JPH0379480B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a novel neutral paper sizing method. Conventional Technology Recently, in order to put a neutral paper making method into practical use, taking into account the negative effects of acidic paper making, such as deterioration of paper making machines and deterioration of paper over time, neutral paper sizing agents or neutral paper sizing methods have been developed. Regarding this, various compounds are being studied. For example, alkenyl succinic anhydride and alkyl ketene dimer are used as neutral paper sizing agents. However, among these, alkenyl succinic anhydride-based sizing agents have poor hydrolytic stability and cannot be stored in the form of an aqueous dispersion, so they must be emulsified and dispersed immediately before the papermaking stage, resulting in poor workability. It has drawbacks and the disadvantage of high price. In addition, alkyl ketene dimer sizing agents have the disadvantage that the sizing effect is inferior immediately after paper making because the sizing effect takes a long time to develop.In addition, they are more expensive than alkenyl succinic anhydride sizing agents, leading to increased costs. There is a problem. By the way, in acidic papermaking methods, emulsion-type sizing agents obtained by dispersing rosin or reinforced rosin using a soap-type sizing agent or dispersant made by saponifying rosin or the like with an alkali metal hydroxide have conventionally been widely used. There is. When these sizing agents are used as neutral paper-making sizing agents, they do not exhibit good sizing effects, so it is necessary to use sulfuric acid as a fixing agent and use them in an acidic region of less than PH6. The reason why the size effect is inferior in neutral conditions is still not clear, but it is presumed that at pH 6 or higher, a portion of the rosin or reinforced rosin migrates into water and the yield in the pulp decreases. Also,
Another problem with the acidic papermaking method is that calcium carbonate, which is an inexpensive filler, cannot be used. Problems to be Solved by the Invention It is an object of the present invention to provide a new and effective sizing method for neutral papermaking. The present inventors focused on rosin-based compounds, which have conventionally been considered unusable for neutral papermaking, but have a proven track record in acidic papermaking methods, and applied some technical means to this compound to There are no disadvantages caused by neutral paper sizing agents, and the size effect, workability,
The aim is to develop a neutral paper sizing method that is satisfactory in terms of cost. Means for Solving the Problems As a result of intensive research, the present inventors surprisingly found that an aqueous dispersion containing a specific rosin ester was found.
It exhibits an excellent size effect in the neutral range of pH 6 or above, has good storage stability as an aqueous dispersion and can be used as is for paper making, making it easy to work with, is relatively inexpensive, and can use calcium carbonate. Together with this, we have discovered that paper manufacturing costs can be reduced. The present invention was completed based on these new findings. That is, in the present invention, rosin and at least one of a trihydric alcohol and a tetrahydric alcohol consisting of C, H, and O are heated at a charging ratio such that the ratio of hydroxyl group equivalent to carboxyl group equivalent is 0.2 to 1.5. A neutral paper sizing method characterized in that a sizing agent in which the resulting reaction product is dispersed in water is added to a pulp slurry, and the method is used in a neutral pH range of 6 to 9 without adding sulfate. . As mentioned above, in the sizing agent used in the present invention, the dispersed phase contains rosin and at least one of trihydric alcohol and tetrahydric alcohol consisting of C, H, and O.
It is formed from a reaction product obtained by charging these in a specific ratio and heating them, and the reaction product is obtained as the polyhydric alcohol ester of rosin or a mixture of this and rosin. In this specification, rosin refers to gum rosin,
It refers to tall oil rosin, udon rosin, and modified products thereof, and examples of the modified products include hydrogenated rosin, disproportionated rosin, and formaldehyde-modified rosin. In addition, the above esters include rosin and C,
It is an esterified product produced by dehydration condensation with at least one of a trihydric alcohol and a tetrahydric alcohol consisting of H and O, and the concept includes completely esterified products and partially esterified products. In the present invention, it is necessary to use at least one type of trihydric alcohol and tetrahydric alcohol consisting of C, H, and O as the polyhydric alcohol. Monohydric alcohol, dihydric alcohol, amino alcohol, etc.
The intended effect of the present invention cannot be obtained. Specifically, glycerin, trimethylolethane, trimethylolpropane, 3-methylpentane-1,3,5-
Examples include trihydric alcohols such as triol and tetrahydric alcohols such as pentaerythritol and diglycerin, and polyhydric alcohols selected from these may be used alone or in combination. The above-mentioned polyhydric alcohol esters of rosin can be produced by subjecting the rosin and the above-mentioned polyhydric alcohols to known esterification conditions. at a temperature of 150 to 300 under normal pressure, reduced pressure, or increased pressure.
The dehydration condensation may be carried out at a temperature of about 30°C for about 3 to 40 hours while stirring. Additionally, during the reaction, if necessary, a solvent such as benzene, toluene, or xylene may be used.
Dehydration can also be carried out azeotropically. Here, the rosin and the polyhydric alcohol have a specific charging ratio, that is, the equivalent ratio of the hydroxyl group of the polyhydric alcohol to the carboxyl group of the rosin [-OH(eq)/-COOH(eq)]. 0.2～
1.5, preferably 0.4 to 1.2. If the equivalent ratio is less than 0.2, the sizing effect of the resulting sizing agent in the neutral region will not be sufficiently improved, which is not preferable. In addition, if the equivalent ratio exceeds 1.5, a large amount of free hydroxyl groups will remain in the polyhydric alcohol ester of the rosin that is produced, so if this is used as a sizing agent, the size will increase due to the remaining hydroxyl groups. This is not preferable because it reduces effectiveness. The reaction product of the above reaction is usually a completely esterified product in which all of the hydroxyl groups of the polyhydric alcohol are esterified with the carboxyl groups of the rosin;
Various mixtures of partially esterified products in which a portion of the hydroxyl groups are esterified and unreacted raw materials,
In the present invention, as long as the reaction mixture is within the range of the above-mentioned equivalent ratio, it can be used as it is as the dispersed phase of the sizing agent. The reaction product usually contains about 20% by weight or more of the completely esterified product and/or partially esterified product based on the solid content. The reaction products include
If necessary, rosins may be further added.
In this case, even after addition, the completely esterified product and/or partially esterified product is 20% by weight in the solid content.
The content is preferably 40% by weight or more, and more preferably 40% by weight or more in consideration of the performance of the resulting sizing agent. If the ratio of these esterified products is less than 20% by weight, it is not preferable because the size effect decreases. The sizing agent used in the present invention can be produced by forming an aqueous dispersion of the above-mentioned reaction product or a mixture thereof with a rosin by a so-called high-pressure emulsification method, an inversion method, or the like. That is, when using high pressure emulsification method,
The above reaction products forming the dispersed phase are mixed with benzene,
It is possible to obtain an aqueous dispersion by dissolving it in a solvent such as toluene, then mixing an emulsifier and warm water thereto, emulsifying it using a high-pressure emulsifier, and then distilling off the solvent. In addition, when using the inversion method, after sufficiently kneading the above reaction products, etc. and the emulsifier, warm water is gradually added dropwise while melting and stirring, and phase inversion is performed to form an aqueous dispersion without using any solvent. can be obtained. As the emulsifier that can be used in the above method, various surfactants, protective colloids, etc. can be used without particular limitation. Examples of the surfactant include anionic emulsifiers such as alkylbenzene sulfonates, alkyl sulfates, and rosin soaps, nonionic emulsifiers such as polyethylene oxide and polypropylene oxide, polyoxyethylene alkyl phenyl ether sulfates,
Nonions such as polyoxyethylene alkyl phenyl ether sulfonate, polyoxyethylene alkyl phenyl ether sulfosuccinate, polyoxyethylene distyrylphenyl ether sulfate, polyoxyethylene distyrylphenyl ether sulfosuccinate, etc. Examples include anionic emulsifiers. Examples of protective colloids include casein, lecithin, polyvinyl alcohol, and various modified starches. Furthermore, a fixing agent, which will be described later, may be added in advance during emulsification. According to the above method, an aqueous dispersion having a solid content concentration of about 10 to 50% by weight can be easily produced, and this can be diluted and used if necessary. Hereinafter, a case will be described in which the sizing agent obtained above is applied to a neutral paper making method. The aqueous dispersion as a sizing agent thus obtained is added to the pulp slurry together with a filler, a fixing agent, a paper strength enhancer, and the like. The amount of the aqueous dispersion added is usually
Approximately 0.05 to 2.0% by weight (solid content equivalent), preferably
The content is 0.1 to 1.0% by weight. If it is less than 0.05% by weight, it is difficult to achieve a sufficient size effect;
If it exceeds % by weight, there is no point in adding it in excess, which is not preferable. In addition, there are no particular restrictions on the filler that can be used, and any conventionally known filler can be used.Furthermore, calcium carbonate, which could not be used in conventional acidic papermaking methods, can be suitably used, so paper production costs are low. This has the advantage that it can greatly contribute to the reduction of As the fixing agent, various known fixing agents used as neutral sizing agents such as alkyl ketene dimer and alkenyl succinic anhydride can be used as they are. For example, cationized starch,
Epichlorohydrin modified product of polyamide polyamine resin, epichlorohydrin modified product of dicyandiamide resin, epichlorohydrin modified product of styrene-dimethylaminoethyl methacrylate copolymer, Mannitz modified product of polyacrylamide, acrylamide-dimethylaminoethyl methacrylate copolymer, Hoffmann polyacrylamide Examples include decomposition products, copolymers of dialkyl diallylammonium chloride and sulfur dioxide, and the like. The sizing agent used in the present invention can exhibit excellent sizing performance alone, but known neutral sizing agents,
For example, epichlorohydrin-modified products of styrene-dimethylaminoethyl methacrylate copolymer, alkenyl succinic anhydride, alkyl ketene dimer, epichlorohydrin-modified products of fatty acid-polyalkyl polyamine condensate, etc. can be used in combination. In the present invention, the pH during paper making is appropriately determined within the range of 6 to 9, and within this range, excellent size effects can be fully exhibited. Outside this range, the desired effect of the present invention will not be sufficient. Effects of the Invention According to the present invention, the following particularly remarkable effects are achieved. (1) Excellent size effect can be exhibited in the neutral range of PH6 or higher. (2) Since the sizing agent used in the present invention has excellent storage stability and can be used as is for paper making, it has superior workability compared to conventional techniques. (3) The sizing agent used in the present invention is cheaper than conventional neutral papermaking sizing agents, and calcium carbonate can be used, resulting in a significant reduction in papermaking costs. EXAMPLES The present invention will be described in more detail below with reference to production examples, working examples, and comparative examples, but the present invention is not limited to these examples. In each example, all parts and percentages are based on weight unless otherwise specified. Production Example 1 Into a 1L flask equipped with a stirrer, thermometer, nitrogen inlet tube, water separator, and cooler, 100 parts of gum rosin with an acid value of 170 and 8 parts of glycerin (equal ratio of charge (-
OH/−COOH) = 0.86) and place under nitrogen stream.
The mixture was heated to 250°C and esterified at the same temperature for 12 hours to obtain a reaction product with a softening point of 86°C and an acid value of 32. Production Example 2 A reaction product having a softening point of 79° C. and an acid value of 126 was obtained in the same manner as Production Example 1 except that the amount of glycerin charged was 2 parts (equivalent ratio = 0.22). Production Example 3 A reaction product having a softening point of 81°C and an acid value of 91 was obtained in the same manner as Production Example 1 except that the amount of glycerin charged was changed to 4 parts (equivalence ratio = 0.43). Production Example 4 A reaction product having a softening point of 83° C. and an acid value of 64 was obtained in the same manner as Production Example 1 except that the amount of glycerin charged in Production Example 1 was changed to 6 parts (equivalent ratio = 0.65). Production Example 5 A reaction product having a softening point of 88°C and an acid value of 8 was obtained in the same manner as Production Example 1 except that the amount of glycerin charged was changed to 12 parts (equivalent ratio = 1.29). Production Example 6 In Production Example 1, acid value 170 was used instead of gum rosin.
The same amount of tall oil rosin was used (equivalent ratio = 0.86).
Except for this, a reaction product having a softening point of 81° C. and an acid value of 34 was obtained in the same manner as in Production Example 1. Production Example 7 In Production Example 1, acid value 160 was used instead of gum rosin.
The procedure was the same as in Production Example 1, except that 106 parts of hydrogenated rosin (equivalent ratio = 0.86) was used, with a softening point of 85°C and an acid value.
30 reaction products were obtained. Production Example 8 In Production Example 1, acid value 168 was used instead of gum rosin.
The procedure was the same as in Production Example 1, except that the same amount of formaldehyde-modified rosin (modified with 2 parts of formaldehyde to 100 parts of gum rosin in Production Example 1) was used (equivalent ratio = 0.86), and the softening point was 81°C and the acid value was 29 reaction products were obtained. Production Example 9 Production Example 1 except that 10.4 parts of trimethylolethane was used instead of glycerin (equivalent ratio = 0.86) and the esterification reaction was carried out at 250°C for 30 hours.
In the same manner as in Production Example 1, a reaction product having a softening point of 83°C and an acid value of 30 was obtained. Production Example 10 In Production Example 1, 11.7 parts of trimethylolpropane was used instead of glycerin (equivalent ratio = 0.86),
Except that the esterification reaction was carried out at 250°C for 30 hours.
In the same manner as in Production Example 1, a reaction product having a softening point of 86°C and an acid value of 34 was obtained. Production Example 11 Production Example 1 except that 10.8 parts of diglycerin was used instead of glycerin (equivalent ratio = 0.86) and the esterification reaction was carried out at 250°C for 30 hours.
In the same manner as above, a reaction product having a softening point of 89°C and an acid value of 33 was obtained. Production Example 12 Except that 8.85 parts of pentaerythritol was used in place of glycerin in Production Example 1 (equivalent ratio = 0.86), and the esterification reaction was carried out at 250°C for 30 hours.
In the same manner as in Production Example 1, a reaction product having a softening point of 98°C and an acid value of 35 was obtained. Comparative Production Example 1 A reaction product having a softening point of 77° C. and an acid value of 150 was obtained in the same manner as Production Example 1, except that the amount of glycerin used in Production Example 1 was changed to 1 part (equivalent ratio = 0.11). Comparative Production Example 2 In Production Example 1, the amount of glycerin charged was changed to 20 parts (equivalent ratio = 2.2), and the esterification reaction was carried out at 250°C.
The same procedure as Production Example 1 was carried out except that the process was carried out for 30 hours.
A reaction product with a softening point of 91°C and an acid value of 3 was obtained. Comparative Production Example 3 Softening was carried out in the same manner as Production Example 1, except that 8.1 parts of ethylene glycol was used instead of glycerin in Production Example 1 (equivalent ratio = 0.86), and the esterification reaction was carried out at 200°C for 20 hours. A reaction product with a temperature of 65°C and an acid value of 40 was obtained. Comparative Production Example 4 In Production Example 1, 12.5 parts of neopentyl glycol was used instead of glycerin (equivalent ratio = 0.86),
Except that the esterification reaction was carried out at 200°C for 20 hours.
In the same manner as in Production Example 1, a reaction product having a softening point of 68°C and an acid value of 38 was obtained. Comparative Production Example 5 The same procedure as in Production Example 1 was carried out, except that 9.9 parts of propylene glycol was used instead of glycerin (equivalent ratio = 0.86) and the esterification reaction was carried out at 200°C for 20 hours. A reaction product with an acid value of 40 was obtained. Comparative Production Example 6 Except that 12.9 parts of triethanolamine was used instead of glycerin in Production Example 1 (equivalent ratio = 0.86), and the esterification reaction was carried out at 250°C for 30 hours.
In the same manner as in Production Example 1, a reaction product having a softening point of 70°C and an acid value of 37 was obtained. Comparative Production Example 7 In Production Example 1, tris(2-hydroxyethyl)isocyanurate was used instead of glycerin.
Using 22.6 parts (equivalent ratio = 0.86), the esterification reaction was carried out.
A reaction product having a softening point of 89°C and an acid value of 36 was obtained in the same manner as in Production Example 1, except that the reaction was carried out at 250°C for 30 hours. Examples 1 to 12 200 parts of each reaction product obtained in Production Examples 1 to 12 was dissolved in 200 parts of toluene, and 10 parts of an emulsifier (polyoxyethylene distyrylphenyl ether ammonium sulfate salt) and 800 parts of hot water (60°C) were dissolved. mixed with
After emulsifying using a high-pressure emulsifier, toluene was distilled off to prepare an aqueous dispersion with a concentration of 21%. Using each of the aqueous dispersions used as sizing agents obtained above, paper was made according to the neutral paper sizing method of the present invention, and the sizing performance was examined by the following method. <Method A> Pulp (L-BKP) was beaten into 450 ml of Canadian Standard Freeness to form a 1% slurry. Calcium carbonate (manufactured by Sankyo Seifun Co., Ltd., trade name "Escalon #100") was added to the slurry as a filler at 20% solid content based on the pulp, and cationized starch (manufactured by Oji National Co., Ltd., trade name "Escalon #100") was added to the slurry. After adding 1% of ``Cato 15''), 0.4% of the sizing agent obtained in each example was added to the pulp,
Filler retention agent (manufactured by Allied Colloid Limited,
0.02% of ``Percoll 47'' (trade name) was added and uniformly dispersed. The pH of the pulp slurry at this time is
It was 8.2. The obtained slurry was made into paper using a Tatsupi Standard Sheet Machine to have a basis weight of 70 g/m ² . The resulting wet paper was then compressed and dehydrated, dried at 100°C for 1 minute, and then adjusted to relative humidity.
Humidify at 65% for 24 hours, then measure each size degree (seconds) using the Stekicht method (JIS P8122)
was measured. <Method B> Pulp (L-BKP) was beaten into 450 ml of Canadian Standard Freeness to form a 1% slurry. A polyamide polyamine cationic polymer (manufactured by Arakawa Chemical Industry Co., Ltd., trade name "Arafix-100") was added to the slurry in an amount of 0.3% in terms of solid content based on the pulp, and the sizing agent obtained in each example was added to the pulp. 0.5% was added and uniformly dispersed. The pH of the pulp slurry at this time was 7.2. The obtained slurry was made into paper by the above method, and after drying and humidity control, the sizing degree (seconds) of each paper was measured by the Stekicht method. Comparative Examples 1 to 7 Using each reaction product obtained in Comparative Production Examples 1 to 7, an aqueous dispersion having a concentration of 21% was prepared in the same manner as in Example 1. Using the sizing agents of each comparative example obtained above, paper was made in the same manner as in the examples, and the sizing performance was examined. The test results are shown in Table 1.

【table】

【table】

[Table] Comparative Examples 8 to 10 Paper was made in the same manner as in Examples using a commercially available acidic paper sizing agent, and the sizing performance was examined. The results are shown in Table 2. In addition, as the above-mentioned commercially available acidic paper sizing agents,
The following three types were used. Reinforced rosin sizing agent (maleated rosin soap (solid content 30% by weight), trade name "Sizepine E" manufactured by Arakawa Chemical Co., Ltd.) Rosin emulsion sizing agent (composed of fumarated rosin, anionic emulsifier, and water) Solid concentration
50% by weight aqueous emulsion, trade name "Sizepine N-705" manufactured by Arakawa Chemical Industry Co., Ltd.) Synthetic sizing agent (alkenyl succinate (solid content concentration 40% by weight), trade name "Sizepine S-"
300” manufactured by Arakawa Chemical Industry Co., Ltd.)

[Table] As is clear from the above results, under neutral papermaking conditions, various commercially available acidic papermaking sizing agents did not exhibit any size effect.

Claims (1)

[Claims] 1. Rosin and at least one kind of trihydric alcohol and tetrahydric alcohol consisting of C, H, and O are mixed in such a manner that the ratio of hydroxyl group equivalent to carboxyl group equivalent is
A sizing agent in which the reaction product obtained by heating is dispersed in water at a charging ratio of 0.2 to 1.5 is added to the pulp slurry, without adding sulfuric acid.
A neutral paper sizing method characterized in that it is used in a neutral range of pH 6 to 9.