Medical rubber article and manufacturing method thereof

Abstract

To provide a manufacturing method of a medical rubber article with reduced surface friction coefficient and adhesiveness.SOLUTION: A manufacturing method of a medical rubber article includes: a step of causing a vinyl compound expressed by a general formula (1) to have contact with a cured product of a medical rubber composition including halogenation butyl rubber as a base material polymer (a); and a step of irradiating, with ultraviolet light, the cured product after having contact with the vinyl compound. R-CH=CH2 (1) [In the formula, R denotes an alkyl group having 6 or more carbon atoms].SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to medical rubber articles and a method for manufacturing the same, and more particularly to a technique for reducing the coefficient of friction and adhesiveness on the surface of medical rubber articles.

Background Art

[0002] Halogenated butyl rubber, which has excellent gas barrier properties, is used for medical rubber articles. Since the amount of double bonds that can be vulcanized in halogenated butyl rubber is small, the surface of the rubber article after vulcanization has adhesiveness (high tack value). Therefore, there is a problem that the slidability is poor and the rubber articles stick to each other when stored for a long time. For the purpose of imparting high slidability and reducing the frictional resistance, silicone oil is applied to the surface of the rubber article after vulcanization, or it is laminated with a fluororesin film.

[0003] On the other hand, there is a surface modification method of irradiating a polymer material with ultraviolet rays in order to improve the properties of the polymer material surface.

[0004] For example, in Patent Document 1, a material made of a polymer having a -CH2- bond in the side chain or the main chain is irradiated with ultraviolet rays having a wavelength of 160 to 310 nm in an inert atmosphere, and then the material is irradiated with ultraviolet rays having a wavelength of 200 nm or less in an oxidizing atmosphere, thereby obtaining a material surface modification method for making the wettability of the material surface uniform.

[0005] In Patent Document 2, a vinyl compound represented by the general formula (1) R-CH=CH2 (wherein R represents an alkyl group having 6 or more carbon atoms) is brought into contact with the surface of a polymer material substrate (excluding a fabric substrate), and ultraviolet rays are irradiated, thereby obtaining a surface treatment method for imparting water repellency to the surface of the polymer material substrate.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] To improve slidability, silicone oil is applied to the surface of medical rubber articles or laminated with a fluororesin film. However, when a medical rubber article coated with silicone oil comes into contact with a biopharmaceutical, there is a risk of protein aggregation due to silicone particles. Therefore, medical rubber articles coated with silicone oil cannot be used for medical supplies using biopharmaceuticals. In particular, for the plunger stopper of a prefilled syringe, the need for silicone oil free (SOF) is increasing.

[0008] In addition, laminated medical rubber articles laminated with a fluororesin film such as a polytetrafluoroethylene (PTFE) film have an elastic modulus of the PTFE film 100 times higher than that of rubber, and the sealing property tends to decrease as a plunger stopper of a prefilled syringe.

[0009] As a measure to comply with SOF regulations, a method is required to reduce the coefficient of friction and adhesiveness on the surface of medical rubber articles without using silicone oil.

[0010] The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel medical rubber article with a reduced coefficient of friction and adhesiveness on the surface and a method for manufacturing the same.

Means for Solving the Problems

[0011] The method for manufacturing a medical rubber article of the present invention includes the step of bringing a vinyl compound represented by the following general formula (1) into contact with a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer, It is characterized by including a step of irradiating the cured product after contact with the vinyl compound with ultraviolet rays. R-CH=CH2(1) [In the formula, R represents an alkyl group having 6 or more carbon atoms.]

[0012] The medical rubber article of the present invention is characterized in that one end of an alkyl chain having 8 or more carbon atoms is chemically bonded to the surface of a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer.

[0013] The inventors of the present invention have found that by bringing a specific vinyl compound into contact with a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer (a) and irradiating it with ultraviolet rays, the surface of the cured product is greatly modified to have a low friction coefficient and low adhesiveness (tack value is almost zero), and thus completed the present invention.

Effects of the Invention

[0014] According to the present invention, a medical rubber article with a reduced surface friction coefficient and adhesiveness can be obtained.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

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Figure 7

Figure 8

Mode for Carrying Out the Invention

[0016] The manufacturing method of the medical rubber article of the present invention includes: (a) a step of bringing a vinyl compound represented by the following general formula (1) into contact with a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer; and a step of irradiating the cured product after contact with the vinyl compound with ultraviolet light. R-CH=CH2(1) [In the formula, R represents an alkyl group having 6 or more carbon atoms.]

[0017] The cured product of the medical rubber composition used in the manufacturing method of the present invention is obtained by vulcanizing a medical rubber composition containing halogenated butyl rubber as a base polymer. First, the medical rubber composition used in the present invention will be described.

[0018] <Medical Rubber Composition> [(a) Base Polymer] (a) The base polymer contains halogenated butyl rubber. Halogenated butyl rubber has excellent gas barrier properties and elution characteristics.

[0019] (a) Examples of the halogenated butyl rubber contained in the base polymer include chlorinated butyl rubber, brominated butyl rubber, and brominated products of copolymers of isobutylene and p-methylstyrene. These halogenated butyl rubbers may be used alone or in combination of two or more. As the halogenated butyl rubber, chlorinated butyl rubber or brominated butyl rubber is preferable. The chlorinated butyl rubber or brominated butyl rubber is obtained by adding or substituting chlorine or bromine to the isoprene structural part in butyl rubber, specifically, the double bond and / or the carbon atom adjacent to the double bond. Note that butyl rubber is a copolymer obtained by polymerizing isobutylene and a small amount of isoprene. Note that the halogenated butyl rubber is preferably solid at normal temperature (23°C).

[0020] The halogen content in the halogenated butyl rubber is preferably 0.5% by mass or more, preferably 1% by mass or more, more preferably 1.2% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less.

[0021] (a) When the base polymer contains chlorinated butyl rubber or brominated butyl rubber as the halogenated butyl rubber, a crosslinking reaction occurs at the chlorinated or brominated isoprene moiety in the ultraviolet irradiation step. (a) When the base polymer contains brominated isobutylene-paramethylstyrene copolymer rubber (BIMS) as the halogenated butyl rubber, a crosslinking reaction occurs at the brominated paramethylstyrene site in the ultraviolet irradiation step.

[0022] Specific examples of the chlorinated butyl rubber include, for example, Exxon (registered trademark) Chlorobutyl 1066 manufactured by ExxonMobil [halogen content rate: 1.25 wt%, Mooney viscosity: 38 ML 1+8 (125 °C), specific gravity: 0.92], Exxon Chlorobutyl 5066 [halogen content rate: 1.50 wt%, Mooney viscosity: 40 ML 1+8 (125 °C), specific gravity: 0.92]; at least one such as LANXESS X_BUTYL (registered trademark) CB1240 manufactured by LANXESS.

[0023] Specific examples of the brominated butyl rubber include, for example, Exxon Bromobutyl 2211 manufactured by ExxonMobil [halogen content rate: 2.0 wt%, Mooney viscosity: 32 ML 1+8 (125 °C), specific gravity: 0.93], Exxon Bromobutyl 2222 [halogen content rate: 2.0 wt%, Mooney viscosity: 32 ML 1+8 (125 °C), specific gravity: 0.93], Exxon Bromobutyl 2235 [halogen content rate: 2.1 wt%, Mooney viscosity: 39 ML 1+8(125 °C), specific gravity: 0.93), Exxon Bromobutyl 2244 [halogen content rate: 2.0 wt%, Mooney viscosity: 46 ML 1+8 (125 °C), specific gravity: 0.93), Exxon Bromobutyl 2255 [halogen content rate: 2.1 wt%, Mooney viscosity: 46 ML 1+8 (125 °C), specific gravity: 0.93), Exxon Bromobutyl 6222 [halogen content rate: 2.4 wt%, Mooney viscosity: 32 ML 1+8 (125 °C), specific gravity: 0.93), Exxon Bromobutyl 7211 [halogen content rate: 2.0 wt%, Mooney viscosity: 32 ML 1+8 (125 °C), specific gravity: 0.93), Exxon Bromobutyl 7244 [halogen content rate: 2.1 wt%, Mooney viscosity: 46 ML 1+8 (125 °C), specific gravity: 0.93); at least one such as LANXESS X_BUTYL BBX2 manufactured by LANXESS may be mentioned.

[0024] (a) The base polymer may contain a rubber component other than halogenated butyl rubber. Examples of other rubber components include, for example, butyl rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, natural rubber, chloroprene rubber, nitrile rubbers such as acrylonitrile-butadiene rubber, hydrogenated nitrile rubber, norbornene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, acrylic rubber, ethylene acrylate rubber, fluororubber, chlorosulfonated polyethylene rubber, epichlorohydrin rubber, silicone rubber, urethane rubber, polysulfide rubber, phosphazene rubber, or 1,2-polybutadiene, etc. These may be used alone or in combination of two or more.

[0025] When using other rubber components, (a) the content rate of halogenated butyl rubber in the base polymer is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 98% by mass or more. Also, (a) it is also a preferred embodiment that the base polymer consists only of halogenated butyl rubber.

[0026] The medical rubber composition preferably contains (b) a crosslinking agent. The (b) crosslinking agent is compounded to crosslink the halogenated butyl rubber component contained in the (a) base polymer. As the (b) crosslinking agent, there is no particular limitation as long as it is a crosslinking agent capable of crosslinking halogenated butyl rubber. Examples of the (b) crosslinking agent include sulfur, metal oxides, resin crosslinking agents, organic peroxides, triazine derivatives, etc., and these can be used alone or in combination of two or more.

[0027] Examples of sulfur used as the crosslinking agent include insoluble sulfur, powdered sulfur, fine powdered sulfur, precipitated sulfur, colloidal sulfur, sulfur chloride, etc.

[0028] Examples of metal oxides used as the crosslinking agent include magnesium oxide, calcium oxide, zinc oxide, copper oxide, etc.

[0029] Examples of resin crosslinking agents include alkylphenol formaldehyde resins such as alkylphenol formaldehyde resins, thermoreactive phenol resins, phenol dialcohol resins, bisphenol resins, thermoreactive bromomethylalkylated phenol resins.

[0030] Specific examples of the organic peroxide include dialkyl peroxide, peroxyester, peroxyketal, hydroperoxide, etc. Examples of the dialkyl peroxide include di(2-t-butylperoxyisopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylcumyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, etc. Examples of the peroxyester include t-butyl peroxymaleate, t-butyl peroxy-3,3,5-trimethylcyclohexanoate, t-butyl peroxy laurate, t-butyl peroxyisopropyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxyacetate, t-butyl peroxybenzoate, etc. Examples of the peroxyketal include 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, 1,1-di(t-butylperoxy)-2-methylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, n-butyl-4,4-di(t-butylperoxy)valerate, 2,2-di(4,4-di(t-butylperoxy)cyclohexyl)propane, etc. Examples of the hydroperoxide include p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, etc. These organic peroxides may be used alone or in combination of two or more.

[0031] Examples of the triazine derivative used as the crosslinking agent include the compound represented by the general formula (1).

[0032]

Chemical formula

[0033] [wherein, R is -SH, -OR 1 , -SR 2 , -NHR 3 or -NR 4 R 5 (R 1 , R 2 , R 3 , R 4 and R 5 each represents an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkylaryl group or a cycloalkyl group. R 4 and R 5 may be the same or different.). M 1 and M 2 are H, Na, Li, K, 1 / 2Mg, 1 / 2Ba, 1 / 2Ca, an aliphatic primary amine, a secondary amine or a tertiary amine, a quaternary ammonium salt or a phosphonium salt. M 1 and M 2 may be the same or different.]

[0034] In general formula (1), examples of the alkyl group include alkyl groups having 1 to 12 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, n-hexyl group, 1,1-dimethylpropyl group, octyl group, isooctyl group, 2-ethylhexyl group, decyl group, or dodecyl group. Examples of the alkenyl group include alkenyl groups having 1 to 12 carbon atoms such as vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 1,3-butadienyl group, or 2-pentenyl group. Examples of the aryl group include monocyclic or condensed polycyclic aromatic hydrocarbon groups, and examples thereof include aryl groups having 6 to 14 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group, or acenaphthylenyl group. Examples of the aralkyl group include aralkyl groups having 7 to 19 carbon atoms such as benzyl group, phenethyl group, diphenylmethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 2,2-diphenylethyl group, 3-phenylpropyl group, 4-phenylbutyl group, 5-phenylpentyl group, 2-biphenylylmethyl group, 3-biphenylylmethyl group, or 4-biphenylylmethyl group. Examples of the alkylaryl group include alkylaryl groups having 7 to 19 carbon atoms such as tolyl group, xylyl group, or octylphenyl group. Examples of the cycloalkyl group include cycloalkyl groups having 3 to 9 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, or cyclononyl group.

[0035] Specific examples of the triazine derivative represented by the general formula (1) include, for example, 2,4,6-trimercapto-s-triazine, 2-methylamino-4,6-dimercapto-s-triazine, 2-(n-butylamino)-4,6-dimercapto-s-triazine, 2-octylamino-4,6-dimercapto-s-triazine, 2-propylamino-4,6-dimercapto-s-triazine, 2-diallylamino-4,6-dimercapto-s-triazine, 2-dimethylamino-4,6-dimercapto-s-triazine, 2-dibutylamino-4,6-dimercapto-s-triazine, 2-di(iso-butylamino)-4,6-dimercapto-s-triazine, 2-dipropylamino-4,6-dimercapto-s-triazine, 2-di(2-ethylhexyl)amino-4,6-dimercapto-s-triazine, 2-dioleylamino-4,6-dimercapto-s-triazine, 2-laurylamino-4,6-dimercapto-s-triazine or 2-anilino-4,6-dimercapto-s-triazine, or sodium salts or disodium salts thereof.

[0036] Among these, 2,4,6-trimercapto-s-triazine, 2-dialkylamino-4,6-dimercapto-s-triazine, and 2-anilino-4,6-dimercapto-s-triazine are preferable, and 2-dibutylamino-4,6-dimercapto-s-triazine is particularly preferable from the viewpoint of easy availability.

[0037] Examples of the triazine derivative also include one or more of 6-[bis(2-ethylhexyl)amino]-1,3,5-triazine-2,4-dithiol, 6-diisobutylamino-1,3,5-triazine-2,4-dithiol, 6-dibutylamino-1,3,5-triazine-2,4-dithiol, 6-dibutylamino-1,3,5-triazine-2,4-dithiol·monosodium, 6-anilino-1,3,5-triazine-2,4-dithiol, 1,3,5-triazine-2,4,6-trithiol, etc.

[0038] In the medical rubber composition used in the present invention, as the triazine derivative, one type may be used alone, or two or more types may be used in combination.

[0039] Since the chlorinated butyl rubber and the brominated butyl rubber have different crosslinking mechanisms respectively, it is preferable to select and use the crosslinking component optimal for crosslinking. When the medical rubber composition contains chlorinated butyl rubber as the halogenated butyl rubber, it is preferable to contain a triazine derivative as the (b) crosslinking agent. Further, when the medical rubber composition contains brominated butyl rubber as the halogenated butyl rubber, it is preferable to contain a metal oxide as the (b) crosslinking agent.

[0040] The content of the (b) crosslinking agent in the medical rubber composition is preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more, still more preferably 0.6 parts by mass or more, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less with respect to 100 parts by mass of the (a) base polymer component. If the content of the (b) crosslinking agent is within the above range, a rubber having good rubber physical properties (hardness, tensile strength, Cset) and processability (less scorching) can be obtained.

[0041] When chlorinated butyl rubber is used as the halogenated butyl rubber and a triazine derivative is used as the (b) crosslinking agent, the content of the (b) crosslinking agent in the medical rubber composition is preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more, still more preferably 0.6 parts by mass or more, preferably 4 parts by mass or less, more preferably 3 parts by mass or less, and still more preferably 2 parts by mass or less with respect to 100 parts by mass of the (a) base polymer component. If the content of the (b) crosslinking agent is within the above range, a rubber having good rubber physical properties (hardness, tensile strength, Cset) and processability (less scorching) can be obtained.

[0042] As the halogenated butyl rubber, brominated butyl rubber is used. When a metal oxide is used as the crosslinking agent (b), the content of the crosslinking agent (b) in the medical rubber composition is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, still more preferably 2 parts by mass or more, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less with respect to 100 parts by mass of the base polymer component (a). If the content of the crosslinking agent (b) is within the above range, a rubber with good rubber physical properties (hardness, tensile strength, Cset) and processability (less scorching) can be obtained.

[0043] The medical rubber composition preferably does not contain a vulcanization accelerator. This is because the vulcanization accelerator may remain in the final rubber product and elute into the chemical solution in a syringe or the like. Examples of the vulcanization accelerator include guanidine-based accelerators (e.g., diphenylguanidine), thiuram-based accelerators (e.g., tetramethylthiuram disulfide, tetramethylthiuram monosulfide), dithiocarbamate-based accelerators (e.g., zinc dimethyldithiocarbamate), thiazole-based accelerators (e.g., 2-mercaptobenzothiazole, dibenzothiazyl disulfide), and sulfenamide-based accelerators (N-cyclohexyl-2-benzothiazole sulfenamide, N-t-butyl-2-benzothiazole sulfenamide).

[0044] The medical rubber composition may further contain an acid acceptor. The acid acceptor functions to absorb chlorine-based gases or bromine-based gases generated during the crosslinking of the halogenated butyl rubber and prevent the occurrence of crosslinking inhibition and the like caused by these gases. In addition, the acid acceptor functions as a scorch inhibitor during the crosslinking of the halogenated butyl rubber and also functions to prevent an increase in the compression set of the medical rubber parts.

[0045] Examples of the acid acceptor include hydrotalcite, metal oxides, and metal hydroxides.

[0046] Examples of hydrotalcite include Mg4.5 Al2(OH) 13 CO3·3.5H2O, Mg 4.5 Al2(OH) 13 CO3, Mg4Al2(OH) 12 CO3·3.5H2O, Mg6Al2(OH) 16 CO3·4H2O, Mg5Al2(OH) 14 CO3·4H2O, Mg3Al2(OH) 10 Examples of the Mg - Al - type hydrotalcite include Mg - Al - type hydrotalcite such as Al2(OH)CO3·3.5H2O, MgO, Mg4Al2(OH)CO3, Mg6Al2(OH)CO3·3.5H2O, Mg5Al2(OH)CO3·4H2O, Mg3Al2(OH)CO3·4H2O, Mg3Al2(OH)CO3·1.7H2O, etc. Examples of the metal oxide include magnesium oxide, calcium oxide, zinc oxide, etc. Examples of the metal hydroxide include calcium hydroxide, etc. These acid acceptors may be used alone or in combination of two or more. Note that the metal oxide used as the cross - linking agent described above can also function as an acid acceptor.

[0047] The content of the acid acceptor is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less with respect to 100 parts by mass of the base polymer component. If the content of the acid acceptor is within the above range, generation of rust on the mold, etc. can be suppressed, and the problem that the raw material itself becomes white - point foreign matter can be reduced.

[0048] The medical rubber composition may further contain a filler. Examples of the filler include inorganic fillers such as clay and talc. Among these, the filler is preferably an inorganic filler, and more preferably clay or talc. The filler functions to adjust the rubber hardness of the medical rubber parts and also functions to reduce the production cost of the medical rubber parts as a bulking agent.

[0049] Examples of the clay include fired clay and kaolin clay. Specific examples of the clay include, for example, SILLITIN (registered trademark) Z manufactured by HOFFMANN MINERAL, SATINTONE (registered trademark) W manufactured by ENGELHARD, NN kaolin clay manufactured by Tsuchiya Kaolin Industry Co., Ltd., PoleStar200R manufactured by Imerys Specialties Japan Co., Ltd., and the like.

[0050] Specific examples of the talc include, for example, HITRON A manufactured by Takehara Chemical Industry Co., Ltd., MICRO ACE (registered trademark) K-1 manufactured by Nippon Talc Co., Ltd., Mistron (registered trademark) Vapor manufactured by Imerys Specialties Japan Co., Ltd., and the like.

[0051] The content of the filler in the medical rubber composition is preferably set as appropriate according to the rubber hardness and the like of the target medical rubber article. The content of the filler in the medical rubber composition is, for example, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 20 parts by mass or more, preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and still more preferably 100 parts by mass or less with respect to 100 parts by mass of the base polymer component.

[0052] The medical rubber composition may further be blended with a coloring agent such as titanium oxide and carbon black, a lubricant such as stearic acid, a processing aid, polyethylene glycol as a crosslinking activator, a process oil, and the like in appropriate proportions.

[0053] The medical rubber composition is obtained by kneading (a) a base polymer, (b) a crosslinking agent, and other compounding materials added as necessary. The kneading can be performed using, for example, an open roll, a closed kneader, or the like. The kneaded product is preferably formed into a ribbon shape, a sheet shape, a pellet shape, or the like, and more preferably formed into a sheet shape.

[0054] The manufacturing method of the medical rubber article of the present invention may include a step of curing the medical rubber composition. The cured product of the medical rubber composition used in the present invention is obtained by vulcanizing (crosslinking) the medical rubber composition. By press-molding a ribbon-shaped, sheet-shaped, or pellet-shaped kneaded product, a cured product of the medical rubber composition having a desired shape can be obtained. The crosslinking reaction of the medical rubber composition proceeds during pressing. The molding temperature is preferably, for example, 130 °C or higher, more preferably 140 °C or higher, preferably 200 °C or lower, and more preferably 190 °C or lower. The molding time is preferably 2 minutes or longer, more preferably 3 minutes or longer, preferably 60 minutes or shorter, and more preferably 30 minutes or shorter. The molding pressure is preferably 0.1 MPa or higher, more preferably 0.2 MPa or higher, preferably 10 MPa or lower, and more preferably 8 MPa or lower.

[0055] At least a part of the surface of the cured product of the medical rubber composition to which the present invention is applied may be coated with an inert resin layer. For example, by press-molding in a state where an inert resin film is stacked on a sheet made of a medical rubber composition, at least a part of the surface of the cured product of the medical rubber composition is coated with an inert resin layer.

[0056] The inert resin layer only needs to cover at least a part of the surface of the medical rubber article, and it is preferably laminated appropriately according to the form of the medical rubber article. In particular, it is preferable to provide an inert resin layer on the surface of the medical rubber article that comes into contact with the drug. In this aspect, the inert resin layer exhibits good chemical resistance and can improve the slidability of the surface where the inert resin layer is not provided.

[0057] The resin constituting the inert resin layer is not particularly limited, but from the viewpoint of obtaining good chemical resistance, at least one fluororesin selected from the group consisting of tetrafluoroethylene·ethylene copolymer (ETFE), polytetrafluoroethylene (PTFE), and polychlorotetrafluoroethylene (PCTFE), or a non-fluororesin can be mentioned.

[0058] Tetrafluoroethylene-ethylene copolymer (ETFE) is a copolymer of ethylene and tetrafluoroethylene in a molar ratio of 30 / 70 to 70 / 30. There is also modified ETFE obtained by copolymerizing other components for modification purposes. Examples of other components include fluorine-containing olefins and hydrocarbon-based olefins. Specifically, α-olefins such as propylene and butene, fluorine-containing olefins such as hexafluoropropylene, vinylidene fluoride, perfluorobutylethylene, and trifluorochloroethylene, vinyl ethers such as ethylene vinyl ether, perfluoromethyl vinyl ether, and perfluoropropyl vinyl ether, and fluorine-containing acrylates, etc. are copolymerized in an amount of about 2 to 10 mol% to modify ETFE.

[0059] As the modified ETFE, ETFE having a functional group that imparts adhesiveness can be preferably used. Examples of the functional group include carboxyl group, carboxyl anhydride group, epoxy group, hydroxyl group, isocyanate group, ester group, amide group, aldehyde group, amino group, cyano group, carbon-carbon double bond, sulfonic acid group, ether group, etc. Examples of commercially available modified ETFE include Fluon AH-2000 manufactured by Asahi Glass Co., Ltd.

[0060] Examples of non-fluorine resins include olefin resins. Examples of the olefin resins include polyethylene resins such as polyethylene, ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, and chlorinated polyethylene; polypropylene resins such as polypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, and chlorinated polypropylene; polybutene, polyisobutylene, polymethylpentene, and copolymers of cyclic olefins, etc. Polyethylene (especially ultra-high molecular weight polyethylene (UHMWPE)) is preferred. Also, the olefin resin may contain fluorine.

[0061] The thickness of the inert resin film to be used may be appropriately adjusted according to the shape and size of the medical rubber article, but is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more, preferably 150 μm or less, more preferably 130 μm or less, and still more preferably 110 μm or less. If the thickness of the inert resin film is within the above range, film breakage during product molding and defects such as wrinkles and floating on the film surface of the product after molding will not occur, and both moldability and product characteristics can be achieved.

[0062] The arithmetic mean roughness Ra of the inert resin film can be from 0.01 to 0.03 μm for casting films and extrusion films, or 0.10 μm for skiving films. By making the surface roughness of the mold 0.03 μm or less, a medical rubber article excellent in liquid tightness and air tightness can be obtained. The lower limit of Ra of the inert film itself is not particularly limited.

[0063] It is preferable to perform a treatment for enhancing the adhesiveness with rubber or the like on the inert resin film. Examples of the treatment for enhancing the adhesiveness include chemical treatment methods, treatments for roughening the surface of the film, and combinations thereof. Specific examples include sodium treatment, glow discharge treatment, plasma treatment (discharge treatment) under atmospheric pressure or in a vacuum, excimer laser treatment (discharge treatment), and ion beam treatment.

[0064] <Method for manufacturing medical rubber article> Hereinafter, the method for manufacturing a medical rubber article of the present invention will be described. The method for manufacturing a medical rubber article of the present invention includes a step of bringing a vinyl compound represented by the following general formula (1) into contact with a cured product of the medical rubber composition (hereinafter sometimes referred to as the "vinyl compound contact step"), and a step of irradiating ultraviolet rays to the cured product after contact with the vinyl compound (hereinafter sometimes referred to as the "ultraviolet irradiation step"). R-CH=CH2(1) [In the formula, R represents an alkyl group having 6 or more carbon atoms.]

[0065] [Vinyl Compound Contact Step] The vinyl compound contact step is a step of bringing the vinyl compound represented by the general formula (1) into contact with the cured product of the medical rubber composition. The vinyl compound represented by the general formula (1) attached to the surface of the cured product in the vinyl compound contact step has its double bond of the vinyl compound cleaved to generate an alkyl radical in the ultraviolet irradiation step described later, and the generated alkyl radical binds to the surface of the cured product. That is, one end (the end on the double bond side) of the alkyl chain (the part represented by R) of the vinyl compound is chemically bonded to the surface of the cured product. As a result, the surface free energy of the cured product is reduced, and a low coefficient of friction and low adhesiveness on the surface of the cured product can be realized.

[0066] The vinyl compound used in the vinyl compound contact step is an α-olefin in which R is an alkyl group having 6 or more carbon atoms. If the alkyl group represented by R has 6 or more carbon atoms, the effect of reducing the coefficient of friction and adhesiveness on the surface of the cured product is likely to be exhibited. From the viewpoint of further enhancing the effect of reducing the coefficient of friction and adhesiveness on the surface of the cured product, the number of carbon atoms of the alkyl group represented by R is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more. Also, the number of carbon atoms of the alkyl group represented by R is not particularly limited, but is preferably 20 or less, more preferably 19 or less, and even more preferably 18 or less. This is because when the number of carbon atoms of the alkyl group represented by R is 20 or more, high slidability is lost.

[0067] The alkyl group represented by R may be linear, branched, or cyclic, but is preferably linear from the viewpoint of further enhancing the effect of reducing the coefficient of friction and adhesiveness on the surface of the cured product.

[0068] Specific examples of the vinyl compound include 1-octadecene, 1-nonadecene, 1-eicosene, 1-henicosene, 1-docosene, and the like. The alkyl group part of the vinyl compound may be linear, branched, or cyclic, but is preferably linear. These vinyl compounds may be used alone or in combination of two or more.

[0069] The method of bringing the vinyl compound into contact with the cured product of the medical rubber composition is not particularly limited. For example, a method of applying a liquid vinyl compound or a vinyl compound-containing liquid to the surface of the cured product of the medical rubber composition, a method of immersing the cured product of the medical rubber composition in a liquid vinyl compound or a vinyl compound-containing liquid, a method of placing the cured product of the medical rubber composition in a container into which a gaseous vinyl compound is introduced, and the like can be mentioned. Further, it is also preferable to mask a part of the surface of the cured product of the medical rubber composition and bring the vinyl compound into contact with only a desired portion. Among these, from the viewpoint of uniform coating, a method of applying a vinyl compound-containing liquid to the surface of the cured product of the medical rubber composition is preferable. The coating method is not particularly limited, and known methods such as spraying and coating with a brush can be mentioned.

[0070] As the vinyl compound-containing liquid, a solution in which a vinyl compound is dissolved is preferable. The solvent for dissolving the vinyl compound is not particularly limited, and examples thereof include hexane, butyl acetate, benzene, toluene, and the like.

[0071] In the vinyl compound-containing liquid, the concentration of the vinyl compound is not particularly limited, but it is preferably 2.0 g / L or more, more preferably 5.0 g / L or more, still more preferably 8.0 g / L or more, preferably 25.0 g / L or less, more preferably 20.0 g / L or less, and still more preferably 15.0 g / L or less. If the concentration of the vinyl compound is within the above range, the effect of reducing the coefficient of friction and adhesiveness by the vinyl compound is likely to be exhibited.

[0072] In the vinyl compound contact step, it is preferable to remove the solvent of the vinyl compound-containing liquid adhering to the surface of the cured product. The method for removing the solvent of the vinyl compound-containing liquid is not particularly limited, and for example, it can be carried out by natural drying or vacuum drying.

[0073] The amount of the vinyl compound adhered to the cured product of the medical rubber composition is not particularly limited, but 0.19 mg / cm 2It is preferably the above, 0.47 mg / cm 2 More preferably, it is the above, 0.75 mg / cm 2 Even more preferably, it is the above, 2.34 mg / cm 2 It is preferably below, 1.90 mg / cm 2 More preferably, it is below, 1.41 mg / cm 2 Even more preferably, it is below. If the amount of the vinyl compound added is within the above range, the effect of reducing the friction coefficient and adhesiveness by the vinyl compound is likely to be exhibited.

[0074] <UV irradiation step> The method for producing the medical rubber article of the present invention includes a step of irradiating ultraviolet rays to the cured product after contact with the vinyl compound (UV irradiation step). The cured product of the medical rubber composition to which ultraviolet rays are irradiated may be formed into the shape of the final medical rubber article, or may be a preform before being formed into the shape of the final medical rubber article.

[0075] The method of irradiating ultraviolet rays to the cured product of the medical rubber composition is not particularly limited. For example, it may be irradiated to at least a part of the surface of the cured product of the medical rubber composition using a light source that emits ultraviolet rays. For example, modes of irradiating ultraviolet rays only to the part of the surface of the cured product of the medical rubber composition where the vinyl compound is applied, or irradiating ultraviolet rays to the entire cured product including the part where the vinyl compound is applied can be mentioned. Also, it is preferable to mask a part of the surface of the cured product of the medical rubber composition and irradiate ultraviolet rays only to the desired part.

[0076] The wavelength of the ultraviolet light is preferably 160 nm or more, more preferably 165 nm or more, and even more preferably 170 nm or more. This is because surface modification can be achieved when the wavelength of the ultraviolet light is 160 nm or more. Also, although the upper limit of the wavelength of the ultraviolet light is not particularly limited, it is preferably 380 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. When the wavelength of the ultraviolet light is 380 nm or less, the energy of the ultraviolet light becomes higher, the crosslinking efficiency of the halogenated butyl rubber becomes higher, and it becomes less likely to deform. Also, the low molecular components that contribute to the surface tackiness of the cured product of the medical rubber composition are decomposed and evaporated by the high-energy ultraviolet light, and low tackiness can be achieved. Furthermore, since the surface of the cured product becomes rough due to the evaporation of the low molecular components, the coefficient of friction can be further reduced. Among these, vacuum ultraviolet light with a wavelength of 200 nm or less is particularly preferable from the viewpoint of obtaining the effects of the present invention more favorably.

[0077] The light source that emits the ultraviolet light is not particularly limited as long as it can emit ultraviolet light in the above wavelength range. For example, a low-pressure mercury lamp, a high-pressure mercury lamp, an excimer lamp, etc. are used. In particular, an excimer lamp is preferable because it has strong energy and the surface can be modified in a relatively short time. The excimer lamp emits ultraviolet light with different wavelengths depending on the type of discharge gas used. For example, when xenon (Xe2) is used, it emits ultraviolet light with a central wavelength of 172 nm, when xenon chloride (XeCl) is used, it emits ultraviolet light with a central wavelength of 308 nm, when xenon bromide (XeBr) is used, it emits ultraviolet light with a central wavelength of 283 nm, when xenon iodide (XeI) is used, it emits ultraviolet light with a central wavelength of 253 nm, when argon fluoride (ArF) is used, it emits ultraviolet light with a central wavelength of 193 nm, when argon bromide (ArBr) is used, it emits ultraviolet light with a central wavelength of 165 nm, when krypton chloride (KrCl) is used, it emits ultraviolet light with a central wavelength of 222 nm, and when krypton bromide (KrBr) is used, it emits ultraviolet light with a central wavelength of 207 nm (also called "excimer UV light"). In the present invention, an excimer lamp that emits vacuum ultraviolet light with a central wavelength of 200 nm or less is preferable, and an excimer lamp using xenon (central wavelength: 172 nm) is particularly preferable.

[0078] In the ultraviolet irradiation step, the integrated illuminance of ultraviolet rays on the cured product of the medical rubber composition is preferably 1000 mJ / cm 2 or more, more preferably 3000 mJ / cm 2 or more, and even more preferably 5000 mJ / cm 2 or more. If the integrated illuminance of ultraviolet rays on the cured product of the medical rubber composition is 1000 mJ / cm 2 or more, the crosslinking of the halogenated butyl rubber is sufficiently carried out, and the low-molecular components contributing to the surface tackiness of the cured product of the medical rubber composition are more easily decomposed. Further, the upper limit of the integrated illuminance of ultraviolet rays on the cured product of the medical rubber composition is not particularly limited, but is preferably 50000 mJ / cm 2 or less, more preferably 45000 mJ / cm 2 or less, and even more preferably 40000 mJ / cm 2 or less. If the integrated illuminance of ultraviolet rays on the cured product of the medical rubber composition is 50000 mJ / cm2 or less, it is because the balance between the life of the irradiation equipment and the efficiency of surface modification can be achieved. The integrated illuminance of ultraviolet rays on the cured product of the medical rubber composition is the total illuminance (arrival illuminance) of ultraviolet rays reaching the surface of the cured product of the medical rubber composition, and can be calculated by multiplying the intensity of ultraviolet rays (arrival intensity) reaching the surface of the cured product of the medical rubber composition by the irradiation time of ultraviolet rays.

[0079] The arrival intensity and irradiation time of the ultraviolet rays may be appropriately adjusted so as to obtain the integrated illuminance within the above-mentioned range. Usually, the arrival intensity of the ultraviolet rays is 10 mW / cm 2 / sec to 100 mW / cm 2 / sec, and the irradiation time is preferably 10 seconds to 5000 seconds. By setting the arrival intensity and irradiation time of the ultraviolet rays within these ranges, it is easy to obtain the integrated illuminance within the above-mentioned range.

[0080] The distance between the surface of the cured product of the medical rubber composition and the light source (lamp) that emits ultraviolet rays is not particularly limited, but is preferably 1 mm to 20 mm from the viewpoint of enhancing the uniformity of ultraviolet irradiation.

[0081] In the present invention, by irradiating the cured product of the medical rubber composition after contact with the vinyl compound with ultraviolet rays, the surface of the cured product can be greatly modified to have a low coefficient of friction and low adhesiveness.

[0082] In the production method of the present invention, when at least a part of the surface of the cured product of the medical rubber composition is coated with an inert resin layer, it is preferable to bring the vinyl compound into contact with at least a part of the surface of the cured product that is not coated with the inert resin layer and is exposed, and then irradiate with ultraviolet rays. As long as ultraviolet rays are irradiated on the portion where the vinyl compound adheres to the surface of the cured product, ultraviolet rays may be irradiated only on a part of the exposed surface of the cured product, or the entire exposed surface of the cured product may be irradiated with ultraviolet rays.

[0083] In the production method of the present invention, when at least a part of the surface of the cured product of the medical rubber composition is coated with an inert resin layer, it is preferable to bring the vinyl compound into contact with only the surface of the cured product that is not coated with the inert resin layer and is exposed. When bringing the vinyl compound into contact with the inert resin layer, it is preferable to remove the vinyl compound adhering to the inert resin layer without irradiating the inert resin layer with ultraviolet rays.

[0084] The production method of the medical rubber article of the present invention may include a step of processing the cured product of the medical rubber composition into a predetermined shape, a step of washing, a step of sterilizing, and a step of drying. For example, from the cured product of the medical rubber composition after ultraviolet irradiation, unnecessary portions are cut off and removed to obtain a predetermined shape, and then it is further washed, sterilized, dried, and packaged to produce a medical rubber article. Note that cutting off and removing unnecessary portions to obtain a predetermined shape may be performed before irradiating the cured product of the medical rubber composition with ultraviolet rays.

[0085] The medical rubber article obtained by the production method of the present invention can achieve a low coefficient of friction and low adhesiveness without using silicone oil. Therefore, the medical rubber article of the present invention can be suitably used as a medical rubber article that requires a low coefficient of friction and low adhesiveness while being compliant with SOF regulations.

[0086] In terms of SOF compliance, it is preferable that the silicone oil is not applied to the medical rubber article obtained by the production method of the present invention. Examples of the silicone oil include dimethylpolysiloxane, methylphenylpolysiloxane, and modified products thereof.

[0087] Examples of the medical rubber article obtained by the production method of the present invention include rubber stoppers and seal members for containers for various drugs such as liquid agents, powder preparations, and freeze-dried preparations, rubber stoppers for vacuum blood collection tubes, plunger stoppers (gaskets) for prefilled syringes, or sliding or seal parts such as nozzle caps. Among these, medical rubber parts (for example, rubber stoppers and plunger stoppers) that require a low friction coefficient and low adhesiveness are preferable, and plunger stoppers that require excellent slidability are particularly preferable.

[0088] Among these, rubber stoppers and seal members including those for vials and infusion preparation containers are preferably represented by the durometer type A hardness (Shore A hardness) measured according to the measurement method described in Japanese Industrial Standard JIS K6253-3:2012 "Vulcanized Rubber and Thermoplastic Rubber - Method for Measuring Hardness - Part 3: Durometer Hardness" and are preferably 35 or more and preferably 60 or less.

[0089] Further, for the sliding or seal parts such as gaskets for prefilled syringes and nozzle caps, the Shore A hardness is preferably 40 or more and preferably 70 or less.

[0090] The rubber hardness of the medical rubber article can be adjusted by changing the blending ratio of each raw material.

[0091] <Medical Rubber Parts> The present invention includes a medical rubber article characterized in that one end of an alkyl chain having 8 or more carbon atoms is chemically bonded to the surface of a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer.

[0092] One end of an alkyl chain having 8 or more carbon atoms is chemically bonded to the surface, reducing the surface free energy of the medical rubber article, thereby achieving a low coefficient of friction and low adhesiveness. From the viewpoint of further enhancing the effect of reducing the coefficient of friction and adhesiveness of the surface of the medical rubber article, the number of carbon atoms of the alkyl chain is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more. Also, although the number of carbon atoms of the alkyl chain is not particularly limited, it is preferably 20 or less, more preferably 19 or less, and even more preferably 18 or less. This is because when the number of carbon atoms of the alkyl chain is 20 or less, it becomes possible to achieve high slidability.

[0093] The alkyl chain may be linear, branched, or cyclic, but is preferably linear from the viewpoint of further enhancing the effect of reducing the coefficient of friction and adhesiveness of the surface of the medical rubber part.

[0094] Specific examples of the alkyl chain include an octyl chain, a nonyl chain, a decyl chain, an undecyl chain, a dodecyl chain, a tridecyl chain, a tetradecyl chain, a pentadecyl chain, a hexadecyl chain, a heptadecyl chain, an octadecyl chain, a nonadecyl chain, an eicosyl chain, and the like. The alkyl chain may be linear, branched, or cyclic, but is preferably linear. The alkyl chain chemically bonded to the surface of the cured product of the medical rubber composition may be only one type or two or more types.

[0095] Regarding each component of the medical rubber composition constituting the medical rubber article of the present invention and the molding conditions of the cured product, it is as described above.

[0096] Hereinafter, specific examples of the medical rubber article to which the present invention is applied will be described. <Plunger stopper> Figure 1 is a diagram showing in an exploded state a medical syringe in which the medical rubber part of the present invention is used, that is, a syringe called a prefilled syringe 30. In Figure 1, the syringe barrel 31 and the plunger stopper 33 are each shown with half of their cross-sections. The prefilled syringe 30 includes a cylindrical syringe barrel 31, a plunger 32 combined with the syringe barrel 31 and capable of reciprocating within the syringe barrel 31, and a plunger stopper 33 attached to the tip of the plunger 32.

[0097] The plunger 32 is made of, for example, a resin plate piece having a cross-section in a cross shape, and a head portion 38 to which the plunger stopper 33 is attached is provided at its tip. The head portion 38 is made of resin integrally formed with the plunger 32 and is machined into a male screw shape. The plunger stopper 33 has a substantially cylindrical shape with a short axis, and its tip surface has, for example, a blunt angled mountain shape with the axial center portion protruding. And a female screw-shaped fitting recess 35 engraved axially from the rear end surface is formed. By screwing the head portion 38 of the plunger 32 into the fitting recess 35 of the plunger stopper 33, the plunger stopper 33 is attached to the tip of the plunger 32.

[0098] Figure 2 is a semi-sectional front view of an example of a plunger stopper. The plunger stopper 40 includes a main body 41 made of a cured product of a medical rubber composition and an inert resin layer 42 covering a part of the surface of this main body. The plunger stopper 40 has a liquid contact surface portion 47 facing the chemical solution and a sliding surface portion 46 contacting the syringe barrel.

[0099] In the embodiment shown in Figure 2, when the plunger stopper 40 is inserted into the syringe barrel, only the mountain-shaped liquid contact surface portion 47 in contact with the chemical solution is covered with the inert resin layer 42. As the inert resin layer 42, for example, a polytetrafluoroethylene film is preferable.

[0100] The sliding surface portion (outer circumferential surface) 46 where the plunger stopper 40 contacts the syringe barrel is not provided with an inert resin layer, and the cured product of the medical rubber composition is exposed. A vinyl compound is applied to the surface of the cured product that is this sliding surface portion, and ultraviolet irradiation is performed. The sliding surface portion (outer circumferential surface) 46 has high slidability.

[0101] The plunger stopper 40 has a short cylindrical shape and has a plurality of annular ribs 43, 44, 45 on the outer circumferential surface 46 of the cylindrical shape. The annular ribs are in sliding contact with the inner circumferential surface of the syringe barrel. The plurality of annular ribs are arranged in the axial direction from the tip end surface (liquid contact surface portion) 47 to the rear end surface 48 of the plunger stopper. The number of annular ribs is not particularly limited as long as it is 1 or more, but it is preferably 2 or more, more preferably 3 or more, preferably 6 or less, more preferably 5 or less, and even more preferably 4 or less.

[0102] The plunger stopper 40 in FIG. 2 has a first annular rib 43, a second annular rib 44, and a third annular rib 45 from the tip end side. The first annular rib 43 at the tip preferably has a radial compression rate of 1% or more, more preferably 2% or more, even more preferably 3% or more, preferably 10% or less, more preferably 9% or less, and even more preferably 8% or less. The compression rate is calculated by the following formula from the outer diameter D1 of the annular rib in the uncompressed state and the inner diameter R of the syringe barrel. Compression rate (%) = 100×(D1 - R) / D1

[0103] The linear length H1 (the axial length) of the sliding contact portion of the annular rib 43 at the tip is preferably 1% or more, more preferably 3% or more, even more preferably 6% or more, preferably 25% or less, more preferably 20% or less, and even more preferably 15% or less with respect to the linear length of the outer circumferential surface of the cylindrical shape (the axial length of the outer circumferential surface) Ho.

[0104] The linear length H2 (the axial length) of the sliding contact portion of the second annular rib 44 and the linear length H3 (the axial length) of the sliding contact portion of the third annular rib 45 are preferably 1% or more, more preferably 2% or more, further preferably 3% or more, preferably 15% or less, more preferably 14% or less, and further preferably 13% or less with respect to the linear length Ho (the axial length of the outer circumferential surface) of the cylindrical outer circumferential surface.

[0105] Incidentally, the plunger stopper may be referred to as a stopper or a gasket.

[0106] <Rubber stopper> FIG. 3 is an explanatory view for explaining an example of a medical plug body to which the present invention is applied. More specifically, it is a rubber stopper of a vial. FIG. 3(a) is a plan view, and FIG. 3(b) is a cross-sectional view taken along line A-A in FIG. 3(a).

[0107] The medical plug body 50 has a top plate 53 and a cylindrical leg portion 55 extending downward from the lower surface of the top plate 53. The top plate 53 and the leg portion 55 are made of a cured product of a rubber composition. The leg portion 55 fits into the mouth portion of the medical container when the medical container is plugged with the medical plug body of the present invention. In FIG. 3(b), the opposing inner surfaces of the cylindrical leg portion 55 are tapered so that the distance between the inner surfaces of the leg portion gradually decreases from the bottom upward (toward the top surface side).

[0108] The top plate 53 is circular in plan view. The top plate 53 has a puncture portion 53a that allows a syringe needle to puncture therethrough, and a flange portion 53b that contacts the upper edge surface of the mouth portion of the medical container when the medical container is plugged.

[0109] On the top surface side of the flange portion 53b, a protrusion 57 is provided to prevent adhesion to other rubber stoppers.

[0110] The puncture portion 53a is an area for inserting an injection needle to aspirate the chemical solution inside the container on the top plate 53. The puncture portion 53a is circular in plan view and is located at the center of the top plate 53. Further, the puncture portion 53a is formed in a concave shape from the top surface.

[0111] In the aspect of FIG. 3, the entire lower surface of the top plate 53 and the surface of the leg portion 55 are covered by the inert resin layer 59. Note that the inert resin layer 59 may cover at least a part of the lower surface of the top plate 53 and the surface of the leg portion 55. As the inert resin layer 59, a polytetrafluoroethylene film is preferable.

[0112] The upper surface of the top plate 53 is not provided with an inert resin layer, and the cured product of the medical rubber composition is exposed. A vinyl compound is applied to the surface of the cured product, which is the upper surface of this top surface, and ultraviolet irradiation is performed. Since the upper surface of the top plate 53 has a reduced coefficient of friction and adhesiveness, the problem of rubber stoppers sticking to each other is improved.

[0113] FIG. 4 is an explanatory diagram showing another aspect of the medical rubber stopper 50 to which the present invention is applied. FIG. 4(a) is a plan view, and FIG. 4(b) is a cross-sectional view taken along line B-B in FIG. 4(a). In the medical rubber stopper 50 of FIG. 4, the description of the parts having the same configuration as in FIG. 3 is omitted.

[0114] The medical rubber stopper 50 of this aspect has bifurcated leg portions 55 extending from the lower surface of the top plate 53. In FIG. 4(b), the opposing inner surfaces of the bifurcated leg portions 55 are formed in a tapered shape such that the distance between the inner surfaces of the legs gradually decreases from below upward (toward the top surface side). In the aspect of FIG. 4, the top plate 53 and the leg portions 55 are composed of a cured product of a rubber composition, and the entire lower surface of the top plate 53 and the surface of the leg portions 55 are covered by the inert resin layer 59. Note that the inert resin layer 59 may cover at least a part of the lower surface of the top plate 53 and the surface of the leg portions 55.

[0115] The upper surface of the top plate 53 is not provided with an inert resin layer, and the cured product of the medical rubber composition is exposed. A vinyl compound is applied to the surface of the cured product, which is the upper surface of this top surface, and ultraviolet irradiation is performed. Since the upper surface of the top plate 53 has a reduced coefficient of friction and adhesiveness, the problem of rubber stoppers sticking to each other is improved.

[0116] A nylon film layer may be provided on the top surface portion of the top plate 53 of the medical rubber stopper 50 in FIGS. 3 and 4. By providing a nylon film layer on the top surface portion of the medical rubber stopper 50, the mechanical transportability during pharmaceutical production can be ensured. In addition, by providing a nylon film layer on the top surface portion of the medical rubber stopper 50, the surface smoothness of the top surface portion can be increased, and the generation of needle puncture fragments can be prevented during the puncture of the injection needle.

[0117] <Rubber stopper for vacuum blood collection tube> FIG. 5 is an explanatory view showing an example of a vacuum blood collection tube. The vacuum blood collection tube 90 includes a bottomed tube 91 and a rubber stopper 93 that seals the opening of the bottomed tube 91. It is designed to be able to automatically collect blood by reducing the pressure inside the blood collection tube.

[0118] FIG. 6 is an explanatory view for explaining an example of a medical stopper to which the present invention is applied. It is an explanatory view showing an example of a rubber stopper for a vacuum blood collection tube. FIG. 6(a) is a perspective view, and FIG. 6(b) is a cross-sectional view. The rubber stopper of the vacuum blood collection tube has a top plate 94 and a cylindrical leg portion 95 that extends downward from the lower surface of the top plate 94. The top plate 94 and the leg portion 95 are made of an elastic body. The leg portion 95 fits into the mouth portion of the vacuum blood collection tube when the vacuum blood collection tube is stoppered with the rubber stopper. A puncture portion 96, which is an area for inserting an injection needle, is provided at the center of the top plate 94. The puncture portion 96 is formed in a concave shape from the top surface. The entire lower surface of the top plate 94 and the surface of the leg portion 95 are covered with an inert resin layer 97. Note that the inert resin layer 97 may cover at least a part of the lower surface of the top plate 94 and the surface of the leg portion 95.

[0119] The upper surface of the top plate 94 is not provided with an inert resin layer, and the cured product of the medical rubber composition is exposed. A vinyl compound is applied to the surface of the cured product, which is the upper surface of this top plate, and ultraviolet irradiation is performed. Since the friction coefficient and adhesiveness of the upper surface of the top plate 94 are reduced, the problem of rubber stoppers sticking to each other is improved.

[0120] <Nozzle cap> FIG. 7(a) is a cross-sectional view showing an example of a nozzle cap of a medical syringe and the nozzle of a syringe barrel that covers it. FIG. 7(b) is a cross-sectional view showing a state where the nozzle cap is put on the nozzle. The nozzle cap 81 is integrally formed from a medical rubber composition. The nozzle cap 81 includes a cylindrical portion 86 whose inner diameter D8 is slightly smaller than the outer diameter D9 of the nozzle 83, and a needle puncture portion 87 that is integrally connected to one end side (the upper end side in the figure) of the cylindrical portion 86. The needle puncture portion 87 is formed in a columnar shape having an outer surface continuous with the cylindrical portion 86. An opening 88 is provided at the other end side (the lower end side in the figure) of the cylindrical portion 86 for inserting the nozzle 83 into the cylindrical portion 86 to cover the nozzle 83 with the nozzle cap 81. The inner surface of the nozzle cap 81 and the surface of the lower end portion of the cylindrical portion 86 are covered with an inert resin layer 84.

[0121] The outer surface of the nozzle cap 81 is not provided with an inert resin layer, and the cured product of the medical rubber composition is exposed. A vinyl compound is applied to the surface of the cured product, which is the outer surface of the nozzle cap 81, and ultraviolet irradiation is performed. Since the friction coefficient and adhesiveness of the outer surface of the nozzle cap 81 are reduced, the problem of nozzle caps sticking to each other is improved.

Examples

[0122] Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and any modifications and embodiments within the scope not departing from the gist of the present invention are all included in the scope of the present invention.

[0123] [Production of medical rubber articles] The materials shown in Table 1 were kneaded at 60 °C for 20 minutes using an open roll to prepare a medical rubber composition. After crosslinking the obtained medical rubber composition under molding conditions of 170 °C for 15 minutes, it was punched out into a circular slab (cured product of the medical rubber composition) with a diameter of 28 mm and a thickness of 2 mm. Using 1-octadecene as the vinyl compound represented by the general formula (1), it was dissolved in hexane as a solvent to prepare a 1-octadecene-containing hexane solution so as to have the concentration shown in Table 1, and it was applied to the circular slab by spraying so as to have the adhesion amount shown in Table 1, and then naturally dried to obtain a test piece for ultraviolet irradiation. Thereafter, under a nitrogen atmosphere, the test piece for ultraviolet irradiation was irradiated with vacuum ultraviolet rays (wavelength: 172 nm) so as to have the integrated illuminance shown in Table 1, rinsed with hexane, and naturally dried. Ultraviolet irradiation conditions · Irradiation device: Electrodeless excimer 172 nm irradiation device (manufactured by M.D. Com Co., Ltd.) · Distance between the surface of the cured product and the lamp: 7 mm · Arrival intensity of ultraviolet rays: 57.9 mW / cm 2 / sec

[0124]

Table 1

[0125] Details of the compounding materials used are as follows. Chlorinated butyl rubber: Exxon (registered trademark) Chlorobutyl 1066 manufactured by ExxonMobil Corporation (chlorine content rate: 1.25 wt%) General-purpose butyl rubber: Exxon (registered trademark) Butyl 268 manufactured by ExxonMobil Corporation (degree of unsaturation: 2.30 mol%) Triazine derivative: Disnet DB manufactured by Sankyo Kasei Co., Ltd. Sulfur: Insoluble sulfur (Seimi OT) manufactured by Nippon Dry Distillation Industry Co., Ltd. Zinc oxide: Active zinc white AZO manufactured by Shoindo Chemical Industry Co., Ltd. Magnesium oxide: Mag Sarrant 150s manufactured by Kyowa Chemical Industry Co., Ltd. Dithiocarbamate: Nocceler (registered trademark) ZTC manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

[0126] [Evaluation method] (1) Coefficient of friction (Measurement of static and kinetic friction coefficients) Figure 8 is an explanatory diagram showing a method for measuring the coefficient of friction using a static and kinetic friction coefficient measuring machine TL201 (manufactured by TAILAB) for the medical rubber article prepared above (a circular slab with a thickness of 2 mm and a diameter of 28 mm after ultraviolet irradiation). The measurement sample 63 is fixed to the lower stage 64, and a 10 g weight 61 is placed on a dedicated probe with a SUS ball 62 having a diameter of 10 mm to bring the surface of the measurement sample 63 into contact with the SUS ball 62. Then, the stage 64 is moved in the direction of the arrow at a speed of 10 mm / second for a distance of 20 mm. The value obtained by dividing the frictional force F generated at that time by the load (vertical resistance) N was defined as the coefficient of friction μ. (μ = F / N) Note that the coefficient divided by the average vertical resistance N1 for a moving distance of 20 mm was defined as the kinetic friction coefficient, and the coefficient divided by the maximum average vertical resistance N2 for a moving distance of 20 mm was defined as the static friction coefficient. (Evaluation of static friction coefficient) The static friction coefficient was evaluated according to the following evaluation criteria. ○: The static friction coefficient is less than 1.50. ×: The static friction coefficient is 1.50 or more. (Evaluation of kinetic friction coefficient) The kinetic friction coefficient was evaluated according to the following evaluation criteria. ○: The kinetic friction coefficient is less than 1.30. ×: The kinetic friction coefficient is 1.30 or more.

[0127] (2) Adhesion test (Measurement of tack value) For the medical rubber article prepared above (a circular slab with a thickness of 2 mm and a diameter of 28 mm after ultraviolet irradiation), using a testing machine EZ-SX (manufactured by Shimadzu Corporation), the medical rubber article was fixed to a dedicated jig on the lower side, the upper metal Φ10 mm SUS probe was pressed against the surface of the medical rubber article, after reaching the set pressure (10 N), it was held for 10 seconds, then raised upward at a speed of 10 mm / second, and the peak value of the adhesive force generated between the probe and the cured product of the rubber composition was defined as the tack value. n = 5 was measured, and the average value of n = 3 excluding the maximum and minimum was taken as the tack value. <Evaluation of Adhesiveness> The adhesiveness was evaluated according to the following evaluation criteria. 〇: The tack value is 0.5 N or less. ×: The tack value exceeds 0.5 N.

[0128] (3) Comprehensive Evaluation 〇: The evaluation results of the friction coefficient and the adhesiveness are 〇. ×: Both the evaluation result of the friction coefficient and the evaluation result of the adhesiveness are ×.

[0129] The measurement results and evaluation results of the friction coefficient and the adhesiveness are shown in Table 1. From Table 1, it can be seen that the medical rubber article obtained by the production method of the present invention has a reduced surface friction coefficient and adhesiveness.

Industrial Applicability

[0130] The production method of the present invention can provide a medical rubber part with a reduced surface friction coefficient and adhesiveness. The medical rubber article of the present invention can be suitably used as a medical rubber article that requires a low friction coefficient and low adhesiveness (particularly good slidability).

[0131] A preferred embodiment (1) of the present invention is a step of bringing a vinyl compound represented by the following general formula (1) into contact with a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer, and a step of irradiating the cured product after contact with the vinyl compound with ultraviolet rays, and a method for producing a medical rubber article characterized by including the above steps. R-CH=CH2(1) [In the formula, R represents an alkyl group having 6 or more carbon atoms.]

[0132] A preferred embodiment (2) of the present invention is a method for producing a medical rubber article according to embodiment (1), wherein R in the general formula (1) is an alkyl group having 6 to 20 carbon atoms.

[0133] A preferred embodiment (3) of the present invention is a method for manufacturing a medical rubber article of embodiment (1) or 2, in which a vinyl compound-containing liquid having a vinyl compound concentration of 2.0 g / L to 25.0 g / L is applied to the cured product to bring the vinyl compound into contact therewith.

[0134] A preferred embodiment (4) of the present invention is a method for manufacturing a medical rubber article according to any one of embodiments (1) to (3), in which the wavelength of the ultraviolet light is 160 nm to 380 nm.

[0135] A preferred embodiment (5) of the present invention is that the integrated illuminance of ultraviolet light on the cured product after contact with the vinyl compound is 1000 mJ / cm 2 ~50000 mJ / cm 2 and is a method for manufacturing a medical rubber part according to any one of embodiments (1) to (4).

[0136] A preferred embodiment (6) of the present invention is a method for manufacturing a medical rubber article according to any one of embodiments (1) to (5), in which the irradiation with ultraviolet light is performed in a nitrogen atmosphere.

[0137] A preferred embodiment (7) of the present invention is a method for manufacturing a medical rubber article according to any one of embodiments (1) to (6), in which the halogenated butyl rubber is at least one selected from the group consisting of chlorinated butyl rubber, brominated butyl rubber, and brominated copolymers of isobutylene and p-methylstyrene.

[0138] A preferred embodiment (8) of the present invention is a method for manufacturing a medical rubber article according to any one of embodiments (1) to (7), in which (a) the base polymer consists only of halogenated butyl rubber.

[0139] A preferred embodiment (9) of the present invention is a method for manufacturing a medical rubber article according to any one of embodiments (1) to (8), in which the medical rubber article is a rubber stopper for a vial, a cap for a syringe, a plunger stopper for a syringe, or a rubber stopper for a vacuum blood collection tube.

[0140] A preferred embodiment (10) of the present invention is a method for manufacturing a medical rubber article according to any one of embodiments (1) to (9), wherein at least a part of the surface of the cured product of the medical rubber composition is coated with an inert resin layer, and at least a part of the surface of the cured product that is not coated with the inert resin layer and is exposed is brought into contact with a vinyl compound and irradiated with ultraviolet light.

[0141] A preferred embodiment (11) of the present invention is a method for manufacturing a medical rubber article according to embodiment (10), wherein the medical rubber article has a liquid contact surface portion facing a chemical solution and a sliding surface portion in contact with a syringe barrel, the liquid contact surface portion is coated with an inert resin layer, and the sliding surface portion is not coated with the inert resin layer and is exposed, and is a plunger stopper for a syringe.

[0142] A preferred embodiment (12) of the present invention is a method for manufacturing a medical rubber article according to embodiment (10) or (11), wherein the inert resin layer is a layer made of a fluororesin.

[0143] A preferred embodiment (13) of the present invention is a method for manufacturing a medical rubber article according to embodiment (10) or (11), wherein the inert resin layer is a layer made of a non-fluororesin.

[0144] A preferred embodiment (14) of the present invention is a medical rubber article, wherein one end of an alkyl chain having 8 or more carbon atoms is chemically bonded to the surface of a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer.

[0145] A preferred embodiment (15) of the present invention is a medical rubber part according to embodiment (14), wherein the alkyl chain is linear.

Claims

1. (a) A step of bringing a vinyl compound represented by the following general formula (1) into contact with a cured product of a medical rubber composition containing a halogenated butyl rubber as a base polymer; A method for producing a medical rubber article, comprising a step of irradiating the cured product after contact with the vinyl compound with ultraviolet rays. R-CH=CH ２ (1) [In the formula, R represents an alkyl group having 6 or more carbon atoms.]

2. The method for producing a medical rubber article according to claim 1, wherein R in the general formula (1) is an alkyl group having 6 to 20 carbon atoms.

3. The method for producing a medical rubber article according to claim 1, wherein the vinyl compound is brought into contact by applying a vinyl compound-containing liquid having a concentration of the vinyl compound of 2.0 g / L to 25.0 g / L to the cured product.

4. The method for producing a medical rubber article according to claim 1, wherein the wavelength of the ultraviolet rays is 160 nm to 380 nm.

5. The integrated illuminance of ultraviolet rays on the cured product after contact with the vinyl compound is 1000 mJ / cm ２ to 50000 mJ / cm ２ The method for producing a medical rubber part according to claim 1, wherein the integrated illuminance is in the range of 1000 mJ / cm to 50000 mJ / cm

6. The method for producing a medical rubber article according to claim 1, wherein the irradiation with ultraviolet rays is performed in a nitrogen atmosphere.

7. The method for producing a medical rubber article according to claim 1, wherein the halogenated butyl rubber is at least one selected from the group consisting of chlorinated butyl rubber, brominated butyl rubber, and brominated copolymers of isobutylene and p-methylstyrene.

8. The method for producing a medical rubber article according to claim 1, wherein (a) the base polymer consists only of a halogenated butyl rubber.

9. The method for producing a medical rubber article according to claim 1, wherein the medical rubber article is a rubber stopper for a vial, a cap for a syringe, a plunger stopper for a syringe, or a rubber stopper for a vacuum blood collection tube.

10. At least a part of the surface of the cured product of the medical rubber composition is coated with an inert resin layer, and a vinyl compound is brought into contact with at least a part of the surface of the cured product that is not coated with the inert resin layer and is exposed, and irradiated with ultraviolet rays. The method for producing a medical rubber article according to claim 1.

11. The method for producing a medical rubber article according to claim 10, wherein the medical rubber article has a liquid contact surface facing a chemical solution and a sliding surface in contact with a syringe barrel, the liquid contact surface is coated with an inert resin layer, and the sliding surface is not coated with an inert resin layer and is exposed, and is a plunger stopper for a syringe.

12. The method for producing a medical rubber article according to claim 10, wherein the inert resin layer is a layer made of a fluororesin.

13. The method for manufacturing a medical rubber article according to claim 10, wherein the inert resin layer is a layer made of a non-fluorine resin.

14. (a)A medical rubber article, characterized in that one end of an alkyl chain having 8 or more carbon atoms is chemically bonded to the surface of a cured product of a medical rubber composition containing halogenated butyl rubber as a base polymer.

15. The medical rubber article according to claim 14, wherein the alkyl chain is linear.

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