JP2729792B2 - Paper manufacturing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing paper, and more particularly to a method for producing paper that improves drainage. 2. Description of the Related Art Additives used in the papermaking process include sizing agents,
Paper strength improvers for improving paper strength, retention improvers for improving the yield of fillers and fine fibers, and drainage improvers for improving drainage on papermaking wires are used. For example, a so-called amphoteric (meth) acrylamide copolymer in which an anionic group and a cationic group are introduced is used as an additive. Among them, the cationic group ratio (the cationic group contained in all the monomer units constituting the polymer) is used. Of 20% or less, a paper strength improver and a cationic group ratio of 20 to 50%, a paper strength improver and a drainage improver, and a cationic group ratio of 50% or more. Each is used as a drainage improver. JP-A-62-191598 discloses a method in which bentonite is used in combination with a cationic polymer to improve properties such as drainage, retention, drying properties and formation. Problems to be Solved by the Invention However, when an amphoteric (meth) acrylamide polymer having a low cationic group ratio is used as a paper strength improver, drainage is poor and there is a problem in terms of production efficiency. Further, when an amphoteric (meth) acrylamide polymer having a high ratio of cationic groups is used as a drainage improver, the effect of improving drainage is not yet sufficient. If the addition rate of the amphoteric (meth) acrylamide polymer is increased in order to improve the drainage, the drainage is improved, but the texture may be disturbed and the strength of the paper may be reduced. Also, the method described in JP-A-62-191598 is different from the amphoteric polymer of the present invention in that a cationic polymer having a molecular weight of 500,000 or more (preferably 1,000,000 or more), which is usually used as a retention aid, is combined with bentonite. The effects (water drainage, paper strength, etc.) are not yet sufficiently satisfactory. Accordingly, an object of the present invention is to provide a method for producing paper that can improve drainage without reducing the strength of the paper. Means for Solving the Problems The present invention provides a method for solving the above problems, which has an average molecular weight
In a method for producing paper using a 100,000 to 1,000,000 polymer and amphoteric amphoteric compound and an additive containing bentonite, in a method for producing paper, the polymer is acrylamide and / or
Or a polymer containing methacrylamide and an anionic monomer in a polymerization component, wherein the amphoteric compound is a Hoffman reaction product or a Mannich reaction product of the polymer, or the amphoteric compound is acrylamide and / or
Another object of the present invention is to provide a method for producing paper, which is a polymer containing a methacrylamide, an anionic vinyl monomer, and a cationic vinyl monomer in a polymerization component. Hereinafter, the present invention will be described in detail. The amphoteric compound used in the present invention has a structure having an anionic group and a cationic group in a polymer containing acrylamide and / or methacrylamide as a polymerization component, and is a homopolymer of acrylamide and / or methacrylamide or Either one or both of an anionic group and a cationic group can be introduced by modifying a polymer with another monomer, and an anionic monomer or a cationic monomer and acrylamide and / or methacrylamide can be used as a polymerization component. Introduce one of an anionic group or a cationic group during polymerization by modifying the polymer contained in,
The other of the anionic group and the cationic group may be introduced later, and further, a polymer containing an anionic monomer, a cationic monomer, and acrylamide and / or methacrylamide in a polymerization component is formed, and then modified. Alternatively, both an anionic group and a cationic group may be introduced during polymerization. The polymer containing acrylamide and / or methacrylamide in the polymerization component used in combination with the bentonite needs to be an amphoteric compound. When the polymer is a mere cationic compound, both the drainage and paper strength are not sufficient. I can not say. In order to introduce a cationic group by modifying a polymer containing acrylamide and / or methacrylamide in the polymerization component, a Hoffmann decomposition reaction, a Mannich reaction, and the like for a polymerization unit based on a monomer having an amide group such as acrylamide and / or methacrylamide are further performed. For example, a transamidation reaction with a polyamine can be used. In this case, when using an anionic vinyl monomer as a polymerization component of the polymer before modification, a monocarboxylic acid such as acrylic acid and methacrylic acid, or a dicarboxylic acid such as itaconic acid, fumaric acid, and maleic acid, and sodium , Potassium, ammonium salts and the like. These are 0.5 to 3 in the polymerization component.
It is preferably contained in an amount of 0 mol%, particularly preferably 1 to 2 mol%.
0 mol%. When the anionic polymer is modified as described above, the introduction ratio (cation modification ratio) of the cationic group is preferably 1 mol% or more of the polymer structural unit based on acrylamide and / or methacrylamide, and is preferably less than 1 mol%. The effect of improving drainage is remarkable as compared with. In order to introduce a cationic group by using a cationic vinyl monomer as a polymerization component, a compound represented by the following general formula (I): (Where A is oxygen or NH, n is an integer of 2 to 4, R ₁
Represents H or a methyl group, and R ₂ and R ₃ represent the same or different lower alkyl groups. Also, a compound of the following general formula [II]: (Where A is oxygen or NH, n is an integer of 2 to ₄ , R ₄
Represents an H or methyl group, R ₅ , R ₆ and R ₇ represent the same or different lower alkyl groups, and X ⁻ represents an anion group. Also, a compound of the following general formula [III]: (Where A is oxygen or NH, n is an integer of 2 to 4, R ₈
Represents an H or methyl group, R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ represent the same or different lower alkyl groups, and X ⁻ and Y ⁻ represent the same or different anion groups. Also, a compound of the following general formula [IV]: (Where A is oxygen or NH, n is an integer of 2 to 4, R
₁₄ is H or a methyl group, R ₁₅ and R ₁₆ are the same or different lower alkyl groups and X ^- anion groups, respectively. ) Are exemplified. Examples of the anionic monomer used together with such a cationic monomer include the above-described monocarboxylic acids,
A single or a plurality of monomers belonging to the dicarboxylic acid are exemplified. As described above, other polymers can be used for the polymer having a cationic monomer, an anionic monomer, and acrylamide and / or methacrylamide as a polymerization component. Is preferably 0.5 to 80 mol%, particularly preferably 1 to 50 mol%, and the anionic vinyl monomer is preferably 0.5 to 30 mol%, particularly preferably 1 to 20 mol%. As described above, an amphoteric compound in which one or both of an anionic group and a cationic group are introduced after the formation of the polymer, or an amphoteric compound in which both groups are introduced during polymerization can be obtained, but a polymer of these amphoteric compounds, that is, a cation When a group or an anionic group is introduced during polymerization, the polymer after the polymerization, and when these groups are introduced by modification to the polymer, the average molecular weight of the polymer before the modification is obtained from the viscosity-molecular weight curve of polyacrylamide. The calculated average molecular weight is 100,000-100
It is preferably 10,000, and particularly preferably 300,000 to 800,000. If the molecular weight is too low, the effect of improving drainage and the effect of improving the yield of fine fibers and filler are not as good as those in the preferred molecular weight range, and if the molecular weight is too high, these effects are good, but the paper is better than that in the preferred molecular weight range. The texture is not good and the strength of the paper is not good. If the content of acrylamide and / or methacrylamide is too low, the strength of the paper may be lower than that in the preferable range. Bentonite used in the present invention preferably has an average particle diameter of 50 μm or less, and particularly preferably a powder of 30 μm or less. Bentonite is a clay containing montmorillonite as a main component, and there are sodium bentonite, calcium bentonite, activated bentonite with sodium carbonate, potassium carbonate, and the like, and any of them can be used. Particularly, sodium bentonite and activated bentonite are used. preferable. When the bentonite is added, the powder may be directly added to the pulp slurry, but it is preferable to prepare a bentonite slurry having a concentration of 0.5 to 10% with water in advance and to add it. In the method for producing paper of the present invention, the amphoteric compound is used by being added to the pulp slurry.
The amount is preferably 0.01 to 3 parts by weight, particularly preferably 0.02 to 2 parts by weight, per 100 parts by weight. On the other hand, bentonite is preferably 0.01 to 5 parts by weight, particularly preferably 0.02 to 3 parts by weight, per 100 parts by weight of the pulp. When the amount is in the range of 0.01 to 5 parts by weight, the effect of improving drainage is preferable as compared with the case where the amount is less than this, and the decrease in paper strength is suppressed as compared with the case where the amount is more than this. When the amphoteric compound and bentonite used in the present invention are added to the pulp slurry, it is desirable to add and mix both separately, and in the method of mixing both in advance and adding the mixed solution to the pulp slurry, the former method is used. A remarkable drainage improvement effect cannot be obtained. Example Next, an example will be described in detail. In the following, percentages or parts are by weight unless otherwise specified. For convenience, monomers are abbreviated as follows. Ai (i = 1,2,3,4) A ₁ : dimethylaminopropyl acrylamide A ₂ : dimethylaminopropyl methacrylamide A ₃ : dimethylaminoethyl acrylate A ₄ : dimethylaminoethyl methacrylate Bi (i = 1, 2, 3 , 4): i represents the same number of quaternary ammonium salt monomers of Ai. That is, compound example B ₁ in which R ₅ , R ₆ , and R ₇ in the general formula [II] are methyl groups: trimethyl-3-[(1-oxo-2-propenyl) aminopropyl] ammonium chloride Ci (i = 1,2,3,4): i is a bisquaternary ammonium salt monomer of the above general formula [III] corresponding to the same number of Ai, and R ₉ , R ₁₀ , R ₁₁ , R ₁₂ Is a methyl group. C ₁ : 2-Hydroxy-N, N, N, N ′, N′-pentamethyl-N′-3-[(1-oxo-2-propenyl) amino] propyl-1,3 -Propanediaminium dichloride Di (i = 1,2,3,4): i represents a quaternary ammonium salt monomer of the general formula [IV] corresponding to the same number of Ai, and R ₁₅ ,
A compound wherein R ₁₆ is a methyl group. Example D _1: Benzyl Dimethyl-3- [1-oxo-2-propenyl) amino propyl] ammonium chloride AAM: acrylamide MAM: methacrylamide AA: acrylic acid MAA: methacrylic acid MA: maleic acid FA: fumaric acid DMA: dimethylamine DEA: diethylamine DET: diethanolamine BHA: benzylhydroxyethyldimethylammonium chloride HEA: hydroxyethyltrimethylammonium chloride APA: 3-Aminopropyldimethylamine AER: Amine-epichlorohydrin resin (see Japanese Patent Application Laid-Open No. 58-29823) In carrying out the methods for producing the papers of this example and comparative examples, amphoteric compounds were prepared as follows. (Example using the Hoffman reaction) Anionic acrylamide polymer having an average molecular weight of 300,000 and containing 2 mol% of acrylic acid and 98 mol% of acrylamide is modified with benzylhydroxyethyldimethylammonium chloride (BHA) as a modifier. Was added to an aqueous solution containing sodium hypochlorite and KOH, and a Hoffman reaction was carried out according to a conventional method. Thereafter, the pH was adjusted to 4.5 with dilute hydrochloric acid to obtain amphoteric compound 1-A. Amphoteric compounds 1-B shown in Table 1 in the same manner as above
1-J and compounds 1-a to 1-e for comparative examples were obtained. In the table, the molecular weight is an average molecular weight determined from a polyacrylamide viscosity-molecular weight curve. The same applies hereinafter. (Example using Mannich reaction) Formaldehyde and dimethylamine are added to an anionic acrylamide polymer having an average molecular weight of 600,000 composed of 10 mol% of methacrylic acid and 90 mol% of acrylamide, and a Mannich reaction is carried out in accordance with a conventional method to carry out an amphoteric compound. 2-
A was obtained. In the same manner as described above, the amphoteric compounds 2-B to
2-J and the compounds for comparative examples 2-a to 2-e were obtained. (Example of obtaining amphoteric compound only by polymerization) A mixture consisting of 95 mol% of acrylamide, 2 mol% of dimethylaminopropylacrylamide and 3 mol% of itaconic acid was polymerized by a usual aqueous polymerization method to obtain a liquid of amphoteric compound 3-A. . The solid content of this amphoteric compound is 10.1%,
The molecular weight was 500,000. Amphoteric compounds 3-B to 3 shown in Table 3 in the same manner as described above.
3-O and the compounds for comparative examples 3-a to 3e were obtained. Example 1 Amphoteric Compounds 1-A to 1-G, 2-A to 2-G, and 3
-Addition of 0.4 to 100 parts of pulp for A to 3-L
Parts and bentonite were set to 0.2 part with respect to 100 parts of pulp, and a handsheet was obtained using a handsheet machine manufactured by Noble & Wood Co. under the following conditions. Pulp: recycled corrugated paper, Canadian Standard Freeness (CSF) 360 ml Additives and order of addition The additives were added to 100 parts of the pulp in the following order. 1. Aluminum sulfate (Sumitomo Chemical Co., Ltd.) 0.5 parts 2. Amphoteric compounds 1-A to 1-G, 2-A to 2-G, 3
0.4 parts of each compound of -A to 3-L 3. Bentonite (Kunigel VA, Kunimine Industry Co., Ltd.) 0.2 parts Papermaking pH: 6.0 Drying condition: drum dryer (100 ° C, 90 seconds) After humidifying the paper for 24 hours under the conditions of 20 ° C and 65% relative humidity, the burst strength is measured, and DDT (Dynamic Drainage Test) is performed using pulp slurry during papermaking.
(Drainage test)). Table 4 shows the results. In addition, these measurements were performed according to the following method. Burst strength: JIS P-8131 DDT: Tappir Journal Vol. 56 No. 10 (1973) Using a device similar to "Dynamic Drainage Jar" described on page 46 of 1963, 800 ml of pulp slurry was about 7.5 cm in diameter. Pour into a container and open the lower cock while stirring at 800 rpm.
It is filtered through a 0-mesh wire gauze and measures the time until the filtrate volume becomes constant. It can be used for evaluation of drainage, and the shorter the time, the better the drainage. Here, the time required for the filtrate amount to reach 200 ml was measured. Example 2 Amphoteric compounds 1-A to 1-G, 2 based on 100 parts of pulp
0.1 parts of each of -A to 2-G and 3-A to 3-L and 1.0 part of bentonite were added, and a handsheet was obtained using a handsheet machine manufactured by Noble & Wood Co. under the following conditions. . Pulp: Waste corrugated paper, CSF 420 ml Additives and order of addition The additives were added to 100 parts of the pulp in the following order. 1. Aluminum sulfate 1.0 part 2. Rosin emulsion (New Four 100, manufactured by Dick Hercules Co., Ltd.) 0.2 part 3. Bentonite (Fuji-mark, manufactured by Toyojun Yoko Co., Ltd.) 1.0 part 4. Amphoteric compound obtained above 1-A to 1-G, 2-A to
2-G, each compound of 3-A to 3-L 0.1 part Papermaking pH: 5.0 Drying condition: Drum dryer (110 ° C, 90 seconds) Hand-made paper was obtained in the same manner as in Example 1, and The burst strength and DDT were measured and the results are shown in Table 5. Example 3 Amphoteric compounds 1-H to 1-J, 100 parts of pulp
-H to 2-J, 0.05 to each of 3-M to 3-O, and 0.5 part of bentonite were added, and a hand-made paper was obtained under the following conditions using a hand-made machine manufactured by Noble and Wood. . Pulp: Waste corrugated paper, CSF 350 ml Additives and order of addition The additives were added to 100 parts of the above pulp in the following order. 1. 1.0 part of aluminum sulfate 2. 0.5 part of bentonite (Organozove, Allied Colloid) 3. Polymers 1-H to 1-J and 2-H to 2- obtained above
J, each compound of 3-M to 3-O 0.05 part Papermaking pH: 5.5 Drying condition: drum dryer (100 ° C., 90 seconds) Hand-made paper was obtained in the same manner as in Example 1, and the burst strength was obtained. And DDT were measured, and the results are shown in Table 6. Comparative Example 1 Papermaking and measurement were performed in the same manner as in Example 1 except that bentonite was not used, and the results are shown in Table 7. Comparative Example 2 Papermaking and measurement were conducted in the same manner as in Example 2 except that bentonite was not used, and the results are shown in Table 8. Comparative Example 3 Papermaking and measurement were performed in the same manner as in Example 3 except that bentonite was not used, and the results are shown in Table 9. Comparative Example 4 In Example 1, amphoteric compounds 1-A to 1-G, 2-
Instead of using A to 2-G and 3-A to 3-L, 1-a to
Papermaking and measurement were performed in the same manner except that 1-c, 2-a to 2-c and 3-a to 3-c were used, and the results were shown in Table 10.
Shown in Comparative Example 5 In Example 3, amphoteric compounds 1-H to 1-J, 2-
1-d, 1- in place of H ~ 2-J, 3-M ~ 3-O
Papermaking and measurement were performed in the same manner except that e, 2-d, 2-e, 3-d and 3-e were used, and the results are shown in Table 11. Effects of the Invention According to the present invention, when an amphoteric compound having acrylamide and / or methacrylamide as a polymerization component and bentonite are used in combination as an additive, drainage is improved as compared with a combination of a cationic compound and bentonite, In addition, the strength of the paper can be prevented from lowering. In particular, the above general formula (II
It can be seen that when an amphoteric compound using [I] or [IV] is used, the effect of improving drainage is further improved. Further, since the molecular weight of the polymer of the amphoteric compound is 100,000 to 1,000,000, a decrease in paper strength which occurs when the molecular weight is more than 1,000,000 is not seen, which is preferable. Further, not only the amphoteric compound obtained by polymerization of the monomer alone, but also the Hoffman reaction, even when a Mannich reaction is performed on an anionic acrylamide polymer to introduce a cationic group, even if hydrolysis to the acrylamide component occurs, The cationic group can be introduced with a small and substantially no effect on the amount of anionic groups of the initial polymer thereby, and the content of the anionic and cationic groups of the amphoteric compound can be adjusted to a desired value. It is easy to control within the range and to increase the precision, and therefore, when these reactions are actually applied to a polymer such as an anionic acrylamide polymer to produce an amphoteric compound, these anionic groups, cations The accuracy of its performance based on the group can be increased, and when the amphoteric compound is used in paper additives It is possible to exhibit a stable performance. In addition, not only amphoteric compounds obtained by polymerization of monomers alone, but also polymer reactions utilizing the Hoffman reaction or Mannich reaction, the polymers that cause the reaction include (meth) acrylamide and anionic monomers. It is obtained as a water-soluble polymer using a monomer having high water-solubility, and it is possible to prevent the degree of water-solubility from being changed by using other monomers in combination, thereby facilitating the production.

Claims (1)

(57) [Claims] An amphoteric compound which is a polymer having an average molecular weight of 100,000 to 1,000,000 and is amphoteric, and a method for producing paper using an additive containing bentonite, wherein the polymer is acrylamide and / or methacrylamide, An anionic polymer containing an anionic monomer in a polymerization component, wherein the amphoteric compound is a Hoffman reaction product or a Mannich reaction product of the anionic polymer, or the amphoteric compound is acrylamide and / or methacrylamide. And a polymer containing an anionic vinyl monomer and a cationic vinyl monomer in a polymerization component. 2. As the cationic vinyl monomer, the following general formula [I]
The method for producing paper according to claim 1, wherein the compound represented by the formula (1) is used. General formula [I] (Where A is oxygen or NH, n is an integer of 2 to 4, R ₁
Represents H or a methyl group, and R ₂ and R ₃ represent the same or different lower alkyl groups. ) 3. The following general formula (II) as a cationic vinyl monomer
The method for producing paper according to claim 1, wherein the compound represented by the formula (1) is used. General formula (II) (Where A is oxygen or NH, n is an integer of 2 to ₄ , R ₄
Represents an H or methyl group, R ₅ , R ₆ and R ₇ represent the same or different lower alkyl groups, and X ⁻ represents an anion group. ) 4. The following general formula (II)
The method for producing paper according to claim 1, wherein the compound represented by the formula (I) is used. General formula (III) (Where A is oxygen or NH, n is an integer of 2 to 4, R ₈
Represents an H or methyl group, R ₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ represent the same or different lower alkyl groups, and X ⁻ and Y ⁻ represent the same or different anion groups, respectively. ) 5. The following general formula (IV) as a cationic vinyl monomer
The method for producing paper according to claim 1, wherein the compound represented by the formula (1) is used. General formula (IV) (Where A is oxygen or NH, n is an integer of 2 to 4, R
₁₄ is H or a methyl group, R ₁₅ and R ₁₆ are the same or different lower alkyl groups, and X ⁻ is an anion group. ) 6. 2. The method for producing paper according to claim 1, wherein the anionic group of the amphoteric compound is introduced by using acrylic acid and / or methacrylic acid as a polymerization component of the polymer. 7. 2. The method for producing paper according to claim 1, wherein the anionic group of the amphoteric compound is introduced by using itaconic acid as a polymerization component of the polymer. 8. 2. The method for producing paper according to claim 1, wherein the anionic group of the amphoteric compound is introduced by using maleic acid as a polymerization component of the polymer. 9. The method for producing paper according to claim 1, wherein the average molecular weight of the polymer is from 300,000 to 800,000.