JPS6355065A - Laminated rubber plug - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a laminated rubber stopper, and more particularly to a rubber stopper in which a fluorine-containing thermoplastic rubber is laminated at least at the container mouth insertion portion of the stopper body.

The laminate rubber stopper of the present invention is a rubber stopper with excellent chemical resistance, and is particularly suitable for storing pharmaceuticals in containers and maintaining the purity of pharmaceutical products for a long period of time.

Prior Art] Conventionally, materials such as glass, natural rubber, synthetic rubber, and silicone rubber have been used as materials for plugs.

However, the material for the closure of containers for storing or containing highly corrosive liquids, highly soluble or highly swellable liquids, etc. is very important, but there are no known materials that are resistant to all chemicals. Rubber is particularly stable against fuming nitric acid, concentrated nitric acid, dilute nitric acid, concentrated sulfuric acid, hydrochloric acid, phosphoric acid, alkaline solutions, amines, ammonia or hydrofluoric acid, as well as pharmaceuticals such as anticancer drugs and antibiotics. There is no stopper material.

Further, rubber stoppers for pharmaceutical use and the like are required to be gas impermeable and safe, but there are no materials that fully satisfy these requirements. Furthermore, although rubber stoppers for pharmaceutical use and the like are sterilized before use, it is also necessary that the constituent components of the rubber are not eluted by hot water treatment, which is the simplest sterilization method.

For this reason, in the case of highly corrosive liquids, use polyethylene rather than rubber.
Although synthetic resins such as polypropylene and fluororesin are preferable, they have poor sealing properties and cannot withstand long-term use.

The following technologies are known for pharmaceutical rubber stoppers, but each has many problems. For example, laminates of plastic film and rubber have been proposed, but they have problems with adhesion and sealing, and are unreliable. In addition, although a method for laminating a fluororesin film to rubber is disclosed,
Good luck lies in adhesion, sealability, and hardness. Furthermore, even if a method of improving adhesion by surface treatment of the fluororesin film is employed, the problem remains that the sealed portion is made of film and glass.

For this reason, a method is known in which a joint surface between the rubber and the resin film is left in the sealing part, and a special structure is designed in which the rubber part is used to seal the seal, but neither structure is perfect.

Composite frames coated with a rubber solution are also known, but the butyl rubber surface is susceptible to swelling and other effects from solvents, and it is difficult to pass rigorous tests for infusion stoppers after processing.

In composite drug stoppers with fluororubber, since the fluororubber is finished using a vulcanizing agent, there is a problem of chemical contamination due to the leakage of additives such as the vulcanizing agent, and secondary vulcanization is required. However, since it requires many steps and has higher gas permeability than fluororesin, it needs to be thicker, and as a result, it is unsatisfactory from an economic point of view. Furthermore, if the thickness is large, an adhesive is required, which causes problems in adhesion.

[Objective of the Invention] The object of the present invention is to have a material that is flexible and rubber-elastic, has resistance to chemicals, has an excellent sealing function with the container opening without contaminating the medicine, and has a chemical-resistant material. Contaminating additives (
For example, vulcanizing agents, vulcanization accelerators, acid acceptors, reinforcing materials, etc.)
The rubber stopper is highly safe, does not contain components that can be eluted by hot water, has excellent moldability, and can be manufactured using a cylindrical method with a reduced manufacturing defect rate. It is to donate money.

[Structure of the Invention] This feature is achieved by a laminated rubber stopper in which the rubber is a fluorine-containing thermoplastic rubber, in which a rubber layer is laminated on at least the container mouth insertion portion of the stopper body.

In the present invention, the fluorine-containing thermoplastic rubber refers to a rubber that has vulcanized rubber elasticity at a relatively low temperature (for example, around room temperature) and exhibits plastic flow when heated.

The fluorine-containing thermoplastic rubber preferably consists of at least II elastomeric polymer chain segments and at least II non-elastomeric polymer chain segments, at least one of which is a fluoropolymer chain segment. Particularly preferred is one in which the weight ratio of the elastomeric polymer chain segment to the non-elastomeric polymer chain segment is 40 to 95.5 to 60.

A particularly preferred example of the fluorine-containing thermoplastic rubber is a chain consisting of two or three polymer chain segments, an iodine atom present at one end of the chain, and an iodide compound present at the other end of the chain.
one of the polymer chain segments (if the chain consists of two polymer chain segments) or one or two (if the chain consists of three polymer chain segments) ) is (1) vinylidene fluoride/hexafluoropropylene or pentafluoropropylene/tetrafluoroethylene (molar ratio 45-90:5-50:0-35) polymer and (2) perfluoro(C+-C3 alkyl vinyl ether) [ It also includes those containing multiple ether bonds. Same below. ]/tetrafluoroethylene/vinylidene fluoride (molar ratio 15-75:0-85:
0-85) selected from polymers with a molecular weight of 30.00
0 to 1,200°000 elastomeric polymer chain segments, the remainder of said polymer chain segments being (
3) vinylidene fluoride/tetrafluoroethylene (molar ratio O~100: O~100) polymer and (
4) Ethylene/tetrafluoroethylene/hexafluoropropylene, 3,3.3-)lifluoropropylene-
1,2-trifluoromethyl-3,3゜3-trifluoropropylene-1 or perfluoro(C,~C3 alkyl vinyl ether) (mole ratio 40-60: 60-4
0:0-30) selected from polymers with a molecular weight of 3,0
00 to 400.000 non-elastomeric polymer chain segments, and the weight ratio of elastomeric polymer chain segments to non-elastomeric polymer chain segments is 40 to 95:5 to
60, fluorine-containing thermoplastic rubber.

A preferable fluorine-containing thermoplastic rubber used in the present invention is described in Japanese Patent Publication No. 58-4728.

A typical structure of a fluorine-containing thermoplastic rubber is, for example, the formula: %Formula% [In the formula, Q is a residue obtained by removing an iodine atom from an iodide compound, and A, B, ... are each a polymer chain segment (However, , at least one of which is a fluorine-containing polymer chain segment), ■ represents an iodine atom released from the iodide compound, and n represents the number of bonds in Q. ], basically consisting of a chain consisting of at least two types of polymer chain segments, an iodine atom bonded to both ends of the chain, and a residue obtained by removing at least one iodine atom from an iodide compound. It consists of minutes. Therefore, the at least two types of polymer chain segments are different from each other (for example, the structures and compositions of the monomer units that constitute them are different) from the adjacent polymer chain segments, and their At least one of them is a fluoropolymer chain segment, at least one hard segment and at least one
Consists of soft segments of seeds. Preferably, each polymer chain segment has a molecular i of 3,000 or more, but at least one polymer chain segment has a molecular i of 130,000 or more, excluding so-called telomeric regions. Furthermore, in the case where a polymerizable double bond exists in the iodide compound, the residue obtained by removing at least an iodine atom from the iodide compound is a monomer constituting the polymer chain segment or some substituent derived from the iodide compound. It is Uruchino that has. These fluorine-containing thermoplastic rubbers usually contain 0.001 to 10% by weight of iodine atoms. However, it also includes those in which iodine is removed by reaction or substituted with other residues after thermoplastic rubber synthesis.

The shape of the rubber stopper of the present invention is not particularly limited, and a rubber layer made of fluorine-containing thermoplastic rubber can be easily laminated at the same time as the rubber vulcanization molding even when the rubber stopper has a rectangular shape.

As an example, a method of laminating a rubber stopper having a shape shown in a perspective view in FIG. 1 and in a cross-sectional view in FIG. 2 or 3 will be described. First, a film of fluorine-containing thermoplastic rubber and unvulcanized rubber (corresponding to A in Fig. 2 and A in Fig. 3) are superimposed on the lower mold, and then the upper mold (corresponding to A in Fig. 3) is placed on top of the film. A flat mold (in Fig. 3, a mold with a recess for molding the head of the rubber stopper) is placed, and the rubber is pressurized at a predetermined vulcanization temperature to form and vulcanize the rubber stopper, and at the same time, the rubber stopper part is molded. The base (also referred to as the foot) is laminated with a film 2 of fluorine-containing thermoplastic rubber. Next, cut it into a predetermined size.

In the case of Fig. 2, the raw stopper obtained above is further placed in the lower mold, unvulcanized rubber (A1) is placed on top of it, and a recess is formed for molding the head of the rubber stopper. Place the upper mold and apply pressure at the rubber vulcanization temperature to complete the rubber stopper. For these moldings, it is preferable to use a vacuum molding machine as a compression molding machine.

In the case of the above molding method, the film is rubberized @,
Depending on the temperature, it can be stretched by an average of 4 times, and in special places by about 7 to 8 times. Therefore, a film that is difficult to stretch and cannot withstand these conditions will break during the molding process, resulting in a defective product as a laminated rubber stopper.

Since the fluorine-containing thermoplastic rubber of the present invention is flexible and has rubber elasticity even at the rubber vulcanization temperature, the incidence of such defective products is extremely low. However, powder or pellets of fluorine-containing thermoplastic rubber are first put into a female mold, and then pressurized with a male mold coated with fluororesin to form a film along the female mold, which then becomes the rubber stopper body. The unvulcanized rubber may be placed in a film-covered female mold and vulcanized.

Note that the fluorine-containing thermoplastic rubber of the present invention does not require the addition of a vulcanizing agent like normal fluororubbers, and exhibits the same physical properties as vulcanized rubber simply by cooling after molding, so the addition of a vulcanizing agent is necessary. Moreover, there is no need to add any additives to the pond, so there is no risk of contaminating the chemicals. However, depending on the purpose,
It may be crosslinked, and when crosslinking, known crosslinking methods such as peroxide vulcanization, polyol vulcanization, polyamine vulcanization, etc. can be employed using a vulcanizing agent commonly used for crosslinking fluororubber. It can also be crosslinked by radiation irradiation.

The rubber compound material constituting the rubber stopper of the present invention can be manufactured substantially according to conventional techniques.

Isoprene/isobutylene rubber (IIR), isoprene rubber, butanoene rubber, styrene-butadiene rubber, ethylene-propylene rubber 1. Ethylene-propylene-tene rubber, chlorosulfonated polystyrene, ethylene-
Rubber is produced by blending vinyl acetate copolymer, styrene-isoprene rubber, thermoplastic elastomer, natural rubber, etc. with appropriate vulcanizing agents, vulcanization accelerators, vulcanization activators, processing aids, fillers, reinforcing agents, etc. It can be used as long as it maintains its physical properties and heat resistance as a stopper.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 Fluorine-containing thermoplastic rubber chemical resistance vinylidene fluoride/hexafluoropropylene/
Te1. Lafluoroethylene (molar ratio 50:30:20)
A fluorine-containing thermoplastic rubber (referred to as Rubber A) consisting of 85% by weight of polymer segments and 15% by weight of ethylene/tetrafluoroethylene/hexafluoropropylene (molar ratio 43:49:8) polymer segments;
A fluorine-containing thermoplastic rubber (referred to as Rubber B) in which the latter segment in Rubber A was a polyvinylidene fluoride segment (12% by weight) was tested for chemical resistance.

For comparison, a similar test was conducted using ordinary vulcanized fluororubber (DAIEL C; 701, manufactured by Daikin Industries, Ltd.).

Rubber sample (l OmmX 2 OmmX thickness 2 +nm
) was immersed in the chemicals shown in Table 1 under the conditions shown in the same table, and then the volume change (%) was measured. The results are shown in the same table.

Comparative Example 1 The same test as in Example 1 was conducted using commercially available silicone rubber stoppers, cork stoppers, natural rubber stoppers, and butyl rubber stoppers, but all of them had appearance and shapes that were unusable. Measurement was not possible.

Example 2 and Comparative Example 2 Gas permeability tests of Rubber A and Rubber B of Example 1 and natural rubber were conducted according to the method of ASTM D143C-M. The results are shown in Table 2.

Example 3 and Comparative Example 3 Test pieces (10
0mmX IOOmmX Thickness 1mm), 1210
The sample was subjected to elution treatment with hot water at C for 60 minutes, and the degree of turbidity of the treated solution and the presence or absence of metal ions in the treated solution were measured by atomic absorption spectrophotometry. The results are shown in Table 3. Note that the amount of metal eluted is expressed in ppm. Also, * indicates that it was below the detection limit.

Table 3

[Brief explanation of drawings]

FIG. 1 is a perspective view of a laminated rubber stopper of the present invention, and FIG. 2 is a sectional view of a rubber stopper in which only the element components are laminated.
and FIG. 3 is a sectional view of a rubber stopper in which the element part and the lower surface of the head are laminated. 1... Rubber stopper, 2... Fluorine-containing thermoplastic rubber film.

Claims (1)

[Scope of Claims] 1. A rubber stopper in which a rubber layer is laminated on at least the container mouth insertion portion of the stopper body, the rubber being a fluorine-containing thermoplastic rubber. 2. The laminated rubber stopper according to claim 1, wherein the rubber layer has a thickness of 0.1 to 0.5 mm. 3. Fluorine-containing thermoplastic rubber comprising at least one elastomeric polymer chain segment and at least one non-elastomeric polymer chain segment, at least one of which is a fluorine-containing polymer chain segment. The first claim is
The laminated rubber stopper according to item 1 or 2. 4. The laminate rubber stopper according to claim 3, wherein the fluorine-containing thermoplastic rubber comprises 40 to 95 parts by weight of elastomeric polymer chain segments and 5 to 60 parts by weight of non-elastomeric polymer chain segments. 5. The melting point of the non-elastomeric polymer chain segment is 19
The laminated rubber stopper according to claim 3 or 4, which has a temperature of 0° C. or lower. 6. The laminate rubber stopper according to any one of claims 1 to 5, which is a crosslinked fluorine-containing thermoplastic rubber.