JPH0598597A - Tissue paper - Google Patents

Abstract

PURPOSE:To provide tissue paper excellent in the flexibility, hand touch, strength, elasticity and absorbability and useful for make-up, etc., by employing specific pulp. CONSTITUTION:In tissue paper produced from pulp fibers as a main raw material, the pulp fibers having a curl factor of 2.5-4.0 in a 150 mesh fraction in the sieving test (JIS P-8207) for the pulp are employed to provide the objective tissue pulp.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to tissue paper. More specifically, it relates to a tissue paper excellent in softness and feel. More specifically, it relates to tissue paper using pulp fibers having a specific curl factor.

[0002]

2. Description of the Related Art As is well known, it is desired that the tissue paper for cosmetics, toilet tissue, towels, etc. is soft, has a good feeling to the touch, has a high strength, is stretchable, and has excellent absorbency. ing.

[0003] Conventionally, as a pulp for tissue paper, slush pulp in a slurry state produced from hardwood or softwood wood chips, that is, pulp obtained by digesting a lignocellulosic material.
p), dry pulp obtained by dehydrating and drying this slush pulp (dry pulp), and deinking treated pulp obtained by deinking used paper are used, and these pulps are unbleached and bleached pulps. In the state of, or in the state of unbeaten or beaten pulp, it is used alone or in a mixture depending on the quality design.

For these pulps, a paper making machine such as a long wire, short wire, twin wire, cylinder Yankee machine or the like is appropriately selected, or a softening agent for paper, for example, a fatty acid ester softening agent (US Pat. 296,065), quaternary ammonium salt type cation activator (JP-A-48-22701), urethane alcohol and its salts,
Or a cationized compound (JP-A-60-139897),
Non-cationic surfactant (JP-A-2-99690, JP-A-2-99691), polyphosphate (JP-A-2-3)
6288), polysiloxane (JP-A-2-22462).
No. 6, JP-A-3-900) has been proposed to add various chemicals to slush pulp to improve the slip of the slush pulp itself and to improve the touch, thereby making it soft.

Although these methods may obtain a good softening effect in some cases, since they have a large foaming property, they may hinder the papermaking operation itself, and in some cases, they have paper strength and water absorbency. However, there is a problem in that

[0006]

In view of the above situation, the inventors of the present invention have diligently studied the problems in the production of tissue paper which is soft and has a good feeling to the touch, and as a result, the curl of pulp fiber used in the tissue paper has been found. That the softness and touch feel differ depending on the degree, that is, the curl factor for 150 mesh on in the pulp fiber sieving test (JIS P 8207) is 2.5.
The present invention has been completed by knowing that a tissue paper excellent in softness and hand feeling can be obtained when a pulp fiber having a weight ratio of up to 4.0 is used.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a tissue paper produced by using pulp fiber as a main raw material, and the curl factor of 150 mesh-on in a sieving test (JIS P 8207) of the pulp fiber is 2.5.
It is a tissue paper characterized by using the pulp fiber which is -4.0.

The definition of curl factor and its measuring method are as follows. 5) Definition The curl factor is defined as the ratio (ML / BD) between the maximum width BD and the maximum length ML shown in FIG. 1 for one pulp fiber.

2) Measuring method (1) Pretreatment of pulp (1) After disaggregation (concentration about 2%, 5 minutes) with a disintegrator, fiber fraction pulp of 150 mesh or more is collected by a sieving tester. (2) The fiber pulp is diluted to a concentration of about 0.01%.

(2) Preparation of preparation (1) 3 on a bronze wire of a round type hand sheet machine
Cover with a 00 mesh nylon wire so that it does not wrinkle, and cover with water. (2) About 3 cc (BD about 0.
3 mg), and after stirring in the usual manner for hand-making, water is poured to disperse the pulp fibers on the nylon wire. The pulp used at this time is extremely small, so be careful when washing. (3) Peel up the nylon wire from the bronze wire and spread it on No.26 filter paper (3 sheets). (4) Slide glass on nylon wire (76mm x
26mm, 4-5 pieces of edge polishing) are placed side by side near the center. At this time, be careful not to slide the pulp fiber. (5) Put No. 26 filter paper (three sheets) on the slide glass and wet press the whole. (Pressing pressure 1kg / c
(m ² , about 1 minute) (6) After pressing, the whole is placed inside out and the nylon wire is gently peeled off, and the dispersed fiber is transferred onto the slide glass.

(3) Measurement of curl factor (1) A transmitted light image (15 times) of a stereoscopic microscope is used as an image analyzer Luzex III (IMAGE PROCESS manufactured by Nireco Co., Ltd.)
OR ANALYZER). (2) The following image processing is performed on Luzex. -If there is uneven irradiation during binarization, shading correction is performed.・ If there are crossed fibers, cut them, move them, and restore them. Remove areas below 150 points, vessels, and clearly non-fiber images. (3) By the Luzex parameter [ML / BD],
The measurement is performed for 300 or more fibers.

The pulp used in the present invention is a pulp obtained by digesting a lignocellulosic material with an alkaline cooking chemical (hereinafter referred to as alkaline digested pulp).
And / or deinked waste paper pulp (DIP) is used. Examples of the alkaline cooking pulp include kraft pulp (cooking solution, NaOH + Na ₂ S), polysulfide pulp (cooking solution, NaOH + Na ₂ Sx), soda pulp (cooking solution, NaOH), alkaline sulfite pulp (cooking solution, NaOH + Na ₂ SO _3). ), Sodium carbonate pulp (cooking liquor, Na ₂ CO ₃ ) and oxygen-soda pulp (cooking liquor, O ₂ + NaOH).

These pulps are prepared by adding a cyclic keto compound (eg anthraquinone,
1,4-dihydro-9,10-diketoanthracene) may be added for cooking.

A suitable kraft method pulp is suitable as the above alkaline cooking pulp. This kraft method pulp is a so-called modified alkaline cooking method comprising divided addition of cooking liquor and cocurrent and countercurrent cooking in a digester. It may be a pulp obtained by (MCC method, Modified Continuous Cooking). These pulps may be used alone or in a mixture in an unbleached pulp, a bleached pulp state, or an unbeaten or beaten pulp state.

As the deinking treated pulp, fine paper type electronic copying paper, business form paper waste paper, so-called OA
Pulp obtained by deinking used paper is preferable, and these alkaline digested pulp and deinked pulp may be used alone or in combination, and conventional slush pulp, dry pulp and DIP are blended. Good.

As the lignocellulosic material used as the raw material of the alkaline digested pulp of the present invention, wood-based cellulosic materials such as softwood chips, hardwood chips and sawdust, and non-wood-based cellulosic materials such as bagasse, kenaf, straw, reed, esparto, etc. The annual plant can be exemplified.

The above-mentioned slush pulp, NBKP, L
The curl factor for 150 mesh-on in a sieving test for commonly used pulp such as BKP is about 4.5 to 5.5. That is, the conventional tissue paper is manufactured by using pulp fibers having a curl factor of about 4.5 to 5.5. On the other hand, the curl factor for 150 mesh on in the sieving test of the pulp fiber of the present invention is in the range of 2.5 to 4.0. When it is higher than this range, the degree of curl of the fiber is low and the softness is not so improved. On the other hand, when the curl factor is 2.5 or less, the degree of curling is large, the texture of the tissue paper is deteriorated, and the strength is lowered.

The curl factor of the present invention is 2.5 to 4.
As a means for setting the range of 0, a method of performing mechanical kneading treatment while applying compressive force to the dehydrated pulp already proposed by the present inventors (Japanese Patent Application No. 3-207136), that is, a refiner, a screw press, It can also be prepared by performing mechanical treatment while applying a compressive force by at least one means selected from a kneader, a twin-screw mixer, a disperser and the like.

Any other commercially available dry pulp may be used, as long as it has undergone keratinization, kinking, etc. and has a curl factor within the range of the present invention.

With respect to the curled pulp, all the pulp used as the tissue paper raw material may be curled, or a part of the pulp fibers, for example, only softwood bleached kraft pulp or only hardwood bleached kraft pulp may be processed. However, the curl factor is 2.5 to 4.
It may be in the range of 0.

[0021]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not of course limited to these. The parts and% in the examples and comparative examples are parts by weight and% by weight, unless otherwise specified.

The evaluation methods used in the following examples and comparative examples are as follows.

Measurement of Tensile Strength (Longitudinal) Two-ply tissue paper is cut into a width of 25 mm parallel to the flow direction (longitudinal direction), and the length of 100 mm is cut into tensilon universal tensile tester (Toyo Bold-in ( Manufactured by K.K.) and measure the breaking strength.

○ Softness measurement method (J. JAPPI paper pulp test method No. 34 to 80, softness test method for sanitary thin paper) A tissue paper sheet (200 × 200 mm) is placed in a fixed gap (6.35 mm). Multiply the value measured by the handle auto meter (made by Kumagai Riki Kogyo Co., Ltd.), which measures the amount of work required to push it in, by 0.5, and the unit is g / 10 cm.
And The test piece is pushed in by bending it at right angles to the flow direction of the sample.

Sense of touch Feeling was evaluated by 5 males and 5 females, and displayed in the following categories. Very good; ◎ Good; ○ Normal; △ Inferior; ×

Example 1 Hardwood bleached kraft pulp mainly composed of beech and eucalyptus (freeness 530 mlC. SF, 150 mesh on 8
7%) and red pine, Douglas fir bleached softwood kraft pulp (freeness 575mlC. SF, 15
0 mesh on 93%) was mixed at a ratio of 50% and 50%, and a pulp having a pulp concentration of 3.0% was sent to a screw press (V-45 type manufactured by Aikawa Tekko Co., Ltd.) to be dehydrated to a pulp concentration of 35%. Disperser (Aikawa Iron Works, TL-2
Type) was used to perform a kneading treatment at 80 ° C. for 6 minutes while applying a compressive force at a pulp concentration of 35% to dilute it to 3.0% to disperse the pulp fibers. The curl factor of this pulp was 2.6 and it was 150 mesh on 85%.

A wet paper strength enhancer, Kaimen K-, is added to this raw material.
1300 (manufactured by Dick Hercules Co., Ltd.) against pulp.
10% was added and the paper was made with a twin wire type Yankee paper machine. As for the crepe, a dry crepe was applied by taking the speed difference between the dryer and the take-up reel. The basis weight of the tissue paper made is 13.5 g / m.
Adjusted to ² .

Two sheets of this tissue paper base paper were stacked so that the surface (dryer surface) was on the outside, and a soft calender was applied in two stages. This soft calender is an elastic roll with urethane rubber coating on the upper side of the two rolls.
Shore D hardness was 90 degrees, the lower roll was a metal roll, and the linear pressure at that time was 7.0 kg / cm.
The results are shown in Table 1. The tensile strength (longitudinal) of the two-ply tissue paper was 410 g, the softness was low at 3.7 g / 10 cm, and the touch feeling was good.

Examples 2, 3, 4 Tissue paper was produced under the same conditions as in Example 1, except that the kneading time of the disperser was changed to 4 minutes, 3 minutes and 2 minutes. The obtained pulp has a curl factor of 3.1,
It was 3.4 and 3.9. The results are shown in Table 1.

Comparative Example 1 A tissue paper was produced under the same conditions as in Example 1 except that the kneading time of the disperser was 10 minutes. The curl factor of the obtained pulp was 2.3. The tensile strength (longitudinal) of the paper was as weak as 370 g, and the paper was broken during the calendering process. The results are shown in Table 1.

Comparative Example 2 A tissue paper was produced under the same conditions as in Example 1 except that the pulp concentration during the disperser kneading treatment was 20% and the treatment time was 5 minutes. The results are shown in Table 1.

Comparative Example 3 A tissue paper was produced under the same conditions as in Example 1 except that the pulp concentration during the disperser kneading treatment was 20% and the treatment time was 2 minutes. The results are shown in Table 1.

Comparative Example 4 A tissue paper was produced under the same conditions as in Example 1 except that the dehydration treatment and the disperser treatment were not performed. The results are shown in Table 1.

[0034]

[Table 1]

[0035]

Industrial Applicability As described above, the pulp fiber according to the present invention has a curl factor of 2.5 to 4.0 for 150 mesh-on in the pulp fiber sieving test specified in JIS P 8207. The tissue paper used is a soft and comfortable tissue paper.

[0036]

[Brief description of drawings]

FIG. 1 is a diagram for explaining a curl factor of pulp fiber.

[Explanation of symbols]

1 ... Curled pulp fiber, BD ... Maximum width of curled pulp fiber, ML ... Maximum length of curled pulp

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location D21H 15/00 (72) Inventor Tsutomu Horikoshi 1 Ojimachi, Kasugai, Aichi Prefecture Kasugai Co., Ltd. in the factory

Claims (1)

[Claims] 1. A tissue paper produced using pulp fibers as a main raw material, wherein pulp fibers having a curl factor of 2.5 to 4.0 for 150 mesh-on in a sieving test of the pulp fibers (according to JIS P 8207) are used. A tissue paper characterized by being used.