JP2005204868A - Tissue paper for household use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a tissue paper for household use and a toilet paper roll which is environment-friendly and has soft and smooth feeling. <P>SOLUTION: This sanitary paper is a single sheet or a two or more overlapped papers, and a value obtained by dividing the softness value of one sheet by the square of a basis weight is ≤0.0067 (m<SP>2</SP>)<SP>2</SP>/g. One sheet of this sanitary tissue has a basis weight of 10 to 26 g/m<SP>2</SP>, a density of 0.150 to 0.170 g/cm<SP>3</SP>, and a number of napped fibers of a ≥0.1 mm length of 1,350 to 2,350. In addition, the toilet paper roll is a single sheet or a two or more overlapped papers, its basis weight of one sheet is 15 to 31 g/m<SP>2</SP>, the density is 0.110 to 0.160 g/cm<SP>3</SP>, and the number of napped fibers of a ≥0.1 mm length is 3,500 to 4,200. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a household thin paper for sanitary thin paper (tissue paper) or toilet roll paper (toilet paper).

  As a thin paper for home use, a paper having high whiteness is generally preferred. Therefore, pulp bleached to a high degree of whiteness is used. In the manufacturing process of high whiteness pulp, chlorine-based bleaching agents such as chlorine, chlorine dioxide, sodium hypochlorite and the like are usually used.

  On the other hand, household thin paper is required to be soft, feel good, strong, stretchable, and excellent in absorption (water absorption).

  Conventionally, this type of household thin paper pulp is usually produced from hardwood, softwood wood chips, ie, chemical pulp obtained by digesting lignocellulosic material.

  In order to maintain the strength of home thin paper, especially the tensile strength, softwood pulp having a long average fiber length and high tensile strength is used. However, softwood pulp is rigid, so when used alone, the softness and feel of hand are reduced. On the other hand, hardwood pulp is thin, supple and soft and feels good, but it is rarely used alone as a pulp for household thin paper because of its short average fiber length and low tensile strength. Therefore, in order not to deteriorate the softness and touch feeling while maintaining the tensile strength, a method of using coniferous pulp and hardwood pulp in combination is common. In addition, methods for adding various softening agents are known.

  However, it has been found that there is a limit in improving softness and smoothness as long as a chlorine bleach is used for high whiteness bleaching.

In addition, it is thought that organic chlorine compounds such as dioxins are generated in the bleaching process using chlorine-based bleaching agents, and with the recent increase in environmental awareness, the use or reduction of their use is required. .
JP 2003-219978 A

  The problems to be solved are mainly to reduce the use of chlorinated bleach as much as possible, consider the environment, and obtain household thin paper with a soft and smooth texture.

The present invention is as follows.
<Invention of Claim 1>
One or two or more stacked sheets, and the value of one sheet of softness divided by the square of the rice square is 0.0067 (m ² ) ² / g or less. Tissue paper.

<Invention of Claim 2>
Fluffing of one sheet or two or more sheets, having a basis weight of 10 to 26 g / m ² , a density of 0.150 to 0.170 g / cm ³ , and a length of 0.1 mm or more The sanitary thin paper according to claim 1, wherein the number of fibers is 1350 to 2350.

<Invention of Claim 3>
The sanitary thin paper according to claim 1 or 2, wherein an ECF bleached pulp and / or a TCF bleached pulp not using a chlorine compound for bleaching is contained in an amount of 55 to 100% in the whole pulp.

<Invention of Claim 4>
4. The sanitary thin paper according to any one of claims 1 to 3, wherein a value obtained by dividing the softness value of one sheet by the square of the rice tsubo is 0.0055 to 0.0065 (m ² ) ² / g. .

<Invention of Claim 5>
One piece or a stack of two or more pieces, with a basis weight of 15 to 31 g / m ² , a density of 0.110 to 0.160 g / cm ³ , and fluff having a length of 0.1 mm or more The roll of toilet roll paper according to claim 1, wherein the number of fibers is 3500-4200.

<Invention of Claim 6>
The roll-up roll paper for toilets according to claim 1 or 5, wherein ECF bleached pulp and / or TCF bleached pulp not using a chlorine compound for bleaching is contained in an amount of 60 to 100% in the total pulp.

<Invention of Claim 7>
The toilet according to any one of claims 1 and 5 to 6, wherein the value of softness per sheet divided by the square of the rice square is 0.0050 to 0.0067 (m ² ) ² / g. Winding roll paper.

  The thin paper for household use according to the present invention has a soft and smooth texture, and further reduces the amount of pulp that uses a chlorine bleach for high whiteness bleaching as much as possible. Therefore, it is environmentally friendly.

When the present invention is intended for sanitary thin paper, it is one sheet or a stack of two or more sheets, and a value obtained by dividing the value of one sheet of softness by the square of US tsubo is 0.0067 (m ² ) ² / g or less. Further, there are one sheet (one ply) or two sheets (two plies) or more. The basis weight of one sheet is 10 to 26 g / m ² , the density is 0.150 to 0.170 g / cm ³ , and the number of fluffed fibers having a length of 0.1 mm or more is 1350 to 2350. It is characterized by.

  The density value of the sanitary thin paper according to the present invention means that it is smaller than a conventionally known one or a commercially available product, is bulky, fluffy as a texture, or soft. When the value of density is high, it becomes hard and stiff, and the softness and softness are not sufficient. Further, when the density is smaller than the value of the present invention, there is a problem that the paper strength is reduced and the durability is impaired.

  In addition, the number of fluffed fibers having a length of 0.1 mm or more of the sanitary thin paper according to the present invention means that it is softer than that conventionally known or commercially available. When the number of fluffy fibers is excessively large, paper dust is generated. On the other hand, if the number of fluffed fibers is less than the value of the present invention, the paper becomes hard, and the paper is particularly rough.

  In the present invention, “the number of fluffed fibers having a length of 0.1 mm or more” can be measured by a fiber rising tester (manufactured by Matsubo).

  On the other hand, in the present invention, ECF (elementary chlorin-free) bleached pulp and / or TCF (total chlorin-free) bleached pulp that does not use a chlorine compound for bleaching are used. As the ratio, ECF (elementary chlorin-free) bleached pulp and / or TCF (total chlorin-free) bleached pulp in the total pulp is 55 to 100%, more desirably 70 to 100%, and particularly preferably 90%. It is desirable to contain ~ 100%.

  As the pulp used in the present invention, it is desirable to use pulps such as LBKP, NBKP, LBSP, NBSP, TMP, CTMP, BCTMP, GP and RGP used for general papermaking pulp. In particular, LBKP and NBKP are used, and the weight ratio (N / L ratio) of NBKP / LBKP is preferably 20/80 to 70/30. When the N / L ratio is small, the strength tends to be insufficient. When the N / L ratio is excessively large, the strength is increased and the strength is hard and stiff.

  If necessary, various waste paper pulps, particularly waste paper pulp using non-chlorine bleach such as hydrogen peroxide as a bleaching agent, are mixed in a ratio of 30 parts by weight or less to 100 parts by weight of ECF bleaching or TCF bleaching pulp. be able to.

  The present inventor has obtained the following knowledge. That is, the chlorine bleached pulp fibers are easily damaged, and if the beating load is increased to produce paper strength and the fibers are fibrillated, the paper becomes hard and it is difficult to obtain the soft texture of household thin paper. When a large amount of softening agent is mixed as a solution when the paper becomes hard, the paper strength decreases, and problems such as easy tearing occur. In contrast, according to the present invention, the use of chlorine bleached pulp is suppressed as much as possible, that is, when ECF bleached pulp and / or TCF bleached pulp that does not use a chlorine compound for bleaching is used, the fiber is less damaged and the beating load is reduced. Even with a small or normal beating load, sufficient paper strength is obtained and the fibers are not damaged, so the gap is large, hard to crush, soft, fluffy surface, high water absorption, no softener is used, or Even with the addition of a small amount of softening agent, it is possible to obtain household soft tissue with a soft texture.

According to the present invention, a value obtained by dividing the softness value of one sheet by the square of the rice tsubo is 0.0055 to 0.0065 (m ² ) ² / g smaller than that conventionally known or commercially available. Can be obtained with a soft value.

  Other conditions for obtaining the above sanitary thin paper are an extension of the skill of those skilled in the art. For example, the tissue paper can be obtained by selecting various manufacturing conditions. By the way, the type of pulp (fiber roughness, or the type and age of the tree used as raw material), beating degree (beating load, especially refiner gap adjustment), papermaking moisture, calendar gap / pressure / material, addition of surfactant and It is possible to adjust by the amount. In particular, when the beating load is increased, the fiber becomes more fibrillated, but at the same time, the fiber is damaged. The beating load is preferably about 10% lower than when ECF bleaching or TCF bleached pulp is not used.

  The softness can be adjusted by adjusting the tensile strength, aspect ratio, crepe shape (crepe rate, crepe height difference, etc.), moisture content, density, addition of paper strength agent, addition of surfactant, and its amount. is there. Smoothness can be adjusted by pulp blending, calendering conditions, papermaking moisture, doctor blade edge angle, blade angle, balance of adhesion / peeling strength, crepe rate, addition of surfactant and amount thereof.

  In the present invention, cellulose pulp can be obtained by digesting wood. As the cooking method, various cooking methods such as kraft cooking can be used. In addition to the kraft cooking method, known cooking methods such as polysulfide cooking, soda cooking, and alkali sulfite cooking can be used. In recent technology related to chlorine-free bleaching, unbleached pulp is bleached with alkaline oxygen and then delignified by hydrogen peroxide treatment in the acidic region, etc., and the load in the subsequent bleaching process is reduced to reduce pulp fiber damage. It is common to control or reduce the basic unit of bleaching chemicals.

ECF pulp, after the acid treatment in an acidic region, for example in a multi column bleached _{A-Z / D-E O} -P-D, A-Z / D-E O -W-D- in substitution bleached Although D etc. are used, it is not limited to these, D-E-D, D-E _O- D, D-E _OP- D, D-E _OP- DnD, D-E-D-E Examples such as -D, D-E _OP -D- _ED are known.

The TCF pulp, after the acid treatment in an acidic region, Z-E-P, Z -E O -P, examples of such E _OP -P _O is known.

  Yankee machines such as circular nets, short nets, and twin wires can be used as the paper machine. A tissue paper is obtained by applying wet crepe or dry crepe on a Yankee dryer, or by applying wet crepe and then applying dry crepe. In the case of a tissue paper or the like in a box, the tissue paper is manufactured by stacking two sheets and processing them with a calendar usually made of a pair of upper and lower metal rolls.

  As a papermaking method, any of a conventional papermaking method in which all pulps are mixed to form a uniform layer, and a papermaking method in which two or more layers, which are so-called laminated tissue papers, are combined to form one sheet are applied. However, the latter papermaking method is more preferable.

  In the present invention, various softening agents can be added. Examples thereof include fatty acid ester softeners (US Pat. No. 3,296,065), quaternary ammonium salt type cationic activators (Japanese Patent Laid-Open No. 48-22701), urethane alcohols or salts thereof, or Cationized products (Japanese Patent Laid-Open No. 60-139897), non-cationic surfactants (Japanese Patent Laid-Open Nos. 2-99690 and 2-99691), polyphosphates (Japanese Patent Laid-Open No. 2-36288), Polysiloxane (JP-A-2-224626, JP-A-3-900) and the like. The amount of the softening agent added is desirably 5.0 kg or less per ton of paper stock.

Thus, according to the present invention, one sheet or a stack of two or more sheets, the basis weight of one sheet is 10 to 26 g / m ² , and the density is 0.150 to 0.170 g / cm ³ , A sanitary thin paper having 1350 to 2350 fluffy fibers having a length of 0.1 mm or more is provided.

  And the sanitary thin paper in which the ECF bleached pulp which does not use a chlorine compound for bleaching and / or TCF bleached pulp contains 55-100% in all the pulp is provided.

On the other hand, the roll-up roll paper for toilets of the present invention is one or two or more stacked from the viewpoint that the required quality differs from the case of sanitary thin paper, and the basis weight of one sheet is 15 to There are provided 31 g / m ² , a density of 0.110 to 0.160 g / cm ³ , and 3500 to 4200 fluffed fibers having a length of 0.1 mm or more.

  Moreover, the roll-up roll paper for toilets which ECF bleached pulp and / or TCF bleached pulp which does not use a chlorine compound for bleaching contains 60 to 100% in all the pulp is provided.

In the roll of toilet roll paper, it is desirable that the value of the softness of one sheet divided by the square of the rice square is 0.0050 to 0.0067 (m ² ) ² / g.

The effects of the present invention will be specifically described below with reference to examples and comparative examples.
Evaluations and evaluation methods performed on the tissue paper obtained in each example and comparative example are as follows.
1. Softness: J.H. TAPPI Paper Pulp Test Method No. 34-80. It was measured by the softness test method of sanitary thin paper. That is, the amount of work required to push a test sheet (100 × 100 mm) into a certain gap (5.0 mm) is measured by a Handle-O-Meter, and the average measured values in the vertical and horizontal directions are measured in g / 100 mm. Displayed.
2. 2. Beating load: electrical load when pulp raw material is fibrillated with a double disc refiner Freeness: According to the Canadian standard drainage test method stipulated in JIS P8121, the actual use evaluation and sensory evaluation were conducted for 50 adults with “feel good when touching nose” (smoothness), “soft thickness” For each item, the best score: 5 points, good score: 4 points, normal score: 3 points, bad score: 2 points, worst score: 1 point was evaluated on a 5-point scale, and the average score was 4.0. The above is represented as ◎, 3.0 to less than 4.0 as ◯, 2.0 to less than 3.0 as Δ, and 1.0 to less than 2.0 ×.
4). The paper thickness at the time of calculating the density was measured with a thickness gauge.

(Example 1)
As the raw material pulp, commercial pulp NBKP and its own product LBKP were blended in an absolutely dry amount of 30:70 and adjusted to a freeness of 670 ml (CSF). In addition, as an own product LBKP, two types of ECF pulp and chlorine bleached pulp are used, and ECF's own product LBKP is acid-treated with sulfuric acid after alkaline oxygen delignification treatment, and AZ / D-E _O -Used pulp with whiteness of 86% bleached in the bleaching process of P-D, and the bleached product LBKP of chlorine bleaching was bleached in the bleaching process of C-E _O -HD after alkaline oxygen delignification treatment Pulp with a whiteness of 86% was used.

A wet paper strength enhancer (polyamide polyamine epichlorohydrin resin) is added to each raw pulp at 0.5% by weight per mass of dry pulp, and then the papermaking system is such that the extraction pH of the resulting tissue paper is 6.6. After adjusting the pH of the solution with a sodium hydroxide solution, paper was made with a round net type Yankee paper machine to produce tissue paper having a basis weight of 12.6 g / m ² . The obtained tissue paper is peeled off from the dryer surface by a creping doctor, and a 17% dry crepe is applied by providing a speed difference from the take-up reel, and then the layer in contact with the mirror surface of the Yankee dryer is placed outside. A tissue paper was manufactured by stacking two sheets.

(Examples 2 to 4)
The blending ratios of NBKP, LBKP, and ECF (TCF) pulp were changed as shown in Table 1, and the others were manufactured in substantially the same manner as in Example 1. Table 1 shows some changes in freeness and rice basis weight.

(Comparative Examples 1-4)
As shown in Table 1, commercially available pulp NBKP and its own product LBKP were blended in an absolute dry amount of 25-50: 75-50 as shown in Table 1, and the freeness was adjusted to 650-670 ml (CSF). The self-produced LBKP used was chlorine-bleached self-produced LBKP, and a pulp having a whiteness of 86% bleached in the bleaching step of C-E _O -HD after alkaline oxygen delignification was used. Thereafter, the same weight as in Example 1 was produced with a rice tsubo of 12.2 to 24.7 g / m ² .

(Example 5)
As raw material pulp, commercial pulp NBKP and its own product LBKP were blended in an absolutely dry amount of 30:70, and the freeness was adjusted to 680 ml (CSF). In addition, as the own product LBKP, two types of ECF pulp and chlorine bleached pulp were used, and as in Example 1, ECF's own product LBKP was subjected to acid treatment using sulfuric acid after alkaline oxygen delignification treatment, and A- Using a pulp with a whiteness of 86% bleached in the bleaching step of Z / D-E _O -P-D, the chlorine-bleached product LBKP is C-E _O -H-D after alkaline oxygen delignification treatment. The pulp having a whiteness of 86% that was bleached in the bleaching process of No. 1 was used.

Each raw pulp was made with a round net type Yankee paper machine to make a toilet roll having a basis weight of 17.1 g / m ² . The obtained toilet roll was peeled off from the dryer surface by a creping doctor, a 22% dry crepe was applied by providing a speed difference with the take-up reel, and then a toilet roll was manufactured by stacking two sheets.

(Examples 6 to 8)
The blending ratios of NBKP, LBKP, and ECF (TCF) pulp were changed as shown in Table 2, and the others were manufactured in substantially the same manner as in Example 5.

(Comparative Examples 5-7)
As raw material pulp, NBKP of commercial pulp and LBKP of its own product were blended in an absolutely dry amount of 30 to 55:70 to 45, and adjusted to freeness of 670 to 691 ml (CSF). The self-produced LBKP used was chlorine-bleached self-produced LBKP, and a pulp having a whiteness of 86% bleached in the bleaching step of C-E _O -HD after alkaline oxygen delignification was used. Thereafter it was prepared in the same manner as in Example 5 was basis weight and 16.8~29.0g / m ^2.

<Discussion>
Since the products according to the examples of the present invention are sufficiently evaluated in any actual use evaluation and sensory evaluation items in comparison with the commercial products, the products according to the examples of the present invention are distinguished. The chemical structure is clear and shows superior characteristics compared to the commercial products.

Claims (7)

One or two or more stacked sheets, and the value of one sheet of softness divided by the square of the rice square is 0.0067 (m ² ) ² / g or less. Tissue paper. Fluffing of one sheet or two or more sheets, having a basis weight of 10 to 26 g / m ² , a density of 0.150 to 0.170 g / cm ³ , and a length of 0.1 mm or more The sanitary thin paper according to claim 1, wherein the number of fibers is 1350 to 2350.   The sanitary thin paper according to claim 1 or 2, wherein an ECF bleached pulp and / or a TCF bleached pulp not using a chlorine compound for bleaching is contained in an amount of 55 to 100% in the whole pulp. 4. The sanitary thin paper according to any one of claims 1 to 3, wherein a value obtained by dividing the softness value of one sheet by the square of the rice tsubo is 0.0055 to 0.0065 (m ² ) ² / g. . One piece or a stack of two or more pieces, with a basis weight of 15 to 31 g / m ² , a density of 0.110 to 0.160 g / cm ³ , and fluff having a length of 0.1 mm or more The roll of toilet roll paper according to claim 1, wherein the number of fibers is 3500-4200.   The roll-up roll paper for toilets according to claim 1 or 5, wherein ECF bleached pulp and / or TCF bleached pulp not using a chlorine compound for bleaching is contained in an amount of 60 to 100% in the total pulp. The toilet according to any one of claims 1 and 5 to 6, wherein the value of softness per sheet divided by the square of the rice square is 0.0050 to 0.0067 (m ² ) ² / g. Winding roll paper.