DE2051708A1 - Fiber products containing water-absorbent material - Google Patents

Description

Containing water-absorbent material Fiber products

The present invention relates to a new and improved method for making water-absorbent products from wood pulp-cellulose fiber sheets. The invention also relates to new and improved water-absorbent sheets, which are characterized by the presence of extenders for the water-absorbent material present in the pasers of the sheets

As discussed in U.S. Patent 3,347,236 Attempts have already been made to add powdered, water-absorbing material to a layer of cellulose fiber !! to incorporate. However, the particles showed an undesirable one Tendency for migration during manufacture, shipping, storage, or use, and attempts made were to fix the discrete particles by adhesives au, resulted in a considerable loss of surface area and of water absorption capacity

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It now became a simple, economical, and very effective one A method for anchoring the powdered material on the cellulose fibers has been found which makes it possible not only to have the powdered material in a multilayer product on its Plate, but also to hold it in a fluffy cellulosic pulp, which can subsequently be used for any desired purpose, e.g. B. the absorption of liquids, such as aqueous fluids or in particular body fluids (such as urine, menstrual fluid, eye white, blood, meat saw, etc.) should be used.

According to one aspect of the present invention, a Wood pulp-cellulose fiber sheet a mixture of wood pulp-cellulose fibers and powdered material, the one Contains substance which in contact with water (e.g. in contact with ten, one or more times, preferably 20 or more times its weight in water of 25 ° C) loses its powdery character within a very short period of time (e.g. less than 1 minute) and a soft, plastic gel forms, produced «whereby the powdered material is anchored to the cellulose fibers by surface hydration of the same.

The invention is particularly suitable for the manufacture of one-time-use baby diapers. One such The diaper can contain multiple layers, a water-absorbent layer that is used to absorb and hold the urine is suitable, and comprise a layer that comes into contact with the body, which is water-permeable and allows, that the urine passes through it and is absorbed in the absorbent layer. B. a layer of wood pulp that is about 3 »175 mm (1/8 inch) thick, or a plurality of layers. The one with the

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The layer that comes into contact with the body can have a porous, fiber-fleece-like structure, and its fiber surfaces can be hydrophobic so that the spread of aqueous liquids, like urine, is depleted in its major plane; for example, Bayon fibers can have a hydrophobic finish Find use. The one-time use (i.e. disposable) The diaper may have an outer barrier layer which is useful for the passage of urine or other aqueous liquids is impermeable. This layer can, for example, be a plastic film, κ. B. made of low density polyethylene, or a sheet made of a plastic-coated fiber material (e. B. non-woven fabric). The different layers may be interconnected in any suitable manner, e.g. B. by adhesive bonding along lines that are parallel and run adjacent to their edges

The invention can be used in a similar manner for the manufacture of bed cushions which protect the bed surface against wetting Protect, menstrual pads and tampons should be used. Table napkins, sheets, clothing, packaging materials, surgical gauze bags, towels, sutures, bandages, etc. can also be made from the products described here getting produced.

In the practice of the first embodiment of the invention, the water-absorbent ones according to the invention are used Products made by making a sheet of wood pulp cellulose fibers in the presence of a finely divided material, d. H. of a powder that, when touched, is iO times its Weight of water forms a soft, plastic gel, converted into a fluffy cellulose fiber mass and the particles are moistened to improve the particle adhesion to the fibers mentioned. The conversion of the arc can be done by

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chipping, tearing or otherwise severing the fibers can be accomplished from the arch to form the flaky cash register.

A suitable method for incorporating the powdered cash register into the cellulose fiber)! is that the powder over a relatively dense sheet of wood pulp-cellulose fibers (e.g. the relatively hard and brittle sheet, which is, for example, about 3.175 nm thick, and in what form cellulose pulp is usually supplied is) and then the mixture is passed into a device of known type which tears the tight arch or macerating and making it fluffy, or that the powder is added to the wood pulp fibers in the caging device, with the water vapor entering the device or into the resulting flaky cash register is blown · The flaky The cash register can then be fed to a drying apparatus to reduce its moisture content.

A dense sheet of cellulose may appear on its surface areas roughened or mechanically flaked, and then the powder can be spread over the roughened or flaked surface. The product obtained can be used before, during or after further maceration and flaking of the be moistened throughout the arch.

The production of the bond by moistening can also be effected by using the normal moisture content of the fibers (naturally occurring cellulose fibers ^ can have a "moisture absorption" in the region of 7 % ) without water vapor being blown in, or the mixture of powder and Cellulose fiber is heated in a closed 0 to drive off some of the moisture on the surfaces of the powder during the heat treatment or when the mixture is cooled

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Connecting the powder with the pasem has a supportive effect

The amount of water-absorbent, gel-forming material in the final product usually ranges from about 3 to 35 % based on the weight of the cellulosic fiber and preferably from about 5 or 10% to about 20 or 30%. The exact amount depends on the particular use and total amount of cellulosic fibers used in the finished product. For example, in the case of a diaper containing 34 g (1 x 2 ounces) of cellulose, the gelling material may be present in an amount of, for example, about 1.4, 2.8, 5-6 or 8.5 g.

Water-absorbent materials that can be used »are disclosed in patent application P 19 44 550.2, in which also Methods for humidification etc. are described · In general, the water-absorbent material is a natural one or synthetic rubber or bars. This group includes polysaccharides and their derivatives such as guar gum and water-swellable cellulose derivatives, never high molecular weight cellulose ethers (such as sodium carboxymethyl cellulose) as well as fully synthetic polymers. Mixtures of water-absorbing substances, such as mixtures (which contain, for example, approximately the same proportions of the substances) of sodium carboxymethyl cellulose with water-soluble hydroxyethyl cellulose or with Bydroxypropylcellulose or with gelatine (e.g. gelatine A), are usable »It is desirable that the substances are harmless and harmless to the body of the person using the absorbent products are used, are inert and that they are practically stable to urine (the pH of which is often in the weakly acidic range, *. B. in the factuality of 6, is) · Components can be added to increase the tendency to gel · For example, aluminum acetate («. Β · can be added in amounts of

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5 or 10%, based on the weight of the sodium carbonate (ethyl cellulose) can be added.

The second embodiment of the invention relates to the use of an extender together with the powdery material, d. H. with the * water-absorbent fabric. The extender can also be water absorbent and is preferred Silica or a silicate. The use of the extender enables better mixing of the water-absorbent Particles and the cellulose fiber and also a better flow of the powder during processing. Additionally is achieved through the use of extenders, which distribute the water »absorbent substance more evenly in the fiber mass, achieved greater uniformity of the product obtained. Preferred extenders are fine types of silica, such as Cab-O-Sil, hydrous aluminum silicates such as magnesium aluminum silicate, e.g. B. Attapulguston products and the like. Starches and similar such substances can also can be used as an extender. Bolt by-products such as lignin and its derivatives can also be used.

The use of extenders makes the according to the invention The method as well as the method described in the aforementioned patent application has been significantly improved.

The following examples are provided for further illustration brought this invention. In these examples, the Pressures, unless otherwise stated, atmospheres · All proportions are in this description, unless otherwise specified given, based on weight.

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JFS 8601 example 1

2 ropes of guar gum powder ("Jaguar TA") are mixed at room temperature with 2 parts of sodium carboxymethyl cellulose powder (highly viscous type, Hercules CHC? H4 with a degree of substitution of 0.7 and a viscosity, determined as a 1 # solution, of approx 2500 to 4500 Centipoises at 25 ° C), 1.5 parts powdered, insoluble, water-containing aluminum silicate (Engelhard ASP 200 with an average particle size of 0.44 microns, the particles being flat, thin platelets) and 0.5 part of alkylnaphthalene sulfonate wetting agent ("Petro AG |

fines "). To 1.76 parts of this mixture add a small amount of a perfume (0.02 part) and 0.025 Parts of a bactericidal (Sow Cinaryl 200, a water-soluble quaternary ammonium compound, namely 1- (3-chloroallyl) -3,5,7-triaza-1,1-azoniaadamantane chloride, which is able to give off 6 moles of formaldehyde per mole of the compound) . The dry mixture obtained, which is a free-flowing powder, is reduced to a weight ratio of 1: 5 About 3 * 175 mm thick wood pulp-cellulose fiber sheet is scattered, and the sheet is known in a macerator Type of construction (as it is used in the wood pulp industry) introduced while saturated water vapor is introduced into the mass «The water vapor treatment is ended while" the flaky fiber mass still feels practically dry. The mass can then be subjected to a drying process.

The dry product obtained is practically as flaky as the mass obtained when the fibers are more similar Veise moved without the particles and without vapor treatment will. The two masses of fiber look practically the same when touched with the naked eye have practically the same grip and can be easily pulled apart with your fingers.

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nis proves to be very prone to urination. For example, if you apply urine to the product, between the Allow applications a few minutes to pass (and squeeze the wet product with a spoon to get the effect mimicking the movement of the baby wrapped in a diaper containing the product) and then the product squeezed firmly between the fingers, no urine can be squeezed out of the moist product. (In addition, there are no urine odor to be recognized even after standing for hours.) If, on the contrary, the same experiment with the untreated pulp (a widespread, commercial, single-use diaper) is carried out see slightly squeezing liquid urine

Example 2

Example 1 is repeated, the 2 parts of carboxymethyl cellulose being omitted and M parts of the guar gum ε being used instead. Excellent results are obtained.

In experiments used to determine urine retention of guar gum and carboxymethyl cellulose alone compared with that of mixtures of guar gum and the carboxymethyl cellulose were carried out, it was found that the mixture surprisingly within a given period of time (e.g. 10 minutes long contact while is stirred) results in a slightly more viscous gel.

Very good results are also obtained with smaller amounts of parts of the powdered mixture, e.g. B. with 5 or 10 #, related on the weight of the pulp.

The mass preferably contains a stimulant and still preferably

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In addition, a sulphate or sulphonate stimulant »the one on a sulfate or sulfonate group linked, hydrophobic portion has »z. B. alkyl naphthalene sulfonates (e.g. sodium isopropyl naphthalene sulfonate), Sodium Lauryl Sulphate »Bioctyl Sodium Sulphosuccinate etc. Among other desirable effects, the wetting agent also shows that it prevents urine penetration into the product and that it also appears to result in more rapid gel formation. The mass can also be a bactericide contain. It has been found that the addition of such a material after the formation of the undesirable odor ammoniacal urine of the diaper saturated with urine when standing »- let strong inhibits.

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Claims (1)

JFS 8601 October 81, 1970 Pat does not respond Process for the manufacture of water-absorbent products, characterized in that in the following stages (a) a sheet of wood pulp-cellulose fibers in the presence of a finely divided material which on contact with ten times its weight in water forms a soft, plastic gel into a flaky cellulose faoeimaeee converts and (b) the particles are moistened to improve the adhesion of the particles to the fibers mentioned 2. The method according to claim 1, characterized in that the finely divided material is applied to the Bow. 3 · The method according to claim 1, characterized in that the finely divided material during the conversion brings up. 4. The method according to any one of claims 1 to 5, characterized in that the moistening is carried out with water vapor. 5. The method according to claim 4, characterized in that the steam is added to the mixture during the conversion step. 6. Procedure according to. Claim 4, characterized in that • the steam is added to the mixture after the conversion. - 10 - 109818/2120 Ji ¹ S 8601 7. Method according to one of Claims 1 to 6, characterized in that that the surface of the arc β is mechanically roughened or made flaky before the conversion. 8. The method according to any one of claims 1 to 7 «characterized in that that the product obtained is dried to reduce the moisture content. 9 · Method according to one of claims 1 to 8 »characterized in that that two layers are formed from the product obtained, which are then applied by applying pressure compacted to reduce the thickness. 10. The method according to any one of claims 1 to 9 «characterized in that that you can get the said material in the form of a Mixture with an extender added. 11. The method according to claim 10, characterized in that the extender is silica or a silicate. 12. The method according to any one of claims 1 to 11, characterized in that that said material is a polysaccharide gum. 13 * Method according to one of claims 1 to 11, characterized in that that said material is guar gum and / or carboxymethyl cellulose. Absorbent sheet, containing an adhesive mixture of substantial thickness of water-insoluble fibers, in particular cellulose fibers, and (particles of a material, which forms a plastic gel on contact with 10 times its weight in water, the aforementioned Particles to improve their adhesion to the named - 11 - 109818/2120 JPS 8601 Fibers have been moistened and used as an extender for the mentioned material silica or a silicate 15 · sheet according to claim 14 ·, characterized in that the Extender is a hydrous aluminum silicate. 16. Sheet according to claim 15 »characterized in that the Extender is magnesium aluminum silicate. 17 · Sheet according to one of Claims 14 to 16, characterized in that that the material is a polysaccharide gum, in particular gua.r gum and / or carboymethyl cellulose. - 12 - 109818/2120