Cleaning and silicification-free production process for butyl rubber plug

Abstract

The invention discloses a cleaning and silicification-free production process for a butyl rubber plug. The cleaning and silicification-free production process comprises the following steps: S01, spraying a release agent on a mold closing surface of a vulcanization mold of the butyl rubber plug; s02, placing the calendered rubber sheet in a vulcanization mold, and closing the mold for vulcanization; s03, taking out the rubber plug molding connecting sheet from the vulcanization mold, spreading, atomizing and spraying a curing liquid to the rubber plug molding connecting sheet, and curing to form a film; s04, rubber plug forming connecting pieces are cut, and butyl rubber plugs are cleaned and dried; the release agent is mainly composed of hydroxyl-terminated polydimethylsiloxane, a wetting agent and a first solvent. The curing liquid mainly comprises an end-capping reagent, a catalyst and a second solvent; the end-capping reagent is hydroxyl silicone oil with the viscosity of 45-100 cSt at the temperature of 20 DEG C, and the catalyst is an acid catalyst. Hydroxyl-terminated polydimethylsiloxane is introduced into the surface of the rubber plug through vulcanization, a catalyst and an end-capping reagent are atomized and sprayed, and waste heat of a vulcanized rubber sheet is used for thermocuring and film forming, so that the production steps of the rubber plug are simplified, and the production efficiency of the rubber plug is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rubber, and in particular to a cleaning and silicon-free production process for a butyl rubber plug and a preparation method thereof. Background Art

[0002] The production process of rubber plugs includes the following steps: rubber mixing, calendering into sheets, vulcanization molding, slitting, cleaning, drying, packaging, etc. In order to prevent the rubber plugs from sticking during packaging and transportation and ensure the continuous plugging and smooth plugging of pharmaceutical filling equipment, dimethyl silicone oil is usually added to the cleaning liquid of the rubber plugs so that the surface of the rubber plugs after drying is adhered to dimethyl silicone oil, which is also called cleaning siliconization.

[0003] The dimethyl silicone oil layer formed by cleaning and silicification has the following defects: when the filled drugs are sterilized under high pressure with plugs, part of the silicone oil will detach from the surface of the plug, which will cause metal ions such as calcium, aluminum, zinc, lead and other heavy metals to be extracted and dissolved by the drugs, affecting the clarity and metal ion content of the drugs, and there is a risk of secondary contamination of the drugs; the amount of silicone oil on the surface of the plugs made by cleaning and silicification is difficult to control. In addition, the silicone oil is also unevenly distributed on the surface of the plugs.

[0004] The improved technical solution is disclosed in 202010703498.3. First, the end-capped dimethylsiloxane, catalyst and coupling agent, organic solvent and curing agent are mixed to obtain a spray liquid, and then the spray liquid is applied to the predetermined area of ​​the rubber plug to be sprayed. The spray liquid reacts on the predetermined surface of the rubber plug and finally solidifies to form a siliconized coating with excellent adhesion. Another example is CN107629240A. The above solutions are all for spraying, heat curing or UV curing of clean rubber plugs that have been washed and dried, and the production steps are numerous. Summary of the invention

[0005] One of the purposes of the present invention is to overcome the defects existing in the prior art and provide a cleaning and silicon-free production process for butyl rubber plugs, wherein hydroxyl-terminated polydimethylsiloxane is introduced into the surface of the rubber plug through a vulcanized release agent, a catalyst and a capping agent are sprayed by atomization, and the waste heat of the vulcanized rubber sheet is utilized to polycondense silanol on the surface of the rubber plug to form a barrier layer, which is beneficial to simplifying the production steps of the rubber plugs and improving the production efficiency of the rubber plugs.

[0006] In order to achieve the above technical effects, the technical solution of the present invention is: a cleaning and silicon-free production process for butyl rubber stoppers, comprising the following steps:

[0007] S01, spraying a release agent on the mating surface of the vulcanization mold of the butyl rubber plug;

[0008] S02, placing the calendered rubber sheet in the vulcanization mold, closing the mold and vulcanizing;

[0009] S03, taking out the rubber plug forming piece from the vulcanization mold, spreading it, and spraying a curing liquid on the rubber plug forming piece, so that the curing liquid is cured to form a film on the surface of the rubber plug forming piece;

[0010] S04, cutting the rubber plug into pieces to obtain butyl rubber plugs, and washing and drying the butyl rubber plugs;

[0011] The main components of the release agent are hydroxyl-terminated polydimethylsiloxane, a wetting agent and a first solvent;

[0012] The main components of the curing liquid are a capping agent, a catalyst and a second solvent;

[0013] The end-capping agent is hydroxy silicone oil with a viscosity of 45 to 100 cSt at 20° C., and the catalyst is an acid catalyst.

[0014] The viscosity of the end-capping agent hydroxy silicone oil at 20° C. can be specifically selected as 45 cSt, 55 cSt, 65 cSt, 75 cSt, 85 cSt, 95 cSt, 100 cSt point values ​​or an interval with the above two point values ​​as the maximum and minimum values.

[0015] The preferred technical solution is that the viscosity of the hydroxyl-terminated polydimethylsiloxane at 20°C is 10000-70000 cSt, and the mass percentage of the hydroxyl-terminated polydimethylsiloxane in the release agent is 14%-25%. The viscosity of the hydroxyl-terminated polydimethylsiloxane at 20°C can be specifically selected as 10000 cSt, 20000 cSt, 30000 cSt, 40000 cSt, 50000 cSt, 60000 cSt, 70000 cSt, or an interval with the above two point values ​​as the maximum and minimum values.

[0016] The preferred technical solution is that the first solvent is at least one selected from ethanol, acetone, butanol, and ethyl acetate, the wetting agent is a long-chain alkyl silane, and the mass percentage of the wetting agent in the release agent is 0.02% to 0.25%. The mass percentage of the wetting agent in the release agent can be specifically selected as 0.02%, 0.05%, 0.075%, 0.1%, 0.12%, 0.15%, 0.175%, 0.2%, 0.225%, 0.25% or an interval with the above two points as the maximum and minimum values.

[0017] The preferred technical solution is that the mold closing vulcanization temperature in S02 is 150-180°C, and the curing temperature in S03 is not less than 120°C. The mold closing vulcanization temperature in S02 can be specifically selected as 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, or an interval with the above two point values ​​as the maximum and minimum values; usually, the rubber plug forming piece exchanges heat with the surrounding air during the process of being taken out of the vulcanization mold and spread on the operating platform, and the temperature drops slightly; further, the curing temperature in S03 is 120°C-145°C.

[0018] The preferred technical solution is that the catalyst is at least one selected from aminomethylphosphonic acid and methylphosphonic acid; the second solvent is water, and the pH value of the solidifying liquid is 3.5 to 5. The pH value of the solidifying liquid can be specifically selected as 3.5, 3.7, 4, 4.2, 4.7, 5 points or an interval with the above two points as the maximum and minimum values.

[0019] The preferred technical solution is that the mass percentage of the end-capping agent in the solidifying liquid is 1% to 4.5%. The mass percentage of the end-capping agent in the solidifying liquid can be specifically selected as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or an interval with the above two points as the maximum and minimum values.

[0020] A preferred technical solution is that the hydroxyl-terminated polydimethylsiloxane is α,ω-dihydroxy polydimethylsiloxane.

[0021] The preferred technical solution is that the long-chain alkyl silane is a silane compound having a C12-C20 long-chain alkyl group. Specifically, the long-chain alkyl silane is at least one selected from dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, and octadecyltriethoxysilane.

[0022] The preferred technical solution is that the raw material composition of the calendered film includes: 100 parts of halogenated butyl rubber, 1-2 parts of magnesium oxide, 0.1-0.6 parts of tetrabenzylthiuram disulfide, 0.1-0.2 parts of carbon black as a colorant, 70-85 parts of calcined kaolin, 10-17 parts of high-density polyethylene powder, 1-2 parts of titanium dioxide as a colorant, and 2-3 parts of phenolic resin. Furthermore, the raw materials of the calendered film do not contain internal mold release agents, such as zinc stearate, polyethylene wax powder, etc.

[0023] The second object of the present invention is to provide a butyl rubber plug, which is produced by the above-mentioned butyl rubber plug cleaning and silicon-free production process.

[0024] The advantages and beneficial effects of the present invention are:

[0025] The silicon-free washing production process for cleaning butyl rubber plugs comprises spraying a release agent containing hydroxyl-terminated polydimethylsiloxane in a vulcanization mold, and the hydroxyl-terminated polydimethylsiloxane adheres to the surface of the vulcanized rubber plug. A curing liquid containing a capping agent and a catalyst is further sprayed, and the hydroxyl-terminated polydimethylsiloxane, the wetting agent and the capping agent undergo a polymerization reaction using the residual heat of the vulcanized rubber plug, thereby forming a polysiloxane layer with stable adhesion and good isolation performance on the surface of the rubber plug.

[0026] The polysiloxane layer is resistant to post-cleaning in the production process of rubber plugs. The clarity of the drug and the dissolution of metal ions during the assembly and use of the rubber plugs meet the packaging requirements of conventional sodium chloride and glucose injections.

[0027] Different from the production steps of first cleaning and drying and then spraying the treatment liquid on the surface and curing in the prior art, the cleaning and silicon-free production process has simple steps and is conducive to improving the production efficiency of butyl rubber plugs. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0031] Example

[0032] The raw material composition of the rubber plug of Example 1 is: 100 parts of chlorinated butyl rubber (ExxonMobil 1066), 1.5 parts of magnesium oxide (particle size 1250 mesh), 0.2 parts of tetrabenzylthiuram disulfide (Huangyan Donghai Chemical), 0.12 parts of colorant carbon black (particle size 3000 mesh, Mitsubishi, Japan), 78 parts of calcined kaolin (particle size 1250 mesh, Inner Mongolia Sanxin), 15 parts of high-density polyethylene powder (Nanjing Tengyi, 3000 mesh), 1.5 parts of colorant titanium dioxide (Zhenjiang Panhua, 2000 mesh), and 2.3 parts of phenolic resin (USA Saint-LeCoultre).

[0033] Example 1 The production process of chlorobutyl rubber plugs is carried out according to the following steps:

[0034] S1: Rubber mixing: colorants titanium dioxide, magnesium oxide, calcined kaolin, magnesium oxide and high-density polyethylene powder are added to chlorobutyl rubber in sequence, and the mixing is carried out for 6 minutes. The rubber discharge temperature is controlled at 110±5℃; the rubber is introduced into an open mixer, phenolic resin and tetrabenzylthiuram disulfide are added, and the mixing is carried out for 3 minutes. The mixed rubber is cooled;

[0035] S2: The mixed rubber is introduced into a calender and pressed into a predetermined thickness, and then cut according to the quality and size required by the vulcanization mold to obtain a vulcanized rubber sheet;

[0036] S3: Prepare the release agent and curing liquid according to the following composition:

[0037] Release agent: 17 parts of α, ω-dihydroxy polydimethylsiloxane (viscosity 50,000 cSt at 20° C.), 0.15 parts of wetting agent dodecyltrimethylsilane, and 82.85 parts of first solvent ethanol.

[0038] Curing liquid: prepare a dilute solution of catalyst benzenesulfonic acid, mix 3.7 parts of end-capping agent hydroxy silicone oil (viscosity 67 cSt at 20°C) with 90 parts of the second solvent water, add dilute methanesulfonic acid solution dropwise to adjust the pH value to 4.1, and add water to quantify to 100 parts.

[0039] S4: spraying the release agent onto the mating surface of the vulcanization mold of the butyl rubber plug;

[0040] S5: Place the calendered film in a vulcanization mold and close the mold for vulcanization; in S02, the mold closing vulcanization temperature is 170±5℃, the vulcanization pressure is 11MPa, and the vulcanization time is 350s;

[0041] S6: Take out the rubber plug forming piece from the vulcanization mold, spread it on the operating table, use infrared temperature measuring equipment to test the surface temperature of the rubber plug forming piece to be 140℃±3, spray the curing liquid on the neck side of the rubber plug forming piece, let it stand for 30s, then turn the rubber plug forming piece over, spray the curing liquid on the neck side of the rubber plug forming piece, let it stand for 30s (the surface temperature of the rubber plug forming piece is measured to be 125±3℃ after standing), and remove the remaining curing liquid droplets in the atomized spraying space above the operating table through suction and removal by the top air induced mechanism;

[0042] S7: Punch and cut the rubber plug into pieces to obtain butyl rubber plugs, and then clean and dry the butyl rubber plugs.

[0043] Example 2

[0044] Example 2 is based on Example 1, except that the hydroxyl-terminated polydimethylsiloxane is α-hydrogen-ω-hydroxy-polydimethylsiloxane (viscosity of 50,000 cSt at 20° C.).

[0045] Example 3

[0046] Example 3 is based on Example 1, except that the catalyst in the solidifying liquid is methylphosphonic acid.

[0047] Example 4

[0048] Example 4 is based on Example 3, except that the wetting agent in the release agent is lauryl alcohol (dodecyl alcohol).

[0049] Example 5

[0050] Example 5 is based on Example 3, except that, S6: the plug molded piece is taken out from the vulcanization mold, spread on the operating table, and allowed to stand and cool. The surface temperature of the plug molded piece is tested by infrared temperature measuring equipment to be 120°C. Then, the plug temperature is atomized and sprayed with curing liquid on the plug neck side of the plug molded piece, and the plug is allowed to stand for 30 seconds. Then, the plug molded piece is turned over, and the curing liquid is atomized and sprayed on the plug neck side of the plug molded piece, and the plug is allowed to stand for 30 seconds (the surface temperature of the plug molded piece is measured to be 103±3°C after the standing is completed).

[0051] Example 6

[0052] Example 5 is based on Example 3, except that the mass percentage of the end-capping agent in the solidifying liquid is 5.5%.

[0053] Comparative Example 1

[0054] Based on Example 3, the composition of the release agent of Comparative Example 1 is: 17 parts of α, ω-dihydroxypolydimethylsiloxane (viscosity of 50,000 cSt at 20° C.), 83 parts of the first solvent ethanol, and does not contain the wetting agent dodecyltrimethylsilane.

[0055] Comparative Example 2

[0056] Based on Example 3, the composition of the release agent of Comparative Example 2 is: 2 parts of polydimethylsiloxane (viscosity is 50,000 cSt at 20°C), 15 parts of α, ω-dihydroxy-polydimethylsiloxane (viscosity is 50,000 cSt at 20°C), 0.15 parts of wetting agent dodecyltrimethylsilane, and 83 parts of the first solvent ethanol.

[0057] Performance test of rubber plugs of examples and comparative examples:

[0058] 1. Coating adhesion test: The coating adhesion is tested by the cross-cut method. The evaluation criteria are as follows:

[0059] No coating falls off at the intersection of the cuts, which is marked as ●;

[0060] A small amount of coating falls off at the intersection of the cuts, and the cross-cut area affected is no more than 2%, which is counted as ◎;

[0061] A small amount of coating fell off at the intersection of the cuts, and the cross-cut area was affected by no more than 5%, which was rated as ○.

[0062] 2. Silicone oil particles in treated rubber plugs: Take three batches of finished injection rubber plugs from two groups from the same batch, refer to the light obstruction method in the determination method of insoluble particles in packaging materials YBB00272016 issued by the State Food and Drug Administration, conduct silicone oil particle test (detect silicone oil particles with two particle sizes of ≥10μm and ≥25μm), and take the average value;

[0063] 3. Turbidity of rubber stopper after treatment: The sample control package is amobarbital sodium (alkaline), which is inverted and subjected to high temperature experiments at constant temperature and humidity conditions (60°C, 75% RH) for 10 days, 20 days, and 30 days to compare the turbidity.

[0064] The test results of the examples and comparative samples are shown in the table below:

[0065]

[0066] It can be seen from the test results in the above table that the silicone oil particle detection in the embodiment meets the following qualified requirements: the number of insoluble particles larger than 10 μm in each 1 mL of infusion should be less than 12 particles, and the number of insoluble particles larger than 25 μm should be less than 2 particles;

[0067] Among them, the adhesion of the siloxane layer of Example 3 and Example 6 is evaluated to be better. Excessive use of the end-capping agent will lead to a significant increase in the number of small-particle silicone oil particles. The preferred α, ω-dihydroxy polydimethylsiloxane, the curing liquid catalyst methylphosphonic acid, the wetting agent dodecyltrimethylsilane, the curing temperature above 120°C and the end-capping agent content in the curing liquid are all conducive to improving the adhesion of the siloxane layer and reducing the number of silicone oil particles, thereby ensuring the clarity of the drug.

[0068] The comparison between Example 3 and Comparative Examples 1 and 2 shows that the wetting agent component in the release agent is necessary, which helps to increase the adhesion amount of hydroxyl-terminated polydimethylsiloxane on the surface of the rubber plug after vulcanization treatment and facilitates the uniform distribution of hydroxyl-terminated polydimethylsiloxane on the surface of the vulcanized semi-finished product; the polydimethylsiloxane in the release agent will also detach from the rubber plug to form silicone oil particles, thereby adversely affecting the clarity of the drug.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A butyl rubber stopper cleaning and silicon-free production process, characterized in that: The following steps are involved: S01, spraying a release agent on the mating surface of the vulcanization mold of the butyl rubber plug; S02, placing the calendered rubber sheet in the vulcanization mold, closing the mold and vulcanizing; S03, taking out the rubber plug forming piece from the vulcanization mold, spreading it, and spraying a curing liquid on the rubber plug forming piece, so that the curing liquid is cured to form a film on the surface of the rubber plug forming piece; S04, cutting the rubber plug into pieces to obtain butyl rubber plugs, and washing and drying the butyl rubber plugs; The main components of the release agent are hydroxyl-terminated polydimethylsiloxane, a wetting agent, and a first solvent; The main components of the curing liquid are a capping agent, a catalyst and a second solvent; The end-capping agent is hydroxy silicone oil with a viscosity of 45 to 100 cSt at 20° C., and the catalyst is an acid catalyst.

2. The cleaning and silicon-free production process for butyl rubber stoppers according to claim 1 is characterized in that: The viscosity of the hydroxyl-terminated polydimethylsiloxane at 20° C. is 10,000 to 70,000 cSt, and the mass percentage of the hydroxyl-terminated polydimethylsiloxane in the release agent is 14% to 25%.

3. The cleaning and silicon-free production process for butyl rubber plugs according to claim 1 is characterized in that: The first solvent is at least one selected from ethanol, acetone, butanol, and ethyl acetate; the wetting agent is a long-chain alkyl silane; and the mass percentage of the wetting agent in the release agent is 0.02% to 0.25%.

4. The cleaning and silicon-free production process for butyl rubber stoppers according to claim 1, characterized in that: The mold vulcanization temperature in S02 is 150-180°C, and the curing temperature in S03 is not less than 120°C.

5. The cleaning and silicon-free production process for butyl rubber stoppers according to claim 1, characterized in that: The catalyst is at least one selected from aminomethylphosphonic acid and methylphosphonic acid; the second solvent is water, and the pH value of the solidifying liquid is 3.5-5.

6. The cleaning and silicon-free production process for butyl rubber stoppers according to claim 1, characterized in that: The mass percentage of the end-capping agent in the solidifying liquid is 1% to 4.5%.

7. The cleaning and silicon-free production process for butyl rubber plugs according to claim 1, characterized in that: The hydroxyl-terminated polydimethylsiloxane is α,ω-dihydroxy polydimethylsiloxane.

8. The cleaning and silicon-free production process for butyl rubber plugs according to claim 3, characterized in that: The long-chain alkylsilane is a silane compound having a C12-C20 long-chain alkyl group.

9. The cleaning and silicon-free production process for butyl rubber plugs according to claim 1, characterized in that: The raw material composition of the calendered film includes: 100 parts of halogenated butyl rubber, 1-2 parts of magnesium oxide, 0.1-0.6 parts of tetrabenzylthiuram disulfide, 0.1-0.2 parts of carbon black as a colorant, 70-85 parts of calcined kaolin, 10-17 parts of high-density polyethylene powder, 1-2 parts of titanium dioxide as a colorant, and 2-3 parts of phenolic resin.

10. A butyl rubber plug, characterized in that: The butyl rubber plug is produced by the cleaning and silicon-free production process of any one of claims 1 to 9.

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