Paper treatment agent, paper using same, and method for improving texture of paper

Abstract

Provided are a paper treatment agent that forms gel on paper when applied thereto to thereby retain moisture, originating from the treatment agent, on the paper and impart a smooth and sleek feel that is unique to the gel on the paper as well as a paper using the same and a method for enhancing the texture of the paper. The paper treatment agent according to the present invention includes (A) a polyhydric alcohol; (B) at least one selected from an alkyl phosphate ester salt and a polyoxyalkylene alkyl ether phosphate ester salt with each alkyl group having 6 to 28 carbon atoms; and (C) water, wherein the water (C) is contained therein in an amount greater than 10% by mass and less than 40% by mass.

Description

TECHNICAL FIELD

[0001] The present invention relates to a paper treatment agent, a paper using the same, and a method for improving paper texture.BACKGROUND ART

[0002] Paper products such as toilet papers and tissues are required to have soft and moist textures, and paper products treated with paper treatment agents containing moisturizing ingredients, such as moisturized tissue with a soft touch, are widely used throughout the year. These paper products, such as moisturized tissue, are coated with a paper treatment agent that contains a polyhydric alcohol such as glycerin for providing softness.

[0003] Further, of the papers that are treated with paper treatment agents containing moisturizing ingredients, moisturizing tissues are often used for blowing the nose, and a product having a favorable texture such as the one exhibiting reduced surface friction for reducing the burden on the skin has been required. It is also desired for papers, intended to provide moisture-retaining properties, to have textures that commercially match the user's taste.

[0004] Heretofore, various measures have been taken to solve technical problems for improving soft and moist texture. For example, Patent document 1 takes advantage of the water absorbency of hydrophilic polymers for improving the moist feeling. However, water-soluble polymers require time and effort to uniformly disperse themselves, and therefore make the processes of producing chemical agents complex. Further, water-soluble polymers cause significant thickening, which in turn necessitates no choice but limitation on their content. Patent document 2 attempts to improve moist feeling using a chemical agent having both glycerin and 1,3-propanediol, but the effect is not sufficient. Patent Document 3 seeks to enhance the texture through the use of a linear alcohol or fatty acid and an anionic surfactant. However, it does not address the structural attributes of alkyl phosphate ester salts, which in turn presents an opportunity for further refinement. Patent documents 4 and 5 seek to improve the texture through the use of alkyl phosphate ester salts. However, they do not study the moist content in their chemical agents and their effects are insufficient as well.

[0005] Patent document 6 proposes a chemical agent comprised of a gel composition but it is difficult to uniformly soak the agent in tissue paper as is, and it requires complicated processes such as heating and dilution to fluidize the agent, as well as an extended drying time for the dilution water. Additionally, its coated paper lacks satisfactory texture.

[0006] Patent document 7 proposes a chemical agent that is highly stable and has favorable texture using a production process by which emulsion products of, for example, cosmetics are prepared in advance and used as ingredients.PRIOR ART DOCUMENTSPatent Documents

[0007] Patent document 1: JP-A-2009-263837

[0008] Patent document 2: JP-A-2016-193042

[0009] Patent document 3: JP-A-2019-099938

[0010] Patent document 4: JP-A-2014-065986

[0011] Patent document 5: JP-A-2009-243022

[0012] Patent document 6: JP-A-2007-203089

[0013] Patent document 7: JP-A-2020-204142SUMMARY OF INVENTIONTechnical Problem

[0014] However, Patent Document 7 requires the production of emulsified cosmetic products or chemical agents, which is a process that is both complex and time-consuming to produce. No known technique has yet been attempted for imparting the texture in the field of paper treatment agent containing moisturizing ingredient(s) by means of remaining non-gelled before application to paper but forming gel on paper only after being applied to the paper. The inventor has focused their study on a type of surfactant that can form gel after-application to paper, and continued their study based on an idea that such surfactant potentially creates a unique, previously unheard-of texture. However, this gel-forming capability on paper may be compromised depending on the formulation or additive amount of the emulsified cosmetic products, failing to achieve a smooth and sleek feel that is unique to the gel.

[0015] The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a paper treatment agent that forms gel on paper when applied thereto to thereby retain moisture, originating from the treatment agent, on the paper and impart a smooth and sleek feel that is unique to the gel on the paper as well as a paper using the same and a method for enhancing the texture of the paper.Solution to Problem

[0016] The inventor of the present invention diligently conducted studies for solving the above-mentioned objects and has found out that a paper treatment agent containing not only a polyhydric alcohol but also: at least one selected from an alkyl phosphate ester salt and a polyoxyalkylene alkyl ether phosphate ester salt whose alkyl groups each having a specific range of carbon atoms; and water in a specific range of content turns into gel on paper, wherein said gel has unique characteristics that are distinctive from those of any other gels, and these characteristics impart paper a texture having a smooth and sleek feel that is unique to the gel, thus completing the invention.

[0017] That is, the paper treatment agent according to the present invention is characterized by an agent containing (A) a polyhydric alcohol, (B) at least one selected from an alkyl phosphate ester salt and a polyoxyalkylene alkyl ether phosphate ester salt with each alkyl group having 6 to 28 carbon atoms, and (C) water, wherein the water (C) is contained therein in an amount greater than 10% by mass and less than 40% by mass.

[0018] The paper according to the present invention is characterized by a paper treated with the paper treatment agent.

[0019] The method for improving paper texture according to the present invention is characterized by a method comprising treating a paper with the paper treatment agent.

[0020] The method for producing the paper treatment agent according to the present invention is characterized by a method comprising the step of adding the components (A) to (C).

[0021] The paper treatment agent according to the present invention, containing the components (A), (B), and (C) in a specific combination of the amount of the components (C), may form gel having unique characteristics on a coated paper to thereby retain moisture, originating from the treatment agent, on the paper, thus imparting a moist texture and providing the paper with a smooth and sleek feel that is unique to the gel.Advantageous Effects of Invention

[0022] The paper treatment agent according to the present invention forms gel having unique characteristics on a coated paper to thereby retain moisture, originating from the treatment agent, on the paper and impart a smooth and sleek feel that is unique to the gel on the paper. These advantageous effects are so remarkable that they go beyond what any person skilled in the art could have foreseen based on the technical features of the present invention.DESCRIPTION OF EMBODIMENTS

[0023] The present invention will be described in greater detail below.

[0024] The term “texture” as described herein in the present invention particularly encompasses a smooth and sleek feel that is unique to the gel.(Paper Treatment Agent)

[0025] The paper treatment agent of the present invention essentially comprises (A) polyhydric alcohol, (B) at least one selected from an alkyl phosphate ester salt and a polyoxyalkylene alkyl ether phosphate ester salt with each alkyl group having 6 to 28 carbon atoms, and (C) water, wherein the water (C) is contained therein in an amount greater than 10% by mass and less than 40% by mass.(A) Polyhydric Alcohol

[0026] In the paper treatment agent of the present invention, the polyhydric alcohol as the component (A) is a moisturizing agent that improves the moisture absorbency and moisture-retaining property of paper and imparts a moisty feeling and softness to the paper.

[0027] Examples of the polyhydric alcohol as the component (A) include, but are not particularly limited to, glycerin, diglycerin, triglycerin, polyglycerin, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, polypropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polyoxyethylene glycerin ether, isoprene glycol, pentaerythritol, and trimethylolpropane.

[0028] The component may be a sugar alcohol or a sugar. Examples of the sugar alcohol include sorbitol, inositol, glucosyltrehalose, xylitol, erythritol, mannitol, lactitol, fructose, oligosaccharide alcohols, maltitol, reduced palatinose, reduced starch syrup, and reduced starch hydrolysates. Examples of the sugar include fructose, glucose, lactose, xylose, psicose, malt sugar, starch syrup, oligosaccharides, maltose, trehalose, lactose, palatinite, sucrose, isomerized sugar, isomaltooligosaccharides, fructooligosaccharides, galactooligosaccharides, xylooligosaccharides, lactofructose oligosaccharides, soybean oligosaccharides, raffinose, stevia, licorice, saccharin, aspartame, acesulfame K, and sucralose.

[0029] They may be used alone, or two or more of them may be used in combination. Of these, the preferred are glycerin, 1,3-butanediol, 1,2-propanediol, and sorbitol, among which glycerin is more preferred.

[0030] The content of the polyhydric alcohol (A) is not particularly limited but may be, for example, more than or equal to 1% by mass relative to the total amount of the paper treatment agent. It is preferred in terms of improving the texture due to moisture absorbency of the polyhydric alcohol (A) on the coated paper that the content be more than or equal to 10% by mass, more preferably more than or equal to 20% by mass, even more preferably more than or equal to 40% by mass, still more preferably more than or equal to 60% by mass, even still more preferably more than or equal to 70% by mass, particularly preferably more than or equal to 75% by mass, and most preferably more than or equal to 80% by mass relative to the total amount of the paper treatment agent. Further, it is preferred in terms of improving the texture specific to the present invention that the content be less than or equal to 89% by mass, more preferably less than or equal to 85% by mass relative to the total amount of the paper treatment agent. It is also preferred that the content be 10 to 89% by mass, more preferably 20 to 89% by mass, and even more preferably 40 to 89% by mass relative to the total amount of the paper treatment agent.(B) Alkyl Phosphate Ester Salt or Polyoxyalkylene Alkyl Ether Phosphate Ester Salt with Alkyl Group Having 6 to 28 Carbon Atoms

[0031] The paper treatment agent according to the present invention contains, as the component (B), an alkyl phosphate ester salt or polyoxyalkylene alkyl ether phosphate ester salt with alkyl group having 6 to 28 carbon atoms together with (A) a polyhydric alcohol and the agent further contains water (C) in an amount greater than 10% by mass and less than 40% by mass to thereby form gel having unique characteristics on paper and provide paper with a smooth and sleek feel that is unique to the gel.

[0032] The alkyl group in the component (B) may contain any number of carbon atoms so long as it is in a range of 6 to 28. However, it is preferred in terms of imparting a suitable degree of firmness to a gel formed and coated on the paper by the treatment agent that the number of carbon atoms in the alkyl group be 10 or more, more preferably 12 or more, and even more preferably 14 or more. It is preferred in terms of imparting a suitable degree of softness to a gel formed and coated on the paper by the treatment agent that that the number of carbon atoms in the alkyl group be 24 or less, more preferably 22 or less, and even more preferably 20 or less. It is also preferred that the number of carbon atoms be 8 to 24, more preferably 8 to 20, and even more preferably 12 to 18. Also, such an alkyl group may be of a type that is unsaturated or saturated, and the group may be of a type that is linear or branched.

[0033] The alkyl phosphate ester salt (B) according to the present invention can be produced by allowing an alcohol with alkyl group to react with a phosphorylating agent to produce a phosphate ester, followed by neutralizing the phosphate ester. The polyoxyalkylene alkyl ether phosphate ester salt according to the present invention can be produced by, for example, a method in which an alkylene oxide is added to an alcohol to obtain an alkylene oxide adduct, which is then reacted with a phosphorylating agent to obtain a phosphate ester which is then neutralized, or by a method in which an alkylene oxide is added to a phosphate ester that is obtained by reacting an alcohol with a phosphorylating agent, and neutralizing it.

[0034] Examples of the alkylene oxide added to an alcohol include ethylene oxide, propylene oxide, and butylene oxide of which ethylene oxide and propylene oxide are preferred. Two or more different types of alcohols or alkylene oxides may be mixed for use therein to produce alkylene oxide adducts of alcohols. The alkylene oxide may be added randomly or in blocks to add two or more different types of alkylene oxides. The additional polymerization degree of alkylene oxides to alcohols is not particularly limited but it is preferred in terms of imparting a suitable degree of firmness to a gel formed and coated on the paper by the treatment agent that the degree be 30 or lower, more preferably 20 or lower, even more preferably 10 or lower, still more preferably 5 or lower, and particularly preferably 3 or lower.

[0035] Examples of phosphorylating agents to be reacted with the above-described alcohols or alkylene oxide adducts of alcohols include phosphorus pentoxide and phosphoryl chloride.

[0036] Examples of phosphate esters obtained by reacting an alcohol with a phosphorylating agent include monoesters, diesters, and triesters. The content ratios of these monoesters, diesters, and triesters in the reaction product can be adjusted by adjusting, for example, the reaction ratio of alcohol to phosphorylating agent and the reaction time. Typically, the reaction product produced by reacting an alcohol with a phosphorylating agent can be obtained as a mixture of monoesters, diesters, and triesters, with only the monoesters and diesters capable of further reaction with an alkylene oxide. However, even if a triester is present in the reaction product, the reaction with an alkylene oxide can proceed without separating and removing the triester, and therefore, there is no problem even if the treatment agent contains a triester.

[0037] When the phosphoric acid ester obtained by reacting an alcohol with a phosphorylating agent is a diester, the residues of the alcohol esterified and bonded to the phosphoric acid may be the same or different.

[0038] As the alkylene oxide to be further reacted with the phosphoric acid ester obtained by reacting the alcohol with the phosphorylating agent, there may be used ethylene oxide, propylene oxide, or butylene oxide, in a manner same as the case of the alkylene oxide to be added to the alcohol, of which the preferred are ethylene oxide and propylene oxide. The additional polymerization degree of alkylene oxides to the phosphoric acid ester of alcohol is not particularly limited but it is preferred in terms of imparting a suitable degree of firmness to a gel formed and coated on the paper by the treatment agent that the degree be 30 or lower, more preferably 20 or lower, even more preferably 10 or lower, still more preferably 5 or lower, and particularly preferably 3 or lower.

[0039] Examples of linear or branched, saturated or unsaturated alkyl phosphate ester salts include hexyl phosphate ester salts, octyl phosphate ester salts, 2-ethylhexyl phosphate ester salts, nonyl phosphate ester salts, decyl phosphate ester salts, isodecyl phosphate ester salts, undecyl phosphate ester salts, lauryl phosphate ester salts, isolauryl phosphate ester salts, tridecyl phosphate ester salts, isotridecyl phosphate ester salts, myristyl phosphate ester salts, isomyristyl phosphate ester salts, pentadecyl phosphate ester salts, isopentadecyl phosphate ester salts, cetyl phosphate ester salts, hexyldecyl phosphate ester salts, heptadecyl phosphate ester salts, stearyl phosphate ester salts, isostearyl phosphate ester salts, oleyl phosphate ester salts, nonadecyl phosphate ester salts, arachidyl phosphate ester salts, octyldodecyl phosphate ester salts, behenyl phosphate ester salts, lignoceryl phosphate ester salts, decyltetradecyl phosphate ester salts, ceryl phosphate ester salts, and montanyl phosphate ester salts.

[0040] Examples of polyoxyalkylene alkyl ether phosphate ester salts include polyoxyethylene hexyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene octyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene 2-ethylhexyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene decyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene isodecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene lauryl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene isolauryl alcohol ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene tridecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene myristyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene isomyristyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene pentadecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene isopentadecyl alcohol ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene cetyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene hexyldecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene stearyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene isostearyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene oleyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene nonadecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene arachidyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene octyldodecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene behenyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene lignoceryl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene decyltetradecyl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene ceryl ether phosphate ester salts (POE(1) to POE(30)), polyoxyethylene montanyl ether phosphate ester salts (POE(1) to POE(30)), polyoxypropylene hexyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene octyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene 2-ethylhexyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene decyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene isodecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene lauryl ether phosphate ester salts (POP(1) to POP(30)), polyoxyethylene isolauryl alcohol ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene tridecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene myristyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene isomyristyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene pentadecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxyethylene tridecyl alcohol ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene cetyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene hexyldecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene stearyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene isostearyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene oleyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene nonadecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene arachidyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene octyldodecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene behenyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene lignoceryl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene decyl tetradecyl ether phosphate ester salts (POP(1) to POP(30)), polyoxypropylene ceryl ether phosphate ester salts (POP(1) to POP(30)), and polyoxypropylene montanyl ether phosphate ester salts (POP(1) to POP(30)).

[0041] The numerals in parentheses indicate the number of polyoxyethylene (POE) or polyoxypropylene (POP) units.

[0042] Examples of salts constituting the component (B) include, but are not particularly limited to, alkali metal salts, amine salts, and ammonium salts. Examples of the alkali metal salts include, but are not particularly limited to, sodium salts and potassium salts. Examples of the amine salts include, but are not particularly limited to, salts derived from amine compounds.

[0043] The content of the component (B) is not particularly limited but it is preferred in terms of improving the texture by the present invention that the content be more than 0.05% by mass, more preferably more than 0.15% by mass, even more preferably more than 0.5% by mass, and still more preferably more than 1.0% by mass relative to the total amount of the paper treatment agent. It is also preferred for the treatment agent to form a gel having unique characteristics on coated paper that the content be 70% by mass or lower, more preferably 40% by mass or lower, and even more preferably 20% by mass or lower relative to the total amount of the paper treatment agent. It is further preferred that the content be higher than 0.05% by mass and lower than or equal to 70% by mass, more preferably higher than 0.15% by mass and lower than or equal to 70% by mass, even more preferably higher than 0.5% by mass and lower than or equal to 70% by mass, and still more preferably higher than 0.5% by mass and lower than or equal to 40% by mass relative to the total amount of the paper treatment agent.(C) Water

[0044] In the paper treatment agent of the present invention, the component (C) or water is an essential component for exhibiting advantageous effects of the present invention in combined use with the component (B) which is an alkyl phosphate ester salt or a polyoxyalkylene alkyl ether phosphate ester salt.

[0045] Examples of the component (C), namely water, include, but are not particularly limited to an ion-exchanged water, tap water, and sterilized water.

[0046] The contents of water (C) may be higher than 10% by mass and less than 40% by mass relative to the total amount of the paper treatment agent but it is preferred in terms of imparting a suitable degree of softness to a gel formed and coated on the paper by the treatment agent that the content be 11% by mass or higher, more preferably 15% by mass or higher, and even more preferably 20% by mass or higher. It is also preferred in terms of imparting a suitable degree of firmness to a gel formed and coated on the paper by the treatment agent that content be 39% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less. It is also preferred that the content exceeds 10% by mass but remains below 39% by mass, more preferably higher than 10% by mass and lower than or equal to 30% by mass, and even more preferably higher than 10% by mass and lower than or equal to 25% by mass.

[0047] It is preferred for the treatment agent according to the present invention to form a gel having unique characteristics on coated paper that the ratio of the component (B) to the component (C) (Component (B) / Component (C)) be 0.001 or higher, more preferably 0.01 or higher, and even more preferably 0.05 or higher. It is also preferred for the treatment agent to form a gel having unique characteristics on coated paper that the ratio be 8 or lower, more preferably 5 or lower, and even more preferably 2 or lower. It is further preferred that the ratio be 0.001 to 8, more preferably 0.01 to 8, even more preferably 0.01 to 5, and still more preferably 0.1 to 5.(D) Further Component

[0048] The paper treatment agent of the present invention may contain further component(s) (D) as an ingredient(s) other than those described above within the range that does not impair the advantageous effects of the present invention. Examples of such further component include, but are not particularly limited to, for example, an oil component, a surfactant (a nonionic surfactant, an anionic surfactant except for the component (B), a cationic surfactant, an amphoteric surfactant), a moisturizing ingredient other than the component (A)), a thickener, a fungicide, a preservative, an antifoam agent, a fragrance, a colorant, a pH adjuster, an extract, an antioxidant agent, an anti-inflammatory drug, an inorganic mineral, an inorganic salt, and a water-soluble polymer. They may be used alone, or two or more of them may be used in combination.Oil Component

[0049] The oil component mainly improves the texture, such as the oily and moist feeling and the surface feel (smoothness) of treated paper. Examples of the oil component include hydrocarbons, lipids, esters, fatty acids, higher alcohols, silicone oils, waxes, and steroids. They may be used alone, or two or more of them may be used in combination.

[0050] Examples of the hydrocarbons include a liquid paraffin, a paraffin, a solid paraffin, a light isoparaffin, a light liquid isoparaffin, a liquid isoparaffin, ceresin, a microcrystalline wax, a petroleum jelly, a squalane, a polyethylene wax, a polypropylene wax, a hydrogenated polyisobutene, an ethylene-α-olefin-cooligomer, and an ethylene propylene polymer.

[0051] Examples of the lipids include, for example, an avocado oil, an almond oil, a flaxseed oil, an olive oil, a cacao oil, a perilla oil, a camellia oil, a castor oil, a sesame oil, a wheat germ oil, a rice germ oil, a rice bran oil, a sasanqua oil, a safflower oil, a soybean oil, an evening primrose oil, a camellia oil, a corn oil, a rapeseed oil, a Prunus armeniaca kernel oil, a palm kernel oil, a coconut oil, a palm oil, a beef fat, a pork fat, a horse fat, a sheep fat, a shea fat, a cacao fat, a turtle oil, a mink oil, an egg yolk oil, a purcellin oil, a castor oil, a sunflower oil, a jojoba oil, a grape seed oil, a macadamia nut oil, a cotton seed oil, meadowfoam oil, a coconut oil, a peanut oil, a cod liver oil, a rose hip oil, a hardened oil of beef fat, an extremely hardened oil of beef fat, a hardened castor oil, and an extremely hardened palm oil.

[0052] Examples of the esters include a stearic acid alkyl ester, a palmitic acid alkyl ester, a myristic acid alkyl ester, a lauric acid alkyl ester, a behenic acid alkyl ester, an oleic acid alkyl ester, an isostearic acid alkyl ester, a 12-hydroxystearic acid alkyl ester, an undecylenic acid alkyl ester, a lanolin fatty acid alkyl ester, an erucic acid alkyl ester, a coconut oil fatty acid alkyl ester, a stearoyloxystearic acid alkyl ester, an isononanoic acid alkyl ester, a dimethyloctanoic acid alkyl ester, an octanoic acid alkyl ester, a lactic acid alkyl ester, an ethylhexanoic acid alkyl ester, a neopentanoic acid alkyl ester, a malic acid alkyl ester, a phthalic acid alkyl ester, a citric acid alkyl ester, a malonic acid alkyl ester, an adipic acid alkyl ester, an ethylene glycol fatty acid ester, a propanediol fatty acid ester, a butanediol fatty acid ester, a trimethylolpropane fatty acid ester, a pentaerythritol fatty acid ester, a polyglycerin fatty acid ester, a trehalose fatty acid ester, and a pentylene glycol fatty acid ester.

[0053] Examples of the fatty acids include, for example, stearic acid, palmitic acid, myristic acid, lauric acid, behenic acid, oleic acid, isostearic acid, 12-hydroxystearic acid, undecylenic acid, lanolin fatty acid, erucic acid, and stearoyloxystearic acid.

[0054] Examples of the higher alcohols include, for example, lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hexyldecanol, myristyl alcohol, aralkyl alcohol, phytosterol, isostearyl alcohol, and octyldodecanol.

[0055] Examples of the silicone oils include, for example, an amino-modified silicone oil, an epoxy-modified silicone oil, a carboxy-modified silicone oil, a polyether-modified oil, a polyglycerin-modified silicone oil, a dimethylpolysiloxane, a dimethylsilicone, a polyether-modified silicone, a methylphenylsilicone, an alkyl-modified silicone, a higher fatty acid-modified silicone, a methylhydrogen silicone, a fluorine-modified silicone, an epoxy-modified silicone, a carboxy-modified silicone, a carbinol-modified silicone, an amino-modified silicone, a methylpolysiloxane, a methylphenylpolysiloxane, a silicone resin, a dimethicone, a methylhydrogenpolysiloxane, a methylcyclopolysiloxane, an octamethyltrisiloxane, a tetramethylhexasiloxane, and a highly polymerized methylpolysiloxane.

[0056] Examples of the waxes include, for example, a Japan wax, a beeswax, a sumac wax, a lacquer wax, a sugarcane wax, a palm wax, a montan wax, a carnauba wax, a candelilla wax, a rice bran wax, a lanolin, a spermaceti, a reduced lanolin, a liquid lanolin, a hard lanolin, a ceresin, and an ozokerite.

[0057] Examples of the steroids include cholesterol, dihydrocholesterol, and cholesterol fatty acid ester.(Surfactant)

[0058] Of the surfactants, examples of nonionic surfactants include, but are not particularly limited to, a sorbitan fatty acid ester, a polyoxyethylene sorbitan fatty acid ester, a polyoxyethylene fatty acid ester, a polyoxyethylene hardened castor oil, a polyoxyethylene castor oil, a polyoxyethylene hardened castor oil fatty acid ester, a castor oil fatty acid ester, a hardened castor oil fatty acid ester, an ethylene glycol fatty acid ester, a sucrose fatty acid ester, a glycerin fatty acid ester, a diglycerine fatty acid ester, a polyglyceryl fatty acid ester, an organic acid monoglyceride, a polyethyleneglycol monoethanol fatty acid amide, a propylene glycol fatty acid ester, a polyoxyethylene lanolin alcohol ether, a polyoxyethylene alkyl ether, a lauric acid alkanolamide, a polyoxyethylene glycerin fatty acid ester, a polyoxyethylene hardened castor oil pyroglutamic acid fatty diester, a pyroglutamic acid fatty glyceryl, a polyoxyethylene glyceryl pyroglutamic acid fatty diester, and a polyether modified silicone.

[0059] Examples of the anionic surfactants, excluding the component (B), include, but are not particularly limited to, a sulfate, a sulfonate, and a carboxylate. Examples of the sulfates include, but are not particularly limited to, an alkyl sulfate, an alkyl sulfate ester salt, an alkyl ether sulfate, an alkylamide sulfate, and a polyoxyethylene alkyl ether sulfate. Examples of the sulfonates include, but are not particularly limited to, an alkyl sulfonate, an alkyl benzene sulfonate, an alkylnaphthalene sulfonate, a sulfosuccinate ester salt, a sulfo fatty acid ester salt, an α-olefin sulfonate, an alkyloylalkyltaurine salt, and a sodium methyl cocoyl taurate. Examples of the carboxylate include, but are not particularly limited to a fatty acid salt, a N-acyl amino acid salt (such as N-acyl-L-glutamate and N-acyl-L-arginine ethyl-DL-pyrrolidone carboxylate), an alkyl ether carboxylate, and a polyoxyethylene alkyl ether acetate.

[0060] Examples of the cationic surfactant include, but are not particularly limited to, a mono-alkyl trimethyl ammonium salt, a dialkyl dimethyl ammonium salt, an alkylpyridinium salt, an N,N-dialkyloyloxyethyl-N-methyl, N-hydroxyethyl ammonium salt, an alkylamine salt, and a stearyldimethylbenzylammonium salt.

[0061] Examples of the amphoteric surfactant include, but are not particularly limited to, an alkylbetaine, a fatty acid amide propyl betaine, a lauryl hydroxysulfobetaine, a 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lecithin, hydrogenated lecithin, an alkyloxyhydroxypropyl arginine hydrochloride, a lauryl hydroxysultaine, lauriminodipropionate, an undecyl hydroxyethyl imidazolinium betaine sodium, disodium lauriminodiacetate, a lauryl dimethyl amino acetic acid betaine, an N-[3-alkyloxy-2-hydroxypropyl]-L-arginine hydrochloride, an alkyl hydroxy sulfobetaine, an alkyldimethyl amine oxide, a sodium alkylamino dipropionate, a dihydroxyalkyl methylglycine, and a sodium lauryl diaminoethylglycinate.

[0062] Examples of the moisturizing ingredient other than the component (A) include, but are not particularly limited to, amino acids and alkalis / acids having hygroscopic property or salts thereof. Examples of the amino acids include, for example, glycine, valine, leucine, isoleucine, serine, threonine, phenylalanine, arginine, lysine, aspartic acid, glutamic acid, cystine, cysteine, methionine, and tryptophan. Examples of the alkalis / acids having hygroscopic property or salts thereof include trimethylglycine, betaine, pyrophosphoric acid, sodium pyrophosphate, chondroitin sulfate, potassium pyrophosphate, hyaluronic acid, sodium hyaluronate, sodium metaphosphate, potassium polyphosphate, sodium pyrrolidone carboxylate, sodium lactate, sodium chloride, calcium chloride, sodium alginate, and sodium polyacrylate. They may be used alone, or two or more of them may be used in combination.

[0063] It is preferred that the content of the component (D) be less than or equal to 30% by mass, more preferably less than or equal to 10% by mass, even more preferably less than or equal to 5% by mass, and particularly preferably less than or equal to 1% by mass, and most preferably less than or equal to 0.5% by mass relative to the total amount of the paper treatment agent.

[0064] Although the component (D) is optional, it is necessary that it does not inhibit the effect of forming gel when paper is treated with the paper treating agent; that is, it is necessary that it does not inhibit the formation of a network formed by the aqueous base, containing the components (A) and (C), and the component (B) to cause gelation. Examples of such D component that could inhibit gelation include components (D1) as explained below.(D1) Unfavorable Components for Forming Gel

[0065] Examples of components that tend to hinder gel forming effects include components which, when added to the paper treatment agent, cause the oil components to, for example, coalesce or separate, resulting in a non-uniform composition. Such components are less likely to result in a gel having distinguishing physical properties that exhibit smooth and sleek feeling unique to the gel even after the moisture content is evaporated from the composition to which such components are added.

[0066] Examples of such components among the emulsified products having been prepared in advance before being added thereto include emulsified cosmetic products in the forms of cream, milk, or liquid. The term “emulsified cosmetic product” as used herein refers to products that essentially contain an oil component, an aqueous component, and a surfactant serving to emulsify these components, where the oil and aqueous components are emulsified using the surfactant in a manner publicly known in the art.

[0067] The emulsified cosmetic products are emulsions formulated as product specifications, and a high degree of emulsion stability is ensured as a final product. In addition, such a product is not designed to be dispersed in other compositions. Therefore, when added to the paper treatment agent of the present invention, there is a risk of inhibiting gelation. In other words, when the component (D) is added as a raw material that is not formulated as a final product, the raw material can be adjusted so as to be blended uniformly, thereby maintaining uniformity and adjusting the form so that it does not inhibit gelation on the coated paper. However, emulsified cosmetic products, formulated in advance, are composed of a highly sophisticated combination of multiple raw materials, and therefore it is difficult to adjust them so that they can be blended uniformly, and therefore it is also practically impossible to control the form so that it does not inhibit gelation on the coated paper. The emulsified cosmetic product is produced by homogenizing oil and aqueous components that are innately incompatible with each other, and it is therefore known that careful selection of ingredients and formulations is essential to maintain stability. A composition in a stable emulsified state turns unstable once a continuous phase of a different composition is mixed thereinto, and particularly such composition is more likely to cause separation, which tends to inhibit the network of gel from being formed by the components (A) to (C).

[0068] Examples of the emulsified cosmetic product serving as the component (D1) include, but are not particularly limited to, skin cosmetics (basic cosmetics), makeup cosmetics, and hair care cosmetics. The emulsified cosmetic product may take a dosage form of, for example, cream, milk, liquid, or gel. The term “cream” generally refers to an opaque state without fluidity at room temperature (25° C.). The term “milk” generally refers to an opaque state in white appearance with fluidity at room temperature (25° C.). The term “liquid” generally refers to a transparent state with fluidity at room temperature (25° C.). The term “gel” generally refers to a transparent state in appearance without fluidity at room temperature (25° C.). It is particularly preferred that the composition of the present invention do not contain any cosmetic product in the form of cream, milk, or liquid.

[0069] Examples of cosmetic products in the form of cream include cold cream, nourishing cream, vanishing cream, emollient cream, moisturizing cream, moisture cream, night cream, eye cream, hand cream, lip cream, shaving cream, body cream, hair cream, cleansing cream, baby cream, medical cream, skin cream, gel cream, and botanical cream.

[0070] Examples of cosmetic products in the form of milk include nourishing milk, vanishing milk, emollient milk, moisturizing milk, moisture milk, night milk, eye milk, hand milk, shaving milk, body milk, hair milk, cleansing milk, baby milk, medical milk, skin milk, and botanical milk.

[0071] Examples of cosmetic products in the form of liquid include nourishing liquid, vanishing liquid, emollient liquid, moisturizing liquid, moisturizing liquid, night liquid, eye liquid, shaving liquid, body liquid (body lotion), hair liquid (hair lotion), cleansing liquid (cleansing lotion), baby liquid, medical liquid, skin liquid (skin lotion), botanical liquid, lotion, beauty serum, and cleansing oil.

[0072] Examples of cosmetic products in the form of gel include cold gels, nourishing gels, vanishing gels, emollient gels, moisturizing gels, moisture gels, night gels, eye gels, hand gels, lip gels, shaving gels, body gels, hair gels, cleansing gels, baby gels, medical gels, skin gels, and botanical gels.

[0073] The formulation of the above-described emulsified cosmetic product may be determined by reference to the formulation of the conventional emulsified cosmetic products. The emulsified cosmetic product essentially contains an aqueous component (such as water and glycerin), an oil component (such as a hydrocarbon, a higher fatty acid / alcohol, a vegetable oil, an ester oil, and a silicone oil), and a surfactant (such as an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, and a silicone-based surfactant) as main ingredients to which a further component(s) of a pigment / powder (such as talc, calcium carbonate, nylon, metal soap), a solvent (such as butylene glycol, propylene glycol, polyethylene glycol, and isododecane), a thickener, a film-forming material, a tasteful ingredient (such as a colorant, a fragrance, and a pearlizing agent), a functional ingredient (such as a skin whitening ingredient, a barrier function repair ingredient, and a plant extract), and / or a quality preserving agent (such as a preservative, an antioxidant, and a pH adjuster) is / are added as desired. The cosmetic products are generally classified by their dosage formulations into not only the above-listed cosmetic products in the forms of cream, milk, liquid, and gel but also beauty lotions, beauty serums, hair dyes, hair treatments, foundations, shampoos, facial cleansing creams and foams, sunscreens and tanning products, eyebrow inks and eyelash cosmetics, eye make-up, face masks, men's skin cosmetics, lipstick, perfumes and eau de colognes, and nail cosmetics. Cosmetic products have long been recognized as products distributed in the consumer market. Meanwhile, paper treatment agents are also recognized as products of paper to which moisturizing properties are given, such as toilet paper and tissues, in business-to-business transactions between manufacturers of paper treatment agent and manufacturers of paper. These products potentially contain, as compositions, an oil component, an aqueous component, and a surfactant but it is well known that these products are recognized or traded as products that are distinguished by their intended use. Furthermore, there is a clear difference between them in terms of the area or target to which they are applied: cosmetic products are applied to human skin or hair, for example for skin applications, make-up applications, and hair care applications, whereas paper treatment agents are applied to paper.

[0074] The above-listed D1 components (emulsified cosmetic products) may hinder gel formation on pater and prevent a smooth and sleek feel that is unique to the gel from being obtained depending on their formulation or added amounts.

[0075] It is preferred that the paper treatment agent according to the present invention do not substantially contain any emulsified cosmetic product as the component (D1). This substantial un-containment of the emulsified cosmetic product as the component (D1) allows the treatment agent to form a gel having unique characteristics on the coated paper to thereby retain moisture, originating from the treatment agent, on the paper and impart a smooth and sleek feel that is unique to the gel. The meaning of the phrase “do not substantially contain” is not particularly limited so long as the advantageous effects of the present invention are not impaired but is refers to, for example, a state in which it is contained by an amount of less than 0.4% by mass, less than 0.3% by mass, or less than 0.2% by mass based on the whole mass of the paper treatment agent.

[0076] The paper treatment agent of the present invention contains the components (A), (B), and (C), and thus has a low viscosity before being applied to a paper, but after being applied to the paper, its moisture is appropriately retained on the coated paper, thereby exerting the advantageous effects of the present invention. As explained above, the paper treatment agent of the present invention exhibits low viscosity, and therefore allows easy transportation and favorable handling, and the amount of treatment agent adsorbed on the treatment paper can be easily controlled, thus resulting in good operability. Uniform application of the paper treatment agent to paper, pertaining to the texture of the paper, will become favorable as well.

[0077] It is preferred that the paper treatment agent of the present invention have a viscosity, as measured at 60 rpm and 40° C. using a B-type viscometer, of less than 2,000 mPa s, more preferably less than 500 mPa s.

[0078] As a preferred example of the paper treatment agent of the present invention, there may be listed: a paper treatment agent that contains 20 to 89% by mass of the component (A), an alkyl phosphate having an alkyl group having 10 to 22 carbon atoms as the component (B) in an amount higher than 0.5% by mass and less than or equal to 40% by mass, and the component (C) in an amount higher than 10% by mass and less than or equal to 39% by mass relative to the total amount of the paper treatment agent; and a paper treatment agent that contains 20 to 89% by mass of the component (A), a polyoxyalkylene alkyl ether phosphate ester salt having an alkyl group having 10 to 22 carbon atoms as the component (B) in an amount higher than 0.5% by mass and less than or equal to 40% by mass, and the component (C) in an amount higher than 10% by mass and less than or equal to 39% by mass relative to the total amount of the paper treatment agent.(Method for Producing Paper Treatment Agent)

[0079] The method for producing the paper treatment agent according to the present invention includes a step of adding the components (A) to (C).

[0080] The paper treatment agent of the present invention may be produced by uniformly mixing the respective ingredients in accordance with the conventional method. For example, the respective ingredients may be stirred and mixed at a temperature by which the ingredients are dissolved to obtain the paper treatment agent.

[0081] The paper treatment agent of the present invention may be in a state in which the components (A), (B), and (C) are uniformly mixed, or in which the components (A), (B), (C), and (D) are uniformly mixed if the component (D) is further blended, and the state may be, for example, in a molten state, a solubilized state, an emulsified state, or a dispersed state.

[0082] It is preferred that the method for producing the paper treatment agent according to the present invention contain no step of adding the emulsified cosmetic product as the component (D1) after the respective ingredients are stirred and mixed in the step of adding the components (A) to (C).

[0083] As explained above, among the components (D), the component (D1) is a component that is unfavorable for forming gel. Particularly, a process of adding the component (D1) to a uniform composition produced after the components (A), (B), and (C) are uniformly mixed prevents the formation of gel that has unique characteristics of exhibiting a smooth and sleek feel on coated paper.

[0084] The term “uniform” as used herein refers to a state in which no separation can be visually confirmed, and examples of such a state include a state in which no layers are separated into the upper and lower layers after being left to stand.(Paper)

[0085] The paper of the present invention is directed to a paper treated with the paper treatment agent as explained above. As to the paper according to the present invention, a treatment of paper using the paper treatment agent of the present invention allows paper to have a smooth and sleek feel that is unique to the gel.

[0086] Examples of the paper include a tissue paper, a toilet paper, a facial tissue, a pocket tissue, a paper handkerchief, and a paper towel.

[0087] The basis weight of the paper is not particularly limited but preferably is 1 to 50 g / m2, more preferably 5 to 20 g / m2. The ply number (the number of base paper layers) is not particularly limited but preferably is 1 to 5, and more preferably is 2 to 3.(Method for Producing Paper)

[0088] The paper according to the present invention may be produced by, for example, steps 1 and 2 as specified in the following.

[0089] Step 1 is a step of adding (A) a polyhydric alcohol, (B) at least one selected from an alkyl phosphate ester salt and a polyoxyalkylene alkyl ether phosphate ester salt with each alkyl group having 6 to 28 carbon atoms, and (C) water to produce a paper treatment agent having a water content higher than 10% by mass and less than 40% by mass.

[0090] Step 2 is a step of treating paper with the above-mentioned paper treatment agent to form gel on the paper.

[0091] The step 1 involves the preparation of a uniform composition having the components (A) to (C). This paper treatment agent is liquid.

[0092] The step 2 involves the treatment of paper with the paper treatment agent and evaporation of moisture from the paper treatment agent in the treatment process to thereby form gel on paper. The term “gelation” as used herein refers to, but is not particularly limited to, a state having decreased fluidity which occurs due to, for example, the evaporation of moisture from the liquid paper treatment agent in a container, resulting in a significant increase in viscosity. Specifically, it refers to a state where the upper surface resists tilting when the container is tilted and where the agent exhibits great difficulty flowing when an attempt is made to drip it from the container.

[0093] Examples of the method for treating paper with the paper treatment agent in the step 2 include, but are not particularly limited to, a method of applying the treatment agent onto paper. Examples of the method of applying the agent onto paper include, but are not particularly limited to, transcription and spraying. Examples of the system for applying the agent onto paper using these methods include a flexographic printing system, a gravure printing system, a spray system, and a rotor dampening system. In the flexographic printing system, a flexographic printing machine that is a type of the letterpress printing machines is used to transfer a paper treatment agent onto paper using a roller equipped with a machine plate made of, for example, rubber or synthetic resin whose surface has been engraved. In the gravure printing system, a gravure printing machine that is a type of the intaglio printing machines is used to transfer a paper treatment agent onto paper using a roller equipped with a cylinder made of metal whose surface has been subjected to plate-making. In the spray system, a paper treatment agent is sprayed onto paper in the form of a mist from a nozzle by compressed air. In the rotor dampening system, a paper treatment agent is sprayed onto paper in the form of a mist using a disk rotating at high speed.

[0094] The amount of paper treatment agent to be coated onto paper is not particularly limited but the amount in terms of weight of the paper treatment agent is preferably 1 to 12 g / m2, more preferably 1.7 to 10 g / m2.(Method for Improving Paper Texture)

[0095] The method for improving paper texture according to the present invention is directed to a method of treating paper with the paper treatment agent as explained above. Specific embodiments for treating paper with the paper treatment agent are as explained above. The treatment of paper with the paper treatment agent of the present invention allows the paper to have a smooth and sleek feel that is unique to and exhibited by gel, thus improving the texture.EXAMPLES

[0096] The present invention will be described in greater detail hereunder with reference to working examples. However, the invention shall not be limited to the following working examples.(1) Preparation of Paper Treatment Agent

[0097] The following processes were used to prepare the paper treatment agent.

[0098] The respective ingredients of the additive amounts as shown in Tables 1A to 1D were put into a beaker, and the ingredients were mixed and stirred at a temperature by which the respective ingredients were dissolved to prepare the paper treatment agent. The amounts of the respective ingredients shown in Tables 1A to 1D indicate the effective amounts excluding water if the actual amount includes water. The amount of water in the actual amount is included in the amount of added water indicated in the tables.(2) Preparation of Coated Paper

[0099] The paper treatment agent obtained by the above method was uniformly applied to both sides of dry tissue (ply number 2, basis weight 12 to 14 g / m2) so that the mass of the paper treatment agent was 25% by mass±3% by mass relative to the mass of the base paper, and then air-dried for 3 hours.(3) Evaluation

[0100] The following evaluations were performed on the paper treatment agents and the coated papers of the working and comparative examples which were prepared in the manner as shown above.[Smooth and Sleek Feel that is Unique to the Gel (Sensory Evaluation)]

[0101] The coated papers prepared by the process (2) explained above were evaluated for sensory evaluation by 10 experienced panel members on a scale of 1 to 3 based on the following evaluation scores, and their average scores were used to evaluate a smooth and sleek feel that is unique to the gel using the following criteria.Evaluation Score:Score 3: Smooth and sleek feel unique to gel was felt

[0103] Score 2: Smooth and sleek feel unique to gel was slightly felt

[0104] Score 1: Smooth and sleek feel unique to gel was not feltEvaluation Criteria:⊚++: Average score of 10 panel members was 2.7 or more

[0106] ⊚+: Average score of 10 panel members was from 2.3 to less than 2.7

[0107] ⊚: Average score of 10 panel members was from 2.0 to less than 2.3

[0108] ∘: Average score of 10 panel members was from 1.8 to less than 2.0

[0109] Δ: Average score of 10 panel members was from 1.5 to less than 1.8

[0110] x: Average score of 10 panel members was less than 1.5[Smooth and Sleek Feel Unique to Gel (Tan δ Value)]

[0111] To simulate the treatment agent on coated paper, the water content of the treatment agent on the coated paper was calculated using the following formula. A treatment agent with the calculated water content was then prepared accordingly.Water⁢ content⁢ of⁢ treatment⁢ agent⁢ on⁢ coated⁢ paper⁢ (%⁢ by⁢ mass)=(Amount⁢ of⁢ water⁢ originating⁢ from⁢ treatment⁢ agent) / ⁢
{(Amount⁢ of⁢ water⁢ originating⁢ from⁢ treatment⁢ agent)+(Amount⁢ of⁢ adhering⁢ material)}

[0112] The amount of water on the coated paper originating from the treatment agent was measured based on the assessment of moisture contents of the uncoated paper and coated paper described in “moisture contents of the coated paper” and calculated using the following formula:Amount⁢ of⁢ water⁢ originating⁢ from⁢ treatment⁢ agent⁢ (%⁢ by⁢ mass)=(Amount⁢ of⁢ water⁢ in⁢ coated⁢ paper)-
(Amount⁢ of⁢ water⁢ in⁢ uncoated⁢ paper).

[0113] The amount of adhering material was determined by measuring the amount of extract material by performing Soxhlet extraction of the coated paper, and calculated based on the following formula:Amount⁢ of⁢ adhering⁢ material⁢ (%⁢ by⁢ mass)=[(Mass⁢ of⁢ extract⁢ material) / 
{(Mass⁢ of⁢ test⁢ paper)-(Mass⁢ of⁢ extract⁢ material)]}×100

[0114] A rheometer MCR102 (manufactured by Anton Paar) was used as the testing equipment to perform strain dispersion measurements (temperature 25° C., frequency 1 Hz) of the samples prepared above from which the loss modulus and storage modulus at a strain of 1% were measured, and the loss tangent was calculated based on the formula defined as:Loss⁢ tangent⁢ (tan⁢ δ⁢ value)=Loss⁢ modulus⁢ (G′) / Storage⁢ modulus⁢ (G″)

[0115] A larger tan δ value indicates a more viscous material (liquid-like properties), while a smaller tan δ value indicates a more elastic material (solid-like properties). As the tan δ value correlates to the smooth and sleek feel that is unique to the gel, a smaller tan δ value indicates more smooth texture. However, when the value exceeds a certain threshold, it imparts solid-like physical properties, causing the coated paper to be rigid and resulting in a deterioration in texture.

[0116] It is preferred in terms of forming a gel with suitable firmness that the tan δ value be 10,000 or lower, more preferably 100 or lower, even more preferably 50 or lower, and still more preferably 1 or lower. It is also preferred in terms of forming a gel with suitable softness that the tan δ value be 0.01 or higher, more preferably 0.1 or higher. It is preferred that the value be 0.1 to 10,000, more preferably 0.1 to 100.

[0117] The results of Tables 1A to 1D demonstrate a correlation between the tan δ and the “smooth and sleek feel that is unique to the gel” in the sensory evaluation.

[0118] The evaluations were made on the difference between the “smooth and sleek feel that is unique to the gel” as explained above and the normal “sleek feel” in a manner as explained below. The “Smooth and sleek feel unique to gel” of the former one was compared with the “sleek feel” of the latter one with respect to Working Example 5, Working Example 3, Comparative Example 1, and Comparative Example 2 in Table 1, based on the criteria outlined below.[Sleek Feel (Sensory Evaluation)]

[0119] The coated papers prepared by the process (2) explained above were evaluated for sensory evaluation by 10 experienced panel members on a scale of 1 to 3 based on the following evaluation scores, and their average scores were used to evaluate the sleek feel using the following criteria.Evaluation Score:Score 3: Sleek feel was felt

[0121] Score 2: Sleek feel was slightly felt

[0122] Score 1: Sleek feel was not feltEvaluation Criteria:⊚: Average score of 10 panel members was 2.5 or more

[0124] ∘: Average score of 10 panel members was from 1.5 to less than 2.5

[0125] x: Average score of 10 panel members was less than 1.5

[0126] The results of the above evaluations are as shown in Table 2. The results of the “sleek feel” of Working Example 5, Working Example 3, Comparative Example 1, and Comparative Example 2 are indicated in parallel with the results on the “smooth and sleek feel that is unique to the gel” and tan δ of Table 1. As shown, no significant difference was observed in the “sleek feel” among Working Example 5, Working Example 3, and Comparative Examples 1 and 2, while significant differences were observed in the “smooth and sleek feel that is unique to the gel”.[Moist Feeling (Sensory Evaluation)]

[0127] The coated papers prepared by the process (2) explained above were evaluated for sensory evaluation by 10 experienced panel members on a scale of 1 to 3 based on the following evaluation scores, and their average scores were used to evaluate the moist feeling using the following criteria.Evaluation Score:Score 3: Moist feeling was felt

[0129] Score 2: Moist feeling was slightly felt

[0130] Score 1: Moist feeling was not feltEvaluation Criteria:⊚+: Average score of 10 panel members was 2.5 or more

[0132] ⊚: Average score of 10 panel members was from 2.0 to less than 2.5

[0133] ∘: Average score of 10 panel members was from 1.5 to less than 2.0

[0134] x: Average score of 10 panel members was less than 1.5[Water Content in Coated Paper]

[0135] The coated papers were prepared by applying the treatment agent thereto in an amount of 25% by mass relative to the mass of dried tissue. Water contents of the coated papers were determined based on the masses of five pairs (ten sheets) of samples left to stand for 24 hours at the temperature of 25° C. and the humidity of 40%. The samples after the measurement were dried until they reached constant weights in a dryer at 80° C. and the masses of the bone-dry papers were measured from which the moisture content was calculated using the following formula:Moisture⁢ content⁢ (%⁢ by⁢ mass)={(Mass⁢ of⁢ moisture-conditioned⁢ paper)-(Mass⁢ of⁢ bone-dry⁢ paper)] / ⁢
(Mass⁢ of⁢ bone-dry⁢ paper)×100[Viscosity of Paper Treatment Agent]

[0136] The B-type viscometer was used to measure the viscosity at 60 rpm and 40° C. of the paper treatment agent, prepared by the process (1) as shown above, and the viscosity was evaluated using the following criteria.Evaluation Criteria:∘: The paper treatment agent had a viscosity of less than 500 mPa s

[0138] Δ: The paper treatment agent had a viscosity from 500 mPa s to less than 2000 mPa s

[0139] x: The paper treatment agent had a viscosity of 2000 mPa s or more, or was unmeasurable (could not maintain a uniform state)

[0140] The formulations of the working and comparative examples and the evaluation results of respective items are as shown in Tables 1A to 1D. In Tables 1A to 1D, the formulation amounts of the respective components are shown in terms of parts by mass.

[0141] The grades of ∘, ⊚, ⊚+, and ⊚++, as indicated in the respective items in Tables 1A to 1D for evaluating the smooth and sleek feel that is unique to the gel (Sensory evaluation), are regarded as favorable and denote progressively better solutions in this sequence to the object of the invention. In addition, the grades inferior or equivalent to Δ were determined in this evaluation as those incapable of solving the object of the invention. The overall grades of the respective evaluations were also shown in Table 1 by the scales of ⊚+, ⊚, ∘, Δ, and x. The results on difference between the “smooth and sleek feel that is unique to the gel” and “sleek feel” as explained above were shown in Table 2.

[0142] In the tables, the numerals following the letter C in the alkyl phosphate ester salt or polyoxyalkylene alkyl ether phosphate ester salt (B) represent the number of carbon atoms in alkyl group.TABLE 1AWorking example12345678910PolyhydricGlycerin17.0042.5068.0076.5080.7582.4584.1584.4584.5084.83alcoholSorbitol1,3-ButanediolAlkyl phosphateAlkyl phosphate ester salt (C4)ester salt orAlkyl phosphate ester salt (C6)polyoxyalkyleneAlkyl phosphate ester salt (C8)alkyl etherAlkyl phosphate ester salt (C12)phosphate esterAlkyl phosphate ester salt (C14)68.0042.5017.008.504.252.550.850.550.500.17saltAlkyl phosphate ester salt (C16)Alkyl phosphate ester salt (C18)Alkyl phosphate ester salt (C24)Alkyl phosphate ester salt (C26)Alkyl phosphate ester salt (C28)Alkyl phosphate ester salt (C30)Alkyl phosphate ester salt (C14) EO adductAlkyl phosphate ester salt (C16) EO adductAlkyl phosphate ester salt (C18) EO adductWater15.0015.0015.0015.0015.0015.0015.0015.0015.0015.00Nonionic surfactantEmulsifier-type cosmetic productAntifoam agent (silicone emulsion)Liquid paraffinTotal100.00100.00100.00100.00100.00100.00100.00100.00100.00100.00EvaluationSmooth and sleek feel unique ⊚−−⊚++⊚+−⊚+⊚−⊚+⊚−⊚+⊚⊚to gel (Sensory evaluation)Loss tangent (tan δ value)0.400.600.801.504.507.0020.0025.0085.0095.00Moist feeling (Sensory evaluation)◯◯⊚⊚+⊚−⊚◯◯◯◯Water content in coated 5.505.606.006.206.256.055.655.555.525.5paper (% by mass)Viscosity of paper treatment agentΔΔΔ◯◯◯◯◯◯◯Comprehensive evaluation result◯◯◯⊚+⊚−⊚⊚⊚◯◯TABLE 1BWorking example11121314151617181920PolyhydricGlycerin84.9255.0080.7580.7580.7580.7580.7580.7580.7580.75alcoholSorbitol1,3-Butanediol20.00Alkyl phosphateAlkyl phosphate ester salt (C4)ester salt orAlkyl phosphate ester salt (C6)4.25polyoxyalkyleneAlkyl phosphate ester salt (C8)4.25alkyl etherAlkyl phosphate ester salt (C12)4.25phosphate esterAlkyl phosphate ester salt (C14)0.0910.00saltAlkyl phosphate ester salt (C16)4.25Alkyl phosphate ester salt (C18)4.25Alkyl phosphate ester salt (C24)4.25Alkyl phosphate ester salt (C26)4.25Alkyl phosphate ester salt (C28)4.25Alkyl phosphate ester salt (C30)Alkyl phosphate ester salt (C14) EO adductAlkyl phosphate ester salt (C16) EO adductAlkyl phosphate ester salt (C18) EO adductWater15.0015.0015.0015.0015.0015.0015.0015.0015.0015.00Nonionic surfactantEmulsifier-type cosmetic productAntifoam agent (silicone emulsion)Liquid paraffinTotal100.00100.00100.00100.00100.00100.00100.00100.00100.00100.00EvaluationSmooth and sleek ◯⊚+◯⊚+⊚−⊚+⊚+⊚◯◯feel unique to gel(Sensory evaluation)Loss tangent (tan δ value)1450.001.201100.007.005.004.004.003.000.100.08Moist feeling ◯⊚⊚⊚+⊚−⊚+⊚+⊚+⊚+⊚+(Sensory evaluation)Water content in coated 5.506.005.956.256.156.106.256.256.256.20paper (% by mass)Viscosity of paper ◯◯◯◯◯◯◯◯◯Δtreatment agentComprehensive ◯⊚◯⊚+⊚−⊚+⊚+⊚⊚◯evaluation resultTABLE 1CWorking example21222324252627282930PolyhydricGlycerin80.7580.7580.7583.7573.7560.7556.7578.7578.7578.75alcoholSorbitol1,3-ButanediolAlkyl phosphateAlkyl phosphate ester salt (C4)ester salt orAlkyl phosphate ester salt (C6)polyoxyalkyleneAlkyl phosphate ester salt (C8)alkyl etherAlkyl phosphate ester salt (C12)phosphate esterAlkyl phosphate ester salt (C14)4.254.254.254.254.254.254.25saltAlkyl phosphate ester salt (C16)Alkyl phosphate ester salt (C18)Alkyl phosphate ester salt (C24)Alkyl phosphate ester salt (C26)Alkyl phosphate ester salt (C28)Alkyl phosphate ester salt (C30)Alkyl phosphate ester salt 4.25(C14) EO adductAlkyl phosphate ester salt 4.25(C16) EO adductAlkyl phosphate ester salt 4.25(C18) EO adductWater15.0015.0015.0012.0022.0035.0039.0015.0015.0015.00Nonionic surfactant2.00Emulsifier-type cosmetic productAntifoam agent 2.00(silicone emulsion)Liquid paraffin2.00Total100.00100.00100.00100.00100.00100.00100.00100.00100.00100.00EvaluationSmooth and sleek ⊚+⊚−⊚+⊚+⊚+⊚+◯⊚−⊚+⊚+feel unique to gel(Sensory evaluation)Loss tangent (tan δ value)4.003.503.508.003.002.009000.003.503.006.00Moist feeling ⊚+⊚−⊚+⊚+⊚+⊚◯⊚−⊚+⊚+(Sensory evaluation)Water content in coated 6.306.256.306.156.306.055.606.206.206.25paper (% by mass)Viscosity of paper ◯◯◯◯◯◯◯◯◯◯treatment agentComprehensive ⊚+⊚−⊚+⊚+⊚+⊚⊚⊚−⊚+⊚+evaluation resultTABLE 1DComparative example12345678PolyhydricGlycerin80.7580.7545.0055.0050.0075.0096.00alcoholSorbitol1.001,3-ButanediolAlkyl phosphateAlkyl phosphate ester salt (C4)4.25ester salt orAlkyl phosphate ester salt (C6)polyoxyalkyleneAlkyl phosphate ester salt (C8)alkyl etherAlkyl phosphate ester salt (C12)phosphate esterAlkyl phosphate ester salt (C14)88.0045.005.005.002.50saltAlkyl phosphate ester salt (C16)3.00Alkyl phosphate ester salt (C18)Alkyl phosphate ester salt (C24)Alkyl phosphate ester salt (C26)Alkyl phosphate ester salt (C28)Alkyl phosphate ester salt (C30)4.25Alkyl phosphate ester salt (C14) EO adductAlkyl phosphate ester salt (C16) EO adductAlkyl phosphate ester salt (C18) EO adductWater12.0015.0015.0010.0040.0040.0010.00Nonionic surfactant5.001.00Emulsifier-type cosmetic product10.00Antifoam agent (silicone emulsion)Liquid paraffin1.50Total100.00100.00100.00100.00100.00100.00100.00100.00EvaluationSmooth and sleek feel unique to gelXΔΔΔΔΔΔX(Sensory evaluation)Loss tangent (tan δ value)0.005101000.0090.0091060011000104000.008Moist feeling (Sensory evaluation)X◯◯ΔΔΔ⊚+XWater content in coated paper (% by mass)5.405.805.805.445.425.426.255.40Viscosity of paper treatment agentX◯ΔΔ◯◯ΔXComprehensive evaluation resultXΔΔXΔΔΔXTABLE 2Smooth and sleekSleektan δfeel unique to gelfeelvalueWorking example 5⊚+⊚4.5Working example 3⊚++⊚0.8Comparative example 1X◯0.005Comparative example 2Δ⊚101000

Claims

1. A paper treatment agent comprising:(A) a polyhydric alcohol;(B) at least one selected from an alkyl phosphate ester salt and a polyoxyalkylene alkyl ether phosphate ester salt with each alkyl group having 6 to 28 carbon atoms; and(C) water,wherein the water (C) is contained therein in an amount greater than 10% by mass and less than 40% by mass.

2. The paper treatment agent according to claim 1, wherein the paper treatment agent forms gel on a paper treated therewith.

3. The paper treatment agent according to claim 1, wherein the paper treatment agent contains substantially no emulsified cosmetic product.

4. The paper treatment agent according to claim 1, wherein the component (B) is contained in an amount higher than 0.5% by mass.

5. A paper treated with the paper treatment agent according to claim 1.

6. A method for improving paper texture comprising treating paper with the paper treatment agent according to claim 1.

7. A method for producing the paper treatment agent according to claim 1, comprising a step of adding the components (A) to (C).

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