JPH0429794B2 - - Google Patents

Abstract

A process for preparing mechanical pulp and/or paper containing the mechanical pulp is described, wherein an acylglycerol lipase is used. The process according to the invention avoids the problems caused by the resins in the preparation of mechanical pulp and/or paper containing said pulp.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is based on groundwood pulp (hereinafter referred to as GP).
The present invention relates to a method for preventing pitch troubles that occur in the manufacturing process of mechanical pulp such as (abbreviated) or in the papermaking process that uses mechanical pulp. (Prior art) Mechanical pulp such as GP is made into pulp by a simple mechanical process of grinding logs or chips with a grinder or refiner.
Although it is inferior in strength to chemical pulp that uses chemicals such as alkali, it has the advantages of high yield, low cost, and high opacity. However, on the other hand, since mechanical grinding is used as a means of pulping, the wood components remain in the pulp almost unchanged. In general, wood contains 1 to 1 to 100% of pituti component, which is an organic solvent extract, in addition to the three main components of setrose, hemicellulose, and lignin.
Contains about 10%. Pitch components vary quantitatively and qualitatively depending on the tree species, but softwood, which is the main raw material for mechanical pulp, is known to contain large amounts of pitch components such as fatty acids, resin acids, and fatty acid glycerides. During pulping, some of these pitch components separate from the pulp and become floating, or become attached to or coated on the fiber surface, and are released from the fixed state before pulping. . Pituchi is detached and floating in white water.
It is a fine particle of about 0.2 to 2 microns and is called colloidal pitch. In general, paper is produced by pulp produced in various pulping processes, passed through a sorting process, mixed with papermaking materials, and then sent to a papermaking process to become a product. During this series of processes, free floating pitches or attached pitches accumulate on the pulp, tank, wire section, roll section, etc., causing paper stains and paper breaks, resulting in so-called pitch trouble. If it is mixed with other substances, pitch trouble is likely to occur frequently. One of the typical methods that has traditionally been used to prevent pitch trouble is a process called seasoning, in which logs are felled, piled up outdoors, and left to wither over a long period of time. As another method, for example,
As described in Publication No. 22606, a method of adding polyoxyethylene alkyl ether or alkyl phenyl derivatives having various addition mole numbers or surfactants containing these as main components during pulping and paper making processes. It has been known. (Problems to be Solved by the Invention) According to the above seasoning method, the pitch component in the wood changes and decreases mainly due to air oxidation, but seasoning requires a vast area and 3 to 6 months, depending on the case. has the problem that it takes longer than that, and it is currently difficult to prevent pitch trouble by seasoning alone. On the other hand, the method of adding a surfactant is said to be effective in dispersing fine particle pitches and preventing their accumulation, but it has not been used as a fundamental method for preventing pitch troubles. The present invention aims to provide a method for preventing pitch trouble, which is still a major problem in the manufacturing process of mechanical pulp or the papermaking process using mechanical pulp. (Means for Solving the Problems) In order to find an effective means for preventing pitch trouble, the present inventors first used a pitch component extracted from Japanese red pine wood, which is a typical raw wood for mechanical pulp, and
As a result of a detailed search for the pituti components deposited in the process of manufacturing GP using red pine logs or in the paper making process using red pine GP, the main components of the deposited pitch were found to be components derived from the wood, especially triglycerides, fatty acids, and resin acids. It has become clear that there are a lot of metal salts of these, and it has also become clear that the deposited pit always contains a large amount of triglycerides. From these results, triglycerides are presumed to be one of the main causative substances of piti trouble. The present inventors have tried various chemical and biochemical methods from the viewpoint that it is effective to decompose and remove triglycerides in some way to prevent pit trouble. The present invention was completed based on the discovery that the use of a fatty acid glyceride hydrolase is optimal for decomposing triglycerides and preventing the accumulation of pits without adversely affecting the quality of pulp and paper and operating conditions. did. That is, the method for preventing pitch trouble according to the present invention is to treat papermaking raw materials and/or white water with a fatty acid glyceride hydrolyzing enzyme in a mechanical pulp manufacturing process and/or a papermaking process using mechanical pulp. or removing pitch in white water, and the enzyme is Aspergillus niger, Pseudomonas fluorescens.
fluorescens), Pseudomonas flagi (Pseudo
-monas fragi), Geotrichum candidum, or Candida candidum.
Claim 2: Use of a fatty acid glyceride hydrolase produced by one or more microorganisms selected from Candida cylindracea.
This is the characteristic of The enzyme used in the present invention is an enzyme that hydrolyzes triglyceride, which is one of the main components of pitch. Any type of fatty acid glyceride hydrolase is effective, and the microorganism that produces this enzyme is Aspergillus niger.
-llus niger), Pseudomonas fluorescens, Pseudomonas fragi, Geotrichum candideum
candidum), Candida cylindracea, Mucor javanicus, Rhizopus javanicus, Rhizopus delemar, Rhizopus niveus, Rhizopus filamentous fungi Examples 1 to 5 of the above examples can be given.
The fatty acid glyceride hydrolase produced by the microorganism described in item 3 is particularly effective. In addition, the fatty acid glyceride degrading enzyme produced by the above microorganisms is more effective as it is purified.
Multiple enzymes may be used together. Furthermore, the fatty acid glyceride degrading enzyme used in the present invention exhibits sufficient effects even when used in combination with other degrading enzymes such as cellulase, hemicellulase, and protease. In order to use these enzymes in a mechanical pulp production process or a papermaking process using mechanical pulp, the enzymes are added to a papermaking raw material slurry containing mechanical pulp obtained by grinding with a grinder or refiner. weight ratio 0.1
Add ~10000ppm and let stand or stir gently.
In this case, the temperature is suitably 10 to 70°C, most preferably 35 to 55°C. If the temperature is below 10°C, the action of the enzyme will be slow and the reaction rate will be slow, and if it is above 70°C, the enzyme may be deactivated. Generally, the larger the amount of enzyme added, the faster the reaction rate will be, but in this case, 10,000 ppm based on mechanical pulp is sufficient, calculated from the amount of triglyceride as a substrate, and adding more than that is not economically viable. It will be disadvantageous. Furthermore, a pH range of 3 to 11 is appropriate; outside this range, enzyme activity is significantly inhibited. Also, large amounts of water are used in the pulping and papermaking processes, but most of it is recycled and reused.
Since these circulating white waters contain pitch components, pitch troubles can also be prevented by applying enzymes to the circulating white waters.
In this case, the fatty acid glyceride hydrolase is directly added to white water, or the enzyme and the microorganism that produces the enzyme are immobilized by known methods such as carrier binding, crosslinking, and embedding. Excellent effects can also be obtained by using enzymes or immobilized microorganisms. The method according to the present invention causes an extremely highly selective enzymatic reaction with respect to the triglyceride to be treated, and the reaction itself is mild, so there is no deterioration of the treated papermaking raw materials and existing operations can be carried out. It does not have any adverse effects on. In addition, in the method of the present invention, anionic, nonionic, and cationic surfactants may be used together with the enzyme. (Function) The mechanism of pitch accumulation, which causes pitch trouble, is a complex system in which pulp fibers, pitch, metal ions, fillers, etc. coexist. It is thought that factors such as type are related, but it is not completely clear yet. In general, the phenomenon of adsorption onto a solid surface is caused by the Van der Waals force that fixes the adsorbate to the solid surface. There are many types of interactions between the two, but important ones include hydrophobic bonds and dipole-dipole interactions. Additionally, hydrophobic or nonpolar molecules or portions of molecules tend to be attracted to hydrophobic or nonpolar surfaces, and conversely, hydrophilic or polar molecules tend to be attracted to hydrophilic or polar surfaces. Therefore, the role played by triglycerides in the pitch accumulation mechanism in the pulping process and papermaking process is considered to be as follows. Triglyceride, which is a non-polar component in colloidal pitch, adheres to metal surfaces such as tanks and pipes, and hydrophobic or non-polar surfaces such as center rolls in paper manufacturing presses due to van der Waals forces, and this part becomes the nucleus, forming a pitch. Hydrophobic or non-polar molecules or portions of molecules in the components adhere one after another to form a pitch deposit. The mechanism for preventing pitch deposits of the present invention is that a fatty acid glyceride-degrading enzyme is used to treat non-polar fatty acid triglycerides that are highly adhesive to hydrophobic and non-polar surfaces in mechanical pulp surfaces, pitch in circulating white water, and colloidal pits. It is thought that this action inhibits deposition on hydrophobic metal pipes, tank walls, etc. by hydrolyzing it into water-soluble glycerol and fatty acids having polar groups. Therefore, since adhesion is inhibited at the initial stage of deposition, the growth of pitch deposits is inhibited and pitch troubles are prevented. (Effects of the Invention) According to the present invention, it is possible to inhibit the accumulation of pitch components in a mechanical pulp manufacturing process or a paper manufacturing process using mechanical pulp, and to prevent pitch troubles such as paper stains and paper breaks caused by accumulated pitches. I can do it. Furthermore, the method of the present invention does not have any adverse effect on product quality or actual operations, is simple, does not require any special equipment or equipment, and can be applied directly to existing pulping and papermaking processes. It is. (Example) The present invention will be described below according to Examples.
In addition, in each Example, the case where enzyme treatment was not performed was shown as a blank. Example 1 Extract 10 obtained by extracting red pine wood chips immediately after felling with methanol using a Soxhlet extractor
g was dissolved in a mixture of 100 ml of isopropanol, 60 ml of acetone and 5 ml of water. This pitch solution
10ml was added to a beaker containing 1 part of water and stirred vigorously to suspend and disperse. The resulting methanol-extracted pitch was obtained at a yield of 4.7% based on the dry chip weight, and the triglyceride content of this pitch was
It was 37.8%. Next, the prepared pitch dispersion was adjusted to pH 7 with hydrochloric acid and sodium hydroxide, and fatty acid glyceride degrading enzymes produced by various microorganisms were added at various concentrations as shown in Table 1, and the mixture was gently stirred at various temperatures for 4 hours. and reaction treatment. To measure the adhesion amount of pitch, TAPP1
According to RC-324, add hydrochloric acid band and hydrochloric acid to the above reaction treatment solution to adjust the pH to 4, and make a
A cylindrical polyethylene plate of 1.5 cm was rolled into a cylindrical shape, set so that 2.5 cm protruded from the water surface, and stirred for 30 minutes using a vibromixer (Linitator, manufactured by Haydon, USA).
Thereafter, the polyethylene plate was pulled out, dried, and the amount of adhered pitch was determined, which is shown in Table 1 along with the percentage relative to the blank.

[Table] Example 2 Using the pitch dispersion prepared in Example 1,
This dispersion was adjusted to pH 7 with hydrochloric acid and sodium hydroxide, and a fatty acid glyceride degrading enzyme was added to the solution.
500 ppm was added, and the solution was stirred gently while maintaining the temperature at 40°C. After a predetermined period of time had elapsed, the amount of adhesion pitches was determined in the same manner as in Example 1 and is shown in Table 2.

[Table] Produced by Licum Candeideum.
Example 3 Slurry 1 containing 63ml GP10g of Canadian Standard Freeness (CSF) manufactured from red pine wood was used as a sample, and enzymes were added at various concentrations according to Example 1 and treated under various PH conditions. Measure the amount of pitch adhered to the polyethylene plate using
It is shown in Table 3.

[Table] Example 4 Using the same sample material as in Example 3, 50 ppm of enzyme was added to the pulp according to Example 1, and the mixture was heated at various temperatures.
The amount of pitch adhesion was measured for various treatment times and is shown in Table 4.

[Table] Example 5 Newspaper pulp (CSF 105ml) 20, GP (CSF
63ml) 25, Thermomechanical Pulp (CSF 107
Example 1 Using 1% pulp slurry 1 mixed at a ratio of 25 ml) and 30 kraft pulp as a sample,
Add 50ppm of enzyme to the pulp according to the temperature 40℃
After enzymatic treatment for 4 hours, a polyethylene plate was set and stirred for 120 minutes using a vibromixer, and the amount of pitch adhered was measured. The results are shown in Table 5.

[Table] Example 6 Using white water 3 obtained when pulp is filtered in the washing process after the grinding process of Akamatsu GP production as a sample, the white water 0.5 ppm was prepared according to Example 1.
After adding a concentrated amount of enzyme and performing enzyme treatment at a temperature of 40°C for 2 hours, stirring with a vibromixer for 120 minutes,
The amount of pitch adhered to the polyethylene plate was measured and shown in Table 6.
It was shown to.

[Table] Example 7 In a Verbeformer multi-tube paper machine with a paper making width of 5080 mm and a paper making speed of 830 m/min, the raw material pulp composition was
GP: Newspaper DIP: NKP: TMP = 30:45:10:15
Newspaper with a basis weight of approximately 46 g/m ² was made.
Among the raw materials mentioned above, GP is manufactured from Japanese red pine, and after being adjusted to a freeness of 60 to 70 by post-refining and temporarily stocked as finished pulp, it is mixed with other raw materials as needed and then reused. It is stocked and sent to the paper making process. After passing through the post-refiner, the retention time is approximately 90 minutes until it passes through each CHEST tank and reaches the papermaking process.
Lipase OF was carried out at a concentration of 3 ppm. Continuous addition was carried out for two weeks, and the amount of pitches adhering to the paper machine wire and press section and the frequency of scraping off the pitches adhering to the center roll were investigated. The operating output of this paper machine was approximately 270 tons per day. In addition,
The above-mentioned pitch scraping work is performed manually to prevent excessive pitch from adhering to the center roll for smooth operation, and as the amount of adhering pitch increases, the frequency of work increases. Increase. For comparison, in the case without enzyme addition,
The amount of pitch and work frequency were investigated. The results are shown in Table 7.

[Table] Example 8 According to Example 7, the raw material pulp composition was GP: newspaper DIP: NKP: TMP = 20:50:15:15,
When making lightweight printing paper with a basis weight of 34g/ ^m2 ,
Lipase OF was added at 3 ppm to the GP slurry. The operating output in this case was approximately 200 tons per day. Comparisons with the case without enzyme addition were made based on the amount of pitches adhering to the wire and press section of the paper machine, and the number of pieces of paper torn off due to pitches adhering to the breaker stack. The results are shown in Table 8.

【table】

Claims (1)

[Claims] 1. In a mechanical pulp manufacturing process and/or a paper manufacturing process using mechanical pulp, papermaking raw materials and/or white water are treated with a fatty acid glyceride hydrolase to remove pitch in the papermaking raw materials and/or white water. A method for preventing pitch trouble, which is characterized by removing it. 2 As an enzyme, Aspergillus niger, Pseudomonas fluorescens, Pseudomonas fragi, Geotrichum candidium
2. The method for preventing pitch trouble according to claim 1, characterized in that a fatty acid glyceride hydrolase produced by one or more microorganisms selected from Candidum cylindracea or Candida cylindracea is used.