JP2001252673A - Method for preventing slime trouble at paper/pulp production stage water system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the slime trouble at a paper/pulp production stage water system by using an agent more high in safety. SOLUTION: In the slime trouble preventing method at the paper/pulp production stage water system, an effective amount of more than one polymers of dicarboxylic acid or polyphosphinocarboxylic acid selected from maleic acid polymerization product, acrylic acid-2-acryloyl amino-2-methyl-1-propane sulfonic acid/hypophosphorous acid addition polymerization product and its salt and bis(poly-2-carboxyethyl)phosphinic acid and its salt is added to the paper/pulp production stage water system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing slime in a water system for paper and pulp production. More specifically, the present invention relates to a method for preventing slime damage in a process water system in the paper and pulp manufacturing industry, mainly in a papermaking process water (white water) system.

[0002]

2. Description of the Related Art In a paper making process water system in the paper and pulp manufacturing industry, slime is likely to cause an obstacle. Slime is formed by microorganisms such as bacteria and fungi adhering to the walls of tubes and vessels in aqueous systems and secreting sticky substances. The slime peels off from the tube wall or vessel wall, and mixes with the papermaking raw material or clogs the piping, causing problems such as a decrease in quality of a product and a decrease in production efficiency.

[0003] In order to prevent such slime-induced problems, various bactericides have been used. However, many of these disinfectants have an adverse effect on the environment or have a fear of adverse effects, and the use of the agent itself has been regulated. In particular, agents that exhibit an excellent bactericidal effect tend to have environmentally unfavorable properties. Therefore, there is a need for a drug with higher safety in order to prevent slime-induced damage.

[0004] The polymer of dicarboxylic acid or polyphosphinocarboxylic acid as an active ingredient of the present invention is known as a known anticorrosive or scale inhibitor, but is known to have a slime damage preventing effect. Absent.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to effectively prevent slime damage in an aqueous system of paper and pulp manufacturing processes by using a safer chemical.

[0006]

Means for Solving the Problems The inventors of the present invention provide:
Under such circumstances, there is a concern that slime-related obstacles directly affect the quality of products, including pulp from paper raw materials that will become products, and so-called slime generation in paper and pulp manufacturing process water systems, which are special slime-producing water systems. We conducted intensive research on the effect of preventing obstacles. As a result, by adding a specific dicarboxylic acid or polyphosphinocarboxylic acid polymer, which has not been used in the water system of the paper and pulp manufacturing process as an additive containing a conventional slime inhibitor, to this water system, Surprisingly, it was found that the slime was prevented from adhering to the pipe wall, vessel wall, wire or roll without adversely affecting the slime, and the slime obstacle preventing effect was obtained, and the present invention was completed. .

Thus, according to the present invention, (A) a maleic acid polymer (molecular weight: 800 to 1,000), (B) a general formula (I):

[0008]

Embedded image

[Where X is

[0010]

Embedded image

Wherein Z is —CONHC (CH ₃ ) ₂ CH ₂
An SO ₃ H group, a + b is from 4 to 16), wherein two repeating units represented by the following formulas are regularly or randomly bonded:
Y is a hydrogen atom, a —SO ₄ H group or a —HPOH group, and W is a hydrogen atom or a —XY group]. 2-acryloylamino-2-methyl-1-propanesulfonic acid; Hypophosphorous acid addition polymer and a salt thereof, and (C) a general formula (II):

[0012]

Embedded image

Wherein m + n is 4 or 16; a dicarboxylic acid or polyphosphinocarboxylic acid polymer selected from bis (poly-2-carboxyethyl) phosphinic acid and salts thereof. A method for preventing slime in a paper / pulp manufacturing process water system, characterized by adding an effective amount of at least one species to the paper / pulp manufacturing process water system.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The maleic acid polymer (A) used in the present invention has a molecular weight of about 800 to 1000, a specific gravity (20 ° C.) of about 1.1 to 1.2, and a kinematic viscosity ( (25 ° C.) about 10 to 40 mm ² / sec. Such compounds are known scale inhibitors and are commercially available, such as BioLab
Belclene (registered trademark) 200 manufactured by the company can be suitably used.

(B) Acrylic acid used in the present invention
The 2-acryloylamino-2-methyl-1-propanesulfonic acid / hypophosphorous acid addition polymer is represented by the general formula (I), and has a phosphinico group (bonded to a phosphorus atom) in the formula.
A salt in which some or all of the hydrogen atoms of the hydroxyl group have been replaced with alkali metal atoms may be used. Further, a part or all of the hydrogen atoms of the carboxyl group and the hydrogen atoms of the sulfonic acid group of the substituent Z may be replaced with an alkali metal atom. Among them, the general formula (I) Z is in _{-CONHC (CH 3) 2 CH 2} SO 3 Na group in which acrylic acid-2-acryloyl-amino-2-methyl-1
The sodium salt of a sodium propane sulfonate / hypophosphorous acid addition polymer is particularly preferred in view of the slime damage preventing effect. This compound is a known scale inhibitor and is commercially available, such as Belclene® 40 from BioLab.
0 can be suitably used.

The (C) bis (poly-
2-carboxyethyl) phosphinic acid has the general formula (II)
And a salt in which part or all of the hydrogen atoms of the hydroxyl group (bonded to the phosphorus atom) of the phosphinico group in the formula may be replaced with an alkali metal atom. Further, some or all of the hydrogen atoms of the carboxyl group may be replaced with alkali metal atoms. Among them, bis (poly-2-carboxyethyl) phosphinic acid is particularly preferred in terms of the effect of preventing slime damage. Such compounds are known anticorrosives and antiscalants and are commercially available, such as Belclene® 5 from BioLab.
00 [m + n of general formula (II) is 4] and BioLab
(D) Belsperse (registered trademark) 164 [general formula (I
M + n in (I) is 16].

In the method of the present invention, an effective amount of at least one polymer of a dicarboxylic acid or a polyphosphinocarboxylic acid selected from (A), (B) and (C) as an active ingredient is added to paper.・ Add to pulp production process water system. The effective amount varies depending on the state of the aqueous system of the paper / pulp production process and the type of the active ingredient, but is usually 3 to 250 mg / l, preferably 20 to 100 mg / in terms of the active ingredient concentration in the aqueous system.
l. When the concentration of the active ingredient is in the range of 3 to 250 mg / l, an excellent slime disorder preventing effect can be obtained.

In the method of the present invention, known bacteriostatic and bacteriostatic agents can be used in combination as long as the effects of the present invention are not impaired.

The mode of adding the active ingredient in the method of the present invention is not particularly limited, and the active ingredient itself can be added as it is or as an aqueous solution optionally diluted with water. The above-mentioned commercially available product is a 35 to 50% by weight aqueous solution, and can be used as it is or after further dilution with water.

In general, since the water system in the paper / pulp production process is a circulation system, the location where the active ingredient is added is not particularly limited.
It is preferable to select the place of addition so that the active ingredient is uniformly dispersed in the aqueous system. Moreover, the existing drug addition equipment may be diverted as it is without introducing new equipment for adding the active ingredient.

[0021]

EXAMPLES The present invention will be specifically described by the following test examples, but the present invention is not limited to these test examples.

The drugs used in the test examples are shown below. Drug A: 50% by weight aqueous solution of maleic acid polymer (as described above)
Belclene 200), Drug B: 50% by weight aqueous solution of sodium acrylate-2-sodium acryloylamino-2-methyl-1-propanesulfonate / sodium hypophosphite addition polymer (described above)
Belclene 400) Drug C: 35% by weight aqueous solution of bis (poly-2-carboxyethyl) phosphinic acid (Belgium 500 described above) Drug D: 40% by weight aqueous solution of bis (poly-2-carboxyethyl) phosphinic acid (Belsperse 164 described above)

Drug E: 40 of sodium polyacrylate
% By weight aqueous solution (used in comparative examples) Drug F: 3: 1 mixture of 2-methyl-5-chloro-1,2-isothiazolin-3-one and 2-methyl-1,2-isothiazolin-3-one Composition comprising 25 parts by weight, 25 parts by weight of 2-bromo-2-nitro-1,3-diacetoxypropane and 50 parts by weight of diethylene glycol (used in Reference Example) Among the above drugs, drug E is used as a scale inhibitor. The compound being used, Drug F is a composition used as a bactericide.

Test Example 1 (Test for confirming the effect of preventing slime damage) A slime-forming bacterial solution 0.1 cultured from slime collected from a white water system of a certain paper mill in a liquid standard medium placed in an L-shaped tube.
ml (viable cell count: 1.0 × 10 ⁵ cells / ml or more) was added, followed by the addition of a reagent having a predetermined concentration shown in Table 2. The time when this reagent was added was defined as the start of the test. After shaking the L-shaped tube for 4 days, the amount of slime adhered was visually observed, the slime adhered amount was evaluated in three stages based on the evaluation criteria shown in Table 1, and the number of viable bacteria was also measured. The results are shown in Table 2 together with the names of the reagents and the amounts added.

[0025]

[Table 1]

[0026]

[Table 2]

Test Example 2 (Test for confirming the effect of preventing slime in white water in the papermaking process) 280 m along the inner wall of a 500 ml beaker
An mx100 mm plastic wire was fixed, collected from a paper mill white water system, and filtered beforehand with white water (pH:
(7.0, SS: 353 ppm), and the mixture was stirred with a jar tester equipped with a thermostat at 30 ° C. and 50 rpm. Next, the reagents at a predetermined concentration shown in Table 4 were added. The time when this reagent was added was defined as the start of the test.

The white water was changed once a day. Immediately after the white water was changed, the same type and the same amount of the reagent as those added at the start of the test were added. The number of viable bacteria in the white water was measured at the start of the test, 30 minutes after the start of the test, and immediately before the white water exchange. Also, two days after the start of the test, the slime adhered to the plastic wire was visually observed, and the slime adhered amount and the slime adhered area ratio were evaluated in five steps based on the evaluation criteria shown in Table 3 (Examples 1 to 6). ). The results are shown in Tables 4 and 5 together with the names of the reagents and the amounts added.

A slime damage prevention effect confirmation test was carried out in the same manner as in Examples 1 to 6, except that the medicine F was used instead of the medicines A to D, and the addition was made 30 minutes before the replacement of white water.
(Reference example). At the start of the test, the number of viable bacteria in the white water was measured immediately before the addition of the drug F and immediately before the replacement of the white water. Two days after the start of the test, the slime adhered to the plastic wire was visually observed and evaluated in the same manner as in Examples 1 to 6 (Reference Example). The obtained results are shown in Tables 4 and 5 together with the names of the reagents and the amounts added.

[0030]

[Table 3]

[0031]

[Table 4]

[0032]

[Table 5]

[0033]

According to the method of the present invention, a polymer of dicarboxylic acid or polyphosphinocarboxylic acid having higher safety is added to the aqueous system of the paper / pulp production process.
Even if a bactericidal effect is not obtained, an excellent slime disorder preventing effect can be obtained. Therefore, it can be said that the method for preventing slime damage of the present invention is a very useful method from an environmental point of view.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C02F 1/50 532 C02F 1/50 532K A01N 57/18 A01N 57/18 F C08F 220/06 C08F 220/06 220/58 220/58 D21H 21/04 D21H 21/04 (72) Inventor Yoshio Ueda 2-10-15 Higashiawaji, Higashiyodogawa-ku, Osaka F-term in Katayama Chemical Industry Laboratory Co., Ltd. 4H011 AA02 BA06 BB17 DA12 DD01 DD07 4J100 AJ02P AM21Q BA55H BA56Q BA63H CA01 CA04 CA27 CA31 DA38 HA61 HB57 JA13 JA21 4L055 AG32 AG36 AG70 AG71 AG90 AG92 AH21 BD15 EA25 FA20

Claims (2)

[Claims] (A) a maleic acid polymer (molecular weight: 800)
To 1000), (B) general formula (I): [Wherein X is (Wherein, Z is a —CONHC (CH ₃ ) ₂ CH ₂ SO ₃ H group, a
+ B is 4 to 16), a group in which two repeating units represented by the following formulas are regularly or randomly bonded, Y is a hydrogen atom,
—SO ₄ H group or —HPOH group, W is a hydrogen atom or —XY group]. 2-acryloylamino-2-methyl-1-propanesulfonic acid;
Hypophosphorous acid addition polymer and its salt, and (C) a general formula (II): Wherein m + n is 4 or 16; and at least one polymer of a dicarboxylic acid or a polyphosphinocarboxylic acid selected from bis (poly-2-carboxyethyl) phosphinic acid and salts thereof. A method for preventing slime in a paper / pulp manufacturing process water system, comprising adding an effective amount to a paper / pulp manufacturing process water system. 2. The method for preventing slime damage according to claim 1, wherein the effective amount is 3 to 250 mg / l in terms of the concentration of the active ingredient in the paper / pulp production process water.