KR19980031089A - Manufacturing method of yellowing resistant casting tape - Google Patents

Abstract

The present invention relates to a method for producing a yellowing resistant casting tape, and more particularly, in the presence of a bisphenol A morpholinoethyl ethoxylate catalyst represented by the following structural formula (I), an aliphatic and aromatic diisocyanate compound having a molecular weight of 200 to 5,000 A urethane prepolymer obtained by polymerizing a polyol compound is applied to a casting support such as glass fiber or synthetic fiber, thereby providing a casting tape having excellent yellowing resistance and breaking strength and capable of long-term storage.

Description

Manufacturing method of yellowing resistant casting tape

The present invention relates to a method for producing a yellowing resistant casting tape, and more particularly, in the presence of a bisphenol A morpholinoethyl ethoxylate catalyst represented by the following structural formula (I), an aliphatic and aromatic diisocyanate compound having a molecular weight of 200 to 5,000 A urethane prepolymer obtained by polymerizing a polyol compound is applied to a casting support such as glass fiber or synthetic fiber, thereby providing a casting tape having excellent yellowing resistance and breaking strength and capable of long-term storage.

Various casting methods have been developed and used, including plaster bandages (plaster of paris) to fix fractures in the body in surgery or orthopedic applications. The most widely used plaster of paris has a low strength-to-weight ratio, which requires a large amount of casting to maintain strength, which makes it bulky and heavy so that the patient can work. There was a lot of inconvenience. In addition, the gypsum bandage has a problem that it is difficult to determine the progress of the treatment because the poor breathability due to poor moisture evaporation from the wound, and poor x-ray (x-ray) permeability.

Many studies have been conducted to solve the disadvantages of the plaster bandages, and new synthetic casting tapes or other types of bandages have been developed to replace the plaster bandages (US Patent No. 3,241,501; US Patent No. 3,881,473; US Patent No. 3,932,526; U.S. Patent No. 4,131,114 and the like. In addition, in U.S. Patent Nos. 4,376,438, 4,427,001 and 4,411,261, the reaction between urethane prepolymer and water is carried out by casting a casting tape coated with a urethane prepolymer on a matrix such as glass fiber and immersing it in water like a gypsum bandage. A method of fixing a wound by cross-linking and hardening is disclosed. However, most of the prepolymers used in these methods are hard to be stored for a long time due to hardening in the packaging state, or have a problem of lowering the breaking strength value when hardened. In particular, the prepolymer becomes yellow over time after adaptation to the patient. There was a problem.

In the present invention, in order to supplement the problems of the conventional invention, a urethane prepolymer prepared by polymerizing an aliphatic and aromatic diisanate mixture and a polyol compound having a specific molecular weight range under the catalyst represented by the above formula (I) is applied to a casting support. The present invention has been completed by manufacturing a casting tape having better yellowing resistance and fracture strength than a conventional casting tape and which can be stored for a long time.

The present invention provides a method for producing a casting tape by applying a urethane prepolymer to a casting support, wherein the urethane prepolymer is used in combination with an aliphatic and aromatic diisocyanate compound in the presence of a bisphenol A morpholinoethyl ethoxylate catalyst represented by the following structural formula (I): The manufacturing method of the yellowing resistant casting tape using what superposed | polymerized the polyol compound of the molecular weight range 200-5,000 is characterized.

Referring to the present invention in more detail as follows.

The present invention is characterized by a method of producing a urethane prepolymer in a conventional casting tape manufacturing method of applying a urethane prepolymer to a casting support. In other words, in the present invention, by using an aromatic diisocyanate compound and an aliphatic diisocyanate compound as an isocyanate compound when preparing the urethane prepolymer, the handling and storage stability according to the use of the aromatic diisocyanate compound is improved, and the sulfur resistance according to the use of the aliphatic diisocyanate compound is used. Denaturation and light resistance were greatly improved. In the mixing ratio of the said diisocyanate compound, in order to achieve the objective of this invention, it is most preferable to mix and use an aliphatic diisocyanate compound 1: 3-1: 12 weight% with respect to an aromatic diisocyanate compound.

Specific examples of aromatic diisocyanate compounds that can be used in the present invention include 4,4'-methylene diphenyl diisocyanate (MDI; 4,4'-methylenediphenyl diisocyanate), toluene diisocyanate (TDI; toluene diisocyanate), naphthalene diisocyanate (NDI; naphthalene diisocyanate) and xylene diisocyanate (XDI; xylene diisocyanate) and the like, one or two or more selected from the use, in particular MDI is preferred for improving the handling and storage stability. In addition, specific examples of the aliphatic diisocyanate compounds that can be used in the present invention include hexamethylene diisocyanate (HDI; hexamethylene diisocyanate), isophoron diisocyanate (IPDI), and hydrogenated MDI (hydrogenated 4,4'-methylenediphenyl). One or two or more selected from diisocyanate) and hydrogenated xylene diisocyanate (XDI) are used. Particularly, using IPDI is preferable for improving yellowing resistance, light resistance and mechanical and thermal properties.

In addition, as the polyol compound, various types of polyester polyols or polyether polyols selected from polycaprolactone glycol, polyethylene glycol, polypropylene glycol, copolymers thereof, etc. having a molecular weight in the range of 500 to 2,000 may be used. Is a mixture of polypropylene glycol and poly (oxyethylene-oxypropylene) block copolymer having a molecular weight of 500 to 2,000 in a 5: 1 to 20: 1 molar ratio.

In the preparation of the urethane prepolymer according to the present invention, an excess of diisocyanate compound is used in comparison with the polyol compound. If the remaining isocyanate content (NCO%) in the prepolymer is too large, the initial set time is long and bubbles are formed during curing. There is a problem that occurs excessively, if the isocyanate content (NCO%) is too small, there is a problem that the adhesive strength at the time of curing is weakened, the strength of the casting tape is weakened after curing. Therefore, the isocyanate content (NCO%) dmf remaining in the prepolymer is preferably maintained in the range of 5 to 30% by weight. When this is converted into the input ratio of the diisocyanate compound and the polyol compound, it may vary depending on the type of the polyol compound to be used, but the diisocyanate compound is added in a 2 to 15 molar ratio to about 1 mole of the polyol compound.

In addition, the bisphenol A blanket represented by Structural Formula (I) in the present invention when preparing a urethane prepolymer to promote curing by reacting the diisocyanate compound with water when the casting tape is immersed in water and applied to the fracture site. Linoethyl ethoxylate; Amines such as triethanolamine, diethanolamine, tetramethyl-1,3-butanediamine, bis-2-dimethylaminoethyl ether and triethylenediamine; Morpholine compounds such as N-methyl morpholine, N-ethyl morpholine and dimorpholino diethyl ether; In addition, one or two or more selected from inorganic materials such as sodium bicarbonate, sodium carbonate, calcium carbonate, which are insoluble in the urethane prepolymer but insoluble in water are used as catalysts. This catalyst should be used to prevent hardening for at least two years in the packaging of the finished casting tape. Most preferably, the bisphenol A morpholinoethyl ethoxylate represented by Structural Formula (I) is used in the range of 0.1 to 5.0% by weight based on the total reactants.

In addition to the catalyst, one or two or more selected from benzoyl chloride, tosyl chloride, organic acid, organic acid anhydride, and the like are used as stabilizers in preparing the urethane prepolymer. When the excessive amount of stabilizer is added, there is a problem in that the initial set time is long.

In addition, when the casting tape is applied to the patient, foaming occurs during curing of the isocyanate and water, which lowers the strength of the cast and also reduces the number of air vents in the cast, thereby inhibiting the airflow. Occurrences should be minimized. As a method for this purpose, there is also a method of reducing the isocyanate content (NCO%) present in the prepolymer, but this is limited because it is accompanied by a decrease in reactivity, workability and viscosity. Therefore, in the present invention, a silicone compound having a viscosity ranging from 1,000 to 10,000 centipoise (cps) is added as a defoamer to prevent foaming upon curing with water, and most preferably, polysiloxane is used to prepare a urethane prepolymer. It is used in the range of 0.1 to 3.0% by weight based on the total reactants.

As described above, the urethane prepolymer prepared by the conventional polymerization method by adding isocyanate compound, polyol, compound, catalyst, stabilizer and antifoaming agent at a specific ratio maintains 5 to 30% of isocyanate content (NCO%). This is particularly advantageous in terms of strong adhesion and shortening of setting time.

The urethane prepolymer prepared by the above manufacturing process is applied to a casting support to produce a casting tape according to the present invention, wherein the prepolymer is 50 to 500 g, more preferably 100 to 300 g with respect to a matrix area of 1 m 2. Apply so that The casting support that can be used in the present invention is woven from fiberglass, polyester, acrylic, polyethylene, nylon and the like in the form of a woven or knitted fabric, which may be used.

In addition, considering the reactivity of the urethane prepolymer with moisture in the air, the product is packaged in a package where moisture in the air cannot pass immediately upon application. At this time, the used wrapping paper should be used so that moisture and water in the air cannot penetrate.

When using the casting tape packed, remove the wrapping paper, soak it in water for 10 ~ 30 seconds, take it out and wind it around wounds protected by cotton wool, and the fixing time of casting tape is at least 1 ~ 30 minutes, most preferably 3 ~ It should take about six minutes.

The yellowing resistant casting tape prepared by the manufacturing method of the present invention as described above has excellent fracture strength and yellowing resistance and long-term storage compared with the conventional casting tape.

Hereinafter, the present invention will be described in detail with reference to the following Examples, but the present invention is not limited thereto.

Examples 1-15 and Comparative Examples 1-2

Aromatic diisocyanate (manufactured by HD Polyurethanes Co., Isonate 143LK; 143 eq./g), isophorone isocyanate (IPDI) as aliphatic isocyanate in a well-dried glass reactor equipped with a stirrer, teflon stirring rod, thermometer and nitrogen line ; 111 eq./g), polysiloxane as a defoamer (Lucky-DC Silicone Co., Ltd .; DC ANTIFOAM 1400) and benzoyl chloride as a stabilizer were carefully added in the amounts shown in the following Table 1, followed by 20 minutes under nitrogen stream. Stirred. Polypropylene glycol (HD Polyurethane Co., Ltd., H-750D; 375eq./g) Poly (oxyethylene-oxypropylene) block copolymer (Korea Polyol Co., Ltd., KONION PE-61; 875 eq) / g) and bisphenol A morpholinoethyl ethoxylate were added as a catalyst, and then slowly increased so that the temperature and the stirring speed were 60 ° C and 200 rpm, respectively. After reacting at 60 ° C. for 2 hours, the mixture was cooled to room temperature under a nitrogen stream to obtain a urethane prepolymer. The prepared urethane prepolymer was applied to a glass fiber knitted fabric, and then wrapped with an aluminum wrapping paper to obtain a casting tape.

Table 1

Table 1 (continued)

(1) aromatic diisocyanate: HD Polyurethane Co., Ltd., Isonate 143LK; 143 eq./g).

(2) aliphatic diisocyanate: isophorone isocyanate (IPDI; 111 eq./g).

Hydrogenated MDI (from Aldrich; H ₁₂ MDI) in place of isophorone diisocyanate as aliphatic diisocyanate in Example 14

** Use of hexamethylene diisocyanate (Aldrich, HDI; 84 eq./g) instead of isophorone diisocyanate as aliphatic diisocyanate in Example 15

(3) Defoamer: Polysiloxane (Lucky-DC Silicone Co., Ltd .; DC ANTIFOAM 1400)

(4) Stabilizer: Benzoyl Chloride

(5) Polyol compound: Polypropylene glycol (HD Polyurethane Co., Ltd., H-750D; 375 eq. / G)

(6) Polyol compound: poly (oxyethylene-oxypropylene) block copolymer (Koriion Co., Ltd., KONION PE-61; 875 eq. / G)

(7) Catalyst: Bisphenol A morpholinoethyl ethoxylate

Comparative Example 3

A casting tape was prepared in the same manner as in Example 1, except that dimorpholinodiethyl ether (DMDEE) was used instead of basphenol A morpholinoethyl ethoxylate as a catalyst.

Example 16

A casting tape was prepared in the same manner as in Example 1, except that polyester fiber knitted fabric was used instead of glass fiber knitted fabric as a casting support.

Example 17

A casting tape was prepared in the same manner as in Example 1 except that an acrylic fiber knitted fabric was used instead of a glass fiber knitted fabric as a casting support.

Experimental Example 1

The urethane prepolymers prepared in Examples 1 to 17 and Comparative Examples 1 to 3 measured the isocyanate content (NCO%) and viscosity in the following manner, and the results are shown in Table 2 below.

Diisocyanate content (NCO%): The isocyanate content remaining in the prepolymer was measured by the Amine Equivalent Method presented in ASTM D2456.

Viscosity: The viscosity of the prepolymer was measured using a Brookfield Digital Viscometer (Model DV-II +) at 25 rpm with a rotational speed of 10 rpm.

[Table 2]

Table 2 (continued)

Experimental Example 2

Each of the casting tapes prepared in Examples 1 to 17 and Comparative Examples 1 to 3 measured physical properties by the following method, and the results are shown in Table 3 below.

Fracture strength: After 4 weeks of packaging, a 3-inch-wide casting tape was immersed in water for 30 seconds, then removed and pressed with both hands to squeeze out excess water and wound six times in a 5-cylinder aluminum cylinder surrounded by cotton bandages. After a certain period of time, the cured casting tape was removed from the cylinder, and placed between the holders of the instron (instron Model 4204) equipped with a holder designed and manufactured for the fracture strength measurement test of the present invention, and the crosshead was lowered and cast. The force required when the tape was pressed 1 cm was recorded. The descending speed of the crosshead was 2.8 mm / min.

Initial Set Time: The casting tape was wound around the cylinder in the same manner as the breaking strength measurement, and then, every 30 seconds, the index finger was pressed to record the time that the finger would not enter.

Shelf Life: The shelf life of the casting tape was measured by an accelerated test. The prepolymer was coated on a support, and the casting tape packed was stored in an oven maintained at 70 ° C., and after a predetermined time, it was taken out to check the degree of curing, and the time when the surface was cured was recorded. This time is called gel time. Generally, gel time is valid for 9 months at 23 ° C. if the gel time is 10 days at 70 ° C., and 2 years if the gel time is 30 days.

· Color value: After the casting tape is wound around the cylinder and cured in the same manner as the breaking strength measurement, and after a certain time, the L / a / b value measured by a color difference meter (Model SZ-∑90, Nippon Densyoku Kogyo) is measured. Recorded. L is a measure of brightness and has a value between 0 and 100. The larger the number, the brighter the color. a is a reddish color with a larger value in the positive direction, and a greenish color with a large value in the negative direction. b is a yellow-based color with a larger value in the positive (+) direction, and a blue-based color with a large value in the negative (-) direction.

Table 3

Table 3 (continued)

* Commercial product 1: 3M company, Scotch Cast ^TM plus

* Commercial product 2: Zimmer product, ZIM-FLX ^TM

According to the results of Tables 1 to 3, Examples 1 to 18 according to the present invention do not discolor for a long time, have excellent strength and can be stored for a long time, whereas Comparative Examples 1 to 2 and commercially available products are yellow when exposed to ultraviolet light for a long time. It has a low strength and short shelf life.

The yellowing resistant casting tape according to the present invention is particularly useful when used in surgical or orthopedic patients because of its excellent yellowing resistance and fracture strength and long-term storage properties.

Claims (8)

In the method for producing a casting tape by applying a urethane prepolymer to a casting support, the urethane prepolymer is an aliphatic and aromatic diisocyanate compound and a molecular weight of 200 ~ in the presence of a bisphenol A morpholinoethyl ethoxylate catalyst represented by the following structural formula (I): A process for producing a yellowing resistant casting tape, comprising using a polymer prepared by polymerizing a polyol compound in a range of 5,000. The method of claim 1, wherein the aromatic diisocyanate compound is used 3 to 12 times by weight based on the aliphatic diisocyanate compound. The method of claim 1, wherein the aliphatic diisocyanate compounds include hexamethylene diisocyanate (HDI), isophoron diisocyanate (IPDI), hydrogenated 4,4'-methylenediphenyl diisocyanate (MDI) and hydrogenation. Method for producing a yellowing-resistant casting tape, characterized in that used alone or in combination of two or more selected from hydrogenated xylene diisocyanate (XDI). The method of claim 1, wherein the aromatic diisocyanate compound is 4,4'-methylene diphenyl diisocyanate (MDI; 4,4'-methylenediphenyl diisocyanate), toluene diisocyanate (TDI; toluene diisocyanate), naphthalene diisocyanate (NDI A method for producing a yellowing resistant casting tape, characterized in that one or two or more selected from naphthalene diisocyanate) and xylene diisocyanate (XDI) are used. The method of claim 1, wherein the aliphatic and aromatic diisocyanate compounds are used in an amount of 2 to 10 moles per 1 mole of the polyol compound. The yellowing resistance according to claim 1 or 5, wherein the polyol compound is used alone or in combination of two or more selected from polycaprolactone glycol, polyethylene glycol, polypropylene glycol, copolymers thereof, and the like. Method of Making Casting Tapes. The method of claim 1, wherein the urethane prepolymer is prepared so that the isocyanate content is 5 to 30%. The method of claim 1, wherein the bisphenol A morpholinoethyl ethoxylate catalyst represented by Structural Formula (I) is used in an amount of 0.1 to 5% by weight based on the total reactants.