JPH06192375A - Crosslinked material of polymer composition and its production - Google Patents

Abstract

PURPOSE:To obtain the subject crosslinked material easily producible, excellent in heat resistance and biodegradability and useful in the field of medical care, agriculture, fishery, etc., by crosslinking a polycaprolactone having high mol.wt. with a polyurethane elastomer. CONSTITUTION:This crosslinked material is obtained by continuously feeding (A) a polycaprolact one having high mol.wt., (B) a polyurethane and (C) an isocyanate catalyst such as xylene diisocyanate into an extruder at a ratio (component A/B) of 95/5 to 30/70 preferably at a resin temp. of 130-300 deg.C to lead to kneading-crosslinking of the mixture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer obtained by cross-linking a high molecular weight polycaprolactone and a polyurethane elastomer having excellent heat resistance and biodegradability, and a method for producing the same.

[0002]

2. Description of the Related Art Recently, aliphatic polyesters such as polycaprolactone as biodegradable synthetic polymer compounds have been aimed at application to the fields of medicine, agriculture, forestry and fisheries and industrial materials, and in connection with waste treatment problems. Development research is being conducted. However, although the aliphatic polyester exhibits biodegradability, it has a low melting point and poor heat resistance, and is practically used for containers and
It could not be used for a wide range of purposes such as films and fibers. Therefore, aliphatic polyester and other thermoplastics such as polyethylene, polypropylene, polystyrene,
A composition in which heat resistance and the like were imparted by blending with a resin such as polyethylene terephthalate or polyamide was investigated, but biodegradability was not always satisfactory.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is a synthesis which is excellent in heat resistance, can be easily produced in a short time, and is excellent in biodegradability. It is intended to provide a polymer compound.

[0004]

Means for Solving the Problems The present inventor has conducted extensive studies to obtain a synthetic polymer compound which is excellent in heat resistance, can be easily produced in a short time, and is excellent in biodegradability. The present invention was completed by crosslinking a high molecular weight polycaprolactone having excellent properties and a polyurethane elastomer.

That is, the present invention is: 1) A crosslinked body of a polymer composition obtained by crosslinking a high molecular weight polycaprolactone and a polyurethane elastomer with an isocyanate catalyst. 2) A method for producing a crosslinked polymer composition, which comprises continuously supplying a high molecular weight polycaprolactone, a polyurethane elastomer and an isocyanate catalyst to an extruder for crosslinking. Regarding

The high molecular weight polycaprolactone used in the present invention is obtained by reacting ε-caprolactone with a diol such as ethylene glycol or diethylene glycol in the presence of a catalyst. As a catalyst used in this reaction, an organic tin compound, an organic titanium compound, and an organic tin halide compound are generally used. 0.1 to 5000 ppm of this catalyst is added, and the reaction temperature is 100 to 2
Polymerization at 30 ° C., preferably in an inert gas, gives the high molecular weight polycaprolactone usable in the present invention. This manufacturing method is, for example, Japanese Patent Publication No. 35-189.
No. 35, Japanese Patent Publication No. 35-497, Japanese Patent Publication No. 40-23917
No. 40-257557 and 43-2473
No. 4, JP-B-47-14739, JP-A-56-4972
No. 8 and JP-A-58-611119. The molecular weight of the high molecular weight polycaprolactone used in the present invention is not particularly limited, but those having a number average molecular weight of 1,000 to 200,000 are preferably used, and one type of high molecular weight polycaprolactone may be used, or Two or more kinds of high molecular weight polycaprolactone having different molecular weights may be used.

The polyurethane elastomer used in the present invention comprises a soft segment made of a polymeric polyol, a monomolecular chain extender constituting a hard segment, and a polyisocyanate. Specifically, there are the following types. (1) Adipate-based polyester type: Polyisocyanate addition-polymerized in the presence of a short-chain polyol to an adipate-based ester polyol by a condensation reaction of azopic acid with glycol or triol. (2) Lactone-based polyester type: a polylactone ester polyol obtained by ring-opening polymerization of ε-caprolactone with a polyisocyanate in the presence of a short-chain polyol. (3) Polycarbonate type: Glycol such as propylene glycol or hexamethylene glycol and a carbonate having an active group such as diethyl carbonate, or polycarbonate glycol obtained by reacting phosgene with addition polymerization of polyisocyanate in the presence of a short chain polyol. . (4) Polyether type: Polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran with addition polymerization of polyisocyanate in the presence of short-chain polyol. As the polyurethane elastomer used in the present invention, any of those exemplified above can be used, and one kind of polyurethane elastomer may be used, or two or more kinds of different polyurethane elastomers may be used.

The composition ratio of the high molecular weight polycaprolactone and the polyurethane elastomer is 95/5 to 30/70. If this composition ratio exceeds 95/5, the heat resistance of the obtained copolymer will be insufficient. The composition ratio is 30 /
When it is less than 70, the biodegradability of the obtained copolymer becomes unsatisfactory.

The cross-linking agent used in the present invention is preferably an isocyanate-based cross-linking agent for polyurethane. For example, xylene diisocyanate, triphenylmethane triisocyanate, polymeric MDI and the like. The amount of the crosslinking agent added is not particularly limited, but 0.2 to 0.8 wt% is appropriate with respect to the total amount of the high molecular weight polycaprolactone and the polyurethane elastomer.

The crosslinked product of the present invention is obtained by continuously supplying the above composition to an extruder and kneading and crosslinking. At this time, the kneading polymerization temperature is suitably 130 to 300 ° C. in terms of resin temperature. If it is lower than 130 ° C, the kneading and crosslinking reaction will be insufficient, and if it is higher than 300 ° C, the hue of the crosslinked resin will be poor. The extruder used in the present invention is preferably an extruder having a large L / D and a high kneading property. Residence time in extruder is 1 to 20
Minutes, preferably 3 to 15 minutes.

[0011]

The present invention will be described in more detail with reference to the following examples.

Example 1 50 parts of high molecular weight polycaprolactone (trade name P-787, number average molecular weight 80,000, manufactured by Union Carbide Chemicals & Plastics, USA), polyurethane elastomer (trade name Pandex T-59)
65, Dainippon Ink and Chemicals Inc. lactone polyester type 50 parts and a cross-linking agent (trade name Crossnate EM)
-30, made by Dainichiseika Co., Ltd.) 0.5 in terms of isocyanate
The parts were sample-molded by sample molding 1 and 2 shown below and evaluated. The evaluation results are shown in Table 1 below.

Example 2 Same as Example 1, but the polyurethane elastomer was changed to: Product name Resamine FR1090, Adipate polyester type manufactured by Dainichiseika. The evaluation results are also shown in Table 1.

Comparative Example 1 Same as Example 1, but without the addition of a cross-linking agent. The evaluation results are shown in Table 1. Comparative Example 2 Same as Example 2, but without the addition of crosslinker. The evaluation results are shown in Table 1. Comparative Example 3 Same as Example 1, but no polyurethane elastomer was added. The evaluation results are shown in Table 1.

Sample molding 1, preparation of tensile test piece Brabender (manufactured by HAAKE BUCHLER, RH
50 g of the composition shown in Table 1 was put into EOCORED SYSTEM 40), the temperature was 200 ° C., the rotation speed was 50 rpm, and 10
Kneaded for minutes, heated by press molding (200 ℃, 5
1 min.) And cooled (20 ° C., 3 min) to prepare a 1 mm sheet. This sheet was punched with a JIS No. 2 dumbbell to obtain a test piece for tensile test evaluation. Sample molding 2, preparation of bottles for heat resistance test, etc. The composition of Table 1 was continuously charged into a 50 mm uniaxial extruder (TEM358, manufactured by Toshiba Machine). A crosslinked body of a polymer composition was obtained at an extrusion resin temperature of 200 ° C., a rotation speed of 100 rpm, a discharge rate of 30 kg / hr, and a residence time in the extruder of 6 minutes. Next, the above-mentioned cross-linked product was put into a blow molding machine (manufactured by Japan Steel Works, Nikko Kautech NB3B) and the resin temperature was 160 ° C and the height was about 10c.
m bottle was molded and used as a bottle for heat resistance test evaluation.

The evaluation method is as follows. The tensile test is JIS
It carried out based on K7113. The bottle moldability was evaluated by whether or not a normal bottle was formed in the molding of the sample molding 2 by the blow molding machine. For heat resistance, put the bottle molded by sample molding 2 in an oven at 70 ° C,
After one day, it was evaluated whether the shape was maintained. The biodegradability was evaluated by whether or not the bottle molded by Sample Molding 2 completely disappears in 12 months when buried in soil or 8 months when immersed in seawater by immersing in soil or seawater. The results obtained are summarized in Table 1 below.

[0017]

[Table 1]

[0018]

The crosslinked product obtained by the present invention is excellent in biodegradability and heat resistance, as well as in mechanical strength and moldability. Further, since this crosslinked product can be easily produced in a short time, it can be applied to the fields of medical treatment, agriculture, forestry and fisheries, and industrial materials, and the problem of waste disposal after use can be solved.

Claims (2)

[Claims] 1. A crosslinked body of a polymer composition obtained by crosslinking a high molecular weight polycaprolactone and a polyurethane elastomer with an isocyanate catalyst. 2. A method for producing a crosslinked polymer composition, which comprises continuously supplying a high molecular weight polycaprolactone, a polyurethane elastomer and an isocyanate catalyst to an extruder for crosslinking.