JPWO2020134758A5 - - Google Patents

Description

TECHNICAL FIELD The present invention belongs to the technical field of medical silicone rubber with high mechanical properties, its preparation method, and polymeric materials.

Silicone rubber is one of the most important products among organosilicon materials. Silicone rubber is mainly composed of linear polysiloxane (also called base rubber, raw rubber), reinforcing filler, cross-linking agent, catalyst and other additives. By uniformly mixing all the ingredients, it can be processed into a rubber compound, and under certain conditions, the rubber compound will crosslink (also called vulcanization, curing) and move from the initial high viscosity plastic state to an elastic state. to obtain a vulcanized rubber with a three-dimensional network crosslinked structure.

As is well known, silicone rubber has many properties such as heat resistance, cold resistance, aging resistance (such as ozone aging resistance, thermooxygen aging resistance, photoaging resistance, and climatic aging resistance), electrical insulation and special surface properties. It has excellent properties. Since silicone rubber has excellent performance that ordinary rubber does not have, since its synthesis was successful in 1945, silicone rubber has rapidly developed in basic research and applied fields, and is now used in aerospace, transportation, automobiles, chemical industry, electronics. It is widely used in electrical, construction, medical and other national economic fields, making it an irreplaceable advanced material. However, compared with ordinary rubber, current general-purpose silicone rubber has poor mechanical properties and low strength, which limits the application range of silicone rubber to some extent. Therefore, how to effectively improve the mechanical properties of silicone rubber and obtain silicone rubber that meets practical application needs is always an important research topic in the field of silicone rubber.

Chinese patent CN107868477 discloses a two-component polyurethane-modified liquid silicone rubber and its preparation method, said two-component polyurethane-modified liquid silicone rubber comprises A component and B component, said A component is amino silicone oil and filler in a certain proportion The B component is composed of a polyurethane oligomer and a catalyst in a certain ratio, and the polyurethane oligomer is obtained by a polymerization reaction of a polyol, a prepolymerization catalyst and an isocyanate, and when used, the A component and the B component should be mixed at a constant ratio. The two-component polyurethane-modified liquid silicone rubber obtained by this method has improved mechanical properties due to the presence of polyurethane. low and poor mechanical properties. In the present invention, silicone rubber and polyurethane form a three-dimensional network structure through chemical cross-linking of carbon-carbon bonds, and the mechanical properties are relatively strong.

Chinese patent CN104650591A discloses a method for preparing a polyurethane rubber/silicone rubber compound, which is: 1. 100 parts of white carbon black and 20 parts of hexamethyldisilazane are thoroughly mixed in a mixer and then placed in an oven at 80°C to neutralize. 2. Put the above mixture and 200 parts of methyl vinyl silicone rubber and 10 parts of diphenyl silicone diol into a vacuum kneader and knead to form a rubber compound; 3. Silicone rubber rubber respectively. After mixing the compound and the polyurethane rubber compound on a double roller for 2 minutes, the silicone rubber compound and the polyurethane rubber compound are uniformly mixed at a ratio of 3:2, a vulcanizing agent is added, and the mixture is passed through a sheet. and issuing The method for preparing the polyurethane rubber/silicone rubber compound provided by the present invention is to add white carbon black to raw rubber of methyl vinyl silicone rubber, and after mixing, mix with polyurethane without adding compatibilizer or vulcanizing agent. It is vulcanizable and the resulting rubber compound has excellent mechanical properties. In this method, hexamethyldisilazane was used as a hydrophobizing agent, white carbon black was treated as a filler in rubber compounds, and diphenyl silicone diol was used as a structuring control agent, while methyl vinyl silicone rubber and polyurethane were only vulcanizing agents. In the case of , vulcanization is difficult, and even with heating and vulcanization in the presence of a peroxide vulcanizing agent, the vulcanizate formed has a pungent odor and poor biocompatibility. In the present invention, platinum is used as a vulcanizing agent, and hydrogen-containing silicone oil is dehydrogenated by the catalytic action of platinum to form radicals, thereby causing a radical cross-linking reaction between silicone rubber and polyurethane double bonds. The vulcanized rubber not only has excellent mechanical properties, but also has good biocompatibility and high safety.

It is an object of the present invention to provide a medical silicone rubber with high mechanical properties and a method for its preparation. Compared with conventional silicone rubbers, the silicone rubber of the present invention not only has excellent mechanical properties, but also has good biocompatibility and high safety. It can be widely applied in various fields, especially in the medical field.

The present invention provides a medical silicone rubber with high mechanical properties, which is composed of raw materials of silicone rubber, polyurethane, filler, hydrogen-containing silicone oil, and vulcanizing agent, wherein parts by weight of each raw material are The content of is as follows.

Further, the silicone rubber is one or two of methylvinylsilicone rubber and methylvinylphenylsilicone rubber.

Preferably, the Shore A hardness of the silicone rubber is 10 to 80 degrees.

Further, the polyurethane is a polyester polyurethane or polyether polyurethane containing double bonds.

Furthermore, the polyurethane is a kneading type polyurethane.

Further, the filler is one or more of carboxyl-modified carbon nanotubes, silane-modified white carbon black, vapor-phase white carbon black, precipitated white carbon black, and activated calcium carbonate.

Furthermore, the hydrogen-containing silicone oil is a hydrogen-containing silicone oil containing 1 to 2 wt % of active hydrogen.

Further, the vulcanizing agent is a platinum vulcanizing agent.

The present invention further provides a method for preparing the above medical silicone rubber with high mechanical properties, specifically comprising:
(1) a step of uniformly mixing a portion of filler and silicone rubber in an internal mixer and preparing the remaining filler and polyurethane by uniformly mixing them in an internal mixer;
(2) Mix the mixed polyurethane in an open rubber mixer, then add hydrogen-containing silicone oil, uniformly mixed silicone rubber, and a vulcanizing agent to the open rubber mixer in small amounts several times in sequence, until all After the components are uniformly mixed, pass through thinly three times, and finally vulcanize the rubber compound with a flat rubber vulcanizer at 150-190°C for 5-15 minutes to obtain medical silicone rubber with high mechanical properties. and the step of

Further, in the above preparation method, the mixed polyurethane is uniformly mixed with hydrogen-containing silicone oil, silicone rubber and vulcanizing agent at 40-60°C.

The inventors have unexpectedly discovered that the silicone rubber of the present invention undergoes a cross-linking reaction with polyurethane via a vulcanizing agent, an advantage of which is the dehydrogenation of hydrogen-containing silicone oils using platinum as a vulcanizing agent. to form radicals, thereby causing a radical cross-linking reaction of silicone rubber and polyurethane double bonds, silicone rubber and polyurethane chemically cross-linking via carbon-carbon bonds, forming a three-dimensional network structure, and obtaining The resulting vulcanized rubber has a tear strength of 55 KN/m or more, a tensile strength of 15 MPa or more, and a relatively high mechanical strength. In addition, the resulting medical silicone rubber has no cytotoxicity, delayed hypersensitivity, and intradermal irritation, and has good biocompatibility. spread.

It is a test piece of the medical silicone rubber of the present invention with a thickness of 2 mm and high mechanical properties.

The present invention will now be described in greater detail with reference to examples, which should not be construed as limiting the scope of the present invention. It is evident that those skilled in the art can make some non-essential improvements and adjustments based on the above teachings of the invention.

Each performance of the products obtained in Examples and Comparative Examples was measured using the following standards:
Tensile Strength: GBT 528-2009 Vulcanized Rubber or Thermoplastic Rubber Tensile Stress and Strain Performance Measurement Tear Strength: GBT 529-2008 Vulcanized Rubber or Thermoplastic Rubber )
Cytotoxicity test: GBT 16886.5-2017 In vitro cytotoxicity test Delayed hypersensitivity and intradermal irritation test: GBT 16886.10-2017 Biological evaluation of medical devices Part 10: Irritation and skin sensitization test High mechanical properties preparation of medical silicone rubber

The raw materials and parts by mass of the medical silicone rubbers of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 1 below. wherein the polyurethane is a polyester kneading type polyurethane containing double bonds, the filler is gas phase white carbon black, the hydrogen-containing silicone oil is a hydrogen-containing silicone oil containing 1.5 wt% of active hydrogen, and the The vulcanizing agent is a platinum vulcanizing agent. The preparation method is as follows.

Each raw material is weighed as shown in Table 1, and a portion of the filler and silicone rubber are uniformly mixed in an internal mixer to prepare, and the remaining filler and polyurethane are uniformly mixed in an internal mixer to prepare. Next, the mixed polyurethane is mixed in an open rubber mixer at a mixing temperature of 40 to 60°C. Mix. After all the ingredients are uniformly mixed, thinning is performed three times, and finally the rubber compound is vulcanized in a flat rubber vulcanizer under the vulcanization temperature and time conditions shown in Table 1 to obtain high mechanical properties. Acquire medical silicone rubber.

The mechanical properties of the products obtained in Examples 1-7 and Comparative Examples 1-4 were measured and the results are shown in Table 2.

As shown in Table 2 above, the tear strength of Examples 1 to 7 reaches 55 KN/m or more, the tensile strength reaches 15 MPa or more, and has relatively high mechanical strength. Compared to Examples 1 to 7, Comparative Examples 1 to 4 contain only 5 parts of the filler of Comparative Example 2, and the filler has a reinforcing effect on both the kneading type polyurethane and the silicone rubber, thereby reducing physical winding. In order to perform the action of adhesion and crosslinking, its tensile strength and tear strength are low. In Comparative Example 3, only 1 part of hydrogen-containing silicone oil and 1 part of vulcanizing agent are added, There is no molding, which indicates that silicone rubber and kneading type polyurethane need to reach a certain amount of hydrogen-containing silicone oil and vulcanizing agent to achieve the purpose of co-vulcanization. In Comparative Example 4, the vulcanization conditions of 140° C. and 4 minutes were adopted, but the performance of the resulting vulcanized rubber was poor. This is because the rubber compound was incompletely vulcanized under the above vulcanization conditions. is.

The safety of the products of Examples 1-7 and Comparative Examples 1-4 was measured, and the results are shown in Tables 3 and 4.

As can be seen from Tables 3 and 4, the cytotoxicity test, delayed hypersensitivity reaction and intradermal irritation test of the products of Examples 1-7 all passed, which is the high mechanical property medical silicone rubber of the present invention. indicates good biocompatibility. Intradermal irritation in Comparative Examples 1, 3 and 4 was unsatisfactory, which was due to the excessive addition of kneading type polyurethane in Comparative Example 1, and in Comparative Examples 3 and 4 completely It was not vulcanized.

As described above, the medical silicone rubber with high mechanical properties prepared according to the present invention not only has excellent mechanical properties, but also has the advantage of being non-toxic, non-irritating, and highly safe to the living body. .

The technical features of the above embodiments can be combined arbitrarily, and for the sake of brevity of explanation, not all possible combinations of the technical features in the above embodiments are described. All combinations of these technical features are included in the scope of the present invention unless stated otherwise.

Although the foregoing examples illustrate and detail certain embodiments of the invention, they should not be construed as limitations on the patentable scope of the invention. It is obvious for those skilled in the art that some modifications and improvements can be made without departing from the spirit of the present invention, and all these modifications and improvements are covered by the protection scope of the present invention. Therefore, the patent protection scope of the present invention should be subject to the attached claims.

Claims (7)

Consists of raw materials of 50 to 90 parts by weight of silicone rubber, 10 to 50 parts of polyurethane, 10 to 50 parts of filler, 2 to 6 parts of hydrogen-containing silicone oil, and 2 to 5 parts of platinum vulcanizing agent,
The polyurethane is a polyester polyurethane or polyether polyurethane containing double bonds,
A portion of the filler and silicone rubber are evenly mixed in an internal mixer, the remaining filler and polyurethane are uniformly mixed in an internal mixer, the mixed polyurethane is mixed in an open rubber mixer, and then put into the open rubber mixer. , Hydrogen-containing silicone oil, uniformly mixed silicone rubber, and platinum vulcanizing agent are sequentially added in small amounts several times. and finally vulcanizing the rubber compound in a flat rubber vulcanizer at 150 to 190° C. for 5 to 15 minutes, whereby the silicone rubber and the polyurethane are chemically crosslinked. Biocompatible silicone rubber for medical use with special properties. The biocompatible silicone rubber for medical use with high mechanical properties according to claim 1, characterized in that said silicone rubber is one or two of methylvinylsilicone rubber and methylvinylphenylsilicone rubber. The biocompatible silicone rubber for medical use with high mechanical properties according to claim 1, characterized in that said silicone rubber has a Shore A hardness of 10 to 80 degrees. The biocompatible silicone rubber for medical use with high mechanical properties according to claim 1, characterized in that said polyurethane is a kneading type polyurethane. 2. The high density filler of claim 1, wherein the filler is one or more of carboxyl-modified carbon nanotubes, silane-modified white carbon black, vapor-phase white carbon black, precipitated white carbon black, and activated calcium carbonate. Biocompatible silicone rubber for medical use with mechanical properties. The biocompatible silicone rubber for medical use with high mechanical properties according to claim 1, characterized in that said hydrogen-containing silicone oil is a hydrogen-containing silicone oil containing 1-2 wt% of active hydrogen. A method for preparing biocompatible silicone rubber for medical use with high mechanical properties according to any one of claims 1 to 6, specifically comprising:
(1) a step of uniformly mixing a portion of filler and silicone rubber in an internal mixer and preparing the remaining filler and polyurethane by uniformly mixing them in an internal mixer;
(2) After mixing the mixed polyurethane in an open rubber mixer at 40 to 60° C. , hydrogen-containing silicone oil, uniformly mixed silicone rubber, and platinum vulcanizing agent are sequentially added in the open rubber mixer. A small amount was added several times, and after all the ingredients were uniformly mixed, the silicone was passed through three times, and finally the rubber compound was vulcanized with a flat rubber vulcanizer at 150 to 190°C for 5 to 15 minutes. chemical cross-linking reaction of rubber with said polyurethane to obtain biocompatible silicone rubber for medical use with high mechanical properties.