JP2931130B2 - Multilayered hydrolyzed paper and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer water disintegrating paper having high strength when impregnated with a chemical such as alcohol and having excellent water dissolving properties.

[0002]

2. Description of the Related Art It is well known that wiping paper is used by impregnating it with cleaning alcohol or the like, and when it is discarded in water, constituent fibers are rapidly dispersed in water. For example, Japanese Patent Publication No. 42-2925 discloses a method for continuously producing a rapidly dissolving detergent-containing cleaning paper, a decorative paper, etc. by etherifying a continuous paper substantially made of fibrous material in the form of paper. I have. According to this technique, papermaking paper on the market can be rapidly dissolved as appropriate. JP-A-1-168999 discloses a technique of mixing water-dispersible papermaking fibers and water-insoluble carboxymethylated pulp to obtain a water-disintegrated paper which is easily dispersible in water and has high strength when impregnated with a chemical solution. doing.

[0003]

According to each of the above-mentioned technologies , for example, a hand-wiping or other wiping paper which is impregnated with a detergent, a disinfectant or another chemical solution to be provided by the present invention is used. You can get some paper.

However, the technology disclosed in Japanese Patent Publication No. 42925/1972 requires a foldable continuous paper, and furthermore, it is necessary to unwind the roll of the continuous paper and carry out the etherification treatment. This is a paper with a large basis weight. In other words, there is a problem that it is difficult to produce a hydrolyzed paper having a relatively small basis weight, for example, about 10 to 50 g / m ² . The technique disclosed in Japanese Patent Application Laid-Open No. 1-168999 is to make a paper stock mixed with a large amount of a water-insoluble carboxymethylated pulp as a paper strength enhancer. When a contact type dryer is used in the dry part of the papermaking process, the contact surface of the paper material strongly adheres to the dryer as drying proceeds, and peeling becomes difficult. Therefore, this technique has a problem that it is difficult to use a general-purpose contact dryer.

Accordingly, the present invention comprises a hydrolytic paper comprising at least two layers, one of the two outermost layers of the hydrolytic paper containing a relatively large amount of a paper-strengthening agent, and the other outermost layer comprising The above problem is intended to be solved by including a relatively small amount of a paper strength enhancer.

[0006]

The gist of the present invention to solve the above problems is as follows.

[0007] The present invention is based on the premise of providing water-decomposable paper and a manufacturing method thereof of a multilayer structure, such water-decomposable paper having a multilayer structure comprising at least two layers, both outermost layers located opposite the water-decomposable paper one comprises the outermost layer is 10 to 60% by weight of paper strength agent, only contains the other outermost layer 5 wt% or less of a paper strength agent of the strength agent is carboxymethyl
Sodium salt of chilled pulp, including said sodium salt
Mixed salt of carboxymethylated pulp, water-soluble polyvinyl
Alcohol, water-soluble polyvinyl alcohol fiber, and
The gist is to be any of these mixtures . Further, in the above-mentioned production method, there is provided a method for producing a multi-layered hydrolyzed paper comprising a step of drying a wet paper using a contact dryer, wherein a paper strength enhancer having a dry weight of 10 to 60% by weight is used. At least a first furnish containing at least 5% by weight of a paper furnish. After obtaining the wet paper as a multilayer structure so that each stock constitutes each outermost layer of the wet paper, the outermost layer of the wet paper comprising the second stock is dried as a contact surface to the contact type dryer. The gist is that the first and second stocks constitute the outermost layer of each of the hydrolyzed papers.

In a preferred embodiment of the production method, the paper strength agent, the carboxymethylated pulp Na
Thorium salt, carboxymethyl containing the sodium salt
Mixed salt of pulp, water-soluble polyvinyl alcohol, water-soluble polyvinyl alcohol fiber, and mixtures thereof
Ru der either.

[0009]

In the hydrolytic paper according to the present invention configured as described above, the outermost layer having a high content of the paper strength enhancer exhibits excellent surface strength even in the state of being impregnated with a chemical solution, and does not easily break. This outermost layer is suitable for use exclusively as a wiping surface. The other outermost layer has a low content of the paper strength agent and contains only at most 5%.
Therefore, this layer disperses promptly in water, and although one outermost layer has a tendency to decrease the water disintegration property of the water disintegrated paper due to the effect of the high strength paper strength agent, it is good for water disintegrated paper. Brings water degradability. Further, in the water-disintegrated paper having such a configuration, the outermost layer having a low content of the paper-strength enhancer in the papermaking process can be used as the contact surface to the contact dryer. This contact surface is extremely easily peeled off from the dryer after drying, so that the productivity of hydrolyzed paper does not decrease even though one outermost layer contains a large amount of a paper strength enhancer.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows a paper making process of the hydrolyzed paper 1 according to the present invention. The process includes at least two series of first and second raw material preparation steps 2 and 2 ′, one short net 9 and one round net paper machine 13, a pickup / felt belt 11, a felt belt 12, a drying cylinder 17 and the like. . In each raw material preparation step 2, 2 ', first and second disintegration tanks 4, 4' for the raw pulp, a sizing agent, a paper strength enhancer, and the like are blended to prepare first and second stocks 10, 10 '. First and second compounding tanks 5, 5 'are provided, which are connected by transfer pipes 6, 6'. The first mixing tank 5 is a head box 7
, The head box 7 faces the belt 9 ′ at one end of the wire part 9 comprising the endless wire mesh belt 9 ′, where the stock 10 is supplied in a fixed amount.
The belt 9 'runs counterclockwise in FIG. 1, and the other end of the wire part 9 contacts the endless pickup / felt belt 11. This belt 11 runs clockwise. On the other hand, the second blending tank 5 ′ is connected to a round paper machine 13, and supplies the stock 10 ′ to the filter tank 12. Round mesh paper machine 13
In FIG. 7, a part of the round net 13 'hangs in the stock 10', and the top of the net 13 'comes into contact with the pickup felt belt 11. The pickup / felt belt 11 picks up the paper layer 14 formed by the first stock 10 from the belt 9 ′ while traveling clockwise, and thereafter,
From 3 ′, the paper layer 15 of the second stock 10 ′ is picked up in a form of being adhered to the paper layer 14. The wet paper web 16 composed of the paper layers 14 and 15 formed on the pickup / felt belt 11 is picked up by the felt belt 12 and then transferred to the surface of a drying cylinder (dryer) 17 to be heated and dried to be subjected to heat drying. It becomes a water disintegrated paper 1 having a structure and is wound up to form a roll 18. Such a series of papermaking steps may use well-known steps and equipment, and additional equipment other than the above may be added as appropriate. In the present invention, in the first raw material preparation step 2, the added amount of the paper strength enhancer is 5% or less based on the dry weight of the stock 10, and in the second preparation step 2 ', the added amount is 10 to 60%. As a result, the wet paper web 16 can be dried by bringing the paper layer 14 having a small amount of the paper strength enhancer into contact with the drying cylinder 17. After drying, the paper layer 14 containing at most 5% of the paper strength agent is easily peeled off from the drying cylinder 17.

FIG. 2 is an enlarged side view of a portion A of the drying cylinder 17 and shows a state in which the paper layer 14 of the wet paper 16 is in contact with the drying cylinder 17. Incidentally, when the paper layer 15 of the wet paper 16 is in contact with the drying cylinder 17, the paper layer 15 strongly adheres to the drying cylinder 17 as the drying proceeds, and the subsequent peeling may be difficult or impossible. .

FIG. 3 is a schematic side view of a water disintegration paper 30 illustrating the mode of use of the water disintegration paper according to the present invention. In the figure, (A) shows two sheets of hydrolyzed paper 1 according to the present invention interposed through a water-decomposable tissue paper 33, a layer 35 containing a large amount of paper strength enhancer becomes the outermost layer, and a layer 34 containing a small amount of paper strength enhancer inside. And integrated by embossing. In this way, the outermost layers of the water disintegrated paper 30 have a high chemical liquid impregnation strength. (B) of the figure is obtained by creping the hydrolyzed paper 30 of (A), and in this case, the hydrolyzed paper 30 that tends to be relatively thick can be given a soft touch.

Next, in a process substantially equivalent to the above-described papermaking process, a multi-layer handmade paper according to the present invention and a single-layer handmade paper as a comparative example were produced, and the results of comparative examination of various properties thereof were obtained. Show. (Example 1) First layer of 30% by weight of sodium salt of carboxymethylated pulp having substitution degree of 0.4 and pH 6 and 70% by weight of bleached softwood kraft pulp, and 5% by weight of sodium salt of the carboxymethylated pulp % And a second layer of bleached kraft pulp of 95% by weight, and a weight ratio of the first layer to the second layer of 1: 1 was used to produce a handmade two-layer paper having a basis weight of 30 g / m ² . Example 2 A first layer of 60% by weight of a mixture of sodium salt and aluminum salt of carboxymethylated pulp having a substitution degree of 0.4 and pH 6 and 40% by weight of softwood bleached kraft pulp and softwood bleached kraft pulp A hand-made two-layer paper having a basis weight of 30 g / m ² was produced with the second layer of 100% by weight. (Example 3) The first layer having 25% by weight of water-soluble polyvinyl alcohol fiber and 75% by weight of softwood bleached kraft pulp was used as one of the outermost layers. % Of the second alcohol layer as an intermediate layer, and
Hand-made multilayer paper was manufactured by sequentially stacking the first to third layers such that the third layer consisting of 95% by weight of bleached kraft pulp and 95% by weight of softwood bleach became the other outermost layer. The weight ratio of each layer was 1: 1: 1 and the total basis weight was 30 g / m ² . (Comparative Example 1) was produced handsheets monolayer sheet of Example 1 of sodium salt of the same carboxymethylated pulp 20 wt and% and a basis weight of 30 g / m ² softwood bleached kraft pulp 80% by weight. Comparative Example 2 The same polyvinyl alcohol as in Example 3 was 20% by weight and softwood bleached kraft pulp was 80% by weight, with a basis weight of 30 g /
It was produced handsheets monolayer sheet of m ^2. Table 1 shows the results of evaluating the surface strength, water disintegration (water dispersibility), and papermaking properties of Examples 1 to 3 and Comparative Examples 1 and 2 when wet by impregnation with a chemical solution. In Table 1, the multilayer papers of Examples 1 to 3 show almost the same performance in terms of surface strength as compared with the single-layer papers of Comparative Examples 4 and 5, and are more excellent in water disintegration (water dispersibility) and papermaking properties. It can be seen that it has excellent performance.

The evaluation method of each evaluation item is as follows. Surface strength (chemical solution impregnation strength) For a test paper impregnated with a 50% propylene glycol aqueous solution twice as much as the test paper weight, a pressing force of 100 g / cm ^2, a speed of 5 cm / sec, and a smooth ABS resin over a distance of about 10 cm Rub the sheet surface by reciprocating motion,
Evaluation was made as follows by the number of reciprocations when the test paper was torn.

A: Breaks 11 times or more B: Breaks 4 to 10 times C: Breaks 3 times or less Water dissolvability (water dispersibility) Put 500 ml of tap water into a 1 liter beaker, and rotate 5 times.
While stirring with a stirrer at 00 rpm, a test paper of 5 × 5 cm was charged, and the dispersion state after 1 minute was evaluated as follows.

A: dispersed in fibrous form B: dispersed papermaking property with small fiber mass Using a small rotary dryer, the outer layer of the test paper having the smaller paper strength agent was brought into contact with the dryer by 100
After drying the wet paper of the test paper at about 60 ° C. for about 60 seconds, the releasability of the test paper from the dryer was evaluated as follows.

A: peels off easily B: peels slightly but slightly adheres C: does not peel

[0019]

[Table 1]

[0020]

With the water-disintegrated paper obtained as described above, it is possible to obtain a wiping paper having a relatively small basis weight and being flexible and easy to handle. Such a wiping paper has a high chemical solution impregnation strength in one outermost layer, while exhibiting excellent water disintegration properties in the other outermost layer, thereby having good water disintegration properties as a whole. Such a water-disintegrated paper can be easily manufactured by bringing the outermost layer having a relatively small paper strength agent into contact with a contact dryer.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a paper making process for producing a hydrolyzed paper.

FIG. 2 is a schematic enlarged view showing a positional relationship between the surface of the contact dryer and water disintegration paper.

FIGS. 3A and 3B are side views exemplifying usage modes of hydrolyzed paper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydrolysis paper 14,15 Outermost layer 16 Wet paper 17 Dryer 10,10 'Stock

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI D21H 27/00 D21H 27/00 E

Claims (3)

(57) [Claims] 1. A water disintegration paper having a multilayer structure comprising at least two layers, wherein the water disintegration paper includes two outermost layers which are opposed to each other.
While the outermost layer of comprises 10 to 60 wt% of a paper strength agent, seen including other outermost layer 5 wt% or less of a paper strength agent, before
The paper-enhancing agent is sodium carboxymethylated pulp.
Salt, carboxymethylated pal containing the sodium salt
Mixed salt, water-soluble polyvinyl alcohol, water-soluble poly
Any of vinyl alcohol fibers and their mixtures
The water-disintegrated paper having the multilayer structure as described above. 2. A method for producing a multi-layer hydrolyzed paper comprising a wet paper web drying step using a contact dryer, comprising: a first stock containing 10 to 60% by weight of a paper strength agent in a dry weight; A second paper stock containing 5% by weight or less of a paper strength agent on a dry weight basis, making the first and second paper stocks each form an outermost layer of the wet paper; By drying the outermost layer of wet paper made of paper stock as a contact surface to the contact type dryer, the first and second stocks constitute the respective outermost layers of the hydrolyzed paper. Water disintegration paper manufacturing method. 3. The paper strength-enhancing agent is a sodium salt of carboxymethylated pulp;
The method for producing hydrolyzed paper according to claim 2, wherein the mixed paper is any one of a mixed salt of methylated pulp, water-soluble polyvinyl alcohol, water-soluble polyvinyl alcohol fiber, and a mixture thereof.