Syringe gasket and syringe equipped with it

Abstract

A gasket 1, which is constructed so as to come into slidable contact in a liquid-tight manner within an external plastic cylinder of a syringe, includes a gasket body 2 made of an elastic material and a coating layer 3 provided at least at the part which comes into contact with the syringe, wherein the coating layer 3 is an elastic cured coating layer comprising, as a main component, a silicone-based resin, which comprises a condensate of a reactive silicone having silanol groups at both terminals and has a siloxane bond derived from the silanol groups, and also containing a silane coupling agent and a carbodiimide compound.

Description

Technical Field

[0001] The present invention relates to a gasket for syringes having stable sliding properties and a syringe provided with the gasket.

Background Art

[0002] Conventionally, prefilled syringes pre-filled with medicinal solutions have been used for reasons such as preventing medication mix-ups, preventing nosocomial infections, improving disposability, and increasing the efficiency of hospital operations. Regardless of the type of syringe used in prefilled syringes, a syringe generally consists of an outer barrel, a gasket slidable within the syringe, and a plunger for moving the gasket. In most syringes, silicone oil or the like is applied as a lubricant to the sliding portion on the outer surface of the gasket or the inner surface of the syringe, in order to improve the sliding property of the gasket and obtain high flow accuracy without causing large turbulence in the discharge of the medicinal solution. However, it is known that interaction with lubricants such as silicone oil may occur depending on the medicinal solution. Furthermore, when a medicinal solution is stored for a long period after filling, the interaction may cause deterioration of the medicinal solution, so some drugs are difficult to be prefilled. Particularly for prefilled syringes that are stored for a long period with the medicinal solution filled therein, there is a demand for a lubricant-free prefilled syringe that can maintain the stability of the medicinal solution.

[0003] Therefore, to solve the above problem, prefilled syringes that eliminate the need for lubricant by coating the surface of the gasket with a fluororesin, which is a material having a lower coefficient of friction than the gasket body material, have been proposed in Patent Document 1 (JP A 62-32970), Patent Document 2 (JP A 2002-089717, US Patent 7111848) and the like. Furthermore, the applicant has proposed Patent Document 3 (Japanese Patent Publication No. 2004-321614) relating to a gasket having a coating layer composed of a fluororesin, a silicon-based resin, and a urethane-based resin, and Patent Document 4 (Japanese Patent Publication No. 2006-167110) relating to a gasket having a coating layer consisting of a film formed from a composition containing a sliding-impeding component and a flexibility-impeding component, and fine particles held in the film to form a rough surface on the gasket. Furthermore, the applicant has proposed a gasket formed to be liquid-tight and slidably in contact with the inside of the outer barrel of a syringe, wherein the gasket comprises a gasket body made of an elastic material and a coating layer provided at least on the portion that contacts the syringe, and the coating layer is made of a composition containing a silicone resin having siloxane bonds derived from the silanol groups, and does not contain solid fine particles (Patent Document 5: WO2009 / 084646). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 62-32970 [Patent Document 2] Japanese Patent Publication No. 2002-089717 (United States Patent No. 7111848, US2004-084852A, US2005-212222A, EP1317937A, WO02-22192) [Patent Document 3] Japanese Patent Publication No. 2004-321614 [Patent Document 4] Japanese Patent Publication No. 2006-167110 [Patent Document 5] WO2009 / 084646 (US2010-324501A, US2015-133873A, EP2226088A) [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The gaskets described in Patent Document 1 (Japanese Unexamined Patent Publication No. 62-32970) and Patent Document 2 (Japanese Unexamined Patent Publication No. 2002-089717, U.S. Patent No. 7111848) can be expected to be effective under certain usage conditions. However, in pre-filled syringe formulations, where high pressure is required to dispense the drug solution or a syringe pump is needed to dispense the drug solution in small amounts stably over a long period of time with extremely high precision, there is still a trade-off between the basic performance requirements for syringes: liquid tightness and sliding properties. There is a need for syringes that can achieve a high level of balance between these performances and possess even higher functionality. In other words, when administering drug solutions using a syringe pump, if the drug solution is dispensed under extremely slow conditions that are not visible to the naked eye (for example, in a syringe with a diameter of approximately 24 mm, the movement speed when dispensing at 1 mL / hour is approximately 2 mm / hour), an unstable dispensing state called pulsation tends to occur, which could hinder the accurate administration of the drug solution.

[0006] Furthermore, the gaskets described in Patent Document 3 (Japanese Unexamined Patent Publication No. 2004-321614) and Patent Document 4 (Japanese Unexamined Patent Publication No. 2006-167110) are liquid-tight and have stable sliding properties without the application of lubricant to the sliding surface. However, the former has manufacturing and cost problems due to the wide variety of materials used to form the coating layer. In the latter, there was further a problem of difficulties arising during the formation of the coating layer due to fine particles held in the coating layer.

[0007] Furthermore, the gasket described in Patent Document 5 (WO2009 / 084646) is liquid-tight and has stable sliding properties without the application of lubricant to the sliding surface. However, the inventors of the present invention have found that in syringe systems subjected to higher pressure or syringe applications involving repeated sliding, a stronger coating is desirable.

[0008] Therefore, the present invention solves the above problems and provides a gasket that has stable sliding properties without applying a lubricant to the sliding surface and exhibits extremely little peeling of the applied coating, as well as a syringe equipped with the same. [Means for solving the problem]

[0009] The following will achieve the above objectives: Syringe Cyclic polyolefins A gasket formed to make liquid-tight sliding contact with the inside of a manufactured outer cylinder, the gasket comprising a gasket body made of an elastic material and a coating layer provided at least on the portion that contacts the syringe, the coating layer being an elastic curing coating layer made of a condensate of reactive silicone having silanol groups at both ends, mainly composed of a silicone resin having siloxane bonds derived from the silanol groups, and containing a carbodiimide compound together with a silane coupling agent. Furthermore, the silane coupling agent has a functional group that reacts with the carbodiimide group of the carbodiimide compound, the carbodiimide compound is a carbodiimide having two or more carbodiimide groups, and the gasket having the elastic curing coating layer is such that when the side surface of the gasket having the elastic curing coating layer is pressed vertically against an annular polyolefin plate and slid horizontally at a speed of 100 mm / min for 90 mm with a force of 10 N, no residue of the elastic curing coating layer is observed. Syringe gasket.

[0010] The following will achieve the above objectives: Cyclic polyolefins The outer cylinder and the aforementioned Made from cyclic polyolefin A syringe comprising a gasket according to claim 1 or 2, slidably housed within an outer cylinder, and a plunger attached to or attachable to the gasket. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a front view of a gasket according to an embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view of the gasket shown in Figure 1. [Figure 3] Figure 3 is a plan view of the gasket shown in Figure 1. [Figure 4] Figure 4 is a bottom view of the gasket shown in Figure 1. [Figure 5] Figure 5 is a cross-sectional view of a pre-filled syringe using the gasket shown in Figure 1. [Figure 6] FIG. 6 is a photograph showing an experimental result using a gasket which is an embodiment of the present invention. [Figure 7] FIG. 7 is a photograph showing an experimental result using a gasket of a comparative example. MODE FOR CARRYING OUT THE INVENTION

[0012] A gasket which is an embodiment of the present invention will be described. FIG. 1 is a front view of a gasket which is an embodiment of the present invention. FIG. 2 is a cross-sectional view of the gasket shown in FIG. 1. FIG. 3 is a plan view of the gasket shown in FIG. 1. FIG. 4 is a bottom view of the gasket shown in FIG. 1. FIG. 5 is a cross-sectional view of a prefilled syringe using the gasket shown in FIG. 1. The gasket 1 of the present invention is a gasket formed so as to be in liquid-tight and slidable contact within a plastic outer cylinder of a syringe. The gasket 1 includes a gasket body (core portion) 2 made of an elastic body, and a coating layer 3 provided at least in a portion in contact with the syringe, wherein the coating layer 3 is composed of a condensate of reactive silicone having silanol groups at both terminals, is mainly composed of a silicone-based resin having a siloxane bond derived from silanol groups, and is an elastic cured coating layer containing a carbodiimide compound together with a silane coupling agent.

[0013] The gasket of the present invention will be described with reference to embodiments. The gasket 1 of this embodiment is a gasket 1 for a syringe, and is liquid-tightly and slidably housed inside an outer cylinder 11 for a syringe. Further, the gasket 1 includes the coating layer 3 provided in a portion in contact with the outer cylinder 11. The gasket 1 includes a gasket body (core portion) 2, and the coating layer 3 provided at least on an outer surface of the gasket body 2 at a portion in contact with an inner surface of the outer cylinder. Note that the coating layer 3 may be provided on the entire outer surface of the gasket body 2.

[0014] As shown in Figures 1, 2, and 5, the gasket body 2 of the syringe gasket 1 comprises a main body portion 5 extending to substantially the same outer diameter, a tapered portion 6 provided on the tip side of the main body portion 5 that tapers in diameter toward the tip, a plunger mounting portion 4 provided inside the main body portion 5 from the base end toward the tip, a tip-side annular rib 7a provided on the tip side surface of the main body portion 5, and a rear-end-side annular rib 7b provided on the rear end side surface of the main body portion 5. As shown in Figures 2 and 4, the plunger mounting portion 4 is a substantially cylindrical recess extending from the base end to near the tip end inside the main body portion 5, and a threaded portion 8 that can be screwed into the threaded portion formed on the tip end of the plunger is provided on the side surface of the recess. The tip surface of the recess is formed to be substantially flat. Note that the plunger mounting portion is not limited to a threaded portion, but may also be an engaging portion that engages with the tip end of the plunger.

[0015] The annular ribs 7a and 7b are manufactured to be slightly larger than the inner diameter of the syringe outer cylinder 11, so that they undergo compressive deformation within the outer cylinder 11. In this embodiment, two annular ribs are provided, but one or three or more may also be provided. The gasket body (core) 2 is preferably made of an elastic material. While not particularly limited, examples of elastic materials include various rubber materials (especially vulcanized ones) such as natural rubber, isoprene rubber, butyl rubber, chloroprene rubber, nitrile-butadiene rubber, styrene-butadiene rubber, and silicone rubber; styrene elastomers; hydrogenated styrene elastomers; and mixtures of these styrene elastomers with polyolefins such as polyethylene, polypropylene, polybutene, and α-olefin copolymers; oils such as liquid paraffin and process oil; and powdered inorganic materials such as talc, cast, and mica. Furthermore, polyvinyl chloride elastomers, olefin elastomers, polyester elastomers, polyamide elastomers, polyurethane elastomers, and mixtures thereof can also be used as constituent materials. Diene rubbers and styrene elastomers are particularly preferred as constituent materials because they possess elastic properties and can be sterilized by gamma rays, electron beams, and high-pressure steam.

[0016] The coating layer 3 only needs to be provided on at least the annular rib portion. Specifically, the coating layer 3 needs to be provided on the leading annular rib 7a and the trailing annular rib 7b portion. The thickness of the coating layer 3 is preferably 1 to 30 μm, and more preferably 3 to 10 μm. If it is 1 μm or more, it will exhibit the necessary sliding performance, and if it is 30 μm or less, it will not affect the elasticity of the gasket. As the silicone resin, both solvent-based resins dissolved in organic solvents and aqueous-based resins emulsified and dispersed in water can be used, but aqueous-based resins are preferred in terms of their effect on the gasket material and their suitability as a chemical solution storage container. The coating layer 3 is made of a resin composed of a material with a lower coefficient of friction than the elastic material that constitutes the gasket body 1.

[0017] The coating layer 3 is an elastic curing coating layer consisting of a condensate of reactive silicone having silanol groups at both ends, with a silicone resin having siloxane bonds derived from the silanol groups as its main component, and containing a carbodiimide compound together with a silane coupling agent. Furthermore, the composition containing the reactive silicone resin is preferably a thermosetting silicone resin or a room-temperature curing silicone resin, and is particularly preferred to be a thermosetting silicone resin from the viewpoint of workability and other factors. As the reactive silicone, one having silanol groups at both ends is used. When a polysiloxane-based silicone having silanol groups at both ends is used as the reactive silicone, the condensate of this reactive silicone will have siloxane bonds throughout the entire main chain.

[0018] Furthermore, as reactive silicones having silanol groups at both ends, polysiloxane-based silicones having silanol groups at both ends, such as silanol polydimethylsiloxane at both ends, silanol polydiphenylsiloxane at both ends, and silanol diphenylsiloxane-dimethylsiloxane copolymer at both ends, are preferred. In addition, the form of the reactive silicone is not particularly limited, but polysiloxanes consisting of the above-mentioned reactive silicone siloxane compounds or condensates thereof can be dispersed, emulsified, and dissolved in an aqueous medium. Copolymer emulsions obtained by copolymerizing an alkoxysilyl group-containing vinyl monomer with other vinyl monomers as needed, and emulsions obtained by compounding polysiloxane with an organic polymer can also be used.

[0019] Furthermore, the resin composition forming the coating layer 3 contains a silane coupling agent. In other words, the elastic curing coating layer 3 contains a silane coupling agent. The silane coupling agent is preferably at least one selected from alkylalkoxysilanes, phenylalkoxysilanes, aminoalkylalkoxysilanes, or glycidoxyalkylalkoxysilanes.

[0020] Furthermore, it is preferable that the resin composition forming the coating layer 3 contains alkylalkoxysilane or phenylalkoxysilane as a first silane coupling agent, and further contains aminoalkylalkoxysilane and / or glycidoxyalkylalkoxysilane as a second silane coupling agent. Furthermore, it is preferable that the resin composition forming the coating layer 3 contains alkylalkoxysilane or phenylalkoxysilane as a first silane coupling agent, aminoalkylalkoxysilane as a second silane coupling agent, and glycidoxyalkylalkoxysilane as a third silane coupling agent.

[0021] Alkylalkoxysilanes have at least one alkyl group having 1 to 20 carbon atoms and at least one alkoxy group having 1 to 4 carbon atoms. Methyltrimethoxysilane, methyltriethoxysilane, methyltriisobutoxysilane, methyltributoxysilane, methylsec-trioctyloxysilane, isobutyltrimethoxysilane, cyclohexylmethyldimethoxysilane, diisopropyldimethoxysilane, propyltrimethoxysilane, diisobutyldimethoxysilane, n-octylmethoxysiloxane, ethyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octamethylcyclotetrasiloxane, methyltri(acryloyloxyethoxy)silane, octyltriethoxysilane, lauryltriethoxysilane, stearyltrimethoxysilane, stearyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxy Silane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyl Suitable candidates include triethoxysilane, pentadecyltrimethoxysilane, hexadecyltrimethoxysilane, heptadecyltrimethoxysilane, octadecyltrimethoxysilane, nonadecyltrimethoxysilane, nonadecyltriethoxysilane, eicosyltrimethoxysilane, and eicosyltriethoxysilane.

[0022] Suitable alkylphenoxysilanes include, for example, methyltriphenoxysilane. Suitable phenoxyalkoxysilanes include phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. In addition, alkylalkoxysilanes such as methyltri(glycidyloxy)silane, trimethylchlorosilane, dimethylchlorosilane, methyltrichlorosilane, tetraethoxysilane, heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, and tetrapropoxysilane can also be used.

[0023] Suitable aminoalkylalkoxysilanes include 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-phenylaminopropyltrimethoxysilane.

[0024] Suitable glycidoxyalkylalkoxysilanes include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Furthermore, silane compounds such as 3-ureidopropyltriethoxysilane, diallyldimethylsilane, n-octyldimethylchlorosilane, tetraethoxysilane, and trifluoropropyltrimethoxysilane may be used as silane coupling agents.

[0025] Furthermore, the composition forming the coating layer 3 may contain a first and a second silane coupling agent. The first silane coupling agent is preferably selected from alkylalkoxysilane, alkylphenoxysilane, and phenylalkoxysilane. The second silane coupling agent is preferably aminoalkylalkoxysilane or glycidoxyalkylalkoxysilane. Additionally, the composition forming the coating layer may contain a first, second, and a third silane coupling agent. The first silane coupling agent is preferably selected from alkylalkoxysilane, alkylphenoxysilane, and phenylalkoxysilane. The second silane coupling agent is preferably aminoalkylalkoxysilane, and the third silane coupling agent is preferably glycidoxyalkylalkoxysilane.

[0026] Furthermore, the resin composition forming the coating layer 3 contains a carbodiimide compound. In other words, the elastic curing coating layer 3 contains a carbodiimide compound. In the resin composition forming the elastic curing coating layer 3, the silicone resin or silane coupling agent has a functional group that reacts with the carbodiimide group of the carbodiimide compound. Alternatively, in the resin composition forming the elastic curing coating layer 3, the silicone resin and silane coupling agent may also have a functional group that reacts with the carbodiimide group of the carbodiimide compound.

[0027] The functional group that reacts with the carbodiimide group is preferably at least one selected from a carboxyl group, a hydroxyl group, an amino group, an amide group, a sulfonic acid group, and a phosphate group. The carbodiimide compound is preferably a compound having two or more carbodiimide groups (-N=C=N-). The carbodiimide group functions as a crosslinking functional group. Furthermore, the carbodiimide compound may also have one or more isocyanate groups derived from the raw material polyisocyanates (Q) in addition to the carbodiimide group.

[0028] In the elastic curing coating layer 3, the functional groups that react with the carbodiimide groups of the silicone resin and / or silane coupling agent are bonded to the carbodiimide groups of the carbodiimide compound. In particular, if the carbodiimide compound has two or more carbodiimide groups, the carbodiimide compound will bond to the carbodiimide groups of the silicone resin and / or silane coupling agent at two locations, forming a strong coating layer.

[0029] The carbodiimide compound is preferably a polycarbodiimide or a cyclic carbodiimide, but polycarbodiimide is particularly preferred. Furthermore, aliphatic polycarbodiimide compounds are preferred. As for the polycarbodiimide, those with a number-average molecular weight of 500 to 20000 are preferred.

[0030] Examples of polycarbodiimide compounds include aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide), as well as poly(phenylenecarbodiimide), poly(naphthylenecarbodiimide), poly(trinecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), and poly(triethylphenylene Aromatic polycarbodiimides such as poly(4,4'-dicyclohexylmethanecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), poly[methylenebis(methylphenylene)carbodiimide], and also poly(4,4'-dicyclohexylmethanecarbodiimide), poly(N,N' -di-2,6-diisopropylphenylcarbodiimide), poly(1,3,5-triisopropylphenylene-2,4-carbodiimide, urethane condensates of polyoxyalkylene alkyl (or alkenyl) (C=8~24) ether and polyoxyalkylene (n=1~300) glycol with hexamethylene diisocyanate [or tolylene diisocyanate, xylylene diisocyanate, bis(isocyanatophenyl)methane], lauryl alcohol and hexamethylene diisocyanate and Examples include condensates of triethylene diisocyanate, alkyl-substituted carbodiimide compounds, urethane condensates of dioxyethylene stearyl ether and polyethylene glycol (n=5) with hexamethylene diisocyanate, urethane condensates of tetraoxyethylene stearyl ether and polyethylene glycol with hexamethylene diisocyanate, and urethane condensates of dioxyethylene lauryl ether and polyethylene glycol (n=5) with diphenylmethane diisocyanate.

[0031] Furthermore, carbodiimide compounds can be, for example, water-soluble, those that form emulsions in water, or those that form dispersions in water. Any of these may be used, or a mixture of several may be used. In this invention, the carbodiimide compound is preferably a water-soluble carbodiimide compound. The polycarbodiimide may also be a polycarbodiimide in which the ends are sealed with a water-soluble polymer.

[0032] The content of the carbodiimide compound in the resin composition forming the coating layer 3 is preferably 0.01 to 0.2 parts by weight, and particularly preferably 0.01 to 0.05 parts by weight. By having the coating layer 3 described above, the gasket 1 of the present invention has stable sliding properties without the need to apply lubricant to the sliding surface, and can maintain airtightness within the drug storage space. Furthermore, since the coating layer has sufficient strength, it does not peel off or partially detach from the gasket body 2.

[0033] The elastic curing coating layer 3 is preferably a thermosetting elastic curing coating layer. Furthermore, the coating layer is preferably 1 to 30 μm thick, and particularly preferably 3 to 10 μm thick. Furthermore, it is preferable that the coating layer has an initial sliding resistance value that is less than or equal to the maximum dynamic sliding resistance value. In addition, it is preferable that the dynamic sliding resistance value of the gasket during low-speed sliding (100 mm / min) inside the outer cylinder is 20 N or less for syringes with a capacity of 1 to 20 mL, 100 N or less for syringes with a capacity exceeding 20 mL but less than 100 mL, and 150 N or less for syringes with a capacity of 100 mL or more.

[0034] Next, the method for forming the coating layer 3 will be described. The coating layer is formed by preparing a coating solution by dispersing and suspending the above-mentioned silicone resin and carbodiimide compound in the required composition and amount in purified water. This coating solution is then applied to a clean gasket surface and cured. At this time, the method of applying it to the gasket surface can be conventionally known methods such as immersion or spraying. In particular, it is preferable to spray the coating solution while the object to be coated is rotating (specifically, 100 to 600 rpm). Furthermore, when spraying, it is preferable to heat-treat the part of the gasket to be coated to about 60 to 120°C beforehand. By doing so, the coating solution adheres quickly to the surface of the object to be coated without causing water repellency.

[0035] While room temperature curing is acceptable, heat curing is preferred. The heat curing method is not particularly limited as long as it does not alter or deform the gasket substrate, but examples include hot air drying and infrared drying ovens. Alternatively, conventionally known methods such as vacuum drying can be used. The thickness of the formed coating layer is approximately 1 to 30 μm, preferably 3 to 10 μm. Such a coating layer can be easily formed by appropriately controlling the concentration of the mixed solution, or by using immersion or spraying methods.

[0036] Furthermore, a catalyst to accelerate thermal curing may be used as an additive in the preparation of the coating solution containing the silicone resin. Acids, alkalis, amines, organic salts of metals, titanates, and borates can be used as catalysts, but zinc octylate, iron octylate, or organic acid salts such as cobalt, tin, and lead are preferred. In particular, organic salts of tin that can be used include bis(2-ethylhexanoate)tin, bis(neodecanoate)tin, di-n-butylbis(2-ethylhexylmalate)tin, di-n-butylbis(2,4-pentanedionate)tin, di-n-butylbutoxychlorotin, di-n-butyldiacetoxytin, di-n-butyldilauryl tin, dimethyldineodecanoate tin, dimethylhydroxy(oleate)tin, and dioctyldilauryl tin.

[0037] Furthermore, in preparing a coating solution containing a silicone resin, additives such as surfactants or alcohols may be used to ensure uniform emulsification, suspension, and dispersion of the solution. The surfactant is preferably an anionic surfactant. Any anionic surfactant is acceptable, but examples include aliphatic monocarboxylates, polyoxyethylene alkyl ether carboxylates, N-acyl sarcosinates, N-acyl glutamates, dialkyl sulfosuccinates, alkane sulfons, alpha-olefin sulfons, linear alkylbenzene sulfons, molecular chain alkylbenzene sulfons, naphthalene sulfonate-formaldehyde condensates, alkylnaphthalene sulfons, N-methyl-N-acyl taurine, alkyl sulfates, polyoxyethylene alkyl ether sulfates, oil sulfates, alkyl phosphates, polyoxyethylene alkyl ether sulfates, and polyoxyethylene alkylphenyl ether sulfates.

[0038] Nonionic surfactants may also be used. Any nonionic surfactant can be used, but examples include polyoxyethylene alkyl ethers, polyoxyalkylene derivatives, polyoxyethylene alkylphenyl ethers, polyoxyethylene sorbitan fatty acid esters, fatty acid alkanolamides, glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene alkylamines, and alkyl alkanolamides.

[0039] Furthermore, the syringe 10 of the present invention comprises an outer cylinder 11, a gasket 1 slidably housed within the outer cylinder 11, and a plunger 17 attached to or attachable to the gasket 1.

[0040] Specifically, as shown in Figure 5, the syringe 10 consists of a syringe outer cylinder 11 having a needle attachment portion 15 at its tip and a flange 16 facing it at its rear end, a syringe gasket 1 that can slide liquid-tight and airtightly along the inner surface 12 of the syringe outer cylinder 11, a plunger 17 that is attached to or can be attached to the syringe gasket 1, a sealing member 18 that seals the needle attachment portion 15 of the syringe outer cylinder 11, and a drug storage portion 19 that stores the drug 26 formed between the sealing member 18, the inner surface 12 of the outer cylinder, and the syringe gasket 1.

[0041] Furthermore, an injection needle may be attached to the injection needle attachment portion 15 instead of the sealing member 18. Also, as shown in Figure 5, the sealing member may be of a type having a puncture portion through which a double-ended needle can be directly inserted, or it may be of a type in which the drug can only be discharged after the sealing member is removed. The gasket 1 is provided with the coating layer 3 described above. In this syringe 10, it is preferable that the dynamic sliding resistance value of the gasket 1 at low-speed sliding (100 mm / min) within the outer cylinder 11 is 20 N or less for syringes with a capacity of 1 to 20 mL, and 150 N or less for syringes with a capacity of 100 mL or more. Such a low dynamic sliding resistance value can be obtained by the gasket 1 having the coating layer 3 described above.

[0042] In particular, this medical device is a pre-filled syringe 25, consisting of a syringe 10 and a drug 26, as shown in Figure 5. The syringe outer barrel 11 is a cylindrical member with a needle attachment portion 15 at its tip and a flange 16 at its rear end. The syringe outer barrel 11 is made of a transparent or translucent material. Preferably, it is made of a material with low oxygen permeability and water vapor permeability. Furthermore, it is preferable that the forming material has a glass transition temperature or melting point of 110°C or higher.

[0043] The forming material for the outer cylinder 11 is preferably a variety of commonly used rigid plastic materials, such as polyolefins including polypropylene, polyethylene, poly(4-methylpentene-1), and cyclic polyolefins; polyesters including polyethylene terephthalate, polyethylene naphthalate, and amorphous polyarylate; polystyrene, polyamide, polycarbonate, polyvinyl chloride, acrylic resin, acrylonitrile-butadiene-styrene copolymer, and amorphous polyetherimide. In particular, polypropylene, poly(4-methylpentene-1), cyclic polyolefins, polyethylene naphthalate, and amorphous polyetherimide are preferred in terms of transparency and heat sterilization resistance. These resins can be used not only for syringe outer cylinders but also for containers capable of holding pharmaceuticals. Furthermore, glass may also be used as the forming material.

[0044] Furthermore, as shown in Figure 5, the plunger 17 comprises a main body portion 20 extending in the axial direction with a cross-shaped cross-section, a plunger-side threaded portion 21 provided at the tip of the plunger 17 that screws into the plunger mounting portion 4, a disc-shaped gasket pressing portion provided between the plunger-side threaded portion 21 and the main body portion 20, a pressing disc portion 22 provided at the rear end of the main body portion 20, and a disc-shaped rib provided in the middle of the main body portion 20.

[0045] The syringe 10 in this embodiment contains a drug 26. The drug 26 may be a liquid, a powder, or a solid such as a freeze-dried agent. However, it is more preferable to use a drug that is poorly water-soluble, highly adsorbent, contains a surfactant, has low viscosity and high penetration power, as this eliminates the need for silicone oil. Furthermore, if the coating layer 3 is provided on the part that comes into contact with the contained drug, drug adsorption can be prevented. Furthermore, it is preferable to use rigid or semi-rigid resins such as polyvinyl chloride, high-density polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polycarbonate, or acrylic resin as the constituent materials for the plunger 17 and the sealing member 18. [Examples]

[0046] Specific examples of the present invention will be described below. (Example 1) Using butyl rubber, a gasket core (gasket core member) for a 100 mL syringe was fabricated in the shape shown in Figures 1 and 2. The core was formed by press molding a vulcanizable rubber composition, which was butyl rubber blended with additives. The resulting core had a length of 18 mm, an outer diameter of 33 mm at the annular rib portions at the front and rear ends, an outer diameter of 32 mm at the portion with the same outer diameter between the front and rear annular ribs, a length (depth) of 10 mm for the plunger mounting recess with an internal female thread, an inner diameter of 20 mm at the front end of the plunger mounting recess, and an inner diameter of 23 mm at the rear end.

[0047] A1: Silicone resin 1) Product name 1501 Fluid (manufactured by Toray Dow Corning Co., Ltd.), whose main component is terminally silanol polydimethylsiloxane, 25 parts by weight 2) Product name Z-6366 (manufactured by Toray Dow Corning Co., Ltd.), whose main component is methyltrimethoxysilane, 0.1 parts by weight 3) A mixture of product name Z-6011 (manufactured by Toray Dow Corning Co., Ltd.), whose main component is 3-aminopropyltriethoxysilane, and an ethanol solution of maleic anhydride, 1 part by weight (resin content 50%). 4) Product name Z-6040 (manufactured by Toray Dow Corning Co., Ltd.), whose main component is 3-glycidoxypropyltrimethoxysilane, 0.5 parts by weight

[0048] B: Carbodiimide compound Aqueous solution of polyvalent carbodiimide [Polyvalent carbodiimide compound content 40% by weight, product name Carbodilite V-02, manufactured by Nisshinbo Chemical Co., Ltd., pH 9-12, viscosity (typical value) 100 mPa·s, NCN equivalent (chemical formula weight per 1 mol of carbodiimide group) 590, aqueous solution of hydrophilic group-modified polycarbodiimide compound]

[0049] C: Preparation of the coating solution A silicone resin mixture was prepared by mixing 100 parts by weight of a silicone resin (A1) consisting of the above 1) to 4) with 10 parts by weight of linear alkylbenzene sulfonate sodium. The main component was prepared by adding 29 parts by weight of the above silicone resin mixture and 1 part by weight of dioctyl dilaurate to 66 parts by weight of purified water. Furthermore, 5 parts by weight of the aforementioned carbodiimide compound (B: a mixture of polyvalent carbodiimide compound and water) was added to 100 parts by weight of the main component, and the mixture was stirred to prepare the coating solution.

[0050] Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 1.

[0051] (Example 2) A coating solution was prepared in the same manner as in Example 1, except that 1 part by weight of the above-mentioned carbodiimide compound (B: a mixture of a polyvalent carbodiimide compound and water) was added to 100 parts by weight of the main component in Example 1, and the mixture was stirred to prepare the coating solution. Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 2.

[0052] (Example 3) The following silicone-based resins were used. A2: Silicone resin 1) Product name DMS-S14 (manufactured by GELEST), whose main component is terminally silanol polydimethylsiloxane, 25 parts by weight 2) Product name SIP6560.0 (manufactured by GELEST), whose main component is methyltrimethoxysilane, 0.1 parts by weight 3) A mixture of product name SIA0610.0 (manufactured by GELEST), whose main component is 3-aminopropyltriethoxysilane, and an ethanol solution of maleic anhydride, 1 part by weight (50% resin content) 4) Product name SIG5840.1 (manufactured by GELEST), whose main component is 3-glycidoxypropyltrimethoxysilane, 0.5 parts by weight

[0053] A silicone resin mixture was prepared by mixing 100 parts by weight of a silicone resin (A2) consisting of the above 1) to 4) with 10 parts by weight of linear alkylbenzene sulfonate sodium. A main component was prepared by adding 29 parts by weight of the above silicone resin mixture and 1 part by weight of dioctyl dilaurate to 66 parts by weight of purified water. Furthermore, 5 parts by weight of the carbodiimide compound used in Example 1 (B: a mixture of a polyvalent carbodiimide compound and water) was added to 100 parts by weight of this main component, and the mixture was stirred to prepare the coating solution. Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes. After that, it was rotated around its central axis (300 rpm), and a coating liquid of the above composition (0.2 mL) was spray-applied to the rotating side of the gasket. The gasket was then dried at 100°C for 15 minutes to produce the gasket of the present invention. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 3.

[0054] (Example 4) The coating solution was prepared in the same manner as in Example 3, except that 1 part by weight of the carbodiimide compound used in Example 1 (B: a mixture of a polyvalent carbodiimide compound and water) was added to 100 parts by weight of the main component in Example 3, and the mixture was stirred to prepare the coating solution.

[0055] Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 4.

[0056] (Example 5) The following silicone-based resins were used. A3: Silicone resin 1) Product name YR3204 (manufactured by Momentive Performance Materials Japan LLC), whose main component is a polyalkylphenylsiloxane having a silanol group, 25 parts by weight. 2) Product name TSL8178 (manufactured by Momentive Performance Materials Japan LLC), whose main component is phenyltriethoxysilane, 0.1 parts by weight 3) A mixture of 1 part by weight (50% resin content) of product name TSL8331 (manufactured by Momentive Performance Materials Japan LLC), whose main component is 3-aminopropyltriethoxysilane, and an ethanol solution of maleic anhydride. 4) Product name TSL8350 (manufactured by Momentive Performance Materials Japan LLC), whose main component is 3-glycidoxypropyltrimethoxysilane, 0.5 parts by weight

[0057] A silicone resin mixture was prepared by mixing 100 parts by weight of a silicone resin (A3) consisting of the above 1) to 4) with 10 parts by weight of linear alkylbenzene sulfonate sodium. A main component was prepared by adding 29 parts by weight of the above silicone resin mixture and 1 part by weight of dioctyl dilaurate to 66 parts by weight of purified water. Furthermore, 5 parts by weight of the carbodiimide compound used in Example 1 (B: a mixture of a polyvalent carbodiimide compound and water) was added to 100 parts by weight of the main component mentioned above, and the mixture was stirred to prepare the coating solution. Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 5.

[0058] (Example 6) As the carbodiimide compound, the following carbodiimide compound, different from that used in Example 1, was used. C: Carbodiimide compound Aqueous solution of polyvalent carbodiimide [Polyvalent carbodiimide compound content 40% by weight, product name Carbodilite V-02-L2L, manufactured by Nisshinbo Chemical Co., Ltd., pH 8-11, viscosity (typical value) 70 mPa·s, NCN equivalent (chemical formula weight per 1 mol of carbodiimide group) 385, aqueous solution of hydrophilic group-modified polycarbodiimide compound] Then, a coating solution was prepared in the same manner as in Example 1, except that 5 parts by weight of the above-mentioned (C: mixture of polyvalent carbodiimide compound and water) was added to 100 parts by weight of the main component in Example 1, and the mixture was stirred to prepare the coating solution.

[0059] Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 6.

[0060] (Example 7) As the carbodiimide compound, the following carbodiimide compound, different from those used in Examples 1 and 6, was used. D: Carbodiimide compound Aqueous emulsion of polyvalent carbodiimide [Polyvalent carbodiimide compound content 41.3% by weight, product name Carbodilite E-05, manufactured by Nisshinbo Chemical Co., Ltd., pH 8-11, viscosity (typical value) 100 mPa·s, NCN equivalent (chemical formula weight per 1 mol of carbodiimide group) 310, aqueous emulsion of hydrophilic group-modified polycarbodiimide compound] Then, the coating solution was prepared in the same manner as in Example 1, except that 5 parts by weight of the above-mentioned (D: mixture of polyvalent carbodiimide compound and water) was added to 100 parts by weight of the main component in Example 1, and the mixture was stirred and mixed to prepare the coating solution.

[0061] Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Example 7.

[0062] (Comparative Example 1) A silicone resin mixture (A) was prepared by mixing 100 parts by weight of the silicone resin (A1) from Example 1 with 10 parts by weight of linear alkylbenzene sulfonate sodium. A coating solution was prepared by adding 29 parts by weight of the silicone resin mixture (A) and 1 part by weight of dioctyl dilaurate tin to 66 parts by weight of purified water. Then, under room temperature and atmospheric pressure conditions, the gasket core member prepared as described above was heat-treated at 100°C for 15 minutes, rotated around its central axis (300 rpm), and a coating liquid of the above composition was spray-applied (0.2 mL) to the rotating side of the gasket. After that, the gasket of the present invention was produced by drying at 100°C for 15 minutes. Subsequently, the gasket was washed with purified water at 80°C or higher to remove any excess coating liquid. The average thickness of the coating layer formed on the surface of the core member was approximately 8 μm. This gasket was designated as Comparative Example 1.

[0063] (Experiment 1: Coating strength test) A plastic plate was prepared using cyclic polyolefin (product name ZEONEX: manufactured by Nippon Zeon Co., Ltd.) as the forming material. The gaskets of Examples 1-7 and Comparative Example 1 were pressed vertically against the surface of the plastic plate with the side of the gasket having the coating layer, and then slid horizontally at a speed of 100 mm / min for 90 mm with a force of 10 N. The appearance of the plastic plate was checked after the above test. In the case of gaskets of Examples 1-7, no deposits were observed on the plastic plate, as shown in Figure 6. In the case of the gasket of Comparative Example 1, deposits that appeared to be peeled-off parts of the coating layer were observed on the plastic plate, as shown in Figure 7.

[0064] (Experiment 2: Sliding resistance measurement test) For the outer casing of a 100 mL syringe, cyclic polyolefin (product name ZEONEX: manufactured by Nippon Zeon Co., Ltd.) was used as the forming material, and a syringe casing with the shape shown in Figure 5 was fabricated by injection molding. The inner diameter of the cylindrical portion of the syringe casing was 32 mm, and its length was 154 mm. In addition, polypropylene (manufactured by Nippon Polychem Co., Ltd.) was used as the forming material for the plunger, and a plunger with the shape shown in Figure 5 was fabricated by injection molding. Then, the syringe outer barrel, the gaskets from Examples 1 to 7 and Comparative Example 1, and the plunger described above were assembled to produce a syringe.

[0065] The sliding resistance of the syringe was measured using an Autograph (model name EZ-Test, manufacturer Shimadzu Corporation). Specifically, the tip of the syringe and the rear end of the plunger were fixed to the object fixing part of the Autograph, and the sliding resistance (N) was measured when the plunger was lowered 60 mm at a speed of 100 mm / min. The results are shown in Table 1.

[0066] (Table 1) Sliding resistance value (N) Example 1: 100N Example 6 110N Example 7 105N Comparative Example 1: 105N Syringes using the gaskets in Examples 1, 6, and 7, and Comparative Example 1, exhibited similar initial and maximum sliding resistance values. Furthermore, the small difference between the initial and maximum sliding resistance values ​​meant that there was virtually no risk of the liquid being dispensed in excess of the set amount when the plunger was first pressed, allowing for safe and accurate dispensing of the liquid. In addition, the sliding properties in Examples 2-5 were approximately the same as those in Examples 1, 6, and 7.

[0067] (Experiment 3: Pressure test according to the sterile syringe standard) For the outer casing of a 100 mL syringe, cyclic polyolefin (product name ZEONEX: manufactured by Nippon Zeon Co., Ltd.) was used as the forming material, and a syringe casing with the shape shown in Figure 5 was fabricated by injection molding. The inner diameter of the cylindrical portion of the syringe casing was 32 mm, and its length was 154 mm. In addition, polypropylene (manufactured by Nippon Polychem Co., Ltd.) was used as the forming material for the plunger, and a plunger with the shape shown in Figure 5 was fabricated by injection molding.

[0068] Then, the syringe outer barrel, the gaskets from Examples 1 to 7 and Comparative Example 1, and the plunger described above were assembled to produce a syringe. These are sterile plastic syringes that can be used immediately, and The pressure test specified in the sterile syringe standards (Pharmaceutical Safety Bureau Director's Notification No. 1079, December 11, 1998), which stipulates the requirements for single-use disposable items, was performed. Each gasket in Examples 1-7 and Comparative Example 1 conformed to the standards.

[0069] The syringe gasket of the present invention is a gasket formed to make liquid-tight sliding contact with the inside of the plastic outer cylinder of a syringe, and comprises a gasket body made of an elastic material and a coating layer provided at least on the portion that contacts the syringe, wherein the coating layer is made of a condensate of reactive silicone having silanol groups at both ends, and is an elastic curing coating layer mainly composed of a silicone resin having siloxane bonds derived from the silanol groups, and also contains a carbodiimide compound together with a silane coupling agent. Therefore, the gasket provides stable sliding properties without the need to apply lubricant to the sliding surface. Furthermore, the coating layer is elastic and has sufficient strength, making it highly unlikely to peel off and thus maintaining good sliding properties. [Industrial applicability]

[0070] The syringe gasket of the present invention is as follows: (1) A gasket formed to be liquid-tight and slidably in contact with the inside of the plastic outer casing of a syringe, wherein the gasket comprises a gasket body made of an elastic material and a coating layer provided at least on the portion in contact with the syringe, the coating layer being an elastic curing coating layer made of a condensate of reactive silicone having silanol groups at both ends, mainly composed of a silicone resin having siloxane bonds derived from the silanol groups, and containing a carbodiimide compound together with a silane coupling agent.

[0071] The syringe gasket of the present invention is a gasket formed to make liquid-tight sliding contact with the inside of the plastic outer cylinder of a syringe, and comprises a gasket body made of an elastic material and a coating layer provided at least on the portion that contacts the syringe, wherein the coating layer is made of a condensate of reactive silicone having silanol groups at both ends, and is an elastic curing coating layer mainly composed of a silicone resin having siloxane bonds derived from the silanol groups, and also contains a carbodiimide compound together with a silane coupling agent. Therefore, the gasket provides stable sliding properties without the need to apply lubricant to the sliding surface. Furthermore, the coating layer is elastic and has sufficient strength, making it highly unlikely to peel off and thus maintaining good sliding properties.

[0072] Furthermore, the above embodiment may also be as follows: (2) The syringe gasket according to (1) above, wherein the carbodiimide compound is a carbodiimide having two or more carbodiimide groups. (3) The syringe gasket according to (1) or (2) above, wherein the carbodiimide compound is a polycarbodiimide. (4) The syringe gasket according to any one of (1) to (3) above, wherein the silicone resin or silane coupling agent has a functional group that reacts with the carbodiimide group of the carbodiimide compound. (5) The syringe gasket according to (4) above, wherein the functional group that reacts with the carbodiimide group is at least one selected from a carboxyl group, a hydroxyl group, an amino group, an amide group, a sulfonic acid group, and a phosphate group. (6) The syringe gasket according to any one of (1) to (5) above, wherein the silane coupling agent is at least one selected from alkylalkoxysilane, phenylalkoxysilane, aminoalkylalkoxysilane, or glycidoxyalkylalkoxysilane. (7) The syringe gasket according to any one of (1) to (5) above, wherein the silane coupling agent contains an alkylalkoxysilane or a phenylalkoxysilane as a first silane coupling agent, and further contains an aminoalkylalkoxysilane or a glycidoxyalkylalkoxysilane as a second silane coupling agent. (8) The syringe gasket according to any one of (1) to (5) above, wherein the silane coupling agent contains alkylalkoxysilane or phenylalkoxysilane as a first silane coupling agent, further contains aminoalkylalkoxysilane as a second silane coupling agent, and contains glycidoxyalkylalkoxysilane as a third silane coupling agent. (9) The syringe gasket according to any one of (1) to (8) above, wherein the elastic curing coating layer is a thermosetting elastic curing coating layer. (10) The syringe gasket according to any one of (1) to (9) above, wherein the coating layer has a thickness of 1 to 30 μm.

[0073] Furthermore, the syringe of the present invention is as follows: (11) A syringe comprising a plastic outer cylinder, a gasket according to any of (1) to (10) above slidably housed within the outer cylinder, and a plunger attached to or attachable to the gasket.

[0074] Furthermore, the above embodiment may also be as follows: (12) The syringe is the syringe described in (11) above, which is filled with a drug solution.

Claims

1. A gasket formed to be liquid-tight and slidably in contact with the inside of a cyclic polyolefin outer cylinder of a syringe, the gasket comprising a gasket body made of an elastic material and a coating layer provided at least on the portion in contact with the syringe, the coating layer being an elastic curing coating layer made of a condensate of reactive silicone having silanol groups at both ends, mainly composed of a silicone resin having siloxane bonds derived from the silanol groups, and containing a carbodiimide compound together with a silane coupling agent, the silane coupling agent being A syringe gasket having a functional group that reacts with the carbodiimide group of the carbodiimide compound, wherein the carbodiimide compound is a carbodiimide having two or more carbodiimide groups, and further, the gasket having the elastic curing coating layer is characterized in that when the side surface of the gasket having the elastic curing coating layer is pressed vertically against an annular polyolefin plate and slid horizontally at a speed of 100 mm / min for 90 mm with a force of 10 N, no residue of the elastic curing coating layer is observed to adhere to it.

2. The syringe gasket according to claim 1, wherein the carbodiimide compound is polycarbodiimide.

3. The syringe gasket according to claim 1 or 2, wherein the silane coupling agent is an aminoalkylalkoxysilane.

4. The syringe gasket according to claim 1 or 2, wherein the functional group that reacts with the carbodiimide group is at least one selected from a carboxyl group, a hydroxyl group, an amino group, an amide group, a sulfonic acid group, and a phosphate group.

5. The syringe gasket according to claim 3, wherein the aminoalkylalkoxysilane is 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, or 3-phenylaminopropyltrimethoxysilane.

6. The syringe gasket according to claim 1 or 2, wherein the silane coupling agent contains an alkylalkoxysilane or a phenylalkoxysilane as a first silane coupling agent, and further contains an aminoalkylalkoxysilane as a second silane coupling agent.

7. The syringe gasket according to claim 1 or 2, wherein the silane coupling agent contains alkylalkoxysilane or phenylalkoxysilane as a first silane coupling agent, further contains aminoalkylalkoxysilane as a second silane coupling agent, and contains glycidoxyalkylalkoxysilane as a third silane coupling agent.

8. The syringe gasket according to claim 1 or 2, wherein the elastic curing coating layer is a thermosetting elastic curing coating layer.

9. The syringe gasket according to claim 1 or 2, wherein the coating layer has a thickness of 1 to 30 μm.

10. The syringe gasket according to claim 1 or 2, wherein the coating layer has a thickness of 3 to 10 μm.

11. A syringe comprising an outer cylinder made of an annular polyolefin, a gasket according to claim 1 or 2 slidably housed within the annular polyolefin outer cylinder, and a plunger attached to or attachable to the gasket.

12. The syringe according to claim 11, wherein the syringe is filled with a drug solution.

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