JPH03213596A - Wet hydrolyzable paper - Google Patents

Abstract

PURPOSE:To obtain hydrolyzable paper useful for clean wiping in toilet, cleaning, volatile paper for liquid paper, etc., having enough wetness to remove stain, etc., readily hydrolyzing by impregnating nonwoven fabric containing PVA as a binder with a boron-containing solution. CONSTITUTION:Nonwoven fabric containing PVA as a binder is impregnated with a boron-containing solution (preferably one containing boric acid or borax and having pH 1-7 in an impregnated state of nonwoven fabric) to give the objective hydrolyzable paper. The content of PVA in the nonwoven fabric is preferably 5-100wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to wet ice-breaking paper such as wet napkins, and more particularly to wet ice-breaking paper such as wet napkins, and more particularly,
It relates to wet water-disintegrable paper that does not decompose in a wet state, but quickly decomposes when placed in a large amount of water.

[Prior Art] Water-disintegrable papers that are easily decomposed in water have been known, but these are generally prepared using water-soluble substances as a binder and are not provided as dry products. However, due to its nature, it was difficult to keep it stable in a wet state.

However, in recent years, water-disintegratable paper that is stable even in wet conditions has begun to be developed, and for example, toilet seat tissue that uses this paper and can be used to wipe away dirt around the toilet and flush it directly into the flush toilet is now on the market.

The second type of water-disintegratable paper uses polyvinyl alcohol, cellulose derivatives, etc. as a binder for the nonwoven fabric, and uses ethyl alcohol and isopropyl alcohol, which have low solubility in these binders, as an impregnating agent at a concentration of 60% or more.

[Problems to be Solved by the Present Invention] However, water-disintegratable paper containing high concentrations of ethyl alcohol or isopropyl alcohol has the disadvantage that it has poor cleaning performance against water-soluble stains and has a characteristic unpleasant odor when used.

In addition, these products have many disadvantages, such as the need to be careful about the material of the packaging container and film, and also require high airtightness.

Therefore, it has been desired to provide water-disintegratable paper that can maintain a wet state without using such organic solvents.

[Means for Solving the Problems] The present inventor conducted extensive research in order to obtain a water-based wet ice-melting paper. As a result, when polyvinyl alcohol was selected as the binder for the nonwoven fabric and a boron-containing solution was used as the impregnating agent, the conditions required for wet water-disintegrating paper, namely, appropriate moisture, strength, and ice-melting properties, could be met. The present invention was completed by discovering that a water-disintegratable paper that satisfies the above requirements can be obtained.

That is, the present invention provides a wet water-disintegrable paper characterized in that a nonwoven fabric containing polyvinyl alcohol as a binder is impregnated with a boron-containing solution.

Polyvinyl alcohol, which is the binder for the nonwoven fabric used in the present invention, may be in either fibrous or powdered form, and it may not be completely converted into polyvinyl alcohol and may partially contain unsaponified vinyl acetate. It's okay to have one.

In addition, the fibers other than polyvinyl alcohol constituting the nonwoven fabric may be fibers having the property and length to decompose in water when the binder polyvinyl alcohol is dissolved, such as rayon, cellulose, polyamide, polyester, polypropylene, etc. or a mixture thereof.

The content ratio of polyvinyl alcohol in the nonwoven fabric is 5 to 1
00% by weight (hereinafter simply referred to as "%"), preferably 5
~20%. The content ratio of polyvinyl alcohol is 5
If it is less than %, sufficient ice-melting properties cannot be obtained.

On the other hand, boron-containing solutions that are impregnating agents include boric acid,
A boron-containing compound such as borax 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 1 to 8%, and when borax is used, the concentration is preferably 1 to 2%.
It is preferably 0%, particularly 1 to 8%.

This boron-containing solution has a pH of 1 to 7, particularly 3 to 6.0, in order to improve the ice-melting properties of the wet water-dissolving paper of the present invention.
It is desirable to keep it within the range of 5. For this purpose, buffers such as potassium hydrogen citrate-citric acid, potassium hydrogen citrate-sodium hydroxide, trisodium citrate-citric acid, tartaric acid-sodium tartrate, lactic acid-sodium lactate, sodium hydrogen phosphate-citric acid, etc. It is preferable to add a buffering agent to the boron-containing solution.

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

The wet water-disintegratable paper of the present invention is prepared by impregnating a nonwoven fabric containing polyvinyl alcohol as a binder with a boron-containing solution, and adding other optional ingredients as necessary, such as a bactericide, a surfactant, and a fragrance. , a coloring agent, etc. may be blended and impregnated.

Note that, in order to prepare wet water-disintegrable paper with better performance, it is desirable to form the wet water-disintegrable paper into a composite structure.

In other words, as schematically shown in Figure 1, if an inner layer of wet water-disintegratable paper with granular polyvinyl alcohol as a binder is sandwiched between an outer layer of wet water-disintegratable paper with fibrous polyvinyl alcohol as a binder, the inner layer of wet water-disintegrable paper with granular polyvinyl alcohol as a binder is sandwiched from both sides. is more preferable because it increases the amount of water that can be retained and does not reduce ice-melting properties.

[Function] The wet water-disintegrable paper of the present invention is stable in a moderately moist state, but is extremely easily disintegrated in a large amount of water.

This is presumed to be due to the following effects. In other words, when the nonwoven fabric is used in a state where it contains an appropriate amount of water, boric acid etc. and the hydroxyl groups of polyvinyl alcohol pseudo-bond and form a gel, making the polyvinyl alcohol insolubilized.
Nonwoven fabrics do not dissolve in water.

However, when the nonwoven fabric is placed in a large amount of water (dumped), the insolubilization state is broken by the action of the large amount of water, and the polyvinyl alcohol is dissolved, and the nonwoven fabric is also considered to be hydrolyzed. .

[Effects of the present invention] The wet water-disintegrable paper obtained as described above has sufficient moisture to remove dirt, etc., and is very easily disintegrated by discarding it in water, so it can be used in toilets. It can be used for wiping, cleaning, etc., and as a volatilization paper for liquid fragrances.

The wet water-disintegratable paper of the present invention does not have an unpleasant odor unlike conventional paper, and can be easily packaged, making it extremely practical.

[Example] Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Rayon paper (5cm x 5c+++) containing 10% polyvinyl alcohol fibers was impregnated with twice the weight of boric acid aqueous solutions of various concentrations and pH. , 0) was investigated.

Ice melting ability is determined by adding 5 liters of water to a 1 liter cylinder with an inner diameter of 65 mm.
00ml, and place 1 5cm x 5cm test piece in it.
Insert the cylinder and rotate it 180 degrees around the axis of the cylinder. This operation was performed as one ice-thawing operation, and the number of ice-thawing operations required for the test piece to be melted was observed.

The results are shown in Table 1.

(Margin below) 10- No. table 1.0 3.0 4.0 5.0 O: Ice melting operation 5 [Ice melt within ij1.

△: Ice melts within 5 to 15 times of water M operation.

×: No melting after 15 ice melting operations.

-10- Example 2 Various concentrations and amounts of boric acid water were applied to a nonwoven fabric containing polyvinyl alcohol (45% rayon with a fiber length of 3 mm; 10% polyvinyl alcohol with a fiber length of 3 mm; 45% bulb) measuring 5 cm in length and width. After being impregnated and left at 40°C for 48 hours, the tensile load and water disintegration were examined.

The ice-melting property was measured in the same manner as in Example 1, but the results were shown as the number of ice-melting operations (the number of ice-melting operations in which the non-woven fabric was divided into two) and the number of ice-melting operations (the number of ice-melting operations in which the non-woven fabric was completely melted). .

The results are shown in Table 2.

(The following is a blank space) 11- Table Example 3゜The same rayon paper used in Example 1 was impregnated with a boron-containing solution containing 4% boric acid to an amount twice the weight of the rayon paper. The change in tensile strength was investigated.

The results are shown in Figure 2, and it is clear from the results that at a pH of about 3 to 7, the ice-melting properties are maintained while wiping the surfaces of plastics, floors, ceramics, etc. Wet strength, which is said to be
It showed strength combined with wet abrasion resistance.

121 Example 4゜A valve layer was provided between two sheets of rayon paper in the same manner as used in Example 1, and the whole was embossed using powdered polyvinyl alcohol as a binder to produce a composite water-disintegratable paper. This composite water-disintegrable paper was impregnated with various amounts of boric acid water to obtain wet water-disintegratable paper, and after being left at 40°C for 48 hours, the tensile load and water-disintegrability were examined.

The results are shown in Table 3. The amount of boric acid water impregnated into the composite ice-breaking paper was 1.5 times by weight, and the pI (pI) of the boric acid water after impregnation was adjusted to 4.

Table 3 0280 B105 0.355 0. +00 0.680 0.140 3- Example 5゜The same composite water-disintegratable paper used in Example 4 was impregnated with various concentrations of borax water, and after being left at 40°C for 48 hours, the tensile load and The water degradability was investigated. The amount of boric acid water impregnated into the composite water-disintegrated paper was 1.5 times by weight, and the pH of the boric acid water was adjusted to 2 to 4.

Table 4 6.0 2.5 4 28
0.415115

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing schematically showing the wet water-disintegratable paper of the present invention having a laminated structure. FIG. 2 is a diagram showing the relationship between the pH of wet water-disintegrated paper and the crushing strength. Above 14-

Claims (5)

[Claims] (1) A wet water-disintegrable paper characterized by impregnating a nonwoven fabric containing polyvinyl alcohol as a binder with a boron-containing solution. (2) The wet water-disintegratable paper according to claim 1, wherein the boron-containing solution is a solution containing boric acid or borax. (3) The wet water-disintegratable paper according to claim 1, wherein the boron-containing solution has a pH of 1 to 7 when impregnated into the nonwoven fabric. (4) Polyvinyl alcohol content in the nonwoven fabric is 5 to 1
The wet water-disintegratable paper according to claim 1, wherein the wet water-disintegratable paper has a content of 0.00% by weight. (5) The wet water-disintegratable paper according to claim 1, which is impregnated with a boron-containing solution 0.5 to 10 times the weight of the nonwoven fabric.