2 was placed in the same container as Reference Example-1.
9.2 parts (0.2 mol) was charged, 30.8 parts (0.2 mol) of hexahydrophthalic anhydride was added thereto, the temperature was raised, and dehydration amidation was performed at 150 to 155 ° C. Then, the mixture was cooled to 130 ° C., 12 parts (0.2 mol) of urea was charged, and a deammonification reaction was performed at 125 to 130 ° C. for 2 hours. Next, this was cooled to 60 ° C., and water was added to dilute it to obtain a 50% aqueous solution. Next, 14.5 parts (0.1 mol) of 40% glyoxal was charged, the pH was adjusted to 6 with 35% hydrochloric acid, and the mixture was reacted at 65 ° C. for 2 hours. After that, it was cooled to 25 ° C and the concentration was 48.5% and the viscosity was 58 cp.
A resin liquid of (25 ° C.) was obtained. This is referred to as resin liquid D.

Reference Example-5 Ethylene glycol 12.4 in the same container as Reference Example-1.
Parts (0.2 mol) and tetrahydrophthalic anhydride 60.
8 (0.4 mol) was charged and heated at 140 ° C. for 2 hours to obtain a reaction product having a free carboxyl group. To this, 12.0 parts (0.2 mol) of urea was further charged and 110 to 120
58.5 parts (0.4 mol) of triethylenetetramine was added with stirring under ° C.

This was subjected to deammonification reaction and dehydration amidation reaction at 150 ° C. for 5 hours. This is cooled to 130 ° C., 12.0 parts (0.2 mol) of urea is further added, and the temperature is 120 to 130.
Deammonification reaction was carried out at ℃ for 2 hours. Then, it cooled to 100 degreeC, and water was added, and it was set as a 50% aqueous solution. Then 40
% Glyoxal 14.5 parts (0.1 mol) was charged,
After adjusting the pH to 7 with 70% sulfuric acid, the mixture was reacted at 60 ° C. for 3 hours. Then, it was cooled to 25 ° C. to obtain a resin liquid having a concentration of 49% and a viscosity of 49 cp (25 ° C.). This is resin liquid E
Called.

Reference Example-6 Triethylenetetramine 5 was placed in the same container as Reference Example-1.
8.5 parts (0.4 mol) and urea 12.0 (0.2 mol)
Was charged and heated at an internal temperature of 120 to 140 ° C. for 3 hours to carry out a deammonification reaction. Thereafter, 30.4 parts (0.2 mol) of tetrahydrophthalic anhydride was charged, and the internal temperature was 150-
A dehydration amidation reaction was performed at 160 ° C. for 5 hours. Then, the internal temperature was cooled to 130 ° C., 48 parts (0.8 mol) of urea was charged, and a deammonification reaction was performed at a temperature of 120 to 130 ° C. for 2 hours. Then, it cooled to 100 degreeC, and water was added, and it was set as a 50% aqueous solution. Then 40% glyoxal 29
Part (0.2 mol) was added, the pH was adjusted to 6 with 70% sulfuric acid, and then the mixture was reacted at 60 ° C. for 3 hours. Then 37%
Formalin 16.2 (0.2 mol) was charged, the pH was adjusted to 5 with 70% sulfuric acid, and the reaction was carried out again at 60 ° C. for 3 hours. After completion of the reaction, the mixture was cooled to 25 ° C., the pH was adjusted to 6 with 28% caustic soda, the concentration was 48%, the viscosity was 56 cp (25
To obtain a resin liquid (° C.). This is referred to as a resin liquid F.

Reference Example-7 Triethylenetetramine 5 was placed in the same container as Reference Example-1.
8.5 parts (0.4 mol) and 12 parts (0.2 mol) of urea were charged, and a deammonification reaction was carried out at 145 to 150 ° C. for 4 hours. In another container, tetrahydrophthalic anhydride 6
0.8 parts (0.4 mol) and propylene glycol 15.
2 parts (0.2 mol) were mixed and heated at 140 to 150 ° C. for 2 hours to obtain polyester. The entire amount of this polyester was charged into a container that had completed the above-mentioned deammonification reaction, and the internal temperature was heated at 150 to 155 ° C. for 4 hours to perform dehydration and deammonification reaction. Then cool to 130 ° C. and urea 12
Part (0.2 mol) was added, and a deammonification reaction was performed at 125 to 130 ° C. for 2 hours. Thereafter, water was added to form a 50% aqueous solution, and 40 parts (0.1 mol) of a 25% glutaraldehyde aqueous solution and 4 parts (0.05 mol) of a 37% formalin were charged therein, and then the pH was adjusted to 70% with sulfuric acid to a pH of 5. Adjusted to 5. This was heated to 70 ° C., reacted at 70 ° C. for 4 hours, cooled to 25 ° C., and adjusted to pH 6.5 with 28% caustic soda. Concentration 47.5%, viscosity 46c
A resin liquid of p (25 ° C.) was obtained. This is referred to as a resin liquid G.

Comparative Reference Example-1 According to Reference Example-1, the same raw materials and the same conditions were used except that 29.6 parts (0.2 mol) of phthalic anhydride was used instead of hexahydrophthalic acid of Reference Example-1. Finally, a resin liquid having a concentration of 47% and a viscosity of 44 cp (25 ° C.) was obtained. This is called a resin liquid H.

Comparative Reference Example-2 According to Reference Example-1, 29.2 parts (0.2 mol) of adipic acid was used in place of the hexahydrophthalic acid of Reference Example-1.
Except for being used, all were synthesized under the same raw material and under the same conditions, and finally a resin liquid having a concentration of 47% and a viscosity of 51 cp (25 ° C.) was obtained.

This is referred to as resin liquid I.

Comparative Reference Example-3 According to Reference Example-1, first, 58.5 parts of adipic acid (0.
4 mol) and 12.4 parts (0.2 mol) of ethylene glycol were heated at 160 to 180 ° C. for 3 hours to be dehydrated and esterified to obtain a polyester having a carboxy group at a terminal. Add 12.0 parts (0.2 mol) of urea to this and add 1
Triethylenetetramine 5 while stirring at 10 to 120 ° C
8.5 parts (0.4 mol) were added. 5 at 150 ℃
Time deammonification and dehydration amidation reaction were performed. This was cooled to 130 ° C., 12.0 parts (0.2 mol) of urea was added, and a deammonification reaction was performed at a temperature of 120 to 130 ° C. for 2 hours. Then, water was added to make a 50% aqueous solution. Next, 14.5 parts (0.1 mol) of 40% glyoxal was charged, the pH was adjusted to 7 with 70% sulfuric acid, and then the mixture was reacted at 60 ° C. for 3 hours. Then cool to 25 ° C and
%, A resin liquid having a viscosity of 46 cp (25 ° C.) was obtained. This is referred to as a resin liquid J.

Examples 1 to 7 The thermosetting resins (resin liquids A to G) obtained in Reference Examples 1 to 7 were used to prepare paper coating compositions having the formulations shown in Table 1.

The prepared paper coating composition was prepared with water and a 10% caustic soda aqueous solution so that the total solid content was 60% and the pH was about 8.5, and the wire basis was used to weigh 80 g of rice.
It was coated on one surface of high-quality paper / m ^{2 so} as to have a coating amount of 14 g / m ² . Immediately after coating, air-heat-dry at 120 ° C for 30 seconds, and then humidity control at 20 ° C and 65% RH for 16 hours, and then super calender treatment is performed twice at a temperature of 60 ° C and a linear pressure of 60 kg / cm. I got coated paper. The coated paper thus obtained was tested for water resistance, ink acceptability, and formaldehyde determination. The test results are shown in Table 2 as Examples 1 to 7.

The test method is as follows.

○ Water resistance (a) Wet rub method About 0.1 ml of ion-exchanged water was dropped on the coated surface and rubbed with a fingertip 7 times, and the eluted amount was transferred to black paper to visually judge the eluted amount.

The criteria for judgment were as follows.

Water resistance (poor) 1 to 5 (excellent) (b) Wettopic method Using a RI tester, wet the coated surface with a water supply roll, then print, and observe the peeled state with the naked eye to determine the water resistance (poor). )
The judgment of 1 to 5 (excellent) was performed.

○ Ink acceptability (b) Method A Using an RI tester (Ming Seisakusho), the coated surface was wetted with a water supply roll and then printed, and the acceptability of the ink was observed.

The ink acceptability (poor) is 1 to 5 (excellent).

(B) Method B Using an RI tester, ink was printed while kneading water, and the ink acceptability was observed.

The ink acceptability (poor) is 1 to 5 (excellent).

○ Quantification of formaldehyde JIS-L1041-1976 liquid phase extraction method (2) According to the acetylacetone method (method A), 2.5 g of a coated paper sample was sampled and quantified.

Comparative Examples 1 to 4 Resin liquids H to J obtained in Comparative Reference Examples 1 to 3 and Sumirez Resin 613 (water-soluble melamine-formaldehyde resin manufactured by Sumitomo Chemical Co., Ltd.) were used for the same papers as in Examples 1 to 7. The thermosetting resin used in the coating composition was used to prepare coated paper according to the same example, and the test results are also shown in Table 2.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiya Fukuyama 3-98 Kasugadenaka, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Chemical Co., Ltd. (56) Reference JP-A-59-137597 (JP, A) )

Claims (1)

[Claims] 1. An (I) pigment, (II) aqueous binder, (III) (a) polyalkylene polyamine, (b) alicyclic dibasic carboxylic acid and / or alicyclic dibasic carboxylic acid Contains a reaction product having a free carboxyl group obtained by reaction with glycols, (c) ureas, (d) polyvalent aldehyde, and (e) thermosetting resin reacted with monovalent aldehyde if desired A coating composition for paper characterized by being: