JP2891733B2 - Wet water disintegration paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to wet disintegrated paper such as wet napkins,
More specifically, the present invention relates to a wet paper disintegrating paper which does not decompose under ordinary moisture or moist condition (wet condition) but decomposes quickly when put in a large amount of water.

[Prior Art] Conventionally, hydrolyzed papers that are easily decomposed in water are known. However, these are generally prepared using a water-soluble substance as a binder and provided as a dry product. However, due to its properties, it has been difficult to keep it stable in a wet state.

However, in recent years, water disintegration paper that is stable even in a wet state has begun to be developed. For example, a toilet seat tissue that can be used to wipe off dirt around the toilet and flow it directly to a flush toilet has been commercially available.

This hydrolyzed paper uses polyvinyl alcohol, a cellulose derivative or the like as a binder for a nonwoven fabric, and uses, as an impregnating agent, ethyl alcohol or isopropyl alcohol having low solubility in these binders at a concentration of 60% or more.

[Problems to be Solved by the Invention] However, hydrolyzed paper containing ethyl alcohol or isopropyl alcohol at a high concentration has a drawback in that the detergency for water-soluble dirt is weak and a peculiar unpleasant odor is caused during use. In addition, it is necessary to pay attention to the materials of containers and films to be packaged, and there are many disadvantages such as a requirement for high hermeticity.

Accordingly, it has been desired to provide a hydrolyzed paper capable of maintaining a wet state without using such an organic solvent.

[Means for Solving the Problems] The inventor of the present invention has conducted intensive studies in order to obtain a wet water disintegration paper based on water. And as a result, when polyvinyl alcohol is selected as the binder of the nonwoven fabric and a boron-containing solution is used as the impregnating agent, the conditions required for wet hydrolyzed paper, that is, appropriate wetness,
The present inventors have found that a water-disintegrated paper satisfying both strength and water disintegration can be obtained, and completed the present invention.

That is, the present invention provides a wet hydrolyzed paper characterized by impregnating a non-woven fabric containing polyvinyl alcohol as a binder with a boron-containing solution.

Polyvinyl alcohol as a binder of the nonwoven fabric used in the present invention may be any of fibrous, powdery and granular,
In addition, polyvinyl alcohol which is not completely converted to polyvinyl alcohol but partially unsaponified vinyl acetate may be contained.

Further, the fibers other than polyvinyl alcohol constituting the nonwoven fabric may be those having a property and a length capable of decomposing in water by dissolving polyvinyl alcohol as a binder, such as rayon, cellulose, polyamide, polyester, and polypropylene. And any of these fibers and mixtures thereof.

Content ratio of polyvinyl alcohol in nonwoven fabric, 5 to 10
0% by weight (hereinafter simply referred to as "%"), preferably 5 to 20%
%. If the content ratio of polyvinyl alcohol is less than 5%, sufficient water dissolving property cannot be obtained.

On the other hand, as a boron-containing solution as an impregnating agent, a solution in which a boron-containing compound such as boric acid or borax is dissolved in water is used. For example, when boric acid is used as the boron-containing compound, the concentration is preferably 1 to 30%, particularly preferably 1 to 8, and when borax is used, the concentration is 1 to 20%.
%, Particularly preferably 1 to 8%.

This boron-containing solution is adjusted to have a pH of 1 to 7, especially 3 to 6.
It is desirable to keep in the range of 5. For this purpose, potassium hydrogen citrate-citric acid, potassium hydrogen citrate-sodium hydroxide, trisodium citrate-citric acid, tartaric acid-sodium tartrate, lactic acid-sodium lactate, hydrogen phosphate-sodium-citric acid, etc. It is preferable to add a buffering agent so that the boron-containing solution has a buffering ability.

The amount of the boron-containing solution impregnated into the nonwoven fabric is preferably 0.5 to 10 times, more preferably 1 to 3 times the weight of the nonwoven fabric.

The wet hydrolyzed paper of the present invention is prepared by impregnating a non-woven fabric containing polyvinyl alcohol as a binder with a boron-containing solution according to a conventional method, and further optionally containing other optional components, for example, a bactericide, a surfactant, and a fragrance. , A colorant and the like may be blended and impregnated.

In addition, in order to prepare wet hydrolyzed paper having better performance, it is desirable that the above-mentioned wet hydrolyzed paper has a composite structure.

That is, as schematically shown in FIG. 1, if the outer layer wet hydrolytic paper using fibrous polyvinyl alcohol as a binder and the inner layer wet hydrolytic paper using powdery granular polyvinyl alcohol as a binder are sandwiched from both sides, ,
This is more preferable because the amount of water that can be retained is increased and the water disintegration is not reduced.

[Action] The wet hydrolyzed paper of the present invention is stable in a state of having appropriate moisture, but hydrolyzes very easily in a large amount of water.

This is presumed to be due to the following operation. That is, when the nonwoven fabric contains a suitable amount of moisture, the boric acid or the like and the hydroxyl group of polyvinyl alcohol are bonded and gelled, so that the polyvinyl alcohol is insolubilized and the nonwoven fabric does not dissolve in water.

On the other hand, when the nonwoven fabric is put in a large amount of water (discarded state), it is considered that the insolubilized state is broken by the action of a large amount of water, the polyvinyl alcohol is dissolved, and the nonwoven fabric is hydrolyzed. .

[Effects of the present invention] The wet hydrolyzed paper obtained as described above has sufficient moisture to remove dirt and the like, and is very easily hydrolyzed by being dumped in water. It can be used for wiping, cleaning, etc., evaporating paper for liquid fragrance, etc.

The wet hydrolyzable paper of the present invention does not have an unpleasant odor unlike conventional ones, and can be easily packaged, so that it is extremely practical.

EXAMPLES Next, the present invention will be described in more detail with reference to examples.

Comparative Example 1 A rayon paper (5 cm × 5 cm) containing 10% polyvinyl alcohol fiber was impregnated with boric acid aqueous solution having various concentrations and pH twice as much as that of the water, and was supplied with tap water and alkaline water (pH 8.5).
And water decomposability in acidic water (pH 4.0) were examined.

Water disintegration is 500m water in a 1 liter cylinder with an inner diameter of 65mm
l, put one test piece of 5 cm x 5 cm into it, and rotate it 180 degrees around the axis of the cylinder. This operation was carried out by setting the number of water dissolution operations to one, and observing how many times the water dissolution operation was performed to dissolve the test piece.

 Table 1 shows the results.

Comparative Example 2 A non-woven fabric containing polyvinyl alcohol (5 cm in length and width each) containing polyvinyl alcohol (45% rayon having a fiber length of 3 mm; 10% polyvinyl alcohol having a fiber length of 3 mm, and pulp 45%) was impregnated with various concentrations and amounts of boric acid water. After standing at 48 ° C. for 48 hours, tensile load and water disintegration were examined.

The water disintegration was measured in the same manner as in Comparative Example 1, but the results were represented by the number of times of water disintegration (the number of water disintegration operations in which the nonwoven fabric became two) and the number of times of water dissolution (the number of water disintegration operations in which the nonwoven fabric was completely dissolved). .

 The results are shown in Table 2.

Comparative Example 3 The same rayon paper as used in Comparative Example 1 was impregnated with a boron-containing solution containing 4% boric acid so as to be twice the weight of the rayon paper, and the change in tensile strength due to various pH was examined. .

The results are shown in FIG. 2. As is clear from the results, when the pH is about 3 to 7, the wiping properties of the surface of plastics, floors, ceramics, etc. when cleaning the surface, such as tearing, fluffing, etc. Wet strength and wet abrasion resistance are commonly referred to.

Example 1 A pulp layer was provided between two pieces of the same rayon paper used in Comparative Example 1, and the whole was embossed using a powdery polyvinyl alcohol as a binder to produce a composite hydrolytic paper. The composite hydrolytic paper was impregnated with various amounts of boric acid water to obtain a wet hydrolytic paper, and after being left at 40 ° C. for 48 hours, the tensile load and hydrolytic properties were examined.

Table 3 shows the results. The amount of boric acid water impregnated in the composite hydrolyzed paper was 1.5 times by weight, and the
Was adjusted to be 4.

Example 2 The same composite water disintegrated paper as used in Example 1 was impregnated with various concentrations of borax water, and allowed to stand at 40 ° C. for 48 hours to examine the tensile load and water disintegration. In addition, the impregnation amount of boric acid water with respect to the composite hydrolyzed paper was 1.5 times by weight, and the pH of boric acid water was adjusted to 2 to 4.

[Brief description of the drawings]

FIG. 1 is a drawing schematically showing a wet hydrolyzed paper of the present invention having a composite structure. FIG. 2 is a drawing showing the relationship between wet hydrolyzed paper pH and pulling strength.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiko Narita 1-4-10 Shimo-Ochiai, Shinjuku-ku, Tokyo Est Chemical Co., Ltd. 72) Inventor Atsushi Ishikawa 1078 Royal Mori A103, Katsube-cho, Moriyama-shi, Shiga (56) References JP-A-54-104963 (JP, A) JP-A-47-9486 (JP, A) JP-A-46- 2160 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D21H 27/00, 13/08, 13/16

Claims (5)

(57) [Claims] 1. A wet paper obtained by impregnating a water-containing paper having a nonwoven fabric containing powdery polyvinyl alcohol as a binder as an inner layer and a nonwoven fabric containing fibrous polyvinyl alcohol as a binder as an outer layer as a binder. Water disintegration paper. 2. The wet disintegrated paper according to claim 1, wherein the boron-containing solution is a solution containing boric acid or borax. 3. The wet hydrolyzed paper according to claim 1, wherein the pH of the boron-containing solution is 1 to 7 when the non-woven fabric is impregnated. 4. The wet disintegrated paper according to claim 1, wherein the content of polyvinyl alcohol in the nonwoven fabric is 5 to 100% by weight. 5. The wet hydrolyzed paper according to claim 1, wherein the non-woven fabric is impregnated with a boron-containing solution by 0.5 to 10 times by weight.