JPH06209990A - Sealing material - Google Patents

Abstract

PURPOSE:To reduce the temperature dependency and improve the fitness with a living body by using the polyol which has the group represented by a special formula in the molecule, as polyol, as for a sealing material for an artificial organ consisting of polyisocyanate and polyol. CONSTITUTION:A sealing material for an artificial organ is constituted of (A) polyisocyanate and (B) polyol. In this case, as the (B) polyol, is used the polyol which has the group represented by the formula separately shown, in the molecule. Accordingly, the (B) polyol is obtained from the hydroxyl compounds and lactic acid, or if necessary, from the hydroxycarboxylic acids other than lactic acid. Accordingly, the sealing material which possesses excellent elasticity at ordinary temperature, excellent mechanical strength at a high temperature, excellent sealing performance, and excellent fitness with a living body, and is face, can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing material for artificial organs. More specifically, the present invention relates to a sealing material for artificial organs which is excellent in mechanical strength and temperature characteristics by using selected raw materials.

[0002]

2. Description of the Related Art Epoxy resins, polyurethane resins, etc. have been conventionally used as a sealing material for artificial organs. Examples of polyurethane resins include isocyanate as a main component, diisocyanate and castor oil and trimethylolpropane. An NCO group-terminated prepolymer in which castor oil or a mixture of castor oil and trimethylolpropane is used as a polyol as a curing agent (Japanese Patent Publication No.
8-26366) or an NCO group-terminated prepolymer composed of tolylene diisocyanate and a polyfunctional alcohol having a tertiary amino group in the molecule, polypropylene glycol, and castor oil (Japanese Patent Publication No. 53-29360). ) Etc. are known.

[0003]

However, conventional polyurethane resin encapsulants have drawbacks such as poor elasticity at room temperature and insufficient mechanical strength at high temperatures, and thus seals. There was a problem with sex. Therefore, it has been desired to introduce a polyurethane resin sealing material having a reduced temperature dependency.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above circumstances, and as a result, have found that the use of a specific polyol can be improved, and have reached the present invention. That is, the present invention relates to a polyurethane artificial organ sealant comprising (a) polyisocyanate and (ii) polyol in the molecule as (ii) polyol. It is a sealing material characterized by using a polyol having a group. In the molecule of (b) used in the present invention, The polyol having a group is obtained from a polyhydroxy compound and lactic acid, and optionally a hydroxycarboxylic acid other than lactic acid.

Examples of polyhydroxy compounds are ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexamethylenediol, Short chain glycols such as 3-methyl-1,5-pentanediol, 1,9-nonanediol, diethylene glycol and dipropylene glycol, polyethylene glycol having a molecular weight of 200 to 3000, polypropylene glycol, polyethylene adipate, polybutylene adipate, polycaprolactone Macroglycols such as diol and polycarbonate diol, or glycerin, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, sucrose, thoria Polyhydric alcohols such as Kanoruamin, alternatively, trivalent or more polyethers, polyesters and the like.

Examples of lactic acid include D-lactic acid and L-lactic acid.
Lactic acid, D, L-lactic acid, D-lactide, L-lactide,
Examples thereof include D, L-lactide and polylactic acid having a molecular weight of 162 to 10,000. Examples of hydroxycarboxylic acids other than lactic acid include glycolic acid, diglycolide, butyrolactone, valerolactone, caprolactone, lactic acid-glycolic acid copolymer, lactic acid-lactone copolymer and the like. As a method for obtaining a polyol from a polyhydroxy compound, lactic acid, etc., a known dehydration condensation method can be mentioned. That is, a predetermined amount of raw materials are charged into a reactor,
After reacting at ℃ ~ 180 ℃, further under reduced pressure 160
The reaction is completed at ℃ ~ 230 ℃. At this time, a catalyst, an antioxidant and the like may be used in combination, if necessary. In the present invention, other polyols may be used in combination with the above polyols, if necessary. Examples of other polyols include:
Examples thereof include polyether polyol, polyester polyol, polycarbonate polyol, polycaprolactone polyol, castor oil-based polyol and the like.

Examples of (a) polyisocyanate used in the present invention include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 2, 4'-diphenylmethane diisocyanate (2,4'-MDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI),
p-Phenylene diisocyanate, xylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, polymethylene polyphenylene polyisocyanate (p-MDI) Alternatively, trimers of these isocyanates, carbodiimide modified products, uretonimine modified products,
Examples of the polyisocyanate include buret modified products and the like, and these may be used alone or in any combination.
I, IPDI, etc.

The one-shot method and prepolymer are generally known as methods for producing polyurethane.
A particularly preferred method is the prepolymer method. The method for obtaining the prepolymer is 40 to 140 ° C., preferably 60.
At -120 ° C., the reaction may be carried out in a nitrogen atmosphere for 1 to 48 hours, preferably 3 to 12 hours. At this time, the NCO group / hydroxy group ratio of the isocyanate and the polyol is 1.1 to 15.0, and preferably 4.0.
It is in the range of 10.0 to 1.0, particularly preferably 5.0 to 9.0. When polyurethane is obtained from polyisocyanate and polyol, the NCO group / OH group ratio is 0.9 to 1.4,
It is preferably 0.95 to 1.2, more preferably 1.0 to 1.2.
It is 1.1.

The polyurethane sealing material according to the present invention is used as a sealing material when an embedding material such as a hollow fiber is embedded in an artificial organ such as an artificial kidney or an artificial lung. The embedding materials are generally nylon, cellulose, poval,
Acrylic and polysulfone type hollow fibers are used.
As a method for embedding these embedding materials, the centrifugal casting method described in West German Patent No. 1544107 is generally used.

[0010]

The polyurethane sealing material according to the present invention is
Compared with the conventional polyurethane encapsulant, it has a high elastic modulus over a wide temperature range. Moreover, since lactic acid-based polyol having high biocompatibility is used, the safety is high.

[0011]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. In addition, "part" in a sentence represents "part by weight" unless otherwise specified. In addition, each compound name is shown by an abbreviation,
The relationship between each compound and abbreviations is as follows. Diphenylmethane diisocyanate: MDI carbodiimide modified MDI (NCO content 29.0%): Modified MDI hexamethylene diisocyanate: HDI Isophorone diisocyanate: IPDI Polyethylene glycol having a molecular weight of 200: PEG2
00 polyethylene glycol having a molecular weight of 600: PEG6
00 ethylene glycol: EG diethylene glycol: DEG lactic acid-based polyol ^* : PLA * description of lactic acid-based polyol PLA-1: D, L-lactic acid / PEG600 / EG / DE
G copolymer, lactic acid content 55% by weight, molecular weight 1
Lactic acid-based polyol PLA-2: D, L-lactic acid / PEG200 / EG copolymer having a lactic acid content of 76% by weight and a molecular weight of 630 PLA-3: D, L-lactic acid / ε- Caprolactone / PE
G600 / EG copolymer, lactic acid-based polyol having a lactic acid content of 25% by weight and a molecular weight of 2000

[Preparation of Prepolymer] 4 equipped with a stirrer
Based on the composition shown in Table 1, an isocyanate and then a polyol were charged into a one-necked flask, and a prepolymerization reaction was carried out at 70 ° C. for 3 hours under a nitrogen stream. [Preparation of Polyol] Polyol A: a mixture of 825 parts of PLA-2 and 175 parts of tetrakishydroxypropylethylenediamine, having a hydroxy equivalent of 200. Polyol B: 820 parts of castor oil-based polyol (castor oil LAV manufactured by Ito Oil Co., Ltd.), tetrakis hydroxy. A polyol having a hydroxy equivalent weight of 209, which is a mixture of 180 parts of propylethylenediamine.

Examples 1 to 9 and Comparative Example 1 According to the combination of prepolymer and polyol shown in Table 2, a predetermined amount of prepolymer and polyol were weighed in a polypropylene cup, thoroughly stirred and mixed, and then defoamed. After the treatment, it was poured into a mold of 250 mm × 180 mm × 3 mm. This was heat-cured in an oven at 60 ° C. for 16 hours to obtain a sheet-shaped polyurethane. These polyurethanes were subjected to a tensile test according to JIS K6301. For the measurement of elastic modulus, Rheovibron DDV type manufactured by Orientec was used. The results are shown in Table 2.

[0014]

[Table 1]

[0015]

[Table 2]

Claims (1)

[Claims] 1. A sealing material for artificial organs of polyurethane comprising (a) polyisocyanate and (b) polyol, wherein (b) is a polyol in the molecule. An encapsulant characterized by using a polyol having a group.