JPH06192494A - Formed article improved in transparency - Google Patents

Abstract

PURPOSE:To obtain an article improved in transparency and antithrombotic properties by kneading an ethylene resin, a specified phenylated organopolysiloxane and an organic peroxide and forming the kneaded material. CONSTITUTION:100 pts.wt. ethylene resin with a density of at most 0.945g/cm<3> is mixed with 10-900 pts.wt. phenylated organopolysiloxane of the formula [wherein R<1> is an aliphatic unsaturated group; R<2> is an (un)substituted univalent hydrocarbon group containing no aliphatic unsaturated group, of which at least 0.1% is phenyl; and 0<=a<=1 and 0.5<b<3, provided that 1<a+b<3] and 0.005-1 pt.wt. organic peroxide having a 10-min half-life temperature of 100-220 deg.C, and the mixture is kneaded by heating at 160 deg.C or higher to give a kneaded material having a gel content of at least 10%. This material is formed into a desired shape to give the title article. If necessary, the surface of the product is treated with an alkali.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a molded article having improved transparency and an antithrombogenic medical article having improved transparency. More specifically, it is a molded product made of a heat-kneaded product composed of an ethylene-based resin and a phenyl group-containing organopolysiloxane. Since these are excellent in transparency and can also impart antithrombotic properties, catheters, artificial blood vessels, Blood collection tubes, blood bags and films that require transparency,
Used as sheets, bottles, pipes, etc.

[0002]

2. Description of the Related Art In recent years, polyvinyl chloride, polypropylene, polystyrene, polyethylene, polyamide, AB
S, polyhydroxyethylmethacrylate, polyurethane, polytetrafluoroethylene, polymethylpentene-
1. Various polymer materials such as styrene-butadiene block copolymer, butyl rubber, silicone rubber are artificial blood vessels, blood bags, infusion bags, syringes, artificial lungs, artificial esophagus, artificial hearts, artificial intestines, artificial ureters, artificial Breast, catheter,
It has come to be used as various medical materials such as contact lenses, artificial joint cartilage, and blood vessel sutures. These polymeric materials have tensile strength, flexibility, flexibility, rubber elasticity, high transparency, radiation resistance, component non-elution, non-toxicity, non-irritancy, non-carcinogenicity, depending on the purpose for which they are used. , Non-mutagenic, non-teratogenic, non-allergic, non-protein denaturing, etc. are required. Furthermore, since most of the above-mentioned medical materials have many opportunities to come into contact with blood, the hemostatic function of blood, that is, thrombus formation when blood comes into contact with a foreign substance occurs, which poses a risk to the maintenance of life. That is, securing of antithrombogenicity has become an important issue.

Conventionally, various methods have been proposed for imparting antithrombogenicity to polymer materials. For example, note that thrombus formation is caused by the blood coagulation system that eventually transforms fibrinogen into insoluble fibrin by a series of complex enzymatic reactions, such as heparin and antitropin III that act as inhibitors of this blood coagulation system enzyme. Of the above-mentioned fibrinolytic system activating enzyme is immobilized on an imide ring-opened product of polyimide, which is a reaction product of 1,2,3,4-butanetetracarboxylic acid and alkyldiamine (JP-A-58-58).
No. 2206), A method of applying urokinase, streptokinase, etc., which dissolves fibrin, which causes thrombus, on the surface of the material (JP-A-52-10378, JP-A-53-79964).
JP-A-53-82900, JP-A-53-8839
No. 0, JP-A-53-106778, JP-A-53-12
0883, JP-A-53-129480, JP-A-54.
No. 79997, JP-A-54-83095), Hydrogels obtained by cross-linking hydrophilic polymers such as poly (2-hydroxyethyl) methacrylate and polyvinyl alcohol (Japanese Patent Publication No. 46-42759, JP-A No. 46-25959). 5
0-150793, JP-A-51-24651), a method of graft-polymerizing the above-mentioned hydrophilic polymer-forming monomer on the surface of a substrate (JP-A-49-125493, JP-A-51-125978). A method of binding a polyalkylene glycol to the surface by treating the surface of a polymer material having a reactive functional group with a polyalkylene glycol solution (JP-A-60)
-96259), a copolymer of polysiloxane and polyurethane (USP
No. 3,562,352), a polyurethane containing an organosilicon polymer in the main chain (JP-A-57-212356), a polymer of (meth) acrylic acid hydrazide or (meth) acrylic acid hydrazide and (meth) ) A hydrophobic polymer having a copolymer with acrylic acid on the surface (Japanese Patent Laid-Open No. 61-8).
No. 7564),-A method of graft-polymerizing a water-soluble monomer on the surface of a base material made of a polymer material (JP-A-62-87163),-For polyolefin or halogenated polyolefin, 2
There is a method of graft polymerizing hydroxyethyl (meth) acrylate (JP-A-62-109575).
However, these conventional ones have high polymer production costs, insufficient antithrombotic properties, poor processability of molded products, insufficient antithrombotic effect persistence, and residual properties. There is a problem with toxicity due to the monomer and plasticity, and it does not satisfy all the conditions as an antithrombotic medical material. In addition, the transparency of molded articles is often insufficient, and for example, in the case of a blood transfusion tube, if it is opaque, it is inconvenient to judge whether blood is flowing or not, and it may affect the life of the patient. A highly transparent material has been demanded.

[0004]

Further, the conventional medical polymer materials are relatively expensive. However, due to the prevention of infectious diseases caused by blood, the shortage of medical workers, etc., and the labor saving by using disposable medical supplies, especially low cost medical polymer materials have recently been required. The present invention is to meet these social requirements, performance required as a medical polymer material (antithrombogenicity, mechanical strength, durability, non-toxic, sterilizable, biocompatible, It is non-irritating, and is capable of relatively simple injection molding, inflation molding, extrusion lamination molding, extrusion tube molding, etc. when molding various medical products, and the material cost is very low, and An object is to provide a highly transparent medical polymer material.

[0005]

Means for Solving the Problems The present inventors have found that polysiloxane polymers have been used as medical polymeric materials for antithrombogenicity, biocompatibility, nontoxicity, organs of human body (blood vessels, trachea, heart). , Heart valve, pericardium, ureter, bladder, diaphragm, bile duct, esophagus, ossicle, eardrum, etc., physical properties, lightness,
Since it is excellent in gas permeability, low friction, water repellency, oil repellency, low temperature resistance, etc., it has been noted that it is used in specific applications, and its antithrombotic property is further improved. If it can solve the problems of lack of physical characteristics, inferior processability, high price, etc., it can dramatically expand the applications and contribute to national medical care. As a result of intensive research, Japanese Patent Application No. 1-328
No. 850, a method for producing an antithrombotic material, which comprises subjecting the surface of a molded article obtained by molding a heat-kneaded product of an ethylene- (meth) acrylic acid copolymer and organopolysiloxy acid to alkali treatment, and I applied for an antithrombotic material obtained by this method. Then, in Japanese Patent Application No. 4-32729, a molded article obtained by heating and kneading an ethylene-vinyl acetate copolymer, an organopolysiloxane, and an organic peroxide has a higher antithrombotic property than a silicone-based single substance. However, since the transparency was insufficient, the present inventors have found that the transparency can be improved by selecting a specific organopolysiloxane, and have completed the present invention.

[0006]

DETAILED DESCRIPTION OF THE INVENTION That is, the present invention comprises (1) 100 parts by weight of an ethylene resin and the following formula (I):

[Chemical 4] (In the formula, R ¹ represents an aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and 0.1% or more of these represents a phenyl group, a and b are the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3), and 10 to 900 parts by weight of a phenyl group-containing organopolysiloxane and an organic peroxide. 0.00
A molded product with improved transparency, which is obtained by molding a kneaded product having a gel content of 10% or more obtained by heating and kneading a resin composition consisting of 5 to 1 part by weight, (2) ethylene- (meth) acrylic acid copolymer 100 parts by weight of polymer, the following formula (I)

[Chemical 5] A resin composition comprising 10 to 900 parts by weight of a phenyl group-containing organopolysiloxane (wherein R ¹ , R ² , a and b are as described above) and 0.005 to 1 part by weight of an organic peroxide. An antithrombogenic medical article with improved transparency obtained by subjecting the surface of a molded product obtained by molding a kneaded product having a gel content of 10% or more obtained by heating and kneading, to (3) ethylene- 100 parts by weight of vinyl acetate copolymer, the following formula (I)

[Chemical 6] A resin composition comprising 10 to 900 parts by weight of a phenyl group-containing organopolysiloxane (wherein R ¹ , R ² , a and b are as described above) and 0.005 to 1 part by weight of an organic peroxide. An antithrombogenic medical device having improved transparency, which is obtained by molding a kneaded product having a gel content of 10% or more obtained by heating and kneading.

In the present invention, the ethylene resin means ethylene alone or ethylene and other α-olefins such as propylene, butene-1,4-methylpentene-.
1, hexene-1, octene-1, nonene-1, decene-1, tetradecene-1, octadecene-1 and the like. Or other unsaturated group-containing monomer such as styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene,
Allylbenzene, butadiene, isoprene, chloroprene, vinyl fluoride, vinyl chloride, vinyl bromide, vinylidene fluoride, vinylidene chloride, vinylidene bromide, tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, dichlorodifluoroethylene, Vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, stearyl acrylate, methyl methacrylate, octyl methacrylate, stearyl methacrylate, methacrylic acid, itaconic acid, methylene glutaric acid, anhydrous Itaconic acid, methyl vinyl ketone, phenyl vinyl ketone, ethyl vinyl ketone, methyl isopropenyl ketone, methyl vinyl ether, ethyl vinyl ether, phenyl vinyl ether,
Vinyl thioether, acrylonitrile, acrylamide, acrylic dimethylamide, dimethylaminoethyl methacrylate, 2-hydroxyethyl acrylate, glycerin methacrylate, glycidyl acrylate, glycidyl methacrylate, allyl acrylate, allyl methacrylate, ethylene glycol diacrylate, divinyl ether, N -Vinylpyrrolidone, N-vinylimidazole, ethylmaleimide, N-vinylphthalimide, vinylpyridine, N-vinylcarbazole, N-vinyl-
N-methylacetamide, N, N-dimethylaminoethyl acrylate, t-butylacrylamide, methacrylamide, t-butylaminoethyl methacrylate, vinyl sulfide, trimethoxyvinylsilane, triethoxyvinylsilane, γ-methacrylopropyltrimethoxysilane, vinyltrichloro It is a resin obtained by copolymerizing silane, diphenylmethylvinylsilane, and the like.

Typical examples are high-pressure polyethylene, linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (VLDPE), ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer (EV).
A), ethylene-ethyl acrylate copolymer (EE
A), ionomers, ethylene-styrene copolymers and the like. However, an ethylene resin having a density of 0.945 or more cannot be used in the present invention because it has poor transparency, adhesiveness, flexibility and the like. When ethylene- (meth) acrylic acid copolymer and ethylene-vinyl acetate copolymer are selected, the antithrombotic property becomes very good.

The organopolysiloxane used in the present invention is represented by [Chemical Formula 1], in which R ¹ group is exemplified by vinyl group, allyl group, acryl group, methacryl group and the like, and R ² is represented by Is a methyl group, an ethyl group, an alkyl group such as a propyl group, an aryl group such as a phenyl group and a tolyl group, a cycloalkyl group such as a cyclohexyl group and a cyclobutyl group, and a hydrogen atom bonded to a carbon atom of these hydrocarbon groups. Examples thereof include a group substituted with a halogen atom, a cyano group, a mercapto group and the like, but it is an essential requirement that 0.1% or more of a phenyl group is contained. 0.
When it is 1% or less, the transparency of the molded product is insufficient, which is not desirable. These groups may be the same or different combinations. In addition, a is 0 or more than 0 and less than 1. When this range is 1 or more, the molded article produced by the method of the present invention becomes too hard. a is preferably 0.0004 to 0.06. b is greater than 0.5 and less than 3. If this range is 0.5 or less, it is difficult to knead the composition in the present invention, and the processability is poor, and if it is 3 or more, the molded product produced by the method of the present invention becomes too hard, which is not desirable. b is preferably 1-2.

The molecular structure of the organopolysiloxane in the present invention may be any of chain, branched chain, ring, net, three-dimensional net, etc. as long as it is represented by the formula (I). Examples of such an organopolysiloxane include so-called silicone gum stock, which is commercially available as a tear strength improver for silicone rubber. Further, the linear organopolysiloxane used in the present invention has a general formula:

[Chemical 7] (In the formula, R represents an unsubstituted or substituted monovalent hydrocarbon group,
n represents a number of 10 or more), and there is one generally called silicone oil.

R in the above formula is a group selected from an alkyl group, an aryl group and a hydrogen atom, and is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group,
Typical examples are an i-butyl group, a t-butyl group, a phenyl group, and a hydrogen atom, but it is an essential requirement that the phenyl group is contained in an amount of 0.1% or more. All R's in the molecule may be the same, some R's may be different groups, and some R's may be vinyl groups or hydroxyl groups. n is 10 to 100
00, and 100-1000 is preferred. n
When it is less than 10, kneading with the ethylene resin is difficult, and when n is more than 10,000, molding is difficult, which is not preferable.

The viscosity of the organopolysiloxane polymer represented by formula (I) used in the present invention at 23 ° C. is 10 CS or more, preferably 10 ³ to 10 ⁶ CS.
The thing of is desirable. When the viscosity is lower than 10 CS, heat kneading is difficult, and the organopolysiloxane polymer may exude from the surface of the molded product. In the present invention, the organopolysiloxane represented by the formula (I) is used in an amount of 10 to 900 parts by weight, preferably 50 to 600 parts by weight, based on 100 parts by weight of the ethylene resin. This is 1
If it is less than 0 parts by weight, it is difficult to obtain flexibility, and 900
This is because if it exceeds the weight part, molding or the like becomes difficult.

In the present invention, the composition comprising the ethylene resin and the organopolysiloxane polymer may further contain an oxidation stabilizer, an ultraviolet stabilizer, an inorganic filler, if necessary.
Pigments, flame retardants, rubbers and the like can be added. In the present invention, kneading is preferably performed at 160 ° C or higher. Kneading must be performed until the gel content reaches 10% or more. If it is less than 10%, unreacted polysiloxane polymer may ooze out, and molding may not be possible due to a slip phenomenon occurring in the extruder. In the present invention, the kneading time can be shortened by adding an organic peroxide to the above composition.

The organic peroxide which can be used in the present invention preferably has a decomposition temperature of 100 to 220 ° C. with a half-life of 10 minutes, that is, a 10 minute half-life temperature (Tp) of 100 to 220 ° C. The following can be given as examples. However, the temperature in parentheses is the decomposition temperature (° C). : Succinic acid peroxide (110), benzoyl peroxide (110), t-butylperoxy-2-ethylhexanoate (113), p-chlorobenzoyl peroxide (115), t-butylperoxyisopropyl carbonate (135), t- Butyl peroxylaurate (140), 2,5-dimethyl-
2,5-di (benzoyloxy) hexane (140),
t-butyl peroxyacetate (140), di-t-
Butyl peroxy phthalate (140), t-butyl peroxy maleic acid (140), cyclohexanone peroxide (145), t-butyl peroxy benzoate (145), dicumyl peroxide (150), 2,
5-Dimethyl-2,5-di (t-butylperoxy) hexane (155), t-butylcumyl peroxide (1
55), t-butyl hydroperoxide (158), di-t-butyl peroxide (160), 2,5-dimethyl 2,5-di (t-butylperoxy) hexane-3.
(170), di-isopropylbenzene hydroperoxide (170), p-menthane hydroperoxide (1
80), 2,5-Dimethylhexane-2,5-dihydroperoxide (213).

The amount of organic peroxide used is 0.001 to 1
Parts by weight are desirable. When it is 0.001 or less, the kneading time becomes long, and when it is 1 part by weight or more, a large amount of gel and lumps are generated, which is not desirable.

The kneading can be carried out using a Banbury mixer, a twin-screw extruder, or any other ordinary kneader. Therefore, the kneaded product in the present invention is a normal inflation molding machine,
With a molding machine such as a T-die molding machine, an injection molding machine, a pipe extruder, and a blow molding machine, it can be molded into films, sheets, pipes, tubes, and other molded products. When formed into a film, its thickness is usually about several microns to several tens of microns. The gel content was calculated by immersing the sample in toluene at 95 ° C. for 24 hours, vacuum-drying it for 24 hours, and calculating the ratio between the existing gel amount and the weight of the original sample.

[0017]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto.

Example 1 A melt index of 20 g / 10 min and an acrylic acid content of 9.5 with respect to 100 parts of a phenyl group-containing polyalkylsiloxane gum stock containing 10 wt.% Of phenyl groups.
100 parts by weight of ethylene-acrylic acid copolymer of wt.% and 1,3-di (t-butylperoxyisopropyl) benzene (Nippon Oil & Fats, trade name "Perbutyl P") 0.03
The parts were kneaded with a Banbury mixer at 160 ° C. for 10 minutes and then pelletized. This pellet is 1 at a pressure of 50 kg / cm ^2.
It was heated and pressed at 50 ° C. for 5 minutes to form a sheet having a thickness of 100 μm. The light transmittance of this sheet at 60 nm was measured with a Jbestos Ubest-50 type spectrophotometer. The results are shown in Table 1 below. It has been shown that the transparency is very good.

Example 2 With respect to 100 parts of phenyl group-containing polyalkylsiloxane gum stock containing 4 wt.% Of phenyl groups, melt index was 20 g / 10 min and acrylic acid content was 9.5 w.
100 parts of an ethylene-acrylic acid copolymer of t.% and 1,3-di (t-butylperoxyisopropyl) benzene (Nippon Yushi-Seal: trade name "Perbutyl P") 0.03
The parts were kneaded with a Banbury mixer at 160 ° C. for 10 minutes and then pelletized. The pellet was formed into a sheet having a thickness of 100 μm. The light transmittance of this sheet is shown in Table 1 below.

Comparative Example 1 With respect to 100 parts of vinyl group-containing polydimethylsiloxane gum stock containing 1 wt.% Of vinyl group, melt index 20 g / 10 min, acrylic acid content of 9.5 wt.%
Of ethylene-acrylic acid copolymer of 100 parts and 1,3
-0.03 parts of di (t-butylperoxyisopropyl) benzene (Nippon Yushi-Seiya: trade name "Perbutyl P") was kneaded with a Banbury mixer at 160 ° C for 10 minutes and then pelletized. The pellet was formed into a sheet having a thickness of 100 μm. The light transmittance of this sheet is shown in Table 1 below.

Example 3 100 parts of a phenyl group-containing polyalkylsiloxane gum stock containing 10 wt.% Of phenyl groups, a melt index of 15 g / 10 min and a vinyl acetate content of 19 w.
100 parts of ethylene-vinyl acetate copolymer of t.% and 1,3-di (t-butylperoxyisopropyl) benzene (Nippon Oil & Fats: trade name "Perbutyl P") 0.03
The parts were kneaded with a Banbury mixer at 160 ° C. for 10 minutes and then pelletized. The pellet was formed into a sheet having a thickness of 100 μm. The light transmittance of this sheet is shown in Table 1 below.

Comparative Example 2 100 parts of an ethylene-vinyl acetate copolymer having a melt index of 15 g / 10 min and a vinyl acetate content of 19 wt.% Was added to 100 parts of a vinyl group-containing polydimethylsiloxane gum stock containing 1 wt.% Of vinyl groups. 1,3-
0.03 parts of di (t-butylperoxyisopropyl) benzene (Nippon Oil & Fats, trade name "Perbutyl P") was kneaded with a Banbury mixer at 160 ° C for 10 minutes and then pelletized. The pellet was formed into a sheet having a thickness of 100 μm.
The light transmittance of this sheet is shown in Table 1 below.

Example 4 With respect to 100 parts of a phenyl group-containing polyalkylsiloxane gum stock containing 10 wt.% Of phenyl groups, a melt index of 20 g / 10 min and a density of 0.924 g / ml.
100 parts of LLDPE and 0.03 part of 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF CORPORATION: trade name “Perbutyl P”) were kneaded with a Banbury mixer at 180 ° C. for 10 minutes and then pelletized. The pellets were heated and pressed at a pressure of 50 kg / cm ² at 150 ° C. for 5 minutes to form a sheet having a thickness of 100 μm. The light transmittance of this sheet is shown in Table 1 below.

Comparative Example 3 LL having a melt index of 20 g / 10 min and a density of 0.924 g / ml with respect to 100 parts of vinyl group-containing polydimethylsiloxane gum stock containing 1 wt.% Of vinyl groups.
160 parts of DPE and 0.03 part of 1,3-di (t-butylperoxyisopropyl) benzene (Nippon Oil & Fats, trade name "Perbutyl P") with a Banbury mixer.
The mixture was kneaded at 10 ° C for 10 minutes and then pelletized. The pellet was formed into a sheet having a thickness of 100 μm. The light transmittance of this sheet is shown in Table 1 below.

[0025]

[Table 1]

Antithrombotic Test Example 5 Inner diameter 3 mm, outer diameter 3.5 mm from the kneaded product produced in Example 1.
A tube of 1 is manufactured, and a 1/10 N aqueous sodium hydroxide solution is circulated inside the tube at 30 ° C. at a flow rate of 50 ml / min for 100 minutes, and then the treatment liquid is allowed to flow out, and then 25 ° C. methanol is added at 50 ml / min. It was circulated for 30 minutes at a flow rate of min, air-dried and then dried under reduced pressure at room temperature. Blood was circulated in this tube at 37 ° C. at a flow rate of 30 ml / min, but after 24 hours, no thrombus was formed and blood flow was observed.

Example 6 From the kneaded product produced in Example 3, an inner diameter of 2.5 mm and an outer diameter of 4.
A 0 mm tube is manufactured, and this tube is attached to a peripheral vein of a beagle dog (2.5 years old, female, 16.5 g),
The patency time was measured and found to be 59 minutes. This patency time indicates the usable time of the artificial blood vessel, and the longer the patency time, the better the artificial blood vessel.

[0028]

INDUSTRIAL APPLICABILITY As described in detail above, according to the present invention, a kneaded product having a gel content of 10% or more obtained by heating and kneading an ethylene resin, a phenyl group-containing organopolysiloxane and an organic peroxide is injection molded, It can be easily molded into a film, sheet, tube, pipe, hollow system, fiber, cloth, etc. by a relatively simple molding method such as inflation molding, extrusion lamination molding, extrusion tube molding, etc. It is possible to manufacture a molded article having improved antithrombogenicity. Therefore, the antithrombotic material produced by this method maintains antithrombogenicity for a long time, and has transparency, flexibility, and
Since it is excellent in biocompatibility, mechanical strength, nontoxicity, workability, low cost, etc., it is extremely useful as various medical materials such as catheters, artificial blood vessels, blood collection tubes, blood bags and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C08L 83/04 LRY 8319-4J

Claims (3)

[Claims] 1. 100 parts by weight of an ethylene-based resin, represented by the following formula (I): (In the formula, R ¹ represents an aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and 0.1% or more of these represents a phenyl group, a and b are the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3), and 10 to 900 parts by weight of a phenyl group-containing organopolysiloxane and an organic peroxide. 0.00
A molded article with improved transparency, which is obtained by molding a kneaded product having a gel content of 10% or more obtained by heating and kneading a resin composition comprising 5 to 1 part by weight. 2. An ethylene- (meth) acrylic acid copolymer 100 parts by weight, the following formula (I): (In the formula, R ¹ represents an aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and 0.1% or more of these represents a phenyl group, a and b are the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3, and 10 to 900 parts by weight of organopolysiloxane and an organic group represented by the formula Transparency obtained by subjecting the surface of a molded product obtained by molding a kneaded product having a gel content of 10% or more obtained by heat kneading a resin composition containing 0.005 to 1 part by weight of a peroxide to an alkali treatment Improved antithrombotic medical supplies. 3. An ethylene-vinyl acetate copolymer 100 parts by weight, the following formula (I): (In the formula, R ¹ represents an aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and 0.1% or more of these represents a phenyl group, a and b are the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3, and 10 to 900 parts by weight of organopolysiloxane and an organic group represented by the formula An antithrombogenic medical article having improved transparency, which is obtained by molding a kneaded product having a gel content of 10% or more obtained by kneading a resin composition containing 0.005 to 1 part by weight of a peroxide.