JPH0115637B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of applying a surface size or clear coating to paper. Conventional paper surface sizing methods have been put into practical use, including oxidized starch alone, oxidized starch in combination with polyvinyl alcohol, raw starch alone, and raw starch in combination with polyvinyl alcohol. However, even if the above-mentioned surface size is applied to paper containing wood pulp made from southern hardwoods, coarse conduits scattered on or near the surface of the paper may be pulled out from the surface of the paper due to the tackiness of the printing ink during printing. Therefore, there is a problem that printing in that part becomes poor, and there is also a problem that the IGT pick strength is not necessarily sufficient. The phenomenon in which the conduit comes out of the paper surface during printing is called Bethel pick. The present invention solves the above problems, and consists of acid-modified polyvinyl alcohol (A) and modified starch (B) having a tertiary or quaternary amine in a ratio of 5% by weight.
It is characterized by treating paper with an aqueous solution containing the ratio of 95 to 70:30. By the method of the present invention, vessel picks can be effectively prevented even when paper has a large number of coarse conduits, and
IGT pick strength can also be maintained high, but this remarkable effect is due to acid-modified polyvinyl alcohol.
(A) and modified starch with tertiary or quaternary amine (B)
This effect can only be achieved by using a specific proportion of acid-modified polyvinyl alcohol (A) alone, or modified starch containing tertiary or quaternary amine (B) alone. Even if it is used in combination with acid-modified polyvinyl alcohol (A) and starch such as raw starch, oxidized starch, esterified starch, or etherified starch, it will not be possible to achieve the excellent effects as in the present invention. Acid-modified polyvinyl alcohol (A) in the present invention
Examples include unsaturated monocarboxylic acids or their salts such as acrylic acid and methacrylic acid, unsaturated dicarboxylic acids or their salts such as maleic acid, fumaric acid, itaconic acid, and anhydrides (these are collectively referred to as unsaturated carboxylic acids). ), unsaturated sulfonic acids such as ethylene sulfonic acid, allyl sulfonic acid, meta-allylsulfonic acid, N-sulfoalkyl acrylamide, and N-sulfoalkyl methacrylamide, or their salts (collectively referred to as unsaturated sulfonic acids). One example is one obtained by saponifying a copolymer of a component and vinyl acetate. The copolymerization ratio of the acid component is usually 0.1 to 10 mol%,
Preferably, it is selected from the range of 0.5 to 5 mol%; if the copolymerization ratio is too small, the anti-vessel pickling effect will be poor, while if it is too large, the viscosity of the blend will increase excessively, making surface sizing or coating processing difficult. I won't be able to do it. In addition, the degree of saponification of the vinyl acetate component is not particularly limited, but is 80 mol% or more,
In particular, it is preferably 85 mol% or more; if the degree of saponification is too low, problems such as blocking of the paper after coating will occur. Modified starch with tertiary or quaternary amines
(B) includes wheat starch, corn starch, tapioca starch, horse starch, rice starch, sweet starch,
Starch such as sago coconut starch, modified starch such as esterified starch, etherified starch, or starch derivatives are used as raw starches, and these raw starches are mixed with 2,3-epoxypropyltrimethylammonium chloride, 3-epoxypropyltrimethylammonium chloride, and 3-epoxypropyltrimethylammonium chloride in the presence of a strong alkali. Chloro-2-hydroxypropyltrimethylammonium chloride, 3-chloroethyltrimethylammonium chloride, 3-chloropropyltrimethylammonium chloride, 3-chloro-2-hydroxyethyltrimethylammonium chloride, 2-
Examples include those obtained by reacting with chloroethylene diamine, 3-chloro-2-hydroxydimethylamine, 2-diethylaminoethyl chloride, etc. The content of tertiary or quaternary amines in the modified starch thus obtained is 0.01 to 0.3, preferably 0.01 to 0.3 per glucose unit in the starch molecule.
It is necessary that 0.1 hydroxyl group is modified with a tertiary or quaternary amine; if the content is too low, it will lack the anti-vessel pickling effect, while if it is too high, it will increase the viscosity when mixed with (A). Sometimes. The modified starch (B) preferably has a low viscosity by modifying raw starch after processing with enzymes, acids, roasting, etc., or by performing these treatments after modification. . Commercial products of such modified starch (B) include Neotak #53 manufactured by Nihon Shokuhin Kako Co., Ltd., Neoposiparin manufactured by Matsutani Chemical Co., Ltd., Amylofax 00,
10, 15, Mermaid C manufactured by Shikishima Starch Co., Ltd.
-4, C-6, manufactured by Oji National Co., Ltd.
There are CATO series, etc. The ratio of the acid-modified polyvinyl alcohol (A) to the modified starch containing tertiary or quaternary amine (B) is 5:95 to 70:30 by weight, especially 10:90 to
It is selected from the range of 60:40, and if it deviates from this range, the anti-vessel pick-up effect will be insufficient, and (A)
If the ratio is too large, it will be disadvantageous in terms of coating workability and drying speed, and problems such as resin adhesion to the dryer will also occur. To treat paper, especially paper containing coarse conduits, dissolve (A) and (B) above in the prescribed proportions in water to reduce the solids content to approx.
Adjust to about 0.5 to 20% by weight, size press coat, calendar stack coat, roll coat,
A conventionally known surface sizing method or clear coating method is employed in which the coating is applied to the surface of paper by gate roll coating, bill blade coating, etc. and then dried. The sizing liquid or coating liquid may contain ingredients other than those listed above, such as polyvinyl alcohol, conventionally known surface paper strength enhancers such as oxidized starch, sizing agents such as rosin or petroleum-based sizing agents, antifoaming agents, release agents, and rust preventive agents. Agents and the like may be added as necessary. Paper treated according to the method of the present invention may be further subjected to pigment coating and other treatments. Next, the method of the present invention will be further explained with reference to Examples. In the following, "parts" and "%" are expressed on a weight basis unless otherwise specified. Example 1 A: Modified polyvinyl alcohol obtained by saponifying 99.2 mol% of the vinyl acetate component of a monomethyl maleate-vinyl acetate copolymer with a monomethyl maleate content of 2.2 mol% with caustic soda B: Nitrogen content 0.24%, 10% viscosity at 50℃
100 cps of quaternized cationized starch (Amylofax 10 manufactured by Matsutani Chemical Co., Ltd.) is made by reacting horse starch with 3-chloro-2-hydroxypropyltrimethylammonium chloride, and the degree of modification is 0.01 per glucose unit. The hydroxyl group is modified〉) The above A and B are 60/40, 50/50, 15/80 by weight.
An aqueous solution with a solid content concentration of 4 to 5% was prepared, and this aqueous solution was size-pressed onto general high-quality base paper with a basis weight of 65 g/m ² and a size degree of 2 seconds, which was made from pulp mixed with eucalyptus wood pulp. After that, it was dried in a cylindrical dryer at 120°C. 20 pieces of paper of this size
℃, 65% RH for 48 hours to adjust the humidity.
Physical properties were measured. The results are shown in Table 1. Control Examples 1 to 6 Paper surface sizes were carried out in the same manner as in Example 1, except that the following sizing liquids were used. Control example 1 Oxidized starch (MS- manufactured by Nihon Shokuhin Kako Co., Ltd.)
2. Control example of a 3% aqueous solution of polyvinyl alcohol with a degree of polymerization of 1700 and a degree of saponification of 99.0 mol%. 3. Control example of a 3% aqueous solution of A used in Example 1. 4. Control example of a 3% aqueous solution of A used in Example 1. 6% aqueous solution control example 5 A 4.5% solids concentration aqueous solution control example of a 1:1 mixture by weight of polyvinyl alcohol used in control example 2 and B used in example 1 6 A and A used in example 1 A 4.5% solids concentration aqueous solution of a 1:1 mixture with aminoethylated starch (by weight) The results of Control Examples 1 to 6 are shown in Table 1. In addition, in Control Examples 2 and 3, there was a large amount of resin adhering to the dryer.

[Table] (Note) Size degrees are Steckigt size degrees according to JIS-P-8122. Bethelpick uses an IGT printing suitability tester, ink TV10, B tension, printing pressure 50Kg/cm ²
After printing under these conditions, the number of Bethel picks was determined using a magnifying glass. IGT Pick uses the IGT printing suitability testing machine,
Measurement was carried out under the conditions of ink TV15, B tension, and printing pressure of 50 kg/cm ² . Examples 2 to 5 The surface size of paper was measured in the same manner as in Example 1 except that the following were used in place of A and B. Example 2 A: Modified polyvinyl alcohol obtained by alkali saponification of 92.1 mol% of the vinyl acetate component of a crotonic acid-vinyl acetate copolymer with a crotonic acid content of 3.2 mol% B: Modified starch Excell (manufactured by Nippon Deka Chemical Co., Ltd.) 6% viscosity 40cps at 30℃〈2,
Tertiary amine-modified starch is reacted with 3-epoxypropyldiethylamine, and the amount of modification is 0.02 hydroxyl groups per glucose unit. 〉) Example 3 A: Modified polyvinyl alcohol obtained by alkali saponification of 98.9 mol% of the vinyl acetate component of an itaconic acid-vinyl acetate copolymer with an itaconic acid content of 2.5 mol% B: B used in Example 1 Example 4 A: Modified polyvinyl alcohol obtained by alkaline saponification of 98.5 mol% of the vinyl acetate component of a N-sulfoisobutylene acrylamide sodium-vinyl acetate copolymer with a sodium N-sulfoisobutylene acrylamide content of 2.5 mol% B: Nitrogen content 0.21%, 6% viscosity at 30℃
6.4 cps quaternized cationized starch (Amylofax 15 manufactured by Matsutani Chemical Co., Ltd.) Example 5 A: Sodium allylsulfonate content 0.8 mol%
Modified polyvinyl alcohol obtained by alkali saponification of 98.5 mol% of the vinyl acetate component of the sodium allylsulfonate-vinyl acetate copolymer B: B used in Example 1 Example 6 A: Acrylic acid content 4.0 mol% Modified polyvinyl alcohol B obtained by alkali saponification of 99.0 mol% of the vinyl acetate component of the acrylic acid-vinyl acetate copolymer: B used in Example 1 The results of Examples 2 to 6 are shown in Table 2. .

【table】

Claims (1)

[Claims] 1 Acid-modified polyvinyl alcohol (A) obtained by saponifying a copolymer of unsaturated carboxylic acid or unsaturated sulfonic acid and vinyl acetate, and in which the degree of saponification of the vinyl acetate component is 80 mol% or more and starch molecules 0.01 to 0.3 hydroxyl groups per glucose unit of
tertiary or quaternary modified with a quaternary or quaternary amine
Modified starch (B) with grade amine and 5:95 to 95 by weight
A paper processing method characterized by processing paper using an aqueous solution containing a ratio of 70:30.