JP3254741B2 - Disintegration method of wet strength paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for disintegrating wet strength paper. More specifically, the present invention relates to a disintegration method for reusing waste paper or waste paper of wet strength paper to which a wet strength agent such as polyamide epichlorohydrin resin is added as a raw material for papermaking.

[0002]

2. Description of the Related Art In recent years, the reuse of waste paper has been increasing steadily, but in the future, the reuse of recycled paper will be promoted from the standpoint of resource saving, energy saving and pollution prevention. One of the problems in the use of wet strength paper among the waste paper raw materials is the difficulty in disintegration.

[0003] That is, polyamide epichlorohydrin resin, polyamine epichlorohydrin resin, melamine-
Wet paper strength paper whose wet paper strength has been increased by a wet paper strength enhancer such as formalin resin or urea-formalin resin has the opposite characteristic that disintegration is extremely difficult when recovering and recovering waste paper or waste paper. is there. Note that, in the present invention, defibration means that used paper or waste paper is defibrated to form a slurry (thin pulp).

Heretofore, mechanical processing has generally been performed when recovering and recovering waste paper or waste paper of wet paper strength paper. In addition, a heat treatment may be performed for the purpose of promoting disaggregation during mechanical treatment, or a chemical such as an acid such as sulfamic acid, hydrochloric acid, sulfuric acid, phosphoric acid, or aluminum sulfate, or an alkali such as sodium hydroxide or potassium hydroxide. , Sodium hypochlorite, sodium chlorite, or an oxidizing agent such as hydrogen peroxide or a combination of the above agents as appropriate,
Further, a disaggregation accelerator containing a surfactant is also used as a resin removing agent and a resin decomposing agent.

[0005]

However, of the above-mentioned methods of disintegrating broke or waste paper of wet-strength paper, which is performed only by mechanical treatment, pulp suitable for a papermaking raw material containing no undisintegrated material is used. It is very difficult to recover the wastewater, and there are problems such as an increase in the recovery cost. In addition, heat treatment or a method of disintegrating chemicals in combination with mechanical treatment is still not sufficiently satisfactory in terms of the effect of promoting disintegration, and since these chemicals are used in large amounts, they dissolve in wastewater and become environmentally harmful. New problems have also arisen, such as causing pollution problems. SUMMARY OF THE INVENTION The present invention solves these problems by dissolving a waste paper or waste paper of a wet strength paper to which a wet strength agent is added and reusing the waste paper as a raw material for papermaking. Is provided.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies on a method of easily disintegrating waste paper and waste paper of wet paper strength-enhanced paper. or in the step prior to the defibration process in combination the drug, subjected to enzyme treatment by adding an enzyme comprising at least one or more cellulase broke or waste paper wet strength paper, subsequently wet strength agent The present inventors have found that the above problem can be solved by performing a disaggregation process using a specific agent corresponding thereto, and completed the present invention.

[0007] That is , the present invention relates to a case where the wet-strength paper is a cellulase or a cellulase when the wet-strength paper contains a polyamide epichlorohydrin resin.
Enzyme treatment with a solution containing at least one of zeolites and other polysaccharide-degrading enzymes , and then performing a disintegration treatment using an agent selected from the group consisting of oxidizing agents, alkalis, and disintegration accelerators. The present invention provides a method for disintegrating paper, and in the case of wet strength paper containing melamine-formalin resin and urea-formalin resin, the paper is used as a cell.
Of cellulase and other polysaccharide-degrading enzymes
An object of the present invention is to provide a method for disintegrating wet paper strength-enhancing paper, which comprises subjecting a solution containing at least one or more enzymes to an enzymatic treatment and then performing a disintegration treatment using acids.

The enzyme-treated solution of the present invention is recovered as a filtrate in a concentration step after the enzyme treatment step, and is reused by returning the filtrate to the enzyme treatment step. Therefore, the method of the present invention can greatly reduce the amount of the above-mentioned chemical agent used in the conventional method, and can reuse the enzyme-treated solution. In addition, there are advantages such as cost reduction of chemicals and wastewater treatment. In the enzyme treatment in the present invention, cellulase may be used alone, or may be used in combination with another polysaccharide-degrading enzyme such as hemicellulase or pectinase.

As the enzymes, cellulase or a polysaccharide-degrading enzyme capable of decomposing fiber components other than cellulose, such as cellulase and hemicellulase and pectinase, may be used, and those widely distributed in the animal, plant and microbial communities can be used. . Commercially available enzymes include Meiji Cellulase TP (manufactured by Meiji Seika Co., Ltd.), Cell Riser (manufactured by Nagase Seikagaku Corporation), Cell Crust (manufactured by Novo), Cellzyme (manufactured by Novo), Sumiteam AC (manufactured by Shin Nihon Chemical) Sumiteam C (manufactured by Shin Nippon Chemical Industry Co., Ltd.) and the like, but are not limited thereto.

[0010] Cellulase is generally known as a cellulolytic enzyme, but it has only been proposed in the papermaking process to utilize cellulase as a pulp beating accelerator or a waste paper deinking agent. The present inventors are the first to use cellulase for the disintegration of waste paper or waste paper of wet-strengthened paper, which is difficult to disintegrate, and filed an application related to this in the prior application (Japanese Patent Application No. 4-1).
02325). The method of combining cellulase treatment and drug treatment of the present invention is a further improvement of the method of using cellulase of the prior application.

The enzyme treatment in the present invention is preferably carried out in a step prior to the defibration treatment step using a pulper or the defibration treatment step using a chemical. The amount of the enzyme added during the enzyme treatment is 0.05 to 10% by weight, and preferably 0.1 to 1.0% by weight, based on the weight of the absolutely dried paper or waste paper. It is generally known that the larger the amount of enzyme added, the higher the reaction rate.
More enzymes may be added, but this is disadvantageous in terms of cost.

The concentration of broke or waste paper of the wet strength paper when adding the enzyme is 1 to 20% by weight, preferably 2 to 20% by weight.
10% by weight. However, since the concentration of broke or waste paper does not significantly affect the effect of the enzyme treatment, the enzyme treatment may be performed at a concentration outside this range, but this is not desirable due to operational problems. The temperature and pH of the enzyme treatment solution may be controlled within a range in which the enzyme is not deactivated, but it is preferable to adjust the temperature and the pH of the enzyme to be used optimally. Generally, the temperature of the enzyme treatment solution is 20 to 70 ° C, preferably 40 to 60 ° C, and the pH is 3.0 to 8.0, preferably 4.0 to 6.5.

Further, the enzyme treatment time varies depending on the above-mentioned treatment conditions, but is preferably 0.5 to 10 hours.
Regarding the reuse of the enzyme-treated solution, it has been confirmed that when about 90% of the enzyme-treated solution is recovered, the enzyme-treated solution can be reused two to three times. The addition of the processing solution further increases the number of reuses.

The inventor of the present application has determined that the enzyme remaining on the waste paper or waste paper without being recovered in the enzyme treatment liquid recovery step completely stops its function by a disintegration treatment using a chemical in a pulper. As has been confirmed, this is extremely advantageous in the practice of the present invention, since it prevents the enzyme from being transferred to the pulp and papermaking steps after the enzyme treatment. The drug used in the drug treatment step after the above-mentioned enzyme treatment step includes polyamide epichlorohydrin tree.
If wet strength paper containing a fat oxidizing agent, alkalis, Oh Rui include macerating promoter, melamine - formalin
Increasing wet paper strength containing phosphorus resin and urea-formalin resin
In the case of strong paper, acids Ru and the like. These drugs may be used alone, but by using heat treatment in combination,
Disintegration is further promoted.

Examples of the oxidizing agent in the present invention include hypochlorite and chlorite, and at least one of sodium salts, potassium salts and calcium salts thereof is used. Of these, hypochlorite is preferred,
Particularly preferred is sodium hypochlorite.

Examples of the acids include hydrochloric acid, sulfuric acid, sulfamic acid, phosphoric acid, aluminum sulfate and the like. At least one of them is used, and sulfuric acid is particularly preferred. Examples of the alkalis include sodium hydroxide and potassium hydroxide, and at least one of them is used, and sodium hydroxide is particularly preferred.

As the disaggregation accelerator, those in which the above-mentioned drugs are appropriately combined or in which a surfactant is further blended are used. For example, as a commercially available disintegration accelerator, OP-3
0 (manufactured by Yasu Yushi Kogyo), Bath Perth 249 (manufactured by Shin-A), Akron (manufactured by Daito Pharmaceutical), Hyper P
(Manufactured by Daito Pharmaceutical Co., Ltd.), Melcut FLG (manufactured by Daiwa Chemical Industry Co., Ltd.), Nikka Salt RB-1 (manufactured by Nichika Chemical Industry Co., Ltd.), Sintol W (manufactured by Nissin Chemical Laboratory), Hakuace PR-80
(Manufactured by Hakuto Chemical Co., Ltd.), but are not limited thereto.

It is preferable to use different chemicals for the above-mentioned disintegration depending on the type of wet paper strength enhancer to be disintegrated. That is, as the wet paper strength enhancer contained in the wet paper strength paper, (A) polyamide epichlorohydrin resin, polyamine epichlorohydrin resin, cation-modified dialdehyde starch, etc .; and (B) melamine-formalin resin, urea-formalin resin, etc. Of these, (A) an oxidizing agent, an alkali, or a disaggregation accelerator is effective for the disintegration of a wet strength paper containing a group enhancer using an enzyme; The use of an acid for the disintegration of the wet strength paper containing the group enhancer with the enzyme has a good effect.

The disintegration conditions using these oxidizing agents, acids, alkalis and disintegration accelerators are not particularly limited, but generally the following conditions may be used. The addition amount of the oxidizing agent or the disaggregation accelerator is appropriately selected depending on the degree of wet strength of the wet strength paper, but preferably, for example, the addition amount of the oxidizing agent is the effective chlorine content as the weight of completely dried paper or waste paper. 0.01 to 10% by weight per weight, and the amount of the disintegration accelerator is 0.01 to 10% by weight based on the weight of the completely dried paper or waste paper
It is. When acids or alkalis are used, p
Although it is controlled by H, it is preferably adjusted to pH 1 to 4 in the case of acids and to pH 10 to 14 in the case of alkalis.

[0020]

The mechanism of the disintegration of the wet-strength paper of the present invention does not decompose the resin only with a chemical as in the prior art, but first, an enzyme directly acts on undisintegrated cellulose fibers to remove the resin-containing portion. It is considered that the detachment facilitates the subsequent chemical treatment.

[0021]

EFFECTS OF THE INVENTION By disintegrating broke or waste paper of wet strength paper with the method of the present invention, the amount of use of chlorine-based substances and the like is greatly reduced as compared with the case where a conventionally used chemical is used. Is possible, and compared with the case of using the enzyme alone,
The time required for the disintegration treatment can be significantly reduced, and the recovered and recycled pulp can be obtained efficiently and easily without worrying about environmental pollution such as water pollution. In addition, the method of the present invention also has the advantage of saving energy and reducing the cost of chemicals and wastewater treatment.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Further, the percentages in each of the examples are% by weight, and the time required for disintegration is determined by visually observing the time required for complete disintegration until the paper piece does not contain any undisintegrated material.

Example 1 A pulp (NBKP / LBKP = 5) obtained by beating a polyamide epichlorohydrin resin wet paper strength agent (trade name, Kaimen 557H, manufactured by Dick Hercules KK) to 450 cc of Canadian Standard Freeness.
0/50) and 0.3% (solid content ratio of pulp) to the wet paper strength-enhancing paper (basis weight 66 g / m ² ) obtained by adding about 1-2 c
It was cut into m-sided paper pieces and used for the following tests.

3 g of the test paper was immersed in 150 ml of a phosphate citrate buffer (pH 5.5), and a commercially available cellulase (trade name, Meiji Cellulase TP, manufactured by Meiji Seika Co., Ltd.) derived from Trichoderma viride. Was added to the test piece by 0.5%, and 5%
Enzyme treatment was carried out by shaking at 0 ° C. for 0.5, 1.0, 2.0 hours. Next, 3 g of a paper strip subjected to the enzyme treatment was placed in an absolute dry weight of 3 g in 1 liter of a disintegration solution to which sodium hypochlorite was added to the concentration shown in Table 1, and disintegrated at 20 ° C. using a JIS standard disintegrator. Processing was performed. Table 1 shows the time required for the disaggregation.

Comparative Example 1 A test was performed under the same conditions as in Example 1 except that the enzyme treatment with cellulase was not performed. Table 1 shows the time required for the disaggregation.

Example 2 A pulp (NBKP / LBKP =) obtained by beating a polyamide epichlorohydrin resin wet paper strength agent (trade name: Kaimen 557H, manufactured by Dick Hercules KK) to 450 cc of Canadian Standard Freeness.
50/50) and 0.6% (based on pulp solids ratio) internally added to obtain a wet strength paper (basis weight 66 g / m ² ) of about 1-2 c.
It was cut into m-sided paper pieces and used for the following tests.

3 g of this test paper strip was immersed in 150 ml of phosphate citrate buffer (pH 5.5), and a commercially available cellulase (trade name, Meiji Cellulase TP, manufactured by Meiji Seika Co., Ltd.) derived from Trichoderma viride. 0.5% or 1.% of the test piece.
After adding 0%, the mixture was shaken at 50 ° C. for 2 hours or 4 hours to carry out enzyme treatment. Next, 3 g of the enzyme-treated paper piece was put into 1 liter of a disintegrating solution to which sodium hypochlorite was added so as to have a concentration shown in Table 2 as an absolute dry weight.
Disintegration treatment was performed at 20 ° C. using a standard disintegrator. Table 2 shows the time required for the disaggregation.

Comparative Example 2 A test was performed under the same conditions as in Example 2 except that the enzyme treatment with cellulase was not performed. Table 2 shows the time required for the disaggregation.

Example 3 In the same manner as in Example 2, a wet paper strength-enhancing paper piece was obtained, and 3 g of this test paper piece was treated with 150 ml of a phosphate citrate buffer solution (pH
5.5) and trichoderma viride (Tricho)
derma viride) (commercial name, Meiji Cellulase TP, manufactured by Meiji Seika Co., Ltd.)
Was added to a test piece, and the mixture was shaken at 50 ° C. for 4 hours to perform an enzyme treatment. Next, a disintegration solution adjusted to pH 12 with sodium hydroxide or potassium hydroxide, or a disintegration solution 1 in which a disintegration accelerator (trade name: Mercut FLG, manufactured by Daiwa Chemical Industry Co., Ltd.) was added to the test piece to a concentration of 4%.
Enzyme-treated paper strips as absolute dry weight of 3 liters
g, and defibrated at 20 ° C. using a JIS standard disintegrator. Table 3 shows the time required for the disaggregation.

Comparative Example 3 A test was performed under the same conditions as in Example 3 except that the enzyme treatment with cellulase was not performed. Table 3 shows the time required for the disaggregation.

Comparative Example 4 Example 3 was repeated except that sodium hydroxide, potassium hydroxide or a disintegration accelerator was not added to the disintegration solution.
The test was performed under the same conditions as described above. Table 3 shows the time required for the disaggregation.

Example 4 Pulp obtained by beating urea-formalin resin to 450 cc of Canadian Standard Freeness (NBKP /
LBKP = 50/50) and internally added 1.8% (pulp solids ratio) to obtain a wet paper strength paper, which was cut into pieces of about 1-2 cm square and used in the following tests. 150g of 3g specimen
of Trichoderma viride (pH 5.5) in Trichoderma vir.
Ide) -derived commercially available cellulase (trade name, Meiji Cellulase TP, manufactured by Meiji Seika Co., Ltd.) was added to the test paper strip by 1.0% and shaken at 50 ° C. for 4 hours to carry out enzyme treatment. Next, 3 g of a paper piece subjected to the enzyme treatment was placed in an absolute dry weight of 3 g in 1 liter of a disintegration solution adjusted to pH 2 with sulfuric acid or hydrochloric acid, and disintegrated at 20 ° C. using a JIS standard disintegrator. Table 4 shows the time required for the disaggregation.

Comparative Example 5 A test was performed under the same conditions as in Example 4 except that the enzyme treatment with cellulase was not performed. Table 4 shows the time required for the disaggregation.

Comparative Example 6 A test was performed under the same conditions as in Example 4 except that sulfuric acid or hydrochloric acid was not added to the disaggregation solution. Table 4 shows the time required for the disaggregation.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) D21B 1/14-1/34 D21C 5/02

Claims (2)

(57) [Claims] (1) a polyamide epichlorohydrin resin;
Cellulase or cellular
Containing at least one of zeolites and other polysaccharide-degrading enzymes.
Oxidizing agents, alkalis, and
A method for disintegrating wet-strength paper, wherein the disintegration treatment is performed using an agent selected from the group consisting of disintegration accelerators . 2. Melamine-formalin resin or urine
Wet paper containing paper-formalin resin
Of cellulase and other polysaccharide-degrading enzymes
After enzyme treatment with a solution containing at least one or more
Wet paper strength characterized by performing disintegration processing using
Disintegration method of strong paper.