Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
  • D21H17/24—Polysaccharides
  • D21H17/25—Cellulose
  • D21H17/26—Ethers thereof
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/63—Inorganic compounds
  • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
  • D21H17/675—Oxides, hydroxides or carbonates

Definitions

• the present invention relates to a method for producing paper. More specifically, the present invention relates to a method for producing paper containing cellulose fiber, aluminum sulfate, and titanium dioxide, wherein titanium dioxide particles can be contained in paper at a high yield during papermaking. is there. Background art
• JP-A-5-78997 a method using an amphoteric water-soluble polymer and anionic colloidal silica and / or bentonite (JP-A-9-195197)
• JP-A-9-195197 a method using an amphoteric water-soluble polymer and anionic colloidal silica and / or bentonite
• An object of the present invention is to provide a method for producing paper containing cellulose fibers, aluminum sulfate and titanium dioxide, which improves the yield of containing titanium dioxide with respect to the paper and has excellent optical properties and strength properties. It is in.
• the stock when a paper stock containing cellulose fibers, aluminum sulfate and titanium dioxide is subjected to a papermaking process to make paper, the stock is converted into an aqueous slurry containing the cellulose fibers by carbohydrate.
• the degree of substitution with the xymethyl group is adjusted to 0.3 to 0.6. It is characterized by being prepared by adding and mixing oxymethylcellulose, and then further adding and mixing aluminum sulfate and titanium dioxide.
• the amount of said force Rubo Kishimechiruseru port over scan contained in the paper stock in the papermaking process of the present invention 0 the absolute dry weight of the cell opening over cellulose fiber. 0. 5 to 3.0 mass 0/0 It is preferable to control.
• the amount of the aluminum sulfate contained in the stock is 0.1 to 100% of the absolute dry mass of the cellulose fibers.
• the amount of the titanium dioxide contained in the stock is 1 to 25 mass of the absolute dry weight of the cellulose fiber.
• the inventors of the present invention can remarkably improve the yield of titanium dioxide content at the time of papermaking inexpensively, easily, and significantly improve the quality of the obtained paper (such as optical properties and mechanical strength properties). We have been conducting intensive research on ways to improve).
• the fine particles of titanium dioxide generally have a negative charge, and therefore are considered to be adsorbed on the cellulose fiber sheet (paper) by a static action via a cationic agent.
• the present inventors have preliminarily added and mixed carboxymethylcellulose whose degree of substitution with carboxymethyl groups has been adjusted to 0.3 to 0.6 in a cellulose fiber-containing aqueous slurry before papermaking.
• the raw material cellulose fiber used in the method of the present invention is not particularly limited, and generally used known papermaking pulp can be used.
• chemical pulp such as sulfite pulp, craft pulp, and soda pulp, and semi-chemical pulp Pulp
• wood pulp such as pulp, pulp, non-wood pulp such as kozo, honey, hemp, etc .
• deinked pulp manufactured by processing waste paper and unbleached pulp and bleached pulp. Pulp.
• the titanium dioxide used in the method of the present invention has an average primary particle diameter in the range of 0.1;! To 0.4 ⁇ , and the crystal form is selected from rutile type and anatase type, and these are used alone. Or may be used in combination.
• Titanium dioxide is preliminarily dispersed in water and then provided for preparation of a stock.
• a dispersant may be added to prevent reaggregation of particles.
• the dispersant one or more of sodium hexamethacrylate, sodium pyrophosphate, sodium polyarylate and the like can be used.
• the amount of titanium dioxide added to the paper stock can be appropriately set according to the quality of the target paper, the intended use, and the like. Generally, it is preferably from 1 to 25% by mass, more preferably from 3 to 20% by mass, based on the absolute dry mass of the cellulose fiber in the stock.
• the carboxymethylcellulose (hereinafter referred to as CMC) used in the method of the present invention is a cellulose derivative derived from wood pulp or linter pulp as a raw material and reacted with monochloroacetic acid or the like.
• CMC carboxymethylcellulose
• carboxyethylcellulose which is a cellulose derivative similar to CMC, the effect is lower than that of CMC and the cost is high. Need not be used as an essential ingredient.
• the degree of carboxymethyl group substitution (degree of etherification) of the CMC used in the method of the present invention is adjusted to the range of 0.3 to 0.6. Those having a degree of substitution of less than 0.3 are insoluble in water, are not adsorbed on the surface of cellulose fibers, are simply mixed with cellulose fibers, and have a high yield of titanium dioxide on paper. Can't improve. On the other hand, those with a degree of substitution exceeding 0.6 have an excessive number of ionic groups (one CH 2 COO— group) in the molecule, and therefore have a negative charge on the cellulose fiber with a negative charge.
• CCM adsorbs on the surface of the cell mouth fiber even if the electrolyte is co-existed and the electrostatic repulsion is shielded to some extent due to the strong repulsion and poor affinity with the cellulose fiber. And the yield of titanium dioxide on paper cannot be improved.
• the degree of carboxymethyl group substitution of CMC can be measured by the method described below.
• the CMC used in the method of the present invention depends on the properties of the cellulose fibers used. As described above, various polymerization degrees can be produced by the CMC production method, but the viscosity of a 1% aqueous solution is 5 to 16,000 mPa-s (0.1 l). N-NaCl solvent, 25 ° C, B-type viscometer), average polymerization degree of 100 to 4,500, average molecular weight of 20,000 to 100,000 Is preferred.
• the CMC used in the method of the present invention generally has a carboxylic acid group formed into a sodium salt or a sodium salt of a carboxylic acid.
• the bean or ray should be a canoleboxymethinoresenorelose-powered bead, but for simplicity, the description of sodium or calcium is omitted, and this is simply referred to as carboxymethylcellulose (CMC).
• CMC carboxymethylcellulose
• the CMC used in the method of the present invention includes its sodium salt, potassium salt or ammonium salt, but it is inexpensive, easily available, and highly effective. It is preferable to use a sodium salt.
• an aqueous solution of CMC is used. If the CMC concentration of this aqueous solution is too high, the viscosity of the CMC aqueous solution is high, and diffusion into the cellulose fiber slurry becomes poor. becomes therefore, it is preferable that CMC concentration is 0.0 1 to 5.0 wt%, more preferably in the range of 0.1 to 3.0 mass 0/0.
• the solvent for dissolving CMC is generally water, and in the method of the present invention, an aqueous solution of CMC is usually used. However, as long as the CMC is stably dissolved, the solvent may be compatible with water if necessary. Certain solvents such as methanol and ethanol may be mixed with water at a ratio of 10.0 to 30.0%, and if necessary, as long as CMC is stably dissolved. First, an additive such as an electrolyte such as sodium sulfate may be mixed.
• the amount of CMC added in the method of the present invention should be appropriately set according to the degree of substitution of CMC, the type and use of the paper to be produced, the required performance, etc. However, it is preferably used in an amount of 0.05 to 3.0% by mass, more preferably 0.1 to 1.0% by mass, based on the dry mass of the cellulose fiber. The effect becomes more remarkable as the amount of CMC used increases, but it is 0.05 to 3.0 mass. A sufficient effect can be obtained with the addition amount of / 0 , and if it exceeds 3.0% by mass, the formation of the obtained paper may be poor or the drainage may be insufficient. In addition, the cost of CMC limits its use due to paper applications and economics. If the amount of CMC is less than 0.05% by mass, the effect of improving the yield containing titanium dioxide may be insufficient.
• the cellulose fiber concentration of the cell mouth fiber slurry is preferably 1.0 to 5.0% by mass in terms of solid content. More preferably, it is 2.0 to 4.0 mass%. If the concentration is too high, stirring may be difficult and mixing may be insufficient.On the other hand, if the concentration is too low, the interaction between cellulose fibers and CMC will be insufficient, and the adsorption of CMC to the surface of cellulose fibers will be insufficient. May be uneven.
• CMC in preparing the stock, first, CMC is added to an aqueous slurry of cellulose fibers, and then aluminum sulfate and titanium dioxide are added.
• the order of addition of aluminum sulfate and titanium dioxide may be appropriately determined according to the state of addition during papermaking. After the addition of aluminum sulfate and titanium dioxide, the amount of negative charge on the pulp fiber surface does not increase, and the effect of improving the yield of titanium dioxide cannot be obtained.
• the amount of titanium dioxide and the amount of aluminum sulfate used as a fixing agent for various papermaking chemicals can be appropriately set according to the type, use, and required quality of the paper. 0.1 to 3.0% by mass based on the dry mass of the fiber , Yo Ri preferably 1.0 to 2.0 mass 0/0. If it is less than 0.1% by mass, the fixing ability of titanium dioxide may be insufficient, and if it exceeds 3.0% by mass, not only is it economically disadvantageous but also
• the formation of the paper may be poor and the storage stability may be deteriorated.
• known papermaking agents such as a papermaking paper strength enhancer and a wet paper strength enhancer, a sizing agent, a filler, a retention aid, a dye, an antifoaming agent, a preservative, and a viscosity reducing agent are used. They can be added to the stock as needed, and their type and amount are not particularly limited as long as the quality required for the obtained paper can be satisfied. In order to exert the respective effects of the above papermaking chemicals, it is preferable to add them after the addition of CMC.
• Papermaking by the method of the present invention can be carried out by using a known wet paper machine, for example, a commercial-scale paper machine such as a fourdrinier-type paper machine, a gap former-type paper machine, a circular net-type paper machine, or a short-mesh type paper machine. And the above-mentioned stock is supplied to this.
• a commercial-scale paper machine such as a fourdrinier-type paper machine, a gap former-type paper machine, a circular net-type paper machine, or a short-mesh type paper machine.
• the yield of titanium dioxide on paper obtained by the conventional method can be improved by about 10 points by the method of the present invention.
• the base paper obtained in this way can be sized using starch, PVA, PAM, etc. with various size presses, roll coaters, etc., of course.
• a method of performing a size press treatment by increasing the solid concentration of the paste by using a film-metering type size press device is preferably used.
• various electrolytes as a conductive agent to the surface treatment agent starch, ⁇ ⁇ , PAM, and the like.
• the electrolyte include sodium sulfate, sodium chloride, and the like.
• Paper produced by the method of the present invention is used as it is as a product It can also be used as a base paper for paper having a coating composition layer, such as printing paper and information recording paper.
• a coating composition layer such as printing paper and information recording paper.
• % means “% by mass” in all cases, and the amount of the additive added to the cellulose fiber slurry is based on the mass of the absolutely dry paper stock. "% By mass”.
• the measurement was carried out in accordance with JIS SP 8113 and indicated by the breaking length (km).
• the measurement was performed in accordance with JIS P8138.
• the stock density and ash content were measured according to TAPPIT 26 9-cm 92.
• the total stock density in the headbox is HT
• the total stock density in the tray is WT
• the 100% fraction of ash in the headbox is F1
• the percentage of ash in white water is F2.
• Fiber, fine fiber, filler was calculated according to the following equations.
• Total stock OPR (%) ⁇ (HT-WT) / HT ⁇ x 1 0 0
• a 1% solution was prepared using 0.1 N—NaCl as a solvent, and measured at 25 ° C with a B-type viscometer.
• the degree of substitution of the test carboxymethylcellulose (CMC) was calculated according to the following equation.
• A represents the amount of 1/10 normal sulfuric acid (ml) consumed by the alcohol in 1 g of the sample
• a represents the amount of 1/10 normal sulfuric acid added
• f 1 represents the factor of 1/10 normal sulfuric acid
• b represents the titer (ml) of 1Z10 normal hydroxide power
• f2 represents the factor of 1/10 normal potassium hydroxide.
• M represents the mass (g) of bone dry CMC.
• Example 1 Softwood bleached pulp and hardwood bleached pulp were mixed in a ratio of 3: 7 using an experimental Niagara Vita and beaten to 400 mL of Canadian Standard Freeness (CSF).
• Aqueous scan la rie of the pulp fibers (pulp concentration 2.0 mass 0/0)., Degree of substitution 0.4 6 CMC (solids concentration 1. Solution viscosity 2 0 0 TadashiTadashi% m P a ⁇
• a paper strength agent containing anionic polyacrylamide as a main component (trade name: Polyaclon ST13, manufactured by Misa Ceramics) 0.5% by mass, papermaking Rosin sizing agent for use (trade name: SPE, Arakawa Chemical Industries, Ltd.) 0.3% by mass, cation-modified starch (trade name: Kate 15, National Starch Co., Ltd.) 1.0% by mass, aluminum sulfate Niumu 1.5 mass 0/0, titanium dioxide (particle diameter 0. 2 / m, anatase, trade name: B 1 0 1, Nippon talc Co., Ltd.) 1 7 wt%, was added in the order of the paper A preparation was prepared.
• paper having a basis weight of 90 g / m 2 was prepared using a square sheet machine for laboratory use, and air-dried indoors.
• the hand-made sheet was conditioned for 24 hours at 23 ° C. and 50% RH, and then subjected to a quality evaluation test. Table 1 shows the results.
• Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality. However, the amount of CMC added was set to 0.05% by mass based on the absolute pulp mass. Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality.
• the CMC is a CMC with a solution viscosity of 900 mPa * s at a solid concentration of 1% and a degree of substitution of 0.4 (trade name: Cellogen # 412C, manufactured by Daiichi Kogyo Seiyaku ) Was used. Table 1 shows the test results.
• a handsheet was prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality.
• the CMC a CMC with a solution viscosity of lOOmPas with a solid content of 1% and a substitution degree of 0.35 was used, and the amount of CMC added to the absolute dry mass of the pulp fiber was 3. 0 mass. /.
• the amount of aluminum sulfate added was 1.0% by mass. Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality. However, the amount of aluminum sulfate added to the absolutely dry mass of pulp fiber was 0.1% by mass.
• the test results are shown in Table 1 Comparative Example 1 Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality. However, no CMC was added to the stock. Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality.
• the addition of CMC was made after the addition of titanium dioxide. Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality.
• the CMC used was CMC with a degree of substitution of 0.6 (solution viscosity of 500 mPa ⁇ s with a solid concentration of 1%, trade name Serogen HH, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). The addition rate was 3.3%. Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 9, and the obtained paper was tested to evaluate the quality. However, the amount of CMC added was 0.02%. Table 1 shows the test results.
• a handsheet was prepared in the same manner as in Comparative Example 1, and the obtained paper was tested to evaluate the quality.
• a retention improver containing a cationic polyacrylamide as a component (trade name: Himolock DR1200H, manufactured by Himo) is based on the absolutely dry pulp fiber content. . 0 4 quality % was added after the addition of titanium dioxide.
• the test results are shown in Table 1 Comparative Example 5
• Hand-made sheets were prepared in the same manner as in Comparative Example 1, and the obtained paper was tested to evaluate the quality.
• the yield improver containing a cationic polyacrylamide as a component (trade name: Percoll 57, manufactured by Kyowa Sangyo Co., Ltd.) is 0.04% by mass based on the absolute dry mass of the pulp fiber.
• 0.1% by mass of modified bentonite (trade name: Hydrocol 0, manufactured by Kyowa Sangyo Co., Ltd.) were added after addition of titanium dioxide. Table 1 shows the test results.
• Hand-made sheets were prepared in the same manner as in Example 1, and the obtained paper was tested to evaluate the quality. However, the amount of aluminum sulfate added was 3.5% by mass with respect to the dry mass of the pulp fibers. Table 1 shows the test results.
• the use of the method of the present invention makes it possible to easily produce titanium dioxide with high yield and excellent paper quality.
• the yield of titanium dioxide was improved (Example 1 Comparative Example 1).
• the effect is high compared to the case where the retention improvement system is used (Example 1, Comparative Examples 4 and 5).
• the lower the degree of substitution of CMC the higher the effect, and when CMC with a degree of substitution of more than 0.6 is used, the effect is remarkably reduced (Examples 1, 5 and Comparative Example 3).
• the method of the present invention is a method for producing paper that improves the yield of titanium dioxide, provides paper of excellent paper quality, and cleans the papermaking system to improve operability. It has.

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• 2003
  • 2003-03-13 CN CNB038260735A patent/CN100373003C/zh not_active Expired - Fee Related
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