JP6004070B1 - Manufacturing method of sanitary paper and tissue paper products - Google Patents

Abstract

[Problem] To provide a sanitary paper having a good touch and excellent strength and a soft sanitary paper having a small amount of generated paper dust. A sanitary paper has a first surface and a second surface opposite to the first surface, and the HF value (hand feel value) of the first surface measured by a tissue softness analyzer. ) Is 75 or more, and the value obtained by subtracting the HF value of the second surface from the HF value of the first surface is 4 or more. [Selection] Figure 2

Description

  The present invention relates to a household sanitary paper and a tissue paper product in which a plurality of sanitary papers are stacked.

  Thin sanitary paper such as tissue paper used at home requires a certain level of tensile strength to be pulled out of a box or bag, but requires a smooth and soft texture because it touches the skin directly. Is done. On the other hand, tissue paper is also used for wiping glasses, liquid crystal screens, CD / DVD discs, etc., and requires a certain degree of flexibility and strength, but it is required that paper dust does not occur during wiping. For this reason, conventionally, the mixing ratio of the papermaking raw materials such as softwood pulp and hardwood pulp constituting the sanitary paper used and the tree species to be used is adjusted, and the softeners and paper strength enhancers added to these papermaking raw materials are used. Attempts have been made to obtain sanitary paper that is easy to touch and excellent in strength by adjusting the amount added (Patent Documents 1 to 3).

  It is also known to refer to the HF value (hand feel value) of sanitary paper as an objective index that comprehensively shows the feel of sanitary paper, the texture, smoothness, suppleness, and volume. (Patent Document 4). This HF value tends to decrease as the strength of the sanitary paper increases, and it has been assumed that if one of them is improved, the other is degraded. For this reason, it can be said that there is still room for study on techniques for simultaneously improving the HF value and strength of sanitary paper.

Japanese Patent No. 3216557 Japanese Patent No. 4762846 Japanese Patent No. 3010904 JP 2013-236903 A

  However, soft and excellent touch and strong strength are contradictory properties, and even if the techniques described in Patent Documents 1 to 3 above are used, both the high strength and good touch of sanitary paper can be satisfied. It was not enough. The amount of paper dust generated is proportional to the strength of sanitary paper, and the amount of paper dust generated increases as the strength of sanitary paper decreases. In other words, if the softness, which is in a trade-off relationship with the strength of sanitary paper, improves, the amount of paper dust generated increases.

  Therefore, an object of the present invention is to provide a sanitary paper that has a good touch and excellent strength and a sanitary paper that is soft and generates less paper dust.

  The inventor of the present invention focused on the HF value (hand feel value) of sanitary paper in the study of the means for solving the above problems. Then, while maintaining the HF value of the first surface of the sanitary paper at a certain value or more, the HF value of the second surface is deliberately lowered to greatly deviate the difference between the front and back of the HF value. As a result, a sanitary paper having a first surface that is soft to the touch and a second surface that is inferior to the touch but has a high strength, that is, a second surface that generates a small amount of paper dust. Succeeded. The inventor has conceived that the problems of the prior art can be solved based on the above knowledge, and has completed the present invention. More specifically, the present invention has the following configuration.

The first aspect of the present invention relates to sanitary paper such as tissue paper.
The sanitary paper of the present invention has a first surface and a second surface that is the surface opposite to the first surface.
The sanitary paper of the present invention has an HF value (hand feel value) of 75 or more on the first surface. The value obtained by subtracting the HF value of the second surface from the HF value of the first surface is 4 or more. That is, the HF value is higher on the first surface than on the second surface.
The above HF values are values measured with a tissue softness analyzer (manufacturer: Emtec Electronic GmbH, Japan distributor: Nippon Luft Co., Ltd.).

  As in the above configuration, the HF value of the first surface of the sanitary paper is set to 75 or more. The HF value is an index that comprehensively shows such factors as the feel of sanitary paper, texture, smoothness, suppleness, and volume. For this reason, by setting the HF value of the first surface to 75 or more, it is possible to obtain a sanitary paper excellent in touch and texture. On the other hand, on the second surface of the sanitary paper, the HF value is deliberately lowered so that the difference in HF value from the first surface is 4 or more. Thus, by increasing the difference in the HF value between the first surface and the second surface, the sanitary paper has a first surface that is unexpectedly good in touch and a second surface that generates less paper dust. As a whole, sanitary paper with high tensile strength could be obtained. Therefore, make tissue paper products with two or more sanitary papers, and make the first paper side of this sanitary paper the outer surface that touches the user's skin directly, making the tissue paper products with good touch and excellent strength. Can do. Further, by making the second surface of the sanitary paper the outside, it is possible to obtain a tissue paper product that is soft and generates a small amount of paper dust.

  In the sanitary paper of the present invention, the value obtained by subtracting the HF value of the second surface from the HF value of the first surface is preferably 7 or more.

  As described above, the difference in the HF value between the first side and the second side is further increased to 7 or more, so that sanitary paper that is easy to touch and has excellent strength and soft sanitary paper that generates less paper dust. The effect of the present invention obtained can be further improved.

  In the sanitary paper of the present invention, the first papermaking raw material constituting the first surface preferably contains 90 to 100% by mass of hardwood pulp relative to the total mass of pulp contained in the first papermaking raw material. Moreover, it is preferable that the 2nd papermaking raw material which comprises a 2nd surface contains 20-100 mass% of softwood pulp with respect to the total mass of the pulp contained in this 2nd papermaking raw material.

  As in the above configuration, the sanitary paper is composed of two layers of papermaking raw materials, the first surface being a hardwood pulp main surface and the second surface being a softwood pulp main surface. Hardwood pulp is thin and supple and has good flexibility and touch, but has a short fiber length and insufficient tensile strength. On the other hand, softwood pulp is rigid and has high tensile strength, but it has the characteristics of poor flexibility and touch. Therefore, in order to compensate for the mutual disadvantages of softwood pulp and hardwood pulp, taking into account these characteristics, a papermaking raw material mainly containing coniferous pulp and a papermaking raw material mainly containing hardwood pulp are used to form two layers. It is preferable to combine them.

  The second aspect of the present invention is a tissue paper product in which two or more sanitary sheets according to the first aspect described above are stacked. The tissue paper product according to the second aspect may be superposed so that the first surface (surface with high HF value) of the sanitary paper is the outer surface, or the second surface (HF value) of the sanitary paper. May be superposed such that the lower surface is the outer surface.

  As described above, for example, two-ply and three-ply sanitary papers are known which are formed by stacking a plurality of sanitary papers. As described above, the first surface of the sanitary paper has an HF value of 75 or more and has an excellent feel and texture. Therefore, the first surface can be used as an outer surface that directly touches the user's skin. A feeling can be provided. In addition, as described above, the second surface of the sanitary paper has a low HF value, but has high strength and generates a very small amount of paper dust. By making this second surface the outer surface, precision instruments such as CDs and DVD disks can be used. When used for wiping off the paper, there is no loss of paper dust and there is no hindrance to data reading.

  A third aspect of the present invention is a tissue paper product in which two or more sanitary sheets according to the first aspect described above are stacked, and is a tissue paper product containing a moisturizing liquid on at least one of its outer surfaces. By containing the moisturizing liquid, a moist feel can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, the sanitary paper which is easy to touch and excellent in intensity | strength, and the sanitary paper which is soft and has little generation amount of paper dust can be provided.

FIG. 1 is a schematic diagram showing an example of a forming unit that can perform two-layer papermaking of papermaking raw materials. FIG. 2 is a distribution diagram in which the ordinate represents the HF value of the first surface and the abscissa represents the difference between the first and second surfaces of the HF value. FIG. 3 is a distribution diagram in which the vertical axis represents the sensory evaluation score and the horizontal axis represents the measurement result of the dry tensile strength. FIG. 4 is a distribution diagram in which the vertical axis represents the HF value of the first surface, and the horizontal axis represents the difference value between the first surface and the second surface of the HF value. FIG. 5 is a distribution diagram in which the vertical axis represents the amount of paper dust generated and the horizontal axis represents the measurement result of the paper bending stiffness (KES-B).

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. This invention is not limited to the form demonstrated below, The thing suitably changed in the range obvious to those skilled in the art from the following forms is also included.
In the present specification, “A to B” means “A to B”.

The present invention relates to a household sanitary paper used as tissue paper or toilet paper. In particular, the sanitary paper of the present invention is preferably a thin paper having a basis weight in the range of 10 to 25 g / m ² . In addition, the sanitary paper of the present invention can be a two-ply product or a three-ply product by superimposing two or three or more sheets.

  The sanitary paper of the present invention can be manufactured using a general paper machine. A typical paper machine has a wire part, a press part, a dryer part, a calendar part, and a reel part.

  The wire part is a process in which the injected papermaking raw material (pulp) is dehydrated to form a sheet. In the wire part, the papermaking raw material whose components are prepared in advance is supplied to the forming unit in a state of containing a large amount of moisture, thereby forming a two-layered paper layer that becomes a prototype of sanitary paper. A large amount of moisture contained in the papermaking raw material is dehydrated here, and the texture of the wet paper is prepared. The specific configuration of the forming unit will be described later in detail.

  The press part is a process in which pressure is applied to the papermaking material that has been made into a sheet to further dehydrate it. In the press part, pressure is applied to the two-layer wet paper formed in the wire part and the water contained in the wet paper is squeezed out. Here, the surface of the wet paper is smoothed, and at the same time, the density of the pulp component constituting the main part of the wet paper is increased to form a strong wet paper.

  The dryer part is a process in which a sheet of papermaking raw material is introduced into the dryer and completely dried by applying heat. In the dry part, excess water is forcibly evaporated by heating the wet paper that has passed through the press part with a Yankee dryer. As a result, paper obtained by drying the wet paper is obtained. The paper wound around the mirror roll of the Yankee dryer and dried is peeled off from the surface of the mirror roll while being creped by a creping doctor, and is transported to a subsequent calendar part.

  The calendar part is a process in which the surface of the sheet after drying is stretched while being pressed to smooth the surface of the sheet. In other words, in the calendar part, the paper in a nearly completed state is introduced between a pair of calendar rolls, thereby smoothing the surface of the paper and increasing its density.

  The reel part is a step of winding a long paper obtained through each step to form a roll body in which the paper is wound in multiple layers. At the reel part, the finished paper, that is, the base paper of sanitary paper that becomes a piece of tissue paper, is wound up in a roll. After that, two sanitary paper rolls obtained through the above-mentioned process are prepared, and they are stacked and cut in a separate process, so that two sets of tissue paper products (2-ply) Can be obtained. Also, by preparing three rolls of sanitary paper base paper, it is possible to obtain a set of three (three ply) tissue paper products.

  Next, the forming unit installed in the wire part will be described in detail with reference to FIG. As shown in FIG. 1, the forming unit 11 includes a forming roll 18, endless inner wires 12 and outer wires 13, and a plurality of guide rolls 21. A driving force applied to a driving roll (not shown) is transmitted to the forming roll 18 and the guide roll 21. Then, when the forming roll 18 and the guide roll 21 rotate synchronously, the inner wire 12 and the outer wire 13 wound so as to be in contact with a part of the peripheral surface of the forming roll 18 travel at the same speed. As a result, an initial forming region Z is formed in a region between the inner wire 12 and the outer wire 13 wound around the peripheral surface of the forming roll 18. The initial forming area Z is a curved area for paper making and initial dehydration of the paper layer C, and is formed between the inner wire 12 and the outer wire 13.

  As shown in FIG. 1, the forming unit 11 further includes a head box 19. The head box 19 is an apparatus for simultaneously supplying two types of papermaking materials toward the curved initial forming region Z. Inside the head box 19, two raw material chambers 23 a and 23 b for introducing two types of papermaking raw materials to the discharge port are provided with a partition wall 24 therebetween. A first papermaking raw material prepared by a preparation facility (not shown) is supplied to the first raw material chamber 23a. Similarly, a second papermaking raw material adjusted by a preparation facility (not shown) is supplied to the second raw material chamber 23b. The first papermaking raw material in the first raw material chamber 23a and the second papermaking raw material in the second raw material chamber 23b are separated by the partition wall 24 and guided to the discharge port without being mixed with each other. . As described above, when two types of papermaking raw materials are simultaneously ejected from the head box 19, the first paper layer A mainly composed of the first papermaking raw material is formed on the outer wire 13 side, and the first paper layer A is formed on the inner wire 12 side. A second paper layer B mainly composed of the second papermaking raw material is formed. Then, the paper layer A and the paper layer B are integrated to form a paper layer (wet paper) in a two-layered state. Thereafter, the paper layer is conveyed from the initial forming area Z toward the subsequent press part via the inner wire 12.

  By using the head box 19 having the above-described configuration, a sanitary paper composed of the first paper layer A mainly composed of the first papermaking raw material and the second paper layer B mainly composed of the second papermaking raw material is manufactured. be able to. Then, by adjusting the first papermaking raw material and the second papermaking raw material to different components, the first paper layer A (front surface: first surface) and the second paper layer B (back surface: second surface) of the sanitary paper. The surface property values and other properties can be varied. For example, in the first papermaking raw material and the second papermaking raw material, various blending ratios of softwood pulp and hardwood pulp, addition amount of a softening agent and a paper strength enhancer, and whether or not the pulp fiber is beaten. Ingredients and conditions can be varied. As a result, the physical property values of the front and back surfaces of the sanitary paper can be freely adjusted to some extent independently. Moreover, as a physical property value of the sanitary paper here, tensile strength, HF value (hand feel value), and the like can be given as representative examples.

  For example, when it comes to sanitary papermaking raw materials, softwood pulp is rigid and has high tensile strength, but it has the characteristics of poor flexibility and touch. In contrast, hardwood pulp is thin, pliable and has good flexibility and touch, but has a short fiber length and low tensile strength. For this reason, in order to increase the strength of sanitary paper, the blending ratio of softwood pulp may be increased. On the other hand, in order to improve the feel of sanitary paper, the blending ratio of hardwood pulp may be increased.

  As for chemicals added to papermaking raw materials, adding a paper strength enhancer such as a dry paper strength agent or a wet paper strength agent to papermaking materials has the effect of increasing the strength of sanitary paper. And the property that the smoothness decreases. In contrast, the addition of a softening agent to the papermaking raw material has the effect of improving the flexibility and feel of the sanitary paper, but has the property of reducing the strength of the sanitary paper. For this reason, a paper strength enhancer may be added to increase the strength of the sanitary paper, and a softener may be added to improve the touch of the sanitary paper.

  In addition, beaten pulp fibers used as raw materials for papermaking (softwood pulp, hardwood pulp, etc.) can strengthen the bond between fibers and increase the tensile strength, but on the other hand, they become stiff so that the sanitary paper has flexibility and touch. Will be reduced. For this reason, when emphasizing the touch of sanitary paper, unbeaten pulp fibers may be used as the papermaking raw material.

  As described above, the ingredients of the papermaking material affect the physical properties such as the strength and touch of the sanitary paper. Factors affecting the physical properties of sanitary paper include the ratio of pulp fiber, the presence or absence of chemicals, the presence or absence of beating, and the presence or absence of beating work. The value changes. Furthermore, as described above, when sanitary paper is in a two-layered state and the first papermaking material constituting the front surface and the second papermaking material constituting the back surface are independently adjusted, The raw material preparation conditions are further complicated.

Accordingly, the inventors of the present invention have repeatedly studied focusing on the HF value indicating the physical property value of sanitary paper. As a result, sanitary paper with two-layer stitching satisfies the following conditions [a] and [b]. As a result, it was found that the strength can be maintained high and the touch can be improved.
[A] The HF value of the first surface is 75.0 or more.
[B] The value obtained by subtracting the HF value of the second surface from the HF value of the first surface is 4.0 or more. In particular, the value obtained by subtracting the HF value of the second surface from the HF value of the first surface is preferably 7.0 or more.

[Measurement condition of HF value]
Here, in the present specification, “HF value” means a value measured according to the following measurement conditions.
・ Measuring machine: tissue softness analyzer ・ Manufacturer: Emtec Electronic GmbH (Germany)
・ Japan agency: Nippon Luft Co., Ltd. ・ Standard sample shape: Sample cut into a circle with a diameter of about 112.8 mm ・ Measurement environment: Environment conforming to ISO 187 (23 ° C. ± 1 ° C., humidity 50% (± 2%))
・ Measurement conditions: 1 point calibration with standard sample (emtec ref.2X (nn.n)) according to the attached instruction, and the algorithm is set to facial II. The calculation software used was emtec measurement system ver.2.98.
For the sample installed on the sample stage, the vibration frequency when the rotor with blade is pushed from above with an indentation pressure of 100 mN and rotated at a rotation speed of 2.0 (/ sec), and the sample installed on the sample stage The HF value (hand feel value) can be obtained from the amount of deformation in the vertical direction when the bladed rotor is pushed from above with a pushing pressure of 100 mN and 600 mN without rotating the bladed rotor. The measurement is performed 8 times for each of the front and back surfaces of each sample, and the average value of 8 acquired HF values is excluded from the average value exceeding ± 2 x [standard deviation of the average value] , and then averaged again. To obtain the HF values of the front and back surfaces of each sample.

  As described above, by setting the HF value of the first surface of the sanitary paper to 75 or more, the touch and texture of the sanitary paper can be improved. In particular, the HF value of the first surface is preferably 77 or more. The upper limit of the HF value of the first surface is not particularly limited, but is preferably 85 or 80, for example. If the HF value is less than 75, it is impossible to give the user a feeling that the touch and texture are good. When the HF value exceeds 85, there is a concern that the surface strength of the sanitary paper is significantly reduced and paper dust is likely to be generated. For this reason, the HF value of the first surface is preferably in the range of 75 to 85.

  On the other hand, on the second surface of the sanitary paper, the HF value is deliberately lowered so that the difference in HF value from the first surface is 4.0 or more, preferably 7.0 or more. In this way, by increasing the difference in the HF value between the first and second surfaces, the overall tensile strength of the sanitary paper can be unexpectedly increased while maintaining the goodness of the first surface. It was. Therefore, by using the first surface as the outer surface of the sanitary paper, it can be used as a sanitary paper having a good touch and excellent strength. On the other hand, the second surface has a lower HF value than the first surface, but has a high strength, and therefore generates less paper dust. Therefore, by using the second surface as the outer surface of the sanitary paper, the sanitary paper can be used as a sanitary paper with less generation of paper dust without reducing the softness of the entire sanitary paper.

  The upper limit value of the difference between the HF values of the first and second surfaces of the sanitary paper (the HF value of the first surface−the HF value of the second surface) is not particularly limited. For example, 20, 15, or 10 It is preferable that If the difference between the HF values of the first and second surfaces exceeds 20 or 15, the physical property values of the first and second surfaces of the sanitary paper will be too different from each other. The bonding force of the papermaking raw material on the surface is weakened, and paper dust may be easily generated from either the first surface or the second surface. The difference in HF value between the first surface and the second surface is preferably in the range of 4-20 or 7-15.

  Further, the HF value of the second surface of the sanitary paper may be a value that is 4.0 or more or 7.0 or more different from the HF value of the first surface, but is preferably 55 to 75, for example. If the HF value of the second surface is less than 55, the difference from the HF value of the first surface exceeds 20, so that the physical property values of the first and second surfaces of the sanitary paper are different as described above. Too much. On the other hand, if the HF value of the second surface exceeds 75, the HF values of the first surface and the second surface both become too high, making it difficult to maintain the strength of the sanitary paper as a whole. Therefore, the HF value of the second surface of the sanitary paper is preferably in the range of 55 to 75.

  As described above, if it satisfies the minimum condition [a] of the HF value of the first surface and the condition [b] of the difference between the HF values of the first surface and the second surface, the touch is good and the strength is excellent. Sanitary paper and soft sanitary paper that generates less paper dust can be obtained. In order to obtain such sanitary paper, a known production method and papermaking raw material preparation conditions may be adopted as appropriate to satisfy the above conditions [a] and [b]. That is, there are no particular limitations on the method for producing sanitary paper, the components of the papermaking raw material, or the amount of chemicals added.

  Examples of cellulose fiber raw materials for forming sanitary paper include chemical pulps such as kraft pulp (KP), sulfite pulp (SP) and soda pulp (AP), semi-chemical pulp (SCP), and chemiground wood pulp (CGP). Such as semi-chemical pulp such as wood pulp (GP), thermomechanical pulp (TMP, BCTMP), etc., or non-wood pulp made from straw, cocoon, hemp, kenaf, etc., cotton linter, cotton lint, etc. Examples include cotton-based pulp and deinked pulp made from waste paper. These may be used alone or in combination of two or more.

  For example, in the sanitary paper of the present invention, it is preferable that the first papermaking raw material constituting the first surface is mainly hardwood pulp. For example, the first papermaking material constituting the first surface preferably contains 90 to 100% by mass of hardwood pulp with respect to the total mass of pulp contained in the first papermaking material. On the other hand, it is preferable that the 2nd papermaking raw material which comprises a 2nd surface is 10-100 mass% of coniferous pulp with respect to the total mass of the pulp contained in this 2nd papermaking raw material, Especially 20- It is preferable to contain 100% by weight, 20 to 80% by weight, or 20 to 70% by weight.

  Further, for example, a dry paper strength agent, a wet strength strength agent, a softening agent, and the like can be added to the papermaking raw material of sanitary paper. A dry paper strength agent is a chemical for increasing the strength of paper in a dry state. As the dry paper strength agent, known ones such as cationized starch, polyacrylamide (PAM), and carboxymethyl cellulose (CMC) can be used alone or in admixture of two or more. The wet paper strength enhancer is a drug for suppressing a decrease in paper strength when the paper gets wet. As the wet paper strength enhancer, for example, known materials such as polyamide / epichlorohydrin resin, urea resin, melamine resin, and thermal crosslinkability imparting polyacrylamide (PAM) can be used alone or in combination of two or more. . A softener is a drug for improving the softness of paper. As the softening agent, for example, an anionic surfactant, a nonionic surfactant, a cationic surfactant, and a zwitterionic surfactant may be used alone or in combination of two or more. Can do.

  For example, in the sanitary paper of the present invention, it is preferable to add a softening agent only to the first papermaking raw material mainly composed of hardwood pulp constituting the first surface. The softening agent may be added at 0.01 to 0.50 mass% with respect to the total mass of the pulp contained in the first papermaking raw material. In particular, the addition amount of the softening agent is preferably 0.015 to 0.10% by mass. On the other hand, it is preferable not to add a softener to the second papermaking raw material mainly composed of softwood pulp constituting the second surface. However, there is no problem even if a softening agent of 1/10 or less of the first papermaking raw material is added to the second papermaking raw material.

  Further, in the sanitary paper of the present invention, a paper strength enhancer such as a wet paper strength agent or a dry paper strength agent may be added to the papermaking raw material on both the first side and the second side. For example, the paper strength enhancer may be added at 0.01 to 0.15 mass% or 0.05 to 0.10 mass% with respect to the total mass of pulp contained in the papermaking raw material.

  Further, a moisturizing tissue can be obtained by using the sanitary paper of the present invention as a base paper and applying or impregnating a moisturizing component such as polyhydric alcohol. Examples of moisturizing ingredients include, but are not limited to, polyhydric alcohols such as glycerin, diglycerin, polyglycerin, polyethylene glycol, propylene glycol, fructose, glucose, oligosaccharide, trehalose, lactic acid, sodium lactate, and the like. It is not a thing.

  Further, for example, the surface of the sanitary paper is preferably a surface (yankee surface) in contact with the mirror surface roll of the Yankee dryer in the above-described dryer part for drying the wet paper. On the other hand, the back surface of the sanitary paper is a surface that is not in contact with the mirror roll of the Yankee dryer (non-yankee surface). The HF value of the Yankee surface is improved. On the other hand, the non-Yankee surface has a lower HF value than the Yankee surface. For this reason, by setting the first surface of the sanitary paper as the Yankee surface, it is possible to increase the HF value of the first surface and widen the difference between the HF values of the first surface and the second surface.

  As described above, in the present invention, the sanitary paper is manufactured in order to satisfy the minimum condition [a] of the HF value of the first surface and the condition [b] of the difference between the HF values of the first surface and the second surface. In addition, it is possible to appropriately devise the components of the papermaking raw material or the amount of the chemical added. Regardless of the manufacturing method of these sanitary papers and the papermaking raw material preparation conditions, if sanitary papers satisfy the above conditions [a] and [b], sanitary papers that do not satisfy either or both of these conditions In comparison, sanitary paper having a good touch and excellent strength and a sanitary paper that is soft and generates less paper dust can be obtained. Examples for confirming the effects of the present invention will be described below.

  Tables 1 and 2 show a list of various measurement results relating to examples and comparative examples of the present invention. Table 1 shows general-purpose tissue paper products, and Table 2 shows tissue paper products for wiping precision instruments such as CDs and DVD disks. 2 and 4 are distribution diagrams in which the vertical axis represents the HF value of the first surface and the horizontal axis represents the difference value between the first surface and the second surface of the HF value. 2 is a data distribution chart shown in Table 1, and FIG. 4 is a data distribution chart shown in Table 2. FIG. 3 is a distribution diagram regarding the data in Table 1, with the vertical axis representing the sensory evaluation score and the horizontal axis representing the measurement result of the dry tensile strength. FIG. 5 is a distribution diagram regarding the data in Table 2, in which the vertical axis represents the amount of paper dust generated and the horizontal axis represents the measurement result of the paper bending stiffness (KES-B).

  In this example and comparative example, a two-ply tissue paper product was targeted. Two-ply tissue paper products were peeled off one by one to make individual sanitary paper. The sanitary paper has a surface corresponding to the outer surface of the tissue paper product as the front surface and a surface corresponding to the inner surface of the tissue paper product as the back surface. In the general tissue paper products shown in Table 1, the first surface of the sanitary paper was the front surface, and the second surface of the sanitary paper was the back surface. On the other hand, in the tissue paper products for wiping such as precision instruments shown in Table 2, the first surface of the sanitary paper is the back surface and the second surface of the sanitary paper is the front surface. The “front side” means the surface of the sanitary paper that is supposed to directly touch the object to be wiped (user's skin, precision equipment, etc.), and the “back side” is opposite to this surface. Means the side face. In other words, a two-ply tissue paper product is a stack of sanitary paper with the backs facing each other.

In Example 1 of the present invention, 40% of hardwood kraft pulp (hereinafter referred to as “LBKP”) is blended in the first papermaking material constituting the first side of the entire pulp slurry (100%), and the second side is constituted. The second papermaking material to be blended was 50% softwood kraft pulp (hereinafter "NBKP") and 10% LBKP. That is, the weight ratio of the first papermaking raw material to the second papermaking raw material was about 4: 6. The first papermaking material was LBKP 100%, and the second papermaking material was LBKP 17% and NBKP 83%. Also, in the pulp slurry, a wet paper strength agent is added to each of the first papermaking raw material (first side) and the second papermaking raw material (second side) by 0.09% by weight (vs. pulp weight). , 0.02 wt% (vs. pulp weight) was added to the first papermaking raw material (first side) only. The additive chemical used was a wet paper strength agent made by Arakawa Chemical Industries, Ltd. and a softener made by Seiko PMC Co., Ltd. The pulp slurry thus prepared was made using a two-layer crescent former to obtain a sanitary paper having a basis weight of 11.2 g / m ² . The first side of the sanitary paper was the Yankee side (the side in contact with the mirror roll of the Yankee dryer), and the second side was the non-Yankee side (the side not in contact with the mirror roll of the Yankee dryer). A general-purpose tissue paper product was obtained by superimposing the obtained two sanitary paper sheets so that the first surface was the outer surface.

In Example 2 of the present invention, 50% of LBKP was blended in the first papermaking material constituting the first side of the whole pulp slurry (100%), and NBKP in the second papermaking raw material constituting the second surface. 10% and LBKP 40%. That is, the weight ratio of the first papermaking raw material to the second papermaking raw material was about 5: 5. The first papermaking material was LBKP 100%, and the second papermaking material was LBKP 80% and NBKP 20%. Also, in the pulp slurry, a wet paper strength agent is added to each of the first papermaking raw material (first side) and the second papermaking raw material (second side) by 0.09% by weight (vs. pulp weight). , 0.11 wt% (vs. pulp weight) was added only to the first papermaking raw material (first side). The same wet paper strength agent and softening agent as in Example 1 were used. The pulp slurry thus prepared was made using a two-layer crescent former to obtain a sanitary paper having a basis weight of 13.9 g / m ² . In addition, the sanitary paper had a first side as a Yankee side and a second side as a non-Yankee side. A general-purpose tissue paper product was obtained by superimposing the obtained two sanitary paper sheets so that the first surface was the outer surface.

In Example 3 of the present invention, two sheets of sanitary paper obtained in Example 2 were superposed so that the first side would be the outer surface, and then a moisturizing agent was applied to obtain a general-purpose moisturizing tissue paper product. It was. A moisturizer manufactured by Miyoshi Oil & Fat Co., Ltd. was used as the moisturizer. The moisturizing agent was applied to the tissue paper so as to contain 9.4% by weight with respect to 100 parts by weight of the tissue paper. In other words, the humectant was 2.6 g / ^{m 2} coating against tissue paper 27.8 g / ^{m 2} of 2-ply.

  In Example 4 of the present invention, two sanitary papers obtained in Example 1 were overlapped so that the second surface became the outer surface, thereby obtaining a tissue paper product for wiping precision equipment.

  In Example 5 of the present invention, two sanitary paper sheets obtained in Example 2 were overlapped so that the second surface was the outer surface, thereby obtaining a tissue paper product for wiping precision equipment.

In Example 6 of the present invention, the second surface obtained in Example 2 was overlapped so as to be the outer surface, and then a moisturizing agent was applied to obtain a moisturizing tissue paper product for wiping precision equipment. A moisturizer manufactured by Miyoshi Oil & Fat Co., Ltd. was used as the moisturizer. The moisturizing agent was applied to the tissue paper so as to contain 9.4% by weight with respect to 100 parts by weight of the tissue paper. In other words, the humectant was 2.6 g / ^{m 2} coating against tissue paper 27.8 g / ^{m 2} of 2-ply.

In Comparative Example 1, 80% LBKP and 20% NBKP were blended in the whole pulp slurry (100%). To the pulp slurry, 0.08% by weight of wet paper strength agent (vs. pulp) and 0.25% by weight of softener (vs. pulp) were added. The same wet paper strength agent and softening agent as in Example 1 were used. The pulp slurry prepared in this way was made using a long paper machine to obtain sanitary paper having a basis weight of 13.9 g / m ² . In addition, the sanitary paper had a first side as a Yankee side and a second side as a non-Yankee side. A general-purpose tissue paper product was obtained by superimposing the obtained two sanitary paper sheets so that the first surface was the outer surface.

In Comparative Example 2, 50% LBKP and 50% NBKP were blended out of the whole pulp slurry (100%). To the pulp slurry, a wet paper strength agent was added in an amount of 0.08% by weight (vs. pulp), and a softening agent was added in an amount of 0.10% by weight (vs. pulp). The same wet paper strength agent and softening agent as in Example 1 were used. The pulp slurry thus prepared was made using a long paper machine to obtain sanitary paper having a basis weight of 12.0 / m ² . In addition, the sanitary paper had a first side as a Yankee side and a second side as a non-Yankee side. A general-purpose tissue paper product was obtained by superimposing the obtained two sanitary paper sheets so that the first surface was the outer surface.

  Comparative Example 3 and Comparative Example 4 are commercially available products made by other companies. As comparative example 3 and comparative example 4, what purchased the commercial item was used.

  In Comparative Example 5, a tissue paper product for wiping precision instruments was obtained by superimposing the two sanitary papers obtained in Comparative Example 1 so that the second surface was the outer surface.

  In Comparative Example 6, a tissue paper product for wiping precision instruments was obtained by superimposing the two sanitary papers obtained in Comparative Example 2 so that the second surface was the outer surface.

  Comparative Example 7 and Comparative Example 8 are commercially available products made by other companies. As Comparative Example 7 and Comparative Example 8, commercially available products were used.

  For each of Examples 1 to 6 and Comparative Examples 1 to 8, the HF value, basis weight, thickness, and dry tensile strength of a two-ply tissue paper product were measured. Moreover, about each of above-mentioned Examples 1-3 and Comparative Examples 1-4, the HF value of the tissue paper product of 2 plies was measured, and sensory evaluation of the touch was performed. Further, for each of Examples 4 to 6 and Comparative Examples 5 to 8 described above, the amount of paper dust generated and bending stiffness (KES-B value) of a two-ply tissue paper product were measured.

  A tissue softness analyzer (Emtec Electronic GmbH) was used to measure the HF value of sanitary paper. The measurement environment and measurement conditions are as described in [Measurement conditions for HF value].

  The measured value of the basis weight indicates the measured value of one ply (that is, individual sanitary paper) constituting the tissue paper product. The basis weight was measured in accordance with JIS P8124.

  The thickness measurement value indicates the measurement value of one ply (that is, individual sanitary paper) constituting the tissue paper product. The thickness was read when the probe was lowered at a speed of 1 mm or less per second using a thickness meter (manufactured by Highbridge Seisakusho) in an environment conforming to ISO187. In addition, the measurement measured eight samples one by one, and averaged the acquired eight thicknesses.

  The HF value of tissue paper products is the value measured with 2 plies. The HF value of the tissue paper product is the same as the measurement condition of the HF value of the sanitary paper described above.

  Sensory evaluation of tissue paper products was carried out with 2 plies. The sensory evaluation was divided into five grades (5: good 4: slightly good 3: normal 2: slightly bad 1: bad), and the average of 20 testers for each gender (total of 40) The value was determined. The result of sensory evaluation shown in Table 1 is a value obtained by rounding down the second average of the obtained average value. As a result of sensory evaluation, an average score of 3.5 or less was considered inappropriate.

  The tissue paper product was dried with a two-ply tensile strength. The dry tensile strength was measured according to JIS P8113. When the geometric average of the dry tensile strength in the machine direction and the transverse direction is less than 1.5 [N / 25 mm], troubles such as paper breakage occur during paper making. For this reason, as the measurement result of the dry tensile strength, those having a geometric average of 1.5 [N / 25 mm] or less were considered inappropriate.

  Measurement of the amount of paper dust of tissue paper products was carried out with 2 plies. The amount of paper dust is extracted from the tissue paper box at intervals of 0.5 seconds according to the metronome, and the paper dust scattered at that time, the paper dust accumulated in the box, and the paper dust adhering to the film window are removed. Collected and weighed. The same test was performed 5 times, and the average value was defined as the amount of paper dust of each sample. If the amount of paper dust exceeds 5 mg, paper dust may adhere when wiping CDs and DVD discs, etc., which may interfere with data reading. did.

The tissue paper product was subjected to a bending stiffness (KES-B value) of 2 plies. The KES-B value is based on KES (Kawabata Evaluation System), which is well-known as an objective evaluation method for the texture of fabric for clothes, and is used as an index of flexibility. When the geometric average of the KES-B values in the vertical direction and the horizontal direction exceeds 0.015 [g · cm ² / cm], the flexibility becomes poor. The details of the measurement contents related to the KES-B value are known in the manual of the testing machine manufactured by Kato Tech Co., Ltd., but are also known in Japanese Patent Application Laid-Open No. 2004-60114.

First, a general-purpose tissue paper product in which two first sheets of sanitary paper (surface having a high HF value) are overlapped is considered. Regarding the test results of general-purpose tissue paper products,
It is shown in Table 1, FIG. 2, and FIG.

  As shown in Table 1 above, Comparative Example 1 had a HF value of 75 or more on the first surface (front surface), but the front-back difference of the HF value was less than 4. As a result, in Comparative Example 1, the geometric average of the dry tensile strength was less than 1.5 [N / 25 mm]. Therefore, in Comparative Example 1, it is difficult to make paper, and there is a high possibility of breakage when taking out from the box.

  In Comparative Example 2, the HF value was less than 75 on both the first surface (front surface) and the second surface (back surface), and the front-back difference in HF value was also less than 4. As a result, Comparative Example 2 had a sensory evaluation score of 3.1 and was not excellent in touch.

  In Comparative Example 3, the HF value of the first surface (front surface) was less than 75, although the difference in front and back of the HF value was 4 or more. As a result, in Comparative Example 3, the sensory evaluation score was 3.4, and it was not recognized that the touch was good.

  In Comparative Example 4, the HF value was less than 75 on both the first surface (front surface) and the second surface (back surface), and the front-back difference in HF value was also less than 4. As a result, Comparative Example 4 had a sensory evaluation score of 2.9 and was not excellent in touch.

  Compared with the comparative examples 1 to 4, in Example 1 of the present invention, the HF value of the first surface (front surface) was 77.6, and at the same time, the front-back difference of the HF value was 13.6. As a result, in Example 1, the sensory evaluation score was 4.0, which was recognized as having excellent touch. In Example 1, the geometric average of the dry and tensile strengths in the machine direction and the transverse direction was 2.67 [N / 25 mm], and it had sufficient strength to withstand papermaking.

  In Example 2 of the present invention, the HF value of the first surface (surface) was 77.7, and at the same time, the difference between the front and back of the HF value was 7.6. As a result, in Example 2, the sensory evaluation score was 4.7, which was recognized as having an excellent touch. Further, in Example 2, the geometric average of the dry tensile strength in the machine direction and the transverse direction was 1.87 [N / 25 mm], and it had sufficient strength to withstand papermaking.

  In Example 3 of the present invention, the HF value of the first surface (surface) was 77.7, and at the same time, the difference between the front and back of the HF value was 7.6. Furthermore, Example 3 contains a humectant. As a result, Example 3 had a sensory evaluation score of 4.9, the highest score, and was recognized as having the best touch. Further, in Example 3, the geometric average of the dry tensile strength in the machine direction and the transverse direction was 1.72 [N / 25 mm], and it had sufficient strength to withstand papermaking.

  As described above, sanitary paper has an HF value of 75.0 or more on the front surface, and a value obtained by subtracting the HF value on the back surface from the HF value on the front surface is 4.0 or more. It was confirmed that it would have

  Subsequently, a tissue paper product for wiping precision equipment in which two sheets of sanitary paper (surface having a low HF value) are overlapped as an outer surface will be examined. Table 2, Fig. 4, and Fig. 5 show the test results of tissue paper products for wiping precision instruments.

  As shown in Table 2 above, in Comparative Example 5, although the HF value on the first surface (back surface) was 75 or more, the front-back difference in HF value was less than 4. As a result, in Comparative Example 5, the amount of paper dust generated was 6.7 [mg / box], and the amount of paper dust generated was large. Therefore, Comparative Example 5 is not suitable as a tissue paper product for wiping precision equipment.

In Comparative Example 6, the HF value was less than 75 on both the first surface (back surface) and the second surface (front surface), and the front-back difference in HF value was also less than 4. As a result, Comparative Example 6 had a flexural rigidity of 0.0154 [g · cm ² / cm], which exceeded the reference value of 0.015 [g · cm ² / cm]. For this reason, Comparative Example 6 lacks flexibility and is not suitable for wiping precision equipment.

  In Comparative Example 7, the HF value of the first surface (back surface) was less than 75, although the difference in front and back of the HF value was 4 or more. As a result, in Comparative Example 7, the amount of paper dust generated was 5.3 [mg / box], and the amount of paper dust generated was large. For this reason, Comparative Example 7 is not suitable as a tissue paper product for wiping precision equipment.

In Comparative Example 8, the HF value was less than 75 on both the first surface (back surface) and the second surface (front surface), and the difference between the front and back of the HF value was less than 4. As a result, the comparative example 8 had a flexural rigidity of 0.0174 [g · cm ² / cm], which exceeded the reference value of 0.015 [g · cm ² / cm]. For this reason, Comparative Example 8 lacks flexibility and is not suitable for wiping precision equipment.

Compared with the comparative examples 5 to 8, in Example 4 of the present invention, the HF value of the first surface (back surface) was 77.6, and at the same time, the difference between the front and back of the HF value was 13.6. As a result, in Example 4, the amount of paper dust generated was very small as 0.7 [mg / box], the bending rigidity was 0.0115 [g · cm ² / cm], and excellent flexibility was obtained. It was.

In Example 5 of the present invention, the HF value of the first surface (back surface) was 77.7, and at the same time the difference between the front and back of the HF value was 7.6. As a result, in Example 5, the amount of paper dust generated was as small as 3.2 [mg / box], and the bending rigidity was 0.0094 [g · cm ² / cm], which had excellent flexibility. .

In Example 6 of the present invention, the HF value of the first surface (back surface) was 77.7, and the difference between the front and back of the HF value was 7.6. Furthermore, Example 6 contains a humectant. As a result, in Example 6, the amount of paper dust generated was as small as 2.7 [mg / box], the bending rigidity was 0.0064 [g · cm ² / cm], and extremely excellent flexibility. It was.

  As described above, sanitary paper is softened by setting the front surface HF value to 75.0 or higher and subtracting the back surface HF value from the front surface HF value to 4.0 or higher. It has been confirmed that the amount of generated is reduced. Therefore, it was confirmed that Examples 4 to 6 have practical performance as tissue paper products for wiping precision instruments.

  As mentioned above, in this specification, in order to express the content of the present invention, the embodiment and the example of the present invention were described. However, the present invention is not limited to the above-described embodiments and examples, but includes modifications and improvements obvious to those skilled in the art based on the matters described in this specification.

  The present invention can be suitably used in the manufacturing industry of household sanitary paper and tissue paper products.

DESCRIPTION OF SYMBOLS 11 ... Forming unit 12 ... Inner wire 13 ... Outer wire 18 ... Forming roll 19 ... Head box 21 ... Guide roll 23a ... First raw material chamber 23b ... Second raw material chamber 24 ... Partition wall A ... First paper layer B ... second paper layer C ... paper layer Z ... initial forming area

Claims (5)

After separately adjusting the first papermaking raw material constituting the first surface and the second papermaking raw material constituting the second surface opposite to the first surface, the first papermaking raw material and A method of producing sanitary paper having the first side and the second side by combining the second papermaking raw material into two layers,
The first papermaking raw material contains 90 to 100% by mass of hardwood pulp with respect to the total mass of pulp contained in the first papermaking raw material,
The second papermaking raw material contains 20 to 100% by mass of softwood pulp with respect to the total mass of pulp contained in the second papermaking raw material.
A step of adding a softener only to the first papermaking raw material among the first papermaking raw material and the second papermaking raw material,
The HF value (hand feel value) of the first surface measured with a tissue softness analyzer is 75 or more, the HF value of the second surface measured with a tissue softness analyzer is 70.1 or less, and A method for producing sanitary paper, wherein a sanitary paper having a value obtained by subtracting the HF value of the second surface from the HF value of the first surface is 4 or more. The sanitary paper manufacturing method according to claim 1, wherein a value obtained by subtracting the HF value of the second surface from the HF value of the first surface is 7 or more. A method for manufacturing a tissue paper product in which two or more sanitary sheets obtained by the manufacturing method according to claim 1 or 2 are stacked,
A method for manufacturing a tissue paper product, comprising a step of superposing the sanitary paper such that the first surface is an outer surface. A method for manufacturing a tissue paper product in which two or more sanitary sheets obtained by the manufacturing method according to claim 1 or 2 are stacked,
A method for manufacturing a tissue paper product, comprising a step of superposing the sanitary paper such that the second surface is an outer surface. A method for producing the tissue paper product according to claim 3 or 4 ,
A method for producing a tissue paper product, comprising a step of applying a moisturizing liquid to at least one outer surface of the tissue paper product.

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