JPS60247556A - Composite molded shape of silicone rubber and olefin group resin and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite molded product of silicone rubber and an olefin resin, mainly an ethylene resin, and a method for producing the same.

[Prior art]

In general, olefin resins, particularly polyethylene, polypropylene, and ethylene-propylene copolymers, are inexpensive and have excellent toughness and rigidity, and are widely used as packaging materials and medical materials. However, since these olefin resins are non-polar crystalline resins and hardly dissolve in solvents, they have been considered extremely difficult to adhere to metals and plastics.

Therefore, in the past, physical treatments such as corona discharge treatment or chemical treatments such as dichromic acid-sulfuric acid mixture were used to oxidize the surface to generate an oxide film containing polar groups such as carbonyl groups. Products are made of epoxy-polyamide, nitrile rubber, isocyanate,
Seventy-five attempts have been made to bond with cyanoac 1-root adhesives, etc., but in either case, there are very few that have achieved sufficient adhesive strength for practical use. Furthermore, even if the olefin resin surface-treated in this way is coated with another resin diluted with ml of solution, in most cases it is easily peeled off and it is difficult to integrate the resin into a composite.

[Purpose of the invention]

The purpose of the present invention is to combine olefin resins, which are low in price but have excellent toughness and rigidity and are widely used as medical devices and packaging materials, and silicone rubber, which is high in price and lack strength but has excellent biocompatibility. The object of the present invention is to provide a material that is useful mainly for medical purposes or industrial applications, and is durable and does not peel off even when subjected to hot water or autoclave treatment.

[Structure of the invention]

The present inventors have previously proposed in Japanese Patent Application No. 58-203699, etc., that by applying an addition-polymerizable liquid silicone rubber of a certain specific formulation to a soft vinyl chloride resin of a certain specific formulation and heating it, both However, when we investigated whether this method could be applied to olefin resins as well, we found that the addition polymerization method can also be applied to olefin resins, which have traditionally been considered to have extremely poor adhesive properties. The inventors discovered that liquid silicone rubber adheres strongly when cured by heat, and after extensive research, they have completed the present invention.

That is, the present invention relates to a composite molded product of silicone rubber and an olefin resin, mainly an ethylene resin, and a method for manufacturing the same.

The addition polymerization type liquid silicone rubber in the present invention is composed of a vinyl group-containing polysiloxane represented by the general formula (2), an organohydrogen polysiloxane represented by the general formula (3), and a platinum-based catalyst. Accordingly, silica or the like is added as a reinforcing material, and it can be hardened into a rubber-like state by heating. More preferably, compared to the total number of vinyl groups present in the addition polymerizable liquid silicone rubber, hydrogen atoms directly bonded to silicon atoms are added in excess to the extent that the physical properties after curing are not significantly impaired. An organohydrogenpolysiloxane having two or more hydrogen atoms in one molecule is contained in an amount sufficient to provide hydrogen atoms directly bonded to silicon atoms at a ratio of 1 to 6 times the total vinyl groups. It is preferable.

In addition, among the components generally referred to as self-adhesive silicone rubber, epoxy compounds, carboxylic acid anhydrides, xane represented by the general formula (4), or oxirane compounds containing unsaturated hydrocarbon groups, -S or more, the organohydrogen siloxane units shown in general formula (3) are directly bonded to silicon atoms at a ratio of 1 to 6 times the total vinyl groups shown in general formula (2). If an organohydrogen polysiloxane having two or more hydrogen atoms in one molecule is contained in a sufficient amount to provide hydrogen atoms, a similar adhesive effect can be obtained, and the above-mentioned components for improving adhesiveness can be obtained. Although not essential, it is preferable that it be added.

O In the present invention, olefin resins include low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α-olefin copolymer, polypropylene, ethylene-propylene block copolymer, Ethylene copolymer such as ethylene-propylene random copolymer, ethylene-propylene-diene terpolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, saponified ethylene-vinyl alcohol copolymer, etc. It is a single polymer selected from polymers, ionomer resins, polybutadiene and butadiene copolymers, etc., or a mixture of two or more of them, or a mixture of these and thermoplastic resins other than the above, and contains no inorganic molecules in the molecule. Those containing a relatively large amount of saturated double bonds are preferred. For example, polyethylene originally has a linear molecular structure of CH2 as shown in formula (5), but depending on the polymerization conditions etc. Unsaturated double bonds as shown in the formula are often formed in the molecular chain, and it is well known that even in the case of high-density polyethylene, terminal vinyl groups have been confirmed from infrared spectroscopy. It is preferable that many unsaturated double bonds remain.

When applying addition polymerization type liquid silicone rubber ft to the surface of an olefin resin molded article containing such unsaturated double bonds, the number of vinyl groups directly bonded to silicon atoms is smaller than the total number of vinyl groups in the addition polymerization type liquid silicone rubber. Contains an organohydrogenpolysiloxane having two or more hydrogen atoms in one molecule, in an amount sufficient to provide approximately the same number of hydrogen atoms or in excess to the extent that the physical properties after curing are not extremely impaired. If so, a composite molded article in which the olefin resin and the addition type silicone rubber are strongly bonded and integrated by heating can be obtained.

The adhesion mechanism in the present invention is basically the adhesion between soft vinyl chloride resin and silicone rubber, as estimated in Japanese Patent Application No. 58-203699, an earlier patent filed by the present inventors. It is thought that the mechanism is almost the same. In other words, it is assumed that this is due to the addition reaction of the hydrosilyl group of the methylhydrogen polysiloxane in the addition-polymerized liquid silicone rubber to the unsaturated double bonds present in the olefin resin. The adhesion is extremely strong because it is not adhesion based on introduction, but uses an addition reaction.

The additives added to the olefin resin in the present invention are not particularly limited, but include BI as an antioxidant.
T, phosphite esters, mercaptan compounds, organic disulfide compounds, or organic tin compounds as light stabilizers tend to inhibit the addition reaction in the present invention, so please avoid using them. In this case, it is preferable to reduce the amount added as much as possible.

The method for producing a composite molded product of silicone rubber and olefin resin in the present invention is not particularly limited, but may be performed by dissolving an addition polymerization type liquid silicone rubber or a nucleation polymerization type liquid silicone rubber in a solvent such as toluene or hexane. The solution was applied to the surface of a pre-formed olefin resin molded product.
It is coated by a dipping method, a spray method, or the like, and heated at 40 to 130° C., preferably the highest temperature that does not cause thermal deformation in practical use, for 3 minutes to 5 hours, preferably 0 minutes to 2 hours.

In the composite molded product on silicone rubber and olefin resin of the present invention, the thicker the silicone rubber layer, the stronger the adhesive force with the olefin resin, which is at least 10 μm.
As mentioned above, if it is preferably 50μ or more, there is no fear of peeling in practice, but if it is 10μ or less, peeling may occur.

Among the olefin resins used in the present invention, polypropylene homopolymer has the lowest adhesiveness among olefin resins because it has extremely few unsaturated double bonds; A certain degree of adhesion is possible by using rubber, and in addition, a propylene-ethylene copolymer, especially a block copolymer, containing an ethylene moiety of only about 5% F is used, or a polyethylene content of about 5% F is used. By blending, the adhesion with addition polymerization type liquid silicone rubber can be further improved.

The composite molded product of olefin resin and silicone according to the present invention is widely used in the medical field, for example, for cannulas, blood-related medical devices such as vascular catheters, and urinary-related medical devices such as ureteral catheters. Can be widely applied,
To provide an excellent composite molded product that combines the antithrombotic properties and tissue compatibility of silicone with the toughness and stiffness of olefin thread resin.

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Low density polyethylene (F-208 manufactured by Sumitomo Chemical Co., Ltd.),
FS-1012) was extruded into a sheet with a thickness of 08% using a 40% ρ extruder, and each sheet was 2 cm x 5.
I cut it into two pieces each to the desired size.

On the other hand, a silicone rubber containing 12 mot% of trimethyloctasiloxy units and dimethylsiloxy units was prepared based on 100 parts of dimethylpolysiloxane having a viscosity of 12.0OOC8 at 25°C and a vinyl dimethylsilyl group at the end of the molecular chain. This addition-polymerizable liquid silicone rubber was sandwiched between the various olefin resins mentioned above so that the thickness was 1% and the contact area was 20% (top and bottom) x approximately 25%, and heated in a constant temperature bath at 110°C for 90 minutes. .

Furthermore, as comparative examples, commercially available addition polymerization type liquid silicone rubber (KE-1910 manufactured by Shin-Etsu Chemical Co., Ltd.) and condensation type RTv silicone rubber (KE-42 manufactured by Shin-Etsu Chemical Co., Ltd.) were used.
RTV) was used in the same manner.

The thus obtained test piece was subjected to a 1806 peel test at room temperature to measure the adhesive strength. The results are shown in Table 1), and it can be seen that the composite molded product of the addition polymerization type silicone rubber and olefin resin according to the present invention is strongly adhesively integrated.

Table 1 Adhesive strength between olefin resin and silicone rubber (kLi/1011+1) *1 F-208 manufactured by Sumitomo Chemical *2 FL6315 manufactured by Sumitomo Chemical *3 FS-1012 manufactured by Sumitomo Chemical *4 Shin-Etsu Chemical KE-1g10 made by Kogyo ■5 KF, -42RTV made by Shin-Etsu Chemical Co., Ltd. (Note) ◎ indicates cohesive failure of the silicone layer Example 2 Low-density polyethylene (FIOI made by Susumu Chemical Co., Ltd.),
It was extruded into a tube shape with an inner diameter of 5% and an outer diameter of 6~ using a 40% V extruder, and cut into a length of about 50 cWL.

On the other hand, a methylhydrogen polysiloxane weight % solution having a viscosity of 1500C8 at 25°C and a known viscosity of 60C8 was prepared. The low-density polyethylene tube was dipped in this solution, air-dried for 10 minutes, and then
It was heated in a constant temperature bath at ℃ for about 2 hours.

Thereafter, the tube was taken out and observed, and it was found that the low-density polyethylene and silicone rubber were firmly bonded and integrated on both the inner and outer surfaces of the tube.

The thus obtained tube and the above-mentioned low-density polyethylene tube without coating were prepared for comparison and cut into three lengths each. One end of each was clamped, and 0.5 ml of dog ACD fresh blood was accurately weighed and injected into it, followed by 0.05 ml of 0.8 wt% calcium chloride aqueous solution was accurately weighed and injected. After stirring lightly with a microspertyl, the other end was clamped.

These tubes were placed in a constant temperature bath at 37°C for a specified period of time, then immersed in 100 cc of distilled water to remove the insolubilized blood clots, fixed with a 37% by weight aqueous formalin solution, washed again with water, and then dried. Their weight was measured.

The results are shown in Table 2.

Table 2 Blood clot weight after blood coagulation reaction (■) [Effects of the invention] As described above, the composite tube of the present invention is strongly integrated into a composite, strong and highly rigid, and has a smooth surface. Vascular catheter with high elasticity and excellent antithrombotic properties,
It is clear that the tube is extremely suitable for ureteral catheters and the like.

Patent Applicant: Sumitomo Bakelite Co., Ltd. Hatashi System-rk System: Macahachi Kune L Page 1 continued 0 Inventor: Akira Shiba 1) Masaru @ Inventor: Igarashi Akira @ Inventor: Kawaguchi Beidai 1-2 Uchisaiwai-cho, Chiyoda-ku, Tokyo No. 2 Sumitomo Bakelite Hama Factory

Claims (6)

[Claims] (1) A composite molded product of silicone rubber and olefin resin, in which a cured layer of addition polymerized silicone rubber is provided on the surface of an olefin resin molded product. (2) The addition polymerizable silicone rubber has one hydrogen atom directly bonded to a silicon atom per vinyl group in the composition.
The silicone rubber according to claim (1), characterized in that it contains an organohydrous bulk polysiloxane having two or more hydrogen atoms in one molecule in an amount sufficient to provide 1 to 6 hydrogen atoms. Composite molded product with olefin resin. (3) The addition-polymerizable silicone rubber contains an epoxy compound, a carboxylic acid anhydride, a silane or siloxane containing acryloxyalhelyl group as shown in the general formula (1) as a component for improving adhesiveness, or A composite molded product of silicone rubber and olefin resin according to claim (1), which is a silicone composition containing at least one kind of oxirane compounds containing unsaturated hydrocarbons. . (4) The olefin resin is polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer, ethylene-propylene-diene terpolymer, ethylene-vinyl acetate copolymer, ethylene-
One or a mixture of two or more selected from vinyl alcohol copolymers, ethylene copolymers such as saponified ethylene-vinyl alcohol copolymers, ionomer resins, polybutadiene, and butadiene copolymers. A composite molded product of silicone rubber and olefin resin according to claim (1), characterized by: (5) The olefin resin is polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-α-
Ethylene copolymers such as olefin copolymers, ethylene-propylene-diene terpolymers, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, saponified ethylene-vinyl alcohol copolymers, and ionomers The silicone according to claim (1), which is a mixture of one or more selected from resins, polybutadiene, and butadiene copolymers, and a thermoplastic resin other than the above. A composite molded product of rubber and olefin resin. (6) Composite molding of silicone rubber and olefin resin characterized by heating and curing at a temperature of at least 40°C when providing a cured layer of addition polymerized silicone rubber on the surface of the olefin resin molded product. How things are manufactured.