JPS5930840B2 - Manufacturing method of paper sizing agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Recently, as industrial water regulations and factory wastewater regulations have been strictly enforced, the quality of water used in paper mills in our country has been decreasing year by year.

If the quality of water decreases and the concentration of salts in the water increases, the effectiveness of paper sizing agents becomes significantly poorer, so the deterioration of the quality of the water has become a serious problem in the industry. Under these circumstances, new emulsion-type paper sizing agents that can exhibit good sizing effects even when the concentration of salts in water increases have recently attracted attention. According to U.S. Pat. No. 3,565,755, this new emulsifying type sizing agent is produced by reacting rosin with maleic anhydride or fumaric acid, dissolving the resulting reacted resin in a water-immiscible solvent such as benzene, and then reacting the resin with maleic anhydride or fumaric acid. Manufactured by emulsifying and dispersing in water using enough alkali to saponify 0.5 to 20% of the resin, stabilizing the resulting emulsion using a special high-pressure emulsifier, and then distilling off the solvent. It is something that will be done.

This emulsion is very stable and differs from old emulsion-type paper sizing agents in that the emulsion particles are ultrafine. Currently, in our country, an aqueous solution-type reinforced rosin sizing agent for papermaking is commonly used, which is made by completely saponifying a reaction product of rosin and maleic anhydride with an alkali to form a soap solution.

When performing sizing using this, when a sizing agent is added to the pulp slurry, first fine rosin particles are generated by hydrolysis of the sizing agent, and when sulfuric acid is added to this, its fixing action causes Size particles settle into the microstructure of the fibers and are sized. It is thought that if salts are present in the water at this time, the soap solution will coagulate and the size of the particles will become huge, thereby eliminating the size effect. When using a new emulsifying type sizing agent, the emulsified particles are ultra-fine and have sufficient stability, so they maintain their fine particle shape and fix the size without being affected by the agglomeration effect caused by salts. It would be possible to do this. The new emulsifying type sizing agent has various other advantages, but as mentioned above, its production requires the use of a solvent, which not only makes the process complicated, but also makes it difficult to use high-pressure emulsifiers. There is still room for improvement in that such special equipment is required. The present inventor previously published Japanese Patent Publication No. 52-25444
In this issue, we proposed a paper sizing agent consisting of an emulsion of a reaction product of rosin and an unsaturated monobasic acid.

The most commonly used fortified rosin sizing agent in our country is the rosin containing maleic anhydride, fumaric acid, etc.
It uses a resin reacted with an unsaturated dibasic acid. The reason why the present inventor used an unsaturated monobasic acid such as acrylic acid in place of these unsaturated dibasic acids is as follows. In other words, conventional strengthened rosin sizing agents are made by reacting rosin with an unsaturated dibasic acid equivalent to about 5% of the weight of the rosin, and then saponifying the reaction product using an alkali in an amount equivalent to the saponification equivalent. , made with a soap aqueous solution.

When rosin is reacted with an unsaturated acid, an equimolar adduct of the two is produced in any case. Therefore, in the case of the above-mentioned reinforced rosin size agent, the unsaturated dibasic acid is additionally bonded to approximately 1/6 of the total amount of rosin, and the remaining approximately 5/6 of the rosin remains unreacted. From the point of view of the size effect, the best results can be obtained at this level of addition ratio, and if more equimolar adducts are present, the size effect is rather reduced. This is because in this case, the equimolar adduct itself becomes a tribasic acid and has too strong hydrophilicity, and no size effect can be expected from the equimolar adduct itself. However, equimolar adducts of rosin and unsaturated acids have an excellent dispersant effect on rosin, so if a small amount of equimolar adducts are mixed in rosin, the equimolar adducts will disintegrate the rosin particles during sizing. By making it finer and more uniform, it suddenly produces an excellent size effect.
However, even with this reinforced rosin sizing agent, deterioration of the sizing effect cannot be avoided if the salt concentration in the water is high. This is thought to be due not only to the fact that the above-mentioned reinforced rosin sizing agent is a soap type, so it cannot escape the aggregation effect caused by salts, but also because the amount of the equimolar adduct, which should act as a dispersant, is too small. It will be done. On the other hand, in the case of the reaction product of rosin and acrylic acid, the equimolar addition product not only exerts an excellent dispersant effect on rosin and contributes to the size effect, but also Unlike the case of an equimolar adduct of rosin and an unsaturated dibasic acid, the adduct itself has water repellency, and therefore exhibits an excellent size effect even when used alone. Therefore, in the case of a reaction product of rosin and acrylic acid, even if an equimolar adduct thereof is present in a large amount, no phenomenon in which the size effect is reduced is observed. In addition, the reaction product of rosin and acrylic acid has excellent emulsifying properties and is capable of producing a stable emulsion.
The present inventor has developed an acidic resin obtained by reacting rosin with an unsaturated monobasic acid such as acrylic acid corresponding to 7% or more of its weight (in this case, approximately 1/3 or more of the total amount of rosin is an equimolar adduct). It was confirmed that good sizing effects can be obtained when the emulsion of
The invention of No. 2-25444 was completed. In the invention disclosed in Japanese Patent Publication No. 52-25444, the present inventor used an alkali corresponding to approximately 20% or less of the saponification equivalent of the reaction product of rosin and acrylic acid as a saponifying agent, and used casein as a protective colloid. It was clarified that a stable emulsion can be easily made by this method. However, the emulsion in this case still does not have the ultra-fine particle nature of the emulsified particles compared to the new emulsion-type paper sizing agent disclosed in U.S. Pat. No. 3,565,755, and therefore cannot be used as a sizing agent. In terms of performance, it was inevitable that they would be slightly inferior. In view of the above, the present invention has been made by improving the invention of Japanese Patent Publication No. 52-25444 to produce the above-mentioned new emulsifier in a simple process without using a solvent and without special manufacturing equipment. It is an object of the present invention to provide a method for producing a sizing agent for paper manufacturing that is comparable in performance to conventional sizing agents for paper manufacturing. As a result of many years of research, the present inventor discovered that when N-dialkylamino alcohol is used as a saponifying agent in emulsifying a rosin resin, the emulsified particles become extremely fine and their stability is significantly improved.

This is thought to be because soaps obtained using N-dialkylamino alcohols are extremely suitable as emulsifiers for rosin, and the solvent action unique to N-dialkylamino alcohols also contributes to emulsification. Industrially, it is more convenient to use N-dialkylamino alcohol in combination with other alkalis than to use it alone as a saponifying agent. The present inventor made this discovery in
-25444, we have here developed a method for producing a sizing agent that can completely achieve the intended purpose. That is, the present invention involves a step of producing a paper sizing agent by emulsifying and dispersing an acidic resin obtained by reacting rosin with acrylic acid using a saponifying agent, casein, and water.
For paper manufacturing, characterized in that the saponifying agent is an N-dialkylamino alcohol corresponding to 5 to 20% of the saponification equivalent of the acidic resin, and optionally an alkali corresponding to 7% or less of the saponification equivalent of the acidic resin. This relates to a method for producing a sizing agent.

Therefore, in the present invention, the amount of acrylic acid to be reacted with the rosin is preferably 7% or more (but not more than the equivalent weight of the rosin) based on the weight of the rosin. The amount of N-dialkylamino alcohol used as a saponifying agent in the present invention is required to be 5 to 20% of the saponification equivalent of the acidic resin.
Within this range, it can be changed appropriately depending on the amount of alkali used. However, when the amount of N-dialkylamino alcohol is less than 5%, the effect of the present invention is not sufficient, and on the other hand, when it is more than 20%, the emulsion stability becomes poor. As the industrially usable N-dialkylamino alcohol, N-dimethylaminoethanol and N-diethylaminoethanol are suitable. Although the purpose of the present invention can be achieved by using N-dialkylamino alcohol alone, in industrial implementation, it is more convenient to use an alkali together from the viewpoint of emulsification operation and economically. In this case, the amount of alkali used must be 7% or less of the saponification equivalent of the acidic resin. If the amount used is 7% or more, the unique characteristics of N-dialkylamino alcohol acting as a saponifying agent cannot be fully utilized.

The paper sizing agent of the present invention can exhibit sufficiently excellent sizing effects even under normal papermaking conditions, but as will be clarified in the examples later, when the salt concentration in the water is high, It exhibits excellent sizing effects that are incomparable to rosin sizing agents.

Furthermore, since the paper sizing agent of the present invention is an emulsion-type sizing agent, it is possible to effectively fix the size by using it in combination with an organic cationic fixing agent, and this has the advantage that it can be used for so-called neutral sizing. has. Examples of the present invention will be described below, but these examples do not limit the present invention.

Example 1 Rosin 1100k9 was charged in a reaction pot (with a thermometer, reflux condenser, and stirrer), and after heating and melting, hydroquinone 2.2k9 and 98% acrylic acid 140k9 were added thereto, and the mixture was heated at 130°C. 3 hours, 14
The reaction was carried out for 2 hours at 0°C and further for 4 hours at 190-200°C, and the 12.5% acrylic acid-added rosin (resin A) was reacted at 121°C.
I gained 7kg.

This resin A had a melting point of 82° C. and an acid value of 232. The above resin A6OOO7 was charged into a reaction vessel (equipped with a thermometer, a Ribrax condenser, and a stirrer), heated and melted, and 111 t of a 25% KOH aqueous solution (corresponding to 2% of the saponification equivalent) was added at 130°C.

Next, 10% casein ammonia aqueous solution-39007 (casein 3907 was mixed with 28% ammonia water 58r and water 344
2V) was gradually added. After the addition was completed, the internal temperature was 90-102°C. After stirring at this temperature for 30 minutes, N-dimethylaminoethanol 2467 (corresponding to 11% of the saponification equivalent) was added at 85 to 98°C, and the mixture was reacted with stirring at this temperature for 60 minutes. After that, about 80℃
By gradually adding warm water to emulsify, the solid content is reduced to 3.
18.5 kg of 5.6%, pH 6.9 paper sizing agent
yield was obtained. Example 2 Rosin 8007 was charged into an 11-volume four-bottle flask (with thermometer, Ribrax condenser, and stirrer), and after heating and melting, hydroquinone 1.67 and 98% acrylic acid 1237 were added thereto, and the mixture was heated at 130°C for 3 hours. The reaction was carried out at 140°C for 2 hours and then at 190/°C for 4 hours to obtain 913y of 15% acrylic acid-added rosin (resin B).

The acid value of this resin B was 238. The above resin BIO
Pour O7 into a 500 cc four-tube flask (with a thermometer, Ribrax condenser, and stirrer), melt it by heating, and prepare N-dimethylaminoethanol7 at 120-1?0°C.
．． 1 t (corresponding to 18.8% of the saponification equivalent) was added.

After the addition was completed, the reaction was carried out at 120 to 130°C for 30 minutes.
Next, after gradually adding 10% casein ammonia aqueous solution 80 (I7), stirring was continued at 90 to 100°C for 30 minutes, and then warm water at about 80°C was gradually added to emulsify. In this way, paper with a solid content of 37% was produced. Example 3 Rosin 8007 was charged into an 11-volume four-volume flask (equipped with a thermometer, Ribrax condenser, and stirrer), and after heating and melting, hydroquinone 1.67 and 98% acrylic were added to the sizing agent. 82y of acid was added and reacted at 130°C for 3 hours, at 140°C for 2 hours, and further at 190°C for 4 hours to obtain 879y of 10% acrylic acid-added rosin (resin C).

The acid value of this resin C was 223. The above resin ClO
Ot was charged into a 500 cc capacity Yotsuro flask (with a thermometer, Ribrax condenser, and stirrer), heated and melted, and 4.4 f of a 25% KO aqueous solution (equivalent to 5% of the saponification equivalent) was added at 140 to 160°C. Then, a 10% caseinate ammonia aqueous solution was gradually added.

After the addition was completed, the internal temperature was 90-102°C. After stirring at this temperature for 30 minutes, 3.55 f of N-dimethylaminoethanol (corresponding to 10% of the saponification equivalent) was heated to 85-98°C.
was added, and the mixture was stirred and reacted at this temperature for 60 minutes. Next, by gradually adding warm water of about 80°C to emulsify, 1
A paper sizing agent with a yield of 300 tons and a solid content of 36% was obtained.
Test Example Using the paper-making sizing agents of the present invention obtained in Examples 1 to 3 and a commercially available reinforced rosin sizing agent (trade name: Coropal S-20 manufactured by Seiko Kagaku), a sizing effect test was conducted on hand-made paper.

(1) Dilute raw material pulp (L-B'KP Canadian Standard Freeness 414CC) with seawater (1 part seawater: 6 parts pure water)
A pulp slurry with a concentration of 2.4% in terms of air-dried pulp was prepared using a mixture of The pH of the pulp slurry was set to 4.5.

Using a hand paper tester (trade name: TAPPI Standard Sheet Machine, manufactured by Toyo Seiki), this was tested at 60f/T according to the usual method.
A hand-sized paper corresponding to I was prepared.

Claims (1)

[Claims] 1. In the step of producing a paper sizing agent by emulsifying and dispersing an acidic resin obtained by reacting rosin with acrylic acid using a saponifying agent, casein, and water, 5 to 50% of the saponification equivalent of the acidic resin is used as the saponifying agent. A method for producing a paper sizing agent, which comprises using N-dialkylamino alcohol corresponding to 20% and, optionally, an alkali corresponding to 7% or less of the saponification equivalent of the acidic resin.