JPH11255926A - Silicone molding and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly bond a polymer to the surface of a silicone substrate at a low cost without being influenced by the shape of a molding and impart functions such as hydrophilicity, antimicrobial properties, easy slipperiness, sustained releasability of substances, cell adhesion, antithrombotic properties, electroconductivity, photosensitvity, adsorptivity and magnetism to the silicone molding by selecting the polymer having required functional properties. SOLUTION: This silicone molding is obtained by covering at least a part of the surface of a silicone substrate through a silane coupling agent with a polymer. The method for producing the silicone molding comprises treating the surface of the silicone substrate, then coating the treated surface thereof with a silane coupling agent having a reactive functional group, thermally drying the coated silane coupling agent and further bonding the polymer thereonto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a molded silicone product and a method for producing the same.

[0002]

2. Description of the Related Art Various adhesive substances and methods have been developed to impart new properties to the surface of molded articles. Good affinity can be obtained when there is an affinity between the adhesive substance and the substance to be adhered, but when the properties are different, it is difficult to adhere, or even if it can be temporarily adhered, the durability is low. The adhesive substance may be peeled off badly. In order to obtain good adhesiveness, a method is generally known in which the surface of a substance to be adhered is subjected to a chemical or physical treatment, and the adhesive substance is adhered thereon. The chemical treatment is a method of modifying the surface mainly using a chemical, and uses an acid, an alkali, an oxidizing agent, or the like. These chemicals have the effect of simply roughening the surface to increase the surface area, and the effect of introducing a specific functional group to the surface. Further, the case where an adhesive or a primer is applied in advance and an adhesive substance is adhered thereon is also included in the chemical treatment. On the other hand, the physical treatment is a method of increasing the surface area by roughening the surface by plasma treatment or ultraviolet treatment, or introducing a specific functional group to the surface.

[0003] In the case of a silicone molded product, especially a molded product having a crosslinked polysiloxane such as silicone rubber, silicone resin, or silicone resin on at least the surface, the surface is inactive and difficult to adhere, or even if it can be adhered. It is generally known that it has poor durability and easily peels off. All of these resins are composed of three-dimensionally cross-linked polydiorganosiloxane, so they do not dissolve in organic solvents, have no active functional groups, and have a smooth surface by molding. Therefore, the affinity with the adhesive substance is very poor. Conversely, utilizing these properties, these resins are applied to the surface of glass or metal in order to improve chemical resistance and adhesion suppression. There are many molded articles having a crosslinked polysiloxane, and many of them use a crosslinked polysiloxane because they require properties specific to silicone resin such as elasticity. In order to change only the surface properties of such molded products, a hydrophilic, antibacterial, lubricious, sustained-release material, cell adhesion is achieved by bonding a polymer compound containing no silicon to the surface of the crosslinked polysiloxane. Techniques for adding added values such as properties, antithrombotic properties, conductivity, photosensitivity, adsorptivity, magnetism, etc., are not yet known.

[0004]

The crosslinked polysiloxane is said to have a high chemical resistance, so that it is difficult to perform a chemical surface treatment for improving the adhesiveness. On the other hand, physical treatments are often expensive and impractical even if there is a possibility of improving the adhesiveness. In addition, when the shape of the molded product is complicated, the physical treatment cannot be uniformly performed on the entire surface. . The only method is to bond a diorganosiloxane monomer such as RTV rubber by polymerizing it on the surface of the silicone resin. This is possible because both the adhesive substance and the substance to be adhered are substances derived from silicon, and have an affinity as compared with the case where other polymers are bonded. This is impossible with other polymers.

In view of the above-mentioned problems of the prior art, the present inventors have inexpensively provided a polymer on the surface of a substrate having at least a crosslinked polysiloxane such as silicone rubber, silicone resin or silicone resin on the surface. Various studies were conducted to obtain a method. As a result, the silicone substrate is surface-treated to hydrolyze the siloxane bond, and a silane coupling agent having a reactive functional group is bonded to the generated reactive functional group, and then a polymer is further adhered thereon. As a result, it has been found that good adhesiveness can be obtained, and the present invention has been achieved. That is, an object of the present invention is to provide a silicone molded product in which a polymer is provided on the surface of a silicone substrate, and a method for producing the same.

[0006]

The present invention has the following configuration to achieve the above object. "(1) A silicone molded product in which at least a part of the surface of the silicone substrate is covered with a polymer via a silane coupling agent. (2) After the surface treatment of the silicone substrate, a silane cup having a reactive functional group A method for producing a silicone molded product, which comprises applying a ring agent, heating and drying, and contacting and heating a polymer thereon. "

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The silicone substrate in the present invention is a substrate having a polysiloxane on at least the surface, and is, for example, a molded article composed of silicone rubber, silicone resin, silicone resin alone, or It is a molded article with a substance applied to the surface. The shape is not particularly limited, and may be a plate, a tube, a sphere, or a complicated shape suitable for the intended use.

The method of surface-treating the silicone substrate is not particularly limited, and may be any method capable of introducing a reactive functional group capable of reacting with the reactive functional group of the silane coupling agent. The reactive functional group refers to an amino group, a carboxyl group, a hydroxyl group, an isocyanate group, an epoxy group, a thiol group, a vinyl group, a haloalkyl group, and the like, and is easily reacted with a silane coupling agent. An isocyanate group, an epoxy group and a haloalkyl group are preferred, and a hydroxyl group is most preferred. Surface treatment includes chemical treatment, plasma treatment, ultraviolet treatment,
Although there are corona treatment, polishing and the like, chemical treatment is preferable in that the surface of a molded article having a complicated shape can be uniformly treated at low cost. The chemical treatment is mainly a method of modifying the surface using a chemical agent, and is preferably a method of cutting a covalent bond between polysiloxane and silicon-oxygen. As chemicals, for example, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, hydrochloric acid, perchloric acid, phosphoric acid, acids such as oxalic acid, sodium hydroxide,
Potassium hydroxide, ammonia, hydrazine, amine compounds, alkoxide compounds, alkalis such as Grignard reagents, and oxidizing agents such as permanganic acid, dichromic acid, hypochlorous acid, and hydrogen peroxide are used. When a hydroxyl group is introduced as a reactive functional group, sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide are preferably used, and sulfuric acid is particularly preferred. When treating silicone molded products with these chemicals, the concentration of the chemicals in the chemical solution is determined by the degree of crosslinking of the polysiloxane on the silicone substrate, the reaction temperature and the reaction time. When the degree of crosslinking is low, if the concentration of the chemical is too high, the decomposition proceeds excessively and the strength of the silicone base material deteriorates. Therefore, treatment at a low chemical concentration of about 0.001 to 30% by weight at low temperature and for a long time Is preferred. on the other hand,
When the degree of crosslinking is high, if the concentration of the chemical is too low, the decomposition is difficult to proceed. Therefore, it is preferable to perform the treatment at a high chemical concentration of 60 to 100% by weight at a high temperature for a short time.

After surface treatment with a chemical, it is preferable to wash off the chemical with a large amount of water or an organic solvent. After washing, drying may be performed. However, if drying is performed too much, bonding between the cut silicon and oxygen is caused again, and thus drying is not particularly necessary.

A silane coupling agent having a reactive functional group refers to a silane coupling agent having a reactive functional group capable of reacting with a reactive functional group obtained by subjecting a silicone substrate to a surface treatment and capable of reacting with a polymer. It is necessary to have a reactive functional group. Examples of such a reactive functional group include an alkoxy group, an amino group, a carboxyl group, a hydroxyl group, an epoxy group, an isocyanate group, a thiol group, a vinyl group, and a haloalkyl group. The silane coupling agent is selected depending on the reactive functional group present on the surface of the silicone substrate and the reactive functional group present on the polymer. The polymer is an epoxy group, an isocyanate group, a haloalkyl group,
A compound having an amino group having high reactivity is particularly preferable when the base is easily attacked by an ester bond or a urethane bond. When the polymer has a highly reactive group such as an amino group, a hydroxyl group or a thiol group, a coupling agent having an epoxy group or an isocyanate group is preferable.
The amount of the reactive functional group in the coupling agent is preferably 1 to 3 mol of the reactive functional group per 1 mol of silicon, and more preferably 1 to 3 mol.
Molar is preferred.

The silane coupling agent is preferably used by dissolving it in a solvent, and particularly preferably an organic solvent, in order to apply the silane coupling agent uniformly to the surface of the silicone molded product. As the organic solvent, tetrahydrofuran, acetone, methyl ethyl ketone, methanol, ethanol, propanol, ethyl acetate, methyl acetate, benzene, toluene, n-hexane, chloroform, diethyl ether and the like are used. The concentration of the coupling agent in these solvents is 0.001 to 100 because effective coating is difficult to obtain if the concentration is too low.
%, Preferably 0.01 to 20% by weight, more preferably 0.1 to 5% by weight.

After the treatment with the silane coupling agent, it is preferable to evaporate the organic solvent and heat it in order to immobilize the coupling agent on the surface of the silicone substrate. In particular, the alkoxy group of the coupling agent is hydrolyzed. Heating under wet conditions is preferred for decomposition.

The polymer is not particularly limited, and may be a vinyl resin, an epoxy resin, a phenoxy resin, an acrylic resin,
Polyurethane, polyamide, polyester, natural rubber,
Various copolymers and mixtures such as synthetic rubbers, copolymers of these polymers, mixtures of these polymers, and mixtures of these polymers with plasticizers and stabilizers can also be used. In the case of a copolymer, the polymerization form is various and may be any of random, block and graft. Further, in order to be able to react with the reactive functional group in the coupling agent, a reactive functional group such as an amino group, a carboxyl group, a hydroxyl group, an epoxy group, an isocyanate group, a thiol group, a vinyl group, a haloalkyl group, ,
It preferably has at least one reactive bond such as an ester bond, a urethane bond, and an amide bond. When the silane coupling agent contains an amino group, it is preferable to contact a polymer having at least one of an epoxy group, an isocyanate group, a haloalkyl group, an ester bond, and a urethane bond.

The contact form of the polymer may be any of adhesion, welding and fusion, but adhesion is most preferable. The method of bonding may be any method, and includes, for example, a method of applying the polymer after dissolving it in a solvent, a method of pressing the polymer, and the like, and is not particularly limited. When applying a polymer, a solution in which the polymer is dissolved in an organic solvent is used. As the organic solvent, for example, tetrahydrofuran, acetone, methyl ethyl ketone, methanol, ethanol, propanol, ethyl acetate, methyl acetate, benzene, toluene, n-hexane, chloroform, diethyl ether and the like are used. If the viscosity of the polymer solution is too high, uniform coating tends to be difficult to obtain, so that the viscosity when dissolved in a solvent at a concentration of 0.5 to 20% by weight, more preferably 1 to 10% by weight, is 50P or less. It is preferable that the content is 0.01 P or more and 10 P or less.

After the polymer has been attached, it is preferable to evaporate and dry the organic solvent, if necessary, and then heat it in order to bond the reactive functional group of the coupling agent with the polymer.

The step of adhering the polymer is not limited to one time. That is, after the polymer is brought into contact with another polymer, another polymer can be further bonded thereon, and there is no limitation on the type of the polymer to be bonded or the number of times of bonding. If the polymer itself has functionality, it only needs to be adhered once, but if the functional polymer has no reactive functional groups or reactive bonds, it will have an affinity with the functional polymer. It is preferable that a polymer having reactivity and a reactive functional group or a reactive bond is adhered as a primer, and a functional polymer is adhered thereon. Functionality includes, for example, hydrophilicity, antibacterial properties, lubricity, sustained release of substances, cell adhesion, antithrombotic properties, conductivity, photosensitivity, adsorptivity, magnetism, and the like.

The thickness of the polymer layer after contacting and heating the polymer varies depending on the application and is not particularly limited. If it is too thin, it is difficult to exert the function and the effect as a primer. Etc. may be impaired. Therefore, the thickness is 0.01μm
As mentioned above, the range of 1 cm or less is preferable.

The present invention can be applied to any silicone molded article. In particular, silicone rubber and silicone resin are often used in catheters and other molded articles for medical use to suppress the attachment of biological substances. Functionality such as lubricity and antibacterial properties can be imparted. Also, the present invention is not limited to the shape of a silicone molded product, and for example, a tubular molded product such as a catheter can be applied not only to the outer surface but also to the inner surface.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

[0020]

Example 1 120 g of polyvinyl chloride having a degree of polymerization of 550 was dissolved in 2 liters of dimethylformamide, and 2.704 g of sodium salt of diethyldithiocarbamic acid was added. The mixture was reacted at 50 ° C. for 3 hours.
After reprecipitation in methanol, drying was performed to obtain a photograft-activated polyvinyl chloride (hereinafter abbreviated as DTC-modified polyvinyl chloride).

80 g of this DTC-modified polyvinyl chloride is dissolved in 1250 ml of tetrahydrofuran, and 200 g of methoxypolyethylene glycol methacrylate (polymerization degree of polyethylene glycol portion is 20 to 23) and 80 g of dimethylaminoethyl methacrylate are added. In the photoreactor
Photograft polymerization was performed by irradiating a 100W high pressure mercury lamp (USHIO UM-102) at 30 ° C for 9.5 hours. The composition of this graft copolymer was 54% by weight of vinyl chloride, 30% by weight of methoxypolyethylene glycol methacrylate, and 16% by weight of dimethylaminoethyl methacrylate.

After dissolving 5 g of the graft copolymer in 50 ml of N, N-dimethylformamide, 2.4 ml of lauryl bromide is added.
The reaction was performed at 80 ° C. for 16 hours. After throwing into a water-methanol mixture to precipitate, the precipitate was dried. After dissolving in a mixed solution of tetrahydrofuran-methylethylketone and throwing it into hexane for precipitation, the precipitate was dried to obtain an antibacterial material having a quaternary ammonium group containing a long-chain alkyl group (12 carbon atoms).

After wiping the silicone rubber catheter with alcohol cotton to remove dirt, it is immersed in an 80% aqueous sulfuric acid solution at 25 ° C.
Soaked for 1 minute and stirred the solution. Immerse in a large amount of water,
After removing the sulfuric acid, it was immersed in a 1.5% solution of N-β (aminoethyl) γ-aminopropyltrimethoxysilane in tetrahydrofuran at 25 ° C. for 1 minute, dried at room temperature, and dried at 100 ° C. for 1 minute.
Heated for hours. It was immersed in a 3% polyurethane solution in tetrahydrofuran, dried at room temperature, and then heat-treated at 100 ° C. for 1 hour. It was immersed in a 5% by weight mixed solution of the bacterial polymer obtained above in tetrahydrofuran-methylethylketone, dried at room temperature, and washed with water.

After heating the coated silicone tube in hot water at 70 ° C. for 3 hours, the surface of the tube was rubbed with a fingernail. The application of the tube was not peeled off. FIG. 1 shows the result of observing the surface at a magnification of 20 times using a microscope manufactured by KEYENCE.

Further, the obtained coated silicone tube (2 cm) was placed in 2 × 10 ⁴ CFU / ml of S. epidermis.
dis ATCC35984), and immersed in PBS at 37 ° C. for 24 hours. After washing the tubes, they were rolled on an agar medium to transfer the adherent bacteria, and after culturing the medium, the number of colonies was counted. As a result, the number of adherent bacteria was 5 CFU.

The same experiment was carried out for an uncoated silicone tube. As a result, the number of adherent bacteria was 1972 CFU.

Comparative Example 1 A silicone rubber catheter was wiped with an alcohol swab to remove dirt, immersed in a mixed solution of 5% antibacterial polymer in tetrahydrofuran-methylethylketone, dried at room temperature, and washed with water.

After heating the prepared coated silicone tube in 70 ° C. hot water for 3 hours, the surface of the tube was rubbed with a fingernail, and the application of the tube was easily peeled off. FIG. 2 shows the results of observing the surface at a magnification of 20 times using a microscope manufactured by KEYENCE.

Comparative Example 2 A silicone rubber catheter was wiped with an alcohol swab to remove dirt, then immersed in an 80% aqueous sulfuric acid solution at 25 ° C. for 1 minute, and the solution was stirred. It was immersed in a large amount of water to remove sulfuric acid, and then dried. It was immersed in a mixed solution of 5% antibacterial polymer in tetrahydrofuran-methylethylketone, dried at room temperature, and washed with water.

After heating the coated silicone tube in hot water at 70 ° C. for 3 hours, the tube surface was rubbed with a fingernail, and the tube was easily peeled off. FIG. 3 shows the results of observing the surface at a magnification of 20 times using a microscope manufactured by KEYENCE.

Comparative Example 3 A silicone rubber catheter was wiped with alcohol cotton to remove dirt, and then dipped in a 1.5% N-β (aminoethyl) γ-aminopropyltrimethoxysilane solution in tetrahydrofuran at 25 ° C. for 1 minute. Dry at room temperature. It was immersed in a mixed solution of 5% antibacterial polymer in tetrahydrofuran-methylethylketone, dried at room temperature, and washed with water.

After heating the prepared coated silicone tube in 70 ° C. hot water for 3 hours, the surface of the tube was rubbed with a fingernail, and the application of the tube was easily peeled off. FIG. 4 shows the results of observing the surface at a magnification of 20 times using a microscope manufactured by KEYENCE.

[0033]

According to the present invention, it becomes possible to adhere a polymer to the surface of a silicone substrate. According to the present invention, a polymer can be uniformly and inexpensively bonded to the surface of a substrate without being affected by the shape of the substrate. By selecting a polymer with the required functionality, it is possible to add hydrophilicity, antibacterial properties, lubricity, sustained release of substances, cell adhesion, antithrombotic properties, conductivity, photosensitivity, and adsorptivity to silicone substrates. And functions such as magnetism.

[Brief description of the drawings]

FIG. 1 is a photograph showing a surface state of a tube obtained in Example 1.

FIG. 2 is a photograph showing a surface state of a tube obtained in Comparative Example 1.

FIG. 3 is a photograph showing a surface state of a tube obtained in Comparative Example 2.

FIG. 4 is a photograph showing a surface state of a tube obtained in Comparative Example 3.

Claims (20)

[Claims] 1. The method according to claim 1, wherein at least a part of the surface of the silicone substrate is
Silicone molded product covered with polymer via silane coupling agent. 2. The polymer is a vinyl resin, an epoxy resin, a phenoxy resin, an acrylic resin, a polyurethane,
The silicone molded product according to claim 1, wherein the molded product is at least one selected from polyamide, polyester, natural rubber, and synthetic rubber. 3. The silicone molded article according to claim 1, wherein said polymer has a thickness of 0.01 μm or more and 1 cm or less. 4. The polymer according to claim 1, wherein the polymer is hydrophilic, antibacterial, slippery,
The substance according to any one of claims 1 to 3, wherein the substance has at least one function selected from the group consisting of sustained release of a substance, cell adhesion, antithrombotic properties, conductivity, photosensitivity, adsorptivity and magnetism. The molded silicone product as described. 5. The silicone molded article according to claim 1, wherein said molded article is a medical molded article. 6. The silicone molded article according to claim 1, wherein said molded article is a catheter. 7. A silicone molding, characterized in that after a silicone substrate is surface-treated, a silane coupling agent having a reactive functional group is applied, heated and dried, and further contacted with a polymer and heated. Product manufacturing method. 8. A method for producing a silicone molded product, wherein the method of contacting the polymer is a method of applying the polymer solution. 9. The method for producing a silicone molded article according to claim 7, wherein said surface treatment is a chemical treatment. 10. The method for producing a silicone molded article according to claim 7, wherein said surface treatment involves hydrolysis of a siloxane bond. 11. The chemical agent may be sulfuric acid, sulfurous acid, nitric acid, nitrous acid, hydrochloric acid, perchloric acid, phosphoric acid, oxalic acid, permanganic acid, dichromic acid, hypochlorous acid, hydrogen peroxide, hydroxylic acid. 11. The compound according to claim 9, which is at least one selected from sodium, potassium hydroxide, ammonia, hydrazine, an amine compound, an alkoxide compound and a Grignard reagent.
A method for producing the silicone molded product according to the above. 12. The method for producing a silicone molded product according to claim 9, wherein said chemical treatment is performed with a solution having a concentration of 0.001 to 100% by weight. 13. The method according to claim 13, wherein said reactive functional group is at least one functional group selected from an amino group, a carboxyl group, a hydroxyl group, an epoxy group, an isocyanate group, a thiol group, a vinyl group and a haloalkyl group. A method for producing a silicone molded product according to any one of claims 9 to 12. 14. The silicone according to claim 7, wherein the silane coupling agent having a reactive functional group is used as a solution having a concentration of 0.001 to 100% by weight using an organic solvent. Manufacturing method of molded products. 15. The method according to claim 7, wherein the polymer is at least one selected from vinyl resins, epoxy resins, phenoxy resins, acrylic resins, polyurethanes, polyamides, polyesters, natural rubbers and synthetic rubbers. 15. The method for producing a silicone molded product according to any one of items 14 to 14. 16. The solution according to claim 7, wherein the polymer has a viscosity of 0.01 P or more and 50 P or less when the polymer is dissolved in an organic solvent at a concentration of 0.5 to 20% by weight. Production method of silicone molded products. 17. The silicone molded article according to claim 7, wherein the thickness of the polymer layer after contacting and heating the polymer is 0.01 μm or more and 1 cm or less. Method. 18. The polymer has at least one function selected from the group consisting of hydrophilicity, antibacterial properties, lubricity, sustained release of a substance, cell adhesion, antithrombotic properties, conductivity, photosensitivity, adsorptivity and magnetism. The method for producing a silicone molded product according to any one of claims 7 to 17, comprising: 19. The method for producing a silicone molded article according to claim 7, wherein said molded article is a medical molded article. 20. The method for producing a silicone molded article according to claim 7, wherein said molded article is a catheter.