Cooking accelerator and method for producing pulp using the same

Abstract

To provide a digestion accelerator further enhancing the efficiency of digestion, and a method for producing pulp using the digestion accelerator.SOLUTION: A digestion accelerator of the present invention comprises a specific quaternary ammonium compound, and at least one kind of amine compound selected from the group consisting of a specific primary monoamine, a specific secondary monoamine, and a specific tertiary monoamine. The mass ratio of the quaternary ammonium compound to the amine compound is 5: 1 to 10,000: 1. A method for producing pulp comprises a digestion step of adding at least one kind of main agent selected from the group consisting of an alkali-based main agent and a sulfite-based main agent, and a digestion accelerator to decompose a material containing lignocellulose, wherein the digestion accelerator is the above-mentioned digestion accelerator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cooking accelerator and a method for producing pulp using the same. [Background technology]

[0002] In the cooking step of a pulp production method, an alkaline base agent is used to convert lignocellulose-containing materials into pulp. A cooking accelerator is also used to ensure efficient cooking. For example, Patent Document 1 discloses a cooking accelerator containing a quaternary ammonium compound. Patent Document 2 discloses a cooking accelerator containing at least one of glucose and fructose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-65434 [Patent Document 2] Japanese Patent Publication No. 2020-2481 Summary of the Invention [Problem to be solved by the invention]

[0004] When the cooking accelerators disclosed in Patent Documents 1 and 2 are used, cooking can be performed more efficiently than cooking using only an alkaline base agent. However, in light of the recent rise in wood prices due to the expansion of wood demand and the need to curb deforestation due to global warming, there is a demand for further improvements in cooking efficiency in order to efficiently produce pulp.

[0005] In view of the above circumstances, the present invention aims to provide a cooking promoter that can efficiently cook lignocellulose-containing materials in the cooking process for converting lignocellulose-containing materials into pulp, and a method for producing pulp using the same. [Means for solving the problem]

[0006] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that the above-mentioned object can be achieved by a cooking accelerator comprising a specific quaternary ammonium compound and at least one amine compound selected from the group consisting of specific primary monoamines, specific secondary monoamines, and specific tertiary monoamines, and by a cooking accelerator comprising a specific quaternary ammonium compound and a sulfur-containing compound that generates sulfide ions, polysulfide ions, or hydrogen sulfide ions in the presence of the quaternary ammonium compound, and have thus completed the present invention.

[0007] In order to achieve the above object, [1] the cooking accelerator of the present invention comprises a quaternary ammonium compound represented by formula (1) and at least one amine compound selected from the group consisting of a primary monoamine represented by formula (2), a secondary monoamine represented by formula (3), and a tertiary monoamine represented by formula (4).

[0008] [ka]

[0009] In formula (1), R 1 represents an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms, R 2 represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n is a Y group, R 3 , and R 4each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m is a Y group, N represents a nitrogen atom; X p- represents a counter ion, which is an inorganic anion or an organic anion, p represents the valence of the ion, A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms, and Y is a hydrogen atom or an acyl group. n is an integer of 1 to 15, and m is an integer of 1 to 15.

[0010] [ka]

[0011] In formula (2), R 5 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 2 O) k Z group, A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and k is an integer of 1 to 6.

[0012] [ka]

[0013] In formula (3), R 6 , and R 7 are each independently an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r Z group, A3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r is an integer of 1 to 12.

[0014] [ka]

[0015] In formula (4), R 8 , and R 9 are each independently an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t Z group, A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t is an integer of 1 to 12. R 10 represents an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u Z group, A 5 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and u is an integer of 1 to 12.

[0016] [2] The mass ratio of the quaternary ammonium compound to the amine compound may be 5:1 to 10000:1.

[0017] [3] The cooking accelerator according to the present invention comprises a quaternary ammonium compound represented by formula (1) and a sulfur-containing compound that generates sulfide ions, polysulfide ions, or hydrogen sulfide ions in the presence of the quaternary ammonium compound.

[0018] [ka]

[0019] In formula (1), R 1 represents an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms, R 2 represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n is a Y group, R 3 , and R 4 each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m is a Y group, N represents a nitrogen atom; X p- represents a counter ion, which is an inorganic anion or an organic anion, p represents the valence of the ion, A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms, and Y is a hydrogen atom or an acyl group. n is an integer of 1 to 15, and m is an integer of 1 to 15.

[0020] [4] The sulfur-containing compound may be composed of at least one compound selected from the group consisting of thiosulfates, hydrogen thiosulfates, sulfites, hydrogen sulfites, disulfites, dithionites, dithionates, disulfates, peroxosulfates, peroxodisulfates, and polythionates.

[0021] [5] The mass ratio of the quaternary ammonium compound to the sulfur-containing compound may be 1:2 to 100:1.

[0022] In order to achieve the above object, [6] the method for producing pulp according to the present invention comprises a cooking step in which a material containing lignocellulose is cooked by adding at least one main agent selected from the group consisting of an alkali-based main agent and a sulfite-based main agent, and a cooking promoter, wherein the cooking promoter is the cooking promoter described in [1] or [3].

[0023] [7] The content of the digestion accelerator may be 0.001% by mass to 1.0% by mass with respect to the material containing lignocellulose. [Effects of the Invention]

[0024] According to the digestion accelerator of the present invention and the method for producing pulp using the digestion accelerator, materials containing lignocellulose can be efficiently digested. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "embodiment") will be described in detail. The following embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0026] [Embodiment 1] The cooking accelerator of the first embodiment contains a quaternary ammonium compound and at least one amine compound selected from the group consisting of primary monoamines, secondary monoamines, and tertiary monoamines. First, the quaternary ammonium compound and the amine compound will be described. Next, the cooking accelerator containing them will be described.

[0027] (Quaternary ammonium compounds) The quaternary ammonium compound contained in the cooking accelerator of the first embodiment is a compound represented by the following formula (1).

[0028] [ka]

[0029] In formula (1), N represents a nitrogen atom.

[0030] R in formula (1) 1 is an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms.

[0031] R in formula (1) 2 represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n Y group, where A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms. n represents the number of repeating units of the alkyleneoxy group and is a number from 1 to 15. Y is a hydrogen atom or an acyl group. Furthermore, the "number of repeating units of the alkyleneoxy group" means the "average number of moles of alkyleneoxy groups added." This is the same in all the following embodiments.

[0032] R in formula (1) 3 , and R 4 each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m Y group, where A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms. m represents the number of repeating units of the alkyleneoxy group and is a number of 1 to 15. Y is a hydrogen atom or an acyl group.

[0033] R in Equation (1) 2 , R 3 , and R 4 From the viewpoint of promoting digestion, it is preferable that the cellulose has the following structure: R 1 is preferably an alkyl group having 10 to 18 carbon atoms, a hydroxyalkyl group having 10 to 18 carbon atoms, an alkenyl group having 10 to 18 carbon atoms, or a hydroxyalkenyl group having 10 to 18 carbon atoms. 1 is more preferably a linear alkyl group having 10 to 16 carbon atoms, a linear hydroxyalkyl group having 10 to 16 carbon atoms, a linear alkenyl group having 10 to 16 carbon atoms, or a linear hydroxyalkenyl group having 10 to 16 carbon atoms.

[0034] R 2 is preferably an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n Y group, where A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms. n represents the number of repeating units of the alkyleneoxy group and is a number from 1 to 6. Y is a hydrogen atom or an acyl group. R 2 is more preferably a linear alkyl group having 1 to 22 carbon atoms, a linear hydroxyalkyl group having 1 to 22 carbon atoms, a linear alkenyl group having 2 to 22 carbon atoms, a linear hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n Y group, where A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms. n represents the number of repeating units of the alkyleneoxy group and is a number of 1 to 4. Y is a hydrogen atom or an acyl group.

[0035] R 3 , and R 4 are each independently preferably an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m Y group, where A 1O is an alkyleneoxy group having 2 to 4 carbon atoms. m represents the number of repeating units of the alkyleneoxy group and is a number from 1 to 6. Y is a hydrogen atom or an acyl group. R 3 , and R 4 are each independently more preferably an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m Y group, where A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms. m represents the number of repeating units of the alkyleneoxy group and is a number of 1 to 4. Y is a hydrogen atom or an acyl group.

[0036] Furthermore, R in equation (1) 2 , R 3 , and R 4 When is a hydroxyalkyl group, a hydroxyalkenyl group, or an alkyleneoxy group, it preferably has the following structure from the viewpoint of promoting digestion. R 2 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n In the case of a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and n is preferably an integer of 1 to 15. The sum is more preferably 1 to 9, and even more preferably 1 to 6.

[0037] R 3 , or R 4 are each independently a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 1 O) m In the case of a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and m is preferably an integer of 1 to 15. The sum is more preferably 1 to 9, and even more preferably 1 to 6.

[0038] R 2 and R 3 or R 4 In R 2 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n Y is a group, and R 3 or R 4 are each independently a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 1 O) m In the case of a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, n, and m is preferably an integer of 2 to 15. The sum is more preferably 2 to 9, and even more preferably 2 to 6.

[0039] R 3 , and R 4 In R 3 , and R 4 are each independently a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 1 O) m In the case of a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and m is preferably an integer of 2 to 15. The sum is more preferably 2 to 9, and even more preferably 2 to 6.

[0040] R 2 , R 3 , and R 4 In R 2 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n Y is a group, and R 3 , and R 4 are each independently a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 1 O) mIn the case of a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, n, and m is preferably an integer of 3 to 15. The sum is more preferably 3 to 9, and even more preferably 3 to 6.

[0041] X in formula (1) p- represents a counter ion. p represents the valence of the ion. p is 1 to 40, and from the viewpoints of commercialization, industrialization, and cost, is preferably 1 to 20, more preferably 1 to 3. The counter ion is not limited as long as it is an anion that can form a salt with the quaternary ammonium compound. Examples of the counter ion include (i) inorganic anions and (ii) organic anions.

[0042] (i) Examples of inorganic anions include halogen ions such as chloride ions and bromide ions, hydroxyl ions, sulfate ions, nitrate ions, phosphate ions, borate ions, sulfonate ions, hypochlorite ions, nitrite ions, phosphite ions, diphosphite ions, sulfite ions, hydrogen sulfite ions, sulfide ions, hydrogen sulfide ions, polysulfide ions, thiol ions, thiosulfate ions, and thioglycolate salts.

[0043] (ii) Examples of organic anions include i) organic carboxylate ions, ii) phosphate ester ions, iii) sulfonate ions, iv) alkyl carbonate ions, v) sulfate ester ions, and vi) anionic polymers. i) Examples of organic carboxylate ions include formate ions, acetate ions, propionate ions, gluconate ions, lactate ions, fumarate ions, maleate ions, and adipate ions. ii) Examples of phosphate ester ions include polyoxyalkylene alkyl ether phosphate ester ions, alkyl phosphate monoester ions, alkyl phosphate diester ions, alkenyl phosphate ester ions, and aryl phosphate ester ions. iii) Examples of sulfonate ions include alkylbenzene sulfonate ions and alkyl sulfonate ions. iv) Examples of alkyl carbonate ions include methyl carbonate ions and ethyl carbonate ions. v) Examples of sulfate ester ions include alkyl sulfate ester ions and polyoxyalkylene alkyl ether sulfate ester ions. vi) Examples of anionic polymers include polyacrylic acid, polymaleic acid, polyphosphoric acid, and polysulfuric acid compounds.

[0044] Among counter ions, from the viewpoint of promoting digestion, (i) inorganic anions are preferably halogen ions such as chloride ion and bromide ion, sulfate ion, nitrate ion, borate ion, and phosphate ion. (ii) organic anions are preferably alkyl phosphate monoester ions having an alkyl group with 1 to 4 carbon atoms such as butyl phosphate ion; alkyl phosphate diester ions having an alkyl group with 1 to 4 carbon atoms such as dibutyl phosphate ion; alkylbenzenesulfonate ions having 1 to 4 carbon atoms such as p-toluenesulfonic acid; methyl sulfate ion (CH3SO4 - ), ethyl sulfate ion (C2H5SO4 - Alkyl sulfate ester ions having an alkyl group with 1 to 4 carbon atoms, such as those of

[0045] (amine compounds) The amine compound contained in the digestion accelerator of the first embodiment is composed of at least one amine compound selected from the group consisting of primary monoamines, secondary monoamines, and tertiary monoamines.

[0046] (primary monoamine) The primary monoamine is a compound represented by the following formula (2).

[0047] [ka]

[0048] In formula (2), R 5 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 2 O) k Z group. Here, A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and k is an integer of 1 to 6.

[0049] From the viewpoint of promoting cooking, R 5 is preferably an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a hydroxyalkyl group having 1 to 18 carbon atoms, a hydroxyalkenyl group having 2 to 18 carbon atoms, or (A 2 O) k Z group. Here, A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and k is an integer of 1 or 2. R 5 is more preferably an alkyl group having 10 to 14 carbon atoms, an alkenyl group having 10 to 14 carbon atoms, a hydroxyalkyl group having 10 to 14 carbon atoms, a hydroxyalkenyl group having 10 to 14 carbon atoms, or (A 2 O) k Z group. Here, A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and k is 1.

[0050] (Secondary monoamine) The secondary monoamine is a compound represented by the following formula (3).

[0051] [ka]

[0052] In formula (3), R 6 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r1 Z group. Here, A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r1 is an integer of 1 to 12. In formula (3), R 7 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r2 Z group. Here, A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r2 is an integer of 1 to 12. 8 , and R 9 may be the same as or different from each other. where R 6 , and R 7 are respectively (A 3 O) r If Z is a group, R is used to distinguish them. 6 (A 3 O) r The Z group (A 3 O) r1 Z group and R 7 (A 3 O) r The Z group (A 3 O) r2 This is referred to as the Z group.

[0053] R in Equation (3) 6 , and R7 From the viewpoint of promoting digestion, it is preferable that the cellulose has the following structure: R 6 is preferably an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a hydroxyalkyl group having 1 to 18 carbon atoms, a hydroxyalkenyl group having 2 to 18 carbon atoms, or (A 3 O) r1 Z group. Here, A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, and Z is a hydrogen atom or an acyl group. r1 is an integer of 1 to 6. R 6 is more preferably an alkyl group having 10 to 14 carbon atoms, an alkenyl group having 10 to 14 carbon atoms, a hydroxyalkyl group having 10 to 14 carbon atoms, a hydroxyalkenyl group having 10 to 14 carbon atoms, or (A 3 O) r1 Z group. Here, A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r1 is an integer of 2 to 4.

[0054] R 7 is preferably an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a hydroxyalkyl group having 1 to 18 carbon atoms, a hydroxyalkenyl group having 2 to 18 carbon atoms, or (A 3 O) r2 Z group. Here, A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r2 is an integer of 1 to 6. 7 is more preferably an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 carbon atom, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 3 O) r2 Z group. Here, A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r2 is an integer of 2 to 4.

[0055] Furthermore, R in equation (3) 6 , and R 7When is a hydroxyalkyl group, a hydroxyalkenyl group, or an alkyleneoxy group, it preferably has the following structure from the viewpoint of promoting digestion. R 6 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r1 When it is a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and r1 is an integer of 1 to 12. The sum is preferably 1 to 6, and more preferably 1 to 4.

[0056] R 7 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r2 When it is a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and r2 is an integer of 1 to 12. The sum is preferably 1 to 6, and more preferably 1 to 4.

[0057] R 6 , and R 7 In R 6 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r1 Y is a group, and R 7 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r2 In the case of a Y group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, r1, and r2 is an integer of 2 to 12. The sum is preferably 2 to 6, and more preferably 2 to 4. In addition, R 6 , and R 7 may be the same as or different from each other.

[0058] (Tertiary monoamine) The tertiary monoamine is a compound represented by the following formula (4).

[0059] [ka]

[0060] In formula (4), R 8 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t1 Z group. A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t1 is an integer of 1 to 12. In formula (4), R 9 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t2 Z group. A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t2 is an integer of 1 to 12. 8 , and R 9 may be the same as or different from each other. where R 8 , and R 9 are respectively (A 4 O) t If Z is a group, R is used to distinguish them. 8 (A 4 O) t The Z group (A 4 O) t1 Z group and R 9 (A 4 O) t The Z group (A 4 O) t2 This is referred to as the Z group. In formula (4), R 10 represents an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u Z group. A 5O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and u is an integer of 1 to 12.

[0061] R in equation (4) 8 , R 9 and R 10 From the viewpoint of promoting digestion, it is preferable that the cellulose has the following structure: R 8 is preferably an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a hydroxyalkyl group having 1 to 18 carbon atoms, a hydroxyalkenyl group having 2 to 18 carbon atoms, or (A 4 O) t1 Z group. A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, and Z is a hydrogen atom or an acyl group. t1 is an integer of 1 to 6. R 8 is more preferably an alkyl group having 10 to 14 carbon atoms, an alkenyl group having 10 to 14 carbon atoms, a hydroxyalkyl group having 10 to 14 carbon atoms, a hydroxyalkenyl group having 10 to 14 carbon atoms, or (A 4 O) t1 Z group. A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t1 is an integer of 1 to 4.

[0062] R 9 is preferably an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, a hydroxyalkyl group having 1 to 18 carbon atoms, a hydroxyalkenyl group having 2 to 18 carbon atoms, or (A 4 O) t2 Z group. A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t2 is an integer of 1 to 6. R 9 is more preferably an alkyl group having 10 to 14 carbon atoms, an alkenyl group having 10 to 14 carbon atoms, a hydroxyalkyl group having 10 to 14 carbon atoms, a hydroxyalkenyl group having 10 to 14 carbon atoms, or (A 4 O) t2 Z group. A 4O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t2 is an integer of 1 to 4.

[0063] R 10 is preferably an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u Z group. A 5 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and u is an integer of 1 to 6. R 10 is more preferably an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u Z group. A 5 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and u is an integer of 1 to 4.

[0064] Furthermore, R in equation (4) 8 , R 9 , and R 10 When is a hydroxyalkyl group, a hydroxyalkenyl group, or an alkyleneoxy group, it preferably has the following structure from the viewpoint of promoting digestion. R 8 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t1 In the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and t1 is an integer of 1 to 12. The sum is preferably 1 to 6, and more preferably 1 to 4.

[0065] R 9 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t2In the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and t2 is an integer of 1 to 12. The sum is preferably 1 to 6, and more preferably 1 to 4.

[0066] R 10 is a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u In the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, and u is an integer of 1 to 12. The sum is preferably 1 to 6, and more preferably 1 to 4.

[0067] R 8 , and R 9 In R 8 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t1 Z group, and R 9 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t2 In the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, t1, and t2 is an integer of 2 to 12. The sum is preferably 2 to 6, and more preferably 2 to 4. In addition, R 8 , and R 9 may be the same as or different from each other.

[0068] R 8 , and R 10 In R 8 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t1 Z group, and R 10 is a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) uIn the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, t1, and u is an integer of 2 to 12. The sum is preferably 2 to 6, and more preferably 2 to 4. In addition, R 8 , and R 10 may be the same as or different from each other.

[0069] R 9 , and R 10 In R 9 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t2 Z group, and R 10 is a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u In the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, t2, and u is an integer of 2 to 12. The sum is preferably 2 to 6, and more preferably 2 to 4. In addition, R 9 , and R 10 may be the same as or different from each other.

[0070] R 8 , R 9 , and R 10 In R 8 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t1 Z group, and R 9 is a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t2 Z group, and R 10 is a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) uIn the case of a Z group, the sum of the number of hydroxyalkyl groups, the number of hydroxyalkenyl groups, t1, t2, and u is an integer of 3 to 12. The sum is preferably 3 to 6, and more preferably 3 to 4. In addition, R 8 , R 9 , and R 10 may be the same as or different from each other.

[0071] The above-mentioned amine compound is preferably a secondary monoamine, more preferably a primary monoamine, and even more preferably a tertiary monoamine, from the viewpoint of promoting digestion.

[0072] (digestion accelerator) The digestion accelerator of the first embodiment contains the above-mentioned quaternary ammonium compound and amine compound. The mass ratio of the quaternary ammonium compound to the amine compound is 5:1 to 10,000:1. From the viewpoint of accelerating digestion, this mass ratio is preferably 10:1 to 10,000:1, and more preferably 10:1 to 1,000:1.

[0073] The content of the digestion accelerator in the first embodiment is 0.001% by mass to 1.0% by mass relative to the lignocellulose-containing material. For example, the content of the digestion accelerator in the first embodiment is 1.0 to 1000 mg relative to 100 g of the lignocellulose-containing material, and from the viewpoint of promoting digestion, is preferably 2 to 500 mg, and more preferably 5 to 200 mg.

[0074] The digestion accelerator of the first embodiment may contain two or more quaternary ammonium compounds having different structures, or may contain two or more amine compounds.

[0075] By using the cooking promoter of embodiment 1, which contains the specific quaternary ammonium compound and the specific amine compound described above, in the cooking process, the activity of the quaternary ammonium compound is not lost, and materials containing lignocellulose can be efficiently cooked.

[0076] Next, a cooking accelerator according to a second embodiment will be described. [Embodiment 2] The cooking accelerator of the second embodiment contains a quaternary ammonium compound and a sulfur-containing compound that generates sulfide ions, polysulfide ions, or hydrogen sulfide ions in the presence of the quaternary ammonium compound. First, the quaternary ammonium compound and the sulfur-containing compound will be described. Next, the cooking accelerator containing these compounds will be described.

[0077] (Quaternary ammonium compounds) The quaternary ammonium compound contained in the cooking accelerator of the second embodiment is substantially the same as the quaternary ammonium compound described in the first embodiment.

[0078] (sulfur-containing compounds) The sulfur-containing compound is a compound that generates sulfide ions, polysulfide ions, or hydrogen sulfide ions in the presence of a quaternary ammonium compound. This sulfur-containing compound is composed of, for example, at least one compound selected from the group consisting of thiosulfate, hydrogen thiosulfate, sulfite, hydrogen sulfite, disulfite, dithionite, dithionate, disulfate, peroxosulfate, peroxodisulfate, and polythionate. From the viewpoint of promoting digestion, this sulfur-containing compound is preferably composed of at least one compound selected from the group consisting of sodium thiosulfate, ammonium thiosulfate, sodium hydrogen sulfide, and sodium sulfide.

[0079] (digestion accelerator) The cooking accelerator of the second embodiment contains the above-mentioned quaternary ammonium compound and sulfur-containing compound. The mass ratio of the quaternary ammonium compound to the sulfur-containing compound is 1:1 to 100:1. From the viewpoint of promoting cooking, this mass ratio is preferably 1:1 to 50:1, and more preferably 1:1 to 20:1.

[0080] The content of the digestion accelerator in the second embodiment is 0.001% by mass to 1.0% by mass relative to the lignocellulose-containing material. For example, the content of the digestion accelerator in the second embodiment is 1.0 to 1000 mg relative to 100 g of the lignocellulose-containing material, and from the viewpoint of promoting digestion, is preferably 2 to 500 mg, and more preferably 5 to 200 mg.

[0081] The cooking accelerator of the second embodiment may contain two or more quaternary ammonium compounds with different structures, or may contain two or more sulfur-containing compounds.

[0082] By using the cooking accelerator of the second embodiment, which contains the specific quaternary ammonium compound and the specific sulfur-containing compound described above, in the cooking process, lignocellulose-containing materials can be efficiently cooked. In other words, the sulfur-containing compound in the cooking accelerator creates a state in which sulfide ions, polysulfide ions, hydrogen sulfide ions, and the like are abundant around the quaternary ammonium compound. Adding this cooking accelerator to the cooking process allows lignocellulose to be cooked through an irreversible reaction. For example, in the cooking process using the alkaline cooking method, sodium sulfide or the like is added separately from the cooking accelerator. However, the sulfide ions, polysulfide ions, hydrogen sulfide ions, and the like generated by this addition are not abundant around the quaternary ammonium compound, making it difficult for an irreversible reaction to occur. This makes it difficult to efficiently cook lignocellulose.

[0083] [Solvents and additives that can be added to the first and second embodiments] The cooking accelerators of the first and second embodiments described above may contain water or an organic solvent. The cooking accelerators can be used, for example, by dissolving or emulsifying them in water or an organic solvent. Examples of organic solvents include lower alcohols with a carbon chain length of 1 to 6, such as methanol, ethanol, and propanol; alkylene glycols with a carbon chain length of 1 to 6, such as ethylene glycol, diethylene glycol, and propylene glycol; and 3-methyl-3-methoxybutanol.

[0084] The digestion accelerators of the first and second embodiments described above may further contain additives. (additives) To efficiently penetrate the cooking accelerator into the lignocellulose-containing material, additives such as nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, mineral oil, natural oils such as orange oil, alkalis, acids, etc. may be added. To improve the washability of the pulp, additives such as antifoaming agents, detergents, etc. may be added within a range that does not impair the effect of the cooking accelerator.

[0085] The alkaline agent may be an inorganic alkali, such as sodium hydroxide, potassium hydroxide, sodium carbonate, or ammonia.

[0086] Examples of the acid include inorganic acids such as hydrochloric acid, nitric acid, and phosphoric acid, and organic acids such as acetic acid, formic acid, lactic acid, and oxalic acid.

[0087] The above is a description of the compounds contained in the cooking accelerators of Embodiments 1 and 2. Next, a method for producing the quaternary ammonium compound contained in the cooking accelerators of Embodiments 1 and 2, and a method for producing the amine compound of Embodiment 1 will be described. (Method for producing quaternary ammonium compounds) The quaternary ammonium compounds of the first and second embodiments can be synthesized by various methods. 1 , R 2 , and R 3 to a tertiary amine having R 4 and reacting at a temperature of 70 to 150°C.

[0088] Another synthesis example is R 4 For quaternary ammonium compounds where R is an (AO)H group, 1 , R 2 , and R 3A tertiary amine having the formula (I) is neutralized with any acid, and then an equivalent amount of alkylene oxide is added to the neutralized mixture to carry out a quaternization reaction at a temperature of 70 to 120°C, thereby obtaining a quaternary ammonium compound. Here, AO is an alkyleneoxy group.

[0089] Another synthesis example is R 2 , R 3 , and R 4 (AO) n H group, (AO) m1 H group, and (AO) m2 In the case of a quaternary ammonium compound having a substituent represented by an H group, a predetermined amount of alkylene oxide is added to trialkanolamine and added at a temperature of 100 to 150°C. 1 A quaternary ammonium compound can be obtained by adding a quaternizing agent having the formula: and reacting at a temperature of 60 to 130° C. n, m1, and m2 are integers of 1 to 9, for example.

[0090] The amine compound contained in the cooking accelerator of embodiment 1 and the sulfur-containing compound contained in the cooking accelerator of embodiment 2 can be synthesized by known methods. For example, a tertiary monoamine can be obtained by polymerizing an alkylamine having 1 to 22 carbon atoms with an alkylene oxide at a temperature of 70 to 150°C.

[0091] (Pulp manufacturing method) The cooking accelerators of the first and second embodiments described above are used in the cooking step of a pulp manufacturing method. Next, a pulp manufacturing method using these cooking accelerators will be described. The pulp is produced by a method including a cooking process in which a material containing lignocellulose is cooked using at least one main agent selected from the group consisting of an alkali-based main agent and a sulfite-based main agent, and a cooking accelerator; a washing process in which the pulp obtained by cooking is washed; a screening process in which dust is removed from the pulp; and a bleaching process in which the pulp is bleached.

[0092] In the cooking process, for example, the cooking promoter of the embodiment, a material containing lignocellulose, and an alkaline base agent are added to a digester, and the mixture is cooked under high temperature and high pressure conditions. Fiber (pulp) is extracted from the lignocellulose by this cooking.

[0093] The temperature, pressure, and time in the cooking step are appropriately set depending on the type, shape, and size of the lignocellulose-containing material. For example, when the lignocellulose-containing material is wood chips, the temperature is, for example, 50 to 300°C, and preferably 80 to 250°C from the viewpoint of reducing the load on equipment such as a digester. The pressure is, for example, atmospheric pressure to 10 MPa, and preferably atmospheric pressure to 5 MPa from the viewpoint of reducing the load on equipment such as a digester. The cooking time is, for example, 1 to 5 hours from the viewpoint of reducing the load on equipment such as a digester.

[0094] Examples of cooking methods used in this cooking step include alkaline cooking and sulfite cooking. Alkaline cooking can be further divided into Kraft, soda, sodium carbonate, and polysulfide cooking. Sulfite cooking can be further divided into alkaline sulfite, neutral sulfite, and bisulfite cooking. From the viewpoint of accelerating cooking, alkaline cooking is preferred. Among alkaline cooking methods, Kraft and polysulfide are preferred.

[0095] Examples of alkaline base agents used in alkaline cooking include sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate. The amount of alkaline base agent added in the cooking step varies depending on the type of lignocellulose-containing material, but is generally 1 to 120 parts by mass per 100 parts by mass of lignocellulose-containing material. From the viewpoints of efficiently cooking and exerting the effects of the cooking accelerator, the amount is preferably 3 to 60 parts by mass, and more preferably 5 to 60 parts by mass.

[0096] The Kraft process, which is one of the alkaline cooking methods, involves cooking by adding an alkaline base agent and sodium sulfide. For example, when the alkaline base agent is sodium hydroxide, the amount of sodium sulfide added is 1 to 200 parts by mass, and preferably 10 to 100 parts by mass, per 100 parts by mass of sodium hydroxide, from the viewpoint of efficient cooking.

[0097] The polysulfide method, which is one type of alkaline cooking method, involves adding an alkaline base agent, sodium sulfide, and sodium polysulfide (Na2Sx, x = 2 to 5) to cook the pulp. For example, when the alkaline base agent is sodium hydroxide, the amount of sodium sulfide added is 1 to 200 parts by mass per 100 parts by mass of sodium hydroxide, and from the viewpoint of efficient cooking, it is preferably 10 to 100 parts by mass. The amount of sodium polysulfide added is 1 to 200 parts by mass per 100 parts by mass of sodium hydroxide, and from the viewpoint of efficient cooking, it is preferably 10 to 100 parts by mass.

[0098] The soda process, one of the alkaline cooking methods, involves adding an alkaline base, such as sodium hydroxide.

[0099] Examples of materials containing lignocellulose include wood, plants, etc. Examples of wood include L-lumber made from broad-leaved trees and N-lumber made from coniferous trees. Examples of plants include bacus, reed, kenaf, mulberry, bamboo, etc. Wood and plants are used, for example, in the form of chips. [Example]

[0100] The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples. In the examples and comparative examples, the following quaternary ammonium compounds, amine compounds, sulfur-containing compounds, and lignocellulose-containing materials were used.

[0101] (Quaternary ammonium compounds) R of the quaternary ammonium compounds (E1 to E8, e9 to e10) used in the examples and comparative examples 1 , R 2 , R 3 , R 4 、 The counter ions have the structures shown in Table 1. The quaternary ammonium compounds (E1 to E8, e9 to e10) were synthesized.

[0102] [Table 1]

[0103] (Synthesis of Quaternary Ammonium Compound E1) One molar equivalent of lauryldimethylamine was added to a four-neck flask equipped with a reflux condenser and heated to 85 to 95° C. 1.1 molar equivalents of diethyl sulfate was added dropwise to the mixture while stirring to carry out a quaternization reaction, thereby obtaining quaternary ammonium compound E1.

[0104] (Synthesis of Quaternary Ammonium Compound E2) One molar equivalent of lauryldimethylamine and twice the mass of distilled water relative to the mass of lauryldimethylamine were added to a four-neck flask equipped with a reflux condenser and heated to 85 to 95° C. 1.1 molar equivalents of benzyl chloride were added dropwise to the mixture while stirring to carry out a quaternization reaction, yielding E2.

[0105] (Synthesis of Quaternary Ammonium Compound E3) One molar equivalent of laurylamine was added to a pressure-resistant reactor, and after purging with nitrogen, the vessel was heated to 120-130°C. Two molar equivalents of ethylene oxide were then blown into the vessel, yielding an adduct in which two molar equivalents of ethylene oxide were added to laurylamine. Next, one molar equivalent of the resulting adduct was added to a four-neck flask equipped with a reflux condenser and heated to 85-95°C. 1.1 molar equivalents of diethyl sulfate were added dropwise to the vessel while stirring, causing a quaternization reaction to yield quaternary ammonium compound E3.

[0106] (Synthesis of Quaternary Ammonium Compound E4) One molar equivalent of laurylamine was added to a pressure-resistant reactor, which was then purged with nitrogen and heated to 120-130°C. Two molar equivalents of ethylene oxide were then blown into the reactor to obtain an adduct in which two molar equivalents of ethylene oxide were added to laurylamine. Next, distilled water was added in an amount twice the mass of the resulting adduct, and one molar equivalent of nitric acid was added for neutralization. The mixture was then heated to 85-95°C, and 1.1 molar equivalents of ethylene oxide were blown in to induce a quaternization reaction. Finally, the mixture was dehydrated under reduced pressure in an evaporator at 70°C to obtain quaternary ammonium compound E4.

[0107] (Synthesis of Quaternary Ammonium Compound E5) One molar equivalent of stearyldimethylamine was added to a four-neck flask equipped with a reflux condenser and heated to 85 to 95° C. 1.1 molar equivalents of dimethyl sulfate was added dropwise to the mixture while stirring to carry out a quaternization reaction, thereby obtaining quaternary ammonium compound E5.

[0108] (Synthesis of Quaternary Ammonium Compound E6) One molar equivalent of octyldimethylamine was added to a pressure-resistant reactor, followed by distilled water in an amount twice the mass of the octylamine, and then 0.7 molar equivalents of phosphoric acid. The mixture was then heated to 85-95°C, and 1.1 molar equivalents of ethylene oxide was blown in to cause a quaternization reaction, yielding the quaternary ammonium compound E6.

[0109] (Synthesis of Quaternary Ammonium Compound E7) One molar equivalent of laurylamine was added to a pressure-resistant reactor, which was then purged with nitrogen and heated to 120-130°C. Eight molar equivalents of ethylene oxide were then blown into the reactor to obtain an adduct in which 8 molar equivalents of ethylene oxide were added to laurylamine. Next, distilled water was added in an amount twice the mass of the resulting adduct, and 1.0 molar equivalent of paratoluenesulfonic acid was added for neutralization. The mixture was then heated to 85-95°C, and 1.1 molar equivalents of ethylene oxide were blown in to carry out a quaternization reaction, yielding quaternary ammonium compound E7.

[0110] (Quaternary ammonium compounds E8) Didecyldimethylammonium chloride (Tokyo Chemical Industry Co., Ltd.) was used.

[0111] (Synthesis of quaternary ammonium compound e9) One molar equivalent of laurylamine was added to a pressure-resistant reactor, and after purging with nitrogen, the vessel was heated to 120-130°C. 32 molar equivalents of ethylene oxide were then blown into the vessel, yielding an adduct in which 32 molar equivalents of ethylene oxide had been added to laurylamine. One molar equivalent of the resulting adduct was added to a four-neck flask equipped with a reflux condenser, and the mixture was heated to 85-95°C. 1.1 molar equivalents of dimethyl sulfate were added dropwise to the vessel while stirring, causing a quaternization reaction, yielding quaternary ammonium compound E9.

[0112] (Synthesis of quaternary ammonium compound e10) One molar equivalent of hexylamine was added to a pressure-resistant reactor, and after purging with nitrogen, the vessel was heated to 120-130°C. Two molar equivalents of ethylene oxide were then blown into the vessel, yielding an adduct in which two molar equivalents of ethylene oxide were added to laurylamine. Next, one molar equivalent of the resulting adduct was added to a four-neck flask equipped with a reflux condenser and heated to 85-95°C. 1.1 molar equivalents of diethyl sulfate were added dropwise to the vessel while stirring, causing a quaternization reaction to yield quaternary ammonium compound E10.

[0113] (amine compounds) The following amine compounds were used: A1 tetradecylamine was used as the primary monoamine. As the secondary monoamine, A2 diethanolamine was used. As tertiary monoamines, A3 N,N-dimethyldecylamine, A4 N-lauryldiethanolamine, and A5 triethanolamine were used. These amine compounds used were manufactured by Tokyo Chemical Industry Co., Ltd.

[0114] Tertiary monoamines a6 and a7 were synthesized as follows. (Synthesis of tertiary monoamine a6) One molar equivalent of laurylamine was added to a pressure-resistant reaction vessel, and after purging with nitrogen, the vessel was heated to 120 to 130° C. 30 molar equivalents of ethylene oxide were blown into the vessel to obtain an adduct a6 in which 30 molar equivalents of ethylene oxide were added to laurylamine.

[0115] (Synthesis of tertiary monoamine a7) One molar equivalent of laurylamine was added to a pressure-resistant reaction vessel, and after purging with nitrogen, the vessel was heated to 120 to 130° C. 50 molar equivalents of ethylene oxide were blown into the vessel to obtain an adduct a7 in which 50 molar equivalents of ethylene oxide were added to laurylamine.

[0116] (sulfur-containing compounds) The sulfur-containing compounds used were B1 sodium thiosulfate, B2 ammonium thiosulfate, B3 sodium hydrogen sulfide, B4 sodium sulfide, B5 sodium sulfide, B6 potassium sulfite, B7 sodium hydrogen sulfite, and b8 sodium sulfate. The sulfur-containing compounds B1 to B4, B6 to B7, and b8 were manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The sulfur-containing compound B5 was manufactured by Nagao Corporation.

[0117] (lignocellulose-containing materials) Wood chips were used as the lignocellulose-containing material. L-wood: Wood chips made from hardwood (acacia:eucalyptus = 7:3), N wood: Wood chips made from coniferous trees (red pine).

[0118] Various evaluations were carried out using the above-mentioned quaternary ammonium compounds, amine compounds, sulfur-containing compounds, and materials containing lignocellulose.

[0119] (Example 1, L-wood, Kraft process, digestion accelerator containing an amine compound) Kraft cooking was performed using L-lumber as wood chips and a cooking accelerator containing a quaternary ammonium compound and an amine compound. First, the L-lumber was passed through a 710 μm mesh stainless steel sieve, and the L-lumber remaining on the sieve was dried at 60 °C for 24 hours. The cooking accelerator was prepared so that the content of quaternary ammonium compound E4 (pure content) and amine compound A1 (pure content) relative to the L-lumber (wood chips) was 0.03 mass% and the mass ratio of quaternary ammonium compound E4 (pure content) to amine compound A1 (pure content) was 100:1. Specifically, 14.85 mg of quaternary ammonium compound E4 (pure content) and 0.15 mg of amine compound A1 (pure content) were placed in a container with 50.0 g of L-lumber (wood chips) and dissolved in distilled water to obtain the cooking accelerator used in Example 1. Next, 6.9 g of sodium sulfide pentahydrate (3.2 g of pure sodium sulfide) and 11.2 g of sodium hydroxide were added to a beaker, and distilled water was added to bring the total mass to 145 g to obtain an alkaline aqueous solution. The previously prepared cooking accelerator was added to this aqueous solution, and distilled water was added to bring the total mass to 150 g, followed by stirring to obtain a cooking liquor. 50.0 g of the prepared L-lumber and 150 g of cooking liquor were placed in a pot (MINI COLOR, manufactured by Texam Giken Co., Ltd.) and cooked at 150°C for 50 minutes.

[0120] After cooking, the wood chip residual rate, yield rate, and kappa number for Example 1 were evaluated, and the results are shown in Table 2. The wood chip residual rate, yield rate, and kappa number were evaluated by the following procedures. <Wood fragment residual rate (wood chip residual rate)> By examining the wood fragment residual rate (wood chip residual rate), it is possible to determine the degree to which the wood fragments (wood chips) have been digested. The wood fragment residual rate is also called the wood chip residual rate.

[0121] The wood chip residual rate was calculated using the following formula. Wood chip residual rate (%) = (mass of residue after cooking (g) / mass of sample before cooking (g)) x 100 Here, the residue after cooking was determined as follows: First, the mixture obtained by cooking was sieved. Next, the residue remaining on a stainless steel sieve with 710 μm mesh was washed with water, and washing was repeated until the washing water became colorless. Then, it was dried at 105°C for 10 hours. This was determined as the residue. The sample before cooking refers to wood chips that were sieved and dried before cooking. For example, in the case of Example 1, it was L-shaped wood that was sieved and dried before cooking.

[0122] The evaluation criteria for the wood chip residual rate when using the Kraft method and L-shaped wood are as follows: Excellent: wood fragment residue rate is less than 0.5% Good: Wood fragment residual rate is 0.5% or more and less than 1.5%. Poor: Wood fragment residual rate is 1.5% or more and less than 2.5%. Bad: The residual rate of wood fragments is 2.5% or more.

[0123] <Yield rate> The retention rate is the retention rate of the pulp obtained after cooking, and was calculated using the following formula. Yield rate (%) = (((i) mass of recovered pulp (g) + (ii) mass of remaining wood chips (g) × 1 / 2) / (iii) mass of sample before cooking (g)) × 100 (i) The mass of recovered pulp was the mass of pulp obtained after the following treatments. First, the mixture obtained by cooking was passed through a stainless steel sieve with a mesh size of 710 μm, and the mixture that passed through that sieve was passed through a finer stainless steel sieve with a mesh size of 75 μm. The residue remaining on the sieve was washed with water, and washing was repeated until the washing water became colorless. This residue was then dried at 105°C for 10 hours. The mass was then measured, and this was taken as the mass of recovered pulp. (ii) The mass of the wood chip residue was taken as the mass of the residue obtained after the following treatment. First, the residue remaining on a stainless steel sieve with 710 μm mesh size from the mixture obtained by cooking was washed with water, and washing was repeated until the washing water became colorless. It was then dried at 105°C for 10 hours. The mass was then measured and taken as the mass of the wood chip residue. Here, assuming that the residue after cooking would be cooked again, the mass obtained by multiplying the mass of the residue obtained after the treatment (mass of the wood chip residue) by 1 / 2 was considered to be the mass of pulp that could be further recovered, and this was added to the numerator in the formula. (iii) The pre-cooked sample is wood chips that have been sieved and dried before cooking. For example, in the case of Example 1, it is L-wood that has been sieved and dried before cooking.

[0124] The evaluation criteria for yield rate when using the Kraft method and L-shaped material are as follows: Excellent: Yield rate is 52.5% or more, Good: Yield rate is less than 52.5%, 52.0% or more, Poor: Yield rate is less than 52.0%, 51.5% or more, Bad: Yield rate is less than 51.5%.

[0125] <Kappa number> The kappa number indicates the residual lignin content. The kappa number of the pulp obtained after cooking is low due to the low residual lignin content. Furthermore, by examining the kappa number of the pulp obtained after cooking, the degree of cooking of the wood pieces (wood chips) can be determined. The following process was performed to obtain the cooked pulp. First, the mixture obtained by cooking was passed through a stainless steel sieve with a mesh size of 710 μm. The mixture that passed through this sieve was then passed through a finer stainless steel sieve with a mesh size of 75 μm. The residue remaining on the sieve was washed with water and repeated washing until the washing water became colorless. The residue was then dried at 105°C for 10 hours. This was used as the pulp. The kappa number was determined according to the method described in JIS P 8211 (2011).

[0126] The evaluation criteria for the kappa number when using L-shaped wood using the Kraft method are as follows: Excellent: Kappa number less than 15.5, Good: Kappa number is 15.5 or more and less than 16.0. Poor: Kappa number is 16.0 or more, but less than 16.5. Bad: Kappa number is 16.5 or higher.

[0127] (Examples 2 to 17, Comparative Examples 1 to 17, L-type wood, Kraft method, digestion accelerator containing an amine compound) In Examples 2 to 17 and Comparative Examples 1 to 17, cooking was carried out and evaluated in the same manner as in Example 1, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and the amine compound were changed as shown in Tables 2 and 3. In Comparative Example 1, cooking was carried out and evaluated without adding a cooking accelerator.

[0128] [Table 2]

[0129] [Table 3]

[0130] (Example 18, N wood, Kraft process, digestion accelerator containing amine compound) Kraft cooking was carried out using N-wood as wood chips and a cooking accelerator containing a quaternary ammonium compound and an amine compound. In Example 18, the quaternary ammonium compound was E1, the amine compound was A4, the wood chips were N material, and cooking was performed and evaluated in essentially the same manner as in Example 1, except that the amounts of sodium sulfide pentahydrate and sodium hydroxide added were changed. In Example 18, 7.75 g of sodium sulfide pentahydrate (3.6 g as pure sodium sulfide alone) and 12.6 g of sodium hydroxide were added to the cooking liquor. The evaluation criteria for the Kraft method and N wood were as follows: (1) Evaluation criteria for wood fragment residual rate Excellent: wood fragment residue rate is less than 0.5% Good: Wood fragment residual rate is 0.5% or more and less than 1.5%. Poor: Wood fragment residual rate is 1.5% or more and less than 2.5%. Bad: The residual rate of wood fragments is 2.5% or more. (2) Yield rate evaluation criteria Excellent: Yield rate is 52.5% or more, Good: Yield rate is less than 52.5%, 52.0% or more, Poor: Yield rate is less than 52.0%, 51.5% or more, Bad: Yield rate is less than 51.5%. (3) Kappa number evaluation criteria Excellent: Kappa number less than 29.0, Good: Kappa number is 29.0 or more and less than 29.5. Poor: Kappa number is 29.5 or more and less than 30.0. Bad: Kappa number is 30.0 or higher.

[0131] (Examples 19 to 22, Comparative Examples 18 to 26, N wood, Kraft method, digestion accelerator containing an amine compound) Examples 19 to 22 and Comparative Examples 18 to 26 were cooked and evaluated in the same manner as in Example 18, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and amine compound were changed as shown in Tables 4 and 5. Note that Comparative Example 18 was cooked and evaluated without adding a cooking accelerator.

[0132] [Table 4]

[0133] [Table 5]

[0134] (Example 23, N material, polysulfide method, digestion accelerator containing amine compound) The wood chips were N-wood and the cooking accelerator containing quaternary ammonium compounds and amine compounds was used for cooking by the polysulfide method. In Example 23, the quaternary ammonium compound was E1, the amine compound was A4, the wood chips were N material, the amounts of sodium sulfide pentahydrate and sodium hydroxide added were varied, and sodium tetrasulfide solution (manufactured by Nagao Co., Ltd.) was newly added, and cooking and evaluation were carried out in essentially the same manner as in Example 1. In Example 23, 6.2 g of sodium sulfide pentahydrate (2.88 g in terms of pure sodium sulfide), 12.6 g of sodium hydroxide, and 2.4 g of sodium tetrasulfide solution (0.72 g in terms of pure sodium tetrasulfide) were added to the cooking liquor. The evaluation criteria for the polysulfide method and N material were as follows: (1) Evaluation criteria for wood fragment residual rate Excellent: wood fragment residue rate is less than 0.5% Good: Wood fragment residual rate is 0.5% or more and less than 1.5%. Poor: Wood fragment residual rate is 1.5% or more and less than 2.5%. Bad: The residual rate of wood fragments is 2.5% or more. (2) Yield rate evaluation criteria Excellent: Yield rate is 52.5% or more, Good: Yield rate is less than 52.5%, 52.0% or more, Poor: Yield rate is less than 52.0%, 51.5% or more, Bad: Yield rate is less than 51.5%. (3) Kappa number evaluation criteria Excellent: Kappa number less than 29.0, Good: Kappa number is 29.0 or more and less than 29.5. Poor: Kappa number is 29.5 or more and less than 30.0. Bad: Kappa number is 30.0 or higher.

[0135] (Examples 24 and 25, Comparative Examples 27 to 31, N material, polysulfide method, digestion accelerator containing an amine compound) Examples 24 and 25 and Comparative Examples 27 to 31 were cooked and evaluated in the same manner as in Example 23, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and amine compound were changed as shown in Tables 6 and 7. Note that Comparative Example 27 was cooked and evaluated without adding a cooking accelerator. Each evaluation was performed according to the same evaluation criteria as in Example 23.

[0136] [Table 6]

[0137] [Table 7]

[0138] (Example 26, L wood, soda process, digestion accelerator containing amine compound) The wood chips were L-wood and the cooking accelerator containing a quaternary ammonium compound and an amine compound was used for the soda cooking. In Example 26, the quaternary ammonium compound E1, the amine compound A4, and the wood chips were used as L-lumber. Only sodium hydroxide was used as the alkaline base, with the amount of sodium hydroxide added varied. The L-lumber (wood chips) was prepared so that the content of the quaternary ammonium compound E1 (pure content) and the amine compound A4 (pure content) was 0.06% by mass, and the mass ratio of the quaternary ammonium compound E1 (pure content) to the amine compound A4 (pure content) was 100:1. Specifically, 29.7 mg of the quaternary ammonium compound E1 (pure content) and 0.3 mg of the amine compound A4 (pure content) were placed in a container and dissolved in water for 50.0 g of L-lumber (wood chips) to obtain the cooking accelerator used in Example 26. Except for this, cooking was performed and evaluated using essentially the same procedure as in Example 1. In Example 26, 16.2 g of sodium hydroxide was added to the cooking liquor. The evaluation criteria for the soda method and L material were as follows: (1) Evaluation criteria for wood fragment residual rate Excellent: wood fragment residue rate is less than 1.0% Good: Wood fragment residual rate is 1.0% or more and less than 1.5%. Poor: Wood fragment residual rate is 1.5% or more and less than 2.5%. Bad: The residual rate of wood fragments is 2.5% or more. (2) Yield rate evaluation criteria Excellent: Yield rate is 52.0% or more, Good: Yield rate is less than 52.0%, 51.5% or more, Poor: Yield rate is less than 51.5%, 51.0% or more, Bad: Yield rate is less than 51.0%. (3) Kappa number evaluation criteria Excellent: Kappa number less than 18.5, Good: Kappa number is 18.5 or more and less than 19.0. Poor: Kappa number is 19.0 or more, but less than 19.5. Bad: Kappa number is 19.5 or higher.

[0139] (Examples 27 and 28, Comparative Examples 32 to 36, L material, soda method, digestion accelerator containing an amine compound) Examples 27 and 28 and Comparative Examples 32 to 36 were cooked in the same manner as in Example 26, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and the amine compound were changed as shown in Tables 8 and 9, and were evaluated using the same evaluation criteria as in Example 26. Note that Comparative Example 32 was cooked and evaluated without adding a cooking accelerator.

[0140] [Table 8]

[0141] [Table 9]

[0142] Example 29, L-wood, Kraft process, digestion accelerator containing sulfur-containing compound Kraft cooking was performed using L-lumber as wood chips and a cooking accelerator containing a quaternary ammonium compound and a sulfur-containing compound. The L-lumber was passed through a 710 μm mesh stainless steel sieve, and the L-lumber remaining on the sieve was dried at 60 °C for 24 hours. The cooking accelerator was prepared so that the content of quaternary ammonium compound E3 (pure content) and sulfur-containing compound B1 (pure content) relative to the L-lumber (wood chips) was 0.03 mass% and the mass ratio of quaternary ammonium compound E3 (pure content) to sulfur-containing compound B1 (pure content) was 6:1. Specifically, 12.86 mg of quaternary ammonium compound E3 (pure content) and 2.14 mg of sulfur-containing compound B1 (pure content) were placed in a container with 50.0 g of L-lumber (wood chips) and dissolved in distilled water to obtain the cooking accelerator used in Example 29. Next, 6.9 g of sodium sulfide pentahydrate (3.2 g of pure sodium sulfide) and 11.2 g of sodium hydroxide were added to a beaker, and distilled water was added to bring the total mass to 145 g to obtain an alkaline aqueous solution. The previously prepared cooking accelerator was added to this aqueous solution, and distilled water was added to bring the total mass to 150 g, followed by stirring to obtain a cooking liquor. 50.0 g of the prepared L-lumber and 150 g of cooking liquor were placed in a pot (MINI COLOR, manufactured by Texam Giken Co., Ltd.) and cooked at 150°C for 50 minutes.

[0143] After cooking, Example 29 was evaluated for wood chip residual rate, yield rate, and kappa number, and the results are shown in Table 10. The wood chip residual rate, yield rate, and kappa number of Example 29 were evaluated using the same evaluation criteria as those of Example 1.

[0144] (Examples 30 to 44, Comparative Examples 37 to 44, L-wood, Kraft process, cooking accelerator containing sulfur-containing compound) In Examples 30 to 44 and Comparative Examples 37 to 44, cooking was carried out and evaluated in the same manner as in Example 29, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and sulfur-containing compound were changed as shown in Tables 10 and 11. In Comparative Example 44, the quaternary ammonium compound and the sulfur-containing compound were added separately. Only 12.86 mg of quaternary ammonium compound E3 (pure content) was placed in a container and dissolved in distilled water to obtain the cooking accelerator used in Comparative Example 44. Next, 2.14 mg of sulfur-containing compound B1 (pure content), which was not added during the preparation of the cooking accelerator, 6.9 g of sodium sulfide pentahydrate (3.2 g as pure content of sodium sulfide alone), and 11.2 g of sodium hydroxide were added to a beaker, and distilled water was added to make a total mass of 145 g to obtain an alkaline aqueous solution. The previously prepared cooking accelerator was then added to this aqueous solution, and distilled water was added to make a total mass of 150 g. The mixture was stirred to obtain a cooking liquor. Then, 50.0 g of L-type wood and 150 g of cooking liquor were placed in a pot (MINI COLOR, manufactured by Texam Giken Co., Ltd.) and cooked at 150 °C for 50 minutes. As described above, Comparative Example 44 differs from Example 29 in that the sulfur-containing compound B1 (pure content) was not added when preparing the cooking accelerator, but was added when preparing the cooking liquor. The evaluation criteria were the same as those of Example 29, and were the same as those of Example 1.

[0145] [Table 10]

[0146] [Table 11]

[0147] Example 45, N wood, Kraft process, digestion accelerator containing sulfur-containing compound Kraft cooking was carried out using N-wood as wood chips and a cooking accelerator containing a quaternary ammonium compound and a sulfur-containing compound. In Example 45, cooking was carried out and evaluated using essentially the same procedures as in Example 18, except that the quaternary ammonium compound was E2, the sulfur-containing compound was B1, the wood chips were N material, and the amounts of sodium sulfide pentahydrate and sodium hydroxide added were changed. In Example 45, 7.75 g of sodium sulfide pentahydrate (3.6 g as pure sodium sulfide alone) and 12.6 g of sodium hydroxide were added to the cooking liquor. The wood chip residual rate, yield rate, and kappa number in Example 45 were evaluated using the same evaluation criteria as in Example 18.

[0148] (Examples 46 to 49, Comparative Examples 45 to 50, N wood, Kraft process, cooking accelerator containing sulfur-containing compound) In Examples 46 to 49 and Comparative Examples 45 to 50, cooking was carried out in the same manner as in Example 45, and the results were evaluated using the same criteria, except that the types, amounts, and mass ratios of the quaternary ammonium compound and the sulfur-containing compound were changed, as shown in Tables 12 and 13. In Comparative Example 50, the quaternary ammonium compound and the sulfur-containing compound were added separately. This example differs from Example 46 in that the sulfur-containing compound B2 (pure content) was not added when preparing the cooking accelerator, but was added when preparing the cooking liquor.

[0149] [Table 12]

[0150] [Table 13]

[0151] (Example 50, N material, polysulfide method, cooking accelerator containing sulfur-containing compound) The wood chips were N-wood and the cooking accelerator containing quaternary ammonium compounds and sulfur-containing compounds was used for cooking by the polysulfide method. Example 50 was evaluated by cooking essentially in the same manner as Example 23, except that the quaternary ammonium compound was E2, the sulfur-containing compound was B3, the wood chips were N material, the amounts of sodium sulfide pentahydrate and sodium hydroxide added were varied, and sodium tetrasulfide solution (manufactured by Nagao Co., Ltd.) was newly added. In Example 50, 6.2 g of sodium sulfide pentahydrate (2.88 g in terms of pure sodium sulfide), 12.6 g of sodium hydroxide, and 2.4 g of sodium tetrasulfide solution (0.72 g in terms of pure sodium tetrasulfide) were added to the cooking liquor. The wood chip residual rate, yield, and kappa number of Example 50 were evaluated using the same evaluation criteria as Example 23.

[0152] (Examples 51 and 52, Comparative Examples 51 to 55, N material, polysulfide method, cooking accelerator containing sulfur-containing compound) Examples 51 and 52 and Comparative Examples 51 to 55 were cooked and evaluated in the same manner as in Example 50, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and sulfur-containing compound were changed as shown in Tables 14 and 15. The wood chip residual rate, yield rate, and kappa number were evaluated using the same evaluation criteria as in Example 23. In Comparative Example 55, the quaternary ammonium compound and the sulfur-containing compound were added separately. Only 12.86 mg of quaternary ammonium compound E4 (pure content) was placed in a container and dissolved with distilled water to obtain the cooking accelerator used in Comparative Example 55. Next, 2.14 mg of the sulfur-containing compound B1 (pure content), which was not added during the preparation of the cooking accelerator, 6.2 g of sodium sulfide pentahydrate (2.88 g in terms of pure content of sodium sulfide alone), 12.6 g of sodium hydroxide, and 2.4 g of sodium tetrasulfide solution (0.72 g in terms of pure content of sodium tetrasulfide alone) were added to a beaker, and distilled water was added to make the total mass 145 g to obtain an alkaline aqueous solution. The previously prepared cooking accelerator was then added to this aqueous solution, and distilled water was added to make the total mass 150 g, followed by stirring to obtain a cooking liquor. Then, 50.0 g of N wood and 150 g of cooking liquor were placed in a pot (MINI COLOR, manufactured by Texam Giken Co., Ltd.) and cooked at 150°C for 50 minutes. As described above, Comparative Example 55 differs from Example 51 in that the sulfur-containing compound B1 (pure content) was not added when preparing the cooking accelerator, but was added when preparing the cooking liquor.

[0153] [Table 14]

[0154] [Table 15]

[0155] (Example 53, L-wood, soda process, cooking accelerator containing sulfur-containing compound) The wood chips were L-wood and the cooking accelerators contained quaternary ammonium compounds and sulfur-containing compounds. In Example 53, the quaternary ammonium compound E2, the sulfur-containing compound B4, and the wood chips were L-lumber. Only sodium hydroxide was used as the alkaline base, with varying amounts added. The L-lumber (wood chips) was prepared so that the content of the quaternary ammonium compound E2 (pure) and the sulfur-containing compound B4 (pure) was 0.06% by mass, and the mass ratio of the quaternary ammonium compound E2 (pure) to the sulfur-containing compound B4 (pure) was 6:1. Specifically, 25.71 mg of the quaternary ammonium compound E2 (pure) and 4.29 mg of the sulfur-containing compound B4 (pure) were placed in a container and dissolved in distilled water for 50.0 g of L-lumber (wood chips) to obtain the cooking accelerator used in Example 53. Except for this, cooking was performed and evaluated using essentially the same procedure as in Example 26. 16.2 g of sodium hydroxide was added to the cooking liquor. The wood chip residual rate, yield rate, and kappa number were evaluated according to the same evaluation criteria as in Example 26.

[0156] (Examples 54 and 55, Comparative Examples 56 to 61, L-wood, soda process, cooking accelerator containing sulfur-containing compound) In Examples 54 and 55 and Comparative Examples 56 to 61, cooking was performed and evaluated in the same manner as in Example 53, except that the types, amounts used, and mass ratios of the quaternary ammonium compound and sulfur-containing compound were changed as shown in Tables 16 and 17. In Comparative Example 61, the quaternary ammonium compound and sulfur-containing compound were added separately. This example differs from Example 54 in that the sulfur-containing compound B2 (pure content) was not added when preparing the cooking accelerator, but was added when preparing the cooking liquor. The wood chip residual rate, yield rate, and kappa number were evaluated using the same evaluation criteria as in Example 26.

[0157] [Table 16]

[0158] [Table 17]

[0159] The cooking accelerators of Examples 1 to 55 were found to have good wood chip residual rates, yield rates, and kappa numbers in cooking by the Kraft method, cooking by the polysulfide method, and cooking by the soda method.

[0160] As described above, the cooking accelerator of the present invention can more efficiently cook materials containing lignocellulose.

[0161] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to illustrate the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0162] (Addendum) (Appendix 1) A quaternary ammonium compound represented by formula (1), A cooking accelerator comprising at least one amine compound selected from the group consisting of a primary monoamine represented by formula (2), a secondary monoamine represented by formula (3), and a tertiary monoamine represented by formula (4). [ka] In formula (1), R 1 represents an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms, R 2 represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n is a Y group, R 3 , and R 4 each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m is a Y group, N represents a nitrogen atom; X p- represents a counter ion, which is an inorganic anion or an organic anion, p represents the valence of the ion, A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms, and Y is a hydrogen atom or an acyl group. n is an integer of 1 to 9, and m is an integer of 1 to 9. [ka] In formula (2), R 5 represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 2 O) kZ group, and A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and k is an integer of 1 to 6. [ka] In formula (3), R 6 , and R 7 are each independently an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 3 O) r Z group, and A 3 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r is an integer of 1 to 12. [ka] In formula (4), R 8 , and R 9 are each independently an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 4 O) t Z group, and A 4 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, t is an integer of 1 to 12, and R 10 represents an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A 5 O) u Z group, and A 5 O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and u is an integer of 1 to 12.

[0163] (Appendix 2) 2. The cooking accelerator according to claim 1, wherein the mass ratio of the quaternary ammonium compound to the amine compound is 5:1 to 10000:1.

[0164] (Appendix 3) A quaternary ammonium compound represented by formula (1), a sulfur-containing compound that generates sulfide ions, polysulfide ions, or hydrogen sulfide ions in the presence of the quaternary ammonium compound. [ka] In formula (1), R 1 represents an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms, R 2 represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A 1 O) n is a Y group, R 3 , and R 4 each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A 1 O) m is a Y group, N represents a nitrogen atom; X p- represents a counter ion, which is an inorganic anion or an organic anion, p represents the valence of the ion, A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms, and Y is a hydrogen atom or an acyl group. n is an integer of 1 to 15, and m is an integer of 1 to 15.

[0165] (Appendix 4) 4. The cooking accelerator according to claim 3, wherein the sulfur-containing compound is at least one compound selected from the group consisting of thiosulfates, hydrogen thiosulfates, sulfites, bisulfites, disulfites, dithionites, dithionates, disulfates, peroxosulfates, peroxodisulfates, and polythionates.

[0166] (Appendix 5) 5. The cooking accelerator according to claim 3 or 4, wherein the mass ratio of the quaternary ammonium compound to the sulfur-containing compound is 1:2 to 100:1.

[0167] (Appendix 6) A method for producing pulp, comprising a cooking step of cooking a material containing lignocellulose by adding at least one main agent selected from the group consisting of an alkali-based main agent and a sulfite-based main agent, and a cooking accelerator, A method for producing pulp, wherein the cooking accelerator is the cooking accelerator described in any one of Appendix 1 to Appendix 5.

[0168] (Appendix 7) 7. The method for producing pulp according to claim 6, wherein the content of the cooking accelerator is 0.001% by mass to 1.0% by mass with respect to the material containing lignocellulose.

Claims

1. a quaternary ammonium compound represented by formula (1); A cooking accelerator comprising at least one amine compound selected from the group consisting of a primary monoamine represented by formula (2), a secondary monoamine represented by formula (3), and a tertiary monoamine represented by formula (4). 【Chemistry 1】 In formula (1), R １ represents an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms, R ２ represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A １ O) ｎ is a Y group, R ３ , and R ４ each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A １ O) ｍ is a Y group, N represents a nitrogen atom; X ｐ－ represents a counter ion, which is an inorganic anion or an organic anion, p represents the valence of the ion, A １ O is an alkyleneoxy group having 2 to 4 carbon atoms, Y is a hydrogen atom or an acyl group, n is an integer from 1 to 15, and m is an integer from 1 to 15. 【Chemistry 2】 In formula (2), R ５ represents an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A ２ O) ｋ Z group, and A ２ O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and k is an integer of 1 to 6. 【Transformation 3】 In formula (3), R ６ , and R ７ are each independently an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A ３ O) ｒ Z group, and A ３ O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and r is an integer of 1 to 12. 【Chemistry 4】 In formula (4), R ８ , and R ９ are each independently an alkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A ４ O) ｔ Z group, and A ４ O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and t is an integer of 1 to 12. R １０ represents an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, or (A ５ O) ｕ Z group, and A ５ O is an alkyleneoxy group having 2 to 4 carbon atoms, Z is a hydrogen atom or an acyl group, and u is an integer of 1 to 12.

2. 2. The cooking accelerator according to claim 1, wherein the mass ratio of the quaternary ammonium compound to the amine compound is 5:1 to 10,000:

1.

3. a quaternary ammonium compound represented by formula (1); a sulfur-containing compound that generates sulfide ions, polysulfide ions, or hydrogen sulfide ions in the presence of the quaternary ammonium compound. 【Transformation 5】 In formula (1), R １ represents an alkyl group having 8 to 22 carbon atoms, a hydroxyalkyl group having 8 to 22 carbon atoms, an alkenyl group having 8 to 22 carbon atoms, or a hydroxyalkenyl group having 8 to 22 carbon atoms, R ２ represents an alkyl group having 1 to 22 carbon atoms, a hydroxyalkyl group having 1 to 22 carbon atoms, an alkenyl group having 2 to 22 carbon atoms, a hydroxyalkenyl group having 2 to 22 carbon atoms, or (A １ O) ｎ is a Y group, R ３ , and R ４ each independently represents an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a hydroxyalkenyl group having 2 to 4 carbon atoms, an aryl group, a benzyl group which may have an alkyl group having 1 to 4 carbon atoms, a phenethyl group which may have an alkyl group having 1 to 4 carbon atoms, a glycidyl group, or (A １ O) ｍ is a Y group, N represents a nitrogen atom; X ｐ－ represents a counter ion, which is an inorganic anion or an organic anion, p represents the valence of the ion, A １ O is an alkyleneoxy group having 2 to 4 carbon atoms, Y is a hydrogen atom or an acyl group, n is an integer from 1 to 15, and m is an integer from 1 to 15.

4. 4. The cooking accelerator of claim 3, wherein the sulfur-containing compound comprises at least one compound selected from the group consisting of thiosulfates, bisthiosulfates, sulfites, bisulfites, disulfites, dithionites, dithionates, disulfates, peroxosulfates, peroxodisulfates, and polythionates.

5. 5. The cooking accelerator according to claim 3, wherein the mass ratio of the quaternary ammonium compound to the sulfur-containing compound is 1:2 to 100:

1.

6. A method for producing pulp, comprising a cooking step of cooking a material containing lignocellulose by adding at least one main agent selected from the group consisting of an alkali-based main agent and a sulfite-based main agent, and a cooking accelerator, A method for producing pulp, wherein the cooking accelerator is the cooking accelerator according to claim 1 or 3.

7. The method for producing pulp according to claim 6, wherein the content of the cooking accelerator is 0.001% by mass to 1.0% by mass relative to the material containing lignocellulose.

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