JPS5916037B2 - Method for preventing pitch adhesion in papermaking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pitch adhesion prevention method for preventing pitch failure in a paper manufacturing process.

Various pitch disturbances occur in the paper pulp manufacturing process.

Pitch is a resin and other sticky substances found in pulpwood that can be found throughout the papermaking process: It can clump together and contaminate tools, cause pitch spots and reduce the quality of the product.
This may adversely affect sheet formation and cause paper breakage. The substances that cause pitch vary depending on the type of pulp material.

It is the raw material for sulfide pulp; domestically produced pine wood is
The pitch content was composed of fatty acid calcium, resin acid calcium, and unsaponifiable matter, which was resolved to some extent by excessive injection of sulfuric acid. Douglas fir, which is an imported chip, has a large amount of unsaponifiable matter, and even after kraft cooking, a large proportion of pitch remains in the pulp, resulting in pitch failure. Southern woods such as lauan and rubber trees contain several times as much pitch as Douglas fir, and their ingredients are mainly made up of highly sticky polymeric unsaponifiables. It remains in the pulp and causes pitch problems that are different from conventional ones, such as difficulty in bleaching and poor weather resistance. Even after deinking treatment is applied to waste newspapers and magazines, the resin from printing ink and back glue remains as a pitch, and the resin from adhesive tapes and adhesives remains in waste cardboard, causing new pitch problems. are doing.

Medications are added to prevent pitch disorder, but
Among these methods, there are those that take the pitch out of the system and those that disperse the pitch within the system.

In the former case, it is sufficient to separate the pitch from the pulp and discharge it out of the system, but in the latter case, it is completely dispersed to prevent it from adhering to the wire or felt, and to prevent any problems even if it is mixed into the paper. It is necessary for the material to be able to hold the paper and not have a negative impact on the paper. The surfactants conventionally used make pitches hydrophilic and can be discharged from the system during the next washing process or transferred into black liquor or white water. Nonionic surfactants such as alkylphenol ethylene oxide adducts used in the bleaching process have little depitching effect on Nanpo wood. In addition, surfactants used in the deinking process, such as alkyl sulfate and polyoxyethylene alkyl ether, have excellent ability to strip and disperse printing ink, but they have poor collection ability in F20-zeta. portion leaks from the deinking process. Furthermore, when a surfactant is used in the papermaking process, the surfactant destroys hydrogen bonds between celluloses, causing adverse effects such as reducing sizing and paper strength. In addition, conventionally unused solvents such as trichloroethane and toluene dissolve pitch into white water, and although they are somewhat effective, they have the disadvantage of being dangerous and deteriorating the working environment. In addition, inorganic adsorbents have disadvantages such as abrasion of heaters and wires and clogging of felt, while sulfuric acid band is based on waste paper and has almost no depitching effect on pitch, and excessive injection of it can lower the pH of the paper surface. The drawback was that it caused corrosion. The present invention improves these conventional drawbacks, exhibits a depitching effect for various pitches, does not change paper size, paper strength, paper surface PH, etc., and prevents wear of heater blades and wires. It is an object of the present invention to provide a method for preventing pitch adhesion in paper manufacturing that does not cause the paper to cause problems or deteriorate the working environment. In the present invention, a polymer containing maleamic acid and an alkene having 5 to 10 carbon atoms as an active ingredient is added to the pulp slurry before papermaking in an amount of 0.001% by weight or more based on the pulp.
1 weight? This is a method for preventing pitch adhesion in paper manufacturing, which is characterized by adding less than

Maleamic acid is a hydrophilic structural unit in which one of the two carboxyl groups of maleic acid is converted into an acid amide type.

Furthermore, the alkene is a hydrophobic structural unit, and may be linear or branched, and preferred examples include benzene, hexene, diisobutylene, and decene. Particularly preferred are alkenes having 6 to 8 carbon atoms. Diisobutylene is a dimer obtained by catalytic polymerization of isobutylene, and includes 2,4,4-trimethyl-1-benzene, 2,4,4-trimethyl-2-benzene, 2,
Included are 3,4-trimethyl-2-benzene, 3,4,4-trimethyl-2-benzene, or mixtures thereof. The polymer used in the present invention contains these structural units, but the polymer may contain other structural units that are polymerizable with these structural units. The molar ratio of maleamic acid to alkene is 85:15 to 15:85, and is preferably around 1. The molecular weight of the polymer is 1,00
0 to 50,000 preferably 1,000 to 10,000
It is. If it is less than 1,000 or more than 50,000, the effect of preventing pitch adhesion will not be significant.

As a method for producing the above polymer, there is also a method of polymerizing maleamic acid and an alkene, but one example of a desirable method is to polymerize a polymer of maleic anhydride and an alkene (usually dissolved in toluene or benzene to form a solution). % of ammonia water and amidation according to the following formula.

In formula I, if the maleic anhydride portion of the polymer and the ammonia are equimolar, the whole becomes maleamic acid.

When the amount of ammonia is small, a portion remains as maleic acid, but in this case, it is desirable that 1/2 or more of the original maleic anhydride becomes maleamic acid. If there is a large amount of ammonia, an ammonium salt of maleamic acid is generated according to the following formula. The carboxyl group in the polymer of maleic anhydride and alkene amidated with ammonia is preferably neutralized with an alkali to make it water-soluble.

For this purpose, amidation and neutralization can be performed simultaneously by adding 2 moles or more of ammonia to 1 mole of maleic anhydride. Further, as in the examples described later, equimolar reactants may be neutralized with sodium hydroxide or the like. The above-mentioned polymer can be used by being added to the pulp slurry as it is, but it is preferable to dilute it with water and then inject it because it can be uniformly dispersed.

The amount added varies depending on the pitch content in the pulp, but the O. 01% by weight or more and less than 0.1% by weight, preferably O. 0.01% by weight or more and less than 0.1% by weight.
O. If the weight is less than 0.001 e, no pitch adhesion prevention effect is observed, and if the weight is less than 0. 1 weight? Even if the above amount is added, the effect is not significantly improved, and a size effect appears, which impairs the function of tissue paper or toilet paper, which is not preferable. The addition location may be any location where the pulp slurry is being stirred before papermaking, especially in the mixing chamber,
When added to a machine chiest, etc., it can be sufficiently stirred and mixed.

When the above-mentioned polymer is used in the above-mentioned amount, pitch can be dispersed in the pulp slurry to prevent aggregation and adhesion to wires, felts, etc.

And it does not have any negative impact on the paper product.
There is no change in size, paper strength, or paper surface pH. Moreover, it does not have a negative effect on paper making tools or the working environment. The pitch adhesion prevention method of the present invention has an adhesion prevention effect on various types of pitches, including pits made from southern wood and waste paper, for which conventional methods were not effective, and this effect also applies to pitches other than maleamic acid as a constituent unit. , or an alkene having 4 or less carbon atoms or 12 or more carbon atoms.

Alkenes with carbon numbers of 4 or less and those with carbon numbers of 12 or more can both be used in prevention methods that take pitches out of the system, but when pitches are dispersed within the system, the effect of preventing pitches from adhering is significant. and cannot be used. In particular, when using 4 or less, the dispersibility of the pitch is poor, and when using 12 or more, the foaming property is large and the quality of the paper deteriorates. There is no such problem when using it. Next, the present invention will be specifically explained using experimental examples and examples. Experimental Example 1 Pitch collected from a system in which toilet paper is made from magazine waste paper was extracted with a solvent.

0.59 of this extract was suspended in 500 ml of water, and J
．． According to the TAPPI Paper Pulp Test Method Taki 11 pulp pitch wire gauging test method, a pitch adhesion test was conducted using a pitch tester, and the chemical was evaluated based on the amount of pitch adhering to the wire. The test temperature at this time was 50℃, pH 6.7
, the organic solvent is toluene. The chemical used is a copolymer of maleamic acid and pentene, hexene, diisobutylene, and decene at a 1:1 (molar ratio) (molecular weight approximately 9,
000), in which a copolymer of maleic anhydride and an alkene is reacted with equimolar amounts of ammonia, and then neutralized with sodium hydroxide to form a sodium maleamide type polymer. The results are shown in Table 1.

In addition, as a comparative example, maleamic acid and carbon number 4 and 1
Results obtained under the same conditions for a copolymer of alkenes (2), a copolymer of maleic acid and diisobutylene, and a surfactant (polyoxyethylene nonyl phenyl ether) are also listed. In the table, MAA represents maleamic acid and MA represents maleic acid. Experimental Example Pitch collected from the system being prepared was extracted with a solvent.

Using this extract, the drug was evaluated under the same conditions as in Experimental Example 1. The results are shown in Table 2. Example 1 In a machine that makes paper using waste corrugated paper as raw material, the amount of pitch in the pulp slurry was as high as 1.2% (based on the pulp), and the pitch was attached to wire and felt, hindering productivity. .

Therefore, the conjugate of maleamic acid and diisobutylene used in Experimental Examples 1 and 2 was added to the machine
．． When 03% by weight (based on pulp) was added, the amount of pitch adhesion decreased, and the number of times the felt was washed increased from 3 times/day to 0.5%.
Times/fields decreased. As a result, the amount of cleaning agent used is reduced by 1/6.
production increased by 20%. Example 2 In a machine that makes paper using kraft pulp made from softwood, pitches adhered to the pressure roll and 1
Paper ran out 3 times a day.

In this system, maleamic acid and diisobutylene copolymer are added to the machine cheese by 0.018 weight? (For pulp) When added, the amount of pitch adhesion was drastically reduced, and the number of paper breaks due to pitch was 1 time/U3. It decreased by 1. As a result, paper production increased by 30%. From the above results, it can be seen that the method for preventing pitch adhesion of the present invention is much more effective than the comparative example, and can also practically solve problems caused by pitch adhesion. Experimental Example 3 Waste paper (colored, imitation) was made into a 3% by weight pulp slurry through the processes of cooking, deinking, and bleaching, and the copolymer of maleamic acid and diisobutylene used in Experimental Examples 1 and 2 was added to this. After adding JIS method P
A handmade sheet (equivalent to toilet paper) with a basis weight of approximately 209/I was created based on JIS method P8l4 based on 82O9.
The water absorption was measured using a Klemm water absorption tester based on 1.

The results are shown in Table 3. From Table 3, is the amount added 0.1 weight?
If it is less than 1.0 weight, it will not affect the water absorption.
It can be seen that the water absorption rate decreases and a size effect appears, making it unsuitable for first-class toilet paper. Experimental example
4 Waste newspapers are digested, deinked, and bleached to produce a weight of 3?
After making a pulp slurry and adding the copolymer of maleamic acid and diisobutylene used in Experimental Examples 1 and 2, a handmade sheet (equivalent to printing paper) with a basis weight of approximately 609/I based on JIS method P82O9 was prepared. ) and JIS method P8
The Steckicht size degree was measured based on No. 122.

The results are shown in Table 4. 1. does not affect the degree of
It can be seen that at 0% by weight, a size effect appears.

As explained above, the pitch adhesion prevention method of the present invention has an adhesion prevention effect on various pitches in the paper manufacturing process, and is highly effective and has no adverse effects on products or other products.

Claims (1)

[Scope of Claims] 1. A polymer containing maleamic acid and an alkene having 5 to 10 carbon atoms as an active ingredient is added to the pulp slurry before papermaking in an amount of 0.001% by weight or more based on the pulp.
．． A method for preventing pitch adhesion in paper manufacturing, characterized by adding less than 1% by weight. 2 Alkenes include pentene, hexene, diisobutylene,
The method for preventing pitch adhesion in paper manufacturing according to claim 1, wherein the pitch adhesion prevention method is one or more selected from decene. 3 The molar ratio of maleamic acid and alkene is 85:15
15:85. The method for preventing pitch adhesion in paper manufacturing according to claim 1 or 2. 4. The method for preventing pitch adhesion in paper manufacturing according to any one of claims 1 to 3, wherein the polymer has a molecular weight of 1,000 to 50,000.