JPS62223213A - Moisture-curable urethane prepolymer - Google Patents

Abstract

PURPOSE:To obtain the titled prepolymer which is excellent in storage stability, has a controllable curing time in its use and is suitable for a paint, etc., by mixing a urethane prepolymer of a specified composition with a curing catalyst and a storage stabilizer at a specified weight ratio. CONSTITUTION:4,4'-Diphenylmethane diisocyanate is reacted with a polypropylene polyol of a number-average MW of 400-2,500 to produce a urethane prepolymer terminated with 4,4'-diphenylmethane diisocyanate and having a terminal NCO group content of 7-h15wt%. 100pts.wt. this urethane prepolymer is mixed with 0.1-2pts.wt. curing catalyst (e.g., triethylamine or N,N-dimethylaminoethanol) and 0.1-2pts.wt. storage stabilizer (e.g., isophthaloyl chloride or benzoyl chloride) to obtain the purpose moisture-curable urethane prepolymer.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a moisture-curing polyurethane prepolymer with excellent storage stability that can be used as a paint, adhesive, etc., or impregnated into an orthopedic cast bandage. Regarding.

(Conventional technology) Moisture-curing urethane prepolymer is a paint.

In addition to being used as an adhesive, in recent years, it has been increasingly used as an orthopedic cast bandage by impregnating glass cloth, polyester cloth, etc. Among these, the essential requirements for orthopedic cast bandages are: (1) It should harden in a short time after being set on the patient (21) The cast bandage should have appropriate strength after hardening (31) The product as a cast bandage should be used for a long period of time. For example, the product must not change or deteriorate even when stored and stocked.Among the above essential requirements (υ and (2)), the formulation was established early and the product is on the market, but it is not essential. Requirement (8)
It is extremely unlikely that a product that does not meet the above criteria will change its form during inventory and storage by medical supplies dealers, doctors, etc., and it is extremely common for the product to become unusable. This change in product form is caused by the solidification of urethane prepolymer impregnated with glass cloth, polyester cloth, etc., during inventory and storage. Although it may absorb moisture from the air and harden before being used as an orthopedic casting bandage, the curing catalyst increases in order to meet the essential requirements (11). During storage and storage, the rate of progress of the allocyanate reaction in the C-niurethane prepolymer increases, and there is a possibility that it will solidify due to self-polymerization.

(Objective of the Invention) The object of the present invention Q) is to meet the above-mentioned essential requirements for an orthopedic cast bandage + 11. The object of the present invention is to provide a moisture-curable urethane prepolymer that not only satisfies the requirements for fat of +21 but also satisfies the requirements for fat, which conventional products lack.

(Structure of the Invention) According to the present invention, this object is achieved by
．． Consisting of 4'-diphenylmethane diisocyanate and polypropylene polyol, the terminal is 4,4'-diphenylmethane diisocyanate, and the terminal -NC
The urethane prepolymer contains a curing catalyst and a storage stabilizer in an amount of 0.1 to 2.07 llj, respectively, to the urethane prepolymer.
This is achieved by adding 1 part.

Here, polypropylene polyol has two hydroxyl groups in one molecule and has a number average molecular weight of 400S2500, or has 3 g of hydroxyl groups in one molecule and has a number average molecular weight of 400 to 400. 2500, the average number of hydroxyl groups per molecule is 2 or more, 2.
It is formulated to have a value of 5 or less. Therefore, it has two hydroxyl groups in one molecule and has a number average molecular weight of 400 to
2500 range (: It is also possible to use some alone.

Here, if the average number of hydroxyl groups per molecule of polypropylene polyol is less than 2 (: means that the isoneate group is not necessarily present at the end of the urethane prepolymer, the elongation of the molecule due to reaction with water; Addition 1: As a result, the polymer cannot adopt a long-chain molecular structure.Thus, the polymer after curing by reaction with water has sufficient strength when applied as a paint, adhesive, or orthopedic casting bandage. Used without being able to express: Cannot be tolerated.

On the other hand, if the average number of hydroxyl groups per molecule of polypropylene polyol exceeds 2.0, the reaction between the urethane prepolymer and water (=therefore, parts forming a network structure occur, and as the network structure increases, the hardness gradually increases. In this way, when the average number of hydroxyl groups per molecule of polypropylene polyol exceeds 2.5, the network structure in the constituent molecules begins to occupy a considerable number. In addition, the length of the segment becomes too short, and as the hardness increases, brittleness becomes noticeable, making it unsuitable for use as paint, adhesive, orthopedic cast bandage, etc.

In the present invention, when the moisture-curable urethane prepolymer is used as a paint, an adhesive, or an orthopedic cast bandage, a polypropylene polyol is reacted with 4,41-diphenylmethane diisocyanate, and the terminal -NCO
It has been found that those containing 7 to 15% groups have appropriate strength and tenacity.

This ≦: On the other hand, -NCO group is 7 to 151 LIF, % range C: When synthesizing a certain urethane prepolymer, if a polypropylene polyol with a number average molecular distance of 400 or less is used, the viscosity of the urethane prepolymer will decrease. The problem is that the rise is too high, making it difficult to apply a thin coating.

Even if this product were temporarily coated, the cured product caused by the reaction with water is too hard and brittle, making it unsuitable for use as paints, adhesives, orthopedic cast bandages, etc.

Conversely, if the number average molecular weight of polypropylene polyol is 25
If a urethane prepolymer is used that has a -NCO group in the range of 7 to 15 by weight, the viscosity will be too low, and it will not be possible to secure a coating layer, and a sufficient binder effect cannot be expected. . Temporary Moon: Even when coated on glass fiber cloth as a bandage for orthopedic casts, liquid drips during storage after packaging, making it unusable.

Furthermore, the cured product resulting from reaction C with water is not sufficiently hard and cannot serve the role of fixing the affected area as a cast bandage.

The formulation effect of adjusting the number of hydroxyl groups in the present invention is that by adjusting the number of functional groups, even if prepolymers have the same -NCO group content (7 to 15% by weight in the present invention), (II) viscosity It becomes possible to adjust the hardness and strength of the cured coating film.

The tertiary amine that is the curing catalyst of the present invention is specifically triethylenediamine, N, N, N', N', N
〃-Pentamethyldipropylenetriamine, N, N,
N', Nl, N'-pentamethyldiethylenetriamine, N, N, N', N'-tetramethylhequinamethylenediamine, bis(dimethylaminoethyl) ether, 2-IN, N'-dimethylamino) 3-(N
, N-dimethylamino)propyl ether, N,N'-dimethylcyclohexylamine, N,N-dicyclohexylmethylamine, methylenebis(dimethylcyclohexyl)amine, triethylamine, N,N-dimethylcetylamine, N,N-dimethyldodecylamine, N,
N-dimethylhexadecylamine, N, N, N',
NI-tetramethyl-1,3-butanediamine, N,N
-dimethylbenzylamine, morpholine, N-methylmorpholine, N-ethelmorpholine, N-+2-dimethylaminoethyl)morpholine, 4,4'-oxydiethylenedimorpholine, N,Nl-diethylpiperazine, N,
N'-dimethylpiperazine, N-methyl + Nl-dimethylaminoetherpiperazine, 2I4.6-tri(dimethylaminomethyl)phenol, tetramethylguwanidine, 3-dimethylamino-N, N-dimethylpropionamide, N, N.

N1. Nl-tetra(3-dimethylaminopropyl)
Methanediamine, N,N-dimethylaminoethylur,
Etquinated hydroxylamine, N, N.

W, NI-tetramethyl-1,3-diamino-2-propanol, N,N,N'-trimethelaminoethylethanolamine, 1,4-bis(2-hydroxypropyl)2-methylpiperazine, 1-(2-hydroxypropyl)imidazole, 3,3-diamitu-N-methyldipropylamine, 1°8-diazobicyclo(5,4,0
)-undecene-7, N-methyl-NI-hydroxyethylpiperazine, etc., but preferably bis(dimethylaminoethyl)ether, 2-(N,N-dimethylamino)ethyl-3-(N,N- dimethylamino)propyl ether, triethylamine, N-(2-dimethylaminoethyl)morpholine, 3-dimethylamino-N,N
- Dimethylpropionamide, N, N-9 methylaminoethanol, or a combination of two or more thereof, and urethane prepolymer C: 0.1
Adding up to 2 parts by weight makes it worse.

The storage stability of the urethane prepolymer can be improved by adding an acid chloride compound as a storage stabilizer having two phases according to the present invention. As specific compounds of acid chloride, the following may be used. For example, isophthaloyl chloride, 2-ethylhextinoyl chloride, octanoyl chloride, chlorobenzoyl chloride, benzoyl chloride,
Salts (histearoyl, sebacoyl chloride, decanoyl chloride, dodecanoyl chloride, nonanoyl chloride, balmitoyl chloride, 3-phenylpropenoyl chloride, n-butameyl chloride, hexanoyl chloride, 2-methylpropanoyl chloride, 2,4-dichlorobenzoyl chloride) , 2,6-dichlorobenzoyl chloride, lauroyl chloride, methylbenzoyl chloride, etc. One or two of the above acid chlorides.
It is possible to use a combination of more than one species.

If the amount of acid chloride added is less than 0.1 part by weight of the urethane prepolymer r00, ζ2 will react with a small amount of moisture in the air during processes such as coating and packaging. , the storage stabilizing effect is not exhibited because the effect as a storage stabilizer is lost. In addition, the moisture in the air is sufficient (= no effect was observed even when treated with care).On the other hand, when the amount of acid chloride added is more than 2.0 parts by weight, the storage stability is excellent. However, the reaction rate with water during use is too slow, so ≦2,
Poor workability when used as paint, adhesive, or orthopedic cast bandage. In addition, a pungent odor peculiar to acid chloride is generated, and it also causes a negative effect on the product.

In addition, moisture-curing urethane prepolymers react with moisture and become polymerized, producing carbon dioxide gas. may foam, causing a decrease in strength or causing a blemish on the appearance. As a method of suppressing foaming due to the generation of carbon dioxide gas, a silicone-based antifoaming agent is added to a urethane prepolymer (0.01 to 1.
It is satisfied by adding 0iid parts. This silicone antifoaming agent is not meant to be used all the time, but it can be used depending on the situation.

Next, according to step C=, the moisture-curing urethane prepolymer containing a curing catalyst, storage stabilizer, antifoaming agent, etc. is to be used as an orthopedic cast bandage. It is impregnated with cloth, mesh, etc. made of fibers such as polyester, Kepler, polyaramid, ceramic, boron, stainless wool, etc., and packaged to be harvested from moisture in the air. To use, unwrap the packaging and soak the cloth or mesh impregnated with moisture-curing urethane prepolymer in water.
Immediately wrap it around the affected area and leave it standing until the urethane prepolymer hardens and develops strength (thus, the affected area is fixed.

Note that the impregnation of the urethane prepolymer into the base fabric is preferably in the range of 30 to 300% when the weight of the base fabric is 100%. When it is less than 30, the binder effect on the base fabric is insufficient and the necessary strength cannot be maintained. If it is more than 300, it may cause liquid dripping during impregnation, or a resin pool may form at the bottom C during storage after packaging, which is not suitable.In addition, when it is immersed in water, it is difficult for water to penetrate inside, so it hardens. This is undesirable because it takes a long time and makes the patient wait for a long time, and it also makes it difficult for the carbon dioxide gas generated during curing to escape, causing foaming.

(Example) The present invention will be described below with reference to Examples and Comparative Examples.

[Comparative example-1] 4.4 in a three-necked separable flask
775g of '-diphenylmethane diisocyanate was weighed out and heated to 50°C.Then, the average molecular weight was 11270.
0 polypropylene glycol was weighed and placed in a 27007 simple funnel, set in separable flask C, and the entire amount of polypropylene glycol was added dropwise over 1 hour while stirring the flask. At this time, the internal temperature of the flask was 50
The temperature was controlled to be in the range of -80°C. After dropping the entire amount of polypropylene glycol, the internal temperature of the flask was maintained at 75° C., and stirring was continued for 3 hours to synthesize a urethane prepolymer. The content of -NCO groups at the terminals of this product was measured by titration and found to be 50%.

Next is urethane prepolymer 100! Add 0.8 part of dimethylaminoethanol as a curing catalyst to the chain part, 0.5 part of lauroyl chloride as a bulk storage stabilizer to the chain part, and add O1'@ amount of silicone antifoaming agent. In addition,
Mix and stir thoroughly. This thing'ljf 5001&l
The mixture was divided into containers and sealed tightly, and the synthesis of the moisture-curing urethane preprimer was completed.

[Example-1] Using the same apparatus as Comparative Example-1, 4.
775 g of 4'-diphenylmethane diisocyanate,
Polypropylene glycol 170 with an average of 1700 per molecule
A urethane prepolymer was synthesized by weighing 0 g and performing the same operation as in Comparative Example-1.

The content image of the -NCO group at the end of this product is 7.111 (1
It was 1%. Next is urethane prepolymer 100! For the outer part, add 0.8 parts of dimethylaminoethanol, 0.5 parts of lauroyl chloride, and 0 parts of silicone antifoaming agent.
．． Add 1 part by weight, mix and stir 2 times for 500st
Container ≦: Collected and sealed tightly.

[Example-2] 4.4 using the same device as Comparative Example-1
1550 g of 1-diphenylmethane diisocyanate, polypropylene glycol 14GG with an average molecular weight of 1700
g was weighed out, and a urethane prepolymer was synthesized in the same manner as in Comparative Example-1. -NCO at the end of this thing
The group content image was lx, 911N1%. Next, 0.8 parts by weight of dimethylaminoethanol and 0.5 parts by weight of lauroyl chloride were added to 100 parts by weight of the urethane prepolymer.
0.11 [41 parts] of a silicone antifoaming agent was added to the image area, and after thorough mixing and stirring, the mixture was placed in a 500IIIt container and sealed tightly.

[Example-3] Using the same apparatus as Comparative Example-1, 4.
1550 g of 4'-diphenylmethane diisocyanate,
Polypropylene glycol 80 with an average molecular weight of 11,400
A urethane prepolymer was synthesized using the same procedure as in Comparative Example-1. -NC at the end of this thing
The content of O groups was 15.0t1%. Next, for 1 part of urethane prepolymer x00tt, 0.8 parts by weight of dimethylaminoethanol, 0 parts of lauroyl chloride,
After adding 1 part of 5lj and 0.1 part of a silicone antifoaming agent and stirring thoroughly, the mixture was placed in a 500st container and sealed.

[Comparative Example-2] Using the same apparatus as Comparative Example-1, 4.
1550 g of 4'-diphenylmethane diisocyanate,
Polypropylene glycol 600 with an average molecular weight of 1300
g was weighed out, and a urethane prepolymer was synthesized in the same manner as in Comparative Example-1. -NCO at the end of this thing
The content image of the group was 16.4 kenkichi. Next, to 1 part of the urethane prepolymer, 0.8 parts by weight of dimethylaminoethanol, 0.5 parts by weight of lauroyl chloride, and 90.1 parts by weight of a silicone antifoaming agent were added, and after thorough mixing and stirring, soomt. Aliquot it into a container and seal it tightly.

Examples 1, 2.3 and Comparative Example 1. The following operations were performed on each of the five samples of No. 2, and the evaluation was made as an orthopedic cast bandage.

[Evaluation method] E-Fabric correlation made of glass fiber Q, 0
35 Kuha impregnated a fabric tape with a mesh number of 90 numerical apertures/in'' and a fabric width of 7.5 cwa with a moisture-curable polyurethane prepolymer using a coater head of two rollers, and made an impregnated tape with a length of 4 seconds. The tape was wrapped in 5 layers around a plastic cylinder with a diameter of IQ cm, immersed in water for 130 seconds, and then left in air for 1 hour.
Immediately, the plastic cylinder was pulled out and a compression load was applied in the diametrical direction of the tape (5@) to measure its pressure resistance and breaking strain. 2 or more, rupture stain 20
% or more.

〔Measurement result〕

Here, pressure-resistant loading (K)) - Cylindrical diameter at the beginning of load when the yield point is indicated [Example-4] Using the same equipment as Comparative Example-1, 4.
885 g of 4'-diphenylmethane diisocyanate, 490 g of polypropylene glycol with an average molecular weight of 1700, and 30 g of polypropylene triol with an average molecular weight of 411,000.
A urethane prepolymer was synthesized from a mixture of 0 g and the same procedure as in Comparative Example-1. The content of the -NCO group at the terminal of this product was 11.9tt1%. 0.8 parts of dimethylaminoethanol, 0.5 parts of lauroyl chloride, and 0.1 parts of a silicone antifoaming agent were added to 100 parts of the following C nicretan prebolimer.
After thorough stirring and mixing, the mixture was fractionated into a 500-st container.

[Example-5] Using the same apparatus as Comparative Example-1, 4.
960 g of 4'-diphenylmethane diisocyanate, 350 g of polypropylene glycol with an average molecular weight of Too and 500 g of polypropylene triol with an average molecular weight of 1000
A urethane prepolymer was synthesized from the mixture of y in the same manner as in Comparative Example-1. The weight of the -NCO group at the end of this product was 11.9%. Next:
For 100 parts by weight of urethane brevolomer, 0.8 parts by weight of dimethylaminoethanol and 0 parts by weight of lauroyl chloride.
．． 5 parts by weight and 0.1 part by weight of a silicone antifoaming agent were added, thoroughly stirred and mixed, and then fractionated into a SOO Tsuru container.

[Comparative Example-3] Using the same apparatus as Comparative Example-1, 4.
4'-diphenylmethane diisocyanate 1030 g
Polypropylene glycol 21 with a C average molecular weight of 11,700
A urethane prepolymer was synthesized from a mixture of 0 g and 700 g of polypropylene triol having an average molecular weight of 111,000 in the same manner as in Comparative Example-1. The final content of --NCO groups in this product was 111% by weight.

Next C Nikretan prevolimer 100 parts! For two,
20.8 parts by weight of dimethylaminoethanol, 0.5 parts by weight of lauroyl chloride, and 0.1 parts by weight of silicone antifoaming agent were added, and the mixture was thoroughly stirred and mixed, and the mixture was collected at the mouth of a so-o-wag container. .

These Examples-4 and -5 and Comparative Example-3 were evaluated as orthopedic cast bandages according to the fFllli method described above, and the results are shown below. Note that the results of the previous Example-2 are also listed for reference.

Next, tertiary amine and acid chloride for the same prepolymer? I will explain the actual mi L<II by combining various A'lJ.

[Synthesis of prepolymer] Add 4,4'-diphenylmethane diisocyanate to a 3-unit separable flask.
00g was weighed out and the temperature was raised to 50°C. Then the average molecular weight is 7
00 polypropylene glycol (2800g) for dropping)! - It was weighed and set in a separable flask, and while stirring the flask, all of the propylene glycol was added dropwise over 1 hour. At this time, the temperature was controlled so that the internal temperature of the flask was within the range of 50 to 80°C. After dropping the entire polypropylene glycol dropwise, the internal temperature of the flask was maintained at 75°C, and stirring was continued for 3 hours to prepare the urethane resin. A polymer was synthesized.The terminal -NC of this polymer was synthesized.
The content of O groups was determined by titration to be 11.9%.

Add 0.1 parts by weight of a silicone antifoaming agent to the entire synthesized urethane prepolymer and stir for an additional 30 minutes.
The mixture was divided into 500% containers and sealed tightly.

This material is hereinafter referred to as a prepolymer.

A tertiary amine and an acid chloride were added to the prepolymer fractionated using the above method, and the pressure resistance and breaking strain were measured according to the evaluation method described above, and the curing time and storage stability were also determined. A sexual acceleration test was measured.

Here, the curing time is defined as a fabric tape made of E-glass fiber impregnated with a moisture-curable urethane prepolymer, immersed in water for 30 seconds, and then left in the air at room temperature.
It refers to the time it takes for the tack to disappear after touching the fabric surface with a finger, and is preferably 5 minutes or more and 20 minutes or less.

In addition, 42 accelerated storage stability tests were conducted as follows.

Weigh 509 of the moisture-curable urethane prepolymer into a polypropylene container with a capacity of 100@, and seal it tightly. This product is placed in an atmosphere of 130°C, and the fluidity of the prepolymer inside the container is observed every 100 minutes. Record the time. The longer the time to this end point, the better the storage stability (= better the prepolymer.

Margins below (Effects of the Invention) As described above, according to the present invention, a moisture-curing urethane prepolymer having excellent storage stability C and the ability to appropriately adjust the curing time during use can be obtained. It exhibits excellent performance in the fields of paints, adhesives, orthopedic casts, etc.

f'AlTl'D l:l'%1. =,...-1i.

Claims (1)

[Claims] 1) The urethane prepolymer is composed of 4,4'-diphenylmethane isocyanate and polypropylene polyol, and the terminal is 4,4'-diphenylmethane diisocyanate, and the -NCO group at the terminal is 7- The urethane prepolymer contains 0.1 to 2.0 parts by weight of a curing catalyst and 0.1 to 2.0 parts by weight of a storage stabilizer based on the urethane prepolymer.
．． A moisture-curable urethane prepolymer characterized in that 1 to 2.0 parts by weight of the prepolymer is added. 2) The polypropylene polyol has 2 or 3 hydroxyl groups in one molecule, and the average number of hydroxyl groups per molecule is 2 or more and 2.5 or less, and the number average molecular weight is in the range of 400 to 2,500. A moisture-curable urethane prepolymer according to claim 1. 3) The moisture-curable urethane prepolymer according to claim 1, wherein the curing catalyst is a tertiary amine and is composed of one or a combination of two or more tertiary amines. 4) The moisture-curable urethane prepolymer according to claim 1, wherein the storage stabilizer is an acid chloride, and comprises one or a combination of two or more acid chlorides.