JPS6010160B2 - Paper processing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a paper processing method.

Methods of internal sizing of paper using aqueous alkenyl succinate solutions are known. (Japanese Patent Publication No. 40-1565) Alkenyl succinic acid is obtained in petrochemistry by wax cracking or low polymerization of chelate. - It can be easily obtained by heating and reacting an olefin and maleic anhydride in the presence or absence of a polymerization inhibitor. As for rosin, which is the raw material for sizing agents for paper manufacturing, our country is completely dependent on imports, and the price of rosin has recently increased, so alkenyl succinates are used as sizing agents for paper manufacturing. If it were possible, it would be great news for our country. However, the method of internal sizing disclosed in Japanese Patent Publication No. 40-565 was unfortunately found to be unsatisfactory in its effectiveness, according to additional tests by the present inventor, and could not be used as a substitute for rosin sizing. The first object of the present invention is to provide a method for processing paper as a sizing method using alkenyl succinates with satisfactory effect. The sizing method of Tsubaki Kosho 40-565 is to add alkenyl succinate as an internal sizing agent to the raw pulp slurry, then add sulfuric acid band to fix the size, and then make paper to obtain sized paper. Met.

Since this method was not able to obtain a satisfactory size effect as described above, the present inventor conducted research on improving the method and, as a result of the research, decided to make a base paper containing aluminum salts in the first place, contrary to the above method. It was confirmed that a completely satisfactory effect can be achieved by treating this base paper with an alkenyl succinate aqueous solution, and the present invention has been completed. The reason why alkenyl succinate suddenly exhibits a wonderful sizing effect by the treatment method of the present invention, which at first glance is simply a reversal of the order of addition, is 1. In conventional internal sizing, the fixation rate of alkenyl succinate is poor. On the contrary, when using the processing method of the present invention, the retention rate is approximately 100%.

2. When using the processing method of the present invention, the bond between aluminum ions and alkenyl succinate ions is made on the surface of the paper, and as a result, a delicate sizing layer is formed only on the surface layer of the paper.

It is assumed that this is due to the following.

On the other hand, in addition to the above-mentioned size effect (properties that prevent ink from bleeding and improve writing properties), improving the surface strength of paper is a common objective of paper processing.

Improving surface strength is extremely important from the viewpoint of printability. Processing agents commonly used to improve surface strength include starch-based, polyvinyl alcohol-based, and polyacrylamide-based agents, but polyacrylamide-based agents are particularly effective and have recently become popular. is remarkable. As paper processing agents for the purpose of size effect, there are rosin-based, petroleum resin-based, styrene-maleic acid resin-based, etc., which have been widely used in the past.
Now, regarding the base paper, if we are trying to simultaneously achieve the two objectives of improving surface strength and improving size effect through processing of the corrugated paper, we will use a processing agent that aims to improve surface strength and a processing agent that aims to improve size effect. A mixed solution of both processing agents may be used. In this case, if a polyacrylamide-based processing agent is selected as a processing agent for the purpose of improving surface strength, an extremely disadvantageous situation will occur. it is,
Conventional rosin-based, petroleum resin-based,
This is because all styrene-maleic acid resin-based processing agents have poor compatibility with polyacrylamide-based processing agents, so it is impossible to mix the two at a commercial concentration. The present applicant previously discovered that an alkaline aqueous solution of a copolymer of hard-acid vinyl and maleic acid monoester is excellent as a paper processing agent for the purpose of size effect, and that it is also highly compatible with polyacrylamide-based processing agents. We have proposed a versatile processing agent consisting of a mixed composition of these.
(Japanese Patent Publication No. 50-13362) However, the copolymer of highly acidic vinyl and maleic acid monoester has the drawbacks of being relatively expensive and having a slight residual ester odor. A second object of the present invention is to provide a new paper processing method that overcomes the drawbacks of the prior inventions mentioned above. As previously explained, it has been found that very satisfactory sizing effects can be obtained by treating base paper containing aluminum salts with an aqueous solution of alkenyl succinates. The alkenyl succinate aqueous solution has good compatibility with the polyacrylamide treatment agent.

Therefore, it is now clear that the second objective can be completely achieved by treating base paper containing aluminum salts with a treatment agent consisting of a mixed aqueous solution of an alkenyl succinate and a polyacrylamide-based substance. became. In the present invention, it is essential that the base paper to be treated contains aluminum salts, and if the base paper does not contain aluminum salts, the effects of the present invention cannot be achieved.

In the present invention, the amount of aluminum salts to be initially added to the raw material pulp slurry is usually 0.00% for the air-drying bulb.
It is 5 to 5% by weight.

In paper mills, it is extremely important to add about 0.5 to 5% of air-dried pulp sulfuric acid to the raw pulp slurry in order to promote drainage of the web on the paper machine wire and increase the sanding speed. Since it is a commonly used technical means, it is considered that the process of making a base paper containing aluminum salts according to the present invention does not bring any particular economic disadvantage. The alkenylsuccinic acids of the present invention are represented by the general formula R-, where R represents an alkenyl group, and particularly preferred are those in which R has 10 to 14 carbon atoms.

Alkenylsuccinic acid can be obtained very easily by subjecting Q-olefin and maleic anhydride to a heating reaction in the absence of a catalyst or in the presence of a polymerization inhibitor. The polyacrylamide-based material referred to in this specification is most commonly represented by a general formula suitable as a surface treatment agent (where M represents an alkali metal atom, NH4, or an amine group, ×, Y, Z
represents an integer (× and Z include 0) X'X+Y+Z
is below 0.4, and Z/X+Y+Z is 0. It is related to Sasuke.

}.

In addition, polymers of acrylamide and monomers other than those mentioned above (for example, acrylnitride, acrylic ester, methacrylic ester, etc.) are also used, and all of them are anionic or nonionic water-soluble polymers. It is a thing. A comparatively small amount of the alkenyl succinate to the polyacrylamide-based material is sufficient, and a practical weight ratio of 10 to 1% is appropriate. When the blending weight of alkenyl succinate is 10% or more, the improvement of surface strength is inhibited although no further improvement of the size effect is observed, and when it is 1% or less, there is no effect of improving surface strength. Although the values are almost the same, there is a significant decrease in size effect improvement. The reason why a small amount of alkenyl succinate is sufficient is that
Alkenyl succinate forms a delicate sizing layer on the surface layer of paper, and once the size layer is formed on the surface of paper, the sizing effect is only due to the water repellency of the aluminum salt of alkenyl succinate. This is because even if extra alkenyl succinate is attached, the size effect does not increase beyond a certain value and is meaningless. Therefore, when the amount of alkenyl succinate is 10% or less, no difference in surface strength improvement effect is observed in practice compared to when the polyacrylamide treatment agent is used alone. However, the mixed aqueous solution of the two is almost colorless and odorless, and is stable even when stored for a long period of time, with no change observed. In the industrial implementation of the present invention, weak size paper made by adding a small amount of rosin sizing agent and sulfuric acid to the raw pulp slurry can also be used as the base paper.

When applying the treatment agent of the present invention, which is a mixed aqueous solution of an alkenyl succinate and a polyacrylamide-based substance, using a size press, if weak size paper is used as the base paper, the amount of liquid absorbed will decrease and the paper will wrinkle. The paper making speed can be increased without any problems, and the cost of sizing can be greatly reduced and strong sized paper can be produced. Processing is performed by further mixing the aqueous solution of the mixed processing agent of the present invention with other processing agents that can be mixed therewith, such as starch-based processing agents, polyvinyl alcohol-based processing agents, highly acidic pinylene maleic acid monoester copolymers, etc. There is no problem.

The paper processing method of the present invention, which has the following configuration, not only can improve the size effect and surface strength of paper at the same time with just one step of processing, but also improves the size effect and surface strength of paper by using a similar processing agent. It is possible to obtain a significantly superior size effect compared to the polyacrylamide-based material, and to obtain high paper forming surface strength due to the PoIJ acrylamide-based material, and to provide a stable and uniform mixture of the alkenyl succinate and the polyacrylamide-based material. Therefore, it is extremely useful industrially in that it can provide a processing method using a high-performance all-purpose surface finishing agent.

Examples will be described below.

Example '-1 20% alkenylsuccinic acid ammonium salt aqueous solution (Gono 1)' Rho 20% polyacrylamide surface treatment agent aqueous solution (Gono 2) was mixed as shown below and processed as a processing agent. Agent '1) W IO%)
90% (2) (a) 5%'.

) 95th “3) (a) ・% Above.

) 99% Koto 1 dodecenyl succinic anhydride (product name D
Anionic polyacrylamide aqueous solution (trade name: X Coat, Viscosity 200, manufactured by PS Seiko Chemical Industry Co., Ltd.) Both processing agents were completely uniform and had good stability.

High-quality paper of weak size as base paper (60 yen/Makura clay 20%
The above processing agents (11, ■, and '3' were each diluted to 1% of the active ingredient) using a roll coater. After coating, the paper to be treated was dried in a steam dryer (110° C.) for 2 minutes, and after humidity control for 2 hours, it was subjected to a test and the results shown in Table 4 were obtained.

Table 4

Claims (1)

[Claims] 1. A paper processing method characterized by treating base paper containing aluminum salts using a processing agent consisting of a mixed aqueous solution of an alkenyl succinate and a polyacrylamide-based substance.