WO2014054535A1 - Syringe - Google Patents

Abstract

Provided is a syringe that exhibits outstanding sliding properties between the syringe and gasket, even if a lubricant is not used. This invention is a syringe comprising a syringe barrel, a plunger, and a gasket which is fitted to the tip of the plunger, and which is made to slide in close contact with the inner wall surface of the syringe barrel. At least the surface of the gasket is made from an elastic member obtained by crosslinking a crosslinkable composition containing a fluorinated elastomer (A) and fluorinated resin (B).

Description

Syringe

The present invention relates to a syringe.

The syringe includes a syringe, a plunger, and a gasket that is attached to the tip of the plunger and is slid while closely contacting the inner wall surface of the syringe, and is held in the syringe by sliding the gasket. It extrudes a chemical.

In the syringe, the inner wall surface of the syringe and the surface of the gasket slide while being in close contact with each other, so that good sliding characteristics are required between them. Moreover, in order to hold | maintain a chemical | medical solution in a syringe, favorable airtightness and liquid tightness are also requested | required.
As the gasket, an elastic body such as rubber or elastomer is used in order to improve the airtightness and liquid tightness between the syringe and the gasket. It cannot be said that the dynamic characteristics are good.
Therefore, a lubricant such as silicone oil has been applied to the syringe inner wall in order to reduce the frictional resistance between the gasket surface and the syringe inner wall and to improve the sliding characteristics.
However, in recent years, it has been pointed out that such a lubricant is mixed into a chemical solution during use, or chemically reacts with the components of the chemical solution to adversely affect the human body. There is a need for a syringe with excellent sliding properties between the inner wall surface and the surface of the gasket.

In Patent Document 1, a syringe, a plunger, and a plunger are provided for the purpose of providing a syringe that reduces adverse effects on the human body and reduces sliding resistance while maintaining airtightness and watertightness between the syringe and the gasket. In a syringe having a gasket made of a short cylindrical elastic material that is attached to the distal end of the plunger and is slid while being in close contact with the inner wall surface of the syringe, the syringe is cylindrical in the longitudinal direction inside the gasket. A hollow portion is provided, and a cylindrical tip portion of a plunger having a size smaller than that of the cylindrical hollow portion is inserted so as to leave a longitudinal gap and / or a circumferential gap in the cylindrical hollow portion. And holding the gasket at the cylindrical tip, and on the outer peripheral surface of the gasket main body corresponding to the portion closer to the midpoint side of the shaft than both ends of the cylindrical hollow. Syringe, wherein a-up is protruded in the circumferential direction is described.

Patent Document 2 discloses a column having a rotationally symmetrical shape with respect to the axis of the syringe outer cylinder, which is slidably inserted into the syringe outer cylinder for the purpose of obtaining a syringe stopper having excellent airtightness and slidability. In a syringe stopper comprising a body, the columnar body has a maximum diameter portion at a distal end portion thereof, and R of a cross section around the distal end portion is 5/100 to 10/100 mm or less, and a rear end portion of the columnar body portion A syringe plug is characterized in that the diameter is smaller than the inner diameter of the outer cylinder when inserted into the outer cylinder of the syringe and is non-contact with the outer cylinder.

JP 2000-107290 A Japanese Patent Laid-Open No. 10-236

An object of this invention is to provide the syringe which is excellent in the slidability of a syringe and a gasket, even if it does not use a lubrication agent.

The present invention is a syringe having a syringe, a plunger, and a gasket that is attached to the tip of the plunger and is slid while being in close contact with the inner wall surface of the syringe, wherein at least the surface of the gasket is A syringe comprising an elastic member obtained by crosslinking a crosslinkable composition containing a fluororubber (A) and a fluororesin (B).

The fluororesin (B) is tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, ethylene / tetrafluoroethylene copolymer, ethylene / tetrafluoroethylene / hexafluoropropylene. Copolymer, polychlorotrifluoroethylene, chlorotrifluoroethylene / tetrafluoroethylene copolymer, ethylene / chlorotrifluoroethylene copolymer, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, vinylidene fluoride / Hexafluoropropylene / tetrafluoroethylene copolymer, vinylidene fluoride / hexafluoropropylene copolymer, and at least one selected from the group consisting of polyvinyl fluoride It is preferred.

The fluororesin (B) is preferably a perfluorofluororesin.

The fluororesin (B) is preferably a tetrafluoroethylene / hexafluoropropylene copolymer.

In the syringe of the present invention, the volume ratio of the fluororesin (B) to the elastic member is preferably 0.05 to 0.45.

The fluororubber (A) is composed of vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer, tetrafluoroethylene / propylene copolymer, tetrafluoroethylene / propylene / vinylidene fluoride. Ride copolymer, ethylene / hexafluoropropylene copolymer, ethylene / hexafluoropropylene / vinylidene fluoride copolymer, ethylene / hexafluoropropylene / tetrafluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene / perfluoro Preferably, it is at least one selected from the group consisting of (alkyl vinyl ether) copolymers and vinylidene fluoride / chlorotrifluoroethylene copolymers. There.

Since the syringe of this invention has the said structure, even if it does not use a lubricant, the slidability of a syringe and a gasket is excellent.

(A) is a perspective view showing the shape of the convex portion having the elastic member 30 of the gasket surface schematically, (b) is a plane including the straight line B ₁ and the line B ₂ perpendicular to the surface of (a) a sectional view of the convex portion 31 is a sectional view taken on (c) is a plane including a surface parallel to the straight line C ₁ and the line C ₂ of the (a). It is a cross-sectional schematic diagram which shows an example of the syringe of this invention. It is a cross-sectional schematic diagram which shows an example of the syringe of this invention. It is a cross-sectional schematic diagram which shows an example of the syringe of this invention.

The syringe of the present invention is a syringe having a syringe, a plunger, and a gasket that is attached to the distal end portion of the plunger and is slid while being in close contact with the inner wall surface of the syringe, at least the surface of the gasket Is made of an elastic member obtained by crosslinking a crosslinkable composition containing fluororubber (A) and fluororesin (B).
In the syringe of the present invention, at least the surface of the gasket is composed of an elastic member obtained by crosslinking a crosslinkable composition containing fluororubber (A) and fluororesin (B). Excellent low friction due to the fluororesin (B) is exhibited, and the slidability between the syringe and the gasket is excellent without using a lubricant. Moreover, since at least the surface of the gasket is made of the elastic member, the original flexibility of the fluororubber is not impaired, and the airtightness and liquid tightness are excellent.
Each element will be described below.

The syringe of the present invention includes a syringe, a plunger, and a gasket that is attached to the tip of the plunger and is slid while being in close contact with the inner wall surface of the syringe.

The shape of the syringe is not particularly limited, and the shape of a syringe used for a general syringe can be employed.
The material of the syringe is not particularly limited, and a material for forming a syringe used for a general syringe can be employed.
Examples of the material of the syringe include glass and synthetic resin. Examples of the synthetic resin include polypropylene, polyurethane, and fluororesin.
Synthetic resin is preferably used as the syringe material because it can be incinerated, but generally syringes made of synthetic resin are not slidable.
However, since the syringe of the present invention has the above-described configuration, the slidability between the syringe and the gasket is excellent even if the syringe is formed from a synthetic resin.

The shape of the plunger is not particularly limited, and the shape of a plunger used for a general syringe can be adopted.
The material of the plunger is not particularly limited, and a material for forming a plunger used for a general syringe can be employed.

The gasket is attached to the tip of the plunger and slides while being in close contact with the inner wall surface of the syringe.

The shape of the gasket is not particularly limited, and a general known shape used for a syringe can be employed. For example, it is cylindrical. Moreover, the column shape which has the cyclic | annular lip part which protrudes in the circumferential direction of a cylinder may be sufficient.

The gasket is made of an elastic member having at least a surface obtained by crosslinking a crosslinkable composition containing fluororubber (A) and fluororesin (B).
A part of the surface of the gasket may be made of the elastic member, or the whole surface may be made of the elastic member, and at least the surface that is in close contact with the inner wall surface of the syringe is made of the elastic member. Anything is acceptable.

The gasket may be entirely made of the elastic member (for example, see FIG. 4). Moreover, a gasket consists of a base material and the said elastic member, and may have the said elastic member on the surface of a base material (for example, refer FIG. 2 and 3).

When the gasket is entirely made of the elastic member, the elastic member has the same shape as the gasket.

The base material is preferably a rubber base material made of rubber such as butyl rubber, natural rubber, isoprene rubber or styrene-butadiene rubber from the viewpoint of the airtightness, liquid tightness, etc. of the syringe. It is not necessary to be made of rubber as long as a syringe having a property and liquid tightness is obtained, and even a hard resin or the like can be used and is not particularly limited.

FIG. 2 is a schematic cross-sectional view showing an example of the syringe of the present invention. The syringe 10 a includes a syringe 11, a plunger 12, and a gasket 15 a that is attached to the distal end portion of the plunger 12 and is slid while being in close contact with the inner wall surface of the syringe 11. The gasket 15a includes a base material 13a and a sheet-like elastic member 14a provided on the surface of the base material 13a.
In use of the syringe, the inner wall surface of the syringe 11 and the surface of the gasket 15a are slid while being in close contact with each other. However, in the syringe of the present invention, the surface of the gasket 15a is made of fluororubber (A) and fluororesin (B). By being made of the elastic member 14a obtained by crosslinking a crosslinkable composition containing, the slidability between the syringe 11 and the gasket 15a is excellent without using a lubricant.

FIG. 3 is a schematic cross-sectional view showing an example of the syringe of the present invention. The syringe 10 b includes a syringe 11 made of a synthetic resin such as polypropylene, a plunger 12, and a gasket 15 b that is attached to the distal end portion of the plunger 12 and is slid while being in close contact with the inner wall surface of the syringe 11. The gasket 15b includes a base material 13b and a sheet-like elastic member 14b provided on the surface of the base material 13b. The gasket 15b has an annular lip portion 16b that protrudes in the circumferential direction of the gasket.
The syringe of the present invention is obtained by crosslinking the crosslinkable composition containing the fluororubber (A) and the fluororesin (B) on the surface (lip portion 16b) of the gasket 15b that is in close contact with the syringe 11 and slides. By being made of the elastic member 14b, the slidability between the syringe 11 and the gasket 15b is excellent.

FIG. 4 is a schematic cross-sectional view showing an example of the syringe of the present invention. The syringe 10 c includes a syringe 11, a plunger 12, and a gasket 15 c that is attached to the distal end portion of the plunger 12 and slides while closely contacting the inner wall surface of the syringe 11. The gasket 15c is made of a cylindrical elastic member obtained by cross-linking a cross-linkable composition containing the fluoro rubber (A) and the fluoro resin (B) as a whole. The gasket 15c has a lip portion 16c that protrudes in the circumferential direction of the elastic member.
The syringe of the present invention is made of an elastic member obtained by crosslinking a crosslinkable composition containing a fluororubber (A) and a fluororesin (B), with the lip portion 16c that is in close contact with the syringe 11 and slid. Therefore, the slidability between the syringe 11 and the gasket 15c is excellent.

(A) Fluoro rubber Fluoro rubber (A) usually comprises an amorphous polymer having fluorine atoms bonded to carbon atoms constituting the main chain and having rubber elasticity. The fluororubber (A) may be composed of one kind of polymer, or may be composed of two or more kinds of polymers.

The fluororubber (A) is composed of vinylidene fluoride (VdF) / hexafluoropropylene (HFP) copolymer, VdF / HFP / tetrafluoroethylene (TFE) copolymer, TFE / propylene copolymer, TFE / propylene / VdF. Copolymer, ethylene / HFP copolymer, ethylene / HFP / VdF copolymer, ethylene / HFP / TFE copolymer, VdF / TFE / perfluoro (alkyl vinyl ether) (PAVE) copolymer, and VdF / It is preferably at least one selected from the group consisting of chlorotrifluoroethylene (CTFE) copolymers. Among these, fluororubber made of a copolymer containing VdF units is more preferable.

The fluororubber (hereinafter also referred to as “VdF-based fluororubber”) made of a copolymer containing the vinylidene fluoride (VdF) unit will be described. The VdF-based fluororubber is a fluororubber containing at least polymerized units derived from vinylidene fluoride.

The copolymer containing a VdF unit is preferably a copolymer containing a VdF unit and a copolymer unit derived from a fluorine-containing ethylenic monomer (excluding the VdF unit). The copolymer containing a VdF unit preferably further contains a copolymer unit derived from a monomer copolymerizable with VdF and a fluorine-containing ethylenic monomer.

The copolymer containing VdF units preferably contains 30 to 90 mol% of VdF units and 70 to 10 mol% of copolymerized units derived from a fluorine-containing ethylenic monomer, and 30 to 85 mol% of VdF units. More preferably, it contains 30 to 15 mol% of a copolymerized unit derived from a fluorine-containing ethylenic monomer, and 30 to 80 mol% of a VdF unit and 70 to 20 mol% of a fluorine-containing ethylenic monomer. More preferably, it contains a copolymer unit of The copolymerized unit derived from the monomer copolymerizable with VdF and the fluorine-containing ethylenic monomer is 0 to 10 mol based on the total amount of the VdF unit and the copolymerized unit derived from the fluorine-containing ethylenic monomer. % Is preferred.

Examples of the fluorine-containing ethylenic monomer include TFE, CTFE, trifluoroethylene, HFP, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, perfluoro (alkyl vinyl ether) (hereinafter, PAVE), vinyl fluoride, the following general formula (1):
CFX = CXOCF ₂ OR ¹ (1)
Wherein X is the same or different and represents H, F or CF ₃ , and R ¹ represents at least one atom selected from the group consisting of H, Cl, Br and I, which is linear or branched. A fluoroalkyl group having 1 to 6 carbon atoms which may contain 1 to 2 carbon atoms, or 1 to 2 atoms selected from the group consisting of H, Cl, Br and I And a fluorine-containing monomer such as a fluorovinyl ether represented by (C) represents a cyclic fluoroalkyl group having 5 or 6 carbon atoms. Among these, at least one selected from the group consisting of fluorovinyl ether represented by formula (1), TFE, HFP and PAVE is preferable, and at least selected from the group consisting of TFE, HFP and PAVE One type is more preferable.

As the PAVE, the general formula (2):
^{_{CF 2 = CFO (CF 2 CFY}} 1 O) p - (CF 2 CF 2 CF 2 O) q -Rf (2)
(Wherein Y ¹ represents F or CF ₃ , Rf represents a perfluoroalkyl group having 1 to 5 carbon atoms, p represents an integer of 0 to 5, and q represents an integer of 0 to 5) It is preferable that

The PAVE is preferably perfluoro (methyl vinyl ether) or perfluoro (propyl vinyl ether), and more preferably perfluoro (methyl vinyl ether). These can be used alone or in any combination.

Examples of the monomer copolymerizable with VdF and the fluorine-containing ethylenic monomer include ethylene, propylene, alkyl vinyl ether and the like.

Specific examples of such a copolymer containing VdF units include a VdF / HFP copolymer, a VdF / HFP / TFE copolymer, a VdF / CTFE copolymer, a VdF / CTFE / TFE copolymer, and a VdF. / PAVE copolymer, VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer, and at least one copolymer selected from the group consisting of VdF / HFP / TFE / PAVE copolymer Is preferred. Among these copolymers containing VdF units, at least one selected from the group consisting of VdF / HFP copolymers and VdF / HFP / TFE copolymers from the viewpoint of heat resistance and chemical resistance. The copolymer is particularly preferred. It is preferable that the copolymer containing these VdF units satisfies the composition ratio of the above-described VdF units and copolymer units derived from a fluorine-containing ethylenic monomer.

The VdF / HFP copolymer preferably has a VdF / HFP molar ratio of 45 to 85/55 to 15, more preferably 50 to 80/50 to 20, and still more preferably 60 to 80/40. ~ 20.

The VdF / HFP / TFE copolymer preferably has a VdF / HFP / TFE molar ratio of 40 to 80/10 to 35/10 to 35.

The VdF / PAVE copolymer preferably has a VdF / PAVE molar ratio of 65 to 90/10 to 35.

The VdF / TFE / PAVE copolymer preferably has a VdF / TFE / PAVE molar ratio of 40 to 80/3 to 40/15 to 35.

The VdF / HFP / PAVE copolymer preferably has a VdF / HFP / PAVE molar ratio of 65 to 90/3 to 25/3 to 25.

The VdF / HFP / TFE / PAVE copolymer preferably has a VdF / HFP / TFE / PAVE molar ratio of 40 to 90/0 to 25/0 to 40/3 to 35, more preferably 40 to 80. / 3 to 25/3 to 40/3 to 25.

The fluororubber (A) is also preferably made of a copolymer containing a copolymer unit derived from a monomer that provides a crosslinking site. Examples of the monomer that gives a crosslinking site include perfluoro (6,6-dihydro-6-iodo-3-oxa-1-) described in JP-B-5-63482 and JP-A-7-316234. Hexene) and perfluoro (5-iodo-3-oxa-1-pentene) -containing monomers, bromine-containing monomers described in JP-A-4-505341, JP-A-4-505345, Examples include cyano group-containing monomers, carboxyl group-containing monomers, and alkoxycarbonyl group-containing monomers as described in JP-T-5-500070.

The fluororubber (A) is also preferably a fluororubber having an iodine atom or a bromine atom at the end of the main chain. Fluororubber having iodine atom or bromine atom at the main chain end is produced by adding a radical initiator in the presence of a halogen compound in an aqueous medium in the absence of oxygen and performing emulsion polymerization of the monomer. it can. Representative examples of the halogen compound used include, for example, the general formula:
R ² I _x Br _y
(Wherein x and y are each an integer of 0 to 2 and satisfy 1 ≦ x + y ≦ 2, and R ² is a saturated or unsaturated fluorohydrocarbon group having 1 to 16 carbon atoms, carbon A saturated or unsaturated chlorofluorohydrocarbon group having 1 to 16 carbon atoms, or a hydrocarbon group having 1 to 3 carbon atoms, which may contain an oxygen atom).

Examples of the halogen compound include 1,3-diiodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4- Dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2 - diiodoethane, 1,3-diiodo -n- _{propane, CF 2 Br 2, BrCF 2} CF 2 Br, CF 3 CFBrCF 2 Br, CFClBr 2, BrCF 2 CFClBr, CFBrClCFClBr, BrCF 2 CF 2 CF 2 Br, BrCF 2 CFBrOCF _3, 1-bromo-2-yaw Perfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluorobutene-1, 2-bromo-4-iodoperfluorobutene-1, benzene monoiodomonobromo-substituted, diiodomonobromo-substituted, (2-iodoethyl) and (2-bromoethyl) -substituted, etc. These compounds may be used alone or in combination with each other.

Among these, it is preferable to use 1,4-diiodoperfluorobutane or diiodomethane from the viewpoints of polymerization reactivity, crosslinking reactivity, availability, and the like.

The fluororubber (A) has a Mooney viscosity (ML _{1 + 10} (100 ° C.)) of preferably 5 to 140, more preferably 10 to 120, and more preferably 20 to 100 from the viewpoint of good processability. More preferably.
Mooney viscosity can be measured according to ASTM-D1646.
Measuring equipment: ALPHA2000 TECHNOLOGIES MV2000E rotor speed: 2 rpm
Measurement temperature: 100 ° C

As the crosslinking system of the fluororubber (A), for example, at least one selected from the group consisting of a peroxide crosslinking system and a polyol crosslinking system is preferable.
From the viewpoint of chemical resistance, a peroxide crosslinking system is preferred, and from the viewpoint of heat resistance, a polyol crosslinking system is preferred. The crosslinkable composition may contain a crosslinking agent used in each crosslinking system. The amount of the crosslinking agent may be appropriately selected depending on the type of the crosslinking agent and the like, but is preferably 0.2 to 5.0 parts by mass, more preferably 0 to 100 parts by mass of the fluororubber (A). .3 to 3.0 parts by mass.

Peroxide crosslinking can be performed by using a peroxide-crosslinkable fluororubber and an organic peroxide as a crosslinking agent.

The fluororubber capable of peroxide crosslinking is not particularly limited as long as it is a fluororubber having a site capable of peroxide crosslinking. The peroxide-crosslinkable site is not particularly limited, and examples thereof include an iodine atom and a bromine atom.

The organic peroxide may be an organic peroxide that can easily generate a peroxy radical in the presence of heat or a redox system. For example, 1,1-bis (t-butylperoxy) -3, 5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α-bis (t- Butylperoxy) -p-diisopropylbenzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne -3, benzoyl peroxide, t-butyl peroxybenzene, t-butyl peroxymaleic acid, t-butyl peroxyisopropyl carbonate, t -Butyl peroxybenzoate can be mentioned. Among these, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di (t-butylperoxy) -hexyne-3 are preferable.
The compounding amount of the organic peroxide is preferably 0.1 to 15 parts by mass, more preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the fluororubber (A).

When the crosslinking agent is an organic peroxide, the crosslinking composition preferably contains a crosslinking aid. Examples of the crosslinking aid include triallyl cyanurate, triallyl isocyanurate (TAIC), triacryl formal, triallyl trimellitate, N, N′-m-phenylene bismaleimide, dipropargyl terephthalate, diallyl phthalate, Tetraallyl terephthalate amide, triallyl phosphate, bismaleimide, fluorinated triallyl isocyanurate (1,3,5-tris (2,3,3-trifluoro-2-propenyl) -1,3,5-triazine-2 , 4,6-trione), tris (diallylamine) -S-triazine, triallyl phosphite, N, N-diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallylphosphoramide, N, N, N ′ , N′-tetraallylphthalamide, N, N, ', N'- tetraallyl malonamide, trivinyl isocyanurate, 2,4,6-vinyl methyl trisiloxane, tri (5-norbornene-2-methylene) cyanurate, triallyl phosphite. Among these, triallyl isocyanurate (TAIC) is preferable in terms of excellent crosslinkability, mechanical properties, airtightness, and liquid tightness.

The amount of the crosslinking aid is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 7.0 parts by mass, and still more preferably 100 parts by mass of the fluororubber (A). Is 0.1 to 5.0 parts by mass. When the crosslinking aid is less than 0.01 parts by mass, the mechanical properties are deteriorated, and the airtightness and liquid tightness are inferior. When it exceeds 10 parts by mass, the heat resistance is inferior and the chemical resistance tends to be reduced. .

Polyol crosslinking can be performed by using a polyol-crosslinkable fluororubber and a polyhydroxy compound as a crosslinking agent.

The polyol-crosslinkable fluororubber is not particularly limited as long as it is a fluororubber having a polyol-crosslinkable site. The polyol-crosslinkable site is not particularly limited, and examples thereof include a site having a vinylidene fluoride (VdF) unit. Examples of the method for introducing the crosslinking site include a method of copolymerizing a monomer that gives a crosslinking site during the polymerization of the fluororubber.

As the polyhydroxy compound, a polyhydroxy aromatic compound is preferably used from the viewpoint of excellent heat resistance.

The polyhydroxy aromatic compound is not particularly limited. For example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), 2,2-bis (4-hydroxyphenyl) perfluoropropane (Hereinafter referred to as bisphenol AF), resorcin, 1,3-dihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4′-dihydroxydiphenyl, 4,4 ′ -Dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis (4-hydroxyphenyl) butane (hereinafter referred to as bisphenol B), 4,4-bis (4-hydroxyphenyl) valeric acid, , 2-Bis (4-hydroxyphenyl) Tetrafluorodichloropropane, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenyl ketone, tri (4-hydroxyphenyl) methane, 3,3 ′, 5,5′-tetrachlorobisphenol A, 3,3 Examples include ', 5,5'-tetrabromobisphenol A. These polyhydroxy aromatic compounds may be an alkali metal salt, an alkaline earth metal salt or the like, but when the copolymer is coagulated using an acid, it is preferable not to use the metal salt. The compounding amount of the polyhydroxy aromatic compound is 0.1 to 15 parts by mass, preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the fluororubber (A).

When the crosslinking agent is a polyhydroxy compound, the crosslinkable composition preferably contains a crosslinking accelerator. A crosslinking accelerator accelerates | stimulates the production | generation of the intramolecular double bond in the dehydrofluorination reaction of a polymer principal chain, and the addition of the polyhydroxy compound to the produced | generated double bond.

Examples of the crosslinking accelerator include onium compounds. Among onium compounds, ammonium compounds such as quaternary ammonium salts, phosphonium compounds such as quaternary phosphonium salts, oxonium compounds, sulfonium compounds, cyclic amines, and 1 It is preferably at least one selected from the group consisting of functional amine compounds, and more preferably at least one selected from the group consisting of quaternary ammonium salts and quaternary phosphonium salts.

The quaternary ammonium salt is not particularly limited. For example, 8-methyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8-methyl-1,8-diazabicyclo [5. 4.0] -7-undecenium iodide, 8-methyl-1,8-diazabicyclo [5.4.0] -7-undecenium hydroxide, 8-methyl-1,8-diazabicyclo [5] 4.0] -7-undecenium methyl sulfate, 8-ethyl-1,8-diazabicyclo [5.4.0] -7-undecenium bromide, 8-propyl-1,8-diazabicyclo [5 4.0] -7-undecenium bromide, 8-dodecyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8-dodecyl-1,8-diazabicyclo 5.4.0] -7-undecenium hydroxide, 8-eicosyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8-tetracosyl-1,8-diazabicyclo [ 5.4.0] -7-undecenium chloride, 8-benzyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride (hereinafter referred to as DBU-B), 8-benzyl -1,8-diazabicyclo [5.4.0] -7-undecenium hydroxide, 8-phenethyl-1,8-diazabicyclo [5.4.0] -7-undecenium chloride, 8- ( 3-phenylpropyl) -1,8-diazabicyclo [5.4.0] -7-undecenium chloride. Among these, DBU-B is preferable from the viewpoints of crosslinkability, mechanical properties, airtightness, and liquid tightness.

The quaternary phosphonium salt is not particularly limited. For example, tetrabutylphosphonium chloride, benzyltriphenylphosphonium chloride (hereinafter referred to as BTPPC), benzyltributylphosphonium chloride, benzyltributylphosphonium chloride, tributylallylphosphonium chloride, tributyl. -2-Methoxypropylphosphonium chloride, benzylphenyl (dimethylamino) phosphonium chloride, and the like. Among these, benzyltriphenylphosphonium chloride is used in terms of crosslinkability, mechanical properties, airtightness, and liquid tightness. (BTPPC) is preferred.

Further, as a crosslinking accelerator, a quaternary ammonium salt or a quaternary phosphonium salt and a bisphenol AF solid solution, or a chlorine-free crosslinking accelerator disclosed in JP-A-11-147891 can be used.

The blending amount of the crosslinking accelerator is preferably 0.01 to 8 parts by mass, more preferably 0.02 to 5 parts by mass with respect to 100 parts by mass of the fluororubber (A). When the crosslinking accelerator is less than 0.01 parts by mass, the crosslinking of the fluororubber does not proceed sufficiently, and the heat resistance of the resulting syringe may be lowered. If the amount exceeds 8 parts by mass, the moldability of the crosslinkable composition may decrease, the elongation in mechanical properties may decrease, and the airtightness and liquid tightness tend to decrease.

(B) Fluororesin The fluororesin (B) is preferably a melt processable fluororesin. By using a melt-processable fluororesin, the syringe of the present invention has excellent sliding characteristics between the syringe and the gasket. Moreover, the gasket which consists of an elastic member which has a convex part on the surface which is mentioned later can be obtained, and the syringe comprised from such a gasket is provided with the more excellent slidability.
Examples of the melt processable fluororesin include TFE / HFP copolymer, TFE / PAVE copolymer [PFA], Et / TFE copolymer, Et / TFE / HFP copolymer, polychlorotrifluoroethylene [ PCTFE], CTFE / TFE copolymer, Et / CTFE copolymer, polyvinylidene fluoride [PVdF], TFE / VdF copolymer, VdF / HFP / TFE copolymer, VdF / HFP copolymer, and polyfluoride. It is preferably at least one selected from the group consisting of vinyl fluoride [PVF]. Also, low molecular weight PTFE can be used as long as it is melt processable.

The fluororesin (B) is preferably a perfluorofluororesin from the viewpoint of excellent slidability between the syringe and the gasket, heat resistance, and chemical resistance.

The fluororesin (B) is a TFE / HFP copolymer, that is, a copolymer composed of TFE units and HFP units (hereinafter also referred to as “FEP”) from the viewpoint of excellent slidability between the syringe and the gasket. More preferably. FEP is also preferable in that it has excellent heat resistance.

The FEP is preferably a copolymer comprising 70 to 99 mol% of TFE units and 1 to 30 mol% of HFP units, and a copolymer comprising 80 to 97 mol% of TFE units and 3 to 20 mol% of HFP units. It is more preferable that If the TFE unit is less than 70 mol%, the mechanical properties tend to decrease, and if it exceeds 99 mol%, the melting point becomes too high and the moldability tends to decrease.

FEP may be a copolymer comprising TFE, HFP, and a monomer copolymerizable with TFE and HFP. As the monomer, CF ₂ = CF-ORf ⁶ (wherein Rf ⁶ represents a perfluoroalkyl group having 1 to 5 carbon atoms.) Perfluoro (alkyl vinyl ether) [PAVE], CX ⁵ X ⁶ = CX ⁷ (CF ₂ ) _n X ⁸ (wherein X ⁵ , X ⁶ and X ⁷ are the same or different and each represents a hydrogen atom or a fluorine atom, X ⁸ represents a hydrogen atom, a fluorine atom or a chlorine atom, and n represents an integer of 2 to 10. A vinyl monomer, and an alkyl perfluorovinyl ether derivative represented by CF ₂ ═CF—OCH ₂ —Rf ⁷ (wherein Rf ⁷ represents a perfluoroalkyl group having 1 to 5 carbon atoms). Named, Even if, it is preferable that the PAVE.

The PAVE is selected from the group consisting of perfluoro (methyl vinyl ether) [PMVE], perfluoro (ethyl vinyl ether) [PEVE], perfluoro (propyl vinyl ether) [PPVE], and perfluoro (butyl vinyl ether). It is preferably at least one, and more preferably at least one selected from the group consisting of PMVE, PEVE and PPVE.

As the alkyl perfluorovinyl ether derivative, those in which Rf ⁷ is a perfluoroalkyl group having 1 to 3 carbon atoms are preferable, and CF ₂ ═CF—OCH ₂ —CF ₂ CF ₃ is more preferable.

In FEP, the monomer units derived from monomers copolymerizable with TFE and HFP are 0.1 to 10 mol%, and the total of TFE units and HFP units is 90 to 99.9 mol%. Is preferred. If the copolymerizable monomer unit is less than 0.1 mol%, the moldability, environmental stress crack resistance and stress crack resistance tend to be inferior, and if it exceeds 10 mol%, heat resistance, mechanical properties, and productivity are obtained. Tend to be inferior.

The melting point of the fluororesin (B) is preferably equal to or higher than the primary crosslinking temperature of the fluororubber (A). Although melting | fusing point of a fluororesin (B) is suitably determined by the kind of fluororubber (A), it is more preferable that it is 150 degreeC or more, and it is still more preferable that it is 180 degreeC or more. Although an upper limit is not specifically limited, For example, it may be 300 degreeC.
If the melting point is too low, the fluororesin melts at the time of cross-linking molding described later, and a cross-linked molded product having a desired shape may not be obtained. Moreover, when forming the convex part which is mentioned later on the surface of an elastic member, there exists a possibility that the elastic member which has a sufficient number of convex parts may not be obtained.

The fluororesin (B) preferably has a melt flow rate [MFR] at 372 ° C. of 0.3 to 100 g / 10 min. If the MFR is too small, good slidability may not be obtained, and if the MFR is too large, molding may be difficult.
The MFR is a value obtained by measuring at a temperature of 372 ° C. and a load of 5 kg in accordance with ASTM-D1238.

In order to improve the compatibility between the fluororesin (B) and the fluororubber (A), the crosslinkable composition may contain at least one polyfunctional compound. The polyfunctional compound is a compound having two or more functional groups having the same or different structures in one molecule.

The functional groups possessed by the polyfunctional compound include carbonyl groups, carboxyl groups, haloformyl groups, amide groups, olefin groups, amino groups, isocyanate groups, hydroxy groups, epoxy groups, etc., which are generally known to have reactivity. Any group can be used.
The compounds having these functional groups not only have high affinity with the fluororubber (A), but also react with functional groups known to have the reactivity possessed by the fluororesin (B), and are further compatible with each other. Is expected to improve.

The crosslinkable composition containing the fluororubber (A) and the fluororesin (B) has a volume ratio of the fluororubber (A) to the fluororesin (B) (fluororubber (A)) / (fluororesin (B)). Is preferably 60/40 to 95/5. If the amount of the fluororesin (B) is too small, the slidability between the syringe and the gasket may be insufficient. On the other hand, if the amount of the fluororesin (B) is too large, the rubber elasticity of the gasket surface may be impaired. From the point that both the flexibility (airtightness and liquid-tightness of the syringe) due to the fluororubber and the low friction (slidability between the syringe and the gasket) due to the fluororesin are good, (the fluororubber (A )) / (Fluororesin (B)) is more preferably 65/35 to 95/5, and still more preferably 70/30 to 90/10.

The above-mentioned crosslinkable composition is a usual additive blended in the fluororubber as necessary, for example, a filler, a processing aid, a plasticizer, a colorant, a stabilizer, an adhesion aid, a mold release agent, a conductivity. Various additives such as an imparting agent, a thermal conductivity imparting agent, a surface non-adhesive agent, a flexibility imparting agent, a heat resistance improving agent, and a flame retardant can be blended, and these additives impair the effects of the present invention. It may be used within the range.

The elastic member is obtained by crosslinking a crosslinkable composition containing fluororubber (A) and fluororesin (B). The elastic member is not limited as long as it is obtained by crosslinking a crosslinkable composition containing fluororubber (A) and fluororesin (B), but is preferably obtained by a production method described later. .

The elastic member preferably has a convex portion on the surface. Since the convex portion exists on the surface of the elastic member, the syringe of the present invention is excellent in the sliding property between the syringe and the gasket.

It is preferable that a convex part consists of a fluororesin (B) substantially contained in a crosslinkable composition. A convex part can be formed by depositing the fluororesin (B) contained in the said crosslinkable composition on the surface by the method mentioned later, for example.

The convex part does not have a clear interface or the like between the elastic member, and the convex part and the elastic member are integrally formed, and the convex part is unlikely to drop off or be lost.

The fact that the convex portion is substantially made of the fluororesin (B) contained in the crosslinkable composition means that the peak ratio between the peak derived from the fluororubber (A) and the peak derived from the fluororesin (B) by IR analysis or ESCA analysis. It can be shown by seeking. For example, in a region having a convex portion, by IR analysis, a ratio (a component-derived peak ratio) between a characteristic absorption peak derived from the fluororubber (A) and a characteristic absorption peak derived from the fluororesin (B) is calculated as It is measured at each part outside the convex part, and (the convex part peak / outside convex part peak = peak ratio) may be 1.2 or more, preferably 1.5 or more.

The shape of the protrusion will be described in more detail with reference to the drawings.
FIG. 1A is a perspective view schematically showing the shape of the convex portion of the elastic member 30 on the gasket surface, and FIG. 1B includes straight lines B ₁ and B ₂ perpendicular to the surface of FIG. a sectional view of the convex portion 31 in plan, is a cross-sectional view taken along (c) is a plane including a surface parallel to the straight line C ₁ and the line C ₂ of the (a). 1 (a) to 1 (c) schematically depict a minute region on the surface of the syringe. As shown in FIGS. 1A to 1C, for example, a substantially conical (cone-shaped) convex portion 31 is formed on the surface of the syringe.

Here, the height of the convex portion 31 refers to the height of the portion protruding from the surface of the elastic member (see H in FIG. 1B). Further, the bottom cross-sectional area of the projecting portion 31, the convex portion 31 convex portion 31 is observed in the cut surface of an elastic member parallel to the surface plane (a plane including the straight line C ₁ and the line C ₂₎ (Figure 1 (C) refers to the value of the area in the cross section.

It is preferable that the area ratio of the region having the convex portion (occupation ratio of the convex portion) is 0.06 (6%) or more with respect to the surface area of the elastic member. A more preferable area ratio is 0.15 (15%) or more, and further preferably 0.30 (30%) or more. The area ratio of the region having the convex portion on the surface of the elastic member refers to the ratio of the area occupied by the convex portion in the cut surface for evaluating the bottom cross-sectional area of the convex portion.

In the elastic member, the volume ratio of the fluororesin (B) is preferably 0.05 to 0.45 (5 to 45% by volume) with respect to the elastic member. The lower limit of the volume ratio is more preferably 0.10 (10% by volume). The upper limit of the volume ratio is more preferably 0.40 (40% by volume), still more preferably 0.35 (35% by volume), and particularly preferably 0.30 (30% by volume). . Since the fluororesin has excellent heat resistance, it is not decomposed by the molding cross-linking step or the heat treatment step, so it can be assumed that the volume ratio is the same as the volume ratio of the fluororesin in the cross-linkable composition.

The area ratio of the region having the convex portions is preferably 1.2 times or more, more preferably 1.3 times or more of the volume ratio of the fluororesin (B). The ratio of the area | region which has a convex part in the surface of an elastic member is higher than the volume ratio of the fluororesin (B) of an elastic member, and the said elastic member becomes higher than the volume ratio of the fluororesin in a crosslinkable composition.
Due to this feature, even if the mixing ratio of the fluororesin is small, the elastic member improves the slidability, which was a drawback of the fluororubber, and does not impair the advantages of the fluororubber.
In addition, if the area ratio of the area | region which has the said convex part is achieved in the surface part of the gasket closely_contact | adhered with a syringe, the effect of this invention will be fully show | played.

The convex portion preferably has a height of 0.1 to 30.0 μm. When the height of the convex portion is within this range, the slidability between the syringe and the gasket is more excellent. The height is more preferably 0.3 to 20.0 μm, still more preferably 0.5 to 10.0 μm.

The convex part preferably has a bottom sectional area of 0.1 to 2000 μm ² . When the bottom cross-sectional area of the convex portion is within this range, the slidability between the syringe and the gasket is more excellent. A more preferable bottom cross-sectional area is 0.3 to 1500 μm ² , and a still more preferable bottom cross-sectional area is 0.5 to 1000 μm ² .

The elastic member preferably has a standard deviation of the height of the convex portion of 0.300 or less. Within this range, the slidability between the syringe and the gasket is more excellent.

The elastic member preferably has 500 to 60000 convex portions / mm ² . Within this range, the slidability between the syringe and the gasket is more excellent.

The area ratio, the height of the convex portion, the sectional area of the bottom portion of the convex portion, the number of convex portions, etc., for example, manufactured by Keyence Corporation, using a color 3D laser microscope (VK-9700) as analysis software WinRooF Ver. It can be calculated using 6.4.0. The area ratio of the region having the convex part is obtained as the ratio of the total cross-sectional area to the total cross-sectional area value obtained by calculating the bottom cross-sectional area of the convex part. The number of convex portions is obtained by converting the number of convex portions in the measurement region into a number per 1 mm ² .

In the elastic member, the convex portion may be formed on a part of the surface of the elastic member, and the elastic member may have a region where the convex portion is not formed. For example, the convex portion need not be formed in a portion that is not in close contact with the syringe.

Next, the manufacturing method of the syringe of this invention is demonstrated.

The syringe of the present invention is preferably obtained by the following production method. By the following manufacturing method, it is possible to manufacture a syringe including a base material and the above elastic member, and having a gasket provided with the above elastic member on the surface of the base material.
The syringe of the present invention is
A mixing step of mixing the fluororubber (A) and the fluororesin (B) to obtain a crosslinkable composition;
A molding and crosslinking step for obtaining a crosslinked molded article having a desired shape by molding and crosslinking the crosslinkable composition;
A heat treatment step for obtaining an elastic member by heating the cross-linked molded article obtained in the molding cross-linking step to a temperature equal to or higher than the melting point of the fluororesin (B)
Providing an elastic member on the surface of the substrate to obtain a gasket having at least a surface made of the elastic member; and
Attaching the obtained gasket to the tip of the plunger and inserting the plunger with the gasket into the syringe;
It is preferable to be obtained by a production method comprising (hereinafter referred to as “first production method”).
Each step will be described below.

[Mixing process]
The method for obtaining the crosslinkable composition is not particularly limited as long as a method capable of uniformly mixing the fluororubber (A) and the fluororesin (B) is used. For example, the fluororubber (A) and the fluororesin (B) And a method of co-coagulating the fluororubber (A) and the fluororesin (B) are preferable.
Below, melt-kneading and co-coagulation will be described.

(Melt kneading)
The melt-kneading is performed with the fluororubber (A) and the fluororesin (B) at a temperature that is at least 5 ° C. lower than the melting point of the fluororesin (B), preferably at a temperature that is higher than the melting point of the fluororesin (B). The upper limit of the heating temperature is lower than the lower thermal decomposition temperature of the fluororubber (A) or the fluororesin (B).

Melt-kneading is not performed under conditions that cause crosslinking at that temperature (in the presence of a crosslinking agent, crosslinking accelerator, and acid acceptor, etc.), but crosslinking is caused at a melt-kneading temperature that is 5 ° C lower than the melting point of the fluororesin. If there are no components (for example, only a specific cross-linking agent, only a combination of a cross-linking agent and a cross-linking accelerator, etc.), they may be added and mixed during melt kneading. Examples of conditions that cause crosslinking include a combination of a polyol crosslinking agent, a crosslinking accelerator, and an acid acceptor.

Therefore, in the above melt kneading, the fluororubber (A) and the fluororesin (B) are melt kneaded to prepare a pre-compound (preliminary mixture), and then other additives and compounding agents are added at a temperature lower than the crosslinking temperature. A two-stage kneading method in which a full compound (crosslinkable composition) is obtained by kneading is preferred. Of course, a method of kneading all the components at a temperature lower than the crosslinking temperature of the crosslinking agent may be used.

As said crosslinking agent, well-known crosslinking agents, such as an amine crosslinking agent, a polyol crosslinking agent, and a peroxide crosslinking agent, can be used.

Melt kneading is performed by kneading with fluororubber using a Banbury mixer, a pressure kneader, an extruder, etc. at a temperature of 5 ° C. lower than the melting point of the fluororesin, for example, 180 ° C. or more, usually 200 to 290 ° C. It can be carried out. Among these, it is preferable to use an extruder such as a pressure kneader or a twin screw extruder because a high shear force can be applied.

Further, full compounding in the two-stage kneading method can be performed using an open roll, a Banbury mixer, a pressure kneader, or the like at a temperature lower than the crosslinking temperature, for example, 100 ° C. or lower.

As a process similar to the above melt-kneading, there is a process (dynamic cross-linking) of cross-linking fluororubber in a fluororesin under the melt condition of the fluororesin. Dynamic crosslinking is a method in which uncrosslinked rubber is blended in a matrix of a thermoplastic resin, uncrosslinked rubber is crosslinked while kneading, and the crosslinked rubber is dispersed microscopically in the matrix. Is melt kneaded under conditions that do not cause cross-linking (such as the absence of components necessary for cross-linking or a compound that does not cause a cross-linking reaction at that temperature), and the matrix becomes uncross-linked rubber, It is essentially different in that it is a mixture in which the fluororesin is uniformly dispersed.

(Coaggregation)
From the viewpoint that the fluororubber (A) and the fluororesin (B) are more uniformly mixed, the crosslinkable composition is preferably obtained by co-coagulation. That is, the crosslinkable composition preferably contains a fluororubber (A) and a fluororesin (B) obtained by co-coagulation. By using co-coagulation, it is possible to manufacture a syringe that is more slidable between the syringe and the gasket. Moreover, the convex part formed in the surface of an elastic member can be formed uniformly, and the area ratio (occupancy) of the area | region which has a convex part can also be made high enough.

When the crosslinkable composition contains co-coagulated fluororubber (A) and fluororesin (B), the fluororubber (A) and fluororesin (B) are uniformly dispersed in the crosslinkable composition. It is expected that

Examples of the co-coagulation method include: (i) a method in which an aqueous dispersion of fluororubber (A) and an aqueous dispersion of fluororesin (B) are mixed and then coagulated; (ii) fluororubber ( A method in which the powder of A) is coagulated after being added to the aqueous dispersion of fluororesin (B), and (iii) the powder of fluororesin (B) is coagulated after being added to the aqueous dispersion of fluororubber (A). The method of analyzing is mentioned. As the co-coagulation method, the above method (i) is particularly preferable in that each resin is easily dispersed uniformly.

The coagulation in the coagulation methods (i) to (iii) can be performed using, for example, a flocculant. Such a flocculant is not particularly limited, but examples thereof include aluminum salts such as aluminum sulfate and alum, calcium salts such as calcium sulfate, magnesium salts such as magnesium sulfate and magnesium chloride, sodium chloride and potassium chloride. And known aggregating agents such as monovalent cation salts. When coagulating with a flocculant, the pH may be adjusted by adding an acid or an alkali in order to promote aggregation.

The crosslinkable composition preferably contains a co-coagulated powder obtained by co-coagulating the fluororubber (A) and the fluororesin (B). For example, the co-coagulated powder is coagulated after mixing the aqueous dispersion of fluororubber (A) and the aqueous dispersion of fluororesin (B), and then the coagulated product is recovered and dried as desired. Can be obtained. Moreover, it is preferable that the said crosslinkable composition contains the said co-coagulated powder and a crosslinking agent, and may further contain the various additives etc. which are mentioned later.
The crosslinkable composition is obtained by co-coagulating fluororubber (A) and fluororesin (B) to obtain a co-coagulated powder, and adding a cross-linking agent to the co-coagulated powder. It is preferable.

Depending on the cross-linking system of the fluororubber (A), a cross-linking agent may be necessary. Therefore, after co-coagulating the fluororubber (A) and the fluororesin (B) to obtain a co-coagulated powder, A crosslinkable composition may be obtained by adding a crosslinking agent.

Usually, after adding a cross-linking agent to the co-coagulated powder, the co-coagulated powder and the cross-linking agent are mixed. The said mixing can be mixed by the normal mixing method using a kneader etc. at the temperature below melting | fusing point of a fluororesin (B), for example.

[Molding cross-linking step]
Next, a cross-linked molded body having a desired shape is produced by molding and cross-linking the cross-linkable composition. The order of molding and crosslinking is not limited, and may be crosslinked after molding, may be molded after crosslinking, or may be molded and crosslinked simultaneously.

The molding and crosslinking methods of the crosslinkable composition may be known methods for the molding and crosslinking employed.

Examples of the molding method include extrusion molding, compression molding, injection molding, transfer molding, and the like.

As the cross-linking method, a steam cross-linking method, a pressure molding method, a radiation cross-linking method, or a normal method in which a cross-linking reaction is started by heating can be employed. In the present invention, a crosslinking reaction by heating is preferable because the sliding property between the syringe and the gasket is more excellent.

The temperature at which crosslinking is performed is not less than the crosslinking temperature of the fluororubber (A) and is preferably less than the melting point of the fluororesin (B). If the crosslinking is performed at a melting point or higher of the fluororesin (B), the fluororesin (B) melts at the time of cross-linking molding, and an elastic member having a sufficient number of convex portions cannot be obtained, and sufficient slidability is obtained. There is a risk of not being able to. More preferably, the crosslinking temperature is less than 5 ° C. lower than the melting point of the fluororesin (B) and not less than the crosslinking temperature of the fluororubber (A). The crosslinking time is, for example, 1 minute to 24 hours, and may be appropriately determined depending on the type of crosslinking agent used.

By the way, in the cross-linking of fluororubber, after the first cross-linking treatment (referred to as primary cross-linking), a post-processing step called secondary cross-linking may be performed, but as described in the heat treatment step below, The secondary crosslinking step and the heat treatment step of this specification are different treatment steps.

[Heat treatment process]
In this step, the elastic molded member is obtained by heating the crosslinked molded body obtained in the molding crosslinking step to a temperature equal to or higher than the melting point of the fluororesin (B).

The heat treatment step is a treatment step performed to increase the ratio of the fluororesin on the surface of the elastic member. In accordance with this purpose, the melting point of the fluororesin (B) and the fluororubber (A) and the fluororesin (B) A temperature lower than the thermal decomposition temperature is adopted as the heating temperature.

When heating temperature is lower than melting | fusing point of a fluororesin (B), the elastic member which has many convex parts cannot be obtained. Moreover, in order to avoid thermal decomposition of fluororubber and fluororesin, the heating temperature must be lower than the lower thermal decomposition temperature of fluororubber (A) or fluororesin (B). A preferable heating temperature is a temperature that is 5 ° C. or more higher than the melting point of the fluororesin because the slidability can be improved in a short time.

The above upper limit temperature is the case of ordinary fluoro rubber, and in the case of fluoro rubber having super heat resistance, since the upper limit temperature is the decomposition temperature of fluoro rubber having super heat resistance, the above upper limit temperature is not limited to this. .

In the heat treatment step, the heating temperature is closely related to the heating time. When the heating temperature is relatively close to the lower limit, the heating is performed for a relatively long time, and when the heating temperature is relatively close to the upper limit, the heating time is relatively short. It is preferable to adopt. As described above, the heating time may be appropriately set in relation to the heating temperature. However, if the heat treatment is performed for a long time, the fluororubber may be thermally deteriorated. It is practically up to 96 hours excluding the case where is used. Usually, the heat treatment time is preferably 1 minute to 72 hours. From the viewpoint of good productivity, 1 minute to 24 hours is more preferable, but from the viewpoint of improving slidability, 8 to 72 hours is more preferable.

By the way, the conventional secondary cross-linking completely decomposes the cross-linking agent remaining at the end of the primary cross-linking to complete the cross-linking of the fluororubber, thereby improving the mechanical properties and compression set properties of the cross-linked molded product. This is a process to be performed.
Therefore, the conventional secondary crosslinking conditions that do not assume the coexistence of the fluororesin (B) are present in the secondary crosslinking even if the crosslinking conditions accidentally overlap with the heating conditions of the heat treatment step in the present invention. Is not used as a factor for setting the crosslinking conditions, but only the heating conditions within the range of the purpose of completion of crosslinking of the fluororubber (complete decomposition of the crosslinking agent) are employed, and the fluororesin (B) is blended. In this case, the conditions for heat softening or melting the fluororesin (B) in a crosslinked rubber (not an uncrosslinked rubber) cannot be derived.

In addition, in the said shaping | molding bridge | crosslinking process, you may perform secondary bridge | crosslinking in order to complete bridge | crosslinking of fluororubber (A) (in order to decompose | disassemble a crosslinking agent completely).

Further, in the heat treatment step, the remaining crosslinking agent may be decomposed to complete the cross-linking of the fluororubber (A). However, the cross-linking of the fluororubber (A) in the heat treatment step is only a secondary effect. Absent.

By performing the heat treatment step, it is possible to obtain a syringe in which the characteristics of the fluororesin (B) are sufficiently exhibited on the surface of the elastic member and the slidability is remarkably improved as compared with those without heat treatment. In addition, the characteristics of the fluororubber (A) can be exhibited in areas other than the surface area of the elastic member, and as a whole, an excellent syringe can be obtained with a good balance in terms of slidability, airtightness, and liquidtightness between the syringe and the gasket. .

[Process for obtaining gaskets]
The step of providing the elastic member on the surface of the base material to obtain a gasket having at least the surface made of the elastic member is not particularly limited as long as the elastic member is provided on at least a portion of the gasket that is in close contact with the inner wall of the syringe. . For example, a method of winding a sheet-like elastic member around the surface of a columnar base material and bonding the base material and the elastic member can be used.
Examples of the method for bonding the base material and the elastic member include a method of bonding by co-crosslinking the base material and the elastic member, a method using an adhesive, and the like.

[Step of obtaining a syringe]
The process generally performed in manufacture of a syringe can be employ | adopted as the process of attaching the obtained gasket to the front-end | tip part of a plunger, and inserting the plunger equipped with the gasket into a syringe, and obtaining a syringe.

By the first manufacturing method, it is possible to manufacture a syringe including a base material and the elastic member, and having a gasket in which the elastic member is provided on the surface of the base material.

In the syringe of the present invention, the entire gasket may be made of an elastic member. In that case, the syringe of the present invention is preferably obtained by the following production method.
The syringe of the present invention is
A mixing step in which the fluororubber (A) and the fluororesin (B) are melt-kneaded or co-coagulated to obtain a crosslinkable composition;
A molding and crosslinking step for obtaining a crosslinked molded article having a desired shape by molding and crosslinking the crosslinkable composition;
A heat treatment step of obtaining a gasket made of an elastic member by heating the cross-linked molded product obtained in the molding cross-linking step to a temperature equal to or higher than the melting point of the fluororesin (B); and
Attaching the obtained gasket to the tip of the plunger and inserting the plunger with the gasket into the syringe;
It may be obtained by a production method comprising (hereinafter also referred to as “second production method”).
In the second production method, the molding and crosslinking step is to obtain a crosslinked molded body having substantially the same shape as the gasket, and does not require a step of providing an elastic member on the surface of the base material. The same method as the first manufacturing method can be adopted except that a gasket made of members is obtained.

Here, although the specific method for obtaining the syringe of this invention is demonstrated, the method of obtaining the syringe of this invention is not restricted to the following method.

(Synthesis Example 1)
The following fluororesin dispersion (B1) and the following fluororubber dispersion (A1) are mixed in a solution in which 500 cc of water and 4 g of magnesium chloride are mixed in advance in a mixer having a capacity of 1 L, and the solid content is 75/25 (fluorine). 400 cc of a solution previously mixed so as to be (rubber / FEP) was added, mixed for 5 minutes in a mixer, and co-coagulated.
After co-coagulation, the solid content is taken out, dried in a drying oven at 120 ° C. for 24 hours, and then mixed with the following filler, crosslinking agent, crosslinking accelerator, and crosslinking aid in the number of parts shown in Table 1. Thus, a crosslinkable composition 1 was obtained.

(Example 1)
Thereafter, the resulting crosslinkable composition 1 was molded into a gasket shape using a molding die, and crosslinked at 180 ° C. for 5 minutes at 40 kg / cm ² to obtain a crosslinked molded product.
Thereafter, the crosslinked molded product was placed in a heating furnace maintained at 230 ° C. for 24 hours and subjected to heat treatment to produce a gasket 1.
The manufactured gasket of the present invention shown in FIG. 4 can be obtained by attaching the manufactured gasket to the plunger and inserting it into the syringe.

(Synthesis Example 2)
The following fluororesin dispersion (B1) and the following fluororubber dispersion (A1) were added to a solution prepared by previously mixing 500 cc of water and 4 g of magnesium chloride in a mixer having a capacity of 1 L, and the solid content was 92.5 / 7 in volume ratio. 400 cc of a solution mixed in advance so as to be 5 (fluororubber / FEP) was added, mixed for 5 minutes in a mixer, and co-coagulated.
After co-coagulation, the solid content is taken out, dried in a drying oven at 120 ° C. for 24 hours, and then mixed with the following filler, crosslinking agent, crosslinking accelerator, and crosslinking aid in the number of parts shown in Table 1. Thus, a crosslinkable composition 2 was obtained.

(Example 2)
A gasket 2 was obtained in the same manner as in Example 1 except that the crosslinkable composition 2 was used instead of the crosslinkable composition 1.

(Synthesis Example 3)
The following fluororesin dispersion (B1) and the following fluororubber dispersion (A1) are mixed into a solution prepared by previously mixing 500 cc of water and 4 g of magnesium chloride in a mixer having a capacity of 1 L, and the solid content is 87.5 / 12 in volume ratio. 400 cc of a solution mixed in advance so as to be 5 (fluororubber / FEP) was added, mixed for 5 minutes in a mixer, and co-coagulated.
After co-coagulation, the solid content is taken out, dried in a drying oven at 120 ° C. for 24 hours, and then mixed with the following filler, crosslinking agent, crosslinking accelerator, and crosslinking aid in the number of parts shown in Table 1. Thus, a crosslinkable composition 3 was obtained.

(Example 3)
A gasket 3 was obtained in the same manner as in Example 1 except that the crosslinkable composition 3 was used instead of the crosslinkable composition 1.

(Synthesis Example 4)
The following fluororesin dispersion (B1) and the following fluororubber dispersion (A1) are mixed in a solution in which 500 cc of water and 4 g of magnesium chloride are mixed in advance in a mixer having a capacity of 1 L, and the solid content is 60/40 (fluorine in volume ratio). 400 cc of a solution previously mixed so as to be (rubber / FEP) was added, mixed for 5 minutes in a mixer, and co-coagulated.
After co-coagulation, the solid content is taken out, dried in a drying oven at 120 ° C. for 24 hours, and then mixed with the following filler, crosslinking agent, crosslinking accelerator, and crosslinking aid in the number of parts shown in Table 1. Thus, a crosslinkable composition 4 was obtained.

Example 4
A gasket 4 was obtained in the same manner as in Example 1 except that the crosslinkable composition 4 was used instead of the crosslinkable composition 1.

Fluoro rubber dispersion (A1)
Dispersion (solid content concentration: 24% by mass) of polyol-crosslinkable binary fluororubber (VdF / HFP copolymer, VdF / HFP = 78/22, Mooney viscosity (ML _{1 + 10} (100 ° C.)): 80)

Fluorine resin dispersion (B1)
Aqueous dispersion (solid content concentration: 21) of FEP (TFE / HFP copolymer, TFE / HFP = 87.9 / 12.1, MFR: 31.7 g / 10 min (measured at 327 ° C.), melting point: about 215 ° C.) mass%)

Filler: Carbon black (MT carbon manufactured by Cancarb: N990)
Cross-linking agent: Bisphenol AF Special grade reagent Wako Pure Chemical Industries, Ltd. Cross-linking accelerator: BTPPC Special grade reagent Wako Pure Chemical Industries, Ltd. Cross-linking aid: Magnesium oxide MA 150, manufactured by Kyowa Chemical Industry Co., Ltd.
CALDIC2000 manufactured by Omi Chemical Co., Ltd.

(Synthesis Example 5)
Butyl rubber (BUTYL365, manufactured by JSR Corporation) was mixed with the following filler, crosslinking agent, crosslinking accelerator, and softener in the number of parts shown in Table 2 using an open roll to obtain a crosslinkable composition 5.

(Comparative Example 1)
Thereafter, the obtained crosslinkable composition 5 was molded into a gasket shape using a molding die, and crosslinked at 160 ° C. for 20 minutes at 40 kg / cm ² to produce a gasket 5.

Filler: Carbon black (Shiest SO manufactured by Tokai Carbon Co., Ltd.)
Zinc oxide (3 types of zinc oxide manufactured by Mitsui Mining & Smelting Co., Ltd.)
Stearic acid (stearic acid “椿” manufactured by NOF Corporation)
Crosslinking agent: Sulfur MIDAON MIDAS-105
Cross-linking accelerator: Sunseller EM-5-CR Sanshin Chemical Co., Ltd. Softener: Paraffin oil (Process oil PT-32 manufactured by Idemitsu Kosan Co., Ltd.)

(Slidability measurement)
The dynamic friction coefficient was measured according to JIS K7125. The crosslinkable compositions 1 to 5 obtained in Synthesis Examples 1 to 5 were press-molded to obtain 120 mm × 160 mm × 2 mm samples (test sheets). A 94 g weight was placed on the obtained sample in a state where a molded product (65 mm × 65 mm × 3 mm, 6 g) of a cycloolefin polymer (COP, manufactured by Nippon Zeon Co., Ltd.) was brought into contact with the obtained sample. Using a universal material testing machine 5566 manufactured by Instron, the COP molded product was pulled horizontally at a sliding speed of 100 mm / min, and the average load (F) while the weight was moving was measured. Asked. The number of measurements was set for each sample n = 4. Only in the case of the test sheet obtained from the crosslinkable composition 5, a lubricating oil (silicone oil, 360 Medica Fluid, 100 cSt, manufactured by Toray Dow Corning Co., Ltd.) is applied between the mating material and measurement is performed. It was. The results are shown in Table 3.

Coefficient of dynamic friction (μ) = F (g) / Weight (weight + mating material) (g)

10a, 10b, 10c: syringe 11: syringe 12: plunger 13a, 13b: base material 14a, 14b: elastic member 15a, 15b: gasket 15c: gasket (elastic member)
16b, 16c: Lip part 30: Elastic member 31: Convex part

Claims (6)

1. A syringe having a syringe, a plunger, and a gasket that is attached to the tip of the plunger and is slid while being in close contact with the inner wall surface of the syringe,
   At least surface of the said gasket consists of an elastic member obtained by bridge | crosslinking the crosslinkable composition containing a fluororubber (A) and a fluororesin (B), The syringe characterized by the above-mentioned.
2. The fluororesin (B) is tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymer, ethylene / tetrafluoroethylene copolymer, ethylene / tetrafluoroethylene / hexafluoropropylene. Copolymer, polychlorotrifluoroethylene, chlorotrifluoroethylene / tetrafluoroethylene copolymer, ethylene / chlorotrifluoroethylene copolymer, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, vinylidene fluoride / Hexafluoropropylene / tetrafluoroethylene copolymer, vinylidene fluoride / hexafluoropropylene copolymer, and at least one selected from the group consisting of polyvinyl fluoride Syringe to claim 1, wherein.
3. The syringe according to claim 1 or 2, wherein the fluororesin (B) is a perfluorofluororesin.
4. The syringe according to claim 1, 2 or 3, wherein the fluororesin (B) is a tetrafluoroethylene / hexafluoropropylene copolymer.
5. The syringe according to claim 1, 2, 3 or 4, wherein the volume ratio of the fluororesin (B) to the elastic member is 0.05 to 0.45.
6. The fluororubber (A) is composed of vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer, tetrafluoroethylene / propylene copolymer, tetrafluoroethylene / propylene / vinylidene fluoride. Ride copolymer, ethylene / hexafluoropropylene copolymer, ethylene / hexafluoropropylene / vinylidene fluoride copolymer, ethylene / hexafluoropropylene / tetrafluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene / perfluoro The (alkyl vinyl ether) copolymer and at least one selected from the group consisting of vinylidene fluoride / chlorotrifluoroethylene copolymer, , 3, 4 or 5 syringe according.

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