DE2352218A1 - PRESSED CELLULOSE REGENERAT SPONGE - Google Patents

Description

Pressed regenerated cellulose sponge

The invention relates to sponges made from regenerated cellulose, especially on those artificial sponges that are suitable for surgical! Works and for local wound dressings, as a means for feminine hygiene, as well as for technical purposes, such as filters and ! Desiccants are suitable and their production.

It is known that regenerated cellulose sponges are made from a mixture of viscose, reinforcing fibers made of e.g. linen, jute, cotton or regenerated cellulose fibers and a pore-forming material,

usually crystal: sat of Naf * ¹ i umsulfat-Dekahydrat or other; Alkali salts with a high water of crystallization content, such as sodium acetate trihydrate, sodium carbonate decahydrate, trisodium phosphate twelve hydrate, disodium phosphate twelve hydrate or potassium sodium tardrate tetrahydrate.

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Γ This gives a viscous solution of viscose with 5 - 8% cellulose, 6 - 1007th fibers, based on cellulose as a reinforcing agent »and 900 - 2500% of the inorganic, pore-forming salt, based on cellulose. The final pore size depends on the size of the pore-forming inorganic crystal ■ _v || salt off. The mixture is then brought into the desired shape, eg shaped by means of molding nozzles, and the cellulose coagulates and regenerates. After regeneration, the shaped mass is subjected to a washing process with water to remove the soluble salt J and other components, then desulphurized, bleached and usually finally with a solution of a plasticizer such as glycerine or propylene glycol treated. Sine 1 '; the same kind of manufacturing method for artificial sponges is allowed as so

3 are apart from a continuous in ^r s detailed description of such Horstellungsprozesse; are considered known as

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As for the sponges, there are currently surgical ones Purposes various products for special surgical indications, to aspirate blood and body fluids. One example means commonly used in eye surgery a polyurethane foam provides a special shape a spear-shaped piece from a foam sheet. Its main disadvantage is that it is only a small Degree of absorption of body fluids and blood, i.e. has a relatively low fluid absorbency. A

40931Θ / 10Θ8

The advantage, however, is' that such a cunning is use is relatively free of fine hair fibers on his Surfaces.

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j Another kind of so-called surgical sponge from the usual one ! ZeIluloser © generatform is apparently manufactured by careful pockets of cellular regenerated sponge material up to jj Removal of all soluble components, including Plasticizers, and then by compressing the Schwsmes after the Drying »after which a cutting to the desired shape and Size, e.g. to a narrow, spear-shaped, or triangular one j! cutting is made. This type of spear consists of ι! 'a head piece made of sponge in a pointed triangular fora, which is about

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1Θ is now long and about 9 mm wide at the base and becomes a very fine tip ends at a thickness of about 1.6 mm and a handle made of plastic or on the sponge Wood is attached to the base. These kind of sponges absorb Liquids including blood quickly and also have a remarkably higher absorbency than does the Polyurethane sponges is the case, but the main disadvantage of using this type of sponge is that it does not fine fiber fragments arise during the cutting process and then ; when wetting the sponges run along the top of the

j spongy fine fiber particles appear. Then become such * » Schväira * »in eye or ear surgery or for anoere chrur» gical or other medical purposes »advertise

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these partly very fine particles exposed by fibrils, sit in place of the sponge and then unwanted foreign material (cellulose), the not even detectable with the naked eye is fixed.

In der'US Patent 3,018,192 of 23 ¹ .1962 a method for increasing the resistance of sponges from CEI] is uloseregenerat against bacteria and fungi, to be precise for technical applications such as Avowäsche. According to this process, the regenerated cellulose sponge is treated with "an aqueous solution of carboxymethyl cellulose or an alkali salt thereof and then with a solution of a quaternary ammonium compound, the"> e ammonium compound apparently reacting with the carboxymethyl cellulose to form a reaction product " not dissolved by water and as a result remains in the sponge for the duration of its use

! 'quarter clock ammonium verb indurv) η solution foehando.ln and then with

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j'der CarboyymethylTelluloiRKJTunT. In the only ones in the PS entj ^j ha \ th '' n ΠβίηρίβΙϋη vvr * \ nn <U <"i ^ ichw imino treated with 1 wt .- #

| Matriuincarboxym «» thyl / <? Ll uhs ^ oHJr.imrjen and 1 G <* v. ~% Solution of ί quart er nary ammonium Vorbinrlun-i. Even these treatments have the result of preventing the build-up of skin hairs on the cut surfaces of the sponges.

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dues. are that, compared to the untreated sponge such ER _S eugnisse not very effective for the purposes described.

The invention is then based first of all on the object of creating products and a method for treating regenerated cellulose sponge materials, according to which the formation of fibrils during moistening is reduced and / or the absorption rate ^{1 of} the sponges for liquids is increased and the liquid absorption capacity of the sponges treated thereafter is improved.

A further aim of the invention is to provide one Sponge product, the particularly low, even practically negligible fibrillation compared to that of polyurethane; and other synthetic resin foams and also one of the properties particularly sinew: lcr absorption with improved Fluid absorption.

The invention is based on the finding that regenerated cellulose sponges with improved properties for the purposes mentioned above ■ Have, are obtained by saturating a material made of spongy regenerated cellulose by immersion in a Solution or dispersion of a water-soluble or water-dispersible Polymer of higher r: o. <? kui ir weight of hydrophilic Property and with the Fahigkoj '· /.u- Fi lmbildunn, being the Solution of 0.05 to 0.25% by weight; i cics jo.io ^ .ton or dir.per «iiert

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Containing polymers, and by drying the thus impregnated sponge and then compressing the dried sponge.

Further objects and advantages due to the invention are as follows Description in conjunction with the drawing - which is a graphic explanation of the critical relationships between Liquid absorption properties of the slurries and the Concentration of polymer in the impregnation solutions or Disper-I represents sion mass - to be taken.

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The sponges according to the present invention can be produced from commercially available types of regenerated cellulose sponges, as they are supplied either in expanded orcrr in pressed form. Preferably, the Zellulosereaeneratschwanun of 6 12 wt includes -.% 'Fibers. The average pore sizes of the dry, expanded sponge can vary from about 0.5 mm up to about 3.5 mm, preferably between about 0.5 mm to 1.5 mm, commonly referred to as "mean pore size ¹ " and this preferably for general health , in particular for surgical purposes.

The or the like in plates. Delivered raw pieces are made with water soaked and then washed thoroughly with water to make all soluble To remove constituents, such as salts, the b «? I, heror Manufacture were used and any plasticizer, ier ·. · -V <a could be present. Do this thorough washing out of the excess water by expressing it or by living it through ** d ^ s

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saturated sponge eliminated by squeegee rollers. The remaining damp sponge is then dipped in a solution or dispersion of a water-soluble or dispersible in water saturated high molecular weight film-forming hydrophilic polymer. This polymer can consist of carboxymethyl cellulose or an alkali salt thereof, such as sodium carboxymethyl cellulose, Hydroxyethy1 cellulose, hydroxypropylmethyl cellulose

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Llose, methyl cellulose, regenerated cellulose from solutions of cellulose xanthate and copper ammonia cellulose, caragen, starch, gelatin

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tine, collagen, microcrystalline collagen, or polyvinyl alcohol the thickener known under the trade name "Carbopol" j [for cosmetic purposes, textile auxiliaries, paints and the like ..

i Microcrystalline collagen is described in U.S. Patent 3,628,974

from 21.12.1971 and stei »; ! a water-insoluble, ionizable partial acid salt (preferably a hydrogen chloride salt) of ί collagen is, with a bound, ionizable acid content, ί:. of about 50 to 90% of the stoichiometrically bonded Säuregehal- \ tes, at least 10 weight '% of the Partialsalzes have thereby one

Particle size under a micron. The solution or dispersion can, I from 0.005 to 0.250% by weight of the dissolved or dispersed poly ! mers, preferably 0.010 to 0.030% for medical π and surgical purposes.

The excess liquid is made up of the saturated piece of cockatoo removed e.g. by pressing and the piece then dried, e.g. by oven drying at about 75 ° C for 1.5 hours. the

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Special drying conditions are selected so that the desired bond is obtained between the film-forming polymer and the base-forming sponge material. The drying should be sufficient for the dried sponge to have no more than 0.5% volatile liquid. The dry one. Sponge should contain between 0.15 to 5% by weight of film-forming polymer and, preferably for medical and surgical purposes, the film-forming content should be between 0.4 and 1.25! % By weight. The dried and uncompressed, treated sponge has a bulk density between about 40 and 72 kg / cm.

Because of its natural nature, the regenerated cellulose sponge absorbs moisture from the atmosphere. In order to improve the dimensional stability of the pressed impregnated sponge, the dried sponge is post-treated before compression. Usually, such a dressing can be achieved under normal atmospheric conditions by keeping it at a temperature of about 23 ° C and a relative humidity of about Can absorb 50% atmospheric moisture. Of course , other temperatures and conditions can also be used. It has been shown that, provided the sponge is less than about

_; Contains 5% moisture at the time of final compression · its stability is poor and then the sponge absorbs moisture and swells. The sponge is therefore allowed to absorb at least 6% moisture, preferably 7-12% before

ner compression. After the sponge has absorbed an equilibrium amount of moisture, 3T is compressed, for example at a pressure of about 1400 to 1680 kg / cm using direct compression, such as with a carver press. Of the; Compressed sponge has a bulk density between 320 and 800 kg / cbm for use in surgical types, ie a bulk density of about 4.5 to 20 times that of the original sponge. For other purposes, for example for tampons, tobacco smoke filters or absorbent inserts for dental treatment, the bulk density can be as low as 112 kg / cbm; In other words, the compressed sponge should have a bulk density of about 1.5 times that of the initial sponge. The product .can! therefore have a bulk density of from about "M2 kg / m to 800 kg /; n (1.5 - 20 times that of the initially specified sponge product, depending on the intended use of the product to be manufactured.

For the purpose of further explanation, the following examples are given:

Example I

A commercially available yellow, fine-pored regenerated cellulose sponge (Pore size approximately 0.2mm to 1.2mm) as obtained from the dealer, was thoroughly washed in water to remove any to remove soluble components. The sponge, which was then soaked up again, was then placed between strips of aluminum

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The film was placed and passed through between the rubber rollers of a Handyringer with its set of springs set to 7 »5 cm in order to remove the excess water. The sponge was then dried in the oven at 75 C for 90 minutes.

After removing the dry sludge from the furnace in an expanded form of about 7.5 now in thickness it was between the jaws of a vice to a thickness of about 1.2 now compressed.

Example I I \

Commercially available white cellulose egonerate sponge with a mint

Larger pore size (pores approximately 0.5 mm to 3.5 mm) as available in highly compressed form from the dealer, became as in Example I treated. The dry sponge of this example was approximately 15 mm thick and was compressed to about

λ, 2 mm.

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Example IV

A commercially available white cellulose sponge was used, as in Example III, was soaked with water, washed with water to remove soluble components and placed between cellulose sheets, by rubber rollers, wife in Example I described, directed to remove excess water. The then still moist sponge was then in a dispersion of microcrystalline collagen (partial salt of collagen with approximately 84% of the theoretical stoichiometric amount of HCL) -

the dispersion contained 0.01% by weight of microcrystalline collagen, brought in. The test piece was then made from the dispersion taken out, placed between aluminum sheets and rubber rollers cranked to remove excess water and then dried in the oven at 75 ° C for 90 minutes. Taken out of the oven the dry, impregnated sponge was compressed to a thickness of approximately 1.2 mm.

Example V

Commercial white regenerated cellulose sponge, as shown in the example III, was treated in the same way, using a gelatin solution with 0.01 instead of a microcrystalline collagen dispersion % Gelatin by weight used.

Example Vl I am a commercial white cellulose generator Schwassa vurd® vi «. in Example III dealt with replacing the microcrystalline Collagen dispersion with a polyvinyl alcohol solution

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Salary of

0.01 wt .- * polyvinyl alcohol.

Example VII

Example III was repeated, replacing the microcrystalline dispersion with a hydropropylmethyl cellulose solution a content of 0.01% by weight of hydroxypropylmethyl cellulose.

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! Example viii

Example III was repeated replacing the microcrystalline collagen dispersion by a starch solution with a gel

hold art 0.01 wt .- * starch «.

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; This example consisted of a commercially available surgical, spear-shaped polyurethane sponge.

X and XI

ele X and XI

Pattern b «o ^ tand« n also available for sale pike-shaped for surgical use made from regenerated cellulose.

Spieil-shaped or dr "l © cktrj"! Kusitei: · Cut to size from the products of everybody · Examples I to Example VIII, where di # 3pieao about ifii mm 1 / ui * j, at the base about 9 mm long and they are closed of a spider were young and about 1.2 mm thick. On average, the samples weighed about 40 mg. The specimens of all of these aforementioned examples were

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Table 1

example Fiber distributors time to
saturation
(lake.)
water Blood Weight gain in%
Water blood 2150 I. 3.0 0.9 3.3 1960 1971 II 1.8 1 .4 3.6 1701 2648 III 1.3 0.8 1 .1 2470 2975 IV 0.5 0.9 1.3 2735 2798 V 0.5 0.F 1.5 2510 2962 VI 0.5 0.7 1 .6 2668 2664 VII 0.5 0.9 I.B 2930 2623 VIII 0.4 1 . 1 1 -4 2558 1971 IX 0.5 10.6 10.1 1716 1723 X 7.0 ι;. 2.6 2305 2889 XI 7.25 3.2 2485

Example XII

To the effect of the concentration of film-forming polymer to clarify in the impregnation solution or dispersion, Example IV was repeated, with dispersions with a content of 0.01% microcrystalline collagen dispersion now being used 0.50%, 0.25%. 0.05%, 0.01% and 0.005% by weight of microcrystalline collagen dispersions (MCC) were used. The examples of Skewers were examined under the microscope and the time to saturation and weight gain of the samples were noted and listed in Table 2.

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Table 2 Time to sow
treatment (see.)
Water blood 71.4 Court sgevinn
in %
Water blood 1741 Impregnation
Di sp er .; ion
(% MCC) fiber
ver te 33.7 25.6 1445 2640 0.50 0.4 6.4 1.3 2519 2920 0.25 0.4 1 .2 1.3 2719 2975 0.05 0.5 0.9 1.9 2735 2976 0.01 0.5 0.8 2585 0.005 1.1

In order to show the decisive importance of the concentration of the film-forming polymeric solution used to saturate the sludge, the values for the rate of absorption, the court sample values for this mixture, depending on the use of the various concentrations in the dispersions, can be seen graphically from the drawing . From curves 1 and 2 there, one can see that there, before the concentration of the impregnating solution exceeds about 0.05X, the rate of absorption decreases rapidly and, before the concentration of the impregnating solution exceeds 0.25 *, the percentage dish sgevinn or the absorption capacity the sponges decreases rapidly, as can be seen from curves 3 and 4.

Samples of sponges impregnated with dispersions, with 0.01%, 0.02% and 0.05% by weight of microcrystalline collagen were analytical is checked for its nitrogen content and the collagen content is calculated from this. The sponges each contained 0.4 *. 1.0% and

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ι, 4 # weight percent collagen. If one evaluates these amounts, it shows that in the case of microcrystalline collagen the binder content will vary from about 0.15 * to 2.5 *, where the impregnating flow: jv _e it from about 0.0055t to about 0.025 * micro-

contains crystalline collagen.

For surgical applications, e.g. for eye treatments, where a high rate of absorption is required, and at the same time high liquid absorption, is the preferred one Microcrystalline collagen content between about 0.4 * and about 1.25 * percent by weight. The specific binder content varies into a broader range, as set out above, independently of the particular film-forming polymer.

Example XIII

Example XII was repeated using gelatin

Solutions as impregnation solutions that are 0.5 *. 0.25 *. 0.05 * and oUi * contained gelatin. Pattern of sponges made with this if film-forming solution were prepared, were regarding iFibrillation. Rate of absorption for water and blood iCheck. The determined values of various sponge samples I can be found in Table 3 za.

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Table 3

. Impregnation
solution
% Gelatin Faservert Time bi
activity
water s Sat
in see.
blood Weight gain
in %
Water blood 2585 0.50; : o. < 1.5 3.9 2320 2602 V Ex.25 ^{: |} . \: 0.5 1.3 3.6 2583 2723 0.5 1 .1 1 .7 2692 2798 Pioi! ^{; i} ::: ¹ T O.ö 0.8 1.6 2510

Example XlV

Example XII was repeated, with solutions now available for the microcrystalline pollagen dispersion. Polyvinyl alcohol with a content of 0.1 fiew.- ?. and 0.01 wt% polyvinyl alcohol was used. Pattern before. Products made with these impregnation solutions were tested for fiber formation, absorption speed for water and blood and the weight gain in water and blood. These values are compiled in Table A.

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impregnation fiber value

solution % PVA '

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O-io * .:

0.5 0.5

^ eit to saturation in r; r. .
Water Ba-,

.6

Weight yield

in %

Water blood

327S 2668

3001 2962

whom

% It is of course obvious that others in the same way

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film-forming polymers as illustrated by the specific examples above are also useful. So is for example, in comparison to gelatine collagen, it can be hot-coagulated and dries faster to a not ^ Jclebrig tougher and less brittle coating skin than gelatin. While gelatine swells and softens on contact with water, troc *. en collage films to a skin that cannot be attacked by water. Acid Dispersions of collagen fibers, such as dispersions of acetic acid, citric acid, lactic acid, cianacetic acid and Malonic acids can be used instead of gelatin solutions and microcrystalline coating dispersions used to obtain products of the same; i properties see below. Procollagen and Collagenfibri Henkele

and dispersions are known and can, for example, hercj "? - i
! according to the information given in US Pat. No. 2,836,363 of ΐθ.6. * 9ί> ή

Sovie US Patent No. 2,920,000 by the '> .i.!? 60th

Similarly, 7.c \ lulosereaenerat au; Viscous and copper monoacellulose solutions confusing! *> t »/ ^ rrion for <J; e manufacture of products with only real properties. 5c for example when using. Viscose, these like * b: icr, for the production of Revon or cellulose senenerate films "with the usual way of 5% and c"% cellulose dissolved to the required cellulose content (0.005% to 0.250%). In this case, the washed sponge is impregnated with the diluted viscose gel and the excess liquid is removed, for example by squeezing it out. The viscose retained in the sponge is coagulated,

neutralizes the alkali and the cellulose by immersion des Schvaraaes regenerated in dilute sulfuric acid. If if desired, the regenerated cellulose can be desclmified and bleached and after removing an excess of liquid dr »r The sponge should be carefully washed in order to wash out liquid substances until the wash water is neutral. excess Water is removed, the sponge is dried and compressed to the desired bulk density, as described above. If so desired and especially if the Sharon intended is for industrial purposes, are used instead of viscose solutions Copper ammonia cellulose solutions are used.

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As is evident from the preceding description, one recognizes that particular, film-forming polymers and their amount are used depending on the purpose that the sponge is intended to fulfill, and that the degree of compression is also chosen depending on the purpose after using the sponge. For example, for sponges for eye and ear surgery, a smaller proportion of collagen-containing binding material is chosen with high compression, for general purposes or for tobacco smoke filters, less compression. In technical "contained use"; efnersystemen which, as • ♦ Freon containing ¹¹ and oil as a lubricant, is content to moisture harmful because it would freeze at the beginning of the expansion, and thus the system ineffective "eight or drove largely a refrigerant reduces the cooling effect

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Sy st (Mn of the sponge as a more or less permanent filter is used, and are present as drying agent through which the liquid passes. In such a use case, regenerated cellulose should be used and the amount thereof may be at the top of the ranking and the sponge is preferably in a highly compressed form For use as a wound care agent, microcrystalline collagen is preferred in view of its hemostatic properties and this can be used in higher amounts. It is of course clear that many other applications than filter media and drying agents are suitable for a person skilled in the art according to the above by itself

to offer.

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Claims (6)

Claims Pressed regenerated cellulose sponge, characterized in that that from 0.15 to 5 Gev.-Ji, preferably 0.4 to 1.25% by weight of a water-soluble one or dispersible, film-forming, hydrophilic polymer of high molecular weight and with a bulk density of at least 112 kg / m, preferably not more than 800 kg / m. 2. Sponge according to claim 1, characterized in that the polymer is microcrystalline collagen is. 3. Sponge according to claim 1, characterized that the polymer is gelatin. 4. Sponge according to claim 1, characterized in that the polymer is regenerated cellulose. 5. Sponge made of regenerated cellulose according to claims 1-4, characterized in that it has at least 25 times its absorption capacity compared to its own weight having. 6. A method for producing regenerated cellulose sponges according to claims i-5t thereby marked 409818/1088 : Yes ¹ i! Ch η e t. that the sponge is impregnated with a solution or dispersion of the polymer, each containing 0.005 to 0.25% by weight, preferably from 0.010 to 0.030% by weight of the polymer, and the impregnated swan is pressed, preferably up to a bulk density of 320 kg / m ³ to 800 kg / m ³ The method according to claim 6, characterized ge j _e i η. t. that the impregnated swarn is dried on a ax of volatile substances, which also include water, of not more than 0.5% by weight and the dried swarn on a moisture content of »» an- "est h Ge ..- *. preferably 7 -> 2 Gev .- * before its Kon, - is conditioned. 409318/1088