JP2024118161A - Paper products - Google Patents

Abstract

[Problem] To provide a paper product that has a cloth-like appearance (good drape) and cloth-like feel (good softness, smoothness, skin-friendly feel, and moist feel). [Solution] The paper product according to one embodiment of the present invention is made by impregnating a base paper containing wood fiber with a chemical solution, the chemical solution containing a moisturizing component and water, and has a drape coefficient of 76% or less. [Selected Figure] Figure 1

Description

The present invention relates to paper products used for sanitary and household purposes, such as tissue paper, toilet paper, towel paper, and tablecloth paper.

Paper products, particularly tissue paper and toilet paper, come in a wide variety of elaborate designs for storage containers such as outer boxes and wrapping. There are also paper products where the paper itself is printed with pictures or shapes or is brightly colored, and there is demand for these products not only for their functionality as paper but also as interior décor. In this way, paper products come in a wide variety of designs.

On the other hand, fabric products such as woven fabrics, knitted fabrics, and nonwoven fabrics form beautiful and complex patterns with many curves and folds. One method for evaluating the texture of such fabrics is the drape test. Drape is the deformation phenomenon in which fabric hangs down under its own weight, and the smaller the drape coefficient in the drape test, the more easily the fabric hangs down, and the softer and more elegant the impression it gives.

Thus, the drape coefficient has traditionally been used to evaluate the feel of fabric products such as woven fabrics, knitted fabrics, and nonwoven fabrics, but this has not been common for paper products used for sanitary or household purposes, such as tissue paper, toilet paper, towel paper, and tablecloth paper.

For example, Patent Document 1 describes the drapeability of nonwoven fabric products.

Patent Document 2 describes a sanitary product that features a nonwoven dry sheet made of spunlace nonwoven fabric that can be taken out like a tissue box using a pop-up system. It also describes that nonwoven fabrics such as spunlace nonwoven fabric are strong, soft, and have a good texture, so they have good drape properties and can be used in a wide range of situations.

Patent Document 3 describes the drapeability of fiber web products such as tissue paper, but does not disclose the drape coefficient measured by a drapeability test. Furthermore, the drapeability in Patent Document 3 relates to the balance between thickness and softness, and there is no mention of the effect of drapeability on the appearance of paper products.

Patent Document 4 discloses crepe paper that contains moisturizing ingredients, water, oily ingredients, and vegetable powder, but does not provide any evaluation or findings regarding drapeability, etc.

JP 2007-270364 A JP 2022-65416 A JP 2011-74518 A Patent No. 7036307

Although there are paper products with excellent functionality such as texture and wiping ability, there has been no evaluation of their cloth-like appearance or feel. Therefore, there is a demand to establish a method for measuring the drapeability of paper products and provide paper products that have a cloth-like appearance (good drape) and cloth-like feel (good softness, smoothness, feel that conforms to the skin, and moist feel).

One aspect of the paper product according to the present invention is
A paper product in which a base paper containing wood fibers is impregnated with a chemical solution,
The drug solution contains a moisturizing component and water,
The drape coefficient is 76% or less.

In one embodiment of the paper product,
The impregnation amount of the chemical solution may be 10 to 40% by mass based on the total mass of the base paper.

In any of the embodiments of the paper product described above,
the wood fibers include hardwood pulp;
The hardwood pulp content may be 40 mass% or more based on the total mass of the wood fibers.

In any of the embodiments of the paper product described above,
The drug solution may further contain an oily component.

In any of the embodiments of the paper product described above,
The moisturizing ingredient includes glycerin,
The glycerin content may be 5% by mass or more based on the total mass of the base paper.

In any of the embodiments of the paper product described above,
The base paper may have 2 to 3 plies.

In any of the embodiments of the paper product described above,
The surface of the paper product may have a mean deviation (MMD) of the coefficient of friction in the papermaking direction as measured by the KES method of 0.0075 or less.

In any of the embodiments of the paper product described above,
The ratio MIU/MMD of the average coefficient of friction (MIU) in the papermaking direction on the surface of the paper product as determined by the KES method to the mean deviation (MMD) of the coefficient of friction (MMD) in the papermaking direction on the surface of the paper product as determined by the KES method may be 25 or more.

In any of the embodiments of the paper product described above,
The tensile strength of the paper product in the papermaking direction when dry is 1.8 N or more;
The paper product may have a tensile strength of 0.6 N or more in a direction perpendicular to the paper-making direction when dry.

In any of the embodiments of the paper product described above,
Where a thickness T0 is measured at a pressure of 0.5 gf/ ^cm2 in a compression test by the KES method and a thickness TM is measured at a pressure of 50.0 gf/ ^cm2 in a compression test by the KES method, T0-TM may be 0.100 mm or more.

FIG. 2 is a side view of an apparatus for measuring the drape coefficient of a paper product according to one embodiment of the present invention. FIG. 2 is a plan view of the sample stage and its surroundings of an apparatus for measuring the drape coefficient of a paper product according to one embodiment of the present invention.

The following describes an embodiment of the present invention. The embodiment described below is an example of the present invention. The present invention is not limited to the following embodiment, and includes various modified forms that are implemented within the scope that does not change the gist of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

1. Paper Product The paper product according to one embodiment of the present invention is a paper product in which a base paper containing wood fibers is impregnated with a chemical solution, the chemical solution containing a moisturizing component and water, and the drape coefficient is 76% or less.

Conventionally, the JIS L1096 G method has been commonly used for the drapeability test, with a circular sample stand measuring 12.7 cm in diameter and a circular sample piece measuring 25.4 cm in diameter. However, when attempting to measure paper products such as tissue paper using this method, it is difficult to obtain samples without wrinkles or creases, and it is also difficult to collect the samples themselves. In addition, because paper products are lighter per unit area than cloth products, measurement errors are more likely to occur. For this reason, although there are paper products that have excellent functionality such as feel and wiping ability, they have not been evaluated for their appearance or feel like cloth.

Drapability is affected by the stiffness and weight of the paper product, so for example, changes in the chemical solution components or amount that affect the cloth-like feel can also affect drapeability. Therefore, in the past, when drapeability tests for paper products had not been established, it was difficult to achieve both a cloth-like appearance and a cloth-like feel.

The inventors have now developed a method that allows for satisfactory drapeability testing of paper products. This method allows for direct evaluation of the drapeability of paper products and allows for accurate calculation of the drape coefficient. Therefore, according to the present invention, it is now possible to provide a paper product that has a cloth-like appearance (good drape) and a cloth-like feel (good softness, smoothness, skin-friendly feel, and moist feel) when it contains specific components and has a drape coefficient below a specific value as measured by the newly developed method.

1.1 Physical properties of paper products Physical properties were measured for each number of plies of the paper product. For example, if the paper product was a two-ply product, the measurements were performed for two plies, and if the paper product was a three-ply product, the measurements were performed for three plies.
1.1.1 Drape Coefficient The paper product according to this embodiment has a drape coefficient of 76% or less.

The inventors have now developed a method that allows for satisfactory drapeability testing of paper products. Figure 1 is a side view of an apparatus 1 for measuring the drape coefficient of a paper product according to one embodiment of the present invention, and Figure 2 is a plan view of the sample stage 2 and its surroundings of the apparatus 1 for measuring the drape coefficient of a paper product according to one embodiment of the present invention. As shown in Figure 1, the apparatus 1 comprises the sample stage 2, a weight 22, a motor 23, a camera 3, and a stand 31.

The measurement procedure can be carried out as described in the examples below.

The drape coefficient of the paper product according to this embodiment is 76% or less, preferably 73% or less, more preferably 70% or less, even more preferably 67% or less, and particularly preferably 64% or less. When the drape coefficient is within the above range, a better drape feeling is obtained, and a better cloth-like appearance and cloth-like feel tend to be obtained.

1.1.2 Friction characteristics The paper product according to this embodiment has a mean deviation (MMD) of the friction coefficient measured by the KES method in the papermaking direction on the surface of the paper product of 0.0075 or less, more preferably 0.0065 or less, even more preferably 0.0060 or less, and particularly preferably 0.0055 or less. If the mean deviation (MMD) of the friction coefficient is within the above range, a better cloth-like appearance and cloth-like feel tend to be obtained. The mean deviation (MMD) of the friction coefficient indicates the smoothness of the sample surface, and the smaller the value, the smoother it is.

In this specification, "papermaking direction" refers to the direction in which the paper flows during papermaking. The papermaking direction is also sometimes called the vertical direction, and the direction perpendicular to the papermaking direction is sometimes called the horizontal direction.

The "KES method" is an abbreviation for "KAWABATA EVALUATION SYSTEM" and is one of the methods for measuring and objectively evaluating texture. The mechanical measurements based on the KES method in this specification are explained in detail in "Standardization and Analysis of Texture Evaluation," 2nd Edition (published July 10, 1980 by the Texture Measurement and Standardization Research Committee, Textile Machinery Society of Japan).

In the paper product according to this embodiment, the ratio MIU/MMD of the average coefficient of friction (MIU) in the papermaking direction on the surface of the paper product by the KES method to the average deviation (MMD) of the coefficient of friction in the papermaking direction on the surface of the paper product by the KES method is preferably 25 or more, more preferably 30 or more, and even more preferably 35 or more. When MIU/MMD is within the above range, it tends to be possible to obtain a better cloth-like appearance and cloth-like feel. The average coefficient of friction (MIU) indicates the slipperiness of the sample surface, and the larger the value, the less slippery it is. Also, the larger the MIU/MMD value, the smoother but less slippery the surface is.

The mean deviation (MMD) and mean coefficient of friction (MIU) of friction can be measured, for example, using a friction tester "KES-SE4" (manufactured by Kato Tech Co., Ltd.). Specifically, this can be done as described in the examples below.

1.1.3 Tensile properties The paper product according to this embodiment preferably has a tensile strength in the papermaking direction when the paper product is dry of 1.8 N or more, and a tensile strength in the direction perpendicular to the papermaking direction when the paper product is dry of 0.6 N or more. If the tensile strength is within the above range, a better cloth-like appearance and cloth-like feel tend to be obtained.

The tensile strength in the papermaking direction when the paper product is dried is preferably 1.9 N or more, and more preferably 2.0 N or more. The upper limit of the tensile strength is preferably 3.0 N or less, more preferably 2.7 N or less, and even more preferably 2.4 N or less. If the tensile strength is within the above range, it tends to be possible to obtain a better cloth-like appearance and cloth-like feel.

The tensile strength of the paper product in the direction perpendicular to the papermaking direction during drying is preferably 0.7 N or more, and more preferably 0.8 N or more. The upper limit of the tensile strength is preferably 1.5 N or less, and more preferably 1.3 N or less. If the tensile strength is within the above range, a better cloth-like appearance and cloth-like feel tend to be obtained.

The tensile strength in the present invention can be measured as described in the Examples below.

1.1.4 Compression properties In the paper product according to this embodiment, where the thickness T0 is measured in a compression test using the KES method at a pressure of 0.5 gf/ ^cm2 and the thickness TM is measured in a compression test using the KES method at a pressure of 50.0 gf/ ^cm2 , it is preferable that T0 - TM is 0.100 mm or more, and more preferably 0.120 mm or more. If T0 - TM is in the above range, it tends to be possible to obtain a better cloth-like appearance and cloth-like feel.

In the present invention, the thickness T0 at a pressure of 0.5 gf/ ^cm2 and the thickness TM at a pressure of 50.0 gf/ ^cm2 can be measured, for example, using a compression tester "KES-FB3" (manufactured by Kato Tech Co., Ltd.). Specifically, they can be measured as described in the examples below.

As described above, it is preferable to set the drape coefficient, which evaluates the cloth-like drooping appearance, the tensile strength, the mean deviation of the coefficient of friction (MMD), which evaluates the surface smoothness, the (MIU/MMD) value, which evaluates the feel that is smooth against the skin, and the T0-TM value, which represents the plump feel, within specific ranges. This tends to result in a paper product that has a cloth-like appearance, excellent cloth-like feel such as smoothness and softness, and sufficient strength.

Below, we will explain each component that makes up the paper product according to this embodiment.

1.2 Base Paper The paper product according to this embodiment uses dry crepe paper containing wood fibers as the base paper.

The fiber components of the base paper need to contain at least wood fibers, but may also contain non-wood plant fibers. The fiber components are preferably plasticized by moisture. Examples of wood fibers include hardwood pulp and softwood pulp. Examples of non-wood plant fibers include natural fibers other than wood, such as plant fibers such as hemp, bast fibers, cotton, and kenaf, and animal fibers such as silk and wool, as well as chemical fibers such as recycled fibers such as rayon and cupra, and synthetic fibers such as acrylic, polyethylene, polyester, polypropylene, and nylon.

The wood fibers contained in the base paper are preferably hardwood pulp or softwood pulp, or both, in a total amount of 80% by mass or more relative to the total mass of the base paper, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more.

In the paper product according to this embodiment, the wood fibers contain hardwood pulp, and the hardwood pulp content is preferably 40% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, based on the total mass of the wood fibers. Since hardwood pulp has shorter and thinner fibers than softwood pulp, when the wood fibers contain hardwood pulp in the above range, a better cloth-like appearance and cloth-like feel tend to be obtained.

In the paper product according to the present embodiment, the wood fibers contain coniferous pulp, and the content of coniferous pulp is preferably 60% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 10% by mass or less, based on the total mass of the wood fibers. The lower limit of the content of coniferous pulp is not particularly limited, but is preferably 3% by mass or more, more preferably 5% by mass or more, based on the total mass of the wood fibers. When the wood fibers contain coniferous pulp in the above range, it is possible to obtain a suitable strength, and thus it is likely to obtain a better cloth-like appearance and cloth-like feel.

The base paper may contain additives such as wet strength agents. Examples of wet strength agents include polyamide epichlorohydrin resin and polyamine epichlorohydrin resin. Commercially available wet strength agents may be used, such as WS4020, WS4030, WS4027, and WS4011 (all of which are product names manufactured by Seiko PCM Corporation). The content of the additives is preferably 0.01 to 0.5% by mass, more preferably 0.05 to 0.4% by mass, and even more preferably 0.1 to 0.3% by mass, based on the total mass of the fiber components.

The form of the base paper is not particularly limited, but it is preferable to use dry crepe paper in which crepe is formed by a doctor blade on the dryer of the papermaking machine during papermaking.

The number of plies of the base paper is preferably 1 to 4, and more preferably 2 to 3. If the number of plies of the base paper is within the above range, a good drape feeling can be obtained, and a better cloth-like appearance and cloth-like feel tend to be obtained. Note that "number of plies" refers to the number of layers of the base paper.

The basis weight of the base paper is preferably 10 to 20 g/m ² , more preferably 13 to 17 g/m ² , and even more preferably 14 to 16 g/m ^2. When the basis weight of the base paper is within the above range, a good drape feeling is obtained, and a better cloth-like appearance and cloth-like feel tend to be obtained.

1.3 Chemical Solution The paper product according to this embodiment is obtained by impregnating the base paper described above with a chemical solution. The chemical solution contains at least a moisturizing component and water.

The amount of the chemical solution impregnated is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 20 to 30% by mass, based on the total mass of the base paper. If the amount of the chemical solution impregnated is within the above range, the drape and feel will be better, and it tends to be possible to obtain a better cloth-like appearance and cloth-like feel.

On the other hand, from the viewpoint of obtaining the effects of the present invention more effectively, the impregnation amount of the chemical solution of the present invention is preferably 10 to 23% by mass, more preferably 12 to 21% by mass, and even more preferably 15 to 20% by mass, relative to the total mass of the base paper. The paper product according to this embodiment is characterized in that the drape coefficient is set to a predetermined value or less. In the present invention, it has been newly discovered that by adjusting the drape coefficient, it is possible to obtain a good cloth-like appearance and cloth-like feel even when the amount of chemical solution impregnated is relatively small.

Below, we will explain each component contained in the chemical solution used in the paper products of this embodiment.

The chemical solution used in the paper product according to this embodiment contains a moisturizing component. The moisturizing component has the effect of absorbing moisture from the atmosphere, increasing the moisture content of the fiber components, promoting plasticization, and softening the fibers.

Examples of the moisturizing component include polyhydric alcohols, sugar alcohols, carbohydrates, amino acids, organic acids, etc. The moisturizing component is preferably at least one selected from polyhydric alcohols, sugar alcohols, carbohydrates, amino acids, and organic acids, and more preferably at least one selected from polyhydric alcohols and sugar alcohols.

Examples of polyhydric alcohols include glycerin, diglycerin, polyglycerin, polyethylene glycol (average molecular weight of 200 or more and less than 1000), propylene glycol, 1,3-butylene glycol, ethylene glycol, diethylene glycol, etc. Among polyhydric alcohols, glycerin is preferred from the viewpoint of superior hygroscopicity.

Examples of sugar alcohols include sorbitol, xylitol, erythritol, mannitol, lactitol, oligosaccharide alcohols, maltitol, reduced starch hydrolysates, etc. Among sugar alcohols, sorbitol is preferred from the viewpoint of superior moisture retention.

Examples of carbohydrates include monosaccharides such as fructose and glucose, disaccharides such as trehalose, and oligosaccharides including trisaccharides such as maltotriose.

Examples of amino acids include glycine betaine and its salts.

Examples of organic acids include pyrrolidone carboxylic acid, lactic acid, and their salts such as sodium salts.

The moisturizing ingredients may be used alone or in combination of two or more.

Among these moisturizing ingredients, it is preferable to include glycerin and sorbitol. Glycerin is highly hygroscopic and therefore suitable as a moisturizing ingredient, and sorbitol has excellent moisture retention properties, so by using it in combination with glycerin, the moisture content becomes more stable against changes in the surrounding environment. This tends to result in a better cloth-like appearance and cloth-like feel.

In the paper product according to this embodiment, the moisturizing component contains glycerin, and the glycerin content is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, relative to the total mass of the base paper. When the content of such moisturizing components is within the above range, there is a tendency for the product to have excellent moisturizing properties and a better cloth-like appearance and feel.

The paper product according to this embodiment contains sorbitol as a moisturizing ingredient, and the sorbitol content is preferably 1:1-10 glycerin, and more preferably 1:5-9 glycerin. When the content of such moisturizing ingredients is within the above range, the moisture content is more stable against changes in the surrounding environment, and a better cloth-like appearance and cloth-like feel tends to be obtained.

The content of the moisturizing ingredient is preferably 10% by mass or more, more preferably 12% by mass or more, even more preferably 14% by mass or more, particularly preferably 16% by mass or more, and even more particularly preferably 18% by mass or more, relative to the total mass of the base paper. The upper limit of the content of the moisturizing ingredient is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, relative to the total mass of the base paper. When the content of the moisturizing ingredient is within the above range, a better cloth-like appearance and cloth-like feel tend to be obtained.

1.3.2 Water Water can be contained in the chemical solution used in the paper product according to this embodiment.
The moisture in the paper product is maintained by the moisture-retaining component absorbing moisture from the atmosphere in the environment in which the paper product is used. Therefore, it is preferable to incorporate moisture absorbed from the atmosphere into the chemical solution in advance together with the moisture-retaining component, and pure water such as ion-exchanged water or distilled water is preferably used.

The water content in a paper product varies depending on the moisturizing component, so the increase in moisture content under standard conditions (temperature 23±1°C, relative humidity 50±2%) is preferably 1% by mass or more of the total mass of the base paper, more preferably 2% by mass or more, even more preferably 3% by mass or more, particularly preferably 4% by mass or more, and even more particularly preferably 5% by mass or more. If the water content is within the above range, it tends to be possible to obtain a better cloth-like appearance and cloth-like feel.

1.3.3 Oil-based component The chemical solution used in the paper product according to this embodiment may contain an oil-based component. The oil-based component has the function of smoothing the surface of the base paper and transferring to the skin to give a smooth feel. When the chemical solution contains an oil-based component, it tends to give a more cloth-like feel to the skin.

Examples of oily components include hydrocarbons, vegetable oils, fatty acids, waxes, higher alcohols, esters, etc. Among these, the oily components are preferably hydrocarbons and vegetable oils, more preferably saturated hydrocarbons that are less susceptible to oxidation, and even more preferably hydrocarbons that are liquid at 23°C.

Examples of hydrocarbons include liquid paraffin, solid paraffin, and squalane, with liquid paraffin being more preferred. The pour point of the hydrocarbons is preferably 0°C or lower, more preferably -5°C or lower, and even more preferably -10°C or lower. Here, the pour point in this specification means the pour point defined in JIS K2269.

Examples of vegetable oils include olive oil, camellia oil, castor oil, soybean oil, etc.

Examples of fatty acids include stearic acid, palmitic acid, myristic acid, and lauric acid.

Examples of waxes include beeswax, carnauba wax, and lanolin.

Examples of higher alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, and oleyl alcohol.

Examples of esters include isopropyl myristate and isopropyl palmitate.

The oily components may be used alone or in combination of two or more.

When an oily component is contained, the content is preferably 0.5% by mass or more, more preferably 0.7% by mass or more, even more preferably 1.0% by mass or more, and particularly preferably 1.2% by mass or more, relative to the total mass of the base paper. There is no particular upper limit to the content of the oily component, but it is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, relative to the total mass of the base paper. If the content of the oily component is within the above range, it tends to be possible to obtain a better cloth-like feel.

1.3.4 Surfactant The oily components described above are preferably blended in the drug solution as an emulsion in which they are dispersed in the form of fine particles. The emulsion is preferably stabilized using a surfactant.

As the surfactant, nonionic surfactants such as sucrose fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, etc.; anionic surfactants such as fatty acid salts, alkylbenzene sulfonates, polyoxyethylene alkyl ether sulfates, etc.; etc. are preferably used. As the surfactant, nonionic surfactants are more preferred, and polyoxyethylene sorbitan fatty acid esters and sorbitan fatty acid esters are even more preferred.

1.3.5 Powder The chemical solution used in the paper product according to this embodiment may contain powder. The powder has the effect of improving the softness, smoothness, and cloth-like feel of the paper product, such as a feel that fits the skin. There is no particular limit to the powder, but a vegetable powder that has a high affinity for moisture is preferable.

Examples of plant-derived powders include wood flour, bamboo flour, plant fiber powder, cellulose powder, and starches. The shape of these plant-derived powders is preferably spherical or polyhedral, and starches are particularly preferred for their ease of availability and safety. As the starches, corn starch, potato starch, rice flour, wheat flour, and the like are preferred, with corn starch being particularly preferred.

From the viewpoint of further improving the cloth-like feel, the volume average particle size of the plant powder is preferably 2 to 50 μm, more preferably 5 to 30 μm, and even more preferably 10 to 20 μm. The volume average particle size is the particle size measured by a particle size distribution measuring device that uses the laser diffraction scattering method.

When powder is included, the content is preferably 0.5 to 3.0% by mass, more preferably 0.7 to 2.5% by mass, and even more preferably 1.0 to 2.0% by mass, based on the total mass of the base paper.

On the other hand, from the viewpoint of obtaining the effects of the present invention more effectively, the chemical solution used in the paper product according to this embodiment preferably does not contain powder, more preferably does not contain vegetable powder, and even more preferably does not contain starches. The paper product according to this embodiment is characterized in that the drape coefficient is set to a predetermined value or less. In the present invention, it has been newly discovered that by adjusting the drape coefficient, it is possible to obtain a good cloth-like appearance and cloth-like feel even when the chemical solution does not contain powder (more preferably vegetable powder, and even more preferably starches).

2. Method for Manufacturing Paper Products A method for manufacturing a paper product according to one embodiment of the present invention is a method for manufacturing the above-mentioned paper product, and includes a chemical solution blending step of preparing the above-mentioned chemical solution containing a moisturizing component and water, and a chemical solution impregnation step of impregnating the above-mentioned base paper containing wood fibers with the chemical solution.

The manufacturing method according to this embodiment can provide a paper product that has a cloth-like appearance (good drape) and a cloth-like feel (good softness, smoothness, skin-friendly feel, and moist feel).

2.1 Chemical Solution Preparation Step The manufacturing method according to this embodiment includes a chemical solution preparation step of preparing the above-mentioned chemical solution containing a moisturizing component and water.

The medicinal liquid is prepared by mixing the above-mentioned components in any order. The preferred method for mixing the components is to add the materials sequentially to a container equipped with a stirrer and stir and mix them. When adding an oily component, it is preferable to add a surfactant as necessary to emulsify it with the liquid. When adding a powder, it is preferable to disperse it in the medicinal liquid.

2.2 Chemical Solution Impregnation Step The manufacturing method according to this embodiment includes a chemical solution impregnation step of impregnating the base paper containing wood fibers with the above-mentioned chemical solution.

Methods for impregnating the chemicals include, for example, spraying with a sprayer or coating with a roll. In this case, it is preferable that the chemicals are sprayed or coated on the side that comes into contact with the metal surface of the dryer of the papermaking machine when the base paper is made. This side is called the front side of the base paper, and has a smoother surface than the opposite back side.

3. Examples The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following, "%" is based on mass unless otherwise specified.

3.1 Preparation of paper products Unbeaten NBKP (softwood kraft bleached pulp: weight-weighted average fiber length 2.4-2.6 mm, fiber coarseness 0.148 mg/m) pulp slurry was beaten to a Canadian standard freeness down range of 40-60 ml. Also, LBKP (hardwood kraft bleached pulp: weight-weighted average fiber length 0.60-0.72 mm, fiber coarseness 0.057 mg/m) pulp slurry was beaten to a Canadian standard freeness down range of 30-40 ml.

Pulp was then mixed to obtain the fiber component (pulp) blend ratios shown in Tables 1 and 2 below, and a wet strength agent was added in an amount of 0.2% by mass (solids content per pulp). Dry crepe paper was then made using a papermaking machine in a conventional manner. The resulting crepe paper had a basis weight of 15 g/ ^m2 and a crepe ratio of 24%, and was wound into a roll.

Next, the chemical solution obtained by mixing the components shown in Tables 1 and 2 below was continuously sprayed from both sides of the base paper, which was layered in the specified number of plies, so as to achieve the chemical solution impregnation rate shown in Tables 1 and 2 below, and then rewound into a roll. The rolled crepe paper was then left to stand at room temperature for 24 hours or more, allowing the entire base paper to be uniformly impregnated with the chemical solution.

Then, the base paper was cut into pieces measuring 200 mm vertically (in the papermaking direction) and 225 mm horizontally (in the papermaking width direction) so that the dryer surface of the crepe paper was the front of the paper product, to prepare a large number of samples. Each sample was then left to stand for 24 hours or more in an environment with a temperature of 23±1°C and a humidity of 50±2%, to obtain paper products according to each of the examples and comparative examples.

3.2 Evaluation Method The paper products according to each of the Examples and Comparative Examples obtained above were evaluated by carrying out the following sensory tests and physical property tests.

3.2.1 Sensory test <Drape feeling>
Ten monitors visually observed each sample for sagging due to its own weight and evaluated it according to the following criteria.
The scores given by the 10 monitors were totaled and ranked as follows, with "has a cloth-like drape" receiving 2 points, "has a slight drape" receiving 1 point, and "has no drape" receiving 0 points. ◎ is the best, × is the worst, and △ is acceptable.
(Evaluation Criteria)
"16-20 points": ◎
"11-15 points": 〇 "6-10 points": △
"0 to 5 points": ×

<Skin feel>
Ten monitors touched each sample with their hands and evaluated the tactile sensation (softness, smoothness, skin-friendly sensation, moist sensation) according to the following criteria: "Skin-friendly sensation" means that the surface is smooth, resistant to slipping, and clings to the hand.
"Very good" was given 3 points, "good" 2 points, "slightly good" 1 point, and "not good" 0 points, and the scores given by the 10 monitors were totaled to rank them as follows: ◎ was the best, × was the worst, and △ was acceptable.
(Evaluation Criteria)
"26-30 points": ◎
"16-25 points": 〇 "6-15 points": △
"0 to 5 points": ×

3.2.2 Physical property test <Drape test>
The test apparatus of FIG. 1 was used to perform the measurement under the following conditions. As shown in FIG. 2, the sample 21 (circular, diameter 90 mm) was placed on the sample stage 2 (circular, diameter 35 mm) with the measurement surface facing up, and the sample was fixed by a weight 22 (circular, diameter 35 mm, 100 g). The sample stage 2 was then rotated at 100 rpm by the motor 23 for 1 minute, and allowed to stand for 1 minute after the rotation was stopped. The sample 21 was then photographed from directly above by the camera 3 installed at a position 1 m vertically above the sample stage 2 by the stand 31 to obtain an image, and the vertical projection area of the sample 21 was calculated from the image data, and the drape coefficient was calculated by the following formula (1). The measurement was performed five times on each of the front and back of the sample, and the average value was calculated.

D _f = [(A _d - S ₁ )/(S ₂ - S ₁ )] x 100 (1)
( _Df represents the drape coefficient [%], _Ad represents the vertical projection area (drape shape area) of the sample 21 [mm ² ], _S1 represents the area of the sample stage 2 [mm ² ], and _S2 represents the area of sample 21 [mm ² ].)

Tensile strength test
According to JIS S 3104: 1992, the dry tensile strength (N) was measured in the longitudinal direction (the direction of paper flow during papermaking) and transverse directions of the sample. Two or three test pieces were cut to a width of 25.0±0.1 (mm) depending on the number of plies of the sample, and measurements were made with a gripping distance of 100±2 (mm). The measurement was performed 10 times, and the average value was calculated.

Friction Test
Measurements were performed using a friction tester "KES-SE4" (manufactured by Kato Tech Co., Ltd.). The surface of the overlapped sample was traced with a friction probe according to the number of plies so that the surface side of the crepe paper was the surface of the sample, and the friction coefficient (MIU) and the variation of the friction coefficient (MMD) were obtained. The test was performed 10 times in the longitudinal direction of the sample (the direction of paper flow during papermaking) by changing the sample, and the average value was obtained. Note that the smaller the MIU value, the more slippery the surface is, the smaller the MMD value, the smoother the surface is, and the larger the MIU/MMD value, the smoother but less slippery the surface is.

Compression test
The measurements were carried out using a compression tester "KES-FB3" (manufactured by Kato Tech Co., Ltd.). The sample was set between a ² cm2 circular pressure plate and a pressure plate, and the pressure plate was lowered at a speed of 150 sec/mm, and the pressure and sample thickness changes were measured. The thickness T0 of the sample at a load of 0.5 gf/ ^cm2 and the thickness TM of the sample at a load of 50.0 gf/ ^cm2 were measured, and the change in thickness of the sample (T0-TM) was calculated.

3.3 Evaluation Results The evaluation results are shown in Tables 1 and 2. From the results of each of the above tests, the following evaluations can be made.

<Examples 1 to 3, Comparative Examples 3 and 4>
Examples 1 to 3 in Table 1 above and Comparative Examples 3 and 4 in Table 2 above were different only in the pulp composition, and the chemical components and chemical impregnation rates were the same.
According to Examples 1 to 3 and Comparative Examples 3 and 4, by increasing the proportion of hardwood pulp, the drape coefficient decreases, the drapeability increases, the MMD value decreases, and the MIU/MMD value increases. In the sensory test, Examples 1 to 3 were also given higher ratings for drape, softness, smoothness, and skin-friendly feel than Comparative Examples 3 and 4.
It is thought that the higher the hardwood pulp content, the lower the strength and softer the paper becomes, and therefore the more it sags under its own weight, resulting in a lower drape coefficient.
The smoothness is thought to be due to the fact that increasing the proportion of hardwood pulp results in more short, thin pulp fibers, resulting in a smoother paper, which improves the smoothness of the paper surface.

Examples 4 to 6
In Examples 4 to 6, the pulp blend ratio and the chemical components were the same, but the chemical impregnation rate was changed.
By increasing the drug solution impregnation rate, the drape coefficient and MMD values decrease, and the MIU/MMD value increases. In addition, in sensory tests, the evaluations of drape, softness, smoothness, touch along the skin, and moistness tend to increase.
This is because the greater the amount of chemical solution, the greater the relative amount of moisturizing ingredients, so the pulp fibers retain more water and the pulp fibers become plasticized.
Furthermore, the oily components contained in the chemical solution smooth the surface of the pulp fibers and are transferred to the skin, giving it a smooth feel.

<Examples 7, 8, 9, and 10>
In Examples 7 and 8, the pulp blending ratio and the chemical components were the same, but the chemical impregnation rate was changed.
By increasing the wettability, the drape coefficient and MMD values decrease, and the MIU/MMD value increases.
In Examples 9 and 10, the number of plies was three, and the pulp content and the chemical impregnation rate were changed.
The pulp blend ratios in Example 9 were 80% hardwood pulp and 20% softwood pulp, and in Example 10 were 90% hardwood pulp and 10% softwood pulp.
The difference between Example 8 and Example 9 is only the number of plies, but Example 9 has a higher evaluation of drapeability.
The three-ply sample has a heavier weight per unit area than the two-ply sample, and therefore has a higher drapeability, a drape coefficient of 63% or less, and a high evaluation in the sensory test.

Comparative Examples 1 and 2
Comparative Examples 1 and 2 in Table 2 above are crepe papers to which no moisturizing agent was applied.
Even in the case of a sample containing 90% hardwood pulp as in Comparative Example 1, if the sample does not contain a moisturizing component, the drape coefficient becomes large and the sensory evaluation such as the drape feeling becomes low.
In terms of compression characteristics, in Comparative Example 2, when TO-TM was 0.100 mm or less and the sample was hard, the drape coefficient was high and the sensory evaluation was low.

<summary>
The drape coefficient has a large effect on the drape and softness, and the smaller the drape coefficient, the softer the product will be with excellent drape. The drape coefficient is preferably 76% or less, more preferably 70% or less, and even more preferably 65% or less.

In terms of friction characteristics, the smaller the MMD value, the smoother the feel, and it is preferable that the MMD value is 0.0075 or less, more preferably 0.0065 or less, even more preferably 0.0060 or less, and especially preferably 0.0055 or less.

The MIU/MMD value, calculated by dividing MIU, the coefficient of slipperiness, by MMD, the coefficient of smoothness, indicates that the material is smooth and non-slip, and is an index of the texture that feels like it fits snugly against the skin. The MIU/MMD value is preferably 25 or more, more preferably 30 or more, and even more preferably 35 or more.

The tensile strength when dry (horizontal) is preferably 0.6 N or more, more preferably 0.7 N or more, and even more preferably 0.8 N or more. The tensile strength when dry (vertical) is preferably 1.8 N or more, more preferably 1.9 N or more, and even more preferably 2.0 N or more.

It is preferable that the compression characteristic T0-TM is 0.100 mm or more, and more preferably 0.120 mm.

The higher the proportion of hardwood pulp, the lower the drape coefficient and the higher the sensory evaluation of smoothness and softness. It is preferable for the base paper to contain 40% or more hardwood pulp, more preferably 70% or more, even more preferably 80% or more, and most preferably 90% or more.

The number of plies is preferably 2 to 3.

The sample is preferably moisturizing crepe paper coated with a moisturizing agent. It is preferable that the sample contains 5% or more of glycerin as a moisturizing component, more preferably 10% or more, and even more preferably 15% or more.

It is preferable for the medicinal solution to contain moisture and oily ingredients in addition to moisturizing ingredients.

Each embodiment has sufficient strength as a paper product, and can be made into a product with a cloth-like appearance and feel.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes a configuration that is substantially the same as the configuration described in the embodiment, for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect. The present invention also includes a configuration in which non-essential parts of the configuration described in the embodiment are replaced. The present invention also includes a configuration that has the same action and effect as the configuration described in the embodiment, or can achieve the same purpose. The present invention also includes a configuration in which publicly known technology is added to the configuration described in the embodiment.

1...Apparatus, 2...Sample stage, 21...Sample, 22...Weight, 23...Motor, 3...Camera, 31...Stand

Claims (10)

A paper product in which a base paper containing wood fibers is impregnated with a chemical solution,
The drug solution contains a moisturizing component and water,
A paper product having a drape coefficient of 76% or less. The paper product according to claim 1, wherein the amount of the chemical solution impregnated is 10 to 40% by mass relative to the total mass of the base paper. the wood fibers include hardwood pulp;
3. The paper product according to claim 1, wherein the hardwood pulp content is 40% by mass or more based on the total mass of the wood fibers. The paper product according to claim 1 or 2, wherein the chemical solution further contains an oily component. The moisturizing ingredient includes glycerin,
The paper product according to claim 1 or 2, wherein the glycerin content is 5% by mass or more based on the total mass of the base paper. The paper product according to claim 1 or claim 2, in which the number of plies of the base paper is 2 to 3. The paper product according to claim 1 or 2, wherein the mean deviation (MMD) of the coefficient of friction in the papermaking direction on the surface of the paper product according to the KES method is 0.0075 or less. The paper product according to claim 1 or 2, in which the ratio MIU/MMD of the average coefficient of friction (MIU) in the papermaking direction on the surface of the paper product by the KES method and the mean deviation (MMD) of the coefficient of friction in the papermaking direction on the surface of the paper product by the KES method is 25 or more. The tensile strength of the paper product in the papermaking direction when dry is 1.8 N or more;
The paper product according to claim 1 or 2, wherein the tensile strength of the paper product in a dry state in a direction perpendicular to the papermaking direction is 0.6 N or more. The paper product according to claim 1 or claim 2, wherein T0 - TM is 0.100 mm or more, where T0 is a thickness at a pressure of 0.5 gf/ ^cm2 measured in a compression test according to the KES method, and TM is a thickness at a pressure of 50.0 gf/ ^cm2 measured in a compression test according to the KES method.

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