JPS616395A - Aqueous enhancement in papermaking - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for increasing the speed of draining water on a wire in the paper manufacturing industry, increasing the efficiency of water extraction in a Sorespert, and facilitating drying.

(Prior Art) There are three stages of dehydration in the papermaking process: V-1 over-dehydration in a wire, compression dehydration in a press roll, and evaporation dehydration in a dryer. The quality of these dewatering operations not only affects manufacturing costs, but also the production volume. In the case of paperboard in particular, the basis weight is high and dewatering is difficult, so reactor water resistance is a big problem. For this reason, in the case of paperboard, it has been common practice for a long time to use a reactor water quality improver. As the water quality improver, I-lyethylenimine, polyamide polyamine, cationic polyacrylamide, etc. are used. Although these polymers initially showed some effectiveness, their effectiveness gradually declined as the quality of the raw pulp deteriorated and the system became more polluted due to increased reuse of water to rationalize water use. ing. For this reason, cationic acrylamide with a high degree of polymerization has come to be used, but although this improves freeness and increases the F water velocity in the wire, it does not necessarily improve dewatering in the press part; It may even get worse. A copolymer of methacrylate monomer H30H3 and acrylamide was also applied, but this did not have the expected effect.

(Objective of the Invention) It is an object of the present invention to exhibit an excellent reactor water effect compared to these conventional polymers, and to improve the yield of 1D/Guruzo fibers.

(Problems to be Solved by the Invention) The present invention is structurally very similar to the above-mentioned methacrylic monomer, but its properties and effects are completely different. The polymerization rate of conventional methacrylic monomers is significantly faster than that of acrylamide. Therefore, in the copolymerization of methacrylate and acrylamide, the polymerization of methacrylate takes precedence, producing a polymer with a high degree of cation substitution, and as the reaction progresses, the polymerization of acrylamide advances and the degree of cation substitution decreases, and at the end of the reaction almost no It is thought that only acrylamide was polymerized. The polymer produced in this way is a mixture of polymers with extremely non-uniform degrees of substitution, and it is assumed that most polymer molecules have an extremely low degree of cation substitution, with some having almost no degree of substitution, and this may be due to the p-water effect. This is thought to be the cause of the deterioration.

Although the cationic monomer used in the method of the present invention is structurally very similar to the methacrylate monomer, the properties of the copolymerized polymer are completely different, and it has an extremely uniform distribution of the degree of substitution. The idea is to take advantage of its properties and add it to slurry to significantly improve the furnace water properties during the papermaking process.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides (A) a general formula (wherein R1+R2 represents an alkyl group having 1 to 2 carbon atoms, and R3 is hydrogen or a carbon number represents 1 to 2 alkyl groups,
(X- represents an anion) A copolymer having a monomer content of 5 mol/100 mol/(B) and an acrylamide content of 0 to 95 mol/0.005 to 0. By adding .5% to paper stock, it improves the furnace water properties during the papermaking process and also improves the yield of Gulde fiber.

(Effect) Generally, the higher the degree of cation substitution, the better the water filtering effect. On the other hand, the yield effect is most excellent when the degree of substitution is 5 to 15 molar, and decreases as the degree of substitution increases. Furthermore, the Canadian freeness value also tends to decrease as the degree of substitution increases. As the degree of substitution increases, the cost of the drug also increases, so for practical use, a degree of substitution of 5 to 40 molar would be appropriate. It is appropriate to determine the optimum number of moles depending on the quality of the raw material used in the paper mill and the Furukawa ratio of water.

Used in the present invention. 15 The amount of remer added varies depending on the desired effect, the properties of the paper stock, and the ratio of recycled water, but in general, a polymer with a high degree of polymerization is appropriate for paper stock with extremely low freeness or for factories that use a large amount of recycled water. Therefore, the appropriate amount of the polymer with a high degree of polymerization to be added is about 0.005 to 0.05%. In addition, for paper stocks with relatively high freeness, it is desirable to add 0.01 to 0.1% of z IJ mom, which has a high cation dispersion and a low degree of polymerization, in order to prevent deterioration of the texture. The addition location is preferably as close to the machine as possible, and where the added polymer is immediately and uniformly dispersed into the paper stock, and suitably the inlet of the fan 2 or the inlet of the final screen.

(Example) (+) Waste newspaper was disintegrated using an experimental beater to obtain paper stock. Add 1% of sulfuric acid band to Gluzo, add 0.003% of reactor water quality improver to this, and make a tsubo of 3009/m2.
Paper was made using a tK tattoo standard machine, and the paper was sandwiched between blankets and passed through press rolls twice to dehydrate it. The second time, the direction of the sheet was rotated by 180 degrees. The stress conditions were adjusted in advance so that the water content without polymer addition was 60 inches. The weight of the f-less dehydrated sheet was immediately measured, and after drying, it was weighed again to calculate the moisture content of the sheet. A comparison was made by displaying 100 times the value divided by the water content when no chemicals were added as a water content index. Based on the standard deviation, it was recognized that there was a significant difference when this value was 0.15 or more. Also, a difference of 0.3 in these numbers results in a cost reduction of more than 5% in the required amount of steam. This is shown in Table 1. In this table, the invention product 1...acrylate 5molti R1+ R2+
R3 is CH3 仝2...〃
15 molti R1+ R2+ R3 is CH3 to 3... 15 molti R1r R2 is CH3, R3 is C2H5 to 4...
〃35 molti R1+ ``2 + ''3 ke CH3 仝 5・ 〃35 molti R1 and R2 are C2H5 ・R3 is CH3 Invention product 6 Acrylate 60 7 ruti R1r R2 and R3 are CH3 仝 7... 〃100 molti RI + R2+ R3 is CH3 Cationic polyacrylamide A Degree of cationization 1
00 molti B 〃 60 molti c tt 30 molti methacrylate co-combination A methacrylate 10 molti n B LL
Table 1 (Effects) The method of the present invention has very good results as shown in Table 1 above, and its effects are satisfactory. That is, the copolymer according to the invention contains acrylate 5
It is a copolymer consisting of ~100 moles and acrylamide 0 to 95 moles, and has a molecular weight of 0.005 to 0.05 based on the paper stock.
% is found to be appropriate.

Claims (1)

[Claims] (A) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 and R_2 are alkyl groups having 1 to 2 carbon atoms, R
_3 represents hydrogen or an alkyl group having 1 to 2 carbon atoms, and
^- indicates an anion) A copolymer having a monomer content of 5 mol% to 100 mol% and (B) an acrylamide content of 0 to 95 mol% is added to the paper stock. A method for improving freeness in paper manufacturing, characterized by: