JP2539825B2 - Paper sizing agent and paper sizing method using the sizing agent - Google Patents

Description

The present invention relates to a novel paper sizing agent and a paper sizing method using the sizing agent. More specifically, the present invention relates to a sizing agent suitable for neutral papermaking and a paper sizing method using the sizing agent.

[Prior Art] In recent years, in order to put into practical use a neutral papermaking method that takes into consideration the adverse effects of acidic papermaking, such as deterioration of papermaking machines and deterioration of papermaking over time, neutralizing papermaking sizing agents or neutralizing papermaking sizing Various compounds used in the method have been investigated. For example, alkenyl succinic anhydride-based sizing agents and alkyl ketene dimer-based sizing agents are used as neutral papermaking sizing agents.

However, among the sizing agents, alkenyl succinic anhydride-based sizing agents cannot be stored in the state of an aqueous dispersion because they have poor hydrolysis stability, so they must be emulsified and dispersed immediately before the paper making step, and workability is improved. It has the drawback of being bad. Further, the alkyl ketene dimer type sizing agent has a disadvantage that the sizing effect immediately after paper making is inferior because the sizing effect rises slowly. Therefore, there is a demand for the development of a new neutral papermaking sizing agent that can solve such problems.

[Problems to be Solved by the Invention] Therefore, the present inventors have not provided a new and useful paper sizing agent for neutral papermaking. That is, the object of the present invention does not have the above-mentioned drawbacks,
An object of the present invention is to provide a paper sizing agent which is satisfactory in terms of both size effect and workability.

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have found that a polybasic carboxylic acid containing an α-hydroxy group and a monohydric alcohol or 1 When a specific esterified product or amidated product composed of a divalent amine is used, it is possible to provide a relatively inexpensive neutral papermaking sizing agent that exhibits excellent sizing effect and dispersion stability and It has been found that the use of an agent can provide a good paper sizing method in that calcium carbonate, which is an inexpensive filler, can be used, and has completed the present invention.

That is, the present invention relates to a monobasic or polybasic carboxylic acid (A) having at least one α-hydroxy group for a carboxyl group, a monohydric alkyl alcohol having at least 8 carbon atoms, and at least 8 A monovalent alkenyl alcohol having carbon atoms, a monovalent mono- or dialkylamine having one hydrophobic substituent having at least 8 carbon atoms and a monovalent alkenyl alcohol having one hydrophobic substituent having at least 8 carbon atoms At least one selected from the group consisting of mono- or dialkenylamines
A paper-based sizing agent characterized by comprising a hydrophobic fully esterified product and / or a hydrophobic fully amidated compound consisting of a compound (B) of the present invention as an active ingredient, and a paper sizing method using the sizing agent Regarding

[Examples] The paper sizing agent of the present invention comprises a monobasic or polybasic carboxylic acid having at least one α-hydroxy group with respect to a carboxyl group (hereinafter referred to as component (A)),
Monohydric alkyl alcohols having at least 8 carbon atoms, monohydric alkenyl alcohols having at least 8 carbon atoms, monohydric mono- or dialkylamines in which one hydrophobic substituent has at least 8 carbon atoms and 1 At least one compound selected from the group consisting of monovalent mono- or dialkenylamines in which one hydrophobic substituent has at least 8 carbon atoms (hereinafter referred to as (B)
(Hereinafter referred to as “component”) containing a hydrophobic complete esterified product and / or a hydrophobic complete amidated product as an active ingredient.

Examples of the monobasic carboxylic acid having at least one α-hydroxy group for the carboxyl group used in the component (A) include, for example, α-hydroxystearic acid, α-hydroxypalmitic acid, α-hydroxymyristic acid and α. -Hydroxybehenic acid and the like. Also, at least one α-for the carboxyl group
Examples of the polybasic carboxylic acid having a hydroxy group include malic acid, tartaric acid, citric acid, tartronic acid,
Examples include α-oxyglutanic acid. Among the above carboxylic acids, malic acid, tartaric acid and citric acid are preferable in terms of price.

The monovalent alkyl alcohol or alkenyl alcohol having at least 8 carbon atoms (hereinafter referred to as the component (B-1)) used in the present invention may be linear or branched, and Specific examples include 2-ethylhexyl alcohol, octyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, behenyl alcohol, oleyl alcohol and the like. A monovalent mono- or dialkylamine or a monovalent mono- or dialkenylamine having one hydrophobic substituent having at least 8 carbon atoms (hereinafter referred to as (B-
The component 2)) may be linear or branched, and specific examples thereof include 2-
Examples thereof include ethylhexylamine, laurylamine, myristylamine, palmitylamine, stearylamine, behenylamine, oleylamine and their corresponding dialkyl or dialkenylamines.

The hydrophobic complete esterification product and / or hydrophobic complete amidation product (hereinafter referred to as reaction product (C)), which is the active ingredient of the sizing agent of the present invention, is the above-mentioned component (A) and component (B-1) and / or Alternatively, the component (B-2) can be easily produced by dehydration condensation using known esterification or amidation conditions. That is, after the components (A) and (B) have been charged into the reaction vessel, the boiling point of the component (B) is taken into consideration, and the temperature is set to 80 to 200 ° C. under normal pressure or reduced pressure.
It suffices to conduct dehydration condensation while stirring for ~ 24 hours. In the reaction, a known basic or acidic catalyst can be used, and further, a solvent such as benzene, toluene or xylene can be used for dehydration under azeotropic distillation.
Here, the charging ratio of the component (A) and the component (B) is usually adjusted so that the equivalent ratio of the hydroxyl group or amino group of the component (B) to the carboxyl group of the component (A) is 1. . When a lower alcohol ester or amide of a polybasic carboxylic acid is used as a starting material and a transesterification reaction or an amide exchange reaction with the component (B) is adopted, an exchange reaction catalyst such as di-n-oxide can be used.
The reaction product (C) can be produced by employing a known method in the presence of -butyltin, p-toluenesulfonic acid and the like. At this time, the charging ratio of the lower ester of the polybasic carboxylic acid or the lower amide of the polybasic carboxylic acid and the component (B) is the same as the specific charging ratio of the component (A) and the component (B). is there.

In addition, an ester composed of the component (A) and a lower monohydric alcohol or an amide composed of the component (A) and a lower monovalent amine is used as a starting material, and the component (B-1) or the component (B-2) is used. It is also possible to obtain a reaction product (C), that is, a hydrophobic complete esterified product or a hydrophobic complete amidated product by transesterification or transamidation reaction with.

As a method for dispersing the reaction product (C) in water, both a so-called high pressure emulsification method and an inversion method can be adopted. That is, in the case of the high pressure emulsification method, the reaction product (C) forming the dispersed phase is melted or dissolved in a solvent such as benzene or toluene, and then an emulsifier and warm water are mixed to obtain a high pressure emulsification. After emulsification using a machine, the aqueous dispersion can be obtained as it is or by distilling off the solvent. Further, in the case of the inversion method, after thoroughly kneading the solid content and the emulsifier, warm water is gradually added dropwise under melting and stirring to invert the phase to form an aqueous dispersion without using any solvent. You can get it.

As the emulsifier that can be used in the above method, various surfactants, protective colloids and the like can be used without particular limitation. As the surfactant, an alkylbenzene sulfonate,
Anionic emulsifiers such as alkyl sulfates, rosin soap naphthalene sulfonate sodium soda formalin condensates; nonionic emulsifiers such as polyethylene oxide and polypropylene oxide; polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene alkylphenyl ether sulfonates, poly Examples thereof include nonionic-anionic emulsifiers such as sulfosuccinate of oxyethylene alkyl phenyl ether, polyoxyethylene distyryl phenyl ether sulfate, and sulfosuccinate of polyoxyethylene distyryl phenyl ether. Examples of protective colloids include casein, lecithin, polyvinyl alcohol, and various modified starches. Further, a fixing agent described later can be used in advance during emulsification. According to the above method, an aqueous dispersion having a solid content of 10 to 50% can usually be easily produced, and it can be used after diluting it if necessary.

The application of the sizing agent obtained above to a neutral papermaking method will be described below.

The aqueous dispersion which is the paper sizing agent of the present invention is added to the pulp slurry together with the filler, the fixing agent, the paper strength enhancer and the like. The amount of the aqueous dispersion added is usually 0.01 to 2.0.
% (Solid content conversion), preferably 0.1 to 1.0% by weight. If the amount is less than 0.01% by weight, a sufficient size effect is difficult to be exhibited, and if the amount exceeds 2.0% by weight, it is not desirable to add it excessively, and therefore both are not preferable. Further, the filler that can be used is not particularly limited and any conventionally known filler can be used, and further, calcium carbonate, which cannot be used in the conventional acidic papermaking method, can be suitably used. , There is an advantage that can greatly contribute to the reduction of the papermaking price.

As the fixing agent, various known materials used for neutral sizing agents such as alkyl ketene dimer and alkenyl succinic anhydride can be used as they are. For example, cationic starch, epichlorohydrin modified polyamide polyamine resin, epichlorohydrin modified dicyandiamide resin, epichlorohydrin modified styrene-dimethylaminoethyl methacrylate copolymer, Mannich modified polyacrylamide, acrylamide-dimethylaminoethyl methacrylate copolymer Examples thereof include coalesced products, Hoffman degradation products of polyacrylamide, and copolymers of dialkyldiallylammonium chloride and sulfur dioxide. Further, the sulfuric acid band used in the acidic papermaking method may be used in a small amount so long as the papermaking pH is not so lowered.

Although the sizing agent of the present invention can exhibit excellent sizing performance by itself, a known neutral sizing agent, for example, epichlorohydrin modified product of styrene-dimethylaminoethyl methacrylate copolymer, alkenyl succinic anhydride, alkyl ketene dimer. It is also possible to use an epichlorohydrin-modified product of a fatty acid-polyalkylpolyamine condensate in combination.

In the present invention, the pH at the time of papermaking can be widely used from the acidic region of usually 3 to 9 to the alkaline region, and particularly, it can be suitably used within the range of pH 6 to 9 and can exert an excellent size effect. Further, the sizing agent of the present invention can also be used as a surface sizing agent.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to these Examples. In the examples, all parts and% are by weight unless otherwise specified.

Examples 1 to 9 100 parts of a reaction product obtained by reacting the components (A) and (B) shown in Table 1 with 100 parts of toluene and an emulsifier (polyoxyethylene alkylphenyl ether, Daiichi Kogyo) Pharmaceutical Co., Ltd., trade name "Neugen EA-120") 12
Parts, then heated and dissolved, 9800 parts of warm water was added, and the mixture was stirred at high speed to prepare an aqueous dispersion having a solid content concentration of 1%.

Using the thus obtained aqueous dispersion which is the sizing agent for neutral papermaking of the present invention, papermaking was performed according to the following paper sizing method, and the sizing performance was examined.

(Paper sizing method) Pulp (L-BKP) is Canadian standard
It was beaten to a freeness of 450 ml to give a 1% slurry. Calcium carbonate (Sankyo Seiko Co., Ltd.) as a filler in the slurry
Brand name "Escalon # 100" manufactured by Okamoto Co., Ltd. is added to pulp 20% in terms of solid content, aluminum sulfate 1%, cationized starch (manufactured by Oji National Co., Ltd., brand name "Cato 1").
5 ") 1%, then 0.4% of the neutral papermaking sizing agent obtained above was added to the pulp, and a filler retention agent (manufactured by Allied Colloid Limited, trade name" Percoll
47 ") was added 0.02% and uniformly dispersed. At this time, the pH of the pulp slurry was 7.8. The resulting slurry is weighed 70 using the Tappi Standard Sheet Machine.
Paper was made so that it would be g / m ² . The wet paper obtained was then dehydrated by compression, dried at 100 ° C for 1 minute, and conditioned at a relative humidity of 65% for 24 hours. Then, according to JIS P 8122, each size degree (second ) Was measured. The measurement results are shown in Table 1.

Comparative Example 1 and Comparative Example 2 An aqueous dispersion having a concentration of 1% was prepared in the same manner as in Example 1 except that the reaction products obtained by reacting the components (A) and (B) shown in Table 1 were used. Was adjusted.

Using the sizing agent obtained above, papermaking was performed in the same manner as in Examples 1 to 9 to measure the sizing degree. The measurement results are shown in Table 1.

Further, the sizing agents obtained in Examples 1 to 9 were all emulsified and allowed to stand for 1 day, and the sizing effect was examined again. As a result, the sizing degree was almost the same as that in the initial stage.

[Effects of the Invention] As described in detail above, the paper sizing agent of the present invention has a pH of 6-9.
In the neutral region, it exerts an extremely excellent size effect, and has the effect of good storage stability (hydrolysis stability).

Further, the paper sizing method of the present invention does not have a phenomenon of rising of the size effect of the mature paper as in the case of the paper sizing method using the alkyl ketene dimer sizing agent, and the paper sizing method using the alkenyl succinic anhydride sizing agent Since it does not require an emulsification operation just before paper making, it is a method with high industrial value.

Claims (7)

(57) [Claims] 1. A monobasic or polybasic carboxylic acid (A) having at least one α-hydroxy group for a carboxyl group, and 1 having at least 8 carbon atoms.
A monovalent alkyl alcohol, a monovalent alkenyl alcohol having at least 8 carbon atoms, a monovalent mono- or dialkylamine having one hydrophobic substituent having at least 8 carbon atoms and at least eight hydrophobic substituents Having a hydrophobic complete esterified product and / or a hydrophobic complete amidated product, which is composed of at least one compound (B) selected from the group consisting of monovalent mono- or dialkenylamines having a carbon atom of A sizing agent for paper. 2. The paper sizing agent according to claim 1, wherein the monobasic carboxylic acid is at least one selected from α-hydroxystearic acid, α-hydroxymyristic acid and α-hydroxypalmitic acid. . 3. The paper sizing agent according to claim 1, wherein the polybasic carboxylic acid is at least one selected from malic acid, tartaric acid and citric acid. 4. The paper sizing agent according to claim 1, wherein the monohydric alkyl alcohol having at least 8 carbon atoms is palmityl alcohol and / or stearyl alcohol. 5. The paper sizing agent according to claim 1, wherein the hydrophobic complete esterified product and / or the hydrophobic complete amidated product is dispersed in water. 6. A monobasic carboxylic acid (A) having at least one α-hydroxy group with respect to a carboxyl group.
And a monohydric alkyl alcohol having at least 8 carbon atoms, a monohydric alkenyl alcohol having at least 8 carbon atoms, and at least 8 hydrophobic substituents.
At least one compound selected from the group consisting of monovalent mono- or dialkylamines having 6 carbon atoms and monovalent mono- or dialkenylamines having one hydrophobic substituent having at least 8 carbon atoms ( A paper sizing method, which comprises using a paper sizing agent containing a hydrophobic completely esterified product and / or a hydrophobic completely amidated product of B) as an active ingredient. 7. The paper sizing method according to claim 6, wherein the paper sizing agent is used in a neutral range of pH 6-9.