Method for using capsule release agent and a permanent capsule release agent and preparation method thereof

Abstract

The present invention provides a method for using a capsule release agent and a permanent capsule release agent and preparation method. The method for using the capsule release agent comprises the following steps: S1, heating the capsule to 120-230°C; S2, applying the capsule release agent to the surface of the capsule obtained in step S1; and S3, baking the capsules coated with the capsule release agent obtained in step S2 at 120-230°C. The permanent capsule release agent of the present invention is an active polymer emulsion that is stable under acidic (pH between 4-7) room temperature conditions and can continue to crosslink and form a film at high temperatures. Once the capsule is coated with the permanent capsule release agent, it can be continuously vulcanized hundreds of times. The present invention also adjusts the ratio of the hydrogenated silicone oil emulsion to the silicone resin emulsion. This change in proportions brings substantial improvements to the product, increases production efficiency, and reduces overall production costs for the enterprise.

Description

Technical Field

[0001] The present invention relates to the field of release agents, and more particularly to a method for using a capsule release agent, a method for using a permanent capsule release agent, and a permanent capsule release agent and a preparation method thereof. Background Art

[0002] The production of pneumatic tires requires a vulcanization process, which typically uses mold pressurization. This type of vulcanization is characterized by the outer surface of the rubber embryo in contact with the metal mold, and the inner surface in contact with the bladder. During the vulcanization process, the inflated bladder exerts pressure on the embryo and the metal mold, helping to shape the tire's outer tread and inner surface. To prevent adhesion between the bladder and the rubber embryo, a lubricating release agent with mold release properties is required. This type of release agent has evolved over decades, from initial materials such as soap powder and talcum powder to silicone oil, silicone rubber solutions, and emulsified silicone oil. Currently, there are three main anti-sticking methods used domestically and internationally: using only a capsule release agent, using only a green tire internal spray, or using a combination of a capsule release agent and a green tire internal spray. Only a few companies use only green tire sprays, and each tire must be sprayed, requiring a significant amount of application. Some companies still use a combination of capsule release agents and green tire sprays, but this approach is wasteful in both labor and material costs. This is particularly true given the current international situation, where foreign markets are increasing their anti-dumping measures against Chinese tires, forcing domestic tire manufacturers to reduce production costs in all aspects. Consequently, most companies have eliminated green tire sprays and switched to capsule release agents, which offer superior mold release and durability. However, the quality of capsule release agents currently available on the market varies widely, with most requiring reapplication after only a few to a dozen vulcanization cycles, and some even requiring reapplication every vulcanization cycle. Chinese patent publication number CN109895296A discloses a vulcanization release agent that can be demolded up to 20 times with a single application, making it a semi-permanent vulcanization release agent. We assume that the average number of times a capsule is used is 300 times. If a release agent is applied after each vulcanization, 300 applications will be required. In the high-temperature working environment of the vulcanization workshop, the operating intensity of the vulcanizer will increase, and production efficiency will be greatly reduced. Therefore, as tire manufacturers increasingly demand continuous and automated production processes, the performance and operation methods of ordinary capsule release agents can no longer meet the needs. A new generation of high-performance release agents has not yet emerged domestically or internationally to meet the demand. In contrast to semi-permanent vulcanization release agents, when a capsule is coated with a capsule release agent once and can be continuously vulcanized hundreds of times until the capsule reaches its service life, this capsule release agent is called a permanent release agent. In view of the problems and defects of the existing technology, the research and development of permanent release agents is of great significance. Summary of the Invention

[0003] The present invention provides a method for using a capsule release agent, a method for using a permanent capsule release agent, a permanent capsule release agent, and a method for preparing a permanent capsule release agent. The specific technical solutions are as follows:

[0004] A method for using a capsule release agent, comprising the following steps:

[0005] S1. Heat the capsule to 120-230°C;

[0006] S2. Applying a capsule release agent to the surface of the capsule obtained in step S1;

[0007] S3, baking the capsules coated with the capsule release agent obtained in step S2 at 120° C.-230° C.;

[0008] Furthermore, the airing time in step S2 is 0.5-2h;

[0009] Furthermore, the baking time in step S3 is 0.5-1.5 hours.

[0010] A method for using a permanent capsule release agent adopts the above-mentioned method for using a capsule release agent. The permanent capsule release agent comprises, by mass, 5-10 parts of silicone resin emulsion, 20-30 parts of hydrogenated silicone oil emulsion, 0.05-1 part of silica sol, and 70-75 parts of water.

[0011] A permanent capsule release agent, comprising, by mass: 8 parts of silicone resin emulsion, 20 parts of hydrogenated silicone oil emulsion, 0.5 parts of silica sol, and 72 parts of water;

[0012] Furthermore, the composition comprises, by mass: 6 parts of silicone resin emulsion, 25 parts of hydrogenated silicone oil emulsion, 0.1 parts of silica sol, and 74 parts of water;

[0013] Furthermore, the usage ratio of the silicone resin emulsion to the hydrogenated silicone oil emulsion is 1:2-3;

[0014] Furthermore, the ratio of the hydrogenated silicone oil emulsion to the silicone resin emulsion is 2.5:1;

[0015] Furthermore, the silicone resin emulsion comprises, by mass, 65-75 parts of organosilicon monomer, 0.4-0.6 parts of organic acid catalyst, 1-1.5 parts of emulsifier, and 23-34 parts of water;

[0016] Furthermore, the silicone resin emulsion comprises, by mass, 70 parts of organosilicon monomer, 0.5 parts of organic acid catalyst, 1.3 parts of emulsifier, and 30 parts of water;

[0017] Furthermore, the silicone resin emulsion comprises, by mass, 68 parts of organosilicon monomer, 0.4 parts of organic acid catalyst, 1.2 parts of emulsifier, and 26 parts of water;

[0018] Furthermore, the organic acid catalyst is alkylbenzenesulfonic acid or chloroplatinic acid;

[0019] Furthermore, the organosilicon monomer is octamethylcyclotetrasiloxane;

[0020] Furthermore, the permanent capsule isolation agent also includes 0.01-1 parts of a bactericide;

[0021] A method for preparing a permanent capsule release agent comprises the following steps:

[0022] (1) adding silicone resin emulsion to water at 70-95° C. to obtain solution A;

[0023] (2) adding hydrogenated silicone oil emulsion to solution A and stirring for 3-5 hours to obtain solution B;

[0024] (3) Adding silica sol to solution B and stirring for 2-3 hours to obtain solution C;

[0025] (4) After the solution C is cooled, a permanent capsule release agent is obtained;

[0026] Furthermore, in step (1), a silicone resin emulsion is added to water at 80°C;

[0027] Further, in step (2), solution B is obtained after stirring for 4 hours;

[0028] Furthermore, in step (4), after the solution C is cooled, a bactericide is added to obtain a permanent capsule release agent;

[0029] Furthermore, in step (4), the temperature of solution C is lowered to 35-45°C.

[0030] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are:

[0031] 1. The present invention designs a new method for using a capsule release agent. By controlling the temperature of the capsule and baking the capsule coated with the capsule release agent, compared with the existing technology that directly applies the agent to the capsule or to the inner wall of the tire embryo and then starts vulcanizing the tire, the number of continuous demolding times of the capsule is greatly increased;

[0032] 2. In the prior art, the components of the capsule release agent do not contain silica sol. However, the permanent capsule release agent of the present invention contains silica sol. It is stable under acidic conditions at room temperature and can continue to crosslink to form a film at high temperature. It can improve the hardness, adhesion, impact resistance and other properties of the cross-linked release layer, and further increase the number of vulcanization demoulding times of the capsule.

[0033] 3. In the prior art, the amount of silicone resin emulsion used is greater than the amount of hydrogen silicone oil emulsion used. The present invention adjusts the ratio of hydrogen silicone oil emulsion to silicone resin emulsion so that the amount of silicone resin emulsion used is less than the amount of hydrogen silicone oil emulsion. This change in proportion brings substantial improvement to the product, improves production efficiency, and reduces production costs for enterprises. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] A method for using a capsule release agent comprises the following steps: S1, heating the capsule to 120-230°C; S2, applying the capsule release agent to the surface of the capsule obtained in step S1; S3, baking the capsule obtained in step S2 and coated with the capsule release agent at 120-230°C. The air-drying time in step S2 is 0.5-2h; the baking time in step S3 is 0.5-1.5h. Specifically, if the baking temperature is less than 120°C, the release agent dries slowly after being applied, affecting subsequent steps; if the baking temperature is greater than 230°C, the molecular chain of the capsule glue is destroyed due to the high temperature, affecting its aging resistance. If the baking time is less than 0.5h, the cross-linked film formed on the surface of the capsule is incomplete, affecting the demolding effect; theoretically, extending the baking time can significantly increase the number of demolding attempts. Considering time and economic costs, the baking time should not be too long, and it can be within 1.5h.

[0036] The invention has designed a new method for using a capsule release agent. By controlling the temperature of the capsule and baking the capsule coated with the capsule release agent, compared to the existing technology that directly applies the agent to the capsule or to the inner wall of the tire embryo and then begins vulcanizing the tire, the invention significantly increases the number of consecutive capsule demolding times compared to the existing technology. Furthermore, a method for using a permanent capsule release agent is designed, which adopts the above-mentioned method for using a capsule release agent. The permanent capsule release agent includes, by weight, 5-10 parts silicone resin emulsion, 20-30 parts hydrogenated silicone oil emulsion, 0.05-1 part silica sol, and 70-75 parts water. The permanent capsule release agent undergoes a series of complex reactions under heating conditions, including:

[0037] (1) Condensation between hydroxyl groups of hydroxyl silicone oil in silicone resin emulsion

[0038]

[0039] (2) The hydrolysis of hydrogenated silicone oil in hydrogenated silicone oil emulsion releases hydrogen into silanol groups

[0040] 2(CH3)3[Si(H)(CH3)O] a [Si(CH3)2O] b -Si(CH3)3→(CH3)3[Si(oH)(CH3)O] c [Si(CH3)2O] d -Si(CH3)3+H2

[0041] (3) The hydroxyl groups of the hydrolyzed hydrogenated silicone oil in the hydrogenated silicone oil emulsion can undergo dehydration and condensation polymerization with their own hydroxyl groups, with the hydroxyl groups of another hydroxylated hydrogenated silicone oil, or with the hydroxyl groups in the hydroxylated silicone oil emulsion, forming a three-dimensional network crosslinking. At the same time, as a rubber product, the capsule has some active centers on its surface that can react with hydrogenated or hydroxylated silicone oils, such as hydroxyl groups and carboxyl groups in rubber molecules, resins, and coupling agents. These active centers can react with the silicone in the release agent at high temperatures, and this reaction is more conducive to the formation of a protective film on the capsule surface.

[0042] From the above reaction process, it can be seen that the permanent capsule isolation agent is a one-component silicone resin aqueous emulsion containing active groups [-OH] and [-H]. The active groups [-OH] and [-H] do not polymerize under acidic and low temperature conditions, but will further polymerize under high temperature conditions to become silicone rubber with a larger molecular weight attached to the capsule, and at the same time combine with the active center on the surface of the capsule to form a dense and tough permanent protective film on its surface, which plays a permanent isolation effect.

[0043] A permanent capsule release agent comprises, by mass, 5-10 parts of silicone resin emulsion, 20-30 parts of hydrogenated silicone oil emulsion, 0.05-1 part of silica sol, and 70-75 parts of water. The permanent capsule release agent is a milky white liquid with a pH of 3-6. Furthermore, the dosage ratio of hydrogenated silicone oil emulsion to silicone resin emulsion is 2-3:1; preferably, the dosage ratio of hydrogenated silicone oil emulsion to silicone resin emulsion is 2.5:1. After a large amount of practical research, the present invention has found that when the addition ratio of hydrogenated silicone oil to silicone resin emulsion is 2.5:1, that is, when the addition amount of hydrogenated silicone oil is 2.5 times that of silicone resin emulsion, the number of demolding times can be greatly increased, and the number of demolding times can be increased to 300 times.

[0044] The permanent capsule isolation agent also includes 0.01-1 parts of bactericide.

[0045] The silicone resin emulsion comprises, by weight, 65-75 parts of an organosilicon monomer, 0.4-0.6 parts of an organic acid catalyst, 1-1.5 parts of an emulsifier, and 23-34 parts of water. The organic acid catalyst is alkylbenzenesulfonic acid or chloroplatinic acid. The organosilicon monomer is heated to 70-95°C in a water system with an organic acid catalyst and allowed to react with steady stirring for 5-10 hours to obtain the silicone resin emulsion. The organosilicon monomer can be octamethylcyclotetrasiloxane. The specific process is as follows:

[0046] (1) First, the organosilicon monomer reacts under the action of a catalyst to generate hydroxyl silicone oil;

[0047]

[0048] (2) Hydroxy silicone oil reacts with emulsifier to form silicone resin emulsion (i.e. hydroxy silicone oil emulsion) in water.

[0049]

[0050] A method for preparing the above-mentioned permanent capsule release agent comprises the following steps: (1) adding silicone resin emulsion to water at 70-95° C. to obtain solution A;

[0051] (2) adding hydrogenated silicone oil emulsion to solution A and stirring for 3-5 hours to obtain solution B;

[0052] (3) Adding silica sol to solution B and stirring for 2-3 hours to obtain solution C;

[0053] (4) After the solution C is cooled, a permanent capsule release agent is obtained;

[0054] Furthermore, in step (1), a silicone resin emulsion is added to water at 80°C;

[0055] Further, in step (2), solution B is obtained after stirring for 4 hours;

[0056] Furthermore, in step (4), after the solution C is cooled, a bactericide is added to obtain a permanent capsule release agent;

[0057] Furthermore, in step (4), the temperature of solution C is lowered to 35-45°C.

[0058] Hydrogenated silicone oil emulsions, silicone resin emulsions (hydroxy silicone oil emulsions), and water will also undergo a series of complex molecular weight rearrangements (usually condensation and dehydration between hydroxyl groups) and functional group reactions. Controlling the temperature and pH during the synthesis process allows these reactions to be controlled and to exist stably at room temperature.

[0059] Example 1

[0060] (1) Preparation of silicone resin emulsion

[0061] The silicone resin emulsion comprises, by mass, 65 parts of octamethylcyclotetrasiloxane, 0.4 parts of alkylbenzenesulfonic acid, 1 part of emulsifier, and 23 parts of water.

[0062] Preparation method of silicone resin emulsion: add 65 parts of octamethylcyclotetrasiloxane and 0.4 parts of alkylbenzenesulfonic acid to 23 parts of water, then add 1 part of emulsifier, heat to 70°C, and stir steadily for 10 hours to obtain silicone resin emulsion.

[0063] (2) Preparation of permanent capsule release agent:

[0064] The permanent capsule release agent comprises, by mass, 5 parts of silicone resin emulsion, 20 parts of hydrogenated silicone oil emulsion, 0.05 parts of silica sol, 0.01 parts of fungicide and 70 parts of water.

[0065] Preparation method of permanent capsule release agent: at 70°C, add 5 parts of silicone resin emulsion in step (1) to 70 parts of water and then add 20 parts of hydrogenated silicone oil emulsion, stir for 5 hours, then add 0.05 parts of silica sol and stir for another 3 hours, cool to 35°C, add 0.01 parts of fungicide, and package after passing the test to obtain permanent capsule release agent.

[0066] Example 2

[0067] (1) Preparation of silicone resin emulsion

[0068] The silicone resin emulsion comprises, by mass, 75 parts of octamethylcyclotetrasiloxane, 0.6 parts of chloroplatinic acid, 1.5 parts of emulsifier, and 34 parts of water.

[0069] Preparation method of silicone resin emulsion: 75 parts of octamethylcyclotetrasiloxane and 0.6 parts of chloroplatinic acid are added to 34 parts of water, and then 1.5 parts of emulsifier are added, heated to 95° C., and stirred stably for 5 hours to obtain silicone resin emulsion.

[0070] (2) Preparation of permanent capsule release agent:

[0071] The permanent capsule release agent includes, by mass, 10 parts of silicone resin emulsion, 30 parts of hydrogenated silicone oil emulsion, 1 part of silica sol, 1 part of fungicide, and 75 parts of water.

[0072] Preparation method of permanent capsule release agent: add 10 parts of silicone resin emulsion in step (1) to 75 parts of water at 95°C and then add 30 parts of hydrogenated silicone oil emulsion, stir for 3 hours, then add 1 part of silica sol, stir for another 2 hours, cool to 45°C, add 1 part of fungicide, and package after passing the test to obtain the permanent capsule release agent.

[0073] Example 3

[0074] (1) Preparation of silicone resin emulsion

[0075] The silicone resin emulsion comprises, by mass, 70 parts of octamethylcyclotetrasiloxane, 0.5 parts of alkylbenzenesulfonic acid, 1.3 parts of emulsifier, and 30 parts of water.

[0076] Preparation method of silicone resin emulsion: add 70 parts of octamethylcyclotetrasiloxane and 0.5 parts of alkylbenzenesulfonic acid to 30 parts of water, then add 1.3 parts of emulsifier, heat to 80°C, and stir stably for 8 hours to obtain silicone resin emulsion.

[0077] (2) Preparation of permanent capsule release agent:

[0078] The permanent capsule release agent comprises, by mass, 8 parts of silicone resin emulsion, 20 parts of hydrogenated silicone oil emulsion, 0.5 parts of silica sol, 0.1 parts of fungicide and 72 parts of water.

[0079] Preparation method of permanent capsule release agent: at 80°C, add 8 parts of silicone resin emulsion in step (1) to 72 parts of water and then add 20 parts of hydrogenated silicone oil emulsion, stir for 4 hours, then add 0.5 parts of silica sol and stir for another 2.5 hours, cool to 40°C, add 0.1 parts of fungicide, and package after passing the test to obtain the permanent capsule release agent.

[0080] Example 4

[0081] (1) Preparation of silicone resin emulsion

[0082] The silicone resin emulsion comprises, by mass, 68 parts of octamethylcyclotetrasiloxane, 0.4 parts of alkylbenzenesulfonic acid, 1.2 parts of emulsifier, and 26 parts of water.

[0083] Preparation method of silicone resin emulsion: add 68 parts of octamethylcyclotetrasiloxane and 0.4 parts of alkylbenzenesulfonic acid to 26 parts of water, then add 1.3 parts of emulsifier, heat to 85°C, and stir stably for 6 hours to obtain silicone resin emulsion.

[0084] (2) Preparation of permanent capsule release agent:

[0085] The permanent capsule release agent comprises, by mass, 6 parts of silicone resin emulsion, 25 parts of hydrogenated silicone oil emulsion, 0.1 part of silica sol, 0.1 part of fungicide, and 74 parts of water.

[0086] Preparation method of permanent capsule release agent: at 90°C, add 6 parts of silicone resin emulsion in step (1) to 74 parts of water and then add 25 parts of hydrogenated silicone oil emulsion, stir for 4 hours, then add 0.1 parts of silica sol and stir for another 2 hours, cool to 37°C, add 0.1 parts of fungicide, and package after passing the test to obtain permanent capsule release agent.

[0087] Comparative Example 1

[0088] The semi-permanent release agent was prepared according to the preparation method of the semi-permanent release agent disclosed in CN109895296A.

[0089] Comparative Example 2

[0090] (1) Preparation of silicone resin emulsion

[0091] The silicone resin emulsion comprises, by mass, 70 parts of octamethylcyclotetrasiloxane, 0.5 parts of alkylbenzenesulfonic acid, 1.3 parts of emulsifier, and 30 parts of water.

[0092] Preparation method of silicone resin emulsion: add 70 parts of octamethylcyclotetrasiloxane and 0.5 parts of alkylbenzenesulfonic acid to 30 parts of water, then add 1.3 parts of emulsifier, heat to 80°C, and stir stably for 8 hours to obtain silicone resin emulsion.

[0093] (2) Preparation of capsule release agent:

[0094] The capsule release agent comprises, by mass, 8 parts of silicone resin emulsion, 20 parts of hydrogenated silicone oil emulsion, 0.1 part of fungicide, and 72 parts of water.

[0095] Preparation method of capsule release agent: add 8 parts of silicone resin emulsion in step (1) to 72 parts of water at 80°C and then add 20 parts of hydrogenated silicone oil emulsion, stir for 4 hours, then stir for another 2.5 hours, cool to 40°C, add 0.1 parts of fungicide, and package after passing the test to obtain capsule release agent.

[0096] Comparative Example 3

[0097] (1) Preparation of silicone resin emulsion

[0098] The silicone resin emulsion comprises, by mass, 70 parts of octamethylcyclotetrasiloxane, 0.5 parts of alkylbenzenesulfonic acid, 1.3 parts of emulsifier, and 30 parts of water.

[0099] Preparation method of silicone resin emulsion: add 70 parts of octamethylcyclotetrasiloxane and 0.5 parts of alkylbenzenesulfonic acid to 30 parts of water, then add 1.3 parts of emulsifier, heat to 80°C, and stir stably for 8 hours to obtain silicone resin emulsion.

[0100] (2) Preparation of capsule release agent:

[0101] The capsule release agent comprises, by mass, 20 parts of silicone resin emulsion, 8 parts of hydrogenated silicone oil emulsion, 0.05 parts of silica sol, 0.1 parts of fungicide and 72 parts of water.

[0102] Preparation method of capsule release agent: at 80°C, add 20 parts of silicone resin emulsion in step (1) to 72 parts of water and then add 8 parts of hydrogenated silicone oil emulsion, stir for 4 hours, then add 0.05 parts of silica sol and stir for another 2.5 hours, cool to 40°C, add 0.1 parts of fungicide, and package after passing the test to obtain capsule release agent.

[0103] Experimental Example 1

[0104] The permanent capsule release agents obtained in Examples 1-4 were recorded as FBP-1, FBP-2, FBP-3, and FBP-4, and the release agents obtained in Comparative Examples 1-3 were recorded as RE-1, RE-2, and RE-3.

[0105] (1) Take 7 groups of capsules (5 capsules per group, the vulcanization results are the average of the 5 capsules) and place them in a 170℃ oven for 5 minutes. Take them out and apply FBP-1, FBP-2, FBP-3, FBP-4, RE-1, RE-2, and RE-3 to each group while they are still hot. Let them stand for 1.5 hours until there is no obvious liquid accumulation on the surface. Then place them in a preheated 170℃ oven and bake for 1 hour, and then vulcanize them.

[0106] (2) Preheat the homemade vulcanization mold in advance, place the capsules baked in step (1) into the lower mold respectively, put the airtight layer glue on the surface of the capsule, and then cover the upper mold. Place it in a flat vulcanizer and vulcanize it at 190°C for 400s. Observe the adhesion between the airtight layer glue and the capsule sheet each time the mold is opened, and the number of vulcanization times when they cannot be separated naturally is used as the demolding result.

[0107] Experimental Example 2

[0108] The permanent capsule release agents obtained in Examples 1-4 were recorded as FBP-1, FBP-2, FBP-3, and FBP-4, and the release agents obtained in Comparative Examples 1-3 were recorded as RE-1, RE-2, and RE-3.

[0109] (1) Take 7 groups of capsules (5 capsules per group, the vulcanization results are the average of the 5 capsules) and place them in a 120℃ oven for 5 minutes. Take them out and apply FBP-1, FBP-2, FBP-3, FBP-4, RE-1, RE-2, and RE-3 to each group while they are still hot. Let them air-dry for 2 hours until there is no obvious liquid accumulation on the surface. Then place them in a preheated 120℃ oven and bake for 2 hours, and then vulcanize them.

[0110] (2) Preheat the homemade vulcanization mold in advance, place the capsules baked in step (1) into the lower mold respectively, put the airtight layer glue on the surface of the capsule, and then cover the upper mold. Place it in a flat vulcanizer and vulcanize it at 190°C for 400s. Observe the adhesion between the airtight layer glue and the capsule every time the mold is opened, and the number of vulcanization times when they cannot be separated naturally is used as the demolding result.

[0111] Experimental Example 3

[0112] The permanent capsule release agents obtained in Examples 1-4 were recorded as FBP-1, FBP-2, FBP-3, and FBP-4, and the release agents obtained in Comparative Examples 1-3 were recorded as RE-1, RE-2, and RE-3.

[0113] (1) Take 7 groups of capsules (5 capsules per group, the vulcanization results are the average of the 5 capsules) and place them in a 230℃ oven for preheating for 5 minutes. Take them out and apply FBP-1, FBP-2, FBP-3, FBP-4, RE-1, RE-2, and RE-3 respectively while they are still hot. Let them stand for 0.5 hours until there is no obvious liquid accumulation on the surface. Then place them in a preheated 230℃ oven and bake for 0.5 hours, and then vulcanize them.

[0114] (2) Preheat the homemade vulcanization mold in advance, place the capsules baked in step (1) into the lower mold respectively, put the airtight layer glue on the surface of the capsule, and then cover the upper mold. Place it in a flat vulcanizer and vulcanize it at 190°C for 400s. Observe the adhesion between the airtight layer glue and the capsule every time the mold is opened, and the number of vulcanization times when they cannot be separated naturally is used as the demolding result.

[0115] Comparative Experimental Example 1

[0116] The permanent capsule release agents obtained in Examples 1-4 were recorded as FBP-1, FBP-2, FBP-3, and FBP-4, and the release agents obtained in Comparative Examples 1-3 were recorded as RE-1, RE-2, and RE-3.

[0117] (1) Take 7 groups of capsules (5 capsules per group, the curing results are the average of the 5 capsules) and coat each group with FBP-1, FBP-2, FBP-3, FBP-4, RE-1, RE-2, and RE-3, respectively. Let them stand for 1.5 hours until there is no obvious liquid accumulation on the surface, and then proceed with curing.

[0118] (2) Preheat the homemade vulcanization mold in advance, place the capsules in step (1) into the lower mold respectively, put the airtight layer glue on the surface of the capsule, and then cover the upper mold. Place it in a flat vulcanizer and vulcanize it at 190℃ for 400s. Observe the adhesion between the airtight layer glue and the capsule every time the mold is opened, and the number of vulcanization times when they cannot be separated naturally is taken as the demolding result.

[0119] The vulcanization demoulding times of Experimental Examples 1-3 and Comparative Example 1 were recorded respectively.

[0120] Table 1 Experimental Example 1 Vulcanization demoulding times results

[0121] Release agent type Vulcanization demoulding results (number of times) FBP-1 312 FBP-2 320 FBP-3 341 FBP-4 325 RE-1 48 RE-2 70 RE-3 110

[0122] Table 2 Experimental Example 2 Vulcanization demoulding times results

[0123] Release agent type Vulcanization demoulding results (number of times) FBP-1 287 FBP-2 314 FBP-3 320 FBP-4 319 RE-1 38 RE-2 65 RE-3 100

[0124] Table 3 Experimental Example 3 Vulcanization demoulding times results

[0125] Release agent type Vulcanization demoulding results (number of times) FBP-1 306 FBP-2 310 FBP-3 328 FBP-4 316 RE-1 42 RE-2 80 RE-3 145

[0126] Table 4 Experimental comparative example 1 vulcanization demoulding times results

[0127]

[0128]

[0129] As shown in the table above, the demolding frequency after a single treatment with a permanent capsule release agent reached over 300, significantly higher than that achieved with a semi-permanent capsule release agent. This demonstrates that the permanent capsule release agent has a significantly superior release agent effect compared to the semi-permanent capsule release agent. Furthermore, oven pretreatment allows for the capsules to be pre-treated, significantly improving production efficiency.

[0130] The above experimental examples 1-3 and comparative example 1 are laboratory vulcanization test results. In the laboratory, a flat vulcanizing machine, a homemade vulcanization mold, and homemade capsule tablets were used to perform vulcanization tests on the release agent release effect.

[0131] Next, vulcanization tests were carried out in the vulcanization workshop of the tire factory. In the vulcanization workshop, hydraulic vulcanizers were used to vulcanize different types of semi-steel radial tires on different machines. The vulcanization time was 12 minutes and the vulcanization temperature was 180°C.

[0132] Treatment method (1) Oven pretreatment

[0133] Place the new capsule in a 170°C oven and preheat for about 5 minutes. Take it out and pretreat it with the permanent capsule isolation agent prepared in Example 1 while it is still hot. Use special gloves for coating capsules to apply the coating. Let it stand for about 1.5 hours until there is no obvious liquid accumulation on the surface of the capsule. Then place it in an oven and bake it at 170°C for 1 hour. Take it out and let it cool to room temperature before installing it for use.

[0134] Processing method (2) Machine processing

[0135] Install a new bladder on the vulcanizer, close the mold and preheat at 170°C for 20 minutes, inflate the bladder to a slightly expanded state, and evenly apply the permanent bladder release agent prepared in Example 1 to the bladder surface using a special glove for bladder coating. After the moisture on the bladder surface evaporates, perform several shaping and stretching operations appropriately before installing the tire and vulcanizing.

[0136] Experimental results (partial data):

[0137] Table 5: Results of curing test of permanent capsule release agent in a tire factory in Shaanxi

[0138]

[0139] As shown in Table 5, in experiments conducted in the tire factory's vulcanization workshop, after oven pretreatment of capsules of various specifications and a single treatment with a permanent capsule release agent, the number of consecutive demoldings approached the average lifespan of the capsules. Furthermore, using direct processing on the machine, capsules of various specifications, after a single treatment with a permanent capsule release agent, achieved over 100 consecutive demoldings. This compares to the semi-permanent capsule release agent currently used in tire factories, which can only achieve 20 consecutive demoldings after a single treatment. This demonstrates that permanent capsule release agents have a significantly superior release agent effect compared to semi-permanent capsule release agents. Furthermore, oven pretreatment allows the capsules to be processed in advance, eliminating the need for machine operation time. This not only increases the number of consecutive demoldings but also significantly improves production efficiency.

[0140] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A permanent capsule release agent, characterized in that: The composition includes, by mass: 8 parts of silicone resin emulsion, 20 parts of hydrogenated silicone oil emulsion, 0.5 parts of silica sol, and 72 parts of water; The steps for using the capsule isolation agent are as follows: S1. Heat the capsule to 120-230°C; S2. Applying a capsule release agent to the surface of the capsule obtained in step S1 and leaving it to air-dry; S3, baking the capsules coated with the capsule release agent obtained in step S2 at 120° C.-230° C.; The air-drying time in step S2 is 0.5-2h; The baking time in step S3 is 0.5-1.5h.

2. A permanent capsule release agent according to claim 1, characterized in that: The usage ratio of the hydrogenated silicone oil emulsion to the silicone resin emulsion is 2.5:

1.

3. A permanent capsule release agent according to claim 1, characterized in that: The silicone resin emulsion comprises, by mass, 65-75 parts of organosilicon monomer, 0.4-0.6 parts of organic acid catalyst, 1-1.5 parts of emulsifier, and 23-34 parts of water.

4. A permanent capsule release agent according to claim 3, characterized in that: The silicone resin emulsion comprises, by mass, 70 parts of organosilicon monomer, 0.5 parts of organic acid catalyst, 1.3 parts of emulsifier, and 30 parts of water.

5. A permanent capsule release agent according to claim 3, characterized in that: The silicone resin emulsion comprises, by mass, 68 parts of organosilicon monomer, 0.4 parts of organic acid catalyst, 1.2 parts of emulsifier, and 26 parts of water.

6. A permanent capsule release agent according to claim 3, characterized in that: The organic acid catalyst is alkylbenzenesulfonic acid or chloroplatinic acid.

7. A permanent capsule release agent according to claim 3, characterized in that: The organosilicon monomer is octamethylcyclotetrasiloxane.

8. A permanent capsule release agent according to claim 1, characterized in that: The permanent capsule isolating agent also includes a bactericide, and the bactericide is 0.01-1 parts by mass.

9. A method for preparing the permanent capsule release agent according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) adding a silicone resin emulsion to water at 70-95° C. to obtain solution A; (2) adding hydrogenated silicone oil emulsion to solution A and stirring for 3-5 hours to obtain solution B; (3) adding silica sol to solution B and stirring for 2-3 hours to obtain solution C; (4) After solution C is cooled, a permanent capsule release agent is obtained.

10. The method for preparing a permanent capsule release agent according to claim 9, characterized in that: In step (1), silicone resin emulsion is added to water at 80°C.

11. The method for preparing a permanent capsule release agent according to claim 9, characterized in that: In step (1), silicone resin emulsion is added to water at 90°C.

12. The method for preparing a permanent capsule release agent according to claim 9, characterized in that: In step (2), solution B was obtained after stirring for 4 hours.

13. The method for preparing a permanent capsule release agent according to claim 9, characterized in that: In step (4), after the solution C is cooled, a bactericide is added to obtain a permanent capsule isolation agent.

14. The method for preparing a permanent capsule release agent according to claim 9, characterized in that: In step (4), solution C is cooled to 35-45°C.

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