Papermaking softener, paper, and paper manufacturing method

Abstract

To provide a softener for papermaking which can simultaneously impart high flexibility and high water absorbency while maintaining the strength of paper, and can suppresses the generation of odor.SOLUTION: A softener for papermaking includes: a polyoxyalkylene hardened castor oil as a component A; a quaternary cationic surfactant containing an imidazoline ring as a component B; and a polyether polyol (excluding the component A) as a component C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a paper softener, paper, and a method for producing paper. [Background technology]

[0002] In recent years, high flexibility and water absorption have become essential for household paper products such as tissue paper, toilet paper, and towel paper. Furthermore, fabric softeners with low odor are also required, as even the slightest odor can be unpleasant for tissue paper, which is used in the nose.

[0003] Conventionally, softeners for papermaking generally known include nonionic surfactant-based softeners (e.g., Patent Document 1), cationic surfactant-based softeners (e.g., Patent Documents 2 and 3), and polyhydric alcohol-based softening and moisturizing agents.

[0004] However, although nonionic surfactant-based softeners improve water absorption, they lack flexibility. Furthermore, when added to pulp slurry before papermaking, they have poor adhesion to the pulp, so large amounts must be added to obtain paper with the desired performance, which is problematic from the perspective of production costs. Furthermore, polyoxyalkylene adducts such as castor oil and oleyl alcohol, which have unsaturated alkyl groups, have an odor specific to the raw materials, which can be unpleasant in some cases.

[0005] Cationic surfactant-based softeners have excellent fixation to pulp, but they have the problem of tending to reduce paper strength and water absorption.Furthermore, cationic surfactants produce unreacted amines and by-products during synthesis, which can cause a foul odor in the paper.

[0006] Polyhydric alcohols such as glycerin and sorbitol require a large amount to exhibit flexibility, and although they improve moisture retention, they do not improve water absorption. As a method for solving these problems, a softener that uses a nonionic surfactant having an alkyl group in combination with a cationic surfactant (Patent Document 4) is known.

[0007] Meanwhile, a tissue paper treatment agent for improving texture has been disclosed that contains one or more compounds selected from the group consisting of alkylene oxide adducts of lanolin and alkylene oxide adducts of castor oil, a polyhydric alcohol, and a surfactant (Patent Document 5). In Patent Document 5, the treatment method is coating, and the amount of coating is 50% by mass of the paper (tissue paper).

[0008] Also, a paper softener containing at least one of polyoxyalkylene castor oil and polyoxyalkylene hydrogenated castor oil, both of which contain at least propylene oxide units, and a quaternary cationic surfactant has been disclosed (Patent Document 6). While the above technology improves texture and softness, it does not take odor into consideration.

[0009] Furthermore, an unscented fabric softener composition containing a quaternary ammonium salt, alcohol, and a fragrance has been disclosed (Patent Document 7). However, depending on the type of quaternary ammonium salt, the unscentedness may not be sufficient. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Special Publication No. 41-9801 [Patent Document 2] Japanese Patent Publication No. 48-22701 [Patent Document 3] Japanese Patent Publication No. 165597 / 1983 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-44058 [Patent Document 5] Japanese Patent Application Laid-Open No. 2007-2402 [Patent Document 6] International Publication No. 2019 / 146698 [Patent Document 7] Japanese Patent Publication No. 2020-122246 Summary of the Invention [Problem to be solved by the invention]

[0011] Under these circumstances, the main object of the present invention is to provide a paper softener that can simultaneously impart high flexibility and high water absorbency to paper while maintaining its strength, and that suppresses the generation of odor. [Means for solving the problem]

[0012] The present inventors have conducted extensive research to solve the above problems, and as a result have found that by processing paper with a papermaking softener containing polyoxyalkylene hydrogenated castor oil as component A, a quaternary cationic surfactant containing an imidazoline ring as component B, and a polyether polyol (excluding component A) as component C, it is possible to impart high flexibility and water absorbency to paper while maintaining its strength, and further to efficiently suppress the generation of odors.

[0013] The present invention was completed based on these findings and through further investigation.

[0014] The present invention provides the following aspects. Item 1. A component is polyoxyalkylene hydrogenated castor oil, a quaternary cationic surfactant containing an imidazoline ring as component B; a polyether polyol (excluding the above-mentioned component A) as component C; A paper softener comprising: Item 2. The content of the component A is 20% by mass or more and 70% by mass or less, The content of the component B is 13% by mass or more and 32% by mass or less, Item 2. The papermaking softener according to Item 1, wherein the content of the component C is 12% by mass or more and 50% by mass or less. Item 3. The component A is polyoxyethylene hydrogenated castor oil, Item 3. The papermaking softener according to Item 1 or 2, wherein the polyoxyethylene hydrogenated castor oil has an ethylene oxide addition mole number of 1 to 200. Item 4. The papermaking softener according to any one of Items 1 to 3, wherein Component B is N-stearoylaminoethyl-N-methyl-2-octadecenylimidazolinium methyl sulfate. Item 5. The papermaking softener according to any one of Items 1 to 4, wherein the component C has a number average molecular weight of 200 to 3,000. Item 6. The papermaking softener according to any one of Items 1 to 5, wherein Component C is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol. Item 7. A method for producing paper, comprising a papermaking step of making paper from a pulp slurry in the presence of the papermaking softener according to any one of Items 1 to 6. Item 8. The method for producing paper according to Item 7, wherein in the papermaking step, the total amount of the A component, the B component, and the C component of the papermaking softener added is 0.01 to 3.0 parts by mass per 100 parts by mass of bone dry pulp. Item 9. A paper manufacturing method comprising a step of adhering the papermaking softener according to any one of Items 1 to 6 to base paper. Item 10. Paper treated with the papermaking softener according to any one of items 1 to 6. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a paper softener that can simultaneously impart flexibility and high water absorbency to paper while maintaining the strength of the paper, and that also suppresses the generation of odor. Furthermore, according to the present invention, it is also possible to provide paper treated with these paper softeners and a method for producing paper. DETAILED DESCRIPTION OF THE INVENTION

[0016] The papermaking softener according to the first embodiment of the present invention is characterized by containing polyoxyalkylene hydrogenated castor oil as component A, a quaternary cationic surfactant containing an imidazoline ring as component B, and a polyether polyol (excluding component A) as component C. By virtue of having such a constitution, the papermaking softener according to the first embodiment of the present invention can impart high flexibility to paper while maintaining its strength. Moreover, odor generation is extremely suppressed.

[0017] A papermaking softener according to a second embodiment of the present invention is characterized by containing 20% ​​by mass or more and 70% by mass or less of component A, 13% by mass or more and 32% by mass or less of component B, and 12% by mass or more and 50% by mass or less of component C. By having such a constitution, the papermaking softener according to the second embodiment of the present invention can impart softness, high water absorbency, and odor suppression to paper while maintaining the strength of the paper.

[0018] The papermaking softener of the present invention, paper using the papermaking softener, and a paper manufacturing method will be described in detail below. In the following description, the papermaking softener according to the first embodiment will be described first, followed by the papermaking softener according to the second embodiment. In the description of the papermaking softener according to the second embodiment, explanations of matters common to the first embodiment will be omitted as appropriate.

[0019] 1. Paper softener First Embodiment The paper softener according to the first embodiment of the present invention contains components A, B, and C. Each of the components A, B, and C may be used alone or in combination of two or more.

[0020] Component A is polyoxyalkylene hydrogenated castor oil. The polyoxyalkylene hydrogenated castor oil may contain propylene oxide units. The polyoxyalkylene hydrogenated castor oil is a compound in which alkylene oxide is added to hydrogenated castor oil. Hydrogenated castor oil is well known and is readily available as a commercially available product.

[0021] In polyoxyalkylene hydrogenated castor oil, the raw material hydrogenated castor oil is superior to castor oil in odor suppression. Examples of alkylene oxide units include ethylene oxide units, propylene oxide units, and butylene oxide units, which are used to impart high flexibility and odor suppression to paper while maintaining paper strength. Specific examples include ethylene oxide, 1,2-propylene oxide, 1,3-propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, and isobutylene oxide.

[0022] The alkylene oxide unit may be one type alone or two or more types. When two or more types are contained, the polyalkylene oxide may be a block copolymer or a random copolymer.

[0023] In the polyoxyalkylene hydrogenated castor oil, the number of moles of alkylene oxide units added is not particularly limited, but from the viewpoint of imparting high flexibility and water absorbency to the paper while maintaining the strength of the paper, it is preferably 1 to 200, more preferably 2 to 150, and even more preferably 6 to 50.

[0024] Component B is a quaternary cationic surfactant containing an imidazoline ring. Examples of quaternary cationic surfactants containing an imidazoline ring include N-stearoyloxyethyl-N-methyl-2-decylimidazolinium chloride, N-stearoyloxyethyl-N-ethyl-2-decylimidazolinium chloride, N-stearoyloxyethyl-N-methyl-2-decylimidazolinium methyl sulfate, N-stearoyloxyethyl-N-methyl-2-dodecylimidazolinium chloride, N-palmitoyloxyethyl-N-methyl-2-decylimidazolinium chloride, and N-stearoylaminoethyl-N-methyl-2-octadecenylimidazolinium methyl sulfate. From the viewpoint of imparting high paper flexibility and odor suppression while maintaining paper strength, N-stearoylaminoethyl-N-methyl-2-octadecenylimidazolinium methyl sulfate is preferred.

[0025] Component C is a polyether polyol (excluding component A). A typical example of a polyether polyol is an alkylene oxide adduct of a dihydric alcohol. This is obtained by using a dihydric alcohol as an initiator and ring-opening polymerizing an alkylene oxide (cyclic ether) under alkaline conditions. Specific examples of dihydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tetraethylene glycol, 1,2-pentanediol, 1,5-pentanediol, 1,4-butanediol, and 1,6-hexanediol. Also contemplated are alkylene oxide adducts of polyhydric alcohols using trihydric or higher polyhydric alcohols as initiators. Examples of polyhydric alcohols include glycerin, diglycerin, polyglycerin, sorbitol, xylitol, and pentaerythritol.

[0026] The cyclic ether may be, for example, a 3- to 6-membered cyclic ether compound having one oxygen atom in the ring. Specific examples of the cyclic ether include compounds (monoepoxides) having a 3-membered cyclic ether group, such as ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, trimethylethylene oxide, tetramethylethylene oxide, butadiene monoxide, styrene oxide, α-methylstyrene oxide, epichlorohydrin, epifluorohydrin, epibromohydrin, glycidol, butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, 2-chloroethyl glycidyl ether, o-chlorophenyl glycidyl ether, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, cyclohexene oxide, dihydronaphthalene oxide, and vinylcyclohexene monoxide; and compounds having a 4- to 6-membered cyclic ether group, such as oxetane, tetrahydrofuran, and tetrahydropyran.

[0027] The alkylene oxide adduct of a dihydric alcohol has the structure H-(OL2)m-OH, as shown in the following general formula. [ka]

[0028] In the general formula, H represents a hydrogen element, O represents an oxygen element, and m is an integer of 2 or more.

[0029] <H-(OL2) m Structural unit consisting of -OH> L2 represents an alkylene group. The alkylene group is not particularly limited, and examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a propylene group [-CH(CH3)CH2-], an n-butylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], a hexamethylene group [-(CH2)6-], a heptamethylene group [-(CH2)7-], an octamethylene group [-(CH2)8-], a nonamethylene group [-(CH2)9-], a decamethylene group [-(CH2) 10 -], etc. Furthermore, L2 may be the same or different.

[0030] From the viewpoint of the high hydrophilicity of the structural unit, or from the viewpoint of the reactivity of the monomer that is the raw material of the polyalkylene oxide represented by the structural unit consisting of H-(OL2)m-OH (ease of synthesis of polyalkylene oxide), or from the viewpoint of the ease of availability of the monomer, L2 is preferably an alkylene having 1 to 4 carbon atoms, more preferably an alkylene having 2 to 3 carbon atoms, and even more preferably an alkylene having 3 carbon atoms. Furthermore, from the viewpoint of the fluidity, viscosity, and ease of handling of the polymer, the number average molecular weight is preferably 200 to 4000, more preferably 400 to 2000. Therefore, m in the H-(OL2)m-OH is preferably 2 to 90, more preferably 3 to 70.

[0031] L2 may or may not have a substituent. When present, the number of substituents per L2 may be one or more, preferably one. When there are multiple substituents, they may be the same or different. The substituent in L2 is not particularly limited, but is preferably at least one selected from the group consisting of alkyl groups, unsaturated aliphatic hydrocarbon groups, haloalkyl groups, alkoxy groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, alkenyloxycarbonyl groups, alkoxyalkyl groups, alkenyloxyalkyl groups, alkynyloxyalkyl groups, haloalkoxyalkyl groups, alkoxy-poly(alkyloxy)alkyl groups, acyloxyalkyl groups, halogens, (meth)acryloyloxyalkyl groups, and (meth)acryloyloxyalkoxyalkyl groups. In the present invention, (meth)acrylic acid represents at least one of acrylic acid and methacrylic acid. The same applies to structures derived from (meth)acrylic acid (e.g., (meth)acryloyl groups, etc.).

[0032] <Second embodiment> The papermaking softener of the second embodiment of the present invention, like the first embodiment, contains polyoxyalkylene hydrogenated castor oil as component A, a quaternary cationic surfactant containing an imidazoline ring as component B, and a polyether polyol (excluding component A) as component C.

[0033] However, the papermaking softener of the second embodiment is characterized in that the content of the A component is 20% by mass or more and 70% by mass or less, the content of the B component is 13% by mass or more and 32% by mass or less, and the content of the C component is 12% by mass or more and 50% by mass or less. By maintaining the blending ratios in the above ranges, it is possible to impart high flexibility, odor suppression, and water absorbency to the paper while maintaining the strength of the paper. Preferred combinations of the content ranges of the A component, the B component, and the C component are exemplified below.

[0034] Preferred ranges: 10% by mass or more and 80% by mass or less of the A component, 10% by mass or more and 50% by mass or less of the B component, and 10% by mass or more and 60% by mass or less of the C component More preferred ranges: 20% by mass or more and 70% by mass or less of the A component, 12% by mass or more and 32% by mass or less of the B component, and 12% by mass or more and 50% by mass or less of the C component. More preferred ranges: 40% by mass or more and 60% by mass or less of the A component, 13.5% by mass or more and 23% by mass or less of the B component, and 20% by mass or more and 45% by mass or less of the C component.

[0035] The papermaking softeners of the first and second embodiments may contain other additives in addition to components A, B, and C. Examples of other additives include known additives commonly used in papermaking softeners, such as dry strength improvers, wet strength improvers, coagulants, and thickeners. When other additives are included, the proportions of the additives in the papermaking softeners of the first and second embodiments are, for example, 1 to 200 ppm of coagulant and 0.05 to 0.15 parts by mass of thickener relative to the pulp. Examples of coagulants include polydiallyldimethylammonium chloride (pDADMAC) or its derivatives, copolymers of diallyldimethylammonium chloride and other monomers, polyacrylamide, polyamine, polyethyleneimine, 2-(methacryloyloxy)ethyltrimethylammonium chloride polymers, and modified polyethyleneimine. Examples of thickeners include polyethylene oxide-based thickeners (such as the "ALKOX" series manufactured by Meisei Chemical Industry Co., Ltd.).

[0036] The papermaking softeners of the first and second embodiments may or may not contain a solvent in addition to the components A, B, and C. The solvent is not particularly limited, but preferably includes water, alcohols such as isopropyl alcohol, ethylene glycol, propylene glycol, and the like. Only one solvent may be used, or two or more may be mixed. The components A, B, and C are preferably dispersed in the solvent. For example, by using water as the solvent, the papermaking softeners of the first and second embodiments can be in the form of an aqueous emulsion in which the components A, B, and C are dispersed in a solvent containing water.

[0037] In the paper softeners of the first and second embodiments, the method for dispersing or dissolving the components A, B, and C in water is not particularly limited, and examples thereof include phase inversion emulsification, phase inversion emulsification after adding a surfactant or inorganic salt, and mechanical dispersion, which involves mechanical dispersion. Mechanical dispersion methods include methods in which the components are uniformly dispersed using various known emulsifiers such as a homomixer, a high-pressure discharge homogenizer, a high-shear rotary emulsifying disperser, and an ultrasonic emulsifier. The dispersion method may be a single method or a combination of two or more methods.

[0038] When the papermaking softeners of the first and second embodiments are in the form of an aqueous emulsion or an aqueous solution, the total content of components A, B, and C in the papermaking softeners of the first and second embodiments is preferably 10 to 40% by mass, and more preferably 15 to 30% by mass.

[0039] From the viewpoint of imparting high flexibility and even high water absorbency to paper while maintaining the strength of the paper, it is particularly preferable that the papermaking softener of the present invention satisfies the configurations of both the papermaking softeners of the first and second embodiments.

[0040] 2. Paper and its manufacturing method The paper of the present invention can be suitably produced, for example, by a method including a papermaking step in which a pulp slurry is made in the presence of the papermaking softener of the first or second embodiment, respectively. The paper of the present invention can also be suitably produced, for example, by adhering the papermaking softener of the first or second embodiment to base paper. Furthermore, these production methods can also be used in combination, by first preparing base paper through a papermaking step in which a pulp slurry is made in the presence of the papermaking softener of the first or second embodiment, and then adhering the papermaking softener of the first or second embodiment to the obtained base paper. Details of the papermaking softeners of the first and second embodiments are as described above.

[0041] In the papermaking process, the total amount of components A, B, and C added to the papermaking softeners of the first and second embodiments is preferably 0.01 to 5.0 parts by mass, more preferably 0.01 to 2.0 parts by mass, and even more preferably 0.05 to 0.5 parts by mass, per 100 parts by mass of bone-dry pulp. Also, when the papermaking softeners of the first and second embodiments are applied to base paper, the total amount of components A, B, and C added to the base paper is preferably within these ranges.

[0042] Papermaking from the pulp slurry can be carried out by a method using a known papermaking machine. The papermaking machine may be any device capable of dewatering the pulp slurry on a wire. Examples of papermaking machines include suction breast formers (cylinder type, Fourdrinier type), twin-wire formers, cylinder formers (C-wrap, S-wrap), and crescent formers. In addition to continuous papermaking machines such as Fourdrinier papermaking machines, batch-type pulp molding machines, which add the pulp slurry to a wire-formed mold frame and then dewater it from below the wire to produce a molded body, are also included in the category.

[0043] Furthermore, the method for adhering the papermaking softeners of the first and second embodiments to the surface of the base paper is not particularly limited as long as the components A, B, and C are adhered to the surface of the base paper, and examples thereof include coating by a spray method, coating by a printing machine using a flexographic or gravure method, coating by a size press, a gate roll coater, a bill blade coater, and a calendar.

[0044] Applications of the paper of the present invention include household paper such as tissue paper, toilet paper, towel paper, and kitchen paper, as well as general paper such as printing paper and wrapping paper. Paper treated with the papermaking softener of the first embodiment combines high flexibility and high strength, and paper treated with the papermaking softener of the second embodiment combines flexibility and high water absorbency, and therefore, among household paper, they are particularly suitable for use as tissue paper and toilet paper, for which odor control is important.

[0045] Pulp raw materials constituting the paper or base paper of the present invention include bleached softwood kraft pulp (NBKP), bleached hardwood kraft pulp (LBKP), groundwood pulp (GP), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), deinked pulp (DIP), etc. Pulp raw materials can also be used from recycled paper such as newspapers, magazines, corrugated cardboard, and deinked paper. The paper of the present invention may also contain a mixture of the above pulp raw materials with synthetic fibers such as rayon, polyamide, polyimide, polyester, polyolefin, and polyvinyl alcohol.

[0046] In producing the paper of the present invention, various additives such as fillers, aluminum sulfate, sizing agents, dry strength agents, wet strength agents, humectants, retention aids, drainage aids, dyes, and fragrances may be used as needed to achieve the physical properties required for each type of paper. These additives may be used alone or in combination of two or more. Furthermore, these additives may be premixed with the papermaking softener of the first or second embodiment and added to the pulp slurry to produce the paper of the present invention, or they may be attached to the base paper.

[0047] Examples of fillers include inorganic fillers such as kaolin, calcined kaolin, delaminated kaolin, illite, heavy calcium carbonate, light calcium carbonate, light calcium carbonate-silica composite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, etc. Only one type of filler may be used, or two or more types may be mixed and used.

[0048] Examples of sizing agents include fatty acid soap sizing agents such as sodium stearate, aqueous emulsions of rosin, fortified rosin, rosin ester, aqueous emulsions of alkyl ketene dimer, aqueous emulsions of alkenyl succinic anhydride, aqueous emulsions of 2-oxetanone, aqueous emulsions of paraffin wax, cationic sizing agents obtained by the reaction of carboxylic acid with polyamine, aqueous emulsions of reaction products of aliphatic oxyacid with aliphatic amine or aliphatic alcohol, anionic and cationic styrene-based sizing agents, etc. Only one type of sizing agent may be used, or two or more types may be mixed and used.

[0049] Examples of dry strength improvers include anionic polyacrylamide, cationic polyacrylamide, amphoteric polyacrylamide, cationized starch, amphoteric starch, etc. One type of dry strength improver may be used alone, or two or more types may be used in combination.

[0050] Examples of wet strength improvers include polyamide-epichlorohydrin resins, melamine-formaldehyde resins, and urea-formaldehyde resins. Anionic polyacrylamides may also be used in combination. One type of wet strength improver may be used alone, or two or more types may be mixed together.

[0051] Examples of the moisturizing agent include polyhydric alcohols such as glycerin, sorbitol, polyethylene glycol, etc. One type of moisturizing agent may be used alone, or two or more types may be used in combination.

[0052] The retention aid may be an anionic, cationic, or amphoteric high-molecular-weight polyacrylamide, a combination of silica sol and cationized starch, or a combination of bentonite and cationic high-molecular-weight polyacrylamide. One type of retention aid may be used alone, or two or more types may be mixed together.

[0053] Examples of the drainage improver include polyethyleneimine, cationic, amphoteric, or anionic polyacrylamide, etc. One type of drainage improver may be used alone, or two or more types may be used in combination.

[0054] Furthermore, when the papermaking softeners of the first and second embodiments are applied to base paper, they can be used in combination with known additives used in the surface coating of base paper, such as surface strength improvers such as starch, polyvinyl alcohol, and acrylamide polymers, dyes, coating colors, moisturizing agents, surface sizing agents, and anti-slip agents. [Example]

[0055] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0056] Example 1 To a 200 ml glass beaker, 68 g of Brownon CW-10 (polyoxyethylene (EO) 10 mol) hydrogenated castor oil, Aoki Oil Industries Co., Ltd.) as component A, 26.7 g of Cationic SF-75PA (N-stearoylaminoethyl-N-methyl-2-octadecenylimidazolinium methyl sulfate 75%, Sanyo Chemical Industries Co., Ltd.) as component B, and 12 g of Sannix PP-400 (polypropylene glycol number average molecular weight 400, Sanyo Chemical Industries Co., Ltd.) as component C were sequentially added, stirred at 60 °C for 30 minutes, and then cooled to below 40 °C to obtain 106.7 g of a homogeneous paper softener (100 g of active ingredient). The mass ratios of components A, B, and C are shown in Table 1.

[0057] Example 2 To a 200 ml glass beaker, 60 g of Brownon CW-10 as component A, 24 g of Cationic SF-75PA as component B, and 22 g of Sannix PP-400 as component C were added in that order, and after stirring at 60°C for 30 minutes, the mixture was cooled to below 40°C, yielding 106 g of a homogeneous paper softener (100 g of active ingredient). The pure proportions (mass ratios) of components A, B, and C are shown in Table 1.

[0058] Example 3 To a 200 ml glass beaker, 44 g of Brownon CW-10 as component A, 18 g of Cationic SF-75PA as component B, and 42.5 g of Sannix PP-400 as component C were added in that order, and after stirring at 60°C for 30 minutes, the mixture was cooled to below 40°C, yielding 104.5 g of a homogeneous paper softener (100 g of active ingredient). The pure proportions (mass ratios) of components A, B, and C are shown in Table 1.

[0059] Example 4 To a 200 ml glass beaker, 20 g of Brownon CW-10 as component A, 42 g of Cationic SF-75PA as component B, and 48.5 g of Sannix PP-400 as component C were added in that order, stirred at 60°C for 30 minutes, and then cooled to below 40°C to obtain 110.5 g of a homogeneous paper softener (100 g of active ingredient). The pure proportions (mass ratios) of components A, B, and C are shown in Table 1.

[0060] Example 5 The same procedure as in Example 3 was carried out except that SANNICS PP-2000 (polypropylene glycol number average molecular weight 2000, manufactured by Sanyo Chemical Industries, Ltd.) was used as component C.

[0061] Example 6 To a 200 ml glass beaker, 32.5 g of Brownon CW-10 as component A, 30 g of Cationic SF-75PA as component B, and 45 g of Sannix PP-2000 as component C were added in that order, and after stirring at 60°C for 30 minutes, the mixture was cooled to below 40°C, yielding 107.5 g of a homogeneous paper softener (100 g of active ingredient). The pure proportions (mass ratios) of components A, B, and C are shown in Table 1.

[0062] Example 7 The same procedure as in Example 6 was carried out except that Component C was changed to Newpol PE-62 (polyoxyethylene polyoxypropylene block polymer (EO 10 mol PO 30 mol) number average molecular weight 2200, manufactured by Sanyo Chemical Industries, Ltd.).

[0063] Example 8 The same procedure as in Example 2 was carried out, except that Component A was changed to Brownon CW-25 (polyoxyethylene (EO 25 mol) hydrogenated castor oil, manufactured by Aoki Oil & Fat Industries Co., Ltd.).

[0064] Example 9 The same procedure as in Example 3 was carried out except that BRAWNON CW-25 was used as component A and SANIX PP-2000 was used as component C.

[0065] Example 10 The same procedure as in Example 9 was carried out except that Newpol PE-62 was used as component C.

[0066] Example 11 The same procedure as in Example 6 was carried out except that polyoxyethylene (EO 25 mol) hydrogenated castor oil was used as component A.

[0067] Example 12 The same procedure as in Example 3 was carried out except that Component A was changed to Brownon CW-200 (polyoxyethylene (EO 200 mol) hydrogenated castor oil, manufactured by Aoki Oil & Fat Industries Co., Ltd.).

[0068] Examples 13 to 15 The components were blended in the purity ratios shown in Table 2, except that polyoxypropylene polyoxyethylene (PO 6 moles, EO 10 moles) hydrogenated castor oil was used as component A.

[0069] Comparative Example 1 Component A, Brownon CW-10 (polyoxyethylene (EO 10 mol) hydrogenated castor oil, Aoki Oil & Fat Industries Co., Ltd.), was heated to 40°C to obtain a paper softener.

[0070] [Comparative Examples 2, 3, and 7] The components A, B, and C were mixed in the pure proportions (mass ratio) shown in Table 3, stirred at 60°C for 30 minutes, and then cooled to 40°C or below to obtain a uniform paper softener.

[0071] Comparative Example 4 To a 300 ml separable flask were added 85.6 g of ion-exchanged water, 6.1 g of Coatamine 86W (28% stearyltrimethylammonium chloride, product of Kao), and 8.3 g of polyoxypropylene polyoxyethylene (6 moles PO, 10 moles EO block copolymer) hydrogenated castor oil, in that order, and the mixture was stirred at 60°C for 30 minutes. After cooling to below 40°C, 100 g of paper softener in the form of an aqueous emulsion (10% by mass of the total active ingredients of components A and B) was obtained. The ratio (by mass) of components A and B is shown in Table 1.

[0072] Comparative Example 5 The component B, cationic SF-75PA (N-stearoylaminoethyl-N-methyl-2-octadecenylimidazolinium methyl sulfate 75% product, manufactured by Sanyo Chemical Industries, Ltd.), was heated to 40° C. to obtain a paper softener.

[0073] Comparative Example 6 Only component C, Sannix PP-400 (component C), was used as the fabric softener.

[0074] Comparative Example 8 A 300 ml separable flask was charged with 80 g of purified glycerin, 10 g of propylene glycol, 8.6 g of Kao Sorbitol (70% sorbitol), 3 g of Brownon BR-420 (polyoxyethylene (EO 20 moles) castor oil), and 3.3 g of Alanone ALE (30% N-lauroyl-N-methyl-β-alanine sodium, product of Shinkawa Fine Chemicals), and the mixture was stirred at 60°C for 30 minutes. The mixture was then cooled to below 40°C, yielding 104.9 g of a homogeneous paper softener (100 g of active ingredient).

[0075] Comparative Example 9 A 300 ml separable flask was charged with 80 g of purified glycerin, 10 g of propylene glycol, 8.6 g of Kao Sorbitol (70% sorbitol), 3 g of Brownon CW-40 (polyoxyethylene (EO 40 mol) hydrogenated castor oil), and 1.1 g of Viewlite LCA (polyoxyethylene (EO 3 mol) sodium lauryl ether acetate 93% Shinkawa Fine Chemicals product), and the mixture was stirred at 60°C for 30 minutes. The mixture was then cooled to below 40°C, yielding 102.7 g of a homogeneous paper softener (100 g of active ingredient).

[0076] Comparative Example 10 The same procedure as in Comparative Example 8 was carried out, except that Amphitol 20AB (lauric acid amidopropyl betaine 30% product, product of Kao) was used as component B.

[0077] [Table 1]

[0078] [Table 2]

[0079] [Table 3]

[0080] [Table 4]

[0081] In Tables 1, 2, 3, and 4, "EO" means ethylene oxide units, and "PO" means propylene oxide units. The number of moles after "EO" and "PO" means the number of moles of added ethylene oxide units and propylene oxide units, respectively. For example, the notation "EO 6 moles" means that the number of moles of added ethylene oxide units is 6.

[0082] [Paper making method] Hardwood bleached kraft pulp (LBKP eucalyptus) and softwood bleached kraft pulp (NBKP beech) were weighed out in a mass ratio of 8:2, and the mixture was disintegrated using a disintegrator (Kumagaya Riki Co., Ltd.). The mixture was then beaten in a beater (Kumagaya Riki Co., Ltd.) to a Canadian Standard freeness of 400 ml and a consistency of 1.0%. The basis weight was 17 g / m². 2 Each softener obtained above was added to the pulp at a pure content of 0.3% by mass (the total amount of components A, B, and C added was 0.3% by mass) and stirred for 1 minute. Next, Alcox SW (registered trademark, manufactured by Meisei Chemical Industry Co., Ltd.) was added to the pulp at a pure content of 0.1% by mass using a square sheet machine, and paper was made using a 100 mesh, pressed at 0.40 MPa for 1 minute, and dried in a drum dryer at 105°C for 60 seconds to obtain a pulp sheet (paper).

[0083] [Evaluation method] The obtained pulp sheet was conditioned under standard conditions (temperature 23°C, humidity 50%) for 24 hours, and then evaluated for the following items. The results are shown in Tables 1 to 3.

[0084] [Flexibility] Eight experienced monitors evaluated the flexibility of each pulp sheet on a 5-point scale based on the following criteria, and the average value was rounded off. The results are shown in Tables 1 to 4. 5: Particularly excellent 4: Excellent 3: Normal 2: Slightly inferior 1: Inferior

[0085] [Clark is scary] The Clark stiffness of each pulp sheet was measured in accordance with JIS 8143 under standard conditions of 23°C temperature and 50% humidity. The paper width was 20 mm. A smaller value indicates higher flexibility. The results are shown in Tables 1 to 4.

[0086] [Practical water absorbency] Each pulp sheet was cut into 7cm x 7cm pieces and weighed. 100ml of distilled water (25°C) was placed in a glass petri dish (150mm diameter), and the cut pulp sheet was immersed for 30 seconds. It was then removed with tweezers, excess water was absorbed with filter paper, and the weight was measured after a total of 45 seconds from the time of immersion. A higher value indicates higher water absorbency. The results are shown in Tables 1 to 4. Practical water absorbency (%) = [(sheet weight after water absorption - sheet weight before water absorption) / (sheet weight before water absorption)] × 100

[0087] [Tensile strength] The tensile strength of each pulp sheet was measured under standard conditions of 23°C and 50% humidity using a method compliant with JIS P8113. Using a Shimadzu AUTOGRAPH AG-X, the test specimen was 25 mm wide, had a test length (average grip line spacing) of 150 mm, and was stretched at a rate of 20 mm / min. The results are shown in Tables 1 to 4.

[0088] [Odor] 2g of the active ingredient in the fabric softener composition was placed in a wide-mouth standard SV-50A bottle manufactured by Nichiden Rika Glass Co., Ltd., and 18g of distilled water was added to make a total of 20g, followed by 1g of 10% caustic soda solution, and the bottle was stored at 40°C for 2 hours. After storage, eight expert panelists evaluated the strength of the sample's offensive odor perceived at the bottle opening on a 5-point scale (1 to 5; 1 being the weakest and 5 being the strongest), and the average was rounded off.

Claims

1. Component A is polyoxyalkylene hydrogenated castor oil, a quaternary cationic surfactant containing an imidazoline ring as component B; a polyether polyol (excluding the above-mentioned component A) as component C; Including, The content of the component A is 20% by mass or more and 70% by mass or less, The content of the component B is 13% by mass or more and 32% by mass or less, A paper softener, wherein the content of the component C is 12% by mass or more and 50% by mass or less.

2. The component A is polyoxyethylene hydrogenated castor oil, 2. The papermaking softener according to claim 1, wherein the polyoxyethylene hydrogenated castor oil has an ethylene oxide addition mole number of 1 to 200.

3. 3. The paper softener according to claim 1, wherein the component B is N-stearoylaminoethyl-N-methyl-2-octadecenylimidazolinium methyl sulfate.

4. The papermaking softener according to any one of claims 1 to 3, wherein the number average molecular weight of the component C is 200 to 3,000.

5. The papermaking softener according to any one of claims 1 to 4, wherein the component C is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol.

6. A method for producing paper, comprising a papermaking step of making paper from a pulp slurry in the presence of the papermaking softener according to any one of claims 1 to 5.

7. 7. The paper manufacturing method according to claim 6, wherein in the papermaking process, the total amount of the A component, the B component, and the C component of the papermaking softener added is 0.01 to 3.0 parts by mass per 100 parts by mass of bone dry pulp.

8. A method for producing paper, comprising a step of adhering the papermaking softener according to any one of claims 1 to 5 to base paper.

9. Paper treated with the papermaking softener according to any one of claims 1 to 5.

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