JP3244140B2 - Surface treatment method for paperboard - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating the surface of paperboard produced from pulp raw materials including waste paper,
More specifically, the present invention relates to a method for treating the surface of paperboard, which prevents the paperboard from adhering to each other when the paperboard is wound or stacked.

[0002]

2. Description of the Related Art In recent years, the recycling of waste paper has been increasing in the papermaking industry as a part of resource saving. Is being used. However, corrugated balls, magazines, and the like use a hot melt adhesive, a natural rubber adhesive, or a synthetic rubber adhesive for packaging, box making, and bookbinding. Therefore, in the case where corrugated balls, magazines and the like are reused as waste paper, maximum efforts are made to prevent the above-mentioned adhesive from being mixed into the recycled pulp. However, this cannot be completely prevented. Similarly, in the case of newspaper waste paper, the recycled pulp is generally contaminated with an ink binder.

[0003] Under such circumstances, pulp raw materials including recycled pulp derived from waste paper such as corrugated balls, newspapers, magazines, etc.
When paperboard is made, an adhesive substance (pitch) such as an adhesive or a binder is necessarily mixed in the paperboard. This adhesive substance is melted and exudes to the surface of the paper in the process of heating and drying the wet paperboard, thereby deteriorating the quality of the paperboard. Not only that, when storing paperboard, dirt is likely to adhere to the paperboard due to adhesive substances that have leached out of the surface.In addition, when paperboard is wound up or stacked, there is the disadvantage that paperboards will adhere to each other. there were.

As means for solving the above-mentioned problems of paperboard prepared by recycling waste paper, Japanese Patent Application Laid-Open No. 58-115 discloses a method.
197 proposes to apply or impregnate a paperboard with an aqueous solution containing a fluorine compound,
U.S. Pat. No. 4,923,566 proposes to apply an aqueous solution of urea to paperboard.

[0005]

Problems to be Solved by the Invention
The conventional technique proposed in Japanese Patent No. 97 has a drawback in that the fluorine compound used is relatively expensive, and the conventional technique proposed in US Pat. I am not satisfied with the effect. Accordingly, an object of the present invention is to provide a paperboard surface treatment method that can effectively eliminate the drawbacks inherent in recycled paperboard by using a different chemical from the above-described conventional technology. is there.

[0006]

According to a first method proposed by the present invention, recycled pulp from waste paper is treated with an aqueous solution of a substituted succinic acid water-soluble salt having an alkyl or alkenyl group having 12 to 21 carbon atoms. The second method is characterized by treating paperboard as a raw material. The second method uses recycled pulp from waste paper in an aqueous solution containing a mixture of the above-mentioned substituted succinic acid water-soluble salt and an acrylamide polymer. It is characterized by processing paperboard. The third method is characterized in that paperboard made from recycled pulp from waste paper is treated with an aqueous solution containing a mixture of the above-mentioned water-soluble salt of substituted succinic acid and a vinyl alcohol-based polymer. .

[0007] To make sure, the Japanese Patent Publication No. 60-101
No. 60 teaches a paper processing method using a mixed aqueous solution of an alkenyl succinate and a polyacrylamide-based material as in the present invention. However, this method uses alkenyl succinate, which was previously used as an internal sizing agent, as a surface sizing agent in order to more effectively exert the sizing effect of the alkenyl succinate (however, The papermaking must contain an aluminum salt such as a sulfuric acid band), and a polyacrylamide-based substance is mixed with the paper to simultaneously improve the surface strength of the paper. Therefore, it cannot be inferred from the description in the publication that the problems inherent in paperboard prepared by recycling waste paper can be solved by the combined use of an alkenyl succinate and a polyacrylamide-based substance.

Further, Japanese Patent Publication No. 63-58960 discloses an alkanoyl monoalkenyl succinate having an alkenyl group having 10 to 16 carbon atoms when producing a coated paper.
It is disclosed that if a luamine salt is incorporated into a coating composition, the coated paper can be released from a coating device and a drying device in a good manner, but solves a problem unique to waste paper-containing paperboard. There is nothing to teach about things.

The water-soluble substituted succinic acid salt having an alkyl group or an alkenyl group having 12 to 21 carbon atoms used in the present invention is an oligomer of α-olefin or internal olefin, for example, an oligomer of propylene or butene, and an oligomer of propylene or butene. Manufactured by saponifying an addition reaction product with maleic acid or a hydrogenated product thereof with an alkali metal hydroxide, aqueous ammonia, an alkylamine, an alkanolamine or the like, preferably with an alkali metal hydroxide or aqueous ammonia. . If the number of carbon atoms of the substituent of the substituted succinic acid water-soluble salt is less than 12, the intended anti-adhesion effect cannot be obtained, and if it exceeds 21, the solubility of the succinate in water is reduced.

The acrylamide polymer of the present invention is prepared by homopolymerizing acrylamide in the presence of a polymerization initiator according to a conventional method, or a monomer copolymerizable with acrylamide, for example, acrylic acid, methacrylic acid, itaconic acid. , Maleic acid, acrylic acid ester, methacrylic acid ester and the like, and acrylamide. As the polymerization initiator in this case, hydrogen peroxide, potassium persulfate, ammonium persulfate, peroxide of alkyl hydroperoxide, any redox initiator composed of a combination of these with a reducing agent can be used. It is.

The acrylamide-based polymer used in the present invention is preferably water-soluble, and nonionic acrylamide-based polymers are particularly preferred because they excel in dilution stability.

As the vinyl alcohol polymer of the present invention, any polyvinyl alcohol prepared by completely or partially saponifying polyvinyl acetate can be used.

In the paperboard processing method of the present invention, when a substituted succinic acid water-soluble salt is used alone as a processing agent,
This is dissolved in water to obtain an aqueous solution having a concentration suitable for impregnation, application or spraying, and the aqueous solution is used in an amount of 0.03 to 0.35 g / m2.
It is preferable to impregnate, coat or spray paperboard with a coating amount in the range of ² (solid content). The substituted succinic acid water-soluble salt used in the present invention imparts a very good anti-adhesion effect to the paperboard, but has a high permeability to the inside of the paperboard, so that when the coating amount is increased, the strength of the paperboard decreases. I am worried. Therefore, the upper limit of the coating amount of the water-soluble salt of substituted succinic acid should be about 0.35 g / m ² .

When a water-soluble substituted succinic acid salt and an acrylamide polymer are used in combination as a paperboard treating agent, the mixing ratio of the two is determined by the weight ratio of the substituted succinic acid water-soluble salt: acrylamide polymer = 1 to 30. : Selected from the range of 99 to 70 and dissolved in water to form an aqueous solution having a concentration suitable for impregnation, coating or spraying, and applying this aqueous solution in the range of 0.2 to 0.8 g / m ² (in terms of solid content). Preferably, the paperboard is impregnated, coated or sprayed in an effort. Since the acrylamide-based polymer has a film-forming property, by using this in combination with a water-soluble salt of substituted succinic acid, an anti-adhesion effect can be imparted to the paperboard and, at the same time, its surface strength can be improved. However, if the mixing ratio of the substituted succinic acid water-soluble salt is below the above range, a satisfactory anti-adhesion effect cannot be obtained. Not only does the water-soluble salt excessively penetrate and the strength of the paper may be reduced, but also the film forming properties of the acrylamide polymer may be impaired.

When a substituted succinic acid water-soluble salt and a vinyl alcohol-based polymer are used in combination as a paperboard treating agent, the mixing ratio of the substituted succinic acid-soluble salt and the vinyl alcohol-based polymer is determined by weight ratio. = 1 to 40: 99 to 60
And dissolved in water to obtain an aqueous solution having a concentration suitable for impregnation, coating or spraying.
It is preferable to impregnate, apply or spray paperboard with a coating amount in the range of m ² (in terms of solid content). Since vinyl alcohol-based polymers have film-forming properties similar to acrylamide-based polymers, they are used in combination with a substituted succinic acid water-soluble salt to provide an anti-adhesion effect to paperboard, Strength can be improved. However, if the mixing ratio of the substituted succinic acid water-soluble salt is below the above range, a satisfactory anti-adhesion effect cannot be obtained. Not only may the strength of the paper decrease due to excessive penetration of the water-soluble salt, but also the film forming properties of the vinyl alcohol polymer may be impaired.

[0016]

The present invention will be described more specifically with reference to the following examples.

Preparation Examples 1 to 9 of Substituted Succinic Acid Water-Soluble Salts A four-necked flask equipped with a stirrer, thermometer and reflux condenser was charged with 100 g of an internal olefin-maleic anhydride adduct having 16 carbon atoms and 196 g of soft water. After maintaining the internal temperature at 75 ° C, 112 g of a 20% aqueous solution of caustic soda was added dropwise thereto, and the mixture was maintained at 75 to 80 ° C for 2 hours to complete the reaction. A salt was obtained.

The substituted succinic acid water-soluble salts of Preparation Examples 2 to 9 were prepared in the same manner as in Preparation Example 1 except that the kind of the substituted succinic acid, the kind and the amount of the alkali substance for forming a salt were changed as shown in Table 1. An aqueous solution was obtained.

[0019]

[Table 1] Preparation Examples A to D of Acrylamide Polymer A 40% strength aqueous acrylamide solution 125 was placed in a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser tube.
g and 115 g of soft water, and after adjusting the pH to 5, nitrogen gas was introduced to adjust the internal temperature to 25 ° C. Then, 0.13 g of ammonium persulfate and 0.13 g of sodium bisulfite were added to initiate polymerization, and the reaction was carried out at 70 to 80 ° C. for 3 hours.
The acrylamide-based polymer aqueous solution of Preparation Example A shown in the following was obtained.

The acrylamide polymers of Preparation Examples B to D were obtained in the same manner as described above, except that the types of the monomer components and the amounts charged were changed as shown in Table 2. Table 2 shows the properties of each acrylamide polymer component.

[0021]

[Table 2] Example The substituted succinic acid water-soluble salt aqueous solution obtained in Preparation Examples 1 to 9 above, the acrylamide polymer aqueous solution obtained in the above acrylamide polymer Preparation Examples A to D, and vinyl alcohol The solid polymer was mixed with the system polymer so that the weight ratio of each solid content became the ratio shown in Tables 3 and 4, to prepare a chemical solution having a solid content concentration of 2%. This solution was applied to the surface of an untreated jute liner (basis weight 170 g / m ² ) using a roll coater, and then a steam dryer 1.5 k
After drying at g / m ² for 1 minute, a treated paper was obtained. The adhesion and surface paper strength of the obtained treated paper were tested by the following methods.

The reference examples in Table 3 are described in US Pat.
This is an example in which a urea aqueous solution having a concentration of 2% is used as a treatment liquid in accordance with the teaching of JP 23,566.

Adhesion test A commercially available aluminum foil coated with a hot-melt adhesive is prepared, this is superimposed on the surface of the above treated paper, and sealed at a temperature of 85 ° C. using a thermal gradient tester (Toyo Seiki Seisakusho). Adhesion was performed for 2 seconds under the condition of a pressure of 1.6 kg / m ² , and then the aluminum foil was peeled off, and the adhesion of the surface of the jute liner and the degree of peeling were observed according to the following criteria.

：: Not adhered at all X: Surface layer peeled ○: Slightly adhered but no fluff XX: Peeled to middle layer △: Slightly fluffed Surface paper strength test JIS P-8129 (Paper using wax Measurement (using Denison wax).

[0025]

[Table 3]

[Table 4]

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) D21H 11/00-27/42

Claims (10)

(57) [Claims] 1. A paperboard characterized by treating a paperboard made from recycled pulp from waste paper with an aqueous solution of a substituted succinic acid water-soluble salt having an alkyl or alkenyl group having 12 to 21 carbon atoms. Surface treatment method. 2. The coating amount of the substituted water-soluble succinic acid salt on paperboard is 0.03 to 0.35 g / m ^2.
The described method. 3. A paperboard made from recycled pulp from waste paper is treated with an aqueous solution of a mixture of a substituted succinic acid water-soluble salt having an alkyl or alkenyl group having 12 to 21 carbon atoms and an acrylamide polymer. A method for treating the surface of paperboard, which comprises treating. 4. The mixture according to claim 3, wherein the weight ratio of the water-soluble substituted succinic acid salt to the acrylamide polymer is:
4. The method of claim 3, wherein the ratio is in the range of 1-30: 99-70. 5. The method according to claim 3, wherein the amount of the mixture according to claim 3 applied to paperboard is 0.2 to 0.8 g / m ² . 6. The method according to claim 3, wherein the acrylamide polymer is nonionic. 7. An aqueous solution of a mixture of a water-soluble substituted succinic acid salt having an alkyl group or an alkenyl group having 12 to 21 carbon atoms and a vinyl alcohol-based polymer, wherein the paperboard made from recycled pulp from waste paper is used as a raw material. Surface treating method for paperboard, characterized by treating with paper. 8. The method according to claim 7, wherein the weight ratio of the water-soluble substituted succinic acid salt to the vinyl alcohol polymer is in the range of 1 to 40:99 to 60. . 9. The method according to claim 7, wherein the amount of the mixture according to claim 7 applied to paperboard is 0.2 to 0.8 g / m ² . 10. The method according to claim 7, wherein the vinyl alcohol-based polymer is polyvinyl alcohol obtained by completely or partially saponifying vinyl acetate.