JPS6350600A - Water-dispersible paper - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention has a water-disintegrable property that has sufficient strength even in a wet state during use, and that disintegrates when disposed of in a large amount of water, such as in a flush toilet. Regarding paper.

[Conventional technology and its problems] Conventional baby wipes, wet wipes for women's sanitary use, and wet wipes for defecation treatment use nonwoven fabrics made by spunbond method and water-insoluble binders as tissue base materials. The non-woven fabric obtained by completely binding the fibers is used, and for example, if it is disposed of in a flush toilet, the product retains its original form, so it does not cause blockages in sewage pipes. The function of the simple septic tank could be inhibited.

Therefore, a method was proposed in which a nonwoven fabric using a water-soluble binder is impregnated with an aqueous solution containing specific salts that temporarily make the water-soluble binder insoluble in water, or salts at a predetermined concentration or higher necessary for salting out. - Polyvinyl alcohol as a water-soluble binder; - A boric acid aqueous solution with a concentration of 3% or more as an aqueous solution containing specific salts that temporarily make it water-insoluble; and a solution for salting out polyvinyl alcohol. An aqueous sodium sulfate solution with a concentration of 7% or more is used as a solvent.

However, the above-mentioned aqueous sulfuric acid solutions and aqueous sodium borate solutions have safety problems such as primary irritation to the skin, irritation to the eye mucous membranes, and oral toxicity.

Furthermore, JP-A-59-144428 discloses an ice-melting nonwoven fabric impregnated with an oil-based liquid, but the ice-melting nonwoven fabric is made of a nonwoven fabric made of cellulose fibers or a water-soluble binder. A nonwoven fabric with fibers bonded together is used, and the nonwoven fabric is impregnated with an oil-based liquid, so in a wet state, there is no destruction of hydrogen bonds between cellulose fibers or destruction of the water-soluble binder, and its strength in use is sufficient. It also decomposes when immersed in large amounts of water.

However, when cleaning the skin of a human body, the impregnated oily liquid may adhere to the skin and cause stickiness or discomfort, and since human body excrement is water-soluble, the impregnated oily liquid may adhere to the skin and cause a sticky or uncomfortable feeling. There are problems such as difficulty in mixing with liquids.

Furthermore, when the skin of a human body is wiped with ice-dissolving nonwoven fabric moistened with water, fibers (hereinafter referred to as paper dust) generally come off and may adhere to the skin. As an example, this fact is confirmed when currently commercially available toilet paper is used after being moistened with water.

The generation of paper dust becomes a particularly serious problem when ice-melting nonwoven fabrics such as those mentioned above are used for wipes.
Furthermore, if measures are taken to prevent the generation of paper dust, there are problems such as a decrease in the ice-melting properties of the nonwoven fabric, and so far no technical problem has been solved.

The present invention was made in order to solve the above-mentioned problems.It has sufficient strength in a wet state, and when disposed of in a flush toilet, its shape is easily destroyed and it becomes fibrous or small block. To provide a scale with water-disintegrable paper that is dispersed in a uniform manner and does not generate paper dust during use.

[Means for Solving the Problems] That is, the present invention provides a fiber layer in which fibers are partially bonded with a water-insoluble resin on one or both sides of a fiber layer in which the fibers are not bonded with a water-insoluble resin. The present invention relates to a water-disintegrable paper formed by pasting together and a water-disintegrable paper formed by partially cutting the water-disintegrable paper.

In this specification, ice-melting means that paper can easily cause blockages in sewage pipes when disposed of in flush toilets, etc.
It refers to the property of being broken by running water to a size that does not impede the function of a simple septic tank.

[Function] The water-disintegrable paper of the present invention has a fiber layer in which fibers are partially bonded with a water-insoluble resin on one or both sides of a fiber layer in which the fibers are not bonded with a water-insoluble resin. So,
The fiber layer provided with the water-insoluble resin prevents the fibers from detaching even in a wet state.

If this paper is disposed of, for example in a flush toilet, the fibrous layer in which the fibers are not bonded with water-insoluble resin will easily disperse into fibers, leaving a thin fibrous layer with water-insoluble resin. .

Even in the case of water-disintegrable paper with a three-layer structure, the middle layer is divided into two from the unbonded fiber layer by a water-insoluble resin,
The above phenomenon occurs. However, because this remaining fiber layer is thin and the fibers are partially bonded with water-insoluble resin, mechanical forces such as water flow in sewage pipes or water flow in simple septic tanks can cause small blocks. destroyed. Therefore, there will be no blockage of sewage pipes and no interference with the function of the simple septic tank. Furthermore, in order to improve the ice-dissolving properties, it is preferable to make partial cuts in the water-disintegratable paper in advance.

In order to create a fiber layer that does not generate paper dust and can be destroyed by weak mechanical forces such as water flow, it is necessary to thin the fiber layer in which the fibers are partially bonded with a water-insoluble resin. Furthermore, it is necessary to provide the water-insoluble resin in spots. If too much water-insoluble resin is used, a continuous resin film will form and will not be destroyed by weak mechanical forces.

[Example] The water-disintegrable paper of the present invention can be produced by providing a thin fiber layer in which fibers are partially bonded with a water-insoluble resin on one or both sides of a fiber layer in which the fibers are not bonded with a water-insoluble resin. , or even by making partial cuts in the bonding paper.

The water-disintegrable paper of the present invention has fibers partially bonded with a water-insoluble resin on one or both sides of the fiber layer where the fibers are not bonded with a water-insoluble resin through a wet lamination process normally carried out in the paper manufacturing industry. It is manufactured by laminating fiber layers.

The fibers used are not particularly limited as to the fiber layer provided with or without water-insoluble resin. For example, in addition to softwood fibers such as red pine and fir, and hardwood fibers such as beech and Quercus oak, there are
Natural fibers for paper making such as woody bast fibers such as gambi, herbaceous bast fibers such as flax, hemp, jute, ramie, leaf fibers such as Manila hemp, sisal hemp, monocot fibers such as bamboo, straw, bagasse, etc. Pulp; regenerated cellulose fibers such as viscose rayon and cupra; polyamide fibers such as nylon; polyester fibers; vinyl chloride fibers; vinylidene chloride fibers; polypropylene fibers; acrylic fibers; polyvinyl alcohol fibers, etc. . Among these, fiber pulp for paper making and rayon fibers such as rayon are preferred because they are easily decomposed by microorganisms such as Cellulomonas and Cervibrio bacteria.

When synthetic fibers are used, they are not used alone in wet lamination processing with a fiber layer provided with a water-insoluble resin, which will be described later, but are used in a mixture with natural fiber pulp for papermaking. The amount of synthetic fiber used is preferably 50% by weight or less. If the amount used exceeds 50% by weight, it becomes difficult for the fiber layers to adhere to each other, making wet lamination processing difficult.

Furthermore, the length of these fibers is not particularly limited.

Examples of fibers used in the fiber layer provided with a water-insoluble resin include natural fibers for paper manufacturing such as the above-mentioned softwood fibers, hardwood fibers, woody bast fibers, herbaceous bast fibers, leaf U & fibers, and monocot fibers. Preferably it is pulp. In order to prevent paper powder from falling off, it is preferable that the fibers are mechanically entangled with each other, and synthetic fibers generally do not have this mechanical entanglement between the fibers, making it very easy for the fibers to fall off. Furthermore, it is preferable to subject this natural fiber pulp for papermaking to the commonly used beating treatment, as the fibers become fibrillated and the mechanical entanglement between the fibers and the soil becomes stronger than when the beating treatment is not performed.

In addition, the fiber length of this natural fiber pulp for papermaking is 1 to 10% from the viewpoint of paper dust generation and ice meltability when disposed of in a flush toilet.
It is preferably about m+s, and particularly preferably about 3 to 7111!1 in order to break the fiber layer provided with this water-insoluble resin to an appropriate size.

If water-disintegratable paper is produced using fibers with a fiber length greater than 10 mm, the ice-dissolving properties will be reduced, and if the fiber length is less than 1 mm, paper dust will be generated, which is not preferable. An example of such a fiber is softwood bleached kraft pulp (hereinafter referred to as NBKP).

The water-insoluble resin used to partially bond the fibers must be applied in fine spots. If the water-insoluble resin is continuously applied, the fibrous layer will not be broken by weak mechanical forces such as water flow. Therefore, the water-insoluble resin must be fine and capable of being used in wet papermaking. Such resins include short fiber long thermoplastic fibers for wet papermaking, and specific examples of such fibers include Daiwabo Polypro [F] (Daiwabo ■) and Chisso ES (Chisso ■).
, polyethylene synthetic pulp SvP [F] (Mitsui Petrochemical Industries), Haltex [F] (Lefster ■), and the like. Among these, polyethylene synthetic pulp SwP■ and polypropylene synthetic pulp Partex■ are particularly suitable because they have shorter fiber lengths and are multibranched compared to other thermoplastic fibers.

The amount of these polyolefin synthetic pulps adhered varies depending on whether or not partial cuts are provided, as will be described later. The amount of adhesion is usually 0.4 to 1.7 g1rd, but if no partial cuts are made, the amount is 0.4 to 1.7 g1rd.
It is preferably within the range of 0 g/rd, and in the case where partial cuts are provided, it is preferably within the range of 0.4 to 1.4 g/rr'. The amount of adhesion is 0.4g1r
If it is less than d, a large amount of paper dust will be generated, and if the amount used is more than the above-mentioned upper limit, the ice-melting property will deteriorate, which is not preferable.

Next, the basis weight of the fiber layer to which the fibers are partially bonded with this water-insoluble resin is preferably within the range of 4 to 40 g/I. From the point of view of the present invention, it is preferable that this fiber layer be as thin as possible, but in actual papermaking, 4g1rd
If it is less than 40g, there may be areas where the fibers do not accumulate or
If it exceeds /rrr, it is not preferable because the ice-melting properties will be reduced.

The fiber layer in which the fibers are not bonded with a water-insoluble resin preferably has a certain thickness in order to maintain the strength of the product, and preferably has a basis weight of about 50 to 150 g/m2.

Wet lamination processing is carried out by the conventional method as described above. In other words, 2 or 3 sheets are produced in the paper making process.
The base paper is obtained by stacking sheets of wet paper, dehydrating them under pressure, and drying them.

In the method of bonding fibers with a thermoplastic resin, the obtained base paper can be subjected to surface treatment using a roll, hot air, or infrared heating method at a temperature equal to or higher than the melting point of the thermoplastic resin.

The partial cuts in the partially cut water-disintegrable paper of the present invention include discontinuous dotted cuts where the entire cross section of the product is cut, so-called perforation-like cuts, and water-insoluble resin cuts. It may be a so-called half-cut cut in which the cut is made only in the applied fiber layer. Therefore, if a fiber layer provided with a water-insoluble resin is provided on both surfaces of a fiber layer not provided with a water-insoluble resin, similar cuts may be provided on both surfaces.

The method of making these partial cuts is determined by the strength and ice-melting properties of the product. That is, if a large number of partial cuts are provided, the strength of the water-disintegrable paper will inevitably decrease. Therefore, there is a limit to the number of cuts. If the strength of the product decreases too much, the strength of the fiber layer not provided with the water-insoluble resin may be increased. Examples of methods for increasing the strength of the fiber layer include increasing the basis weight, increasing the length of the fibers used, improving the entanglement of the fibers (beating), and using self-adhesive rayon (for example, Rayon 5BII). [F] (Method using the Daiwabo side) etc.

It is preferable to make the partial cuts as evenly as possible from the ice-dissolving side of the water-disintegratable paper. As an example, the first example is the case where perforation-like cuts are provided.
As shown in the figure. Of course, this cut is not limited to such a shape.

Next, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples, and may be modified as appropriate within the scope of the present invention.

Example I Using TAPPI standard square sheet machine,
Softwood bleached kraft pulp with a beating degree of 30°SR (hereinafter referred to as
A mixed paper stock containing 8 parts by weight of NBKP (referred to as 30°SR) and 0.6 parts by weight of polyethylene synthetic pulp SWP[F]E-400 (manufactured by Mitsui Petrochemical Industries, Ltd.) was made into paper by a conventional method, and the dry weight was 8 parts by weight. .8 g/m2 wet paper (A) was produced.

In addition, a wet paper (B) having a dry weight of 70 g/n was similarly prepared using bleached softwood kraft pulp (hereinafter referred to as NBKP (1' ree)) which had not been subjected to beating treatment.

This wet paper (A) and wet paper (B) are stacked together, and after dehydration under pressure,
This was dried to produce a base paper with a two-layer structure. Heat this base paper to 150℃
Heat treatment was performed using a heated roller to obtain water-disintegrable paper.

The physical properties of the obtained water-disintegratable paper include wet tensile strength, breaking length,
The state of paper dust generation and ice melting properties were investigated using the following methods. The results are shown in Table 1.

(Wet tensile strength) The resulting water-disintegrable paper has a width of 15m+++ and a length of 100m+.
After cutting (7) into strips of S, gently immerse it in distilled water for 10 seconds, take it out, wipe off the water with a filter paper, and place it in a universal compression tensile tester (Shinko Tsushin Kogyo TCM-200).
j, tensile speed 10/min, test piece gripping interval 50II
The test was conducted under the conditions of I11, and the indicated load value at the time of fracture of the test piece was taken as the tensile strength.

Note that the tensile strength when wet is preferably 100 g or more in practical terms.

(rupture length) The tearing length was measured based on JIS P 8113.

(State of paper powder generation and ice-melting properties) Cut the water-disintegratable paper obtained above to LOcm x 20cm, with the surface where the fibers are partially adhered with water-soluble resin as the top surface, to a size of LOcm x 10cm. After folding it in half as shown, the paper was sprayed with distilled water using a sprayer so that the amount of impregnation was 200% of the dry weight of the nonwoven fabric to make a wet tissue, and the state of paper dust generation and ice melting properties were examined. Ta. The state of paper dust generation is approximately 70% on a transparent glass plate.
Wet tissue 10 times at a pressure of g/cm2
was rubbed to see if the fibers were detached. The state of paper dust generation was determined based on the following criteria.

A: No fiber detachment was observed on the glass plate.

B: Detachment of 2 to 3 fibers is observed on the glass plate.

C. Detachment of 5 to 10 fibers is observed on the glass plate.

D = Detachment of 10 to 20 fibers from the glass plate was observed.

A large number of fibers were observed to be detached from the glass plate.

In terms of practical paper dust generation criteria, A to C were considered suitable, while paper dust and E were judged to be unsuitable due to conspicuous paper dust.

In addition, in the ice melting test, the capacity was 40Ω as shown in Figure 2.
30 g of water (2) and one test sample (3) were placed in an experimental aeration tank (1), and three aeration ports (φ3 mm holes) were provided at the tip of a rubber tube with an inner diameter of 10 mm. After installing the steel pipe on the bottom of the experimental aeration tank (1) as shown in Figure 2, air (flow rate: 5.0β/
The ice was aerated and aerated, and the time required for the size of the pieces after the ice melted to become approximately 30 m+s x 30 mm or less was measured.

The standard size of debris after ice melting is 30m+s x 3
The reason why we set it to 0m1m or less is because of the size of this size,
This was done in consideration of not interfering with the function of the simple septic tank, and the size of the debris reached 3011I within 180 minutes!
If it is 1×3011111 or less, this function will not be inhibited, so this case is suitable.

Comparative Example 1 Polyethylene synthetic pulp SνP E-400 in Example 1
Paper was produced in the same manner as in Example 1, except that no paper was used, and its wet tensile strength, tearing length, paper powder generation state, and ice-melting properties were examined. The results are shown in Table 1.

Comparative Example 2 Commercially available toilet vapor (tsubo 120g/g)
．． 6 g was taken and folded into 4 sheets, and the wet tensile strength, tearing length, paper dust generation state, and ice melting property were examined in the same manner as in Example 1. These results are shown in Table 1.

Comparative Example 3 We took 1.8 g of commercially available tissue paper (115 g/m2), folded it into 5 sheets, and measured the wet tensile strength, tearing length, paper powder generation state, and ice melting property in the same manner as in Example 1. Examined. These results are shown in Table 1.

[Margins below] The papers of Comparative Examples 1 and 2 generated too much paper dust to be practical, whereas the water-disintegrable paper of Example 1 hardly generated any paper dust and had a sufficient amount of paper dust. It was practical. In terms of ice-melting properties, Example 1 was longer than 00 minutes because the fiber layer without polyethylene synthetic pulp was first dispersed in the form of fibers, and the remaining fiber layer with polyethylene synthetic pulp was dispersed by water flow. This is because it is gradually broken by a weak mechanical force.

Therefore, in the case of the water-disintegrable paper of Example 1, the time required for the fibrous layer not provided with polyethylene synthetic pulp to disperse into fibers and the thin fibrous layer provided with polyethylene synthetic pulp remaining is the same as that of Comparative Example 1. As in the above case, it takes only about 10 minutes, which is extremely short and does not cause blockage of sewage pipes. In addition, the thin fiber layer covered with polyethylene synthetic pulp is broken into small blocks of 30 mm x 30 mm or less in size in about 100 minutes due to weak mechanical forces such as water flow in the septic tank, which impedes the function of the simple septic tank. There's nothing to do.

The usefulness of the water-disintegratable paper of the present invention becomes even clearer, especially when compared with the physical properties of the tissue paper of Comparative Example 3.

Examples 2 to 13 and Comparative Examples 4 to 1θ A paper stock having the composition shown in Table 2 was prepared, and a fiber layer in which fibers were partially bonded with a water-insoluble resin (
A paper was produced by superimposing wet paper paper A) and a fiber layer in which the fibers were not glued with a water-insoluble resin (wet paper paper B), and its physical properties were investigated in the same manner as in Example 1. The results are shown in Table 2.

[Margin below] As can be seen from the above results, the amount of polyethylene synthetic pulp to be used is 0.000000000000000 in consideration of paper dust generation and ice melting properties.
A range of 4 to 0.8 g/rr11' is suitable. When the amount of polyethylene synthetic pulp used is less than 0.4 r/m2, for example, the physical properties of the paper obtained in Comparative Examples 4, 6, 8, 1 and 12, in which the usage amount is 0.2 g/m2, It can be seen that this method generates a lot of paper dust and is not practical.

Moreover, if the usage amount exceeds 0.8 g/rri'', for example, as is clear from the physical property values of the paper obtained in Comparative Examples 5.7.9.11 and I3, the ice-melting test results in 30 mm
It takes more than 300 minutes for the ice to collapse to a size of 30 mm or less, and its melting properties are extremely poor.
It may impede the function of simple septic tanks. of course,
The ice-melting test adopted was a method conducted based on the Environmental Regulations Notification No. 6 (issued by the Ministry of Health and Welfare) on the 14th of IJ, 1981, and was a test of ice-melting properties under very weak agitation. Under stronger agitation than this condition, even if the usage rate of polyethylene synthetic pulp exceeds 0.8 g/rd, it may easily hydrolyze into fragments of 30 mm x 30+ nm or less.

For example, in Example 1, polyethylene synthetic pulp SWP■E
Paper (10cm x 20cm) made using -400 at 2.0g/g/g without changing the use of other fibers.
When added to a 1 g cylinder along with 500 ml of water, the mouth of the cylinder is covered with plastic wrap, and shaken vigorously up and down several times, it easily dissolves into pieces of 30 mm x 30 mm or less. However, in reality, such strong forces do not occur in sewage pipes or simple septic tanks, so the standard for the ice melting test is that ice should be broken into a size of 30 mm x 30 mm or less within 180 minutes using this test method. is considered appropriate.

Next, the basis weight of the fiber layer provided with water-insoluble resin, that is, thermoplastic polyethylene synthetic pulp, is 5 to 40g1rd.
A range of is appropriate. In other words, as mentioned above, in the present invention, it is preferable that the basis weight of the fiber layer is small;
In practical terms, if the basis weight is less than 5g/I, I
This is not preferable since there may be a portion where nlff1 is not deposited. Furthermore, when the basis weight exceeds 40[/m2], water disintegration becomes poor as seen in Comparative Examples 14, 15 and 16. Although the paper of Comparative Example 14 had excellent ice-melting properties, it produced somewhat more paper dust. This is Nl3KP
This is because the amount of polyethylene synthetic pulp used is small compared to the amount used of (30°SR). These facts are particularly important in the present invention, which is different from conventional wet laminated paper using polyethylene synthetic pulp.

For example, Japanese Unexamined Patent Publication No. 48-fi4204, Utility Model Publication No. 53
Publication No. 46323 discloses two-layer or three-layer wet laminated paper using polyethylene synthetic pulp, and all of the materials disclosed in these publications satisfy the ice-melting properties required in the present invention. Even if the material is produced by reducing the amount of polyethylene synthetic pulp used, as mentioned above, the basis weight in particular will have a large effect, and it will differ from what is disclosed in these publications. I understand.

Example 14 NBKP (30' SR) 8 in the same manner as Example 1
Weight parts and polyethylene synthetic pulp SWP E-4000
, 6 parts by weight of mixed stock was made into paper, and the dry weight was 8.6 g/
Two sheets of wet paper (A) and wet paper (C) were prepared. Further, a wet paper (8) having a dry weight of 70 g/g was produced in the same manner as above using only NBKP (rrce).

Next, the wet papers (A), (B), and (C) were stacked one on top of the other in order from "-", and were dried after being pressed to produce a base paper with a three-layer structure. This base paper was heat-treated with a heated roller at 150°C to produce water-disintegrable paper.

Table 3 shows the physical properties of this water-disintegratable paper.

Table 3 The water-disintegrable paper obtained in Example 14 has a somewhat slower ice-melting property than the water-disintegrable paper obtained in Example 1. This is because in the case of the water-disintegrable paper of Example 14, the sample is divided into two parts from the middle layer, that is, the wet paper (B), which requires time.

Example ■5 In the same manner as in Example 1, 8 parts by weight of NBKP (30°SR) and polyethylene synthetic pulp swP■E-4001,
A wet paper (A) having a dry weight of 9 g/g was produced by making paper from 0 parts by weight of the mixed paper stock. Also NBXP (f' ree)
A wet paper paper (B) having a dry weight of 70 g/m 2 was similarly produced using the following. Next, the wet paper paper (A) and the wet paper paper (B) were overlapped, pressed, and dried to produce a base paper with a two-layer structure.

This base paper was heat treated with a heated roller at 150°C, and then partially cut to produce water-disintegratable paper.

Note that perforations shown in FIG. 1 were provided as partial cuts. Table 3 shows the physical properties of this water-disintegratable paper.

A test piece for measuring wet tensile strength was prepared by cutting it into a size of 15 mm x loo+o+s as shown in FIG. For comparison, the results of measurements using the non-perforated paper of Comparative Example 7 are also listed in Table 3.

Example 16 In Example 13, the wet paper (B) was NBKP (f're
e) A water-disintegrable paper was prepared in the same manner as in Example 13, except that 7 parts by weight and 3 parts by weight of hollow flat rayon SBH■ (1.5 denier x 7 mm (Daiwa Boseki ■) with a dry weight of 70 g/rr? were used. Paper was made.

The results are also listed in Table 4.

As can be seen from the results in Table 4 and 2 below, by making partial cuts in advance, the amount of polyethylene synthetic pulp used can be increased, eliminating the generation of paper dust.
In addition, water-disintegratable paper can be used that satisfies ice-dissolving properties. Moreover, as can be seen from the results of Example 14, the structure of the fiber layer not provided with a water-insoluble resin can be sufficiently improved by using fibers that produce a wet tensile strength, in this case hollow flattened fibers. It can be seen that it can be applied to ice-melting wet tissues that have a strength that can withstand practical use.

Examples 17 to 19 and Comparative Examples 17 and 18 A fiber layer (wet paper (A)) in which the fibers were partially bonded with a water-insoluble resin using the paper stock having the composition shown in Table 5 in the same manner as in Example 15.
Paper was made by overlapping a fiber layer (wet paper (B)) in which the fibers were not bonded with a water-soluble resin, and further paper was made by making partial cuts, and its physical properties were measured. The results are shown in Table 5.

[Margin below] From the above results, it can be seen that when partial cuts are made, the appropriate amount of polyethylene synthetic pulp to be used is in the range of 0.4 to 1.2 g/1rd.

Example 20 NBKP (30' SR) 8 in the same manner as Example 1
Part by weight and polyethylene synthetic pulp S P E-4001
, 0 parts by weight of the mixed paper stock was made into paper, and wet papers (A) and (C) having a dry weight of 9 g/g were produced. Also, NBKP (1
' ree) with a dry weight of 70g
A wet paper (B) was prepared. Next, wet paper (A), (B)
and (C) stacked one on top of the other in order from the top, dried after applying pressure, 3
A base paper with a layered structure was prepared. This base paper was heat-treated with a heated roller at 150°C and further cut partially to produce water-disintegrable paper.

Note that the partial cuts were made in the same manner as in Example 15.

Table 6 shows the physical properties of this water-disintegrable paper.

[Margin below] Table 6 Example 21 Polyethylene synthetic pulp SWP■E- used in Example 1
Polypropylene synthetic pulp Paltex [F] (Lefster) was used instead of 400; the others were as in Example 1.
Paper was prepared in the same manner as above, and its wet tensile strength, tearing length, paper powder generation state, and ice meltability were examined. In addition, the original paper is 180
Heat treatment was performed using a heated roller at ℃.

The results are shown in Table 7.

Table 7 Example 22 The water-disintegrable paper obtained in Example 1 was made into a loam x 20 cm
Cut it into pieces, fold it in half to a size of 10 cm
A wet tissue was prepared by impregnating the tissue at a ratio of 0.00%.

The flowability test of this wet tissue was carried out using the flush toilet equipment shown in FIG. 4 under the following measuring method and conditions.

(Measurement method) A toilet bowl (JIS A 5207: C31B) (7) and a low tank (5) installed above the 500 mm of the toilet bowl (7) with a cock (II) at the upper end made of polyvinyl chloride with an inner diameter of 32 mm. A transparent polyvinyl chloride vibrator (8) with an inner diameter of 75 mm is attached below the toilet bowl (7).
) and a transparent vinyl chloride vibrator (9) with an inner diameter of 100 mm from the gradient device/100 to connect it to the septic tank 00).

Next, put the sample (5 wet tissues) into the toilet bowl (7'), open the cock (11), and then
) and observe the flowability of the sample in the vibrators (8) and (9).

(Measurement condition) Flow rate: IOg/1 time Number of sheets tested: 5 sheets/1 time Number of tests: 50 times The results are shown in Table 8.

For reference, commercially available toilet paper (Tsubo Elk)
: 20g/1n2) in the same manner as in Example 22. The results are also listed in Table 8.

Table 8 Table 9 [Effects of the Invention] The ice-melting nonwoven fabric of the present invention has sufficient strength even in a wet state during use, but it dissolves when immersed in a large amount of water, so it does not cause blockages in sewer pipes. It does not cause any pollution or impede the function of the simple septic tank.

In addition, the ice-melting nonwoven fabric of the present invention is made of a material that is safe for the human body, and does not generate paper dust when wet, so it can be used as a wet tissue, a dry tissue, or a hand towel.
Cleaning cloths, etc.: Pants, diapers, etc. used in hospitals, etc.; By adding sterilization and disinfectants, it can be applied to various products such as surgical and food gloves, hats, etc. play.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the shape of the cuts provided in the ice-melting nonwoven fabric of the present invention, Fig. 2 is an explanatory diagram of the ice-melting test method of the test piece used in the examples of the present invention, and Fig. 3 is the book of the present invention. FIG. 4 is a plan view showing the shape of the test piece used in the embodiment of the invention, and FIG. 4 is a drawing of the flush toilet equipment used in the wet tissue circulation test used in embodiment 22. (Drawing codes) (1): Experimental aeration tank (2); Water (3); Test sample (4): Rubber pipe (5) Two-row tank (6): Polyvinyl chloride pipe (7): Toilet bowl (8), (9): Transparent PVC vibe QOI
, septic tank 01): Cook patent applicant Earth Pharmaceutical Co., Ltd. A'7 Figure 4

Claims (1)

[Claims] 1. A water-disintegrable paper obtained by laminating a fiber layer in which fibers are partially bonded with a water-insoluble resin on one or both sides of a fiber layer in which the fibers are not bonded with a water-insoluble resin. . 2. The water-disintegrable paper according to claim 1, wherein the water-insoluble resin is a thermoplastic synthetic pulp, and the amount of the resin adhered is 0.4 to 1.7 g/m^2. 3. The water-disintegrable paper according to claim 1, wherein the paper is formed by laminating a fiber layer in which the fibers are partially bonded with a water-insoluble resin, and the paper is partially cut. 4. The water-disintegrable paper according to claim 1, wherein the water-insoluble resin is a thermoplastic polyolefin synthetic pulp. 5 The fiber layer in which the fibers are partially bonded with a water-insoluble resin is made of paper pulp, and the basis weight of the fiber layer is 4 to 40 g.
/m^2. The water-disintegratable paper according to claim 1 or 3, wherein