JPH1193091A - Pitch control agent and method for preventing pitch disturbance - Google Patents

Abstract

(57) [Summary] [Problem] To effectively control and prevent pitch disturbances in paper manufacturing process, prevent paper stains, defects, paper breakage, decrease in workability, etc. regardless of,
Provided are a pitch control agent and a method for preventing pitch failure that can be applied to a wide range. The pitch control agent comprises a water-soluble polymer having a vinylimidazoline unit represented by the general formula [1], and the water-soluble polymer is added to paper machine washing water. Pitch disturbance prevention method. In the formula, R ¹ , R ² and R ³ are hydrogen or an alkyl group having 1 to 3 carbon atoms. Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a pitch control agent and a method for preventing pitch disturbance. More specifically, the present invention relates to a pitch control agent and a pitch failure prevention method capable of effectively suppressing and preventing pitch disturbance in a paper manufacturing process.

[0002]

2. Description of the Related Art In the pulp and paper manufacturing process, pitch is generally used in wood, natural resins and gums released from pulp and paper, and also in pulp and paper manufacturing processes. It is a water-insoluble adhesive substance containing an organic substance as a main component and derived from additive chemicals. Pitch is colloidally dispersed during the pulp and paper manufacturing process, especially in white water, but has some external action, for example,
It is considered that the colloidal state is destroyed by a large shear force, a rapid change in pH, excessive addition of a sulfate band, etc., resulting in aggregation and giant growth. The agglomerated and enlarged pitch adheres to pulp and paper due to its adhesiveness.It also adheres to manufacturing equipment such as fan pumps, pipes, chests, wires, felts, and rolls, and then peels off, resulting in pulp and paper. Re-adhesion to the paper, causing deterioration of the quality due to the occurrence of stains and defects on the paper,
Pitch disturbances such as a decrease in productivity and workability due to the occurrence of paper breaks are caused. In recent years, as the use of chemicals has increased due to the diversification of paper and the use of water used in the process has been closed, pitch disturbances have occurred more frequently than ever, and the paper has become more complicated. Conventionally, various methods have been proposed or implemented for this pitch disturbance. For example, pitch control agents comprising dicyandiamide-formaldehyde condensates are widely known, but this pitch control agent is insufficient in the effect of preventing pitch disturbance. Also,
Polymers obtained from epichlorohydrin and dimethylamine are often expensive and have limited use. For this reason, there is a need for a pitch control agent and a pitch obstacle prevention method capable of effectively preventing the obstacle for a wide variety of pitches.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to effectively suppress and prevent pitch disturbances in the paper manufacturing process, to prevent paper stains, defects, paper breakage, and deterioration in workability, and to reduce pitch-causing substances. It is an object of the present invention to provide a pitch control agent and a method for preventing pitch failure that can be applied to a wide range regardless of the situation.

[0004]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the water-soluble polymer having a vinylimidazoline unit has excellent performance as a pitch control agent. It has been found that pitch disturbance can be effectively prevented by adding the polymer to the washing water of a papermaking machine, and the present invention has been completed based on this finding. A method has been proposed to increase the paper strength by adding a water-soluble polymer having a vinylimidazoline unit to a pulp slurry, but there is no known method of preventing pitch disturbance. That is, the present invention provides (1) a pitch control agent comprising a water-soluble polymer having a vinylimidazoline unit represented by the general formula [1],

Embedded image (Wherein, R ¹ , R ² and R ³ are hydrogen or an alkyl group having 1 to 3 carbon atoms), and (2) having a vinylimidazoline unit represented by the general formula [1]. A method for preventing pitch disturbance, comprising adding a water-soluble polymer to paper machine washing water,

Embedded image (Wherein, R ¹ , R ² and R ³ are hydrogen or an alkyl group having 1 to 3 carbon atoms). Further, as a preferred embodiment of the present invention, (3) the pitch control agent according to (1), wherein the water-soluble polymer having a vinylimidazoline unit is polyvinylimidazoline, and (4) the molecular weight of the water-soluble polymer having a vinylimidazoline unit. Wherein the pitch control agent according to item (1), which is 1,000 or more, (5) the method according to item (2), wherein the water-soluble polymer having a vinylimidazoline unit is polyvinylimidazoline, and
(6) The method for preventing pitch disturbance described in (2), wherein the molecular weight of the water-soluble polymer having a vinylimidazoline unit is 1,000 or more.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the general formula [1]
A water-soluble polymer having a vinylimidazoline unit represented by the following formula is used.

Embedded image In the general formula [1], R ¹ , R ² and R ³ are hydrogen or an alkyl group having 1 to 3 carbon atoms. The water-soluble polymer having a vinylimidazoline unit used in the present invention is not particularly limited, and is a homopolymer of 2-vinyl-2-imidazoline or a 1-, 4- or 5-lower alkyl-substituted product thereof and a vinylimidazoline of these vinylimidazolines. Copolymers can be used. Among these, polyvinylimidazoline, that is, a homopolymer of 2-vinyl-2-imidazoline can be particularly preferably used because it has a large pitch obstacle preventing effect. In the present invention, if necessary, a copolymer obtained by copolymerizing another copolymerizable monomer can be used. The other copolymerizable monomer is not particularly limited as long as it has an appropriate monomer reactivity ratio and a water-soluble copolymer is obtained, for example, (meth) acrylamide, styrene,
Methyl (meth) acrylate, ethyl (meth) acrylate, vinyl acetate, nonionic monomers such as N-vinyl pyrrolidone, (meth) acrylic acid, vinyl acetic acid, itaconic acid, maleic acid, a monomer having a carboxyl group such as fumaric acid or An alkali metal salt thereof, vinylsulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, a monomer having a sulfonic acid group such as styrenesulfonic acid or an anionic monomer such as an alkali metal salt thereof, dimethylaminopropyl (meth) acrylate, Examples include cationic monomers such as tertiary salts and quaternary ammonium salts such as dimethylaminoethyl (meth) acrylamide and dimethylaminopropyl (meth) acrylamide. These monomers can be copolymerized to form a tertiary or higher copolymer and used as an amphoteric polymer.

In the present invention, when the water-soluble polymer having vinylimidazoline units is a vinylimidazoline copolymer, it is preferably a copolymer having vinylimidazoline units in an amount of 50 mol% or more. By using a copolymer having a vinylimidazoline unit of 50 mol% or more, an excellent pitch obstacle prevention effect can be obtained. In the present invention, the molecular weight of the water-soluble polymer having a vinylimidazoline unit is preferably at least 1,000, more preferably at least 10,000, even more preferably at least 100,000. By using a water-soluble polymer having a vinylimidazoline unit having a high molecular weight, an excellent pitch obstacle preventing effect can be obtained. In the present invention, the polymerization method for obtaining these polymers is not particularly limited, and may be a known solution polymerization method, suspension polymerization method, emulsion polymerization method, or the like, depending on the monomers used and the solubility of the produced polymer. Can be manufactured. There is no particular limitation on the paper machine to which the method of the present invention is applied, for example, fourdrinier paper machine,
Examples include a twin-wire paper machine, a round paper machine, and a multilayer paper machine.

[0007] In the method of the present invention, there is no particular limitation on the paper machine washing water to which a water-soluble polymer having a vinylimidazoline unit is added, but it is added to the washing water at places where dirt is particularly likely to adhere, such as wires, rolls and felts. Is preferred. There is no particular limitation on the method of adding the water-soluble polymer having a vinylimidazoline unit, but a method of adding a water-soluble polymer having a vinylimidazoline unit to an aqueous solution, diluting it with shower water or water doctor addition water at each location, or A method of spraying a portion of a manufacturing apparatus to which a pitch adheres is preferable. In the present invention, the amount of the water-soluble polymer having a vinylimidazoline unit is not particularly limited, but the content of the water-soluble polymer should be 5 to 10,000 mg / liter with respect to shower water or water added with a water doctor. And more preferably 10 to 5,000 mg / liter. Alternatively, the addition amount of the water-soluble polymer is 1 g to 10 kg per ton of pulp fiber.
It can also be selected so that Raw pulp and paper to which the pitch control agent and the pitch obstacle prevention method of the present invention can be applied are not particularly limited, for example,
Various pulp such as groundwood pulp, mechanical pulp such as refiner mechanical pulp, chemical pulp such as kraft pulp, semi-chemical pulp, deinked pulp deinked from used paper, white paperboard, neutral high-quality paper, neutral medium-grade paper The present invention can be applied to various paper manufacturing processes such as thin-sheet printing paper, kraft paper, sanitary paper, and cardboard base paper. The mechanism of action of the pitch control agent and the pitch obstacle prevention method of the present invention is not clear, but by adding a water-soluble polymer having a vinylimidazoline unit to paper machine washing water, the surface of wires, rolls, felts, etc. becomes hydrophilic. It is thought that pitch disturbance is prevented by making it difficult to adhere hydrophobic pitch.

[0008]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Example 1 In the papermaking process of a neutral medium paper by a fourdrinier machine, an attempt was made to prevent pitch disturbance. FIG. 1 is a side view showing a part of a press part of the paper machine. The wet paper web 1 is squeezed by the roll 2 and the felt 3, and is transported while removing moisture. The roll is provided with a water doctor 4 for scraping off the deposits on the roll. Pulp slurry used for papermaking is SS
0.7% by weight, pH 7.2, zeta potential -12.2 mV. Water added to water doctor, polyvinyl imidazoline (pH
Cation degree measured at 4, 7.6, molecular weight 150,0
00) was added in an amount of 0.01 g per kg of pulp fiber. After the papermaking was continued for 24 hours, no deposit on the roll was observed. Comparative Example 1 Pitch hindrance prevention was attempted in the same manner as in Example 1 except that dicyandiamide-formaldehyde condensate (cationicity 6.0 measured at pH 4, molecular weight 50,000) was used instead of polyvinylimidazoline. After the papermaking was continued for 24 hours, the amount of deposits on the roll was slightly large. Comparative Example 2 Instead of adding polyvinyl imidazoline to the water added with the water doctor, the same procedure as in Example 1 was carried out except for mixing the pulp slurry with the inlet by adding the polyvinyl imidazoline to the inlet. After the papermaking was continued for 24 hours, the amount of deposits on the roll was slightly large. Comparative Example 3 A neutral neutral paper was made in the same manner as in Example 1 without adding a polymer. After continuing papermaking for 24 hours, a large amount of deposits were observed on the roll. Further, in Comparative Examples 1 to 3, when the roll deposits were collected and analyzed, aluminum was detected from all the deposits. Since aluminum is contained in the resin acid, the deposit is presumed to be a pitch containing the resin acid and the like. Table 1 shows the results of Example 1 and Comparative Examples 1 to 3.

[0009]

[Table 1]

As can be seen from the results in Table 1, Example 1 in which polyvinylimidazoline was added to the water added to the water doctor.
In the above, after the papermaking was continued for 24 hours, no deposits on the rolls were visually observed, and when the pitch control agent of the present invention was added to the washing water of the papermaking machine, an excellent pitch obstacle preventing effect was obtained with a small amount. ing. In contrast, Comparative Example 1 using a dicyandiamide-formaldehyde condensate conventionally known as a pitch control agent
In the above, since a relatively large amount of deposits are generated on the roll, it can be seen that the pitch control agent of the present invention has a better pitch obstacle prevention effect than the conventional pitch control agent. Even when the same polyvinyl imidazoline as in Example 1 was used in the same amount as in Example 1, in Comparative Example 2 in which it was added to the inlet and mixed with the pulp slurry, a relatively large amount of deposits was observed on the roll, and the water added to the water doctor was used. It can be seen that, when added to the inlet, the effect of preventing pitch disturbance is smaller than when added to the paper machine washing water.

[0011]

EFFECT OF THE INVENTION By applying the pitch control agent and the method for preventing pitch obstacles of the present invention, it is possible to effectively prevent paper stains, defects, paper breakage, and deterioration in workability due to pitch in the paper manufacturing process. Can be.

[Brief description of the drawings]

FIG. 1 is a side view showing a part of a press part of a paper machine.

[Explanation of symbols]

 1 wet paper 2 roll 3 felt 4 water doctor

Claims (2)

[Claims] 1. A pitch control agent comprising a water-soluble polymer having a vinylimidazoline unit represented by the general formula [1]. Embedded image (Wherein, R ¹ , R ² and R ³ are hydrogen or an alkyl group having 1 to 3 carbon atoms.) 2. A method for preventing pitch failure, comprising adding a water-soluble polymer having a vinylimidazoline unit represented by the general formula [1] to paper machine washing water. Embedded image (Wherein, R ¹ , R ² and R ³ are hydrogen or an alkyl group having 1 to 3 carbon atoms.)