JPH03185197A - Tissue paper excellent in dispersion in water - Google Patents

Abstract

PURPOSE:To obtain the subject tissue paper free from a fault in use such as breaks or holes and having a tensile strength equal to that of a box tissue without damage to formation, touch, etc., by adding a weakly cationic dialdehydestarch to a raw pulp and subsequently carrying out papermaking thereof. CONSTITUTION:A raw pulp is charged in a beater and treated using a refiner and a weakly cationic dialdehydestarch is subsequently added thereto in an amount of 0.1-0.4% based on the raw pulp followed by sufficient mixing. The resultant mixture is then subjected to papermaking using a jet former type tissue papermaking machine, etc., in conditions of 140cm paper width, 200m/min paper speed and 20% crepe ratio, thus obtaining the objective tissue paper having 12.5-16.5g/m<2> weight, excellent in tensile strength and dispersion in water and capable of throwing into a water closet.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to tissue paper that has excellent tensile strength and water dispersibility.

(Conventional technology) Tissue paper is made from bleached chemical pulp as the main raw material.
It is a two-ply tissue paper that has been given wet strength so that it does not tear even when it gets wet, and can be divided into boxed tissues, pocket tissues, toilet tissues, towel tissues, etc. For boxed tissues, JIS S310
4-1985 specifies the qualities of basis weight, tensile strength, water absorption, whiteness, and fluorescence, and requires a certain tensile strength (80 gf in the transverse direction when dry and 60 gf in the longitudinal direction when wet).

(Problem to be solved by the invention) Since toilet tissue requires water dispersibility, it is not possible to use a paper strength enhancer, so the lack of strength can be compensated for by increasing the beating degree or basis weight. However, the disadvantages are that it has a poor texture, contains a lot of paper dust, and is extremely weak in water resistance compared to boxed tissues.

In addition, wet paper strength agents are used in boxed tissues, pocket tissues, and towel tissues to give them strength, so while their wet strength is strong, they have poor water dispersibility, so they cannot be flushed down the flush toilet. Pocket tissue, in particular, usually has a tensile strength close to that of boxed tissues, or generally has a strength greater than that of boxed tissues to improve processability.

Such strong tissues, such as pocket tissues, are sometimes used in toilets that are not equipped with toilet paper, causing problems such as clogging of flush toilet piping and difficulty dispersing in septic tanks.

(Means for Solving the Problems) The present invention solves the above-mentioned conventional problems, and provides a tissue that has tensile strength like a boxed tissue and has good water dispersibility like a toilet tissue. The purpose is to provide.

In other words, the tissue of the present invention is a tissue paper with good water dispersibility obtained by adding weakly cationic dialdehyde starch to the raw material pulp and then making the paper. There is a relationship;
- Although it cannot be determined generally, for example, when the basis weight of tissue paper is 12.5 to 16.5 g/m'', the amount of weakly cationic dialdehyde starch added to the raw material pulp is determined by solid substitution #0. , 1%, 0, 4%, a tissue with good strength and water dispersibility can be obtained.

The weakly cationic dialdehyde starch used in the present invention is commercially available, but it can be produced, for example, as follows.

Water is put into the dissolution tank, the pH is adjusted to 4-5, and the temperature is raised to 85°C. Add dialdehyde starch to this and dissolve while heating and stirring. Concentrated hydrochloric acid was added to the resulting solution to adjust the pH to 3. Ofo, 5, then cooled to 30°C by water cooling. Add a cationizing agent (e.g., cationic acrylic vinyl acetate copolymer resin) and dilute to about 10% with water to form a weak cationic dialdehyde. Obtain an aqueous solution of starch.

(Example) Next, the effects of the present invention will be explained using Examples and Comparative Examples.

340 kg of bone-dry NBKP (Lavonia: Finnish coniferous valve) was placed in a beater, treated with a refiner to obtain a softness of 14"SR, and then a weakly cationic dialdehyde starch [Tonepal, manufactured by Nippon Carlit Co., Ltd.] was added. ] was added.

The amount added is 0.05%, 0.05% in terms of solid content, based on the valve.
There were six types: 1%, 0.2%, 0.3%, 0.4% and 0.5%. After the addition, mix well and then manufacture tissue paper using a jet former type tissue paper machine under the conditions of paper width 140 cm, paper speed 200 m/min, crepe rate 20%, and the basis weight shown in Table 1. Got tissue paper.

In addition, under the same manufacturing conditions as above, one without adding weak cationic dialdehyde starch and a commercially available epoxy resin paper strength agent (Kaimen 557H, manufactured by Dick Vercules) were added to the pulp in terms of solid content. 0.2% was added to obtain tissues having the basis weight shown in Table 1.

The tensile strength and water dispersibility of the tissue obtained as described above are shown in Table 1 together with the performance of commercially available tissues.

The test methods for tensile strength and water dispersibility are as follows.

[Tensile strength test] (JIS 53104-1985
(according to the above) When dry: Two test pieces are stacked (- set) and pulled in the horizontal direction of the paper (perpendicular direction to the paper flow during paper making).
The width was 25 mm, and the grip interval was 100 mm.

When wet: The test piece was attached to a measuring machine so as to be pulled in the longitudinal direction of the paper (the paper flow direction during paper making), the test piece was moistened with water, and the measurement was carried out in the same manner as when dry.

[Water dispersibility test] 0.5 g of the test piece was placed in a 500 mQ Erlenmeyer flask with a stopper containing 250 mQ of water, and the dispersion state was observed after shaking at a speed of 200 times per minute (stroke width 40 mm). did. In Table 1, ◯ indicates that the paper has been completely pulped, Δ indicates that it has been loosened into pieces and is on the verge of becoming pulp, and × indicates that it is still in the paper state.

Table 1 shows that the tissue paper of the present invention has the same initial wet strength as commercially available boxed tissue or pocket tissue, but has the property of gradually losing strength in water.

In addition, the tissues from Experimental Parts 3 to 6 were continuously used in flush toilets for one week, and when the inside of the septic tank was observed after 7 days, the tissues were completely turned into valves due to the convection effect caused by aeration, and the pipes were not clogged.

(Effects of the Invention) The tissue of the present invention does not impair its texture, texture, etc., has no defects in use such as tears or holes, has strength comparable to boxed tissues, and has excellent water dispersibility, so it can be washed with water. A useful tissue that can be flushed down the toilet.

Claims (1)

[Claims] 1. Tissue paper with good water dispersibility obtained by adding weakly cationic dialdehyde starch to raw material pulp and then making paper. 2 The basis weight of tissue paper is 12.5 to 16.5 g/
The tissue paper according to claim 1, wherein the amount of weak cationic dialdehyde starch added is 0.1 to 0.4% based on the raw material pulp when m^2.