KR840001928B1 - Compositions for immobilization of particulate absorbents - Google Patents

Abstract

Immobilized particulate absorbent is prepared from a waterinsoluble, water-swelling absorbent polymer(A) and a liquid polyhydroxy organic compd.(B). (A) has a gel capacity of more than 10 and is selected from a polysaccharide transformed from polyacrylate, cross-linked synthetic polyacrylate, cross-linked carboxymethyl cellulose, cross- linked polyalkylene oxides or rubber. (B) has a vicinal hydroxyl gp. and is selected from glycerol, ethylene glycol or propylene glycol. The composition of (A) and (B) is 25-125 and 100 by parts, respectively.

Description

Absorbent Immobilization Composition

The present invention relates to an absorbent passivating composition.

The present invention relates in particular to absorbent products, particulate absorbent immobilization methods and compositions and absorbent articles made therefrom. Absorption of the mobile aqueous solution was conventionally performed using a sponge or a core surface. More recently, water insoluble or water swellable aggregates with high absorption capacity have been developed for passivating water and aqueous fluids.

These polymers are not structurally perfect as particulates, ie powders or granules. These polymers are commonly referred to in the art as superabsorbents hydrogels or hydrocolloids, and are incorporated into cellulose absorbent structures in diapers, menstrual bands and other absorbent articles to improve the absorption efficiency of these absorbers. Increase. The benefits that can be expected from the mixing of these particulates are generally reduced by the movement of particulates, which requires special construction for the immobilization of the particulates in the structure of these articles. Therefore, there has been a need for a method of reducing the migration of particulate adsorbent material and a product in which the particulate adsorbent remains uniform.

U. S. Patent No. 3,900, 030 describes menstrual spheres using an open-celled polymer foam embedded with a water swellable polymer therein. In doing so, structural integrity of the absorbent polymer could be achieved, but flexibility in use is constrained by the foam carrier. In addition, the disposal method is constrained by the foam carrier.

The present invention has been accomplished by discovering that the polymer absorber can be immobilized by mixing together the particulate water-insoluble water swellable polymer absorber and the liquid polyhydroxy organic compound. A passivating composition composed of a polymer absorbent and a liquid polyhydroxy organic compound can be used to prepare a novel product in which the absorbent is converted into a nonparticulate passivated form such as an absorbent having a solidifying structure. When the composition contains a blowing agent, the composition becomes a foamable passivating composition and the absorbent having a solidifying structure becomes a foam product. In the absorbent passivating composition, 25 parts by weight to 125 parts by weight, and preferably about 40 parts by weight to 80 parts by weight based on 100 parts by weight of the liquid polyhydroxy organic compound, are used. Compositions suitable for preparing foam products additionally contain from about 2 to about 30 parts by weight of blowing agent.

The absorbent passivating composition, with or without foaming agent, may be (a) fabricated, coated or cold pressed onto a suitable surface to produce a glass film or glass plate, or (b) coated on a permanent surface such as a substrate to form a film film. Or (c) foam forming compositions, which may be foamed in suitable places. These products have structural integrity during the solidification process as described below, have good absorption efficiency, are self-supporting, and can be disassembled and disposed of after use.

The absorber products of the present invention are structurally stable solids that swell rapidly upon absorption of fluid, are resilient and slightly elastic. In addition, since these products have water acidic particle characteristics that can be decomposed into excess water, it is very convenient to dispose of them after performing the required functions.

In the case where the absorbent product of the present invention is a foamed product, the conventional sponge has a very high fluid absorption capacity because the aqueous solution absorption capacity is determined by the absorption capacity of the polymer absorbent and is not limited by the original foam structure dimensions. It is very different from my solid foam.

The product of the present invention also has the advantage that it can be easily prepared from a non-toxic liquid foaming composition which can be easily processed without the need of adding water or an organic solvent.

The absorbent article having the particulate absorbent immobilized with the absorbent-containing solidifying structure according to the present invention has a high absorbent capacity which is not reduced by the movement and agglomeration of the particulate absorbent involved in transportation and handling before use. Moreover, the absorption is hardly reduced by the presence of the solidifying structure surrounding the absorber particles. Absorption of the aqueous solution is practically instantaneous. This phenomenon is entirely unexpected given that the presence of the carrier usually reduces the absorption rate.

The absorbent product of the present invention is useful as a sole or auxiliary absorbent sheet material in absorbent articles such as bad pads, hygiene products, diapers, urine incontinence pads and the like.

When the absorbent product of the present invention is used as a single absorbent plate, it can be directly applied to a permanent substrate and used as an absorbent article, for example, a diaper support. Suitable substrates for this purpose include, for example, films such as polyethylene films, nonwoven cellulose materials, woodpulp materials and the like. However, in combination with wood pulp plates and other absorbent materials used in the core surface, the effect of reducing the size or thickness may be obtained.

When the product of the present invention is a foam, not only has excellent absorption capacity, but also has a warm feeling and elasticity, thereby providing comfort without making the thickness of a conventional core surface. Relevant applications for the use of the absorbent products of the present invention, particularly in the form of foams, on flexible substrates are medical or surgical bandages and sponges.

When the product of the present invention is a foam, its resilience and some elasticity properties are particularly useful where it requires both absorption and cushioning, such as the packaging of unusually shaped structures. Since the foam of the present invention is made from non-toxic materials, it can be easily foamed in place. However, the foam is stable and can be manufactured in any size and shape required and can be stored with or without a support structure. If necessary, it can also be cut into the shape required for end use. Applications for both absorption and buffering include inner walls of fragile materials such as radioactive solutions and glass used for transporting biological fluids, double walls for aqueous solution fluid transport, or protective liners for double containers. . If the container requires a special material, such as an outer one for the radioactive fluid, it is desirable to reuse this one.

The foam product of the present invention has the advantage that it can be easily removed from the container by washing the container with an excess amount of water.

As used herein, the term "absorbent" refers to a water-insoluble, water-swellable polymer that has an excellent capacity for removing water or aqueous fluids, as described below. Water-insoluble, water-swellable polymers are weakly cross-linked polymers that have a sufficient proportion along the polymer chain with a number of shallow water groups, such as carboxyl, carboxamide, sulfonate or sudoxy groups, so that if the crosslinks in the polymer break, It becomes water availability.

Hydrophilic groups in these polymers constitute from 25% to 72% of these molecular structures. These materials have a molecular weight or degree of crosslinking sufficient to be water insoluble during the wettable period. Most suitable materials are compounds reported to have an average molecular weight in the range of about 13,000 to 300,000 per crosslink, but are by no means limited to these materials. The most common and best known materials are polyacrylate modified polysaccharides, crosslinked synthetic polyacrylates, crosslinked carboxymethylcelluloses or crosslinked pulleys (alkylene oxides), as defined below.

Xanthan rubber, low kissed rubber, guar rubber and other graft polymers or mixtures thereof with analogues or mixtures thereof are also suitable to meet the requirements of water insolubility and water swellability. The water insoluble water swellable polymer has a gel capacity of about 10 or more. "Gel capacity" means the weight of an aqueous solution fluid that can be absorbed and held per unit weight polymer, ie, the number of grams of fluid per 1g polymer. In other words, the absorbent polymer has an absorbent capacity of at least 10 times the weight of the foreign matter in dry form. This dose may amount to 1,500 or more times the weight of the dry form material. It is usually about 15 to 70 times the dry weight. This material is commonly referred to in the art as "hydrogel", "hydrocloid" or "superabsorbent". Many water swellable polymers are commercially available.

The polymer is used in particulate form. By "particulate" is meant a finely divided particulate matter. These particles can be formed in various forms, such as spherical, circular, angular, needle-shaped, amorphous or fibrous. The particle size is usually in the range of diameters or cross sections (maximum diameter when not spherical) of about 1 micron to 2 × 10 ⁴ microns. The particles are preferably finely divided powder particles of about 1 to 10 ³ micron particle size. By "absorbent passivating composition" is meant a composition which contains particulate water-insoluble water swellable polymers and liquid polyhydroxy organic compounds and may also contain the blowing agents and / or minimal amounts of non-essential additives described below. This composition is an excipient that immobilizes the particulate absorber.

The liquid polyhydroxy organic compound used in the present invention is a high boiling liquid having at least two hydroxy groups, preferably vicinal or adjacent hydroxy groups. Suitable liquids include glycerol, ethylene glycol, propylene glycol and analogs thereof, with glycerol and ethylene glycol being suitable.

Non-gaseous reagents that decompose into blowing agents in the foamable absorbent passivating composition to produce gas may be used, and examples thereof include azo compounds such as sodium bicarbonate and azodicarbonamide, P-toluenesulfonyl semicarbazide, P, P-oxybisbenzenesulfonyl hydrazide, P-toluenesulfonyl hydrazide, its analog, etc. are mentioned.

In certain aspects of the present invention, a non-foamable absorbent passivating composition may be used and the blowing agent may be a gas such as air, nitrogen, carbon dioxide, and the like. In addition to the components described above, the composition may contain a minimum amount of other additives that can impart the required properties to the absorbent product. Thus, surface active humectants, in particular nonionic surfactants, may be included to enhance liquid absorption. Surfactants have particular advantages in helping the vertical transport of liquids.

Representative surfactants are common compounds described, such as alkylaryl polyether alcohols or alkylphenyl ethers of polyethylene glycol, such as the reaction products of ethylene oxide and t-octylphenol or nonylphenol. Fine fiber celluloses such as cellulose powder, silicates and the like also have a similar effect. Activated carbon or other adsorbents may be included for odor removal. Fragrances, colorants and the like can be used to give a refreshing feeling. Inserts containing bound water such as silicates, aluminum hydrates and the like can be used to modify the texture of the sheet. Similar results can be achieved with slightly moist ethylene glycol or glycerol, such as commercial glycerin. If the absorbent passivating composition contains a low amount of powder absorbent, the absorbent tends to be fixed.

The composition may be modified to contain small amounts of materials that affect its dispersibility. Suitable viscosity modifiers include silicate powders, clays, zinc oxides, inert fillers and the like. It is also possible to modify the polyhydroxy compound with a minimum amount of liquid modifier such as ether glycol, mineral oil, etc., which is not designed as an essential component of the present invention composition. In general, when additives are used, they do not exceed more than about 25% of the total composition.

The term "absorbent solidifying structure" refers to a liquid composition obtained by coating a liquid composition on a substrate surface or a carrier surface or on a metal surface or a glass film, sheet or foam sheet molded article or, in the case of a foamable composition, a container after solidifying these liquid compositions. It means a solid body.

When the absorber-containing solidifying structure is a film or sheet, whether in the form of foam or non-form, these structures may form a continuous film or a discontinuous film and may also be of a lattice type structure. It may also be filamentary as described below.

As used herein, the term "film" means a thickness of up to about 10 mils. The term " sheet " is meant to have a thickness of 10 mils or more and can be non-form or foam. Suitable structures are foam type and non-form type sheets.

The method for immobilizing the particulate absorbent and manufacturing the absorbent-containing solidifying structure comprises absorbing the immobilized composition comprising an absorbent and a liquid polyhydroxy organic compound prepared by mixing the absorber and the liquid polyhydroxy organic compound together on a temporary or permanent surface. Application is carried out. The amount of absorbent used varies within a predetermined range depending in part on the viscosity of the liquid polyhydroxy organic compound used as excipient as well as the amount required by the final product.

When the absorbent solidifying structure is a foam, the structure can be prepared by mixing the components regardless of the mixing order to prepare the absorbent immobilized foamable composition and treating the composition under foaming conditions to obtain the required foam product. . Thus, this composition is prepared by first mixing a suitable water-insoluble water-swellable polymer and a blowing agent together, then adding a liquid polyhydroxy organic compound to the dry mixture and then stirring until it is homogeneous to obtain a foamable absorbent passivating composition. Can be. Alternatively, the polymer and the liquid polyhydroxy organic compound may be mixed together, and then a blowing agent may be added to obtain a foamable absorbent passivating composition.

The foam structure may also be prepared from a non-foamable composition as described in detail below. Compositions in which the polymer absorber is added to the liquid polyhydroxy organic compound are subject to time constraints in fluidity and mobility. These compositions are preferably prepared several hours before or within 24 hours of use, although some absorbent immobilizing compositions may be in liquid form for longer periods of time.

The liquid absorbent passivating composition may then be applied to the temporary or permanent surface. The permanent surface is hereinafter referred to as the substrate. In order to manufacture films, sheets, foam sheets or coating materials, the conventional methods used for coating or film manufacturing, such as knife coating, spray coating, reverse roll coating, gravure coating, cold compression coating or address and the like, can be used. It is available.

Preferred methods are cold extrusion coating and knife coating. Cold extrusion coating methods can be used to prepare foam structures from passivating compositions that do not contain particulate blowing agents. In this method, the inert gas as the blowing agent is injected downward into the extrusion chamber at the time when mixing is completed to foam the mixture and to produce a viscous foamed extrudates, which are then coated by a known method. Another method for producing a foam structure from a passivating composition that does not contain a blowing agent is to air-treat the above-mentioned composition and then coat it by a known method. Particularly convenient is a continuous process using a cold extruder with a heated die to produce an absorbent foam sheet or strip.

내지 400℉ 온도범위로 유지된 다이에 송입하여 발포시켜서 고형 포옴생성물을 제조하고 또 이어 포옴생성물을 다이 오리피스를 통해 영구 또는 임시 기재상으로 방출시킨다. 발포제를 분산시키는 장소는 가스상 발포제를 사용하는지 아니면 비가스상 발포제를 사용하는지에 따라 달라진다. 고체 또는 액체인 경우는 압출기 호퍼로 공급된다.In this method, the components, i.e., particulate water-insoluble, water-swellable absorbent polymers, liquid pulleyhydroxy organic compounds and blowing agents as essential ingredients, are fed to the extruder with a minimum amount of a humectant and other optional additives and passed through the extruder barrel at room temperature. In order to mix the ingredients intimately, then the mixture is about 200

The foam is fed into a die maintained at a temperature between 400 ° F. and foamed to produce a solid foam product, which is then released through the die orifice onto a permanent or temporary substrate. Where to disperse the blowing agent depends on whether gas or non-gas blowing agents are used. If it is a solid or liquid, it is fed to the extruder hopper.

In the case of gas, it is injected from one downward point in the extruder chamber. Multislot dies are used where dies require a single-slot die when strips are required. The substrate may be a permanent substrate such as when the foam layer is a foam coating on the substrate, or may be a temporary substrate such as silicone liner when an unsupported foam sheet is required. When intended for substrate coating, the substrate is of a material commonly used in absorbent articles such as cellulose, vinyl film, polypropylene, polyester, polyethylene, nylon, metal foil, elastomers, textiles, various nonwoven fibers and the like. .

The coating on the substrate can be a substrate front coating, a strip coating or any other predetermined shaped coating. When used as a glass film, sheet or foam sheet, the coating should be on a material previously coated with a release agent such as silicone or on a metal surface. If the passivating absorbent structure is a foam for use in an amorphous shaped device, the liquid composition may be injected into the area of the amorphous shape.

The foamable composition contained in the coated substrate, the coated sheet forming surface, or the irregularly shaped device undergoes a temperature-time relationship to transform the liquid composition into a solid passivating absorbent structure in the form of a film, sheet, coating or foam product.

The conversion of the liquid absorbent passivating composition from the liquid-solid mixture to the solid film, sheet or foam may proceed in a short time of about 15 minutes at temperatures of up to 175 ° F., but typically from 175 ° F. to 450 ° C. for about 30 minutes to 24 hours. In the elevated temperature of < RTI ID = 0.0 > [deg.] C. (79 [deg.] C. to 111 [deg.] C.), ≪ / RTI >

In preparing the foam, the foamable passivating composition may be foamed by placing it in a suitable container or on a substrate or surface for foam formation and left at an appropriate temperature. If foaming rates are required, they can be achieved by heating the liquid composition for about 1 to 60 seconds in the temperature range of about 200 ° F. to 450 ° F. (93 ° C. to 111 ° C.).

In addition to temperature, a factor affecting the rate of solidification is the amount of polymer absorber. For example, a composition having a high absorbent content of at least about 50 parts for a 100 parts liquid polyhydroxy compound solidifies at ambient temperature and within a time period measured in hours, but when the amount of absorber is small, the time required to complete the solidification structure formation is low. Is increased.

It has been found that solidifying structures are formed more rapidly with more viscous liquid polyhydroxy compounds. However, with more viscous polyhydroxy compounds, the final polymer absorber content of the solidified structure is generally lowered because of the difficulty in producing a homogeneous composition.

Thus, for example, a film or foam weeded with glycerol as a polyhydroxy compound will generally have less absorbent content than that produced with ethylene glycol as the polyhydroxy compound. However, as described above, in order to obtain the highest absorption efficiency of the final product, it is preferable to have a liquid polyhydroxy compound as a main component. The preferred film or sheet, whether foamed or not, contains from about 40 to 80 parts by weight of the absorbent with respect to 100 parts by weight of the polyhydroxy compound.

The particulate absorber in the absorbent-containing solidifying structure is firmly supported so as not to move on this film or lattice and conserves the high absorbent capacity of the particulate absorbent if it does not move or push in the final absorbent article. Liquid absorbent passivating compositions, in particular without blowing agents, are not only useful as starting materials for the above-mentioned solidifying absorber-containing films or structures, but also in liquid form and can also be used in aqueous solutions from bandages, skin, human secretions as well as other sources. .

Many water-insoluble and water-swellable polymers suitable as absorbers are commercially available. These polymers can also be prepared by cross-linking a previously produced water-soluble linear polymer or by polymerizing a suitable monomer, or by polymerizing a monomer with a comonomer to simultaneously polymerize and cross-link or by incorporating a hydrophilic group into the finished polymer. An example of post-incorporation of a hydrophilic group into the finished polymer is a method of sulfonating and incorporating sulfonic acid residues. If it is desired to have a hydrophilic group in salt form, the polymer is first brought into phase, ester, amide or nitrile and the product is hydrolyzed in whole or in part.

Preferred polymers have acrylates in these molecular structures. These polymers are fully synthetic acrylate polymers or acrylate modified polysaccharides such as acrylate modified starch or acrylate modified cellulose and the like. By "acrylate modification" is meant that the acrylate polymer or pulley acrylate as described below is graft copolymerized onto a polysaccharide. As used herein, “acrylate polymer” or “polyacrylate” includes not only polymers containing acrylate bases but also polymers containing acrylamide groups, acrylic acid groups, acrylic ester groups or acrylonitrile groups. Preferred synthetic acrylate polymer absorbers are absorbers having base, acid groups or absorbers having both amide groups and base or acid groups. These absorbers are described in the literature, for example in US Pat. No. 3,686,024, the following general formula:

Is indicated.

Wherein A is an alkali metal ion or hydrogen such as sodium or potassium, n is from about 0.5 to about 0.9, 1-n defines the degree of hydrolysis, and n is the number of mer units between crosslinks. to be. Polyacrylate absorbers containing both amides and carboxyl groups include (1) free radicals containing bifunctional organic crosslinks such as acrylamide and N, N-methylenebisacrylamide, as described in more detail in US Pat. No. 3,247,171. Water swellable, crosslinked polyacrylamide is prepared by aqueous polymerization in the presence of a catalyst, followed by partial hydrolysis in an aqueous alkali solution to produce a crosslinked polymer having both an amide and an alkali metal carboxyl group, or (2) the aforementioned United States Patent As simultaneously described, copolymerization of acrylamide and alkali metal alkali salts in the presence of a crosslinking monomer such as N, N-methylenebisacrylamide in the presence of a catalyst system such as 1: 1 ammonium persulfate and β-dimethyl-aminopropionitrile. Or (3) described in US Pat. No. 4,192,727. As can be prepared by radiation polymerization and replacement bonds.

Polyacrylate absorbers can also be prepared by high energy radiocrosslinking of linear polyacrylates as described in US Pat. No. 3,229,769 or by chemical polymerization and crosslinking as described in UK 719,330 and in advance. It can also be prepared by crosslinking the produced polyacrylamide.

Acrylate modified polysaccharides are compounds having polyacrylate chains graft polymerized to cellulose or starch molecules. As these compounds, graft polymers of polysaccharides having hydrophilic chains graft copolymerized onto the compound are preferable. The term "hydrophilic chain" refers to polymer chains prepared from monomers which are water-soluble or hydrolyzed to form water-soluble monomers such as carboxyl groups, sulfone groups, hydroxy groups, amide groups, amino groups, quaternary monomonium groups and their hydrolysates. it means.

In the polysaccharide acrylate polymer, the following general formula;

및

는 각각 산, 에스테르, 알칼리금속, 암모늄염 또는 아미노 기이고, 각개의 R은 각각 수소나 저급알킬이며, r은 0 내지 약 5,000의 정수이고, 또 s는 0 내지 약 5,000의 정수이며, 또 r+s는 500 이상이다. 다당류 아크릴레이트 중합체는, 녹말이나 또는 셀룰로오스 뼈대에의 친수성 물질의 그라프트 형성을 친수성 중합체물질의 생성과 동시에 이룩하고, 또 필요한 경우에는 가수분해를 행함으로서 올레핀성 불포화 사슬을 셀룰로오스와 녹말에 그라프트 공중합시키는 공지방법을 사용해서 제조될 수 있다. 그래서, 중합체는 적당한 다당류를 아크릴로니트릴, 메타크릴로니트릴, 아크릴산메틸 또는 아크릴산에틸, 아크릴산 또는 메타크릴산과 같은 적당한 아크릴단량체와 또는 아크릴아미드 또는 메타크릴아미드와 중합시키고, 이어 알카리 가수분해를 하거나 또는 아크릴산이나 메타크릴산의 알칼리, 금속염을 적당한 다당류로 중합시켜서 제조할 수 있다.The hydrophilic chain of is attached to the skeleton of cellulose or starch molecules by carbon bonds. In the above formula,

And

Are each an acid, ester, alkali metal, ammonium salt or amino group, each R is each hydrogen or lower alkyl, r is an integer from 0 to about 5,000, s is an integer from 0 to about 5,000, and r + s is 500 or more. The polysaccharide acrylate polymer grafts olefinic unsaturated chains to cellulose and starch by forming graft formation of hydrophilic material on starch or cellulose skeleton simultaneously with the production of hydrophilic polymer material and hydrolysis if necessary. It can be manufactured using a known method of copolymerization. Thus, the polymer polymerizes a suitable polysaccharide with a suitable acryl monomer such as acrylonitrile, methacrylonitrile, methyl acrylate or ethyl acrylate, acrylic acid or methacrylic acid or with acrylamide or methacrylamide, followed by alkali hydrolysis or The alkali and metal salts of acrylic acid and methacrylic acid can be prepared by polymerizing with an appropriate polysaccharide.

The polymerization is carried out in an aqueous medium in the presence of a free radical catalyst system or by irradiation (ultraviolet, gamma or X-radiation). The catalyst system used in the aqueous medium usually contains an inorganic oxidizing agent as an initiator and an inorganic reducing agent as an activator. Representative oxidative initiators include inorganic persulfates, peroxides and alkali metal bromates and alkali metal clomates. Representative reducing agent actives include alkali metal bisulfites, alkali metal sulfides, ferrous ammonium sulfate and alkali metal thiosulfates.

As described in more detail in US Pat. No. 4,028,290, the process proceeded to graft polymerization using a catalyst system, the acryl monomer in an aqueous immiscible organic liquid containing an inorganic oxidizing initiator and an inorganic reducing agent activator as an aqueous solution each containing a minimum amount of a water miscible solvent It is optionally added to a reaction medium consisting of an aqueous solution of comonomer crosslinking monomer and a dispersion of powdered or fibrous water insoluble water swellable polysaccharides to obtain an acrylate modified polysaccharide product.

Other suitable methods for chemical catalytic graft polymerization are described in US Pat. Nos. 3,256,372, 3,661,815, 4,076,663, 3,889,678 and 4,105,033. Suitable polysaccharide acrylate polymers are polymers in which the hydrophilic chain attached to the skeleton is in the range of about 10% to about 90% by weight, usually about 40 to 80% by weight of the polysaccharide acrylate polymer. Other suitable water insoluble, water swellable polymers include, for example, cross-linked carboxymethylcellulose prepared by the methods described in US Pat. No. 2,639,239, and US Pat. Nos. 3,956,224, 3,264,202, 3,957,605 and 3,898,143 Mixtures of organic materials of polysaccharide nature, such as cross-linked poly (alkylene oxides) and natural or synthetic rubbers having a molecular weight of 100,000 or more, prepared by the method as described in the heading.

It is known that when rubber is used, it must be used as a mixture. When used in mixtures, it is believed that usually flexible polysaccharide rubbers interact to have the desired swellability without undesirable solubility. Typical rubbers that can be used in the mixtures include soy rubber, guar rubber, xantham rubber, tragacanth rubber, karaya rubber and the like.

Rubber mixtures as well as absorbent polymers as described above are commercially available under various trade names. Water-insoluble, water-swellable polymers prepared according to any of the methods described above are generally obtained as a hard, brittle solid. These polymers can be ground to suitable sizes. As defined above, these polymers are preferably used in powder form, but may also be used in other forms.

Suitable liquid polyhydroxy compounds obtainable from the commercially available hydroxy compounds are extremely limited and practically as defined above. Commercial grade excipients are suitable. It is not necessary to dry these excipients before use. Although a liquid, such as propylene glycol, acts to form the required film, the gentleness of the film formation rate is not very satisfactory in the use of these compounds in the present invention related to the passivation method.

If the solidifying structures are films or foam sheets, these structures may form only part of the moisture absorbent construct of the absorbent article. However, as described above, these solidifying structures may be made of glass films or glass foam sheets and may be used in permanent absorbent articles to constitute the entire moisture absorption site thereof. These articles may be used where a hygroscopic body is needed.

The absorbent product as a glass absorbent film or sheet may be formed by casting a liquid absorbent passivating composition consisting of about 25 to 125 parts of a particulate absorbent polymer in 100 parts of a liquid polyhydroxy organic compound on a metal surface or by coating on a silicon or other release agent adhesion surface. It is also preferably prepared by solidifying the liquid composition by heating to a temperature of 175 ° F. to 450 ° F. for a few seconds to about 15 minutes or by leaving the temperature reaching 175 ° F. for about 30 minutes to about 24 hours. The absorbent product as a coating on a substrate is prepared by coating a permanent substrate under the same drying.

As the solidifying structure the absorber product may be in filament form or in rope form. Such a form can be readily prepared by recovering the extruded filaments or ropes by metering the absorber and polyhydroxy compound in a cold extruder as a die heated to a temperature between 175 ° F. and 450 ° F.

Preferred absorbent products as passivating aids are in foam form. The sheet-like foam product consists of about 25 to 125 parts by weight of the particulate absorbent polymer and 2 to 30 parts by weight of blowing agent relative to 100 parts by weight of the liquid polyhydroxy organic compound on the metal surface or on the silicon or other stripper coated rhool surface. Casting or coating the absorbent passivating composition and leaving the coating liquid composition at a temperature of about 175 ° F. for about 30 minutes to 24 hours or heating the coating composition to 175 ° F. to 450 ° F. for several seconds to 15 minutes is preferred. . If the absorbent product is a foam product used as a protective liner of a double walled container, the liquid immobilized absorbent composition is injected into the zone between the vessel walls and left to ambient temperature or heated to a foam sheet.

The actual amount of absorbent in the composition within the range as described above depends on the degree of absorption needed in the final environment. Therefore, in the case where the absorption is performed by the diaper and the substrate is the diaper pad, the liquid absorbent immobilizing composition, regardless of the use of the foaming agent, should contain an absorbent in an amount sufficient to impart the absorbent capacity required for the pad substrate.

The products and methods of the present invention are useful for making various absorbent articles. These products and preparations are also particularly useful for products where a high volume of absorber volume is desired, such as in worn products. These products and preparations are thus particularly useful for diapers, fecal incontinence pads, and also for menstrual bandages, bandages and the like. Both film and foam forms of the product are useful, but foam forms are more preferred. In diaper use, the absorbent product of the present invention may be used either alone or as a construct to improve the quality of existing absorbents.

In the production of diapers incorporating a film or foam product as an improvement of the liquid absorbing portion of the diaper, the composition is applied to the water-soluble liquid absorbing portion of the article, that is, the core surface, and the coated core surface is left to heat cycle or to a temperature of 175 ° F. The water-impermeable support and the water-permeable surface sheet are attached to the deformed core surface. Alternatively, a thin diaper can be prepared by coating the absorbent immobilizing composition on a conventional nonabsorbent moisture impermeable diaper base without core surface and then laminating it with a conventional moisture permeable surface sheet. Foam products are particularly suitable for use in such applications.

Those skilled in the art can produce new absorbent diapers using other technical methods. In the case of menstrual cramps, this absorbent immobilizing composition can be used on the surface of the cellulosic absorber and can be packaged by conventional methods to produce menstrual cramps with improved absorption capacity.

In the case of bandages, the absorbent composition is prepared by coating a water-soluble liquid permeable but gel impermeable material on a nonwoven fiber such as rayon or polyester fibers and inserting it into a gauze bandage. The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

Example 1-8

The absorbent compositions listed in Table A were prepared.

TABLE A

A product having the composition listed in Table A was used for substrate coating as follows to prepare an absorbent article. The products having the compositions of Examples 1, 4 and 6 consist of diaper surface sheet materials, namely (a) 1.5 to 3.0 denier rayon and contain 20 to 35% acrylate ester copolymer binder, and also square yard Nonwoven fabric sheets having a weight of about 15 to 19 g per sugar and (b) 35 to 64% of 1.5 to 3.0 denier polyester fibers, 14 to 40% of 1.5 to 3.0 denier rayon fibers and 20 to 30% of the aforementioned acrylates It is used to coat a nonwoven sheet composed of an ester copolymer binder and having a weight of about 25 to 35 g per square yard.

It was found that when the diaper was manufactured using the modified surface sheet material or when the surface sheet material was used as an insert of the disposable diaper, a diaper having excellent absorption characteristics was produced and the particulate absorbent was actually completely immobilized. Products having compositions of Examples 3 and 7 are used for substrate coated paper. The modified paper is used to make absorbent bed inserts.

The products having the compositions of Examples 5 and 8 are applied to polyethylene film and used as a support for disposable diapers. The deformed backs are laid with thin cellulose fibers forming a thin layer and then laminated with a nonwoven web to make a good absorbent diaper.

The product having the composition of Example 2 was used to coat the nonwoven rayon fabric described above and then laminated to the same material to be used as an insert for napkins and bandages. In use, each product exhibits good absorption properties due to the particulate absorbents contained in the product. In addition, the particulate absorbent material was found to be immobilized upon storage, shipment or use.

Example 10-17

The foamable compositions listed in Table B are prepared by first mixing the appropriate absorber and blowing agent together at ambient temperature, followed by the addition of a suitable polyhydroxy organic compound and mixing well.

TABLE B

In a separate operation, some of the individual compositions are treated in the following manner.

(a) Knife-coated on the peel-coating paper, (b) Knife-coated on polyethylene film, or (c) Poured until about ten-quarters of the space is filled in the space between the inner glass and the outer metal wall of the double-walled container.

When the treatment composition is left at ambient temperature to generate bubbles within a few hours, (a) the foam sheet is knife coated on the release coating paper from the composition, and (b) the foam coated film is knife coated on the polystyrene film from the composition. And (c) foam in a space close to the bottom of the double walled vessel. Except for exposing the treated sample to a temperature of about 275 ° F. for 10 seconds, this operation was repeated to yield the corresponding foam product.

When about 100 g of water is used in the foam (about 10 g size) in the individual samples described above, the foam swells while absorbing the above-mentioned amount of water practically completely immediately.

Example 18

)와 5부의 중탄산나트륨을 같이 혼합하고 또 100부의 글리세롤을 혼합해서 제조한다. 별도 조작으로 이 조성물을 기재로서 (a) 부직 셀룰로오스 직물과 (b) 폴리에틸렌필름 및 (c) 목재펄프 물질의 박층에 나이프 피복한다.The foamable composition was subjected to 80 parts of starch polyacrylate at ambient temperature.

) And 5 parts of sodium bicarbonate are mixed together and 100 parts of glycerol are mixed. In a separate operation, the composition is knife coated as a substrate on (a) a nonwoven cellulose fabric, (b) a polyethylene film and (c) a thin layer of woodpulp material.

The coated substrate is exposed to a temperature of 300 ° F. for several seconds to obtain a foam coated substrate. The foam coated substrate is then cut into sizes suitable for the absorbent article. When water is poured into an article consisting of a foam coated substrate, the free glass water is immediately removed and at the same time there is swelling of the foam.

Claims (1)

Fine water-insoluble in water having a gel capacity of 10 or more selected from polyacrylate modified polysaccharide, crosslinked synthetic polyacrylate, crosslinked carboxymethylcellulose, crosslinked poly (alkylene oxide), xanthan rubber, low-kiss rubber, guar rubber, An absorbent passivating composition comprising about 25 parts by weight to about 125 parts by weight of a water-swellable absorbent polymer and 100 parts by weight of a liquid polyhydroxy organic compound having a vicinal hydroxyl group selected from glycerol, ethylene glycol, and propylene glycol.