JP2001214399A - Water disintegrable superabsorbent composite and absorbent article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite having biodegradability and excellent water absorbing ability and an absorbent article provided with the same. SOLUTION: By incorporating a water-absorbing resin into an absorbent core, a composite having excellent water-absorbing ability and easily treating waste and an absorbent article provided with the same can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-disintegrable superabsorbent composite and an absorbent article provided with the same.
The present invention relates to a water-disintegrable superabsorbent composite that exhibits excellent absorption properties when used and can be disposed of in a flush toilet when disposed, and an absorbent article including the same.

[0002]

2. Description of the Related Art [Technical background of disposable absorbent articles] Disposable absorbent articles are articles designed to efficiently absorb bodily fluids such as urine, blood, menstrual blood, and sweat. Napkins, incontinence pads, breast milk pads, medical underpads, surgical underpads, pet seats and the like.

[0003] Although such absorbent articles are widely used in the world because of their advantages such as being inexpensive and easy to use, there is a major problem in disposal after use. That is, such a problem is that used absorbent articles such as disposable diapers to which excrement adheres and sanitary napkins to which body fluid adheres are discarded at the same time as general waste.

[Technical Background of Disposable Absorbent Article Waste Disposal] Generally, disposable absorbent articles are intended to be disposed of after use. At present, they are discarded after use and incinerated as general combustible waste.

For example, as a method of disposing of disposable disposable diapers, the disposable disposable diapers are rounded so as to enclose the waste, and the rolled disposable diapers are fastened with a tape fastener or the like and discarded in a trash box or the like, and collected. It is common to incinerate such garbage.

However, storing excrement wrapped in a disposable diaper in a trash can or the like for a short period of time is not preferable because of bad smell and hygiene problems. Also, even outside the room, for example, disposable disposable diapers are left as garbage in parks, etc.
Environmental health problems are occurring.

On the other hand, when the excrement is stool at the time of use, a method of disposing the disposable disposable diaper by a user or a caregiver removes the disposable diaper from the user and removes a solid portion of excrement such as stool from the disposable diaper. After removing and flushing the toilet, the other part is generally treated as general garbage, so that the operation is very complicated. In addition, since such treatment is usually performed by attaching a disposable disposable diaper to the water of a toilet bowl and dropping it off, sticky stool such as loose stool is difficult to peel off from the diaper, and the stool is treated without being completely removed. In many cases. Further, operations such as removing the stool from the diaper may stain the hands of the processor, and in such a case, the essential merits of the disposable paper diaper are reduced as compared with a non-disposable diaper.

[0008] In addition, the disposable disposable diaper absorbs water from the toilet and becomes heavy during the treatment, and causes dripping. In addition, the disposable disposable diaper may cause the disposable diaper to accidentally flow into the toilet and cause the clogging of the water distribution pipe. There are also disadvantages.

Also, absorbent pads used by women, such as sanitary and vaginal napkins and diapers, are discarded after use by wrapping them in paper in a garbage bin or a filth bin placed in the toilet. Is the current situation.

[0010] However, there is a case where an unpleasant odor is generated and unpleasant or unsanitary during a lapse of time from disposal to disposal as garbage.

Further, in a public toilet or the like, the flush toilet flushes with water, causing a trouble such as clogging of a pipe.

[Technical background of water-disintegrable absorbent articles] Water-disintegrable sanitary articles, so-called flush napkins, are known. Among the moist wipes commonly referred to as baby osshirifuki, water-disintegrating wipes are known.

[0013] A commercial product in which a part of the diaper for children and the diaper for adults is made water-disintegrable, particularly a topsheet and a topsheet, is known (Japanese Patent Application Laid-Open No. 10-277087).

However, night-type napkins and children's diapers,
Although there is an idea that the absorbent material or the whole product for adult diapers is made water-disintegrable, there is no practical example. The reasons are roughly divided into two.

The first reason is a contradiction derived from stability in use and water disintegration function. In the case of conventional products, water disintegration imparts a sticky feel and tear during use, while trying to stabilize it causes a problem of instability of water disintegration, it can be said that it is an unfinished product .

The second reason is that most of the absorbent used is a product mainly composed of wood pulp, so that the bulk and weight of the target product are large. This requires the amount of water for uniform dispersion and the time required for diffusion and dissociation, and eventually leads to the tendency to close pipes and joints.

[Technical Background of Rinse Treatment of Disposable Absorbent Article Waste] As one of the solutions to this problem, it has been proposed to dispose of the disposable absorbent article waste in a flush toilet. To solve this problem, do not leak or wet when using, and after absorbing water and body fluids,
It is also required to have mechanical strength enough to withstand sufficient use and to be easily disintegrated when placed in a flush toilet.

[0018] These are completely contradictory properties, and a substance having both properties has not yet been provided.

Therefore, the layer forming the skin contact surface of the diaper (top sheet or top sheet provided on the top sheet) is made removable, and the sheet is removed and flushed with the excrement into the toilet. Disposable diapers that can be used have been proposed. For example, JP-A-5-3889 discloses a disposable diaper including a sheet in which an elastic member is combined with a water-soluble sheet. However, the sheet does not have wet strength enough to withstand the movement of the wearer after excretion and water dispersibility enough to be easily discarded in a toilet.

Further, Japanese Patent Application Laid-Open No. 5-179548 discloses a sheet satisfying wet strength and water dispersibility. However, since the unsaturated carboxylic acid-based polymer compound is used as the binder in the sheet, the residual monomer at the time of polymerization may irritate the skin, or may discolor during long-term storage because of the unsaturated compound. Cheap.

That is, an absorbent article in which all the constituent materials have water disintegrability, a practical topsheet and an absorbent article in which the absorbent has water disintegration, or an absorbent article in which the absorber has water disintegration are: Not reported so far.

[Technical Background of Biodegradable Materials Constituting Disposable Absorbent Articles] Disposable sanitary goods wastes include a top sheet made of a nonwoven fabric or a porous molded polyethylene film or a polypropylene film material, a back sheet made of polyethylene, It is composed mainly of an absorbent core in which a water absorbent resin is dispersed in pulp. In these materials, in particular, the back sheet does not have biodegradability because a synthetic resin such as polyester, polypropylene, or polyethylene or a synthetic fiber is partially used in order to maintain waterproofness. Also, the materials described in the above publication have water disintegration properties but do not have biodegradability, so they do not biodegrade after disintegration. The waste will remain without being decomposed at the terminal treatment plant.

[Technical background of thinning disposable hygiene articles] Absorbent main components used in absorbent products for absorbing moisture and body fluids are fluffy wood pulp and so-called polymer absorbents (hereinafter referred to as “SAP”). ).)). However, in recent years, in order to improve logistics efficiency, improve shelf efficiency at retail stores, and save resources, the conventional relatively bulky absorbent products have become thinner and more compact. Social demands have grown.

As means for downsizing and thinning, S
In the combination of AP and pulp, 2 to 2
Increasing the ratio of SAP, which has about 10 times higher water absorption capacity, and decreasing the ratio of pulp will make it thinner and more compact. Ultimately, a 100% SAP structure will pursue maximum thinness and compactness. it can.

Further, when the waste is poured into the flush toilet, the disintegration of the pulp is so poor that it is likely to cause clogging of pipes and the like. That is, it is indispensable that the sanitary goods that can be flushed into the flush toilet use a small amount of pulp or have a pulp press (no pulp) structure.

However, as the SAP ratio increases,
In the case of water absorption, based on the properties of SAP,
Since the “gel blocking phenomenon” occurs and the absorbent product does not function with the calculated efficiency, the conventional technology limits the configuration of SAP / pulp to about 1/1, and SAP / pulp = (3 / 1) or more = 3 or more, and further, it is an extremely difficult technical task to increase the SAP ratio to take a pulp press structure close to SAP 100%.

Here, the term “pulpless” is used in accordance with the concept generally applied in this field and SAP.
Pulp ratio (SAP / pulp) is one or more.

Of course, there have been various challenges regarding the pulp press structure. For example, a method of producing a fibrous, web-like SAP sheet by direct spinning or partial hydrolysis of an acrylic acid-based fiber, impregnating a web with a monomer such as acrylic, and polymerizing it with ultraviolet rays or an electron beam. Various attempts have been made such as a method for producing a web-like water-absorbing polymer, or a method for producing a sheet-like water-absorbing polymer by carboxymethylating a non-woven fabric such as cellulose and then partially cross-linking the non-woven fabric.

However, there have been no reports of industrially and economically successful cases due to the problem of material cost and a large amount of capital investment.

[Demand for Disposable Absorbent Articles] There has been a great demand for thinner disposable absorbent articles and waste disposal, and there has been a strong demand for the emergence of new disposable sanitary materials including the treatment method.

[0031]

SUMMARY OF THE INVENTION In contrast to a conventional thin absorbent made of a mixture of fluff pulp and SAP mixture, the present invention is based on a water-absorbent resin which hardly uses fluff pulp and has a weight and bulk of 1%. / 2 or less, in some cases 1 /
The present invention relates to a highly water-absorbent composite having an absorbency of 3 or less and an absorbent article to which the composite is applied and used.

That is, an object of the present invention is to provide a water-disintegrable superabsorbent composite which is excellent in absorption characteristics and which is thin when used for sanitary materials and the like, and a method for producing the same.

Another object of the present invention is to provide a method for treating the waste of the water-disintegrable superabsorbent composite according to the present invention.

[0034]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, completed the present invention.

That is, the present invention is specified by the following items.

(1) An absorbing component (A component) mainly composed of a water absorbing resin, a support component (B component) carrying the absorbing component (A component), the mutual water absorbing resin and the water absorbing component A superabsorbent composite comprising a reactive resin and a binding component (C component) for binding the support component, wherein the absorbent component (A component), the support component (B component), and the A water-disintegrable superabsorbent composite, wherein the binding component (C component) has water dispersibility.

(2) The water-disintegrable superabsorbent complex according to (1), wherein the absorbing component (A component) comprises biodegradable crosslinked polyamino acid particles.

(3) The water-disintegrable superabsorbent composite according to (1), wherein the support component (component B) is a tissue mat composed of wood pulp fibers.

(4) The support component (component B) is composed mainly of wood pulp fibers, and has a fiber length of 25.
The water-disintegrable superabsorbent composite according to (1), wherein fibers having a diameter of not more than mm are formed into a mixed sheet.

(5) The support component (component B) is mainly composed of cellulose fibers selected from the group consisting of rayon, cotton, and lyocell having a fiber length of 25 mm or less, and comprises polyvinyl alcohol or partially crosslinked polyvinyl alcohol. The water-disintegrable superabsorbent composite according to (1), further comprising a binder made of a substance.

(6) The support component (component B) is mainly composed of cellulose fibers selected from the group consisting of rayon, cotton and lyocell having a fiber length of 25 mm or less, and is an alkaline earth metal of carboxymethyl cellulose. The water-disintegrable superabsorbent composite according to (1), further comprising a binder made of a salt.

(7) The binding component (C component) is 250
The water-disintegrable superabsorbent composite according to (1), comprising a microfibrillar cellulose having a water retention of not less than 10%.

(8) The water-disintegrable superabsorbent composite according to (1), wherein the binding component (component C) comprises microfibrillated cellulose obtained by highly disintegrating wood pulp. .

(9) The water-disintegrable superabsorbent composite according to (1), wherein the binding component (C component) comprises bacterial cellulose (BC).

(10) An absorbent article comprising a liquid-permeable top sheet, an absorbent having liquid absorbing / liquid retaining properties, and a liquid-impermeable back sheet, wherein the absorbent is (1) An absorbent article comprising the water-disintegrable superabsorbent composite according to any one of the preceding claims.

(11) The absorbent article according to (10), wherein the topsheet is a water-disintegrable sheet.

(12) The absorbent article according to (10), wherein the back sheet comprises a water-disintegrable sheet.

(13) The absorption component (A component), the support component (B component), and the binding component (C component) have biodegradability.
The absorbent article according to any one of (12).

(14) The surface sheet and the absorber both have biodegradability (10) to (10).
The absorbent article according to any one of (13).

(15) The absorbent article according to any one of (10) to (14), wherein the top sheet, the absorber, and the back sheet all have biodegradability.

(16) Any of (10) to (15), wherein the topsheet is composed mainly of wood pulp fibers, and is a sheet formed by mixing fibers having a fiber length of 25 mm or less. An absorbent article according to any of the above items.

(17) The top sheet has a fiber length of 25 m
(10) to (10) to (10) to (1), which are mainly composed of cellulose fibers selected from the group consisting of rayon, cotton, and lyocell having a molecular weight of m or less, and contain a binder composed of polyvinyl alcohol or a partially crosslinked product thereof. 1
The absorbent article according to any one of 5).

(18) The top sheet has a fiber length of 25 m
(10) characterized by being composed mainly of a cellulose fiber selected from the group consisting of rayon, cotton, and lyocell having a molecular weight of m or less, and containing a binder composed of an alkaline earth metal salt of carboxymethyl cellulose.
The absorbent article according to any one of (1) to (15).

(19) The back sheet is formed of a joined body of a tissue-like mat made of a polyvinyl alcohol film and wood pulp fibers (10) to (10).
The absorbent article according to any one of (15).

(20) The back sheet is composed of a polyvinyl alcohol film and wood pulp fibers as main components, and is a sheet formed by mixing and molding fibers having a fiber length of 25 mm or less. (1
The absorbent article according to any one of (0) to (15).

(21) The back sheet is composed mainly of a polyvinyl alcohol film and a cellulose fiber selected from the group consisting of rayon, cotton, and lyocell having a fiber length of 25 mm or less, and comprises polyvinyl alcohol or a partially crosslinked polyvinyl alcohol. The absorbent article according to any one of (10) to (15), wherein sheets formed by a binder made of a material are joined.

(22) The back sheet is composed mainly of a polyvinyl alcohol film and cellulose fibers selected from the group consisting of rayon, cotton and lyocell having a fiber length of 25 mm or less, and an alkaline earth metal of carboxymethyl cellulose. (10) The absorbent article according to any one of (10) to (15), wherein a sheet formed by bonding a salt with a binder is bonded.

(23) The absorbent article according to any one of (10) to (15), wherein the absorbent is removably arranged.

(24) The absorbent body and the topsheet are removably arranged.
The absorbent article according to any one of (15).

(25) Liquid-permeable topsheet and liquid-absorbent
An absorbent body having a liquid-retentive absorbent body and a liquid-impermeable back sheet, and at least partially joined to the absorbent body, and surrounding the waist from the abdomen of the wearer when wearing the absorbent body part; In the absorbent article, which is provided with a wear state worn by a wearer and an exterior member that maintains the wear state, the top sheet, the absorber and the back sheet are integrally and detachably disposed. The absorbent article according to any one of (10) to (15).

(26) Liquid-permeable topsheet and liquid-absorbent
An absorbent body having an absorbent body having a liquid retaining property and a liquid-impermeable back sheet, the absorbent body being joined at least in part to the absorbent body, and surrounding the waist from the abdomen of the wearer when worn; An exterior member to be held against the wearer, the opposite side edges of the front body and the rear body of the exterior member are joined to form a waist opening and a pair of leg openings, In an absorbent article in which a stretchable elastic member is arranged along a portion, the absorber main body is disposed so as to be detachable from the outside (23) to (23).
The absorbent article according to any one of (25).

(27) Liquid-permeable topsheet and liquid-absorbent
An absorbent article using a disposable absorbent body composed of an absorbent having a liquid retaining property and a liquid-impermeable back sheet and a wash-resistant cover for holding or covering the absorbent body, wherein a part of the absorbent is used. Or, the absorbent article according to any one of (23) to (25), wherein all have water disintegration properties.

(28) In an absorbent article using the disposable absorbent body in combination with a wash-resistant cover, the disposable absorbent body is attached and detached from the outside while the cover is always worn. The absorbent article according to (27), wherein the absorbent article is arranged as possible.

[0064]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

(1) Preferred characteristics of the water-disintegrable superabsorbent composite of the present invention The feature of the water-disintegrable superabsorbent composite of the present invention is that the constituent materials exhibit not only the water-absorbing ability and the function of thinning, but also more. In order to promote the decomposition efficiently, the structure has been devised so that it can easily collapse.

That is, the water-disintegrable superabsorbent composite of the present invention is a composite having both <absorbency>, <water-disintegrable>, and <thin>. Further, <degradability> can be imparted by using a biodegradable material.

The preferred form of these performances in the present invention will be described in detail.

(1-1) Water disintegrability of the water-disintegrable superabsorbent composite The expression “water-disintegrable” in the water-disintegratable superabsorbent composite of the present invention is sometimes and sometimes referred to as a product after use in a toilet. The term "water-washing" or "flashable" is also used to describe the processing. Products having such water disintegration performance will be referred to as water disintegrable articles.

The requirements for exhibiting the water disintegration property are, for example, that when the material comes into contact with water in a toilet bowl, its constituent materials are dispersed as uniformly as possible in the water, and when it is discharged, it is physically connected to a pipe or the like. It is necessary that the occlusion does not cause a major occlusion and that the occlusion does not occur due to partial remaining. Actually, water disintegration proceeds in the following process. That is, <contact with water> → <diffusion and penetration of water> → <dissociation into water> → <dispersion in water>. In a word, the present inventors describe such a process as water disintegration.

(1-2) Absorbency of the water-disintegrable superabsorbent composite The water-disintegrable superabsorbent composite of the present invention is required to be excellent in water absorption as an absorbent. In particular, it is preferable that the amount of water absorption under load is large, the water retention capacity under load is large, and the water absorption speed is high.

For example, a sanitary material must be able to absorb various body fluids sufficiently, but in the present invention, physiological saline is used as a standard for body fluid, and the water-absorbing ability of a water-absorbing resin is represented.

That is, the water-disintegrable superabsorbent composite of the present invention preferably has at least one of the following water absorbing capacities. (1) Water absorption ability at an absorption rate of 0.1 to 50 ml / sec · cm ² when absorbing 20 ml of physiological saline. (2) When saturated saline is absorbed,
Water absorption capacity of 0.1 to 5 g / cm ² . (3) 20 ml of physiological saline was added to 103 kPa (20 g /
(cm ² ) a water absorption capacity when absorbed while applying a load of 0.05 to 4 g / cm ² . (4) 111 kPa after saturated absorption of physiological saline
Water absorption capacity with a return drainage of 0 to 7 g / cm ² when a load of (1 ton / m ² ) is applied.

Further, it is more preferable to have at least one of the following water absorbing capacities. (1) Water absorption capacity in which the absorption rate when absorbing 20 ml of physiological saline is 1 to 50 ml / sec · cm ² . (2) When saturated saline is absorbed,
Water absorption capacity of 1 to 5 g / cm ² . (3) 20 ml of physiological saline was added to 103 kPa (20 g /
(cm ² ) a water absorption capacity of 0.5 to ⁴ g / cm ² when absorbed while applying a load. (4) 111 kPa after saturated absorption of physiological saline
(1 ton / m ² ) Water absorption capacity with a return drainage of 0 to 5 g / cm ² when a load of 1 ton / m ² is applied.

There is no upper limit to these properties, and those showing high numbers except for (4) are preferable. However, the above numerical ranges are preferable as long as the composite can be actually produced.

As a preferred embodiment of the present invention, an upper limit is set for these values. When the composite of the present invention is used as a sanitary material, if the composition is the same as that of the composite of the present invention, a higher performance may be obtained. Can be used.

(1-3) Degradability of the water-disintegrable superabsorbent composite The water-disintegrable superabsorbent composite of the present invention is characterized by water disintegration. By being composed of this material, it will biodegrade even after being released into the environment and will not remain.

The term “degradability” included in the characteristics of the water-disintegrable superabsorbent composite of the present invention means that the disintegrated product after the above-described composite disintegrates in water is decomposed by microorganisms or the like.

Specifically, it is "biodegradable", but other than these, as long as the expression of the function of the water-disintegrable superabsorbent complex of the present invention is not hindered, The properties can be used for disposal. For example,
High temperature decomposability, oxidative decomposability, reductive decomposability, hydrolyzability, alkali decomposability, acid decomposability and the like can be mentioned.

“Biodegradable” means that the constituent material is decomposed by a bio (organism) such as a microorganism, a bacterium, an enzyme or the like in a natural environment or under artificially controlled conditions such as compost. Indicates that it is a low molecule.

(2) Structure of absorbent article containing water-disintegrable superabsorbent composite The present invention relates to a water-disintegrable superabsorbent composite and an absorbent article containing the same. The structure is divided into the following three parts depending on the portion that is water-disintegrable.

(2-1) Absorbent article having water disintegration as a whole (2-2) Absorbent article in which surface sheet and absorber have water disintegration (2-3) Only absorber has water disintegrating property Absorbent article having durable as used herein means "durable", that is, "can be repeatedly used at least several times by washing". Also, the disposable used here means "disposable", that is, "one-way use, which is not used once, processed and reused." Alternatively, when the constituent material has biodegradability, it can be treated by composting and burying.

That is, due to the fact that the water-disintegrating portions are different, their handling methods and waste treatment methods are also different. Hereinafter, these handling methods and processing methods will be described in detail.

(2-1) Absorbent article having water-disintegrable property as a whole Among the absorbent articles having the water-disintegrable superabsorbent composite of the present invention, an absorbent article having a water-disintegrable property as a whole Is
For example, there are the following two types, such as examples of diapers for children and adults.

(A) a diaper in which the entire structure of the diaper has water disintegration properties; (b) a combination of a durable cover portion and a relatively simple water disintegrable diaper having a simple structure. When having a property, for example, a water-disintegrable surface sheet as a surface sheet, the water-disintegrable superabsorbent composite of the present invention as an absorber,
As the back sheet, a water-disintegrable back sheet is exemplified.

As a specific example of the water-disintegrable surface sheet, wood pulp fiber is mainly used and the fiber length is 2
5 mm or less fiber mixed sheet, fiber length 25
mm or less rayon, cotton, and a cellulose fiber selected from the group consisting of lyocell as a main component, and a binder comprising polyvinyl alcohol or a partially crosslinked product thereof, and rayon having a fiber length of 25 mm or less, Examples thereof include those composed mainly of cellulose fibers selected from the group consisting of cotton and lyocell, and containing a binder composed of an alkaline earth metal salt of carboxymethyl cellulose.

Specific examples of the water-disintegrable back sheet include a sheet-like mat of a polyvinyl alcohol film and a wood pulp fiber, a polyvinyl alcohol film and a wood pulp fiber as main components, and A sheet obtained by mixing and forming a fiber having a fiber length of 25 mm or less is joined, and a polyvinyl alcohol film and a rayon having a fiber length of 25 mm or less, cotton, and a cellulose fiber selected from the group consisting of lyocell are constituted as main components, and , Comprising polyvinyl alcohol or a partially crosslinked product thereof, and a polyvinyl alcohol film and rayon having a fiber length of 25 mm or less,
Examples thereof include those composed of a cellulose fiber selected from the group consisting of cotton and lyocell and a main component, and a sheet formed by bonding an alkaline earth metal salt of carboxymethylcellulose with a binder.

(B) is a combination of a durable cover portion and a pad-type diaper obtained by further simplifying the diaper of (a). As the configuration of the pad-type diaper, one having the same diaper function as the above (a) is used.

(2-2) Absorbent article in which the topsheet and the absorber have water disintegration properties Among the absorbent articles provided with the water disintegrable superabsorbent composite of the present invention, the topsheet and the absorbent are made of water. There are the following two types of absorbent articles having disintegration properties.

(A) Combination of a diaper having a durable cover and a water-disintegrable topsheet / absorber In this case, the leak-proof function of the back sheet is left to the durable cover, and this type of diaper is washed by washing. Used repeatedly.

(B) Combination of a disposable cover portion and a diaper having a water-disintegrable topsheet / absorber In this case, the leak-proof function of the back sheet is left to the disposable cover portion, and this type of diaper has a binding component. The waste is treated as waste including the above.

(2-3) Absorbent article in which only absorbent has water disintegratability Among the absorbent articles provided with the water disintegrable superabsorbent composite of the present invention, only the absorbent has water disintegrable properties. There are the following two types of absorbent articles.

(A) a diaper in which a water-disintegrable superabsorbent composite is inserted as an absorber between a durable topsheet and a durable waterproof cover section; (b) absorption between the disposable topsheet and the disposable waterproof cover section Diapers with a water-disintegrable superabsorbent composite inserted as a body (3) Structure of the water-disintegrable superabsorbent composite The case where the property is given will be described separately.

(3-1) Structure of the water-disintegrable superabsorbent composite that does not impart biodegradability The structure of the water-disintegrable superabsorbent complex that does not impart biodegradability according to the present invention comprises a substrate, SAP, It consists of a combination of binders. The structure is not particularly limited, but examples are shown in Table 1.

[0094]

[Table 1] That is, the base material has water dispersibility or water easily dissociating property, and water disintegration property such as carboxymethylcellulose salt sheet, wood pulp thin leaf sheet, shortcut water entanglement sheet, shortcut water entanglement / carboxymethylcellulose salt, etc. Hot-water-soluble sheet such as sheet, PVA fiber sheet, cellulase-treated cellulose nonwoven fabric (T
Easily decomposable sheets (enzyme pretreatment) such as CF, benlyse), pH-dependent sheets such as cationic pulp, water-disintegrable / synthetic fiber shortcut composites such as carboxymethylcellulose salt sheet / PET shortcut (needle punch), PVA net / Hot water easily soluble / rayon shortcut (needle punch) / synthetic fiber shortcut complex.

Examples of the SAP include a partially neutralized product of a crosslinked polyacrylic acid, a partially hydrolyzed product of a starch-acrylonitrile copolymer, a starch-acrylic acid graft copolymer, and a hydrolyzed product of a vinyl acetate-acrylic ester copolymer. Decomposition products,
Examples thereof include a crosslinked copolymer of 2-acrylamide-2-methylpropanesulfonic acid and acrylic acid, a crosslinked product of a cationic monomer, a crosslinked isobutylene-maleic anhydride copolymer, and the like.

The binder has water dispersibility or water dissociation properties, and examples thereof include MFC, BC, PVA, and fibril acetate.

(3-2) Structure of the water-disintegrable superabsorbent composite imparted with biodegradability The structure of the water-disintegrable superabsorbent composite imparted with biodegradability of the present invention comprises a biodegradable substrate. , A biodegradable SAP and a biodegradable binder. The structure is not particularly limited, but examples are shown in Table 2.

[0098]

[Table 2] That is, as a biodegradable substrate, those having both water dispersibility or water easily dissociable, carboxymethyl cellulose salt sheet, thin sheet of wood pulp, water entangled sheet of shortcut rayon, water entangled sheet of shortcut rayon and Of water-disintegrable sheet such as carboxymethylcellulose salt, cellulase-treated TC
F, processed sheets of enzyme pretreatment such as benlyse and the like.

The biodegradable SAP includes, for example, cross-linked carboxymethyl cellulose, cross-linked starch, cross-linked amino acid and the like. Particularly desirable is a cross-linked amino acid SAP, which is described in detail below.

As the biodegradable binder, those having both water dispersibility and water dissociation property are used.
C, biodegradable fibril acetate and the like.

(4) Application to Absorbent Articles and Embodiments The absorbent articles of the present invention can be described in a comprehensive expression as follows.

The application of the water-disintegrable superabsorbent composite of the present invention to an absorbent article and its embodiments are not particularly limited. For example, the embodiment shown in FIG. 1 can be used.

Among these, the absorbent article (2-1) which is entirely disintegratable as described in (2) can be treated by flushing it into a flush toilet after use. . On the other hand, the absorbent article (2-2) in which the topsheet and the absorbent have water disintegration properties and the absorbent article (2-3) in which only the absorbent has water disintegration properties are used by flushing a used portion to a flush toilet or the like. Process by flowing. Here, the removal of the used portion may be performed in a worn state, or may be performed in a state in which the entire part is once removed. The case of removing the used absorbent portion from the outside in the wearing state will be described in (5).

(5) A diaper whose used absorbent portion can be detached from the outside in a worn state In an absorbent article using the water-disintegrable superabsorbent composite of the present invention, removal of the used absorbent portion in a worn state Possible diapers can be divided into cut-off and detachable types.

First, FIG. 1 will be described. FIG. 1 (a)
Is an example in which only the absorbent has water disintegration properties and the top sheet does not have water disintegration properties. In this case, the embodiment example in which the absorbent after removing the topsheet after use is taken out and flowed to the flush toilet is shown. In the case of urine treatment, the topsheet may be treated separately, but in the case of stool treatment, it is necessary to once dispose of the stool in the toilet and then treat the topsheet separately.

FIG. 1 (b) shows an embodiment in which both the topsheet and the absorber have water disintegration properties. After use, the topsheet and the absorber can be flushed together into a flush toilet. . In the case of stool treatment, the stool can be flushed with the stool attached to the topsheet.

FIGS. 1C and 1D have a structure in which the cover and the absorber can be separated, and the cover may be durable or disposable. The absorbent part to be separated is composed of only the water-disintegrable superabsorbent composite, and the water-disintegrable superabsorbent composite is bonded to the topsheet, backsheet, or adhesive, elastic material, etc. In some cases, this is indicated as the absorber body as shown in the figure, including both cases. In cases (c) and (d), if the entire absorbent body has water disintegration properties, it can be discarded in a toilet after use. However, in the case of (c), the absorber main body is stored inside, and the absorber main body is separated in a state where the entire cover is opened. On the other hand, in the case of (d),
Although the absorbent body is stored inside the cover, the absorbent body can be taken out with a part of the cover opened. In this case, if a new absorbent body is reloaded while being worn and reconnected, it can be used repeatedly until the cover is contaminated.

Next, the cutout type will be described. The cutout type can be divided according to the cutout portion, and there are cases where the cutout portion is only the absorber, the absorber + top sheet, the absorber + backsheet, the absorber + topsheet + backsheet. The water-disintegrating portion of the cut portion can be flushed to the toilet. The processing of other parts is not particularly limited, but a processing method can be selected according to a constituent material. For example,
The absorbent removed according to the configuration described in detail in (4) may be flushed to a flush toilet, and the other may be incinerated together with general waste.

In the case of FIG. 2A, the whole is a disposable trousers-type diaper, and the absorbent body can be separated from the entire diaper by a separating line. When the discharge of urine, stool, etc. is confirmed, the part may be separated in a worn state and processed, and then the remaining part which is not contaminated or less contaminated may be processed. (B) is an application example of (a).
An example of an embodiment for removing a site where urine or stool adheres is shown. In the figure, the stool processing mesh sheet is an example in which a nonwoven fabric having a mesh structure for separating urine and stool is combined.

The example of FIGS. 3 and 4 is an example of an embodiment comprising a constantly worn portion and a detachable disposable portion, which can be attached or detached from the outside. FIG.
(A) restricts the always worn portion to the waist portion, and the other portions, namely, the top sheet, the back sheet,
An absorber main body including a binding zipper elastic portion is detachable.

FIG. 3B shows an example in which the constantly worn portion includes the waist portion and both legs, and the absorbent body including the binding device, which is a disposable portion, is made detachable. In the case of FIG. 3, the case where the always worn portion is durable and the case where it is disposable are considered.

FIG. 4 shows an embodiment in which a specially designed undergarment is prepared in which the constantly worn portion is durable. FIG. 4 (a) shows an example in which the disposable absorbent body is detachably attached to the girdle-shaped always worn portion. . The absorbent body has a magic tape piece at both ends and side portions as a binding function.

In (b), (c) and (d), special panties or shorts having a sufficient opening through which urine and stool can pass are always worn as wearing parts, and the openings are covered. It shows an example in which an absorbent body having the ability to absorb urine and feces is detachably combined. (B) is a case where the opening is present as it is, (c) is a hydrophobic portion such as polyethylene, polypropylene or PET having a 10-20 mesh equivalent portion which is involved in urine excretion in almost the first half of the opening. This is an example in which a fiber filament net is attached. (D) is an example in which the filament net is attached to the entire opening. This filament net allows the urine, and possibly most of the stool, to permeate the net and migrate to the absorber, preventing the adherence of exudates to the skin, and also acts as a topsheet. For this reason, it is desirable that the constituent material be subjected to an anti-dirt prevention process or a water-repellent process using silicon, Teflon, or the like and have a so-called stain-free (stain-free effect).

(6) Basic structure of the water-disintegrable superabsorbent composite The present invention relates to a water-disintegrable superabsorbent composite,
The "absorbing component (component A)" mainly composed of a water-absorbing resin, the "support component (component B)" carrying the same, and the "binding component (component C) which binds the water-absorbing resin to each other and the support. ) ".

In the water-disintegrating superabsorbent composite of the present invention, the “absorbing component (component A)” is defined as (7), the “support component (component B)” is defined as (8), and the “binding component (component C)”. )) Will be described in detail in (9).

(7) Absorbing component (A component) of the water-disintegrable superabsorbent composite (A component)
Is composed of a "water-absorbent resin" or a composite in which at least a part of the surface of the "water-absorbent resin" is coated with "microfibrillar cellulose".

The “microfibrillar cellulose” is common to the “binding component” in (9), and therefore the details will be described in (9). The water-absorbent resin is (7-1)
Next, the water-absorbing resin having biodegradability will be described in (7-2).

In the present invention, the “water-absorbent resin” has a structure in which at least a part of the surface is covered with microfibrillar cellulose, and is one of the important factors capable of exhibiting a thin function.

(7-1) Water-absorbing resin The water-absorbing resin used in the water-disintegrable superabsorbent composite of the present invention is not particularly limited. JP-A-55-84304, U.S. Pat. No. 4,625,001), a partially hydrolyzed starch-acrylonitrile copolymer (JP-A-46-43).
No. 995), a starch-acrylic acid graft copolymer (JP-A-51-125468), and a hydrolyzate of a vinyl acetate-acrylic acid ester copolymer (JP-A-52-128).
No. 14689), copolymerized crosslinked product of 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid (EP 0068189), crosslinked product of a cationic monomer (US Pat. No. 4,906,717), cross-linked isobutylene-anhydride Maleic acid copolymer (US Pat. No. 4,389,389)
No. 513).

These resins may be used as a mixture of two types.

The amount of the water-absorbing resin used in the present invention varies greatly depending on the type and amount of the body fluid for the purpose of absorption, and also depends on the intended use. Generally, the amount is preferably from 1.0 to 500 g, and particularly preferably from 1 to ²⁰⁰ g, per m2 of the sheet.

The shape of the water-absorbing resin used in the present invention may be irregular pulverized, spherical, granular, granular, granulated, flake,
Various forms such as a lump, a pearl, a fine powder, a fiber, a rod, a film, and a sheet can be used, and a preferable shape can be adopted depending on the application. Further, it may be a fibrous base material, a porous material, a foam, or a granulated material.

The particle size of these water-absorbing resins is not particularly limited, but depends on the intended use. For example,
In the case of disposable diapers, since it is desired that a high absorption rate and gel blocking do not occur, the average particle diameter is preferably 70 to 1000 μm, and 100 to 500 μm.
Is more preferred.

The water-absorbing resin used in the absorbent article of the present invention needs to have excellent water-absorbing ability. In particular, it is necessary that the water absorption under a non-load is large, the water absorption under a load is large, the water retention under a load is large, and the water absorption speed is high.

For example, the sanitary material must be able to absorb various bodily fluids sufficiently. In the present invention, physiological saline is used as a standard for bodily fluids, and the water-absorbing ability of the water-absorbing resin is expressed.

That is, the water absorbing resin used in the absorbent article of the present invention preferably has the following water absorbing ability. (1) water absorption capacity in which the equilibrium swelling and absorption of physiological saline is 20 to 200 times per unit weight of the dry polymer, (2)
(3) a water absorption capacity in which physiological saline is absorbed for 1 minute and the amount of absorption is 10 to 150 times per unit weight of the dry polymer;
The amount of physiological saline absorbed under a load of 103 kPa (20 g / cm ² ) is 5 to 150 per unit weight of the dry polymer.
(4) The water retention capacity that can be maintained after applying a centrifugal force of 3000 G for 10 minutes to the gel saturated with physiological saline is 5 per unit weight of the dry polymer.
It has at least one of the water absorption capacities of up to 150 times.

Further, those having the following water absorbing ability are more preferable. (1) water absorption capacity in which the equilibrium swelling and absorption of physiological saline is 30 to 200 times per unit weight of dry polymer, (2)
(3) a water absorption capacity in which a physiological saline solution is absorbed for 1 minute and the absorption amount is 20 to 150 times per unit weight of the dry polymer;
The amount of physiological saline absorbed under a load of 103 kPa (20 g / cm ² ) is 5 to 150 per unit weight of the dry polymer.
(4) The water retention capacity that can be maintained after applying a centrifugal force of 3000 G for 10 minutes to the gel saturated with physiological saline is 5 per unit weight of the dry polymer.
It has at least one of the water absorption capacities of up to 150 times.

Although there is no upper limit to these values, those showing high numbers are preferable, but the above numerical ranges are preferable as long as a water-absorbent resin can be actually produced.

As a preferred embodiment of the present invention, these values are provided with upper limits. However, it is not impossible to use a resin having higher performance as the sanitary material of the present invention.

(7-2) Water-absorbing resin having biodegradability On the other hand, in recent years, biodegradable polymers have attracted attention as “earth-friendly materials”, and it has been proposed to use this as a water-absorbing resin. I have.

Examples of the biodegradable water-absorbing resin used in such applications include cross-linked polyethylene oxide (Japanese Patent Laid-Open No. 6-157795), cross-linked polyvinyl alcohol, cross-linked carboxymethyl cellulose (US Japanese Patent No. 4650716), cross-linked alginic acid, cross-linked starch, cross-linked polyamino acid and the like are known.

On the other hand, a resin obtained by cross-linking a polyamino acid is biodegradable and thus is friendly to the global environment. Even if absorbed in a living body, it is digested and absorbed by enzymatic action and exhibits antigenicity in the living body. It has been shown that the decomposition products have no toxicity, so it is a material that is gentle to humans.

The crosslinked polyamino acid is not particularly limited, and a partially crosslinked polyamino acid can be used. The basic skeleton of the polyamino acid used in the present invention comprises a polypeptide in which amino acids are dehydrated and condensed. Specific examples of the amino acid component include, for example, 20 kinds of essential amino acids, L-ornithine, a series of α-amino acids, β-alanine, γ-aminobutyric acid, neutral amino acids, acidic amino acids, ω-esters of acidic amino acids, bases N of basic amino acids and basic amino acids
Amino acids and amino acid derivatives such as substituted products, aspartic acid-L-phenylalanine dimer (aspartame);
Examples thereof include aminosulfonic acids such as L-cysteic acid. α-amino acids are optically active forms (L-form, D-form)
Or a racemic form.

Further, the polyamino acid may be a copolymer containing other monomer components. Examples of the monomer component of the copolymer include aminocarboxylic acid, aminosulfonic acid, aminophosphonic acid, hydroxycarboxylic acid, mercaptocarboxylic acid, mercaptosulfonic acid, and mercaptophosphonic acid.

Further, polyamines, polyhydric alcohols, polythiols, polycarboxylic acids, polysulfonic acids, polyphosphonic acids, polyhydrazine compounds, polycarbamoyl compounds, polysulfonamide compounds, polyvalent sulfonamide compounds, Phosphonamide compounds, polyepoxy compounds, polyvalent isocyanate compounds, polyvalent isothiocyanate compounds, polyvalent aziridine compounds, polyvalent carbamate compounds, polyvalent carbamic acid compounds, polyvalent oxazoline compounds, polyvalent unsaturated bonds Compounds, polyvalent metals and the like.

When it is a copolymer, it may be a block copolymer or a random copolymer. Further, it may be a graft copolymer.

Among these, polyaspartic acid, polyglutamic acid,
It is preferable to use polylysine as the basic skeleton, and it is preferable to use polyaspartic acid and glutamic acid having high water absorption as the basic skeleton, and particularly preferable is polyaspartic acid suitable for industrial production.

Regarding the side chain structure of the cross-linked polyamino acid used in the complex of the present invention, even a polyamino acid residue having no substituent has a pendant group derived from the polyamino acid residue. It does not matter. In the case of polyaspartic acid, it is a group having a carboxyl group in a structure in which an imide ring is simply opened, but other substituents may be introduced.

For example, there are a group having a carboxyl group in a structure in which an imide ring is simply opened, an amino acid residue such as lysine, a pendant group having a carboxyl group, and a pendant group having a sulfonic acid group. Where the carboxyl group,
In the case of a sulfonic acid group, a salt may be used. Examples of the counter ion of the carboxyl group include alkali metal salts, ammonium salts, and amine salts.

In the case of an acidic polyamino acid, the carboxyl group or side chain group is located at the β-position with respect to the amide bond of the polymer main chain. It may be substituted, and in the case of a glutamic acid residue, it may be substituted at the α-position or at the γ-position.

In the case of a copolymer, in the case of polyaspartic acid and its copolymer, the amino group of aspartic acid or the copolymer monomer and the carboxyl group at the α-position of aspartic acid are combined with α. It is a bond, and when it is bonded to the carboxyl group at the β position of aspartic acid, it is a β bond.

In the case of polyaspartic acid, the α-linkage and β-linkage are not particularly limited, and the binding mode is not particularly limited. It may be only an α bond, only a β bond, or a mixture.

The binding portion between the basic skeleton and the side chain portion of the polyamino acid of the present invention is not particularly limited. In the case of an acidic polyamino acid, it is an amide bond, an ester bond, or a thioester bond. In the case of a carboxyl group, a salt may be formed even in a form in which a hydrogen atom is bonded. As the counter ion of the carboxyl group, alkali metal salts, ammonium salts,
Amine salts and the like.

The polyamino acids used in the present invention are crosslinked. The bonding portion between the basic skeleton and the crosslinked portion of the present invention is not particularly limited. For acidic polyamino acids, an amide bond,
An ester bond and a thioester bond. These crosslinking portions and side chain portions may be unsubstituted or substituted.

Examples of the substituent include an alkyl group having 1 to 18 carbon atoms which may be branched or unbranched, a cycloalkyl group having 3 to 8 carbon atoms, an aralkyl group and a phenyl group which may be substituted. , A naphthyl group which may or may not be substituted, an alkoxy group which may have 1 to 18 carbon atoms and may be branched, an aralkyloxy group, a phenylthio group, which may have 1 to 18 carbon atoms An alkylthio group, an alkylamino group having 1 to 18 carbon atoms which may or may not be branched, a dialkylamino group having 1 to 18 carbon atoms which may or may not be branched,
Trialkylammonium group having 1 to 18 carbon atoms which may or may not be branched, hydroxyl group, amino group, mercapto group, sulfonyl group, sulfonic acid group, phosphonic acid group and salts thereof, alkoxycarbonyl group, alkyl And a carbonyloxy group.

The basic skeleton, cross-linked portions, and side chain portions of these polyamino acid resins are not particularly limited. Any resin can be used irrespective of the production method, as long as it can exhibit sufficient water-absorbing ability as the water-absorbing resin contained in the absorbent core.

As the crosslinked polyaspartic acid, resins produced by various methods can be used regardless of the production method. For example, a method of partially crosslinking polysuccinimide with a polyvalent amine and hydrolyzing the remaining imide ring with an alkali or the like, mixing aspartic acid, polyaspartic acid and lysine, and crosslinking while polymerizing, Examples thereof include a method of mixing polyaspartic acid and a polyamine and dehydrating and condensing at a high temperature, a method of reacting polyaspartic acid with a polyvalent glycidyl compound, and a method of irradiating an aqueous solution of polyaspartic acid with γ-rays. Any of the resins produced by these methods can be used irrespective of the production method, as long as the resin can exhibit sufficient water-absorbing ability as a water-absorbing resin contained in the absorbent core.

Further, another water-absorbing resin having biodegradability may be used in combination. If necessary, a water-absorbing resin having no biodegradability may be used in combination as long as the biodegradability of the absorbent article is not impaired.

(8) Support component (B component) of the water-disintegrable superabsorbent composite The support component (B component) is a tissue-like mat made of wood pulp fibers, and wood pulp fibers as main components. And a mixture sheet of fibers having a fiber length of 25 mm or less, rayon having a fiber length of 25 mm or less,
Cotton, and those composed of cellulose fiber selected from the group consisting of lyocell as a main component and containing a binder composed of polyvinyl alcohol or a partially crosslinked product thereof, and rayon, cotton and lyocell having a fiber length of 25 mm or less. Examples include those composed mainly of cellulose fibers selected from the group and containing a binder composed of an alkaline earth metal salt of carboxymethyl cellulose.

(9) Binding component (component C) of the water-disintegrable superabsorbent composite In the composite according to the present invention, the microfibrillar cellulose is firstly stable against moisture,
Second, it functions as a binder that does not impair the absorbency of the water-absorbent resin, and achieves a secondary structure mainly composed of the water-absorbent resin.

In the present invention, the network structure for restraining the water-absorbent resin at a predetermined position is constituted by so-called microfibrillar cellulose. This microfibrillar cellulose generally has an average diameter of 2.0 μm to 0.01 μm and an average length of 0.01 μm to
It is a very thin fibrous material of 0.1 μm and has water resistance that can prevent the structure from being immediately collapsed by swelling when the water-absorbent resin absorbs water. And has such a property that the swellability of the water-absorbent resin is not impaired.

It should be noted that the microfibrillar cellulose has an extremely strong hydration property that binds to water as a solvation (bound water). When dispersed in water, it hydrates, shows large viscosity, and shows a property of stably maintaining a dispersed state. In the present invention, the term "microfibrillar cellulose" is used as a general term for fibrous materials having strong hydration properties, and in some cases, those having an average diameter exceeding 2.0 μm are also used. It is possible, and a mixture of so-called microfibrillar cellulose and microfibrillar cellulose may be used.

FIG. 5 is an example showing the relationship between the concentration of microfibrillar cellulose (S-MFC) in the dispersion and its viscosity. From FIG. 5, it can be seen that the composition has high viscosity characteristics even at a low concentration. Further, the dispersion liquid of the microfibrillar cellulose exhibits a structural viscosity, shows a flow orientation by applying a shear, and lowers the viscosity, but recovers as the shear decreases. Therefore, when the particulate water-absorbing resin is added and dispersed in the dispersion medium of the microfibrillar cellulose, the water-absorbent resin is stably incorporated into the network structure of the microfibrillar cellulose in a low-share dispersion state, and It is possible to stably disperse the water-absorbing resin in a concentration. Also, when transported by a pump or the like, the viscosity is reduced and transport becomes easier.
When the dispersion medium is removed and the dried state is reached, the microfibrillar celluloses are self-joined to form a plaster, whereby the crosslinked polyamino acid particles can be stably bonded and fixed.

Therefore, when the water-absorbing resin is dispersed in the microfibrillar cellulose dispersion medium, the high-concentration water-absorbing resin can be stably dispersed. In the process of removing the dispersion medium, the self-bonding is firmly performed. It becomes a plaster, forms a network structure, wraps the water-absorbent resin and mechanically surrounds it, and at the same time, the microfibrillar celluloses are bonded by the ionic hydrogen bonding effect, ensuring the crosslinked polyamino acid particles Hold.

The microfibrillated cellulose used in the present invention can be obtained by subjecting cellulose or a cellulose derivative to microfibrillation.
For example, the wood pulp can be obtained by grinding and highly beating through a process as shown in FIG. The microfibrillated cellulose is called MFC (microfibrillated cellulose), and the one with more advanced microfibrillation is called S-MFC (super microfibrillated cellulose).

Alternatively, microfibrillar cellulose can be obtained by metabolism of microorganisms. Generally, acetic acid bacterium Xilinam (Acetobacter Xy)
linum), etc., by stirring and culturing in a medium containing a suitable carbon source to produce crude microfibrillar cellulose, followed by purification. This microfibrillated cellulose is called BC (bacterial cellulose).

Further, a so-called fibril-like substance obtained by coagulating a copper ammonia solution, an amine oxide solution, an aqueous cellulose xanthate solution, or an acetone solution of diacetylcellulose having spinnability, under shearing stress, is further disintegrated. It is also possible to use microfibrillar substances obtained by the above.

Microfibrillar cellulose (a-2)
Is preferably cellulose or a cellulose derivative, more preferably one obtained by grinding and / or beating pulp, or one obtained by microbial metabolism.

The details of these microfibrillar celluloses are described in JP-B-48-6641, JP-B-50-38720 and the like, and the product name "Celcream" (manufactured by Asahi Kasei Corporation) and commercial products It is commercially available under the name “Selish” (manufactured by Daicel Chemical Industries, Ltd.) and the like.
% Of S-MFC and BC.

(10) Additional structure of the water-disintegrable superabsorbent composite The composite of the present invention can have not only a single structure but also a multiple structure. In particular, the absorption capacity can be enhanced by adopting a structure in which absorbent components are stacked or by giving a concentration gradient of the water absorbent resin.

The location of the absorbing component is not particularly limited.
The structure may be any of the upper layer, the middle layer, and the lower layer as long as the structure can efficiently absorb body fluid and the like. The state of the distribution is not particularly limited, and it is preferable that the distribution be efficient according to the amount of the target liquid and the injection portion. In order to increase the efficiency, the distribution of the complex can be unevenly distributed in advance. Further, the water-absorbing resin can be dispersed and distributed so that its performance can be sufficiently exhibited.

To make water diffusion more efficient, absorbent paper and diffusion paper can be used. The absorption paper and the diffusion paper are also not limited, but usually a paper mainly composed of cellulose is preferred. Further, it may be mixed with pulp in order to make diffusion more efficient.

The water-disintegrable superabsorbent composite of the present invention may contain, if necessary, salt,
Inorganic compounds such as colloidal silica, white carbon, ultrafine silica, and titanium oxide powder, organic compounds such as chelating agents, oxidizing agents, antioxidants, reducing agents, ultraviolet absorbers, antibacterial agents, bactericides, and fungicides , Fertilizers, fragrances, deodorants, pigments and the like may be added. The location where these additives are contained may be either the absorber layer or the support layer. If necessary, a material having a deodorizing and deodorizing function may be contained. Further, an antibacterial material for suppressing the propagation of bacteria can be contained.

Further, a method of applying a hydrophobic compound such as a silicone-based oil or paraffin wax to the periphery or a method of applying a hydrophilic compound such as an alkyl phosphate ester in advance to prevent leakage due to bleeding of urine or the like at the periphery. You can prevent it.

(11) Method for producing water-disintegrable superabsorbent composite The method for producing the water-disintegratable superabsorbent composite of the present invention is not particularly limited, but a preferred method is exemplified. The following describes two methods.

(11-1) A method of casting a suspension containing a water-absorbent resin, microfibrillar cellulose, and water and / or a water-miscible organic solvent on a support layer, and drying the suspension. Water-miscible, capable of suppressing swelling of the water-absorbent resin and hydrating and dispersing hydratable microfibrillar cellulose obtained from microfibrillar cellulose or cellulose derivative (hereinafter referred to as microfibrillar cellulose). The water-absorbent resin and the microfibrillar cellulose are dispersed in a dispersion medium comprising a mixed solvent of a certain organic solvent and water, and the water-absorbent resin and the microfibrillar cellulose are mixed with the mixed solvent from the obtained dispersion. And then drying after removing the solvent.

In the present production method, a suspension containing microfibrillated cellulose and water and / or a water-miscible organic solvent is coated with a water-absorbent resin when dried and the solvent is removed. Call it a binder.

In the present invention, the dispersion behavior of the water-absorbent resin in the dispersion medium of the microfibrillar cellulose and the dispersion of the microfibrillar cellulose after the solvent removal in the production of the water-disintegrable superabsorbent composite as described above are described. Uses the behavior cleverly. That is, the water-absorbent resin of the present invention, the microfibrillar cellulose is hydrated and dispersed stably, in a dispersion medium comprising a mixed solvent of water-miscible organic solvent and water, the water-absorbent resin and the microfibril-like cellulose It can be obtained by dispersing cellulose, separating the water-absorbent resin and the microfibrillated cellulose from the mixed solvent from the obtained dispersion, removing the solvent, and then drying. As a result, a typical water-disintegrable superabsorbent composite of a typical pulp having a water-absorbent resin content of 90% or more can be obtained.

First, in order to prepare a dispersion of microfibrillar cellulose, a dispersion of microfibrillar cellulose having a relatively high concentration is prepared and used as a mother liquor. As the mother liquor, the higher the concentration, the more compact the manufacturing apparatus, but the higher the viscosity, the more difficult it becomes to handle, so that it is 10% or less, preferably 1% to 5%.
Is used. This microfibrillar cellulose mother liquor is added to a mixed solvent of an organic solvent and water to prepare a microfibrillar cellulose dispersion having a predetermined microfibrillar cellulose concentration and a viscosity associated therewith. As a means for mixing and adding a water-absorbing resin, a method of dispersing a granular water-absorbing resin in the above-described microfibrillar cellulose dispersion is generally used.

The organic solvent used in the present invention can be used as long as it is compatible with water and does not greatly swell the water-absorbing resin. Examples thereof include methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, and the like. Propylene glycol, dioxane, acetone,
Examples include tetrahydrofuran, glycerin, neopentyl glycol, pentaerythritol, dimethyl sulfoxide and the like.

Among them, those which are easy to volatilize during drying and have high safety are preferable. For example, C 1-6
Preferred are alcohols, glycols, ethers and ketones.

By dispersing the microfibrillar cellulose and the water-absorbent resin in the mixed solvent comprising the organic solvent and water, a network structure of the microfibrillar cellulose is formed, the water-absorbent resin is incorporated, and a stable dispersion state is ensured. After that, when the mixed solvent is removed, a three-dimensional structure is formed due to the physical entangled structure of the microfibrillar cellulose and the formation of stable hydrogen bonds between the microfibrillar celluloses. It is presumed that.

The mixing ratio of the organic solvent and water is set within a range that enables the formation of a network structure of the microfibrillar cellulose and suppresses the water absorption of the water-absorbing resin as much as possible. The results of measuring the relationship between the concentration of each organic solvent and the water absorption ratio of the water absorbent resin when methyl alcohol, ethyl alcohol and acetone were used as the organic solvent are shown in the graph of FIG. FIG. 7 shows that in the case of ethyl alcohol and acetone, the water absorption ratio of the water-absorbent resin sharply increases when the concentration becomes 50% or less. In the case of methyl alcohol, the water absorption ratio in the water-absorbent resin rises sharply at 60% or less. On the other hand, in order to hydrate and stably disperse the microfibrillated cellulose, it is advantageous that the content of water in the mixed solvent is large. Therefore, the mixing ratio of the organic solvent / water is suitably in the range of 40/60 to 90/10. This ratio slightly varies depending on the organic solvent used and the properties of the water-absorbing resin used. In some cases, a three-component solvent system may be employed to widen the stable region. For example, a three-solvent system of PGA / ethanol / water.

In the mixed solvent, the dispersion ratio of the water-absorbent resin and the microfibrillar cellulose and the concentration ratio of the water-absorbent resin and the microfibrillar cellulose in the co-dispersed state of the water-absorbent resin and the microfibrillar cellulose. This will be described in more detail. The concentration of the water absorbent resin is
Although it depends on the transport method of the system, it is selected from the range of 60% or less, preferably 5% to 50%, from the viewpoint of easy handling. The microfibrillated cellulose concentration is affected by the bonding strength and dispersion stability of the water-absorbent resin. To maintain good dispersion stability, 0.2% or more is required, and preferably 0.3% to 1.0%.

The mixed solvent containing the microfibrillar cellulose at such a concentration shows good dispersion stability as described above, and hardly causes phase separation even after being left for a long time. According to the results of the experiment, the dispersion stability was improved as the concentration of the microfibrillar cellulose was increased. At 0.3%, no phase separation occurred until 1 hour, and at 0.5%, even after 65 hours. No phase separation was observed. This good dispersion stability not only facilitates the operation at the time of coating, but also demonstrates that the microfibrillar cellulose can uniformly surround the water-absorbent resin and stably disperse. It is presumed that it forms the basis of excellent water absorption of the composite of the present invention.

Ratio of microfibrillated cellulose to water absorbent resin (MFC / water absorbent resin × 100 (%))
When the value is large, the strength increases, but it becomes paper-like and becomes hard. 0.3%
Below, it is difficult to obtain a sufficient bonding force. The evaluation of the bonding force can be performed with the aid of the cellophane tape method used for measuring the surface strength. From the results, a more preferable range is 0.5% to 5%.

The possibility of adding other components to the water-absorbent resin and the microfibrillar cellulose coexisting dispersion system will be described. In the present invention, one of the important points is how to handle the water-absorbent resin at a high concentration. Considering the binding efficiency between the microfibrillar cellulose and the water-absorbent resin, a two-component system of the water-absorbent resin and the microfibrillar cellulose is desirable, but the addition of CMC or the like as a thickener to further enhance the viscosity stability of the system. In some cases, it is necessary to add polyethylene glycol or glycerin as a plasticizer in order to prevent hardening due to overdrying. It is also possible to add a wood pulp slurry or a synthetic fiber dispersion slurry to the above-mentioned dispersion system, but these additions hinder the stability of the dispersion and cause the binding between the microfibrillar cellulose and the water absorbent resin. Efficiency is also reduced and should be kept to a minimum.

Next, a method for forming a composite from a dispersion in which microfibrillated cellulose and a water-absorbent resin are dispersed in a mixed solvent will be described with reference to the drawings. As a method of forming a composite from the so-called slurry-like dispersion liquid, for example, as shown in the process of FIG. 8, a block-like substance obtained by separating a solvent from a slurry is dried and pulverized into particles. A spherical particle as shown in FIG. 9 (a) or a flake-like particle as shown in FIG. 9 (b), in which the particle surface of the water-absorbent resin is coated with microfibrillar cellulose, is obtained. If the slurry is poured into a mold made of a net and solid-liquid separated and then dried, a shape-shaped composite having a three-dimensional structure such as a pellet, a rod, a tube, a corrugated plate, etc. is obtained according to the mold used. If a thin film is continuously formed and dried, a sheet-like composite can be obtained. Since the composite thus obtained becomes flexible due to water content, for example, a sheet-like composite is formed into a mat shape with fibers by an airlaid method, and moisture is given to this. By pressing and drying, it is possible to re-form into a sheet.

Hereinafter, a method of directly forming a sheet from a dispersion liquid, which is particularly versatile, will be described in detail. The network structure of the microfibrillar cellulose as described above enables the formation of an extremely thin layer while maintaining a state in which the water-absorbent resin is stably and firmly held inside. That is, a dispersion obtained by dispersing the microfibrillar cellulose and the water-absorbent resin in a dispersion medium is cast on an appropriate plane, and a sheet-like water-disintegrable high water-absorbency composed of only the microfibrillar cellulose and the water-absorbent resin A complex can be formed. The water-disintegrable superabsorbent composite layer 10 of this embodiment is shown in FIG. FIG.
In (a), reference numeral 11 denotes a microfibrillar cellulose, and 12 denotes a water-absorbing resin. Actually, FIG. 10 (b) sketched from a 70 × micrograph.
As shown in the figure, each water-absorbent resin is completely wrapped by the microfibrillar cellulose, and entangled with the adjacent water-absorbent resin by the microfibrillar cellulose. Has been taken into.

The dispersion is cast on a suitable sheet-like support.
When the dispersion is dried, the sheet
Water-disintegrable superabsorbent composite consisting of a fragile superabsorbent composite layer
The body is obtained. In particular, porous non-woven sheets can be used as sheet supports.
If a woven fabric is used, the dispersion may vary depending on the porosity.
Of the dispersion enters the space between the fibers of the nonwoven fabric,
After drying, sketch from FIG.
As shown in FIG. 11B, the sheet-like support 13 and water
The disintegrable superabsorbent composite layer 10 is entangled with the joint surface between the two.
It becomes a complex with a different structure. Preferred porosity of this nonwoven
The degree is expressed as an apparent density of 0.2 g / cm.^ThreeBelow and further
Preferably 0.01 to 0.1 g / cm^ThreeIt is. In addition,
In this case, the constituent materials of the nonwoven fabric include liquid permeability, water
Cotton, rayon, wood pulp, etc. due to the problem of disintegration
Hydrophilic material, relatively short fibrous material with hydrophilic treatment
Can also be used. Especially microfibrillar cellulos
If the source is S-MFC or BC,
In addition, because of its extremely strong hydrogen bonding, cellulose-based
When a material is used, it is more strongly and stably bonded when dried. Ma
It also shows very good permeability when wet. (11-2) Spraying the water-absorbing resin on the support layer,
Microfibrillated cellulose and water and / or water
Casting a suspension comprising a miscible organic solvent and drying
In the present production method, microfibrillar cellulose, and
And a suspension comprising water and / or a water-miscible organic solvent
Dry and remove solvent to coat and bind water absorbent resin
Therefore, it is called a coated binder. Spraying method of water absorbent resin
Slide with vibrator, screw type
Spraying with a leader or grid roll, or electrostatic coating
And a method using static electricity such as a device. C
Part of the water-absorbing resin sprayed on the support
Is fixed by being entangled with the mesh of the support fabric
The conductive resin is not fixed. Even in this state is final
Is fixed by the covering binder so that there is no problem. Only
During production, it is better to fix the water-absorbent resin
Less loss due to spill and offset of water absorbent resin due to misalignment
Not more desirable. Specifically, temporary fixing of water-absorbent resin
As a method, for example, the sheet-like support of the first layer is
The property of fixing the movement of the resin powder between the aqueous resin powders
This is achieved by applying a binder having the same. Toes
For example, as the water-absorbent resin adheres to the sheet-like support,
A small amount of water on the sheet support
The water-absorbent resin can be temporarily fixed to the sheet-like support.
The binder used in the present invention uses a water-absorbing resin instead of water.
Non-swelling ethylene glycol, propylene, glyco
Alcohol or an aqueous solution thereof.
it can. Also, to increase the fixing strength of the water-absorbent resin,
Clofibril cellulose coated binder dispersion
Can also be. Also, carboxymethyl cellulose
Water, carrageenan, hydroxyalkyl cellulose,
Sodium alginate, polyvinylpyrrolidone, polyethylene
Adhesion of lenoxide, sodium polyacrylate, etc.
Aqueous solution or polyvinyl acetate emulsion
Applying an emulsion adhesive will seal the water-absorbent resin.
It can be firmly fixed to the support. However,
The above adhesives may impair water permeability, so use
The dose is naturally restricted, and is 2.0 g /
m ^TwoIt is desirable that: Or the adhesive water soluble
The liquid contains microfibrillar cellulose, bacterial cellulos
If used in a blended state, water absorption will be maintained without impairing water permeability.
The fixing strength of the aqueous resin can be further increased. Coating
The mixture has water permeability, and furthermore, the sheet-like support
Movement of water-absorbing resin even when bent or expanded
Is used to secure firmly so that no
It is.

That is, the coated binder containing microfibrillar cellulose as a main component used in the present production method, in addition to the physical entanglement of the microfibrillar cellulose,
Since they are bound by extremely strong hydrogen bonds, a network structure of microfibrillar cellulose is formed. In other words, this network structure does not cover almost the entire surface of each water-absorbent resin with the microfibrillar cellulose, but as shown in FIG. 23, the microfibrillar cellulose covers the upper surface of the water-absorbent resin. By such application, the microfibrillar cellulose layer is formed, and the water-absorbent resin group can be fixed to the sheet-like support. In addition, when dried, the extremely thin network structure weakens, and has extremely good water permeability without inhibiting swelling of the water-absorbent resin. Examples of the method for forming the coating tie layer include a method of spraying a dispersion of microfibrillar cellulose on the upper surface of the water-absorbent resin, or a method of curtain coating. At the same time, using a decompression device, spraying or coating the dispersion while suctioning the sheet-like support surface different from the water-absorbent resin spray surface, the dispersion does not stop at the water-absorbent resin surface but also between the water-absorbent resin and the sheet-like support It is dispersed, and the fixation of the water-absorbent resin to the sheet-like support becomes strong.

After coating the above coated binder,
By removing the solvent used for the temporary fixation, water or the organic solvent used as the dispersion liquid of the microfibrillated cellulose by a method such as drying, a typical sheet containing 70% by weight or more of the water-absorbing resin in the sheet. A pulp press superabsorbent sheet can be obtained. (Water absorbent resin / (Water absorbent resin +
Coating binder) is at least 90% by weight. Especially when water is used, although the amount of water is small, it is necessary to remove water as quickly as possible because the water-absorbing resin swells.
It is desirable to dry within 5 minutes.

After coating with the coated binder,
There is no problem if the sheet-like support is laminated on the surface of the coating bonding layer and dried.

When the coated binder is sprayed near the position where the water-absorbent resin is sprayed, the formation of the layer between the water-absorbent resin and the coated binder cannot be clearly distinguished, and each of the layers has a concentration gradient. However, such a layer may be formed without any problem.

The superabsorbent sheet of the present invention may be a sheet having a binding layer coated with a water-absorbing resin on the entire surface, or a striped or island-shaped pattern. What is necessary is just to select a shape according to a use form. In particular, according to the method of the present invention, a conventional method, for example, Japanese Patent Application Laid-Open No. 11-034200 (Japanese Patent Application No. 9-1).
No. 92159), it is extremely easy to form a pattern.

The superabsorbent sheet in which the water-absorbent resin is formed in a stripe shape is, for example, as shown in FIG. 24, a solution for temporarily fixing the water-absorbent resin is formed in a stripe shape on the upper surface of a moving sheet-like support. After application, it can be manufactured by spraying a large number of spraying ports from a water-absorbing resin spraying device arranged at right angles to the moving direction of the sheet. The island-shaped superabsorbent sheet is manufactured by applying a solution for temporarily fixing the water-absorbent resin in an island shape, and then intermittently spraying the water-absorbent resin with the above-described spraying device and then the coating binder. be able to.

The possibility of adding other components to the water-absorbent resin and the microfibrillar cellulose coexisting dispersion system will be described. In the present invention, one of the important points is how to handle the water-absorbent resin at a high concentration. Considering the binding efficiency between the microfibrillar cellulose and the water-absorbent resin, a two-component system of the water-absorbent resin and the microfibrillar cellulose is desirable, but CMC such as CMC as a thickener for further increasing the viscosity stability of the system is preferred. Addition,
In some cases, it is necessary to add polyethylene glycol or glycerin as a plasticizer to prevent curing due to overdrying. It is also possible to add a wood pulp slurry or a synthetic fiber dispersion slurry to the above dispersion system, but these additions hinder the stability of the dispersion and increase the binding efficiency of the microfibrillar cellulose to the water absorbing resin. Should be kept to the minimum necessary.

Next, a method for forming a composite composition from a dispersion in which microfibrillar cellulose is dispersed in a mixed solvent will be described with reference to the drawings. As a method of forming a water-disintegrable superabsorbent composite from the above-mentioned slurry-like dispersion, for example, as shown in the process of FIG. 8, a block-like substance obtained by separating a solvent from a slurry is dried, and then pulverized. 9A, the surface of the water-absorbent resin is coated with the microfibrillar cellulose, and the spherical particles as shown in FIG. 9A or the flake particles as shown in FIG. The obtained slurry is poured into a mold made of, for example, a net, solid-liquid separated, and then dried. Then, depending on the mold used, a shape-forming composite having a three-dimensional structure such as a pellet, a rod, a tube, or a corrugated plate is formed. A body is obtained, and a sheet-like composite is obtained by continuously forming a thin film and drying. Since the composite composition thus obtained becomes flexible due to moisture content, a sheet-like composite is molded into a mat shape together with fibers by, for example, an airlaid method,
It is also possible to reshape it into a sheet by giving it moisture and pressing and drying.

Hereinafter, a method of directly forming a sheet from a dispersion liquid, which is particularly versatile, will be described in detail. The network structure of the microfibrillar cellulose as described above enables the formation of an extremely thin layer while maintaining a state in which the water-absorbent resin is stably and firmly held inside. That is, a dispersion in which microfibrillar cellulose is dispersed in a dispersion medium is cast to form a sheet-like water-disintegrable superabsorbent composite composed of only microfibrillar cellulose and a water absorbent resin. The water-disintegrable superabsorbent composite layer 10 of this embodiment is shown in FIG.
Shown in In FIG. 10A, reference numeral 11 denotes microfibrillar cellulose, and 12 denotes a water-absorbing resin. Actually, as shown in FIG. 10 (b) sketched from a 70 × photomicrograph, each water-absorbent resin particle is completely wrapped by fine microfibrillar cellulose, and the adjacent water-absorbent resin particles It is incorporated into the microfibrillar cellulose network structure entangled with the particles by the microfibrillar cellulose.

When the dispersion is cast on a suitable sheet-like support, after the dispersion is dried, a water-disintegrable superabsorbent composite comprising the sheet-like support and the water-disintegrable superabsorbent composite layer is formed. A complex is obtained. In particular, when a porous non-woven fabric is used as the sheet-like support, a part of the dispersion enters the space between the fibers of the non-woven fabric according to the degree of porosity, and after the dispersion is dried, FIG. As shown in FIG. 11B sketched from a micrograph, the sheet-shaped support 13 and the water-disintegrable superabsorbent composite layer 10 become a composite having a structure in which they are entangled at the joint surface between them. Preferably the porous Shitsudo nonwoven in this case, when indicated by apparent specific gravity of 0.2 g / cm ³ or less, more preferably from 0.01 to 0.1 g / cm ^3. In addition, as a constituent material of the nonwoven fabric in this case, a hydrophilic material such as cotton, rayon, and wood pulp, or polyethylene, polypropylene,
It is desirable to use a material obtained by subjecting a synthetic fiber such as polyester to a hydrophilic treatment. In particular, when the microfibrillated cellulose is S-MFC or BC, in addition to physical confounding, the hydrogen bonding property is extremely strong. Therefore, when a cellulose-based substrate is used, the cellulose-based base material is more stably bonded when dried. It also shows very good permeability when wet. As the shape of the non-woven fabric used as the support, in addition to non-woven fabrics such as porous card dry type and spun bond, sheet-like materials such as surface brushed non-woven fabric, weakly carded card web, or opened tow can be used. is there.

Further, as shown in FIG. 12, in the structure shown in FIG. 11, another sheet material is joined to the sheet-like support 13 so as to be in contact with the water-disintegrable superabsorbent composite layer 10. You can also. If a liquid-impermeable sheet material is used as this other sheet material, the composite of FIG. 12 alone can also have the function of an absorbent product consisting of a top sheet, an absorber and a back sheet. .

Further, in the structure shown in FIG. 11, a water-disintegrable superabsorbent composite layer can be provided over the entire surface of the sheet-like support, but it can also be provided partially in a desired pattern. For example, as shown in FIG. 13, a plurality of water-disintegrable superabsorbent composite layers 10 are provided at predetermined intervals only in one surface of a sheet-like support 14 in the form of a belt having a predetermined width, and adjacent water A zigzag cross section can be obtained by folding between the disintegrable superabsorbent composite layers 10 in a mountain fold and a valley fold. Since the composite sheet having such a configuration has a larger volume of the water-disintegrable superabsorbent composite layer 10 existing per unit area than a flat composite sheet, the composite sheet exerts a larger absorption capacity. Alternatively, as shown in FIG. 14, when the zigzag mountain is greatly inclined in one direction, the volume of the water-disintegrable superabsorbent composite layer 10 existing per unit area can be further increased. Further, as shown in FIG. 15, ridges inclined in opposite directions can be provided on both sides of the flat central portion.

Further, such a zigzag structure also provides a free and sufficient space for easily swelling by absorption when the water absorbent resin is used as an absorbent product.

FIG. 16 is a partial perspective view showing an example of the water-disintegrable superabsorbent composite formed according to the present invention. In this water-disintegratable superabsorbent composite, a water-disintegratable superabsorbent composite layer 10 is arranged on one surface of a sheet-like support 13 made of an elastic body in a belt shape extending in parallel with each other at a predetermined interval. Then, a wave-shaped liquid-permeable nonwoven fabric 14 is arranged thereon,
Each of the valleys of the liquid-impermeable nonwoven fabric 14 has a structure in which the liquid-impermeable nonwoven fabric 14 and the sheet-like support 13 are joined at the joining portion 5. Is accommodated in a channel 16 formed between the sheet-like support 13 and the liquid-impermeable nonwoven fabric 14.

The water-disintegrable superabsorbent composite having such a structure is used in an absorbent product such as a sanitary napkin or diaper, for example, in a direction perpendicular to the length direction of the water-disintegratable superabsorbent composite layer 10. It can be advantageously used as a composite having high elasticity and excellent water absorption. In this case, the liquid-impermeable non-woven fabric 14 is used as the side in contact with the body, and the liquid is first applied to the liquid-impermeable non-woven fabric 1.
4 and is absorbed by the water-disintegrable superabsorbent composite layer 10. As the water absorption increases, the volume of the water-disintegrable superabsorbent composite layer 10 expands, which is located in a channel 16 formed between the sheet-like support 13 and the liquid-impermeable nonwoven fabric 14. So
Free inflation is allowed.

FIG. 17 shows an application example of the water-disintegrable superabsorbent composite of the present invention. In FIG. 17, the liquid-impermeable sheet denoted by reference numeral 21 does not allow liquid to permeate, and has an appropriate flexibility. The liquid-impermeable sheet 21 is superimposed with the superabsorbent composite sheet material 22. I have. These two parts are connected to each other at a number of connecting parts 23 extending in a linear or band shape parallel to each other and arranged at a predetermined interval. The connecting portion 23 is formed of the liquid impermeable sheet 2.
1 and the superabsorbent composite sheet material 22 are formed by heat-sealing with a predetermined width by ordinary means, for example, heat sealing, high-frequency bonding, or the like.

The length of the highly water-absorbent composite sheet material 22 between two adjacent connecting portions 23, 23 is longer than the length of the liquid impermeable sheet 21, and therefore, between each connecting portion 23, 23, A channel 24 is formed between the superabsorbent composite sheet material 22 and the liquid impermeable sheet 21 due to the slackness of the superabsorbent composite sheet material 22.

The superabsorbent composite sheet material 22 is manufactured by P.I. P.
Or P. E. FIG. The structure shown in FIG. 11 obtained by supporting a water-disintegrable superabsorbent composite layer 10 on one surface of a sheet-like support 13 such as a polyolefin spun bond or a dry nonwoven fabric, The water-disintegrable superabsorbent composite layer 10 is placed on the side facing the liquid impermeable sheet 21.

The sheet-like product having such a structure is
Even when a large amount of liquid is absorbed, it is extremely excellent in self-retaining property for maintaining a sheet-like shape stably. Next, an apparatus suitable for producing the water-disintegrable superabsorbent composite of the present invention will be described with reference to the drawings.

In FIG. 18, reference numeral 31 denotes a tank for storing ion-exchanged water, 32 denotes a tank for storing microfibrillated cellulose mother liquor, 33 denotes a tank for storing acetone, and 34 denotes a tank for storing SAP.
The microfibrillated cellulose aqueous dispersion mother liquor taken out of the tank 32 is introduced into a mixer 35 provided with a stirrer, and is diluted in the mixer 35 with the water taken out of the tank 31. It is then introduced into a mixer 36 equipped with a stirrer. This mixer 36 has a tank 3
Acetone taken out of 3 is introduced, and this mixture is, by the action of a pump, mixed with the next mixer 3 equipped with a stirrer.
7 is introduced. Granular SAP is introduced into the mixer 37 from the tank 34, where a mixed dispersion of microfibrillar cellulose, an organic solvent, water and SAP is formed.

On the other hand, after a suitable sheet-like support 13 such as a non-woven fabric is unwound from a roll 38,
It is led to 0. The forming section 40 includes a belt conveyor 41.
And the nozzle 4 located on the belt of this belt conveyor
The mixed solvent is supplied to the nozzle 42 from the mixer 37 by the action of a pump.
While the sheet-like support 13 is guided by the belt conveyor 41 and travels at a predetermined speed, the mixed dispersion from the nozzle 42 is applied to the surface thereof. The nozzle 42 has an appropriate shape according to the pattern of the water-disintegrable superabsorbent composite layer to be provided on the sheet-like support 13.

The forming section 40 is further provided with a roll press 43 comprising a pair of rollers, and by pressing the sheet-like support 13 coated with the mixed solvent,
The solvent contained in the mixed solvent is squeezed, and the separated solvent is returned to the mixer 36 by the action of a pump.

After leaving the forming section 40, the sheet-like support 13 is sent to the next drying section 50. Hot air is supplied to the drying unit 50 and a pair of porous rolls 51 and 52 are provided.
The sheet-like support 13 and the mixed solvent applied thereto are dried while being conveyed along the peripheral surfaces of the porous rolls 51 and 21.

After leaving the drying section 50, the product is compressed by a compression section 60 composed of a pair of press rolls 61 and 62, and is provided with a water-disintegrable superabsorbent composite layer on the sheet-like support 13. Is obtained. FIG. 19 shows a combination of the step shown in FIG. 18 with the step of producing microfibrillar cellulose from acetyl cellulose. In this step, the acetate dope is contained in the tank 31a, the coagulation liquid is contained in the tank 32a, and the acetone is contained in the tank 33a. The acetate dope and the coagulation liquid taken out of the tanks 31a and 32a are supplied to a suitable fibrillating device such as an aspirator. 39, where fibrillation takes place. The fibrils are opened in a mixer 35a, turned into finer microfibrils and slurried, mixed with acetone from a tank 33a in a mixer 36a, and then in a next tank (not shown). Mixed with SAP. The following steps are the same as the steps shown in FIG.

Referring again to FIG. 18, an example of another apparatus for applying the mixed dispersion to the sheet-like support 13 in the forming section 40 is shown in FIG. In FIG. 20, reference numeral 44 denotes
A tank with an open top for containing the mixed dispersion is shown.
Inside, with a part of the peripheral surface immersed in the mixed dispersion,
An immersion roll 45 rotatable about a horizontal axis is provided. Further, a pair of rolls 46 and 47 are provided rotatably about an axis parallel to the immersion roll 45, respectively. One roll 46 is a dipping roll 45
21 and has a large number of ring-shaped grooves 46a on the peripheral surface, for example, as shown in FIG. 21, in the nip between the other roll 47 having a flat surface, The sheet-like support 13 to which the mixed dispersion is to be applied passes.

The mixed dispersion contained in the tank 44 is
It adheres with its own viscosity to the peripheral surface of the immersion roll 45 moving in it, and is then transferred to the sheet-like support 13 via the grooved roll 46. Therefore, the sheet-like support 13
As shown in FIG. 22, a mixed dispersion layer 48 is formed in a number of bands parallel to each other, as shown in FIG. The pattern of the concavities and convexities formed on the roll 46 can be set arbitrarily, and the mixed dispersion can be applied to the sheet-like support 13 in a pattern corresponding to this pattern.

(12) Effect of water-disintegrable superabsorbent composite The features and performance of an absorbent product incorporating the composite obtained in the present invention will also be described briefly.

First, both before and during use, in a non-water-absorbing state, it has an extremely thin and compact structure, and the water-absorbing resin is firmly fixed and stabilized. The water absorbent resin does not move,
It is difficult for the water-absorbent resin to fall off and for the structure to break down.

Second, at the time of water absorption, the absorption rate is high and no blocking occurs due to the hydrophilicity of the microfibrillated cellulose and its physical form despite the pulp structure of the water-absorbing resin of 90% or more.

Third, even after water absorption, the swollen polymer is gently grasped by the fibril network to prevent the polymer from falling off.

Fourth, there is a characteristic at the time of disposal after use. The absorbent of the present invention is stable in a stationary state when exposed to excess water, but has the property of disintegrating immediately upon application of shear, and is therefore suitable for flashable product design. Further, microfibrillar cellulose has extremely high cellulase activity, and its structure varies in a short period of time when buried in soil.

[0212]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples. In the following Examples and Comparative Examples, “parts” means “parts by weight”.

In the present invention, (1) the measurement of the water absorption capacity of the resin,
(2) Measurement of water absorption capacity of water-disintegrable superabsorbent composite, (3)
Measurement of disposal of the water-disintegrable superabsorbent complex in flush toilets,
It was performed about.

(1) Measurement of Water Absorption Capacity of Resin The water absorption capacity of the resin in the examples was measured for physiological saline and the equilibrium swelling water absorption.

[0215] The equilibrium swelling and water absorption of the resin was measured using the tea bag method. That is, about 0.1 part of the resin is placed in a non-woven tea bag (80 mm × 50 mm) and immersed in an excess of the corresponding solution to swell the resin for one hour.
After the tea bag was pulled out and drained for 1 minute, excess water was absorbed by a large amount of tissue paper, and the weight of the tea bag containing the swollen resin was measured. When the same operation was performed using only the tea bag as a blank, the value obtained by dividing the value obtained by subtracting the weight of the blank and the resin from the weight of the tea bag containing the swollen resin by the weight of the resin was taken as the water absorption (g). / Resin 1 g). The physiological saline is a 0.9% by weight aqueous sodium chloride solution.

(2) Measurement of Water Absorbing Ability of Water-Disintegrating Superabsorbent Complex The water-absorbing ability of the water-disintegrating superabsorbent complex was measured for physiological saline and artificial urine, using the saturated water absorption, water absorption speed, and load. Lower water absorption,
Performed on wet back.

(2-1) Measurement of water absorption rate of water-disintegrable superabsorbent complex The water absorption rate of the water-disintegrable superabsorbent composite was measured by absorbing 20 ml of the liquid to be absorbed.

(2-2) Measurement of Saturated Water Absorption of the Water-Disintegrable Superabsorbent Complex The saturated water absorption of the water-disintegrable superabsorbent composite was measured by absorbing water by the water demand method and then absorbing water one hour later. The amount was measured.

(2-3) Measurement of water absorption under load of the water-disintegrable superabsorbent composite
Water was absorbed by a water demand method under a load of ³ kPa (20 g / cm ² ), and the amount of water absorption after 1 hour was measured.

(2-4) Measurement of wet-back of water-disintegrable superabsorbent composite The measurement of wet-back of the water-disintegrable superabsorbent composite was carried out by using a water-demand method to absorb water and saturate to 111 kPa. The liquid which returned when a load of (1 ton / m ² ) was applied was sucked into a large amount of tissue paper, and the weight was measured.

(3) Measurement of disposal of the water-disintegrable superabsorbent complex into a flush toilet The measurement of disposal of the water-disintegrable superabsorbent complex into a flush toilet was performed by measuring the water content of the water-disintegrable superabsorbent complex. Dispersibility, pipe passability, and biodegradability in water were measured.

(3-1) Measurement of water dispersibility of water-disintegrable superabsorbent composite The dispersibility of the water-disintegrable superabsorbent composite was tested as follows.

(3-1-1) Measurement of Dispersion Rate by Vibration Test Three water-disintegrable superabsorbent composites which were dried in a desiccator for at least one day to a constant weight were cut, and 0.1 g thereof was cut. 1
Put into an L beaker, pour 500 ml of water into it,
The concentration was adjusted to 0 mg / l. This beaker was set on a vibrator, and the mixture was stirred for 5 hours at speeds of 50, 100, and 150 rpm, respectively. After stirring, open the eyes 5
mm mesh No. The mixture was filtered through a sieve of No. 4 and the residue was dried at 105 to 110 ° C. for 2 hours. After cooling in a desiccator, the weight was measured to determine the dispersion. The dispersion ratio (%) is represented by (W0−W1) × 100 / W0. (W0- is the original weight cut, W1 is the residue on the sieve) (3-1-2) Measurement of disintegration of water-disintegrable superabsorbent complex in water Water-disintegrable superabsorbent complex Fig. 2 shows the disintegration of
5 and in the simulated cleaning tank shown in FIG. FIG.
Is the result of mechanical agitation, FIG. 26 is the result of mechanical agitation, and both are aeration tanks.
The test was performed under the conditions shown in Table 3. First, a test sample was placed in a test tank, and photographs were taken every 3 minutes until the original shape was not retained or until 20 minutes, and evaluated.

[0224]

[Table 3] (3-2) Measurement of pipe permeability of the water-disintegrable superabsorbent composite The pipe permeability of the water-disintegrable superabsorbent composite was measured according to JIS A.
5207-1976 This was carried out using a flush toilet with C316, C416, C317 and C417 and a simulated flush toilet consisting of a low tank of T120. That is,
The simulated toilet shown in FIG. 27 was prepared and tested. In this simulated toilet, since the water distribution pipe from the toilet to the washing tank is made of transparent acrylic resin, it can be confirmed that the water-disintegrating superabsorbent complex passes through the pipe, and the water distribution pipe is The test sample can be taken out because it can be removed just before the charging section into the washing tank.
The test was performed by the following method. First, three water-disintegrable superabsorbent complexes were placed on a toilet, and 8 to 12 L of water was flown from a low tank and tested to see if it passed through a water pipe. Further, the same operation was repeated 50 times to confirm the possibility of blockage (clogging) and other conditions.

(3-3) Measurement of biodegradability of water-disintegrable superabsorbent complex in water The biodegradability of the water-disintegrable superabsorbent complex in water was determined by decomposing microorganisms in a culture solution. The measurement was performed using the obtained bacterial cellulose. First, a culture solution (Dubos solution: NaN
O3 0.5g, KCl 0.5g, K2HPO4
1.0g, Fe2 (SO4) 3.7H2O small amount, Mg
0.5 g of SO4.7H2O, 5.0 g of filter paper, 1000 ml of distilled water, pH 7.5) were prepared and used in a test tube. These were dissolved by stirring at 120 ° C. for 10 minutes in an autoclave.

To prepare cellulose obtained by decomposing microorganisms, 10 ml of the above culture solution was placed in a test tube having a diameter of 16 to 18 mm, and 1 ml of a diluent such as soil or compost was added thereto and cultured. Was used to confirm the resolution.

The culture of the cellulose obtained by decomposing the microorganism was confirmed by observing the condition of the filter paper. The required amount of cellulose obtained by decomposing the isolated microorganism is cultivated in advance in the above culture solution.

In the degradability test, a water-disintegrable superabsorbent composite and a standard cellulose fiber which were dried in a desiccator for one day or more to obtain a constant weight were cut, and 0.5 g of each of the composite and 100 ml of the above solution was prepared. The mixture was placed in a 300 ml flask, 500 ml of water was poured into the flask, and the contents were cultured for 2 weeks while occasionally shaking the contents.

After the cultivation, the contents of each flask were washed off, suction-filtered on a 47 mm-diameter glass filter having a pore of 1 μm in diameter, and then filtered at 105-110 ° C. for 2 hours.
After drying for an hour, it was dried in a desiccator and weighed. The resolution is [(Wk0-Wk1) / W0] [WS1 (W
0 / (Ws0−WS1)] (where the initial weight of the water-disintegrable superabsorbent composite and the cellulose fiber is Wk, respectively)
0 and Ws0, and the remaining weights after cultivation of the water-disintegrable superabsorbent composite and the cellulose fiber were Wk1 and WS1, respectively. ) The samples after both cultures were micrographed and evaluated.

[Compound Production Example 1] 7.2 parts of lysine methyl ester dihydrochloride and 22.6 parts of lysine monohydrochloride were dissolved in 40 parts of distilled water, and 7.8 parts of caustic soda was added little by little. Neutralized and prepared lysine aqueous solution. On the other hand, 100 parts of polysuccinimide having a molecular weight of 96,000 was dissolved in 400 parts of DMF under a nitrogen stream, an aqueous lysine solution was added, and the mixture was stirred at room temperature for 1 hour, stopped stirring, and reacted for 20 hours. The reaction product was transferred to a mixer equipped with a blade with stirring blades, and 400 parts of distilled water and 400 parts of methanol were added.
In 5 minutes, the gel was pulverized, and 129.7 parts of a 27% by weight aqueous sodium hydroxide solution was further added dropwise over 2 hours. After the dropwise addition, the mixture was further stirred for 2 hours, and then the pH was adjusted using 7% by weight aqueous hydrochloric acid.
= 7. After neutralization, further add methanol 30
0 parts were added and the precipitate was dried at 60 ° C. to obtain 143 parts of a water-absorbing polymer. Further, the mixture was pulverized using a sample mill and classified to 100 to 500 μm.

When the water absorption capacity of this resin was measured, the equilibrium swelling absorption was 58 times, the water absorption rate with respect to physiological saline was 27 times per minute, and the water absorption under load was 23. The amount of water was 28 times.

Further, a composite was prepared by using a material pulverized to a size of 100 μm or less.

[Compound Production Example 2] 3.0 parts of hexamethylenediamine was dissolved in 40 parts of DMF, and 7.8 parts of caustic soda was added little by little to neutralize to prepare an aqueous lysine solution. On the other hand, under nitrogen stream, 100 parts of polysuccinimide having a weight average molecular weight of 153,000 was dissolved in 400 parts of DMF, a lysine aqueous solution was added to this solution, and the mixture was stirred at room temperature for 1 hour, stopped stirring, and reacted for 20 hours. Thus, a gel of crosslinked polysuccinimide was obtained. The gel of crosslinked polysuccinimide was transferred to a mixer equipped with a blade with a stirring blade, 400 parts of distilled water and 400 parts of methanol were added, and 8000 rpm was added.
The gel was ground for 5 minutes at.

Further, 129.7 parts of a 27% by weight aqueous solution of caustic soda was added dropwise thereto over 2 hours while maintaining the degree of swelling of the resin within the range of 3 to 100 times. After completion of the dropwise addition, the mixture was further stirred for 2 hours, and then neutralized to pH 7 by adding 7% by weight aqueous hydrochloric acid. After the neutralization was completed, 300 parts of methanol was further added, and the precipitate was dried at 60 ° C. to obtain a crosslinked polyaspartic acid-based resin 12 as a water-absorbing polymer.
5 parts were obtained.

When the water absorption capacity of this resin was measured, the equilibrium swelling absorption was 64 times, the water absorption rate with respect to physiological saline was 28 times per minute, and the water absorption under load was 28. The amount of water was 35 times.

Further, a water-disintegrable superabsorbent composite was prepared by using pulverized material having a size of 100 μm or less.

[Production Example 1 of Water-Disintegrable Superabsorbent Composite] Preparation of Microfibrillated Cellulose Dispersion ・ Preparation of Bacterial Cellulose (BC) Mother Solution BC (BPR) having a solid content of 30% was dissolved in ion-exchanged water by stirring for about 2 hours using a mixer. To prepare a mother liquor having a solid content of 1.2%.

Preparation of BC Ethanol / Water Mixed Solvent Dispersion A predetermined amount of a mother liquor was taken, and ethyl alcohol and ion-exchanged water were added thereto to prepare a 0.02% to 0.80% BC dispersion. . 2. Preparation of Microfibrillar Cellulose / Water Absorbent Resin Coexisting Dispersion Example 1 in 50 cc of a 0.02% to 0.8% BC dispersion.
5 g of the water-absorbent resin prepared in the above was added to prepare a BC / water-absorbent resin dispersion. This dispersion causes precipitation of the water-absorbing resin when the BC concentration is low, but is stabilized when the concentration is high. The system was kept stable while stirring with a stirrer to adjust the system conditions. 3. Formation of water-disintegrable superabsorbent complex The above dispersion was filtered on a Buchner funnel (inner diameter: 11 cm) connected to a pressure reducing device, and a nonwoven fabric substrate (TCF4 manufactured by Nimura Chemical Co.)
03, an apparent density of 0.07 g / cm ³ ), a 20 cc viscous dispersion was quickly poured on the nonwoven fabric of the base material, the solvent was removed under reduced pressure, and then dried with hot air to obtain a water-disintegrable superabsorbent composite. Body. 4. Water absorption of water-disintegrable superabsorbent composite, evaluation of water retention For the above complex, after immersing in a sufficient amount of physiological saline for 30 minutes, the water absorption and water retention were measured according to JIS K-7223, When the value was converted to the content of the water-absorbing resin, the results shown in Table 4 were obtained.

[0239]

[Table 4] [Production Example 2 of Water-Disintegrable Superabsorbent Composite] Using the production apparatus shown in FIG. 18 provided with the coating apparatus shown in FIG. 20,
A water-disintegrable superabsorbent composite was produced. The materials used are as follows. (1) Microfibrillar cellulose: S-MFC (manufactured by specialty paper) (2) Water-absorbing resin: Compound produced in compound production Example 1 (3) Mixed solvent: methanol / water system (4) Coating component composition: Ingredients Weight composition ratio S-MFC 0.4 Crosslinked polyamino acid 30.0 Methanol 48.8 Water 20.8 (5) Sheet support As a sheet support, a two-layered web having the following structure was used. The basis weight 40 obtained by laminating using a water flow
g / m ² and a nonwoven fabric with an apparent density of 0.06 g / cm ³ were used.

Upper layer: rayon (4d × 51 mm) 25 g / m ² Lower layer: polylactic acid spunbond web 15 g / m ² While running the sheet-like support 13 at a speed of 10 m / min, the above-mentioned ( The mixed dispersion of the component (4) was continuously applied with a width of about 10 mm at intervals of 5 mm. Then, after compressing with a roll to remove the solvent, it was dried with hot air. The obtained sheet-like water-disintegrable superabsorbent composite had the following properties.

The water retention of the obtained water-disintegrable superabsorbent composite was measured in accordance with JIS K-7223.
As a result, it showed a water retention of 40.2 g per 1 g of the cross-linked polyamino acid, and a value almost equivalent to that of Blank.

[Example 1] Production of water-disintegrable superabsorbent composite Using the composite produced in Example 2, a test of disposal in a flush toilet was conducted.

The water dispersibility was as good as 90% by a vibration test, and the original shape was not retained at all by visual observation. As a result of the disintegration test using the simulated washing tank, the original shape was not retained within 20 minutes for both air stirring and mechanical stirring. As a result of the pipe passage test, all of the samples flowed without blocking during the 50 tests. As a result of the biodegradability test in water, the degree of decomposition was as good as 45%.

[Comparative Production Example 1] The water absorption capacity of the crosslinked carboxymethylcellulose having biodegradability was measured, and the equilibrium swelling and absorption was 36 times, and the water absorption rate to physiological saline was 12 times per minute. Yes,
The water absorption under load was 12 times and the water retention was 15 times.

[Comparative Example 1 for Production of Water-Disintegrable Superabsorbent Composite]
An absorber was manufactured without using a water-absorbing resin, and its absorption capacity was measured. For physiological saline, the water absorption rate was 0.45 ml / sec · cm ² and the rewetting amount was 0.074 g / cm ² . For artificial urine,
The water absorption rate is 0.55 ml / sec · cm ² , the saturated water absorption is 24 g / cm ² , and the water absorption under load is 18 g
/ Cm ² and the re-wet amount is 0.072 g / cm ²
Met. [Comparative Example 1] Production of water-disintegrable superabsorbent composite A test of disposal in a flush toilet was performed using the composite produced in Comparative Example 1. As for the water dispersibility, the dispersion rate by the vibration test was 2
It was as low as 0%, and it remained in its original form except for a part by visual observation. As a result of the disintegration test using the simulated washing tank, both the air stirring and the mechanical stirring maintained the original shape even after 60 minutes.

[0246]

As described above, the water-disintegrable superabsorbent composite of the present invention can be obtained by converting the water-swellable solid into various forms, for example, powder, particles, pellets, sheets, or arbitrary forms. It can be formed into a form such as a three-dimensional structure having the above-mentioned shape, thereby improving the handleability and expanding the range of use. In particular, when a particulate cross-linked polyamino acid that can be easily and inexpensively obtained by mass production is used, and this is stably maintained in a network structure of microfibrillar cellulose, it is of course possible to use the particulate polyamino acid as it is. In addition, it is possible to easily configure an absorber of any form. In particular, in the case of a sheet-like configuration, the thickness can be reduced while having a very large water absorption capacity, and the overall thickness of absorbent products such as diapers for infants and adults, sanitary napkins and the like is extremely limited. Can be reduced to When the water-disintegrable superabsorbent composite of the present invention is supported on another sheet-like support, it can be used for a wide range of applications as a composite having excellent absorbency.

[Brief description of the drawings]

FIG. 1 is a diagram showing an application example of a water-disintegrable superabsorbent composite to an absorbent article.

FIG. 2 shows an example of a cut-out diaper.

FIG. 3 shows an example of a detachable diaper.

FIG. 4 shows another example of a detachable diaper.

FIG. 5 is a graph showing the relationship between the concentration of microfibrillated cellulose in a solvent and viscosity.

FIG. 6 is an explanatory diagram showing a process of obtaining microfibrillar cellulose from cellulose.

FIG. 7 is a graph showing a relationship between an organic solvent concentration and an absorption ratio of a water absorbent resin.

FIG. 8 is a diagram showing a process of forming various composites from a slurry-like dispersion.

FIGS. 9A and 9B are cross-sectional views showing a form of a composite according to the first embodiment of the present invention, wherein FIG. 9A shows a particulate form and FIG. 9B shows a flake form.

10A and 10B show a composite according to a second embodiment of the present invention, wherein FIG. 10A is a longitudinal sectional view, and FIG.

FIGS. 11A and 11B show a composite according to a third embodiment of the present invention, wherein FIG. 11A is a longitudinal sectional view, and FIG.

FIG. 12 is a longitudinal sectional view of a composite according to a fourth embodiment of the present invention.

FIG. 13 is a longitudinal sectional view of a composite according to a fifth embodiment of the present invention.

FIG. 14 is a longitudinal sectional view of a composite according to a sixth embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of a composite according to a seventh embodiment of the present invention.

FIG. 16 is a partial perspective view of a composite according to an eighth embodiment of the present invention.

FIG. 17 is a longitudinal sectional view of a composite according to a ninth embodiment of the present invention.

FIG. 18 is a flow chart of a process for producing a composite according to the method of the present invention.

FIG. 19 is a flowchart showing a modification of the step in FIG. 18;

20 is a longitudinal sectional view of another coating apparatus used in the flow shown in FIG.

FIG. 21 is a plan view of a grooved roll used in the apparatus of FIG. 20;

FIG. 22 is a cross-sectional view of a sheet-like support on which a mixed solvent layer is applied by the apparatus shown in FIGS.

FIG. 23 is a diagram showing a longitudinal section of a water-disintegrable superabsorbent composite.

FIG. 24 is a perspective view of an apparatus for producing a water-disintegrable superabsorbent composite.

FIG. 25 is a view showing a simulated washing tank for a water disintegration test.

FIG. 26 is a diagram showing another simulated washing tank for a water disintegration test.

FIG. 27 shows a dummy toilet.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Unwinding roll 2 Spray nozzle for temporary fixing solution 3 SAP supply feeder 4 Spray nozzle for microfibrillar cellulose 5 Heat roll 6 Immobilized SAP layer 7 Super absorbent sheet 10 Water disintegrable super absorbent composite layer 11 Microfibril Cellulose 12 SAP particles 13 Sheet support 14 Liquid-impermeable nonwoven fabric 15, 23 Bonding section 16 Channel 21 Liquid-impermeable sheet 22 Highly water-absorbent composite sheet material 24 Channel 31-34 Tank 35-37 Mixer 40 Molding section 41 Belt conveyor 42 Nozzle 43 Roll press 44 Bath 45 Dipping roll 46, 47 Roll 46a Groove 48 Mixed solvent layer 50 Drying section 51, 52 Heating roll 60 Compression section 61, 62 Press roll

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61F 5/44 D04H 1/42 G 4L047 B01J 20/26 1/58 A 4L055 B32B 5/24 A41B 13/02 D D04H 1/04 M 1/42 A61F 13/18 300 1/58 383 (72) Inventor Yoshihiro Iriya 580-32 Takuji, Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc. (72) Higuchi, Inventor Chojiro 580-32, Takuji, Nagaura, Sodegaura-shi, Chiba Prefecture Mitsui Chemicals, Inc. (72) Inventor Takeshi Ishitoku 580-32, Takuji, Nagaura, Sodegaura-shi, Chiba F-term (reference) 3B029 BA12 BC02 BC06 BC07 BD21 4C003 AA12 AA23 AA25 HA04 4C098 AA09 CC02 CE05 CE06 DD05 DD23 DD30 4F100 AJ04B AJ05C AJ05E AJ06C AJ06E AJ06H AJ20B AK01A AK21C AK21D AK21E AK05A AK46A AP01C AP01D AP01E AR00B AR00D AR00E AT00C BA03 BA05 BA07 BA10D BA10E DE01A DG01B DG01C DG01D DG02B DG02C DG02D DG02E DG14D DG18D GB66 JA20B JB09D JB09E JB10D JB10E JB20C JB20E JC00 JC00A JD05D JD05E JD15 JD15A JL00 JL11B JM01A JM01B JM01C YY00B 4G066 AC02C AC12D AC26B AC35B AE06B AE20B AE20C BA03 BA17 BA20 CA43 DA11 DA12 DA13 EA05 4L047 AA08 AA12 AB02 AB10 BA21 BA23 BC05 CA06 CB07 CC03 CC04 CC05 4L055 AA01 AF09 AF10 AG45 AG46 AG64 AG80 AG93 AG98 AH37 AH50 AJ02 BE14 EA40 FA20 FA30 GA26 GA28 GA46

Claims (28)

[Claims] 1. An absorbent component (A component) mainly composed of a water-absorbent resin, a support component (B component) carrying the absorbent component (A component), and the mutual water-absorbent resin and the water-absorbent component. A superabsorbent composite comprising a resin and a binding component (C component) for binding the support component, wherein the absorbent component (A component), the support component (B component), and the binding A water-disintegrable superabsorbent composite, wherein each of the components (C component) has water dispersibility. 2. The water-disintegrable superabsorbent composite according to claim 1, wherein the absorbing component (A component) is composed of biodegradable crosslinked polyamino acid particles. 3. The water-disintegrable superabsorbent composite according to claim 1, wherein the support component (component B) is a tissue mat composed of wood pulp fibers. 4. The method according to claim 1, wherein the support component (component B) is composed mainly of wood pulp fibers and is formed by mixing fibers having a fiber length of 25 mm or less into a mixed sheet. Water-disintegrable superabsorbent composite. 5. The support component (B component) has a fiber length of 25.
The cellulose fiber selected from the group consisting of rayon, cotton, and lyocell having a size of not more than 1 mm, and a binder composed of polyvinyl alcohol or a partially crosslinked product thereof is used. Water-disintegrable superabsorbent composite. 6. The support component (B component) has a fiber length of 25.
The cellulose fiber selected from the group consisting of rayon, cotton, and lyocell having a size of 1 mm or less, and comprising a binder composed of an alkaline earth metal salt of carboxymethyl cellulose. Water-disintegrable superabsorbent composite. 7. The water-disintegrating superabsorbent composite according to claim 1, wherein the binding component (component C) is composed of microfibrillar cellulose having a water retention of 250% or more. 8. The water-disintegrating superabsorbent composite according to claim 1, wherein the binding component (component C) is composed of microfibrillated cellulose obtained by highly disintegrating wood pulp. 9. The water-disintegrable superabsorbent composite according to claim 1, wherein the binding component (C component) is composed of bacterial cellulose (BC). 10. An absorbent article comprising a liquid-permeable top sheet, an absorbent having liquid-absorbing / liquid-retaining properties, and a liquid-impermeable backing sheet, wherein the absorbent is provided.
An absorbent article comprising the water-disintegrable superabsorbent composite according to item 1. 11. The absorbent article according to claim 10, wherein said topsheet is made of a water-disintegrable sheet. 12. The absorbent article according to claim 10, wherein the back sheet is made of a water-disintegrable sheet. 13. The absorption component (A component), the support component (B component), and the binding component (C component) have biodegradability.
The absorbent article according to any one of the above. 14. The absorbent article according to claim 10, wherein both the topsheet and the absorbent have biodegradability. 15. The absorbent article according to claim 10, wherein the top sheet, the absorber, and the back sheet all have biodegradability. 16. The surface sheet according to claim 10, wherein the surface sheet is mainly composed of wood pulp fibers, and is a sheet formed by mixing fibers having a fiber length of 25 mm or less. Absorbent article. 17. The method according to claim 17, wherein the topsheet is mainly composed of cellulose fibers selected from the group consisting of rayon, cotton and lyocell having a fiber length of 25 mm or less, and a binder comprising polyvinyl alcohol or a partially crosslinked product thereof. The absorbent article according to any one of claims 10 to 15, comprising: 18. A binder wherein the topsheet is mainly composed of cellulose fibers selected from the group consisting of rayon, cotton and lyocell having a fiber length of 25 mm or less, and a binder comprising an alkaline earth metal salt of carboxymethylcellulose. Claims 10-1 characterized by including
5. The absorbent article according to any one of 5. 19. The back sheet according to claim 10, wherein the back sheet is made of a joined body of a tissue-like mat made of a polyvinyl alcohol film and wood pulp fibers.
The absorbent article according to any one of the above. 20. The back sheet comprising a polyvinyl alcohol film and wood pulp fibers as main components, and a sheet formed by mixing and molding fibers having a fiber length of 25 mm or less. Item 1
The absorbent article according to any one of 0 to 15. 21. The back sheet mainly composed of a polyvinyl alcohol film and cellulose fibers selected from the group consisting of rayon, cotton and lyocell having a fiber length of 25 mm or less, and polyvinyl alcohol or a partially crosslinked product thereof. The absorbent article according to any one of claims 10 to 15, wherein sheets formed by a binder comprising: 22. An alkaline earth metal salt of carboxymethyl cellulose, wherein the back sheet is composed mainly of a polyvinyl alcohol film and cellulose fibers selected from the group consisting of rayon, cotton, and lyocell having a fiber length of 25 mm or less. The absorbent article according to any one of claims 10 to 15, wherein sheets formed by bonding a sheet with a binder are bonded. 23. The absorbent article according to claim 10, wherein the absorbent is removably arranged. 24. The apparatus according to claim 10, wherein the absorber and the topsheet are removably arranged.
5. The absorbent article according to any one of 5. 25. An absorbent body comprising a liquid-permeable top sheet, an absorbent having liquid absorbing / liquid retaining properties and a liquid-impermeable back sheet, and at least partially joined to the absorbent body, and In the absorbent article comprising an outer member that surrounds the waist from the abdomen of the wearer and allows the wearer to wear the absorber portion around the waist and maintains the state, the topsheet, the absorber and the absorber The absorbent article according to any one of claims 10 to 15, wherein the back sheet is integrally detachably disposed. 26. An absorbent body comprising a liquid-permeable top sheet, an absorbent having liquid-absorbing / liquid-retaining properties, and a liquid-impermeable backsheet, and at least partially joined to the absorbent body, and An exterior member surrounding the waist from the abdomen of the wearer and holding the absorber body against the wearer, and joining opposite side edges of a front body and a rear body of the exterior member to form a waist around An absorbent article in which an opening and a pair of leg openings are formed, and a stretchable elastic member is arranged along the opening, wherein the absorber main body is arranged detachably from the outside. Items 23 to 25
The absorbent article according to any one of the above. 27. A disposable absorber main body comprising a liquid-permeable top sheet, an absorbent having liquid absorbing / liquid retaining properties and a liquid-impermeable back sheet, and a wash-resistant cover for holding or covering the same. The absorbent article according to any one of claims 23 to 25, wherein a part or all of the absorbent has water disintegrability. 28. An absorbent article using a combination of the disposable absorbent body and a wash-resistant cover, wherein the disposable absorbent body can be externally attached and detached while the cover is always worn. 28. The absorbent article according to claim 27, wherein