KR100448098B1 - Resin composition of polyurethane hardening by moisture and cast for orthopedic surgery prepared therefrom - Google Patents

Abstract

The present invention relates to a moisture-curable polyurethane resin composition, specifically from 50 to 70 based on a mixture of 32 to 42% by weight of a polyether polyol, the polyether polyol and an aromatic polyisocyanate based on the total composition. It is characterized by comprising 4.5 to 6.5 parts by weight of liquid paraffin and 5.0 to 8.0 parts by weight of hydrocarbon gel with respect to 100 parts by weight of the mixture consisting of weight% of aromatic polyisocyanate, the polyether polyol and aromatic polyisocyanate. The present invention also relates to an orthopedic cast prepared from the composition.

Description

RESIN COMPOSITION OF POLYURETHANE HARDENING BY MOISTURE AND CAST FOR ORTHOPEDIC SURGERY PREPARED THEREFROM}

The present invention relates to a moisture-curable polyurethane resin composition and an orthopedic cast produced by coating and molding the substrate on a substrate.

Conventionally, orthopedic casts used a gypsum bandage made of gypsum, but the weight was heavy, which not only burdened the patient but also caused the skin to bite as air did not penetrate. In addition, X-rays do not penetrate and have various problems. Recently, a moisture curable synthetic resin is used.

To date, cast compositions that can be used for surgery have been researched and developed, and such casts must meet the following conditions.

First, X-rays should not be disturbed by casts, secondly, it should be cured in a short time, and third, high heat generation during curing should not damage the skin. Fourth, air permeability is good. It should be easy to discharge sweat or foreign materials to prevent germs from propagating. Fifth, it should be light enough to facilitate the patient's activity but maintain sufficient strength. Sixth, it should have sufficient storage stability and finally harmless to human body.

Gypsum casts used up to now have a number of disadvantages such as high strength, heavy weight, poor air circulation, not only easy propagation of microorganisms, but also unsuitable for X-ray imaging.

In order to supplement the above problems of gypsum, a technique has been developed for hardening the polymer with moisture in a glass fiber impregnated with a polymer and using it in an orthopedic casting tape.

Polyurethane resins are used as the most representative polymers. Polyurethane resins are used in German Patent Publication Nos. 2,353,212, UK Patent No. 1,578,895, US Patent No. 4,376,438, and WO 81/00671. Is disclosed. In addition, US Pat. No. 4,433,680 discloses the use of dimorpholino diethyl ether as a catalyst to suppress side reactions while using polyurethane casts to have storage stability. Techniques for adding stabilizers are described in US Pat. Nos. 4,433,680 and 4,574,793. In US Pat. No. 4,667,661, polyethylene polyols, polysiloxanes or hydrophilic surfactants having a plurality of hydrophilic groups in a moisture curable resin have been used as a method for improving lubricity. U.S. Patent No. 4,397,146 introduces the use of lipophilic substances such as mineral oils as lubricants to improve lubricity. However, when such a lipophilic lubricant is used, when water is impregnated to harden the casting tape, condensation occurs on the surface of the casting tape due to the characteristics of the lipophilic lubricant. Therefore, not only the patient feels uncomfortable during the procedure, but also gives a good condition for the growth of microorganisms.

In order to solve the problems of the prior art as described above, the present invention improves lubricity by using a liquid paraffin to improve lubricity, and also by using a hydrogel type moisturizing substance in the polyurethane prepolymer, It is an object to provide a moisture curable polyurethane resin composition excellent in moisture retention properties.

It is also an object of the present invention to provide a surgical cast which can prevent the sedimentation of moisture by using the composition of the present invention in which a moisturizing agent is used.

The water-curable polyurethane resin composition of the present invention comprises 50-70% by weight of aromatic polyisocyanate based on a mixture of 32-42% by weight of polyether polyol, the polyether polyol and aromatic polyisocyanate based on the total composition. And 4.5 to 6.5 parts by weight of liquid paraffin and 5.0 to 8.0 parts by weight of hydrocarbon gel with respect to 100 parts by weight of the mixture consisting of the polyether polyol and the aromatic polyisocyanate.

The present invention also relates to an orthopedic cast, characterized in that it is produced by coating the above moisture-curable polyurethane resin composition on a substrate and molding.

Hereinafter, the present invention will be described in detail.

In the moisture-curable polyurethane resin composition of the present invention, the polyether polyol component is composed of a high molecular weight and a low molecular weight polyether polyol having a polyfunctional group, so that the flexibility and the crosslinkability can be maintained at a constant ratio to have appropriate physical properties. It is desirable to. At this time, it is preferable that the mixing ratio of high molecular weight and a low molecular weight polyether polyol is 50 to 65 weight% of high molecular weight polyether polyol among all the polyether polyol components, and 35 to 50 weight% of low molecular weight polyether polyol.

The content of the polyether polyol is preferably included 32 to 42% by weight based on the total composition. If the content is less than 32% by weight, the viscosity of the prepolymer is low, so that the resin flows during long-term storage of the cast, and the strength of the cast decreases. If the content is more than 42% by weight, the viscosity is high, and conversely, the looseness of the cast is problematic. And problems with storage stability.

In the moisture-curable polyurethane resin composition of the present invention, the aromatic polyisocyanate is, for example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate or a mixture of isomers thereof, and 4,4-diphenylmethane di Preference is given to diisocyanates such as isocyanates or mixtures thereof. In addition, general liquid-monomeric MDIs or pure monomeric MDIs as described in US Pat. No. 4,433,680 may be used. It is preferable that content of the said aromatic polyisocyanate component is contained in 50 to 70 weight% based on the mixture which consists of a polyether polyol and aromatic polyisocyanate. If the content is less than 50% by weight, there is a problem that the high viscosity is not easy to use, when it exceeds 70% by weight the viscosity is too low causing problems in the adhesiveness of the resin. In addition, there is a problem in safety due to excessive aromatic diisocyanate.

These polyether polyols and aromatic polyisocyanate components are polymerized to form prepolymers.

In addition, the composition of the present invention contains 4.5 to 6.5 parts by weight of lubricant based on 100 parts by weight of the mixture consisting of the polyether polyol and the aromatic polyisocyanate. The lubricant is preferably liquid paraffin. When the content of the lubricant is less than 4.5 parts by weight, it does not give sufficient lubricity and does not have the required workability. When the amount of the lubricant exceeds 6.5 parts by weight, the adhesiveness of the resin is significantly lowered and the viscosity is lowered, so that the resin flows during long-term storage.

Furthermore, the composition of this invention contains 5.0-8.0 weight part moisturizer with respect to 100 weight part of mixtures which consist of the said polyether polyol and aromatic polyisocyanate. The moisturizing agent is preferably a hydrocarbon gel. The lipophilic lubricant used in the present invention, when impregnated with water to cure the casting tape, causes condensation on the surface of the casting tape due to the properties of the lipophilic lubricant. Therefore, in addition to giving the patient an uncomfortable feeling at the time of treatment, the microorganisms give good conditions for propagation. The moisturizing agent, preferably the hydrocarbon gel, plays a role in preventing such condensation.

In addition to the components described above, various compositions commonly used in the polyurethane composition industry may be used in the composition of the present invention. For example, a small amount of a phosphoric acid compound generally used may be used as the storage stabilizer. In addition, antifoaming agents and UV stabilizers may be used.

In addition, various kinds of catalysts may be used in the composition of the present invention, including those already known for prepolymerization of the polyether polyol and aromatic polyisocyanate. Preferably, dimorpholinoethyl ether (DMDEE) is used. The content of the resin is preferably 1.0 to 1.9 parts by weight based on the total resin components. If the amount of the catalyst is less than 1.0 parts by weight, the curing time is too slow. If the content is more than 1.9 parts by weight, the curing time is too fast. Has a problem of low storage stability.

Orthopedic cast of the present invention is prepared by the following polymerization process. First, the components of the composition of the present invention are polymerized using a conventional polymerization method to synthesize a prepolymer. Synthesis procedure was carried out by inserting isocyanates such as diphenylmethane diisocyanate or toluene diisocyanate into a synthesis vessel equipped with a heater, a stirrer, and a dry air injector, and then raising the temperature to 55 to 60 ° C., followed by the aforementioned polyether polyol and antifoaming agent. The mixture of the UV stabilizer, the storage stabilizer, and the liquid paraffin is reacted while slowly injected into the reaction vessel with sufficient stirring. The reaction is exothermic and controlled so that the temperature does not exceed 90 ° C. The completion of the reaction is determined by examining the NCO% at its end, and the test uses the usual NCO% measurement. The end point ends when the NCO% reaches 12.5-14.5%.

Next, the necessary catalyst, humectant, and color paste are mixed and coated on the substrate, wherein the coating amount is 40 to 60% by weight based on the total amount of the substrate and the resin. The substrate used in the present invention may be any one made of a tape or nonwoven fabric woven from synthetic fibers, but in particular, the polyurethane resin composition of the present invention may have excellent properties using glass fibers and polyester-based synthetic fibers. do.

The orthopedic cast of the present invention is obtained in the form of a tape. At this time, the cast of the present invention is stored in an aluminum bag protected with air and moisture to maintain storage stability, taken out during use, soaked in water at room temperature for a while, wound around fractures and muscle injuries, and rubbed by hand to maintain an appropriate shape. It is used to make a shape similar to the body part.

Example

Hereinafter, the present invention will be described in detail through examples. However, these examples are only described for the purpose of illustrating the present invention by way of example, but the scope of the present invention is not limited to these examples.

The components used in this example are shown in Table 1, and the measurement results of the physical properties are shown in Table 2.

Examples 1-8: Polyurethane Resin Composition

While injecting nitrogen into the 1L reactor, the aromatic diisocyanate component shown in Table 1 was added and the reaction temperature was maintained at 55-60 ° C. Then, the polyether polyol component shown in Table 1 was slowly added, but the temperature did not exceed 90 ° C. It was.

All synthesis was carried out with a NCO% of 13.5%, and was measured after synthesis and completed when it came within ± 0.5% of the specified percentage range. After stirring, the reaction temperature was lowered to room temperature, a small amount of phosphoric acid was added at room temperature, and stirred for 30 minutes. Then, 1.67 parts by weight of dimorpholinoethyl ether (DMDEE) was added to the entire polyurethane resin as a catalyst, followed by stirring for 10 minutes. Thereafter, 5.5 parts by weight of KF-70 (Sujin Chemical Co., Ltd.), a liquid paraffin as a lubricant, was added to 100 parts by weight of the polyurethane resin. Subsequently, 6.2 parts by weight of a Versagel M-200 (manufactured by Penreco), a hydrocarbon gel, was added and stirred.

The prepared polyurethane resin composition was packaged with a 4 inch wide glass fiber as a substrate after 1 day of packaging, and the polyurethane resin composition prepared above was coated with a content of 45%, followed by an aluminum bag. Kept sealed.

Comparative Examples 1 to 3

While injecting nitrogen into the 1L reactor, the aromatic diisocyanate component shown in Table 1 was added and the reaction temperature was maintained at 55-60 ° C. Then, the polyether polyol component shown in Table 1 was slowly added but the temperature did not exceed 90 ° C. It was.

All synthesis was carried out with a NCO% of 13.5%, and was measured after synthesis and completed when it came within ± 0.5% of the specified percentage range. The reaction temperature was lowered to room temperature while stirring, a small amount of phosphoric acid was added at room temperature, and stirred for 30 minutes. Then, 1.67 parts by weight of dimorpholinoethyl ether (DMDEE) was added to the entire polyurethane resin as a catalyst, followed by stirring for 10 minutes. Thereafter, 5.5 parts by weight of liquid paraffin, KF-70 (Sujin Chemical), a lubricant, was optionally added to 100 parts by weight of polyurethane resin, as required in Comparative Example of Table 1. Next, Versagel M-200, a hydrocarbon gel, was added. 6.2 parts by weight of (manufactured by Penreco) was added and stirred.

The prepared polyurethane resin composition was packaged with a 4 inch wide glass fiber as a substrate after 1 day of packaging, and the polyurethane resin composition prepared above was coated with a content of 45%, followed by an aluminum bag. Kept sealed.

Measurement method used in this example

(1) measurement of compressive strength

Immediately after opening the cast sheet of the above example in a wrapping paper, it was taken out in water at 20 to 25 ° C, and then shaken hard to shake off moisture.

While spreading out the casting sheet, a 6-layer cylinder is wound with a constant force on a 5cm diameter cylinder. After 24 hours of storage in air, the compressive strength was tested in a tensile tester and the results are shown in Table 2 below. However, the speed of the tension gauge was 5 cm / min, and the load value received when 1 cm was reduced was calculated, and the unit was kg / cm three times, and the average was calculated. The results are shown in Table 2 below.

(2) lubricity test

As soon as the cast sheet of the above example was opened in a wrapping paper, a 200 g weight and a 2.5 cm diameter ball were placed on a ramp inclined at 10 degrees in a sealed box having a relative humidity of less than 1.0%, and then measured for a distance of sliding for 30 seconds. Shown in

(3) viscosity measurement

The resin prepared in this example was measured for viscosity using a Brookfield RVT viscometer with spindle # 4. Measurement temperature is 35 degreeC. The results are shown in Table 2.

(4) moisturizing experiment

After measuring the weight of the resin and the substrate except the cast sheet of the wrapping paper, the cast was put out in water of 20-25 ℃ for 10 seconds immediately after opening the cast in the wrapping paper and shaken hard to shake off moisture. Immediately weighing the amount of water contained, and measuring the amount of water falling by tilting the cast in the form of a cylinder for 5 minutes, the amount of water discharged is shown in Table 2 appropriately.

Table 1. Ingredients Used in Each Example

Example Ingredients and Usage (g) Isocyanate usage Polyether polyols usage slush usage Moisturizer usage catalyst usage One Isonate-143 LP 63.5 PP-2000GP-400 21.515.0 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 2 Isonate-143 LP 60.0 GP-3000PP-400 35.015.0 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 3 Isonate-143 LP 58.0 GP-4000PP-750 37.015.0 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 4 Isonate-143 LP 62.5 PP-3000GP-250 25.012.5 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 5 Isonate-143 LPIsonate-125 MK 33.530.0 PP-2000GP-400 21.515.0 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 6 Isonate-143 LPIsonate-125 MK 30.030.0 GP-3000PP-400 35.015.0 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 7 Isonate-143 LPIsonate-125 MK 30.028.0 GP-4000PP-750 37.015.0 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 8 Isonate-143 LPIsonate-125 MK 32.530.0 PP-3000GP-250 25.012.5 KF-70 5.5 Versagel M-200 6.2 DMDEE 1.67 Comparative Example 1 Isonate-143 LP 63.5 PP-2000GP-400 21.515.0 KF-70 0 Versagel M-200 0 DMDEE 1.67 Comparative Example 2 Isonate-143 LP 60.0 GP-3000PP-400 35.015.0 KF-70 0 Versagel M-200 6.2 DMDEE 1.67 Comparative Example 3 Isonate-143 LP 58.0 GP-4000PP-750 37.015.0 KF-70 5.5 Versagel M-200 0 DMDEE 1.67

In addition to the components shown in Table 1, in each of the examples, 0.1% of SAG-1000 (manufactured by Witco) as an antifoaming agent, 0.2% of ZICO A1 (manufactured by Zico Corporation) as a UV stabilizer, and 0.1% phosphoric acid as the stabilizer were added.

The properties of each component used in Table 1 are as follows.

Isonate-143 LP: Liquid Monomeric Products (Dow Chemical Products)

Isonate-125 MK: Monomeric MDI (Dow Chemical product)

PP-2000: Korean Polyol Products

GP-400: Korean Polyol Product

GP-3000: Korean Polyol Product

PP-400: Korean Polyol Products

GP-4000: Korean Polyol Product

PP-750: Korean Polyol Products

PP-3000: Korean Polyol Products

GP-250: Korean Polyol Product

KF-70: Seojin Chemicals

DMDEE: from Nitroil

Table 2. Physical property measurement result of the sheet for casting of each Example

Example Properties Compressive strength (kgf) Lubrication degree (℃ m) Viscosity (cps at 35 ℃) Moisturizing (%) One 89.6 156.0 38,000 0.9 2 88.2 168.0 32,000 0.6 3 85.2 148.0 31,000 0.7 4 93.0 168.0 28,000 0.8 5 87.2 175.0 36,000 0.9 6 85.4 189.0 42,000 1.1 7 82.2 155.0 43,000 0.9 8 89.6 172.0 39,000 0.2 Comparative Example 1 88.8 32.0 35,000 1.5 Comparative Example 2 90.2 24.0 32,000 0.2 Comparative Example 3 89.0 168.0 31,000 7.2

According to the composition of the present invention, by adding a polyether polyol to maintain a certain ratio of flexibility and crosslinking properties to have a proper physical properties, to complement the viscosity of the resin, to give excellent lubricity by using a hydrophobic liquid paraffin as a lubricant can do.

In addition, the surgical cast of the present invention can prevent the sedimentation of moisture by using the composition of the present invention in which a moisturizing agent is used.

Claims (4)

From 32 to 42% by weight of polyether polyols based on the total composition, from 50 to 70% by weight of aromatic polyisocyanates based on the mixture of said polyether polyols and aromatic polyisocyanates, said polyether polyols and aromatic polyisocyanates A water curable polyurethane resin composition comprising 4.5 to 6.5 parts by weight of liquid paraffin and 5.0 to 8.0 parts by weight of hydrocarbon gel with respect to 100 parts by weight of the mixture formed. The moisture-curable polyurethane resin composition according to claim 1, wherein the aromatic polyisocyanate is diisocyanate. An orthopedic cast prepared by coating the moisture-curable polyurethane resin composition of claim 1 with a substrate and molding. 4. The orthopedic cast of claim 3, wherein the substrate is glass fiber or polyester.