JP2000328491A - Paper for absorbing article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a paper for an absorbing article suitable as a water repelling base paper necessary for constituting the absorbing article by incorporating a multi-valent metal salt in a web containing a carboxylated fiber and/or a fiber containing a binder containing carboxyl group. SOLUTION: This paper for an absorbing article is obtained by incorporating a multi-valent metal salt forming a trivalent metallic ion by dissociating in water, such as AlCl3 to a web consisting of a carboxylated fiber such as a water insoluble carboxymethylated pulp having 0.2-1.5, preferably 0.3-0.7 etherification degree and/or a fiber containing a carboxyl group-containing binder such as a carboxymethylcellulose, etc., by >=1 equivalent, preferably 1.5-3 moles based on the molar amount of the carboxyl group in the above fiber web, and further adding a water repellent processing agent. The absorbing material of the absorbing article composed of a liquid-penetrating surface sheet, liquid-non- penetrating moisture-preventing sheet and liquid-holding absorbing material, is formed by using the above paper for absorbing article as a water-repelling base paper and combining with a water-absorbing main material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an absorbent article paper having excellent wet strength.

[0002]

2. Description of the Related Art Conventionally, absorbent articles such as disposable diapers include, for example, a mount for mounting a pulp fiber web in an absorber, a leak-proof sheet, and various elastic members. Paper is used for carrier sheets and the like. Since such paper requires wet strength, various binders such as a carboxyl group-containing binder are used to increase wet strength.

[0003] However, conventional binders have not yet obtained sufficient wet strength, and there is a demand for absorbent article paper having higher wet strength.

Accordingly, it is an object of the present invention to provide an absorbent article paper having high strength even when wet, and an absorbent article using the absorbent article paper.

[0005]

According to the present invention, a fiber web containing carboxylated fibers and / or a carboxyl group-containing binder contains a polyvalent metal salt which dissociates in water to form a trivalent metal ion. The above object has been achieved by providing an absorbent article paper. In addition, the present invention includes a liquid-permeable top sheet, a liquid-impermeable leak-proof sheet, and a liquid-retentive absorber, and a three-dimensional guard is formed on the left and right side edges of the absorber in the longitudinal direction. 4. The absorbent article according to claim 3, wherein the sheet material is disposed to form a three-dimensional guard, wherein the absorber includes a water-repellent backing sheet and an absorbent body, and the water-repellent backing sheet is an absorbent article according to claim 3. Provided is an absorbent article which is made of an article paper and whose left and right sides in the longitudinal direction cover the left and right sides in the longitudinal direction of the absorbent main body and are located on the left and right side edges on the front side of the absorbent main body. Thereby, the above object has been achieved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described. The absorbent article paper of the present invention comprises a fiber web containing carboxylated fibers and / or a carboxyl group-containing binder, containing a specific polyvalent metal salt.

[0007] The fibrous web preferably comprises pulp as a main component. Examples of the pulp include wood pulp such as coniferous or hardwood chemical pulp (LBKP, NBKP), semi-chemical pulp and mechanical pulp, mercerized pulp and cross-linked pulp obtained by chemically treating these wood pulp, and non-wood based pulp such as hemp and cotton. Fibers and cellulosic fibers such as regenerated fibers such as rayon fibers are preferred. Among these materials, wood pulp, mercerized pulp obtained by chemically treating these wood pulp, crosslinked pulp, and the like are more preferable from the viewpoints of product cost, sheet strength, and papermaking suitability. These materials may be used alone or in combination of two or more in order to appropriately adjust the strength and air permeability of the obtained waterproof paper. Further, in order to control the air permeability and flexibility of the obtained absorbent article paper, the pulp and the synthetic pulp can be used in combination. In this case, the compounding amount of the synthetic pulp is preferably 100 parts by weight or less, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the pulp of the waterproof paper. As the synthetic pulp, fibers made of polyolefin resin such as polyethylene fibers and polypropylene fibers can be used, and fibers made of high-density polyethylene or linear low-density polyethylene are particularly preferably used.

The carboxylated fiber used in the present invention is a fiber obtained by introducing a carboxyl group into a fiber such as pulp, and a water-insoluble fiber can be used. A water-insoluble carboxymethylated pulp having a degree of etherification of 0.3 to 5 is preferred.
A water-insoluble carboxymethylated pulp of 0.7 is more preferred for further improving wet strength. Further, the carboxylated fibers include various salt types such as an acid type, a sodium salt, a calcium salt, an aluminum salt, a barium salt, a zinc salt, a copper salt, and a manganese salt. Among them, a calcium salt or a calcium salt is included. The mixed salt type is preferably used in the present invention.

The carboxyl group-containing binder used in the present invention includes polysaccharide derivatives, synthetic polymers, and natural products. Examples of the polysaccharide derivative include carboxymethyl cellulose, carboxyethyl cellulose, carboxymethylated starch and the like. Of these, carboxymethyl cellulose is particularly preferred. Examples of the synthetic polymer include a polymer of an unsaturated carboxylic acid, a copolymer of two or more unsaturated carboxylic acids, or a copolymer of an unsaturated carboxylic acid and a monomer copolymerizable with the unsaturated carboxylic acid. Polymers. Such unsaturated carboxylic acids include
Acrylic acid, methacrylic acid, itaconic acid, crotonic acid,
Examples include maleic anhydride, maleic acid, fumaric acid, and the like. As monomers copolymerizable with unsaturated carboxylic acids,
Esters of these unsaturated carboxylic acids, olefins such as vinyl acetate and ethylene, acrylamide, vinyl ether and the like can be mentioned. Among them, the unsaturated carboxylic acid is preferably acrylic acid, methacrylic acid, for example, polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymer, acrylic acid or methacrylic acid and alkyl acrylate or alkyl methacrylate And copolymers. As a natural product, alginic acid, xanthan gum, dielan gum, tarragant gum, pectin and the like can be used.

[0010] When the carboxylated fiber is used, pulp and synthetic pulp may not be used. That is, the fiber web can be configured as follows. A fibrous web in which the constituent fibers consist only of carboxylated fibers. A fibrous web in which the constituent fibers consist of a mixture of carboxylated fibers and other fibers (the pulp and the synthetic pulp). The constituent fibers consist only of the carboxylated fibers and further contain carboxyl groups. The fiber web constituting a binder comprises a mixture of a carboxylated fiber and another fiber, and the fiber web comprising a carboxyl group-containing binder further comprises only another fiber, and further comprises a carboxyl group-containing binder. Fiber web

The content of carboxylated fibers in the fibrous web in the above-mentioned configuration is preferably 10 to 100% by weight based on the total weight of the fibrous web.
More preferably, it is 0 to 50% by weight. Further, the content of the carboxyl group-containing binder in the above-mentioned configuration is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the fiber web containing no binder, and 1.0 to 1.0 parts by weight.
More preferably, it is set to 5 parts by weight. By making each of them equal to or more than the above lower limit, the effect of imparting strength can be satisfactorily exhibited, and by making the amount equal to or less than the above upper limit, it is possible to achieve excellent cost and texture.

The fibrous web may further contain a water repellent, and by including the water repellent, water can be imparted to the absorbent article paper of the present invention. As a result, the wet strength can be further improved, and when used as a mount for an absorber, as in the case of an absorbent article described later, the amount of the leak-proof sheet used is reduced and the anti-moisture property is improved. You can also. Here, “water repellency” means a state in which the property of absorbing water is suppressed as compared with untreated paper, and specifically, physical properties enough to satisfy the Krem water absorption height described below. Has the following meaning.
Examples of the water-repellent agent include a sizing agent, a fluorine-based or silicone-based treating agent, and the sizing agent is preferably used from the viewpoint of cost and convenience of the treatment method. The sizing agent is classified into a non-additive sizing agent and a surface sizing agent according to the method of use. In the present invention, a sizing agent generally used can be used. When the sizing agent is classified by raw material, there are a rosin sizing agent, a wax sizing agent, a petroleum resin sizing agent, a synthetic sizing agent, and the like. Natural rosin / maleic anhydride copolymer, hydrogenated rosin / maleic anhydride Copolymer, rosin / maleic anhydride copolymer wax emulsion, petroleum resin / maleic anhydride copolymer, alkyl / ketene / dimer, alkenylsuccinic anhydride, stearic anhydride, etc., but are not limited thereto. Not something. The amount of the sizing agent is preferably 0.05 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the fibrous web containing no sizing agent.
When the content is 0.05 parts by weight or more, a water-repellent treatment effect can be obtained, and when the content is 5 parts by weight or less, it is advantageous in terms of cost.

Further, a sizing agent fixing agent may be blended for fixing the sizing agent. As the sizing agent fixing agent, a sulfuric acid band, sodium aluminate, polyaluminum chloride or the like is used, and it is desirable to add 50 to 400 parts by weight to 100 parts by weight of the sizing agent.

The polyvalent metal salt used in the present invention is a compound which dissociates in water to form a trivalent polyvalent metal ion when dissolved in water. In addition, the polyvalent metal salt may generate a polyvalent metal ion without being dissolved in water. Examples of the polyvalent metal ion include Al ³⁺ and Fe ³⁺ . Examples of the polyvalent metal salt include AlCl ₃ , Al
(OH) ₃ , FeCl _{3 and the} like.
Cl ₃ is preferred from the viewpoints of safety, anti-coloring property and solubility.

The amount of the polyvalent metal salt is based on 1 mole of the carboxyl group contained in the fiber web.
It is preferably at least 1 mole (equimolar), and
More preferably, it is molar. By setting the amount to be equal to or more than the equimolar amount, the effect of developing the strength is sufficiently obtained.

If necessary, additives such as dyes and pigments which are usually used for this type of paper may be added to the absorbent article paper of the present invention as long as the desired effects of the present invention are not impaired. .

The absorbent article paper of the present invention preferably has an air permeability of 2 to 900 sec / (300 ml · 32
Sheets), more preferably 30 to 150 sec / (300 m
1, 32 sheets), and the basis weight is preferably 14 to 60 g /
m ² , more preferably 16 to 25 g / m ² .

The air permeability is 2 sec / (300 ml · 3
When the number is two or more, the transportability is improved in the diaper manufacturing line, and the productivity is improved. 900 sec / (3
(00 ml, 32 sheets) or less, productivity is improved. When the basis weight is 14 g / m ² or more, the strength of the backing sheet is generally sufficient, and breakage hardly occurs during processing or actual use of the product. When the content is 60 g / m ² or less, there is a sufficient merit in terms of cost, and the product does not have a feeling of stiffness.

The air permeability is determined according to JIS-P8141.
Measure according to That is, the absorbent article paper is 70 × 70
mm, 32 sheets are piled up, and an air permeability measuring device [GURLEY DENSOMETER manufactured by Kumagaya Riki Kogyo Co., Ltd.]
(Trade name)], the time required for 300 ml of air to permeate was measured, and this was defined as the air permeability.

When the absorbent article paper has been subjected to the water-repellent treatment with the water-repellent treatment agent, the water absorption height of the Krem is preferably 5 mm / 10 min or less, more preferably 0 mm / 10 min. Krem absorption height 5
When it is set to be not more than mm / 10 min, when applied as a mount or a leak-proof sheet for the absorber, water repellency is obtained to such an extent that bleeding from the absorber can be suppressed even in a state where no body pressure is applied. Here, the Krem water absorption height is measured according to JIS-P8141. That is, the water-repellent backing paper is cut into a strip having a width of 20 mm and a length of 200 mm.
The part up to the mm part was immersed in ion-exchanged water. Ten minutes after immersion in water, the number of millimeters of water sucked up is measured, and this is determined as the Krem water absorption height.

The absorbent article paper of the present invention is produced by a commonly used wet papermaking method, and the carboxyl unit-containing binder and the polyvalent metal ion are mixed at the time of papermaking or coated after papermaking. Can be added.

The absorbent article paper of the present invention can be used, for example, as a backing sheet for mounting a pulp fiber web in an absorbent body, a leak-proof sheet, a carrier sheet for attaching various elastic members, and the like. Hereinafter, application examples of the absorbent article paper of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the disposable diaper 1 as an absorbent article according to the present embodiment includes a liquid-permeable top sheet 2, a liquid-impermeable leak-proof sheet 3, and a liquid-retentive absorber 4. Equipped, absorber 4
A sheet material 61 for forming a three-dimensional guard is arranged on both left and right edges in the longitudinal direction to form a three-dimensional guard 6.
The disposable diaper 1 of the present embodiment is a fastening tape 1 that is fixed to the left and right side edges B1 and B2 of the back part B when used.
This is a so-called deployable disposable diaper in which 1 is arranged. And, at the time of use, the waist portion 8 located around the waist of the wearer and the leg portion 7 located around the legs,
Waist elastic member 81 and leg elastic member 71, respectively
Are arranged to form waist gathers and leg gathers. A three-dimensional guard elastic member 64 is disposed at a free end 63 of the three-dimensional guard 6.

In the disposable diaper 1 of the present embodiment, the absorber 4 includes a water-repellent backing sheet 41 and an absorbent body 42. The water-repellent backing sheet 41 is made of the absorbent article paper of the present invention containing the above-described water-repellent treatment agent, and the left and right side edges 41a in the longitudinal direction cover the left and right side edges in the longitudinal direction of the absorbing body 42a. It is arranged so as to be located on the left and right side edges on the surface side of the surface 42.

More specifically, the three-dimensional guard 6 is provided on the absorber 4, more preferably, over the entire longitudinal direction of the absorbent article. A portion where the absorber 4 does not exist, that is,
In the waist portion 8 of the abdomen A and the back B of the diaper, the entire surface of the sheet material 61 is fixed to the topsheet 2.

The side edge 3a of the leak-proof sheet 3 is located on the back side of the absorber 4, and the side edge 3a is not located outside the disposable diaper more than the side edge 4a of the absorber 4.
Are arranged. In the present embodiment, the absorber 4 is disposed so as to be substantially at the same position as the side edge 4 a of the absorber 4. The outer layer nonwoven fabric 5 is disposed on the back side of the leak-proof sheet 3, and both the outer layer nonwoven fabric 5 and the sheet material 61 extend outward from the side edge 4 a of the absorber 4 toward the outer side of the disposable diaper. Issued
The extended outer non-woven fabric 5 and the sheet material 61 are laminated to form the leg portion 7 and thus the leg gather.
That is, the leg elastic member 71 is held and fixed by the outer nonwoven fabric 5 and the sheet material 61. In addition, outer layer nonwoven fabric 5
Has an hourglass shape with a central portion constricted and forms the outer shape of the diaper. The leak-proof sheet 3 and the absorber 4 have a rectangular shape and are arranged at the center of the outer nonwoven fabric 5. The topsheet 2 also has a rectangular shape, and extends outward from the diaper from both longitudinal edges of the absorber 4 and is laminated with the outer nonwoven fabric 5 to form a waist portion 8. Therefore, the waist elastic member 81 is held and fixed by the outer nonwoven fabric 5 and the topsheet 2.

The top sheet 2 is located on the front side of the leakage prevention sheet 3 and its side edge 2a is located at the side edge 4a of the absorber 4.
The base end 60 is formed by fixing a sheet material 61 to the topsheet 2 so as not to be located outside the disposable diaper. In the present embodiment, the side edges 2 a of the topsheet 2 are arranged so as to be located inside the side edges 4 a of the absorber 4. In FIG. 2, in order to make the base end 60 clear, for convenience, the sheet material 61 is described as being fixed to the top sheet 2 only at the base end 60. Outside the end 60, it is preferable that the entire surface is fixed to the topsheet 2 and the water-repellent mount 41.

The absorber 4 includes a diffusion sheet 43 disposed on the surface side of the absorption body 42, and includes a water-repellent backing sheet 41.
Is wound up above the diffusion sheet 43. In FIG. 2, the side edge 41a of the water-repellent backing paper 41 is
Rather than being located inside the disposable diaper. The distance between the side edge 41a of the water-repellent mount 41 and the side edge 42a of the absorbent main body 42 is preferably 0 to 60 mm in a disposable baby diaper. The distance between the diaper and the diaper is preferably 0 to 20 mm in the disposable diaper for babies. In addition, in the case of products having greatly different dimensions such as sanitary napkins and adult disposable diapers, the dimensions can be appropriately selected. The position and distance in the above description are the position and distance when the disposable diaper is viewed in a plan view, respectively.

The fastening tape 11 is fixed to the outer layer nonwoven fabric 5 at the fixing portion 11a. In the present embodiment, as shown in FIG. 1, a reinforcing sheet 12 is provided for reinforcement. ing. Reinforcement sheet 1
Numeral 2 is sandwiched and fixed between the outer layer nonwoven fabric 5 and the sheet material 61 via an adhesive.

The members other than the water-repellent backing in the disposable diaper of the present embodiment can be formed by using a forming material usually used for a disposable diaper without any particular limitation.

The disposable diaper 1 of the present embodiment is configured by using the absorbent article paper of the present invention as a mount for an absorbent body, and since the mount has high strength even when wet, It can exhibit sufficient strength without using other members, can reduce the amount of constituent materials used compared to conventional disposable diapers, and can arrange the mount as described above, from the side Can also be improved. By using the paper having such high strength and water repellency as the backing paper, as shown in FIG. 2, the use range of the leak-proof sheet can be kept to the minimum necessary range, and the leg portion and the like can be used. Since there is no need to provide a leak-proof sheet, air permeability can be improved, and stuffiness and rash can be efficiently prevented.

The disposable diaper 1 of the present embodiment can be obtained by manufacturing a disposable diaper having the above-described configuration by using a conventional method for manufacturing a disposable diaper without any particular limitation.

[0032]

Examples [Examples 1 to 4 and Comparative Examples 1 and 2] Paper was made from 100 parts by weight of bleached softwood kraft pulp (NBKP) to a basis weight of 20 g / m ^2. In the composition shown in Table 1, carboxymethyl cellulose (CMC) and AlCl ₃ as a polyvalent metal salt were
It was added by coating the paper by the coating method shown in Table 1 to obtain an absorbent article paper of the present invention. The wet strength of the resulting absorbent article paper was measured. The wet strength was measured as follows. The obtained paper is placed in the flow direction (M
A test piece having a width of 50 mm in D) and a length of 150 mm in a direction (CD) perpendicular to the flow direction was cut out. The test piece was brought into a wet state by contacting a sponge impregnated with water, and then using a Tensilon tensile tester (manufactured by Orientec Co., Ltd.) at a distance between chucks of 50 mm and a tensile speed in the CD direction of 300 mm / min. A tensile test was performed to measure the strength at break, and this was defined as wet strength.

Using the obtained absorbent article paper as a backing paper, a mixture of pulp / absorbent polymer is laminated on the paper,
An absorbent for an absorbent article was obtained. A porous wet sheet made of calcium carbonate / polyethylene (PE) is arranged as a leak-proof sheet under the obtained absorbent, and a nonwoven fabric made of polypropylene (PP) / PE composite fiber is used as a topsheet above the absorbent. The disposable diaper shown in FIGS. 1 and 2 was obtained. The obtained diaper was collected after the monitor test, the number of tears of the mount was counted, and the absorbent article paper was evaluated. Further, as comparative examples, papers were prepared by adding CMC in the amounts shown in [Table 1] and adding the metal ions shown in [Table 1], and evaluated similarly. In addition, the monitor test (practical test) was performed by providing 30 diapers to 10 monitors each and having them use the diapers in a normal use condition as usual.

[0034]

[Table 1]

Example 5 A rosin sizing agent was added as a sizing agent to the paper obtained in the above Example 2 in advance of 1.5 parts by weight based on 100 parts by weight of the paper. In the same manner as in Example 1, a water-repellent absorbent article paper was obtained. A disposable diaper as an absorbent article of the present invention was obtained in the same manner as in Example 2 except that the obtained absorbent article paper was used. The obtained disposable diaper was excellent in strength and leakage prevention performance because the used absorbent article paper had high wet strength and leakage prevention performance.

Example 6 In the paper made in Example 5, 100 parts by weight of fluff pulp (NBKP) was used.
A water-repellent absorbent article paper was obtained in the same manner as in Example 5, except that 100 parts by weight of the carboxymethylated pulp was mixed and used. Examples 5 and 6 were evaluated in the same manner as in Example 1. In each of the above embodiments, the NBK
Although the blend system using only P was shown, the hardwood bleached kraft pulp (L
BKP).

[0037]

The absorbent article paper of the present invention has high strength even when wet. Further, the absorbent article of the present invention can reduce the amount of the leak-proof sheet used, and is excellent in anti-sagging properties.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a disposable diaper as an absorbent article according to the present invention.

FIG. 2 is a sectional view schematically showing a section taken along line XX of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disposable diaper 11 Fastening tape 12 Reinforcement sheet 2 Top sheet 3 Leak-proof sheet 4 Absorber 41 Water-repellent mount 42 Absorption body 43 Diffusion sheet 5 Outer nonwoven fabric 6 Three-dimensional guard 60 Base end 61 Sheet material 63 Free end 64 Three-dimensional guard elastic member 7 leg part 71 leg elastic member 8 waist part 81 waist elastic member A belly side part B back side part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61F 13/514 A61F 13/18 320 13/15 D21H 17/63 // A61F 5/44 F term (reference) 2D036 HA55 3B029 BA05 BA13 BA17 BD12 BD13 BD14 BD16 4C003 CA10 4C098 AA09 CC12 CE06 DD11 DD30 4L055 AF10 AG07 AG46 AH23 AJ01 BE08 FA13 GA26

Claims (4)

[Claims] 1. An absorbent article paper comprising a fiber web containing carboxylated fibers and / or a carboxyl group-containing binder, containing a polyvalent metal salt that dissociates in water to form a trivalent metal ion. 2. The compounding amount of the polyvalent metal ion is based on the molar amount of the carboxyl group contained in the fibrous web.
2. The absorbent article paper according to claim 1, which is at least equimolar. 3. The absorbent article paper according to claim 1, further comprising a water repellent. 4. A liquid-permeable top sheet, a liquid-impermeable leak-proof sheet and a liquid-retentive absorber, and a three-dimensional guard for forming a three-dimensional guard is provided on both left and right edges in the longitudinal direction of the absorber. An absorbent article having a three-dimensional guard formed by disposing a sheet material, wherein the absorber includes a water-repellent backing sheet and an absorbent body, and the water-repellent backing sheet is the absorbent article according to claim 3. An absorbent article made of paper and disposed so that the left and right sides in the longitudinal direction cover the left and right sides in the longitudinal direction of the absorbent main body and are located on the left and right lateral edges on the front side of the absorbent main body.