JPH07100918B2 - Coating composition for paper - Google Patents

Description

The present invention relates to a paper coating composition which provides a coated paper having excellent printability and printing effect.

More specifically, ink acceptability in a high pH coating composition,
The present invention relates to a paper coating composition which is excellent in water resistance and prister resistance and provides a coated paper that does not generate a formaldehyde odor.

A coated paper obtained by applying a coating composition for paper mainly composed of a pigment and an aqueous binder to paper and subjecting it to necessary steps such as drying and calendering is a commercial printed product because of its excellent printing effect. Although it is widely used in magazines, books, and so on, efforts have been made to improve the quality of coated paper as quality requirements become 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, for such purposes, various water-resistant products have been added to a paper coating composition mainly composed of a pigment and an aqueous binder to improve the quality of the coated paper. Although the agents and the like all have effective properties, they are not satisfactory in practice because of serious drawbacks.

For example, an aminoplast resin such as a melamine-formaldehyde resin or a urea-formaldehyde resin only produces a large amount of formaldehyde at the time of work or coated paper, and the effect of improving ink acceptability and prister resistance is hardly obtained. The water resistance effect becomes extremely difficult to obtain as the pH of the coating composition increases. Glyoxal and other dialdehydes cause the coated paper to be colored, and cannot improve the ink acceptability and prister resistance. Neither polyvalent metal salts such as zirconium can improve the ink acceptability and the prister resistance.

Under these circumstances, polyamide polyurea-as an effective agent for improving and improving ink acceptability, water resistance, and blister resistance
At present, formaldehyde resins are widely used. However, the polyamide polyurea-formaldehyde resin also remarkably deteriorates its efficacy, especially ink acceptability and water resistance, when the pH of the coating composition is high. Therefore, there has not been found a chemical agent that significantly improves or improves ink acceptability, water resistance, and prister resistance in a high pH coating composition.

As a result of intensive investigations by the present inventors in view of the present situation, a paper coating composition mainly composed of a pigment and an aqueous binder,
It has been found that the above object can be achieved by using a reaction product of a polyalkylene polyamine having a specific aqueous solution viscosity and a specific cation equivalent and an epihalodrin as an additive to complete the present invention.

That is, the present invention provides a reaction product of (a) a pigment, (b) an aqueous binder, and (c) a polyalkylene polyamine and epihalohydrin, and a 50 wt% aqueous solution of the reaction product has a viscosity of 10 to 500 at 25 ° C. Centipoise has a cation equivalent of more than 0.5 m-eq / g at pH 9 of 5 m
A coating composition for paper, which contains -eq / g or less and has a pH of 10 or more.

Examples of the polyalkylene polyamine in the present invention include diethylene triamine, triethylene tetramine,
Examples thereof include tetraethylenepentamine, pentaethylenehexamine, heptaethyleneoctamine, nonaneethylenedecamine, triethylenebis (trimethylene) hexamine, aminoethylpiperazine and iminobispropylamine. These polyalkylene polyamines may be used alone or in admixture of two or more. For the purpose of controlling or modifying the molecular weight, a monoamine such as diethylamine or dipropylamine or an alkylenediamine such as ethylenediamine, propylenediamine or hexamethylenediamine may be mixed with the polyalkylenepolyamine.

Examples of epihalohydrin include epichlorohydrin, epipromohydrin, and methylepichlorohydrin. The reaction product of polyalkylene polyamine and epihalohydrin is usually obtained as an aqueous solution having a solid content concentration of 20 to 80% by reacting polyalkylene polyamine and epihalohydrin at a temperature of 20 to 80 ° C. for about 30 minutes to 10 hours. To be

The reaction product of the polyalkylene polyamine and epihalohydrin of the present invention has a viscosity at 25 ° C. of not less than 10 centipoise and not more than 500 centipoise when the solid concentration of the aqueous solution is 50% by weight, and the cation equivalent at pH 9 is 0.5 m-eq /. It must be more than g and 5 m-eq / g or less. If the viscosity of the reaction product is less than 10 centipoise, the effect of the present invention is difficult to obtain, and if it exceeds 500 centipoise, the preparation of the coating composition becomes difficult. Further, the cation equivalent of the reaction product is
It is difficult to obtain the effect of the present invention at 0.5 m-eq / g or less,
If it exceeds eq / g, it becomes difficult to prepare a coating composition.

The paper coating composition of the present invention uses such a reaction product of a polyalkylene polyamine and epihalohydrin as a waterproofing agent and practically contains no other waterproofing agent. Further, the coating composition for paper needs to have a pH of 10 or more, and if the pH is less than 10, it becomes difficult to prepare the coating composition.

The pigment in the present invention includes white inorganic pigments such as kaolin, talc calcium carbonate, aluminum hydroxide, satin white and titanium oxide, and organic synthetic pigments such as polystyrene, melamine-formaldehyde resin and urea-formaldehyde resin, alone or in combination of two or more. It can be mixed and used.

The aqueous binder in the present invention is a water-soluble binder such as oxidized starch, phosphoric acid esterified starch, polyvinyl alcohol, casein, gelatin, carboxymethyl cellulose, styrene-butadiene resin, vinyl acetate resin, ethylene-vinyl acetate resin, methyl methacrylate. Water-emulsified binders such as resins may be used alone or in combination of two or more.

The paper coating composition of the present invention requires a dispersant, a viscosity, a fluidity adjusting agent, 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.

The coating composition for paper of the present invention is applied on a paper substrate by a conventionally known method, that is, a blade coater, an air knife coater, a roll coater, a size press coater, a cast coater, or the like, which is usually used. The coated paper can be produced by carrying out the required drying by the above method, and further subjecting it to a super calendering treatment if necessary.

In this way, the coated paper obtained using the coating composition for paper of the present invention has excellent ink acceptability, water resistance, and blister resistance,
It has various excellent and effective properties such as no generation of formaldehyde 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.

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

Example 1 1 mol of diethylenetriamine and 1 mol of epichlorohydrin
Moles were reacted in the presence of water at 60 ° C. for about 4 hours to obtain a diethylenetriamine-epichlorohydrin reaction product.
The viscosity of a 50% aqueous solution of the reaction product at 25 ° C. was 20 centipoise when measured with a B-type viscometer at 12 rpm. The cation equivalent of the reaction product at pH 9 was 3.1 m-eq / g as determined by colloid titration.

The diethylenetriamine-epichlorohydrin reaction product thus obtained was used to prepare a paper coating composition as follows.

First, 70 parts of Ultra White 90 (Clay made by Engelhard Minerals, Inc. in the United States), 15 parts of Shiratsuka PZ (light calcium carbonate made by Shiroishi Industry), 15 parts of Super 1500 (heavy calcium carbonate made by Maruo Calcium), Sumireze Resin DS −10
(Sumitomo Chemical's sodium polyacrylate dispersant) 0.3
Parts and 0.4 parts of caustic soda were dispersed in an appropriate amount of water to obtain a pigment slurry. Oji Ace A (oxidized starch manufactured by Oji National Co., Ltd.) pre-gelatinized to this pigment slurry
6 parts, SN-307 (Sumitomo Nogatak SB latex) 1
After adding 2 parts and stirring well, 0.5 part of the diethylenetriamine-epichlorohydrin reaction product was added and stirred, and the pH was adjusted to 11 with a caustic soda aqueous solution and water to a total solid content of 55%, and a coating composition for paper. I got a thing.

The coating composition using the experimental coating rod and coated to a coating weight 13 g / m ² on a high-quality paper of a basis weight amount 80 g / m ² for the paper immediately 120 ° C., subjected to oven drying for 30 seconds did. Next, this coated paper was conditioned at 20 ° C. and 65% RH for 16 hours, and then subjected to super calendering twice at a roll temperature of 60 ° C. and a roll linear pressure of 60 kg / cm to obtain a coated paper.

The coated paper was subjected to the following test after conditioning the humidity at 20 ° C. and 65% RH for 24 hours.

(1) Water resistance (a) Wet rub method About 0.1 ml of ion-exchanged water was dropped on the surface of coated paper and rubbed with a fingertip, and the elution state of the coating composition was observed and judged. The criteria for judgment are as follows.

Water resistance (excellent) 5 to 1 (poor) (b) Wettopic method Wet the coated surface with water using an RI tester (manufactured by Ming Seisakusho), then print to observe the picking occurrence state. It was judged. The criterion is the same as the wet lab method.

(2) Ink acceptability (b) Method A The ink acceptability of the ink was observed by making a print after moistening the coated surface with a RI tester and making a judgment. The criterion is the same as the wet lab method.

(B) Method B Using an RI tester, printing was performed while dripping water on the ink being kneaded, and the acceptability of the ink was observed and judged. The criterion is the same as the wet lab method.

(3) Blister resistance Double-sided printing was performed on double-sided coated paper using an RI tester, and after drying and humidity control, it was immersed in a silicone oil bath and the degree of blister generation was observed and judged. The criterion is the same as the wet lab method.

(4) Formaldehyde amount Quantified according to the liquid phase extraction method of JIS L-1041-1976 (2) Acetylacetone method (Method A).

The measurement test results are shown in Table 1.

Table 1 shows the pH of the coating composition at 25 ° C. and the viscosity of the B type viscometer at 25 rpm at 60 rpm.

Example 2 A tetraethylenepentamine-epichlorohydrin reaction product was obtained in the same manner as in Example 1 except that 1 mol of tetraethylenepentamine was reacted with 0.8 mol of epichlorohydrin. The viscosity of a 50% aqueous solution of the reaction product at 25 ° C was 33 centipoise, and the cation equivalent at pH 9 was 3.4 m-eq / g. Using the tetraethylenepentamine-epichlorohydrin reaction product thus obtained, a paper coating composition was obtained in the same manner as in Example 1, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 1.

Example 3 1 mol of triethylenetetramine and epichlorohydrin
A triethylenetetramine-epichlorohydrin reaction product was obtained in the same manner as in Example 1 except that 1.4 mol was reacted. The viscosity of a 50% aqueous solution of the reaction product at 25 ° C was 97 centipoise, and the cation equivalent at pH 9 was 2.5 m-eq / g. Using the triethylenetetramine-epichlorohydrin reaction product thus obtained, a paper coating composition was obtained in the same manner as in Example 1, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 1.

Example 4 A coating composition for paper was prepared as follows using the diethylenetriamine-epichlorohydrin reaction product obtained in Example 1.

First, 90,80 parts of Ultra White, 15 parts of White Gloss PZ, 5 parts of Satin White, 1.0 part of Sumireze Resin DS-10, and 0.6 parts of caustic soda were dispersed in an appropriate amount of water to obtain a pigment slurry. Solar eclipse MS pre-gelatinized to this pigment slurry
-4600 (Nippon Shokuhin Kako Co., Ltd. phosphate esterified starch)
After 6 parts and 12 parts of SN-307 were added and stirred well, the reaction product of diethylenetriamine-epichlorohydrin 0.3.
Parts and stir, adjust the pH to about caustic soda and water.
11.5, the total solid content was adjusted to 55% to obtain a coating composition for paper.

Using the coating composition for paper, a coated paper was obtained in the same manner as in Example 1. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 2.

Example 5 1 mol of tetraethylenepentamine to epichlorohydrin
1.2 mol was reacted in the presence of water at 60 ° C. for 4 hours to obtain a tetraethylenepentamine-epichlorohydrin reaction product. The viscosity of a 50% aqueous solution of the reaction product at 25 ° C is
It was 150 centimeters poise. The cation equivalent of the reaction product at pH 9 was 2.6 m-eq / g. Using the tetraethylenepentamine-epichlorohydrin reaction product thus obtained, a paper coating composition was obtained in the same manner as in Example 4, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 4. The measurement test results are shown in Table 2.

Comparative Example 1 1 mol of tetraethylenepentamine and epichlorohydrin
A diethylenetriamine-epichlorohydrin reaction product was obtained in the same manner as in Example 1 except that 1.6 mol was reacted. The viscosity of a 50% aqueous solution of the reaction product at 25 ° C was 540 centipoise, and the cation equivalent at pH 9 was 2.8 m-eq / g. Using the thus obtained tetraethylenepentamine-epichlorohydrin reaction product, an attempt was made to prepare a paper coating composition in the same manner as in Example 1, but a fluid paper coating composition could not be obtained. It was

Comparative Example 2 Using the diethylenetriamine-epichlorohydrin reaction product obtained in Example 1, an attempt was made to prepare a paper coating composition in the same manner as in Example 1 except that the pH of the paper coating composition was 9.5. However, a fluid paper coating composition could not be obtained.

Comparative Example 3 A paper coating composition was obtained in the same manner as in Example 1 except that the diethylenetriamine-epichlorohydrin reaction product was not used, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 1.

Comparative Example 4 A paper coating composition was obtained in the same manner as in Example 1 except that Sumirez Resin 613 (melamine-formaldehyde resin, manufactured by Sumitomo Chemical Co., Ltd.) was used instead of the diethylenetriamine-epichlorohydrin reaction product, and the coating composition was further applied. Got the paper. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 1.

Comparative Example 5 1 mol of tetraethylene pentamine to epichlorohydrin
0.5 mol was reacted in the same manner as in Example 1 to obtain a tetraethylenepentamine-epichlorohydrin reaction product.
The viscosity of a 50% aqueous solution of the reaction product at 25 ° C. was 40 centipoise. The cation equivalent at pH 9 is 5.2.
It was m-eq / g. Example 1 using the thus obtained tetraethylenepentamine-epichlorohydrin reaction product
An attempt was made to prepare a paper coating composition in the same manner as, but a fluid paper coating composition could not be obtained.

Comparative Example 6 A paper coating composition was obtained in the same manner as in Example 4 except that the diethylenetriamine-epichlorohydrin reaction product was not used, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 2.

Comparative Example 7 Ethylenediamine-1 mol was reacted with epichlorohydrin 0.8 mol under the same conditions as in Example 1 to obtain ethylenediamine-.
An epichlorohydrin reaction product was obtained. Of the reaction product
The viscosity of a 50% aqueous solution at 25 ° C was 6.5 centipoise, and the cation equivalent at pH 9 was 3.4 m-eq / g. Using the ethylenediamine-epichlorohydrin reaction product thus obtained, a paper coating composition was obtained in the same manner as in Example 4, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The test results are shown in Table 2.

Comparative Example 8 An ethylenediamine-epichlorohydrin reaction product was obtained in the same manner as in Example 1 except that 1 mol of ethylenediamine was reacted with 2.5 mol of epichlorohydrin. The viscosity of a 50% aqueous solution of the reaction product at 25 ° C. is 15
The cation equivalent at 0 centipoise or pH 9 is 0.4 m-
It was eq / g. Using the ethylenediamine-epichlorohydrin reaction product thus obtained, a paper coating composition was obtained in the same manner as in Example 4, and further a coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The measurement test results are shown in Table 2.

Comparative Example 9 A paper coating composition was obtained in the same manner as in Example 4 except that Sumirez Resin 633 (a polyamide-polyurea-formaldehyde resin manufactured by Sumitomo Chemical Co., Ltd.) was used in place of the diethylenetriamine-epichlorohydrin reaction product. Further, coated paper was obtained. The coated paper was subjected to the same measurement test as in Example 1. The test results are shown in Table 2.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigenao Kawakami 3-98 Kasugashin, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Yoshiya Fukuyama Kasuga, Osaka City, Osaka Prefecture Ichinaka 3-chome No. 98 Sumitomo Chemical Co., Ltd. (56) Reference JP-A-58-180695 (JP, A) JP-A-52-137015 (JP, A)

Claims (1)

[Claims] 1. A reaction product of (a) a pigment, (b) an aqueous binder, and (c) a polyalkylene polyamine and epihalohydrin, and 50% by weight of the reaction product.
The viscosity of the aqueous solution at 25 ° C is 10 to 500 centipoise, and the cation equivalent at pH 9 exceeds 0.5 m-eq / g and 5 m-e.
A coating composition for paper, which contains q / g or less (a), (b), and (c), but does not contain other waterproofing agent and has a pH of 10 or more.