JP2007191831A - Bulking agent for papermaking use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a bulking agent excellent in bulking effect and capable of suppressing decline of paper strength, and to provide a method for producing bulk paper using the agent. <P>SOLUTION: The bulking agent is obtained by adding a polyalkylene oxide composed of 2-4C recurring units to at least one polybasic acid that is obtained by polymerizing a 16-20C higher unsaturated fatty acid. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bulking agent for papermaking. More specifically, the present invention relates to a bulking agent capable of improving the bulk of a sheet obtained by papermaking and obtaining a sheet having high strength.

  In recent years, efforts have been made to reduce the basis weight of paper products in order to minimize the use of pulp from the viewpoint of protecting the global environment, and the reuse of waste paper is regarded as important from the viewpoint of effective use of resources. . If the amount of pulp in the paper is simply reduced to reduce the weight of the paper, the paper becomes thinner and the opacity is reduced. Also, recycled paper made from waste paper has a problem that the bulkiness of the waste paper decreases because the pulp fibers of the waste paper are shorter than the virgin pulp fibers.

  In order to solve these problems, conventionally, various attempts have been made to improve the bulkiness. Patent Document 1 discloses a method using a cross-linked pulp, and Patent Document 2 discloses a method of mixing with synthetic fibers, but these methods make it difficult to recycle the pulp. Further, Patent Document 3 discloses a method of filling an inorganic substance between pulp fibers, but there is a disadvantage that the strength of paper is lowered, and none of them is effective.

  Further, as a bulking agent for paper, Patent Document 4 discloses a paper bulking agent containing an alkylene oxide adduct of a higher alcohol, and Patent Document 5 discloses a paper bulking agent containing a fat or sugar alcohol-based nonionic surfactant. The bulking agent is a paper bulking agent containing an AO adduct of fatty acid in Patent Document 6, and in Patent Document 7 is a paper bulking agent containing a cationic compound, an amine, an acid salt of an amine, and an amphoteric compound. Patent Document 8 discloses a polyhydric alcohol fatty acid ester. Furthermore, Patent Document 9 discloses a paper bulking agent containing a compound obtained by reacting an epihalohydrin with a compound obtained from an aliphatic carboxylic acid and a polyamine. However, with these compounds, the bulkiness is not at a satisfactory level, and a decrease in paper strength is inevitable.

Japanese Patent Laid-Open No. 4-185791 JP-A-3-269199 Japanese Patent Laid-Open No. 3-124895 International Publication No. 98/03730 Pamphlet JP-A-11-200263 JP-A-11-200284 JP-A-11-269799 JP 11-350380 A JP 2000-273792 A

  An object of the present invention is to provide a bulking agent that is excellent in bulkiness and can suppress a decrease in paper strength, and a method for producing bulky paper using the bulking agent.

  The present invention is bulky for papermaking, wherein polyalkylene oxide having 2 to 4 carbon atoms is added to at least one polybasic acid obtained by polymerizing a higher unsaturated fatty acid having 16 to 20 carbon atoms. It relates to the agent.

  It is preferable that the polyalkylene oxide has at least one of ethylene oxide and propylene oxide as a repeating unit.

  The present invention also relates to a bulky paper obtained by adding the paper bulking agent.

  Furthermore, the present invention also relates to a method for producing a bulky paper, in which the paper bulking agent is added during the papermaking process to make a paper.

  Since the bulking agent of the present invention has good bulkiness, it is possible to increase the thickness of the paper while minimizing the decrease in paper strength by adding the bulking agent in the papermaking process. Therefore, when manufacturing paper products, the amount of pulp raw material used can be reduced. Moreover, the strength of papermaking can be maintained at a high level.

  The present invention is bulky for papermaking, wherein polyalkylene oxide having 2 to 4 carbon atoms is added to at least one polybasic acid obtained by polymerizing a higher unsaturated fatty acid having 16 to 20 carbon atoms. It relates to the agent.

  Here, the polybasic acid means an acid containing two or more hydrogen atoms capable of neutralizing the base, that is, an acid having a basicity of 2 or more. Examples of the polybasic acid include dimer acid and trimer acid, and among these, dimer acid has a long-chain alkyl group and is preferable from the viewpoint of hydrophobizing pulp fibers.

  The higher unsaturated fatty acid preferably has 16 to 20 carbon atoms, and more preferably has 18 carbon atoms. When the number of carbon atoms is less than 16, the bulky effect tends to be insufficient. On the other hand, when the number of carbon atoms is larger than 20, it tends to be difficult to obtain raw materials industrially at low cost. Specific examples of the higher unsaturated fatty acid include oleic acid, linoleic acid, linolenic acid, and the like. For example, a polybasic acid can be obtained by reacting a monoenoic acid or dienoic acid of the higher unsaturated fatty acid with a Diels-Alder reaction. It is done. Practically, oleic acid and linoleic acid are the majority, and mixtures of polybasic acids based on dimer acid obtained with tall oil fatty acids containing a small proportion of saturated fatty acids are available on the market. For example, Haridimer (manufactured by Harima Kasei Co., Ltd.) is commercially available. The dimer acid can tolerate the presence of a small proportion of monomeric acid.

  Specific examples of the alkylene oxide (AO) having 2 to 4 carbon atoms include ethylene oxide (EO), propylene oxide (PO), butylene oxide, and the like. Of these, ethylene oxide and propylene oxide are preferred because of their good bulk effect and low price. When ethylene oxide and propylene oxide are used as the alkylene oxide, the molar ratio of EO / PO is preferably 1 / 0.3 to 1/10, particularly preferably 1/1 to 1/5. If the molar ratio of propylene oxide is less than 0.5 with respect to 1 mol of ethylene oxide, the bulkiness effect may be insufficient, and if it exceeds 10, the dispersibility in water may be poor. Further, the total number of added moles of alkylene oxide is preferably 3 to 100 mol, and particularly preferably 10 to 50 mol, per 1 mol of the polybasic acid. If the total number of added moles is less than 5 moles, the bulking effect is insufficient, and if it exceeds 100 moles, the product viscosity becomes high and handling may be difficult. In addition, a polyalkylene oxide does not ask | require a block and a random, and the order in the case of block addition does not ask | require.

In the present invention, the alkylene oxide addition method is not particularly limited, and is a usual method, that is, reacting an alkylene oxide with polybasic acid at 100 to 200 ° C. and 1 to 5 kg / cm ² for several hours using an alkali as a catalyst. Can be obtained.

  As pulp raw materials to which the bulking agent for papermaking of the present invention can be applied, hardwood bleached kraft pulp (hereinafter abbreviated as LBKP), softwood bleached kraft pulp (hereinafter abbreviated as NBKP), mechanical pulp, chemical pulp, waste paper pulp, Non-wood pulp such as bagasse and bamboo is also included.

  The bulking agent of the present invention can be added in any step in the papermaking process. For example, before and after beating, it is a preparation step for adding chemicals or the like before paper making, and even in the case of waste paper, it can be added in any step. In addition, a bulky paper can be produced by adding a bulking agent and simultaneously making paper.

  The bulking agent of the present invention becomes hydrophobic because the pulp is hydrophobized by being fixed to the pulp and dried in that state, so that hydrogen bonding between fibers hardly occurs. Since the hydrogen bond is reduced, the strength is naturally weaker than that of the paper with no bulking agent added. However, the bulking agent of the present invention causes little decrease in strength.

  The bulk paper made using the bulking agent of the present invention preferably has a density reduction rate of 3% or more and a strength of 90% or more as compared with the bulk-free additive-added paper.

  Although there is no restriction | limiting in particular in the addition amount of the bulking agent for paper manufacture of this invention, It is preferable that it is 0.01-5 weight% with respect to a pulp, and it is more preferable that it is 0.1-2 weight%. If the bulking agent is less than 0.01% by weight, sufficient bulky performance cannot be obtained, and even if it exceeds 5% by weight, bulky performance corresponding to the amount added cannot be obtained.

  In the present invention, other chemicals generally used in the papermaking process can be added. Examples include sizing agents, wet paper strength enhancers, dry paper strength enhancers, pitch control agents, slime control agents, yield improvers, antifoaming agents, fillers, pigments, and dyes. These other chemicals can be added in the stock preparation process. Specifically, the sizing agent includes alkyl ketene dimer (hereinafter abbreviated as AKD), and the dry paper strength enhancer includes cationized starch.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

<Manufacture of bulking agent>
1. Production of dimer acid- (10EO / 20PO) (random copolymer)
Dimer acid obtained by polymerization of oleic acid and linoleic acid; 583 g of Halidimer 200 (76% dimer acid, 7% monomer acid, 17% trimer acid (manufactured by Harima Kasei Co., Ltd.)) was placed in a 5-liter autoclave, and caustic potash 2.2g was added and it heated up to 130 degreeC. Thereafter, 1600 g of a mixture of ethylene oxide / propylene oxide = 1/2 (molar ratio) was reacted at 125 to 135 ° C. and a pressure of 1 to 3.5 kg / cm ² , then cooled and neutralized with acetic acid to increase the bulk of the random copolymer. An agent was obtained.

  In addition, as for the bulking agent of the random copolymer used in the other examples, ethylene oxide and propylene oxide were mixed so that the molar ratios shown in Table 1 and Table 2 were obtained, and further, the random copolymer used in the comparative example The bulking agent was produced in the same manner as described above except that lauric acid was used instead of dimer acid.

2. Production of dimer acid-5EO-30PO (block copolymer)
583 g of Halidimer 200 was added to a 5 liter autoclave, 2.5 g of caustic potash was added, and the temperature was raised to 130 ° C. Then ethylene oxide 125-135 ° C. The 220g is reacted at a pressure 1~3.5kg / cm ^2, followed by 125-135 ° C. The 1740g of propylene oxide is reacted at a pressure 1~3.5kg / cm ^2, then cooled The block copolymer bulking agent was obtained by neutralizing with acetic acid.

  In addition, the block copolymer bulking agent used in the other examples was obtained by sequentially reacting ethylene oxide and propylene oxide so that the molar ratios shown in Table 1 and Table 2 were obtained. The bulking agent was produced by the same method as described above except that stearic acid was used instead of dimer acid.

  Table 1 shows the composition of the bulking agent produced. In addition, the order of ethylene oxide (EO) and propylene oxide (PO) of the block copolymer in Table 1 is the order of description, and the numbers before ethylene oxide and propylene oxide indicate the degree of polymerization.

Examples 1-11
LBKP was beaten to 450 ml freeness to prepare a pulp slurry. While stirring this pulp slurry with a stirrer, 0.2 wt% of the AKD sizing agent was added to the pulp and stirred for 5 minutes. Thereafter, 0.5% by weight of cationized starch was added to the pulp and stirred for 5 minutes. Finally, the bulking agent shown in Table 1 was added to the pulp by 0.5% by weight and stirred for 5 minutes. Next, the paper was made to a basis weight of 60 g / m ² with a TAPPI standard sheet machine (manufactured by Kumagai Riki Kogyo Co., Ltd.), pressed at 0.34 MPa for 5 minutes, and then dried at 105 ° C. for 5 minutes with a drum dryer. After drying, the sheet was conditioned at 20 ° C. and a humidity of 65% for 1 day to produce a sheet, and the density and tear length of the sheet were measured by the following methods. The results of density and tear length are shown in Table 1.

<Density>
The basis weight (g / m ² ) was calculated by measuring the weight of the conditioned sheet, the thickness (μm) was measured with a thickness gauge, and the density (g / cm ³ ) was obtained from the following formula. . In addition, bulkiness is so favorable that a density is small.
Density (g / cm ³ ) = basis weight (g / m ² ) / thickness (μm)

<Cut length>
The maximum load (kgf) was measured with a tensile tester, and the fracture length (km) was determined from the following formula.
Breaking length (km)
= Maximum load (kgf) × 1000 / (basis weight (g / m ² ) × test specimen width (mm))

Comparative Examples 1-3
A block copolymer of propylene oxide and ethylene oxide was added to stearic acid, which is a monomer acid as a bulking agent (Comparative Example 1), and a random copolymer of propylene oxide and ethylene oxide was added to stearic acid, which was a monomer acid, as a bulking agent (comparison) A sheet was produced under the same conditions as in Example 1 except that Example 2) and no bulking agent were added (Comparative Example 3). Table 1 shows the results of the density and tear length of the obtained sheet.

Examples 12-22
A pulp slurry prepared by blending freeness 450 ml of NBKP and freeness 180 ml of high-quality old recycled paper at a weight ratio of 70/30 wt% was added with 0.1 wt% of AKD sizing agent to the pulp while stirring with a stirrer. Stir for 5 minutes. Thereafter, 0.5% by weight of cationized starch was added to the pulp and stirred for 5 minutes. Finally, the bulking agent shown in Table 2 was added to the pulp by 0.5% by weight and stirred for 5 minutes. . Next, paper was made to a basis weight of 60 g / m ² with a TAPPI standard sheet machine, pressed at 0.34 MPa for 5 minutes, and then dried at 105 ° C. for 5 minutes with a drum dryer. After drying, the sheet was conditioned at 20 ° C. and 65% for 1 day, and then the density and tear length were measured in the same manner as in Example 1.

Comparative Examples 4-6
A block copolymer of propylene oxide and ethylene oxide was added to stearic acid, a monomeric acid as a bulking agent (Comparative Example 4), and a random copolymer of propylene oxide and ethylene oxide was added to stearic acid, a monomeric acid, as a bulking agent (comparison) A sheet was produced under the same conditions as in Example 12 except that Example 5) and no bulking agent were added (Comparative Example 6). Table 2 shows the results of the density and tear length of the obtained sheet.

  It can be seen that the paper using the bulking agent of Examples 1 to 22 has improved bulkiness without reducing the strength of the paper as compared with the paper without the bulking agent added. Furthermore, it turns out that bulkiness is favorable rather than the case where the alkylene oxide adduct of a monomeric acid is used.

Claims (4)

A bulking agent for papermaking, wherein a polyalkylene oxide having 2 to 4 carbon atoms is added to at least one polybasic acid obtained by polymerizing a higher unsaturated fatty acid having 16 to 20 carbon atoms. The paper bulking agent according to claim 1, wherein the polyalkylene oxide has at least one of ethylene oxide and propylene oxide as a repeating unit. Bulky paper obtained by adding the paper bulking agent according to claim 1 or 2. A method for producing a bulky paper, wherein the bulking agent for papermaking according to claim 1 or 2 is added during a papermaking process to make a paper.