JPH04263865A - Hardener for hydraulic cast - Google Patents

Abstract

PURPOSE:To enhance the preservation stability of the hydraulic cast to be used by being fixed to the bone fracture, sprain and dearticulation parts which are orthopedic diseases or by being wound and attached to the prescribed part of a body for the protection, etc., of the body at the time of sporting and to relieve device conditions as well as to obtain adequate hardening time with the hardener for hardening the above-mentioned hydraulic cast. CONSTITUTION:A water-soluble polyamine is incorporated into the hardener for hardening the hydraulic cast formed by applying a hydraulic resin essentially consisting of an urethane polymer consisting of polyol and polyisocyanate on a fiber molding and sealing this molding into a moisture impermeable bag.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention can be used by wrapping or attaching to a predetermined part of the body to fix fractures, torsions, or dislocations in orthopedic diseases, or to protect the body during sports. This invention relates to a curing agent for curing hydraulic cast.

0002

[Prior Art] In order to fix, support and protect the site of orthopedic disease, a urethane prepolymer consisting of polyisocyanate and polyol is the main component, and a catalyst, stabilizer, antifoaming agent, coloring agent, etc. are mixed therein. A hydraulic cast made by impregnating and applying a hydraulic urethane resin composition to a relatively coarse knitted or woven base fabric made of fibers such as glass fibers, polyester fibers, aramid fibers, and wire fibers is enclosed in a moisture-impermeable bag. It is already known that the hydraulic cast is removed from the bag before use, soaked in water, and then wrapped or attached to the area of use to harden. This hydraulic cast is highly reactive with moisture and has problems in long-term storage. Various techniques have been proposed regarding manufacturing conditions, packaging materials, compounding aspects, etc., but none of them are satisfactory. For example, the manufacturing conditions include a technology in which the base material to be used is dried in advance to remove as much water as possible in the base material, and then applied in an atmosphere with a moisture content of 100 ppm or less; Technology that uses a moisture-impermeable material and encloses it in a bag after replacing it with nitrogen gas.In terms of compounding, the urethane prepolymer is separated from the catalyst and curing agent so that they come into contact with each other during use. Techniques for selecting types and combinations of the two have been proposed. However, the technology that attempts to respond to this from a manufacturing perspective has the problem of large equipment space, equipment costs, and environmental maintenance costs, and products in which the urethane prepolymer is separated from the catalyst and curing agent have good storage stability. During use, it is difficult to bring the urethane prepolymer into even contact with the catalyst, resulting in uneven curing. Furthermore, although the storage stability is considerably improved by the method of selecting catalysts and stabilizers, it is still not satisfactory. In other words, if you reduce the amount of catalyst or use a catalyst with slow catalytic action in an attempt to improve storage stability, or increase the amount of stabilizer blended, storage stability will improve, but the curing time during use will decrease. Conversely, the curing time becomes shorter, but the storage stability decreases, making it impossible to satisfy both storage stability and curing time.

0003

[Problems to be Solved by the Invention] The object of the present invention is to improve storage stability, to be able to manufacture the product using the same equipment and environmental conditions as ordinary hydraulic casting, and to cure within a sufficiently satisfactory time. An object of the present invention is to provide a curing agent for hydraulic casting that can be used for hydraulic casting.

0004

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a water-curable resin whose main component is a urethane prepolymer made of polyol and polyisocyanate is coated on a fiber formed product to prevent moisture. A curing agent for curing the hydraulic cast sealed in a permeable bag contains a water-soluble polyamine compound.

[0005] The water-soluble polyamine compound has a primary amino group,
It is preferable to have a secondary amino group or two or more of these in one molecule.

It is advantageous to form the curing agent as an aqueous solution containing more than 5% of the polyamine compound.

Methods for applying the curing agent according to the present invention to hydraulic casts include a method in which the hydraulic cast is directly immersed in an aqueous solution containing a polyamine compound to contact it, and a method in which the aqueous solution is sprayed or foamed to form a hydraulic cast. A method such as applying it on a cast can be used.

[0008]

[Operation] When the hydraulic casting curing agent of the present invention comes into contact with the cast polyurethane prepolymer, the amino groups of the polyamine compound and the isocyanate groups of the urethane prepolymer react to form urea bonds and grow into a polymer. The isocyanate groups of the urethane prepolymer react with water to create urethane bonds, producing carbamic acid, carbon dioxide, and an amine compound.Furthermore, this amine intermediate compound reacts with the isocyanate groups to form a polymer while creating urea bonds. A reaction occurs. The isocyanate of the urethane prepolymer has higher reactivity with the polyamine compound than with water, and selectively reacts with the polyamine compound to polymerize, that is, harden.
Curing time is shortened.

[0009]

[Example] Next, an example of the present invention will be described.

A1. A urethane prepolymer was synthesized by reacting the resin composition MDI with PPG having an average molecular weight of 850, and to this was added 15.8% of bisphenol A and 2.8% of TDMMEA [tri(2,6-dimethylmorpholinoethyl)amine]. %, 0.03% MSA (methane sulfonic acid) and 0.4% PEG (polyethylene glycol) were added to prepare a resin composition.

A2. A urethane prepolymer is synthesized by reacting the resin composition MDI with PPG having an average molecular weight of 700, and bis(N
, N-dimethylaminoethyl) ether (1.5%), benzoyl chloride (0.2%) as a stabilizer, and Irganox 1100 (trade name) as an antioxidant (0.2%).
A resin composition was prepared by mixing 0.1% of a silicone-based antifoaming agent. This resin composition has a smaller amount of catalyst than A1 and has a shelf life about 1.7 times longer.

B. Evaluation sample One of the above-mentioned resin compositions was applied at 230 g/m2 under low humidity conditions to a coarse base fabric with a basis weight of 340 g/m2 made of glass fibers made into a tape shape by Raschel knitting, and a 3 m
The sample was wound up into a roll, replaced with nitrogen, inserted into a highly waterproof bag made of a laminate of aluminum film, nylon, and polypropylene, and sealed with a heat seal to serve as an evaluation sample.

C1. Hardening agents A hardening agent was prepared by dissolving guanidine carbonate as a primary amine, piperazine as a secondary amine, and 3-amino-1,2,4-triazole as a material containing primary and secondary amines in water.

C2. hardening agent For comparison, water, which is conventionally used, was used as a curing agent.

[0015] The following table shows the evaluation of tack disappearance time and curing time for Examples and Comparative Examples of the present invention. In Examples 1 to 9, the evaluation specimen shown in B was prepared using the resin composition shown in A1. Comparative Example 1 is an example in which C2 water is used as a curing agent for the same evaluation sample, and Example 10 is an example in which the resin composition shown in A2 is used. Prepare the evaluation sample shown in B, and
Comparative Example 2 is an example in which the curing agent was evaluated using C2 water as the curing agent for the same evaluation specimen.

[0016] The test method was to take a sample out of the bag, stack it on release paper in three layers, apply a hardening agent solution, and measure the time until the stickiness on the surface disappeared when touched with a finger, which was determined as the tack disappearance time. In addition, the specimen was folded in 4 layers to a size of 10 cm x 15 cm.
The curing time was determined by measuring the time it took for the piece to be cut and coated with a hardening agent to harden and retain its shape.

According to the test results, the curing agent according to the present invention has extremely good tack disappearance time and curing time, and the curing agent concentration is preferably 20 to 30%, and even if the concentration is higher than that, the effect increases significantly. On the other hand, the coloring property increases and there are some problems with solubility.

[0018]

[Table 1]

[0019]

[Effects of the Invention] According to the present invention, since the curing time of hydraulic cast can be shortened, the conventional techniques of blending highly active catalysts or increasing the amount of catalyst blended are no longer necessary. It is possible to use a catalyst with low activity or to reduce the amount of catalyst blended, and the storage stability of the hydraulic cast is increased. Furthermore, the fact that this low-activity catalyst can be used and the amount of catalyst blended can be reduced leads to relaxation of the manufacturing conditions for hydraulic casting.

Furthermore, when the curing agent of the present invention is used in conventional hydraulic casts, the curing time is shorter than that of conventional castings, so it is particularly advantageous for pediatric patients who wish to shorten the curing time or for use in orthodontic purposes. Furthermore, after applying the cast to the affected area, it is possible to advantageously apply a hardening agent in the form of a spray or foam to partially harden the cast.

Claims (4)

[Claims] Claim 1: A curing agent for curing a hydraulic cast in which a hydraulic resin mainly composed of a urethane prepolymer consisting of polyol and polyisocyanate is applied to a fiber formed product and sealed in a moisture-impermeable bag. A curing agent for hydraulic casting, characterized by containing a water-soluble polyamine compound. 2. The curing agent for hydraulic casting according to claim 1, wherein the water-soluble polyamine compound has two or more primary amino groups in one molecule. 3. The curing agent for hydraulic casting according to claim 1, wherein the water-soluble polyamine compound has two or more secondary amino groups in one molecule. 4. The curing agent for hydraulic casting according to claim 1, wherein the water-soluble polyamine compound has two or more primary amino groups and two or more secondary amino groups in one molecule.