JP4589495B2 - Drainage improvement method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for improving drainage, and more particularly to a method for improving drainage in which a polymerization polymer and a polyethyleneimine compound are used in combination in a papermaking raw material before paper making.
[0002]
[Prior art]
When manufacturing paper, various approaches can be considered to improve productivity, but the drainage on the wire and the moisture content after the dehydration press are lowered, the papermaking speed is increased, and the steam of the dryer is increased. In order to reduce the amount used and improve productivity, it is a drainage improver that is added to the papermaking raw material before papermaking. Polyethyleneimine has been used for a long time, but there are drawbacks such as a large amount added and costly, and the use of foamed water, and various improved inventions have been made. For example, a method of adding a polyacrylamide Hoffman reaction (JP-A-2-175706), a method of adding a polyvinylamine polymer (JP-A 63-165212), or a benzyl group-containing acrylic cationic copolymer. A method of using a polymer and colloidal silica in combination (Japanese Patent Laid-Open No. 9-279498) is disclosed. However, each of these drugs has problems. That is, the Hoffman reaction product has poor storage stability, the poly (vinylamine) polymer has a complicated manufacturing process, and the method of using a benzyl group-containing acrylic cationic copolymer and colloidal silica together uses an optimal colloidal silica. In other words, very strict quality control is required.
[0003]
On the other hand, in order to synthesize polyvinylamine polymer, after polymerizing N-vinylcarboxylic acid amide, or polyvinylamidine polymer after copolymerization of N-vinylcarboxylic acid amide and acrylonitrile, each side chain is synthesized. The N-acyl group was hydrolyzed with acid or alkali to produce a primary amino group or amidine group. However, in this method, since the hydrolysis reaction can be performed only after polymerization, the reaction conditions are inevitably severe.
[0004]
Attempts have also been made to improve polyethyleneimine as a drainage improver. Polyethyleneimine has a very high calculated ion equivalent, but it is estimated that about half to 60% of the cationic groups are actually effective for neutralizing and coagulating the surface charge of the pulp. It is presumed that the cationic group exists in the main chain, and that every two carbon atoms are bonded, the interaction between the cationic groups is likely to occur, and the function does not function effectively. In order to improve this, in recent years, attempts have been actively made to apply a polymer in which ethylene oxide or propylene oxide is added after polymerization of polyethyleneimine and the ion equivalent is kept low.
[000 5 ]
However, the cationic group by denaturing these polyethyleneimine now look I to function effectively, although the charge neutralization of the pulp surface became effective, functions as a drainage aid can not be said yet sufficiently . This is because the function required as a drainage improver is required to agglomerate the pulp and promote drainage on the wire. For this purpose, a polymerized polymer having a higher molecular weight than that of polyethyleneimine produced by polymerization of a vinyl monomer is inevitably required. Polyethyleneimine has a low molecular weight and is inevitably disadvantageous for agglomeration with “large” floc formation of the pulp that develops due to cross-linking adsorption.
[0006]
[Problems to be solved by the invention]
The purpose of the present invention is to improve and reduce the relatively high addition amount, which was a disadvantage of polyethyleneimine, and to promote water drainage on the wire when polyethyleneimine is used as a drainage improver. To do.
[000 7 ]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the following inventions have been achieved. That is, according to the invention of claim 1 of the present invention, the repeating unit consisting of a diallylamine monomer and / or a monomer represented by the following general formula (2) is contained in 5 to 100 mol% in the papermaking raw material before papermaking. And a polymerization polymer composed of 0 to 95 mol% of acrylamide units and a polyethyleneimine compound which is an ethylene oxide and / or propylene oxide adduct represented by the following general formula (1): This is a method for improving drainage.
[Chemical 1]
R ₁ represents hydrogen or a methyl group , p represents 0 to 1,000, and r represents 10 to 10,000.
[Chemical 2]
R ₃ is hydrogen or methyl, R ₄ is methyl or ethyl, R ₅ is methyl, ethyl or benzyl, R ₆ is hydrogen, methyl or ethyl, A is oxygen or NH, B is alkylene or alkoxylene group C ₂ ~C _3, X is an anion [000 8]
The invention according to claim 2 is that the polymerization-based polymer comprises a diallylamine monomer and / or a monomer represented by the general formula (2) consisting of 10 to 30 mol% and acrylamide 70 to 90 mol%. the aqueous salt solution mer mixture that soluble ionic polymeric dispersant presence, a cationic water-soluble polymer composed of manufactured particle size 100μm or less of the polymer particles by dispersion polymerization in the salt solution The drainage improvement method according to claim 1 , wherein:
[000 9 ]
DETAILED DESCRIPTION OF THE INVENTION
The polyethylenimine compound used in the present invention is a polyethylenimine modified by adding an alkylene oxide. That is, an oxyalkylene chain is produced from the amino group hydrogen at the end of the polymer or the amino group hydrogen in the main chain. By modifying in this way, the polyethyleneimine is hydrophilized to improve foaming properties, and the cation equivalent per weight of the polymer is reduced.
[00 10 ]
Examples of the polymer used in combination include a polymer containing a dimethyldiallylammonium salt structural unit. Examples thereof are a homopolymer of dimethyldiallylammonium chloride or a copolymer with a nonionic monomer. Examples of nonionic monomers are meth) acrylamide, N, N-dimethylacrylamide, vinyl acetate, acrylonitrile, methyl acrylate, 2-hydroxyethyl (meth) acrylate, diacetone acrylamide, N-vinyl pyrrolidone, N -Vinylformamide, N-vinylacetamide and the like. Moreover, it is also possible to copolymerize an anionic monomer, and in this case, it becomes an amphoteric polymer. Examples of the anionic monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, vinyl sulfonic acid, vinyl benzene sulfonic acid, or acrylamide 2-methylpropane sulfonic acid. The molar ratio of these monomers is 5-100 mol% for dimethyldiallylammonium salt monomers, 0-95 for nonionic monomers, and 0-30 mol% for anionic monomers. Preferably, the dimethyldiallylammonium salt monomer is 10 to 100 mol%, the nonionic monomer is 0 to 90, and the anionic monomer is 0 to 20 mol%. The most preferred composition is dimethyl diallylammonium salt monomer and acrylamide.
[00 11 ]
A homopolymer of an acrylic monomer or a copolymer with another monomer can also be used. Examples of the acrylic cationic monomer include tertiary amino group-containing monomers such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylamide. As quaternary ammonium group-containing monomers, (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxy 2-hydroxypropyltrimethylammonium chloride, (meth) acryloylaminopropyltrimethylammonium chloride, (meth) acryloyl Examples thereof include oxyethyldimethylbenzylammonium chloride, (meth) acryloyloxy 2-hydroxypropyldimethylbenzylammonium chloride, and (meth) acryloylaminopropyldimethylbenzylammonium chloride. The copolymerization molar ratio of these acrylic monomers is 5 to 100 mol%, the nonionic monomer is 0 to 95 mol%, and the anionic monomer is 0 to 30 mol%, preferably acrylic. These are 10 to 100 mol% of the system monomer, 0 to 90 mol% of the nonionic monomer, and 0 to 20 mol% of the anionic monomer. The most preferred composition is an acrylic monomer and acrylamide.
[00 12 ]
The polymerization method can be synthesized by a known polymerization method such as an aqueous solution polymerization method, a water-in-oil emulsion polymerization method, a water-in-oil dispersion polymerization method, or a salt-water dispersion polymerization method. Among these, a polymerization method particularly preferably used is a dispersion polymerization method in an aqueous salt solution, which is a polymerized cationic water-soluble polymer produced by this method. A water-soluble polymer comprising a polymer dispersion dispersed in an aqueous salt solution can be produced according to JP-A-62-1251. The polymerization concentration by the dispersion polymerization method in an aqueous salt solution can be in the range of 5 to 50% by weight, preferably 20 to 40% by weight. Moreover, as reaction temperature, it can carry out in the range of 10-100 degreeC.
[00 13 ]
The radical polymerization initiator for initiating the polymerization can be polymerized by any of azo, peroxide and redox systems. Examples of oil-soluble azo initiators are 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexanecarbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2-methylpropionate) and the like are dissolved in a water-miscible solvent and added. Examples of water-soluble azo initiators include 2,2′-azobis (amidinopropane) dichloride, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] And dihydrochloride, 4,4′-azobis (4-cyanovaleric acid), and the like. Examples of redox systems include a combination of ammonium or potassium peroxodisulfate and sodium sulfite, sodium hydrogen sulfite, trimethylamine, tetramethylethylenediamine, and the like. Examples of peroxides include ammonium peroxodisulfate, hydrogen peroxide, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, succinic peroxide, and t-butylperoxy 2-ethylhexanoate. Can do.
[00 14 ]
The molecular weight of these polymerized polymers is 100,000 to 10 million, preferably 1 million to 10 million. Below 100,000, the cohesive force is insufficient and the drainage on the wire is lowered. Also, when it exceeds 10 million, the cohesive force does not change much, the solution viscosity becomes too high and the dispersibility deteriorates. Handling is also bad and there is no particular merit.
[00 15 ]
As the addition site of the primary amino group-containing cationic or amphoteric polymer used in the present invention, a screen inlet or outlet may be considered.
[00 16 ]
As the papermaking pH applicable to the method for improving drainage of the present invention, an excellent effect is exhibited in acidic papermaking to neutral papermaking as compared with other treatment methods. Therefore, there is a merit in the range of 4.0-9.0 as papermaking pH. The target paper product is a high-quality or medium-quality printing paper, or a paperboard such as a core base paper or a liner.
[00 17 ]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated in more detail with an Example and a comparative example, this invention is not restrict | limited to a following example, unless the summary is exceeded.
[00 18 ]
(Synthesis Example 1) A dimethyl ester in a 500 mL four-necked flask equipped with a thermometer, a stirrer, a nitrogen introduction tube, a monomer supply tube connected to a peristaltic pump (SMP-21 type, manufactured by Tokyo Rika Kikai Co., Ltd.) and a condenser Diallylammonium chloride (trade name DADMAC, 65% by weight, manufactured by Daiso) 18.6g, acrylamide (trade name, acrylic amide, 50% by weight, manufactured by Nitto Chemical) 30% by weight 20g, ion-exchanged water 107g, 0.18 g of 2-propanol as a chain transfer agent (0.3% per total monomer), 2 as a polymerization initiator, 5 g of 0.7% aqueous solution of 2-azobisamidinopropane dihydrochloride (0.25% per total monomer) was charged. While stirring the raw material mixture, the temperature was maintained at 42 ° C. and nitrogen was introduced to allow polymerization to proceed for 30 minutes. Then, 140 g of a 30 wt% aqueous solution of acrylamide was supplied into the flask at 0.58 g per minute for 4 hours. The molar ratio of DADMAC to acrylamide after the supply is finished is 10:90. After completion of the supply, 5 g of a polymerization initiator was added in 8 hours. After 12 hours from the start of polymerization, the heat retention was stopped and the polymerization was stopped. Thereafter, the weight average molecular weight was measured by a molecular weight measuring device (DLS-7000 manufactured by Otsuka Electronics Co., Ltd.) by a static light scattering method, and the cation equivalent (meq / g) of the polymer was measured by a colloid titration method. Further, by the same operation, 3 mol% (Comparative-1) of DADMAC, 30 and 60 mol% of each polymer (prototype-1 to prototype-3) were synthesized. The physical properties of each polymer are shown in Table 1.
[00 19 ]
(Synthesis Example 2) Each of acryloyloxyethyltrimethylammonium chloride (DMQ), acryloyloxyethyldimethylbenzylammonium chloride (DMABC), and acryloylaminopropyltrimethylammonium chloride (DMPQ) was prepared in the same manner as in the synthesis example. Mol% (Comparative- 2 to Comparative- 4 ), 10 mol%, 30 mol%, and 60 mol% polymers (trial-4 to prototype-12) were synthesized. Each physical property is shown in Table 1.
[00 20 ]
(Synthesis Example 3) 2.5 g of homopolymer of acryloyloxyethyltrimethylammonium chloride and 112.5 g of ammonium sulfate in a 1-liter separable flask equipped with a stirrer, thermometer, reflux condenser, nitrogen inlet tube, and nitrogen outlet tube And 335 g of deionized water were added to dissolve, and 11.7 g (40 mol%) of acrylamide, 20.0 g of 80% aqueous acryloyloxyethyldimethylbenzylammonium chloride and 22.3 g of acryloyloxyethyltrimethylammonium chloride were weighed into this. Deoxygenated by aeration, 0.15 cc of a 1% aqueous solution of 2,2′azobis-2-amidinopropane hydrochloride was added, and polymerization was carried out at 50 ° C. with stirring for 10 hours to obtain a polymer dispersion having a particle size of 5 microns. (Prototype-13) . After polymerization, each physical property was measured. The results are shown in Table 1.
[00 21 ]
Examples 1 to 13
The used newspaper was disaggregated into a 2% dispersion, and then beaten to 180 mL with a Canadian Standard Freeness (CSF) value display. This dispersion was diluted to 0.4% by weight and used for the drainage test. The prepared 0.4% by weight dispersion was collected in a 1000 mL graduated cylinder, and an ethylene oxide adduct of polyethyleneimine (molecular weight 120,000, cation equivalent 7.58 meq / g) was 400 ppm dry paper waste weight (hereinafter the same) 400 ppm. Add, stir by tilting the graduated cylinder five times, and then add 200 ppm of prototype- 1 to prototype- 13 as a polymer polymer and stir by tilting the graduated cylinder five times. Then, it put into the CSF tester and measured the amount of drainage. After that, the pulp remaining on the mesh of the CSF tester was filled in a double bottomed centrifuge tube with a filter cloth having a lower part of 100 mesh, and 3000 rpm for 5 minutes using a digital centrifuge. The pulp was dehydrated under the conditions (assuming a dehydration quilol on the machine). After measuring the weight of the dehydrated pulp, it is dried at 105 ° C. for 20 hours, and its weight is measured. Thereafter, incineration is performed at 900 ° C. for 2 hours, and the weight of the inorganic content is measured to measure the ash content yield. The results are shown in Table 2.
[00 22 ]
[Comparative Examples 1-8]
When only the trial productions-3, 6, 9, and 12 were added without adding polyethyleneimine, the test was conducted in the same manner as in Examples 1 to 13 with respect to the case where polyethyleneimine and Comparative-1 to Comparative-4 were added. The results are shown in Table 2.
[00 23 ]
Examples 14 to 26
Using the raw material for core base paper (pH 7.5, total ss 2.56%, ash content 0.13%) of corrugated cardboard, the drainage and dehydrating properties were the same as in Examples 1 to 13 under the conditions of neutral papermaking. Was tested. In all cases, the pH after chemical addition was around 7.2. The results are shown in Table 3.
[00 24 ]
[Comparative Examples 9-16]
In the case where only the prototypes-3, 6, 9, and 12 were added without adding the polyethyleneimine compound, the test was conducted in the same manner as in Examples 13 to 24 with respect to the case where the polyethyleneimine compound and Comparative-1 to Comparative-4 were added. went. The results are shown in Table 3.
[00 25 ]
Examples 27-39
Diluted with tap water to a pulp concentration of 0.4 wt% using papermaking raw material (pH 6.75, total ss content 2.55%, ash content 0.52%) for liner production, drainage and dehydration Sex was tested. As additive chemicals, amphoteric polyacrylamide paper strength enhancer, 0.2% by weight of paper raw material (the same applies hereinafter), emulsion rosin size 0.1%, sulfuric acid band 1.5%, polyethyleneimine ethylene oxide adduct (molecular weight) 220,000, cation equivalent 6.15meq / g), polymerization type polymer, prototype -1 prototype - was added at 13, respectively 15 seconds, or less were carried out in the same manner as in example 1 to 13 described above. In all cases, the pH after adding the chemical was around 6.4. The results are shown in Table 4.
[00 26 ]
[Comparative Examples 17 to 24]
In the case of adding only the trial productions-3, 6, 9, and 12 without adding the ethylene oxide adduct of polyethyleneimine, and in the case of adding the ethylene oxide adduct of polyethyleneimine and Comparative-1 to Comparative-4, Example 25- The test was conducted in the same manner as in 36. The results are shown in Table 4.
[00 27 ]
[Table 1]
DADMAC: diallyldimethylammonium chloride, DMQ: acryloyloxyethyltrimethylammonium chloride, ABC: acryloyloxyethyldimethylbenzylammonium chloride, DMPQ: acryloylaminopropyltrimethylammonium chloride, AAM: acrylamide [00 28 ]
[Table 2]
Filtrate: ml, pulp moisture content:%, ash yield:%
[00 29 ]
[Table 3]
Filtrate: ml, pulp moisture content:%, ash yield:%
[00 30 ]
[Table 4]
Filtrate: ml, pulp moisture content:%, ash yield:%

Claims (2)

A polymerization system comprising 5 to 100 mol% of repeating units composed of a diallylamine monomer and / or a monomer represented by the following general formula (2) and 0 to 95 mol% of acrylamide units in a papermaking raw material before papermaking A method for improving drainage, comprising adding a polymer and a polyethyleneimine compound which is an ethylene oxide and / or propylene oxide adduct represented by the following general formula (1).
R ₁ represents hydrogen or a methyl group , p represents 0 to 1,000, and r represents 10 to 10,000.

R ₃ is hydrogen or methyl, R ₄ is methyl or ethyl, R ₅ is methyl, ethyl or benzyl, R ₆ is hydrogen, methyl or ethyl, A is oxygen or NH, B is C ₂ -C ₃ alkylene group or alkoxylene group, X is an anion In the salt aqueous solution, the polymerization polymer is a diallylamine monomer and / or a monomer mixture composed of 10 to 30 mol% of the monomer represented by the general formula (2) and 70 to 90 mol% of acrylamide. , claim 1, wherein the soluble ionic polymeric dispersant presence in said salt solution is a cationic water-soluble polymer consisting manufactured particle size 100μm or less of the polymer particles by dispersion polymerization The method for improving drainage according to the above.