DE2008614A1 - Absorbent non-woven fabric - Google Patents

Description

PATENT ADVOCATE DR. HANS-GUNTHER EGGERT, DIPLOMA CHEMIST

5 KOLN-LINDENTHAL PETER-KINTGEN-STRASSE 2

Cologne, February 23. 1970 Ax / Stü / 61

Johnson & Johnson, 5ol George Street, New Brunswick, New Jersey, USA ______ ^ _

Absorbent non-woven fabric

The invention relates to absorbent products that have a have very high absorbency and low adhesiveness and can be used as surgical swabs and wound dressings suitable.

Swabs usually consist of multiple layers of gauze or, more recently, one or more layers a nonwoven fabric. The usual gauze swabs are relatively expensive to manufacture and tend to be for bonding to wounds if they are not modified by further treatment.

Nonwovens are used as a substitute for gauze swabs. They switch the disadvantages of the known world-wide Swabs off, however, it has been found that in certain cases, nonwovens cling to each other during steam sterilization stick together and tend to discolour as a result of sterilization.

The invention relates to a fabric made of nonwovens new swab that avoids the disadvantages of the known swabs made of gauze and at the same time has all the advantages of the known nonwovens.

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Furthermore, the product according to the invention has its own desirable properties, which are detailed below is received.

The absorbent nonwoven material according to the invention consists of at least one layer of a nonwoven fabric with a Binder has been treated, which consists of a mixture of a) a water-insoluble, high molecular weight alcohol, which can make a high molecular weight carboxylic acid insoluble, b) a high molecular weight carboxylic acid which is insoluble in water Polycarboxylic acid and c) an acrylic polymer.

It has been found that the products according to the invention have poor adherence to wounds while Do not stick together during sterilization, have a high absorbency and are more comfortable and viable are a wound. In addition, the products according to the invention are economical to manufacture.

It is believed that the improved properties of the products according to the invention are due to the new treatment agent used can be attributed to the fact that the products have no undesirable sticking, no discoloration and show similar properties. The high molecular weight polycarboxylic acid and the high molecular weight alcohol are chosen so that they complement one another in such a way that each component, when combined, forms an insoluble one Caused by means or mixture.

Polyvinyl alcohol is preferred as the alcohol because it is readily available and inexpensive. For the same reasons Polyacrylic acid is preferred as the polycarboxylic acid. However, other acids and alcohols other than those mentioned above can be used have required properties can be used for the purposes of the invention.

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The other component of the mixture, the acrylic polymer, can be any suitable polymer which, when mixed with the other components, forms a mixture that is not curable or rough. Typical are polymers of butyl acrylate, ethyl acrylate and their mixtures.

The components used in the treatment agent according to the invention can be used in any suitable manner Formation of the treatment agent are mixed. Preferably the alcohol and the polycarboxylic acid come first mixed, whereupon the resulting mixture is mixed with the acrylate polymer.

The specific mixture of the three ingredients obtained is believed to be some kind of reaction product forms whose nature or equilibrium composition, based on the converted components, not yet is fully resolved.

It is not intended to be bound by any particular theory, but it is believed that the reaction product may be an esterification product, that with the methylol groups of the crosslinking acrylate polymer is partially implemented.

The most varied types of materials are suitable for producing the nonwoven. Typical for this Materials are viscose rayon with a denier of less than 4.5 denier, cellulose acetate with a titer below 4.5 denier, cotton (bleached wadding), polyester with Titers below 4.5 denier and polypropylene with titers below 4.5 den. Of course, other materials can also be used.

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It is preferred but not essential that the nonwoven fabric used for the purposes of the invention is stabilized against a detrimental change by a suitable known stabilizer is incorporated during its preparation. A typical stabilizer is sodium metabisulfite, which can be used in an amount of about 0.5 to 1.0 % .

Another preferred, but not indispensable feature of the invention is the addition of a surfactant to the non-woven fabric to increase the consumption rate. Wetting agents of this type are known. An example is the dioctyl sodium sulfosuccinate which is commercially available under the name "Deceresol OT" or "Triton GR-5". This optionally wetting agents used may be present in an amount of about 0.5 to 1 wt.%.

The nonwoven fabric can be made by known methods such as the method of Canadian Patent 653,278 will be and be trained.

Preferably, a nonwoven fabric is used which has a perforation pattern that resembles a gauze. Such a pattern allows liquids and / or air to pass through the products more easily, which increases the suitability as a swab. However, nonwovens with other patterns can also be used with which the purposes of the invention are achieved.

The amount of binder which is incorporated into the nonwoven fabrics to impart the desired properties may be different. It is expediently 5 to 30 %, preferably 10 to 15 %, based on the dry solids content. However, these numbers can be used in

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Vary depending on the particular end product desired.

The binder iaifc can be applied by any suitable means according to conventional methods. For example, the nonwoven fabric can be passed through a bath of the binding agent or the binding agent can be printed on using the gravure printing process, for example. When printing, it is not necessary to print the entire nonwoven fabric. It is sufficient to only print a certain percentage, for example 35 % or less of the surface of the fabric.

A mixture of three components, namely one, is particularly preferred for treating the fiber webs crosslinking acrylic resin emulsion, e.g. the product of the trade name "Rhoplex - ΉΑ-8", a solution of a Polyvinyl alcohol and a solution of a polyacrylic acid. It has been shown that these mixtures are the best Results are obtained when using 20 parts by weight of acrylic resin emulsion (calculated as pesticides), 1.6 parts by weight of polyvinyl alcohol (calculated as pesticides) and 0.53 Contains parts by weight of polyacrylic acid pesticides.

The figure shows a preferred range of the preferred three-component mixture. The point A denotes a component, the acrylic polymer, the point B the polyvinyl alcohol and the point C the acrylic acid component. Points A, B and C each represent a mean that consists of 100% by weight of the individual components,

Preferred copolymers of acrylates for the purposes of the invention are, for example, those of ethyl acrylate, Butyl acrylate and methylol acrylamide, which are produced by the action of heat and catalysts or by

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effect of heat alone are networked.

The preferred range of amounts of the constituents of the preferred mixture is shown by the hatched area within the triangle with the tips A ', B * and C ¹ . In this area, A represents a mixture that is about 93.8 wt /? Acrylic polymer, 4.7% by weight polyvinyl alcohol and 1.5 % by weight acrylic acid. At point B ^1, the mixture consists of about 48 wt. Si acrylic polymer, 42 wt.% Polyvinyl alcohol and 10 wt% of acrylic acid.. At point C ^f 34 wt the mixture consists of about 48 wt.% Acrylic polymer.% Polyvinyl alcohol and 18 Gew.X acrylic acid.

The surgical sponges and swabs according to the invention can contain absorbent cores or consist essentially of one or more layers of a fiber fleece folded in the desired catfish. If the swab is to be provided with a core made of absorbent material, such as fluffy wood pulp or mixtures of wood pulp fibers, for example rayon fibers, these products can be produced by conventional methods. Likewise, the folding of the nonwoven fabric to form two or more layers of the material can be carried out by known methods.

The treatment of the products for the application of the binding agent to the fiber fleece takes place during the manufacture of the fiber fleece.

example 1

A fiber fleece with a perforation pattern in the manner of foramina and a weight per unit area of about 15 »5 g / m 2 was treated with a mixture of the following composition:

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Acrylic polymer (Rhoplex - ΉΑ-8). 93.8% by weight polyvinyl alcohol 4.7% by weight.

Acrylic acid (Carbopol 93 ¹ O 1.5% by weight .

This treating agent was prepared as follows: the polyvinyl alcohol solution and the acrylic acid solution were mixed in the required proportions. This mixture was then stirred into the emulsion of the acrylic polymer added.

To treat the nonwoven fabric, the mixture was applied by gravure printing so that the nonwoven fabric as a whole approximately 16% by weight of dry solids were picked up. Of the treated nonwoven fabric was then cut into blanks and folded to form swabs.

Samples of the swabs were ^{sterilized with live steam at 124 °} C. for 20 minutes. After 20 minutes, the samples were measured and examined for sticking and discoloration. It was found that there was virtually no undesirable sticking and that the swabs had a \ + b value of less than 8. In comparison to samples which had been prepared using other known binders and which had been sterilized with steam, it was found that these known samples were glued and had a '+ b value of more than 11. The tests for determining the discoloration are known. A value of less than 8 represents a very good product, while a value of more than 11 means severe discoloration. It can thus be seen that the products according to the invention have improved and superior properties compared to the known products.

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- 8 Example 2

Swabs were prepared in the manner described in Example 1, except that a stabilizer used in this case in an amount of about 0.5 wt.% Of the treatment mixture. In this case too, the products were sterilized in the manner described. The product showed the same properties as the product prepared according to Example 1.

Example 3

Swabs according to the invention were made in the manner described in Example 2. They consisted of a layer of a nonwoven fabric which had a weight of about 27.1 g / m ² . The nonwoven fabric was the product of the trade name "Keybak". The swabs were treated with the components mentioned in Example 2. Two different swabs were made, one from 8 plies measuring 10.2 cm 10.2 cm and one from 6 plies measuring 10.2 cm 10.2 cm.

Furthermore, common swabs from several layers of one j Gauze that has been folded into: 10.2 cm products j χ 10.2 cm.

The two products according to the invention and the usual gauze swabs were then used in several series of tests to determine their adherence to wounds. These tests showed that the products according to the invention are practically not adhered to wounds, while the usual gauze swabs adhered to the wound in almost all cases.

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Claims (18)

Claims 1. Absorbent nonwovens that have been treated with an agent which are composed of a mixture of (a) a mass-insoluble, high molecular weight alcohol which is able to make a high molecular weight carboxylic acid insoluble, (b) one in water insoluble high molecular weight polycarboxylic acid and (c) a crosslinking acrylic polymers. 2. Absorbent product that has improved resistance to discoloration and has undesired sticking during sterilization and consists of at least one layer of a nonwoven fabric and has been treated with a mixture consisting of a high molecular weight polycarboxylic acid, a polyvinyl alcohol and an acrylic acid polymer. j5. Absorbent product that has improved resistance to discoloration and unwanted sticking during sterilization and consists of at least one layer of a nonwoven fabric which has been treated with a mixture of polyvinyl alcohol, polyacrylic acid and an acrylic polymer from the group of ethyl acrylate-methylolacrylamide copolymers, butyl acrylate -Methylolacrylamide copolymers and copolymers of ethyl and butyl acrylate with crosslinking groups, the amounts of the components of the mixture are coordinated so that they ^{fall into the closed area A 1} , B ¹ , C ¹ in the accompanying diagram. 4. Product according to claim 1 to J5 * characterized in that the nonwoven fabric has a stabilizer to prevent a contains adverse change. 5. Product according to claim 1 to J, characterized in that the nonwoven contains a wetting agent. 6. Product according to claim 3 *, characterized in that the treatment agent prior to the treatment of the absorbent product, 009836/2256 - ίο - e.g. a swab, 2o parts by weight of the crosslinking Acrylic polymer emulsion (calculated as pesticides), 1.6 parts by weight Contains polyvinyl alcohol solids and 0.53 parts by weight polyacrylic acid solids. 7. Product according to claim 5 *, characterized in that the treatment agent contains about 93j8 # of the acrylic polymer, 4.7 wt. # Polyvinyl alcohol and 1.5 wt. % Acrylic acid prior to the treatment of the absorbent product. 8. Product according to claim 5> characterized in that the treatment agent before the treatment of the absorbent product or swab from about 48 # acrylic polymer, 42 wt. % Polyvinyl alcohol and Io wt. # Acrylic acid consists. 9. Product according to claim 5> characterized in * that the treatment agent prior to treatment of eaugfahlgen product or swab from about 48 wt.% Acrylic polymer,} 4 wt. ^ Polyvinyl alcohol and 13 wt.% Of acrylic acid exists 10. Product according to claim 1 to 9, containing sodium metabisulphite as a stabilizer. 11. Mixture of substances that can be used to improve properties suitable for absorbent products, consisting of a mixture of (a) a water-insoluble, high molecular weight Alcohol capable of making a high molecular weight carboxylic acid insoluble, (b) a water-insoluble, high molecular weight polycarboxylic acid and (c) an acrylic polymer. 12. Mixture of substances that can be used to improve properties suitable for absorbent products, consisting of a mixture of high molecular weight polycarboxylic acid with a polyvinyl alcohol and an acrylic acid polymer ^ 13. Mixture of substances designed to improve properties suitable for absorbent products, containing a mixture of a crosslinking ethyl acrylate homopolymer, a butyl 009836/2258 20086H acrylathoraopolyraeren and of crosslinking copoiymeren of ethyl acrylate and butyl acrylate, the amounts of the components of the mixture of substances are coordinated so that they are in the closed area A ^! , B ¹ , C ¹ fall in the graph. 14. Stoffgeraisch according to claim 11, 12 or 15, containing a Stabilizer. 15 · Mixture of substances according to claim 11, 12 or IJ, containing sodium metabisulphite as a stabilizer. l6. Mixture of substances according to claim 11, 12 or 13, containing a Wetting agents. 17 · Mixture of substances aimed at improving the properties of Suggestable products, containing a mixture of 2o Parts by weight of acrylic polymer emulsion (calculated as pesticides), 1.6 parts by weight of polyvinyl alcohol solids and 0.53 parts by weight Polyacrylic acid solids. 18. mixture which is suitable for improving the properties of absorbent products containing a mixture of 93.8 £ Aorylpolymerisat, 4.7 wt.% Polyvinyl alcohol and 1.5 wt. £ acrylic acid. 19 * mixture of substances suitable for improving the properties of absorbent products containing a mixture of wt. Aorylpolymerisat Ji, 42 wt. # £ polyvinyl alcohol and acrylic acid. 2o. Mixture, is extending augfähigen to improve the properties ¥ ön © products containing a mixture of h% Q e *% Aerylpolymerisat. J4% by weight of polyvinyl alcohol and 13% by weight of acrylic acid. 2.1 »Process for improving the durability of nonwovens unwanted sticking and discolouration, thus identifiable 009836 / 2258- ^; ι i, .ü -... 20086 H. zeiclinet that t: ian the fiber fleece with the mixture of substances according to Claim 11, 12 or IJ dealt with. 009836/2258