DE2919354A1 - Orthopedic bandage with improved stickiness and workability - Google Patents

Description

DIPL.-ING. HANS W. GROENING

PATENT ADVOCATE

- · J -

J / J 10-171

The invention relates to 'an orthopedic bandage due to a polymerization reaction catalyzed by free Kadikaie cures and which contains a Polyväfhylenoxidharz to the Initial tack and initial processability within one improve the wide temperature range of the water used for dipping the sanitary napkin. The bandage contains a flexible one Carrier with a casting compound applied to it, which is polymerizable by means of a Redpx catalyst system monomeric compound contains »In the case of the monomeric compound, can it is a solid, water-soluble vinyl monomer, such as Diacetone acrylamide (DAA), N-isopropyl acrylamide (N-IPA) or Mixtures thereof, act = The polymerization of the monomeric compound is initiated by placing the casting compound in the presence a redox catalyst system in connection with water brings, for example, by dipping the bandage to which the redox catalyst system is applied in tap water.

Plaster of paris applied to tissue or gauze has so far been used almost exclusively used to make surgical dressings that are used to dress parts of the body, such as legs, arms, wrists, Neck and the like, immobilize and support.

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Plaster of paris is a cheaper, more practical material that can be used easily by simply immersing it in water. Come in addition, that practically all doctors, especially orthopedic specialists, have been working with plaster of paris for a long time are familiar with the application. Because of this, they are reluctant to do so - willing to try other techniques for the creation of associations that work with other media.

The use of plaster of paris for such purposes has certain advantages Disadvantages with itself. Plaster of paris is relatively heavy and can be damaged by the action of water. Fernsr is across from plaster of paris X-rays essentially opaque so that it is occasionally necessary to remove a bandage for example, to determine whether a fracture has healed satisfactorily.

The foregoing difficulties in using plaster of paris-based orthopedic bandages have led to the development of other orthopedic bandages, such as those described in U.S. Patent 3,630,194. The bandage according to this publication uses a mixture of a water-soluble monomeric compound from the DAA ₁ W-IPA group and mixtures thereof as the casting compound, it being possible for these monomeric compounds to be polymerized in the presence of water by means of a redox catalyst system that contains an oxidation component and a reduction component . This bandage hardens in a similar way to conventional plaster of paris bandages by immersion in tap water. The advantage of this method, in contrast to the use of other sanitary napkins that use thermoplastic films or apply curable resins in the form of a slurry, is that personnel working with this sanitary napkin do not have to learn new techniques for making a bandage. The sanitary napkins of U.S. Patent 3,630,194 are

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while satisfactory in several respects, it still suffers from certain disadvantages. For example show such a tie after immersion in water to initiate the curing process within the first 50 seconds low stickiness. It is possible to achieve satisfactory tack by adding additional catalyst to accelerate the polymerization reaction at an earlier point in time, however, this leads to the Processing time, which is available to the doctor applying the bandage, is significantly reduced.

The object of the invention is as an additive for casting compounds of orthopedic bandages that increase tack in the initial stage without participating in the polymerization reaction take part, and thus gives the treating physician sufficient processing time.

The aforementioned object is achieved according to the invention by adding a polyethylene oxide resin with a special molecular weight range dissolved on the surface of the bandage.

US Pat. No. 3,746,680 describes gypsum masses, the polyethylene oxide resins with molecular weights ranging from 100 to 4,000,000. These masses show a high "Green strength". (Which within a short time, for example xireise strength of the plaster cast reached within 1 hour.

The inventive use of polyethylene oxide resins with different molecular weights compared to the prior art serves a completely different and unobvious purpose (with a molecular weight different from the prior art) is used for this purpose. Stickiness in the initial stage su cause ,, that 'means. "." ""' * '-

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the ability of a material / due to its adhesive properties to remain at the place of application. Such a difficulty arises with systems based on gypsum due to the lack of elasticity of the gauze used and the heavy weight of the gypsum paste. On the other hand such Difficulties with the system according to the invention very much on, which is due to the high elasticity of the substrate and the general lack of adhesiveness in the early stages of the polymerization reaction is due.

Thus, according to the invention, orthopedic bandages are available provided, which contain a casting compound applied to a flexible carrier. This casting compound contains a Redox catalyst system, one by this redox catalyst system polymerizable monomeric compound and a polyethylene oxide resin. . Water-soluble, solid vinyl monomers and in particular DAA, N-IPA or mixtures thereof are preferred used. The orthopedic bandages of the invention are prepared for use by leaving them in the presence a catalytic amount of a redox catalyst, for example a copper salt, with an aqueous medium, preferably tap water, brought into contact. It will the vinyl monomer polymerizes. The polymerization catalyst can be added to the aqueous medium itself. One Another possibility is that the catalyst is incorporated into the casting compound. In the latter case, there is one dry storage required and contact with humid air to be avoided. Both the copper salt and the reducing agent are used to initiate the polymerization reaction are required, it is possible to add a catalyst component not to the casting compound, but rather at the time of use add to the water in which the bandage is immersed. This increases the sensitivity of the bandage to Reduced water and humid air.

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But there is also the possibility of using both catalyst components to incorporate the casting compound so that the "orthopedic surgeon only has to immerse the bandage in water in order to." initiate polymerization and make the sanitary napkin ready for use. This simple procedure thus works essentially identical to conventional methods of making plaster casts. Will not be the entire catalyst incorporated into the casting compound, the orthopedic surgeon only needs the catalyst component or components that are missing Add water in which the pad is dipped.

As already mentioned, such sanitary napkins based on vinyl polymers exhibit a breakdown within the first 50 seconds low stickiness, which makes it difficult to use by the orthopedic surgeon. This · serious difficulty leaves overcome according to the invention by placing a polyethylene oxide resin with a molecular weight on the surface of the bandage from about 4,000,000 to about 5,000,000 in a concentration of about 0.15 to 0.35 percent and preferably from about 0.20 to 0.25 percent, based on the total weight of the coated bandage, "

The resin used in the present invention has an average Molecular weight (hereinafter referred to as molecular weight for short) of about 4,000,000 to 5,000,000. Preferably acts it is one of the blends of polyethylene oxide resins available from Union Carbide Corporation under the trade name "Polyox". Polyethylene oxide resins with molecular weights below the specified limits, which are also sold under the trade name "Polyox" or sold under other trade names are not suitable for the production of the products according to the invention Bind, as they tend to go into solution and do not produce the desired tackiness. In the manufacture of the bindings according to the invention suitable polyethylene oxide

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resins are thermoplastic, water-soluble and highly crystalline products. Polyethylene oxide is particularly preferred with the highest possible percentage of crystallinity.

In Table I are the typical properties of crystalline Polyethylene oxide resins used in the invention can be put together.

Table I.

Average

Molecular weight '4 °°° ^oo ° to ^5,000 ° °°°

Melting point 62 to 65 ° C

specific gravity 1.15 to 1.26 g / cm

Bulk Density '' 0.384 g / cm (24 lb / ft ³ )

Particle size 98 percent pass in

Sieve of the clear mesh size ö, 841 imi (20 mesh)

Percent crystalline content about 95 percent

As discussed above, the polyethylene oxide resins are based on a concentration of about 0.15 to 0.35 percent used based on the total weight of the coated napkin. If less than about 0.15 percent is used, the required Stickiness not reached. If the proportion is greater than about 0.35 percent, there is a considerable reduction the desired water resistance of the finished dressing.

The reducing agents suitable for producing the redox catalyst system are known per se. Examples are Iron (II) sulfate, sodium sulfite, sodium dithionite, iron (II) chloride, Sodium formaldehyde sulfoxylate, oxalic acid, cobalt (II) chloride and hydrazine. The reducing agents mentioned are known and are suitable components for redox catalyst systems

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can be used to produce the bandages according to the invention will.

As an oxidizing agent of the redox catalyst system, a Serving copper salt. The copper salt is generally characterized by this characterizes that it is partially soluble in water at room temperature. Very soluble copper salts, such as sulphates and chlorides, put copper ions in such massive concentrations free that the polymerization of the monomeric compound proceeds very quickly and the curing time of the bandage only difficult to control. Partially soluble copper compounds, such as acetylacetonate, set just enough lots of copper ions free that a bandage with one for that Practically acceptable processing time (6O to 7O seconds) arises. Largely insoluble copper compounds, such as phosphate, do not release a sufficient number of copper ions to initiate the polymerization.

The oxidizing agent, for example a copper salt, can be used in an amount of from OooS 'to 5 percent and preferably from 0.01 to 0.15 percent, based on the weight of the napkin, (either incorporated into the bandage or added to the immersion water). The molar ratio of reducing agent to copper salt can vary from 100: 1 to 5: 1. It is preferably 50: 1.

Glass fibers are used to produce the bandages according to the invention preferred as a flexible support. The reason for preferring such fabrics is that they are used for strength of the association during which the activation

send earlier stages contribute. Thus, glass fibers contribute to the "green strength" of sanitary napkins made from such napkins Associations at «. Glass fiber fabrics, which are made from a very brittle fiber, have a particularly remarkable

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appreciate lack of deformability. The addition of a 1,2-di-tert-glycol, like pinacol, to sanitary napkins containing fiberglass fabric makes the sanitary napkins malleable and lighter their winding without adversely affecting the desired strength properties of these bandages based on glass fibers.

The amount of molding compound can be 50 to 100 percent and preferably 65 to 75 percent based on the weight of the flexible carrier. Based on the total amount of solids in the casting compound, the proportion of the monomeric compound can be about 75 to 100 percent and preferably 85 to 95 percent, based on the weight of the total mass. The rest consists of binders, fillers, comonomers (different from distinguishing the water-soluble, solid vinyl monomers monomeric compounds), redox catalyst components (if they are incorporated into the casting compound) and the like.

The bandages according to the invention can be similar to the Manufacture, package, and use bindings of U.S. Patent 3,630,194. In the document mentioned are materials that are used to Production of the binders according to the invention are suitable, such as redox catalysts, flexible carriers, monomers, comonomers, binders, fillers, controlling the rate of polymerization Compounds and the like. In this regard, reference is made to the content of this document. This also applies to the manufacture, packaging and use of the sanitary napkins according to the invention. Is in the inventive Orthopedic bandages use a copper salt so no buffers are required. When using per-sulfates as initiators Large quantities are required, which are damaging to the skin due to the acidic decomposition products of the persulfates. In this case the addition of a buffer is necessary. When using copper salts as oxidizing agents are so small amounts required that the pH of the moist

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Tie does not change. Sodium sulfite is used as a coreagent too Copper (II) acetylacetonate preferred, ■ since it is also used as Buffer works.

The examples illustrate the invention.

example 1

By a melt, the 975 parts of diacetone acrylamide, 20 parts Polyethylene glycol (molecular weight 4000, for example Carbowax 4000 from Union Carbide Corporation, New York), 43 Parts of pinacol and 10 parts of a molecular sieve such as the molecular sieve 3A from Union Carbide Corporation, Linde Division, New York, is a fiberglass fabric with a Moves at a speed of 2.4 meters / min (8 ft / min). Before the When the melt solidifies, a catalyst mixture is sprayed on in an amount of 6 g / min. This catalyst mixture contains 136 parts of a premix (containing 960 parts of sodium sulfite and 40 parts of copper (II) acetylacetonate), 644 parts of sodium sulfite and 17 parts of a polyethylene oxide high molecular weight (about 5,000 oco-) such as Polyox Coagulant Grade from Union Carbide Corporation, Chemicals and Plastics Division, New York. The impregnated fabric is then cut into napkins about 2.70 meters (3 yards) long. The bandages obtained show when used for Manufacture of dressings have excellent initial tack and do not show any negative properties.

Example 2

A fiberglass fabric is moved at a speed of 9 meters / min (30 ft / min) through a melt consisting of 1950 g of diacetone acrylamide, 40 g of polyethylene glycol with a molecular weight of 4000 (Carbowax 4000), 60 g of amorphous silicon dioxide (Aerosil R-972), 20 g molecular sieve (type 3A) and 86 g pinacol.

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By mixing 30 minutes of 305 grams of sodium sulfite, 17 grams Copper (II) acetylacetonate and 1O2 g of anhydrous calcium sulphate a premix is made. This premix is made with 88 g of polyethylene oxide resin having an average molecular weight of 5 Όσο ooo ■ and mixed with 2776 g of sodium sulfite. Mix for 15 minutes. The mixture obtained is applied in an amount of 11 g / min to that coming from the melt Fabric sprayed. The fabric is ready for use after the melt has completely solidified.

Example 3

A new bandage is made as in Example 2, with the modification that 88 g of polyethylene oxide resin with an average molecular weight of 100,000 instead of 88 g of polyethylene oxide resin having an average molecular weight of 5,000,000 can be used.

Example 4

A napkin according to Example 2, except that 88 g Polyäthylenoxidharz having an average molecular weight of 300 OOO in place of 88 g Polyäthylenoxidharz having an average molecular weight of 5 ooo ooo <■ be used.

Example 5

A bandage is made according to Example 2, with the modification that 88 g of polyethylene oxide resin with an average molecular weight of 600,000 instead of 88 g of polyethylene oxide resin having an average molecular weight of 5,000,000 can be used.

Example 6

The bindings of Examples 2 to 4 are examined according to the following procedure. Bandages each 1.20 meters (4 yards) long are immersed in tap water at 24 C (75 ° F) and then wrapped on a piece of wood shaped like a forearm. The occurrence of stickiness is assessed by the person skilled in the art of winding the bandage as the state in which, when the bandage is unwound, the formation of polymer threads becomes visible and an adhesive bond between the layers of the bandage can be felt. “% Addition” is to be understood as 100 times the quotient of the potting compound and the sum of the potting compound and the substrate. "Kat / DAA" means the weight ratio of catalyst mixture to potting compound. "Beginning of the creamy state" means the state in which the sanitary napkin is easy to work with and has a good consistency.

The results are shown in Table II.

Table II

example Example 2 Example 3 Example 4 Example 5 % Addition 39.2 39.0 39.5 39.9 Cat / DAA. 0.091 0.093 0.093 0.085 Beginning of the adhesive
rigkeit, see. 15th 75 58 .67 Beginning of the creamy
State, see. 18th 50 68 35

From the above results, it can be seen that only the napkin of Example 2 containing a polyethylene oxide resin has its molecular weight lies within the scope essential to the invention,

the desired properties for a quick start the stickiness and the creamy state.

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Claims (6)

IiIP] L. “ING. HANS W. GROENING 29 19 35 A FATE NTAKWALT Johnson & Johnson 5o1 George Street New Brunswick, New Jersey USA J / J 10-171 Orthopedic bandage with improved tack and workability Claims 1. Orthopedic bandage with improved tack and workability in the initial stage, characterized by a content of one applied to a flexible carrier Casting compound, which is a water-soluble, solid vinyl monomer, a catalyst which catalyzes the polymerization of the monomer in the presence of water and a polyethylene oxide resin with an average molecular weight of 4,000,000 to 5,000,000. 2. Orthopedic bandage according to claim 1, characterized in that the monomer from the group diacetone acrylamide, N-isopropyl acrylamide or mixtures thereof. 3 = orthopedic bandage according to claim 1, characterized in that that it contains a redox catalyst system as a catalyst. 909847/0704 YOU BERTSTH. 4 8000 KUKOHEN 88 - POB 860340 CABLE: RHEINPATEIiT TEL. (089) 471079 TELEX 5-82859 4. Orthopedic bandage according to claim 1, characterized in that the redox catalyst is a copper salt as the oxidizing agent contains. 5. Orthopedic bandage according to claim 1, characterized in that the Polyäthylenoxxdharz about 0.15 to 0.35 percent the casting compound. 6. Orthopedic bandage according to claim 1, characterized in that it is a fiberglass fabric as a flexible carrier contains. 909847 / O7Ö4