JPH0120276B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing pulp, which comprises adding and cooking a dihydroxyanthracene compound and a polyalkylene oxide polymer in the cooking step of producing alkaline pulp or sulfite pulp. In the present invention, alkaline pulp refers to the Kraft method, the soda method, the soda method,
It is a general term for various alkaline-cooked pulps such as polysulfide process, and sulfite process pulp is a general term for various sulfite process pulps such as alkaline sulfite process, neutral sulfite process, and bisulfite process. When producing pulp from wood, bagasse, hemp, and other lignocellulosic materials, improving the pulping yield, increasing the cooking rate, and improving the pulp quality will reduce the wood consumption rate and energy consumption rate. This is an essential condition for economically producing high-quality products, and various attempts have been made for this purpose. For example, in JP-A No. 53-74101 ``Method for producing pulp'' (applied by Honshu Paper Industries), a small amount of hydroxyanthracene derivative is added in the pulping process in which lignocellulose material is treated with an alkaline chemical solution or a sulfite method chemical solution. A method is indicated which is characterized in that cooking is carried out. Among these, the hydroxyanthracene derivative is a water-soluble dihydroxyanthracene compound typified by dihydrodihydroxyanthracene. On the other hand, a reagent for pulp production containing a fine powder of a water-insoluble quinone compound or an organic cyclic compound containing a hydroxyl group and a surfactant was published in JP-A-55
-A water-dispersed quinone compound composition in which a water-insoluble quinone compound powder and an ionic surfactant are uniformly mixed, according to No. 6585 "Reagent for pulp production" (filed by Bayer Aktiengesellschaft). The details are disclosed in Japanese Patent Application Laid-open No. 100332/1983, "Quinone Compound Composition and Method for Producing the Same" (Nippon Steel Chemical Application). JP-A-55-6585 and JP-A-54-100332 both aim to obtain a stable aqueous quinone compound suspension by pulverizing a water-insoluble quinone compound and combining it with an activator. The idea is to disperse fine powder of a water-insoluble quinone compound in water using the action of an activator. The present invention utilizes a dihydroxyanthracene compound, which is soluble in water as is, in combination with a specific polyalkylene oxide polymer that is stable in alkaline and sulfite cooking processes, to improve dihydroxylation into lignocellulosic materials such as wood chips. Penetration and diffusion of anthracene compounds is promoted,
It has been found that the yield, cooking rate, and pulp quality are further improved than when the dihydroxyanthracene compound is added alone. Generally, for wood chips, NaOH,
Penetration of Na ₂ S, Na ₂ SO ₃ , etc. is relatively fast, but the rate of penetration and diffusion of dihydroxyanthracene compounds, which have large molecules, into the interior of wood chips is extremely slow. Therefore, for example, in the case of wood chips with low moisture content, chips with a high resin content, or when the time required for chemical solution to penetrate into the chips during the cooking process is short, adding a dihydroxyanthracene compound alone will not sufficiently penetrate and diffuse the dihydroxyanthracene compound into the interior of the wood chips. Therefore, the effect of its addition could not be fully exhibited. The present invention uses a specific nonionic or anionic polyalkylene oxide polymer that is chemically stable at the chemical solution and temperature during alkaline cooking or sulfite cooking and is used as a penetration enhancer of dihydroxyanthracene compounds into wood chips. When used in combination with an anthracene compound, the dihydroxyanthracene compound quickly penetrates into the inside of the chips, and the peeling reaction suppressing action of the dihydroxyanthracene compound prevents the noticeable decomposition and elution of hemicellulose that occurs in the early stages of cooking, resulting in an effective cooking process. The aim is to improve retention and pulp quality. The water-soluble dihydroxyanthracene compound used in the present invention is preferably 9,10-dihydroxyanthracene (anthrahydroquinone) or 1,4-dihydro-9,10-dihydroxyanthracene.
-3%, preferably 0.01-0.1%. In addition, the specific polyalkylene oxide polymers used in conjunction with this as a penetration enhancer into lignocellulosic materials include polyphenol adducts of polyoxyalkylene, especially polyethylene oxide, and various adducts of polyethylene oxide and polypropylene oxide copolymers. A nonionic or anionic surfactant that is stable at the chemical solution and temperature during alkaline cooking or sulfite cooking, and that promotes the penetration of dihydroxyanthracene compounds. It was selected because it was found to have excellent performance as a drug. Cationic compounds inhibit the cooking aid effect of dihydroxyanthracene compounds, that is, both the effects of improving cooking yield and improving cooking speed.
Nonionic and anionic surfactants that do not contain polyoxyalkylene in their hydrophilic groups are not as effective as polyalkylene oxide polymers, perhaps because they are unstable in the cooking liquor or have less penetration promoting effect. I couldn't help it. Examples of nonionic or anionic polyalkylene oxide polymers include polyhydric phenol adducts of polyethylene oxide (nonionic) or higher fatty acids, alcohols, alkylphenols, or polycyclic phenol adducts of polyethylene oxide and polypropylene oxide copolymers (nonionic); These sulfuric acid ester salts and phosphoric acid ester salts (anions) are used, and the amount thereof added is 0.001 to 1%, preferably 0.002 to 0.5%, based on the weight of the lignocellulose material, during normal cooking. For example, 9,10-dihydroxyanthracene (hereinafter abbreviated as dihydroxyanthracene) is obtained by reducing anthraquinone with hydrosulfide, and 1,4-dihydro-9,10-dihydroxyanthracene (hereinafter abbreviated as dihydrodihydroxyanthracene) is obtained by reducing anthraquinone with hydrosulfide. They can be easily obtained by reacting a Diels-Alder reaction adduct of naphthoquinone and butadiene with an acid such as dilute sulfuric acid, and these water-soluble dihydroxyanthracene compounds are easily dissolved in ordinary cooking liquors. The polyalkylene oxide polymer of the present invention used in combination with this may be dissolved simultaneously with the dihydroxyanthracene compound into the ordinary cooking liquor, or may be added directly to the chips at the inlet of the wooden pot, separately from the dihydroxyanthracene compound. good. On the other hand, quinone compounds that are insoluble in water (e.g. 9,10
Even if the polyalkylene oxide polymer of the present invention is used in combination with (anthraquinone), the quinone compound is insoluble in the cooking liquor at the early stage of cooking, so it has no effect on promoting penetration into the interior of the chips. Therefore, unlike the case of the present invention, no effect of combined use on improving yield or promoting digestion is observed. This will be explained below using examples. Example 1 600 g of softwood chips were packed into 4 autoclaves, to which was added Kraft cooking liquor with 17% active alkali and 25% sulfidity, and a polycyclic phenol adduct of dihydrodihydroxyanthracene and nonionic polyethylene oxide polypropylene oxide copolymer ( Toho Chemical FL-57G) was added at 165°C by adding 0.05% and 0.005% of the chip weight, respectively.
Cooked for 75 minutes. On the other hand, for comparison, cooking was carried out using the ordinary Kraft method and the Kraft method with the addition of only 0.05% dihydrodihydroxyanthracene. These results are shown in Table 1.

[Table] Example 2 700 g of hardwood chips were packed in a No. 4 autoclave, and a soda cooking liquor containing 15.5% NaOH (as Na ₂ O) was added thereto, followed by alcohol addition of dihydroxyanthracene and nonionic polyethylene oxide polypropylene oxide copolymer. (Toho Chemical FT-257) was added at 0.02% and 0.01%, respectively, based on the weight of the chips, and the mixture was cooked at 155°C for 75 minutes. On the other hand, for comparison, we also conducted cooking using the normal soda method and the soda method with the addition of only 0.02% dihydroxyanthracene. These results are shown in Table 2.

[Table] Example 3 400g of flax was packed into autoclave 4, cooking liquor containing 18% Na ₂ SO ₃ and 3% NaOH was added, and higher fatty acid addition of dihydrodihydroxyanthracene and nonionic polyethylene oxide polypropylene oxide copolymer was carried out. (manufactured by Toho Chemical) were added at 0.05% and 0.005%, respectively.
Cooked at 180°C for 4 hours. Separately, for comparison, a cooking test was conducted using the sodium sulfite method in which only 0.05% of dihydrodihydroxyanthracene was added and the normal sodium sulfite method. These results are shown in Table 3.

[Table] Example 4 700g of hardwood chips were packed in a No. 4 autoclave, a soda cooking solution containing 15.5% NaOH (as Na ₂ O) was added, and 1,4-dihydro-
Alcohol adduct of 9,10-dihydroxyanthracene and nonionic polyethylene oxide polypropylene oxide copolymer (manufactured by Toho Chemical)
FT257) for the absolute dry weight of the chips, respectively.
0.02% and 0.005% were added and cooked at 155°C for 75 minutes. On the other hand, for comparison, a similar experiment was conducted using 9,10-anthraquinone, which is insoluble in water. These results are shown in Table 4. The water-soluble dihydrodihydroxyanthracene of the present invention has an effect in combination with a penetrating agent, but the water-insoluble 9,10
- It turns out that anthraquinone has no effect when used in combination.

[Table] Example 5 600g of softwood chips were packed into 4 autoclaves, and kraft cooking liquor with 17% active alkali and 25% sulfidity was added, and dihydrodihydroxyanthracene and anionic polyoxyethylene tristyrylphenyl ether sulfate were added. Ammonium salt (sulfate ester salt of polyhydric phenol)
(FL-57F manufactured by Toho Chemical Co., Ltd.) at 0.03% and 0.003%, respectively.
% to weight of chips and cooked at 170°C for 75 minutes. On the other hand, for comparison, only dihydrodihydroxyanthracene was added to the ordinary Kraft method and the Kraft method.
Cooking was carried out with the addition of 0.03%. These results are shown in Table 5.

[Table] Example 6 600 g of coniferous wood was packed into 4 autoclaves, and kraft cooking liquor with 17% active alkali and 25% sulfidity was added, and potassium oleyl ether phosphate ester of dihydrodihydroxyanthracene and anionic polyoxyethylene polypropylene copolymer was added. 0.04% salt (manufactured by Toho Chemical) and
0.004% to chip weight was added and cooked at 170°C for 75 minutes. On the other hand, for comparison, only dihydrodihydroxyanthracene was added to the ordinary Kraft method and the Kraft method.
Cooking was carried out with the addition of 0.04%. These results are shown in Table 6.

[Table] Comparative Example In Example 1, instead of the alcohol adduct of polyethylene oxide polypropylene oxide copolymer used in combination with dihydrodihydroxyanthracene, a polyhydric alcohol (hydrophilic group) fatty acid (Sorbon manufactured by Toho Chemical Co., Ltd.) was used as a nonionic surfactant. (Comparative Example 1), higher alcohol sulfate salt (hydrophilic group) as anionic surfactant (FL-58A manufactured by Toho Chemical Co., Ltd.) (Comparative Example 2), anionic higher alcohol sulfosuccinate salt (hydrophilic group) (manufactured by Toho Chemical Co., Ltd.) Cooking was carried out in exactly the same manner as in Example 1, except that 0.005% of AIRROLCT-1) (Comparative Example 3) and 0.005% of each of aliphatic amine (Cachinal CB-50 manufactured by Toho Chemical Co., Ltd.) (Comparative Example 4) were added as a cationic surfactant. I did this. These results are shown in Table 6. Comparing these results with the results of Example 1 shown in Table 1, it is found that nonionic surfactants (Comparative Example 1) and anionic surfactants (Comparative Examples 2 and 3) that are not included in the scope of the present invention are , the same level as when only dihydrodihydroxyanthracene was added, and no effect was observed when using a penetration enhancer in combination. Furthermore, the cationic surfactant (Comparative Example 4) has a negative effect of reducing the effect of the cooking aid. Therefore, it is clear that the specific nonionic or anionic polyalkylene oxide polymer of the present invention acts as a penetration enhancer for lignocellulosic materials and further enhances the performance of water-soluble hydroxyanthracene compounds as a cooking aid.

【table】

Claims (1)

[Scope of Claims] 1. In the process of alkaline cooking or sulfite digestion of lignocellulosic material, a water-soluble dihydroxyanthracene compound is added to the lignocellulosic material in an amount of 0.005 to 3% as a penetration enhancer of the compound into the lignocellulosic material ( (a) Polycyclic phenol adducts of polyethylene oxide or (b) Higher fatty acids, alcohols, alkylphenols, polycyclic phenol adducts (nonionic) of polyethylene oxide and polypropylene oxide copolymers, and sulfuric esters of the above (a) and (b). salts, phosphate ester salts (anionic) to lignocellulosic materials.
A method for producing pulp, which comprises adding 0.001 to 1% and cooking. 2 The water-soluble dihydroxyanthracene compound is
The method for producing pulp according to claim 1, wherein the pulp is 1,4-dihydro-9,10-dihydroxyanthracene or 9,10-dihydroxyanthracene.