Rubber synthetic material for mold cleaning having lubricating effect and method of manufacturing

Abstract

The application discloses a rubber synthetic material with lubricating effect for mold cleaning and a preparation method thereof, and relates to the technical field of rubber preparation for mold cleaning. The support body comprises raw materials such as natural rubber, butyl rubber, precipitated white carbon black and stearic acid; the rubber coating comprises raw materials such as ethylene-propylene rubber, butyl rubber, precipitated white carbon black, silane coupling agent, end hydrogen polydimethylsiloxane, allyl polyethylene glycol and dicumyl peroxide; and the lubricating glue layer comprises raw materials such as natural rubber, butyl rubber, fumed white carbon black, sodium tripolyphosphate, potassium carbonate and cumene peroxide. The method comprises the following steps: preparing the support body by using a mold forming method; preparing the rubber coating in the mold; sleeving the rubber coating on the support body; and pressing the rubber skin on the surface of the rubber coating of the wrapped body while the rubber skin is hot. The support body is internally provided with an air cavity structure, air exhaust and demolding functions are realized, and the problems that air between the rubber and the inner wall of the mold is not easy to exhaust and demolding is difficult in the prior art are effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of rubber preparation technology for mold cleaning, and specifically discloses a synthetic rubber material for mold cleaning with lubricating effect and its preparation method. Background Technology

[0002] With the development of science and technology and industry, the application of rubber products in various fields is becoming increasingly widespread, and market demand continues to grow. In the electronic packaging industry, metal molds and epoxy molding compounds are commonly used for semiconductor chip packaging to achieve industrialized production. However, during repeated injection molding or transfer molding processes, volatile components generated by the heating molding material, exudates from the molded product surface, and release agents used in the molding process can easily adhere to the mold surface. These deposits are prone to oxidation and deterioration at high temperatures, leading to mold contamination. When the mold is contaminated, it not only adversely affects the dimensional accuracy, appearance quality, and release performance of the molded product, but may also cause mold corrosion, reducing production efficiency and increasing maintenance costs.

[0003] Factors such as rough mold surfaces, incomplete cleaning, and insufficient scorching time of the compounded rubber can easily lead to excessively rough surfaces on molded products. Simultaneously, the presence of sulfur-decomposing substances in the compounding agents, inadequate air removal from the mold cavity, and the lack of venting lines in the mold can easily cause air bubble defects on the surface of the product or mold. During demolding, excessive tensile force or insufficient strength of the rubber compound can easily lead to tearing of the demolded product. Furthermore, some existing rubber and plastic processing products exhibit unreasonable structural design and variety configurations, resulting in inconsistent product quality. To meet the requirements of high-temperature, rapid, and efficient rubber processing, highly chemically active materials are often required. These materials may release harmful substances during production, adversely affecting the environment and human health.

[0004] In response to the above situation, it is necessary to develop a high-performance, environmentally friendly mold lubrication and cleaning rubber product. By optimizing its material composition and structure, the surface quality of the product can be improved, molding defects can be reduced, production efficiency can be increased, and the service life of the mold can be extended. This will help improve the overall quality of the product, enhance the competitiveness of enterprises, and meet the ever-growing market demand. Summary of the Invention

[0005] The purpose of this invention is to provide a rubber synthetic material for mold cleaning with lubricating effect and its preparation method. By setting an air cavity in the support body, the gas can be vented and demolded, which solves the problems of gas remaining between the rubber and the inner wall of the mold that cannot be effectively discharged and demolding is difficult.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0007] The present invention is a rubber synthetic material for mold cleaning with lubricating effect, comprising a support body, a rubber sheath and a lubricating layer. The support body has an air cavity, the rubber sheath is hot-pressed over the support body, and the surface of the rubber sheath is hot-pressed with a lubricating layer.

[0008] The support body comprises, by weight, 60-80 parts of natural rubber, 60-80 parts of butyl rubber, 15-20 parts of precipitated silica, 5-10 parts of stearic acid, 10-15 parts of crosslinking agent, and 5-10 parts of silane coupling agent.

[0009] The rubber coating comprises 15-20 parts of ethylene propylene rubber, 15-20 parts of butyl rubber, 3-5 parts of precipitated silica, 2-3 parts of triethanolamine, 3-5 parts of phosphate ester, 3-5 parts of alumina micro powder, 2-3 parts of stearic acid, 1-3 parts of co-crosslinking agent, 2-5 parts of silane coupling agent, 5-10 parts of hydrogen-terminated polydimethylsiloxane, 5-10 parts of allyl polyethylene glycol, and 5-10 parts of dicumyl peroxide;

[0010] The lubricating adhesive layer comprises 1-3 parts natural rubber, 1-3 parts butyl rubber, 0.5-1 parts fumed silica, 0.3-0.5 parts ultrafine talc, 0.3-0.5 parts stearic acid, 0.2-0.4 parts sodium tripolyphosphate, 0.2-0.5 parts potassium carbonate, and 2-3 parts cumene hydrogen peroxide.

[0011] The present invention is further configured such that, after the support body is prepared and shaped, a first array of openings is uniformly processed on the bottom and four side walls using a laser; the rubber sheath is prepared into a box shape and a second array of openings is uniformly processed on the side walls and bottom walls of the rubber sheath; during the manufacturing process, the outer surface of the rubber sheath is hot-pressed into uniformly distributed protrusions; and after the lubricating adhesive layer is melted, it is coated on the outer wall of the rubber sheath and covers the protrusions.

[0012] The diameter of the first opening is 2-3 mm, the diameter of the second opening is 1.0-1.5 mm, the thickness of the rubber coating is 5-8 mm, and the coating thickness of the lubricating adhesive layer is 0.5-1.0 mm.

[0013] The present invention is further configured such that steel strips are uniformly embedded on the bottom and four side walls of the support body, the steel strips having a width of 8-12mm and a length of 25-35mm, and the steel strips 2 having uniformly opened ventilation holes not smaller than the first opening.

[0014] The present invention is further configured such that the Mooney viscosity of the lubricating adhesive layer is 130-170 Mooney, and the Mooney viscosity of the rubber coating layer is 70-120 Mooney.

[0015] A method for preparing a rubber with lubricating properties for mold cleaning, comprising the following steps:

[0016] S1: Weigh 60-80 parts of natural rubber, 60-80 parts of butyl rubber, 15-20 parts of precipitated silica, 5-10 parts of stearic acid, 10-15 parts of crosslinking agent and 5-10 parts of silane coupling agent respectively, and carry out plasticizing, mixing and internal mixing. Then, use a mold forming method to prepare the support body. The support body has an air cavity 12. Then, use a laser hole-opening machine to evenly open the first hole 11 on the bottom and four side walls of the support body.

[0017] S2: Weigh out 15-20 parts of ethylene propylene rubber, 15-20 parts of butyl rubber, 3-5 parts of precipitated silica, 2-3 parts of triethanolamine, 3-5 parts of phosphate ester, 3-5 parts of alumina powder, 2-3 parts of stearic acid, 1-3 parts of crosslinking agent, 2-5 parts of silane coupling agent, 5-10 parts of hydrogen-terminated polydimethylsiloxane, 5-10 parts of allyl polyethylene glycol and 5-10 parts of dicumyl peroxide, and perform plasticizing, mixing and internal mixing. Then, prepare a rubber sheath that can be fitted onto the support body in a mold. The bottom and four side walls of the rubber sheath are uniformly opened with second openings.

[0018] S3: The rubber sheath is placed on the support body, then placed in a hot drying chamber and heated to 70-75℃, then hot-pressed, and then air is introduced into the support body. The gas is discharged from the first opening into the second opening, and then the gas is released outward to form a wrapping body.

[0019] S4: Weigh out 1-3 parts of natural rubber, 1-3 parts of butyl rubber, 0.5-1 parts of fumed silica, 0.3-0.5 parts of ultrafine talc, 0.3-0.5 parts of stearic acid, 0.2-0.4 parts of sodium tripolyphosphate, 0.2-0.5 parts of potassium carbonate, and 2-3 parts of cumene hydrogen peroxide. Plasticize, mix, and internally mix the mixture. Hot press it into a rubber sheet of 0.5-1mm using a roller. Press the hot rubber sheet onto the surface of the rubber coating of the body, and then hot press it for a short time to make the rubber sheet adhere to the surface of the rubber coating.

[0020] The present invention is further configured such that, in step S1, natural rubber and butyl rubber raw materials are first mixed and then subjected to preliminary mixing in a closed rubber mixing mill at 110-130°C for 5.0-10 minutes.

[0021] Add precipitated silica, stearic acid, crosslinking agent and silane coupling agent for preliminary mixing, and mix at 120-135℃ for 5.5-7.0 min;

[0022] The mixing temperature is then increased to 180-200℃ for hot melting. The melted rubber is then poured into a mold, and the support body is prepared using a mold forming method.

[0023] The present invention is further configured such that, in step S2, ethylene propylene rubber and butyl rubber raw materials are first mixed and then subjected to preliminary mixing in a closed rubber mixing mill at 120-140°C for 4.5-6.0 min.

[0024] Precipitated silica, triethanolamine, phosphate ester, alumina powder, stearic acid, crosslinking agent, silane coupling agent, hydrogen-terminated polydimethylsiloxane, and allyl polyethylene glycol are added for preliminary mixing at 125-135℃ for 5.0-7.0 min.

[0025] After mixing, the temperature is lowered to 80-90℃, then dicumyl peroxide is added and mixed for 1.5-2.5 minutes. The raw materials are then poured into a mold and extruded to form a rubber coating.

[0026] The present invention is further configured such that, in step S4, natural rubber and butyl rubber raw materials are first mixed and then subjected to preliminary mixing in a closed rubber mixing mill at 115-125°C for 4.0-6.0 min.

[0027] Add fumed silica, ultrafine talc, stearic acid, sodium tripolyphosphate and potassium carbonate for preliminary mixing, and mix at 125-130℃ for 4.0-6.0 min.

[0028] After mixing, the temperature is lowered to 80-90℃, then cumene hydrogen peroxide is added and mixed for 1.5-2.0 minutes. Then, it is calendered step by step through multiple two-roll calenders to form a thin rubber sheet of 0.5-1.0 mm. Then, while still hot, it is hot-pressed for a short time to make the rubber sheet adhere to the surface of the rubber coating.

[0029] The present invention is further configured such that, after the support body is prepared, steel strips are uniformly embedded in the support body, and the steel strips are uniformly provided with ventilation holes.

[0030] The present invention is further configured such that the thickness of the four side walls and the bottom wall of the air cavity of the supporting body is not less than 20 mm, the thickness of the rubber coating side walls and the bottom wall is 3-5 mm, and the thickness of the lubricating adhesive layer is 0.5-1 mm.

[0031] The present invention has the following beneficial effects:

[0032] 1. After the rubber for mold cleaning is processed and assembled, the cleaning rubber is placed into the mold, and the upper mold presses down to hold the cleaning rubber in place, so that the air cavity is under high pressure. The rubber of the cleaning rubber near the top side wall overflows and tightly adheres to the edge of the mold opening to achieve edge sealing and ensure the internal sealing of the mold. Secondly, the mold pre-vulcanizes the outer wall of the cleaning rubber (lubricating rubber layer). After vulcanization, the lubricating rubber layer has fluidity. The air bubbles remaining between the mold and the lubricating rubber layer will penetrate the lubricating rubber layer, so that the lubricating rubber layer flows and adheres tightly to the inner wall of the mold. The air bubbles will flow back from the second opening (the air pressure inside the support body makes the side wall of the support body exert a high compression on the rubber coating, and the air bubbles achieve reverse flow) and will not accumulate in the side wall of the mold, effectively improving the adhesion of the lubricating rubber layer on the mold wall. In addition, the gaps or scratches in the mold will be filled by the flowing lubricating rubber layer, effectively reducing the air bubbles in the inner wall of the mold, thereby improving the cleaning effect.

[0033] Subsequently, the steel strip is heated using electromagnetic heating (for 15-30 seconds), and the heat from the mold itself is transferred to the rubber coating, achieving rapid heating and vulcanization on both sides. Then, the electromagnetic heating of the steel strip is immediately stopped. At this point, the rubber coating begins to vulcanize and flows and fuses with the lubricating layer. The lubricating layer primarily serves to adhere to the inner wall of the mold, allowing the rubber coating and lubricating layer to flow and bond. During this process, any remaining air bubbles between the two layers flow back towards the support body. The second opening within the rubber coating is gradually compacted and sealed. The air chamber within the air chamber body is appropriately depressurized, and the air bubbles are guided into the air chamber through repeated suction and desorption. The system is then cooled. When the temperature drops to 70-80℃, the rubber essentially loses its fluidity. The upper mold is then lifted and cooled further to room temperature while continued depressurization. This allows the rubber sidewalls used for mold cleaning to detach from the mold sidewalls under negative pressure, thus achieving demolding.

[0034] 2. This invention designs and synthesizes organosilicon compounds containing polar groups such as hydroxyl and amino groups and long-chain aliphatic groups. The hydrophilic hydroxyl and amino groups, as well as the polyethylene glycol branches, can increase the mold-clearing effect, while the long-chain aliphatic groups can increase the compatibility with rubber and regulate the flow properties. Specifically, using hydrogen-containing silicone oil as raw material, under the action of a catalyst, a certain number of active Si-H bonds in the hydrogen-containing silicone oil molecules react successively with functional compounds containing double bonds to obtain epoxy-containing organosilicon intermediates, thereby further improving the mold-clearing ability.

[0035] The above-mentioned beneficial effects are only those that can be achieved by the preferred embodiments. Implementing the present invention does not necessarily mean that all of the above-mentioned beneficial effects will be achieved at the same time. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly described below. Obviously, the drawings described below are only a few embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a process for preparing a lubricating rubber for mold cleaning.

[0038] Figure 2 An exploded view of the rubber structural layer used for mold cleaning.

[0039] Figure 3 A cross-sectional schematic diagram of the rubber structural layer used for mold cleaning.

[0040] Figure 4 A schematic diagram showing the rubber used for cleaning the mold being pressed down inside the mold.

[0041] The attached diagram lists the components represented by each number as follows:

[0042] 1. Support body; 11. First opening; 12. Air cavity; 13. Extruded protruding edge; 2. Steel strip; 3. Rubber coating; 31. Second opening; 4. Lubricating adhesive layer. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please see Figures 1-4 The present invention is a rubber synthetic material for mold cleaning with lubricating effect, comprising a support body 1, a rubber sheath 3 and a lubricating adhesive layer 4. The support body 1 is provided with an air cavity 12. The rubber sheath 3 is hot-pressed to cover the support body 1. The surface of the rubber sheath 3 is hot-pressed with the lubricating adhesive layer 4.

[0045] The support body 1 comprises, by weight, 60-80 parts of natural rubber, 60-80 parts of butyl rubber, 15-20 parts of precipitated silica, 5-10 parts of stearic acid, 10-15 parts of crosslinking agent, and 5-10 parts of silane coupling agent.

[0046] The rubber coating 3 comprises 15-20 parts of ethylene propylene rubber, 15-20 parts of butyl rubber, 3-5 parts of precipitated silica, 2-3 parts of triethanolamine, 3-5 parts of phosphate ester, 3-5 parts of alumina powder, 2-3 parts of stearic acid, 1-3 parts of co-crosslinking agent (trimethylolpropane trimethacrylate), 2-5 parts of silane coupling agent, 5-10 parts of hydrogen-terminated polydimethylsiloxane, 5-10 parts of allyl polyethylene glycol, and 5-10 parts of dicumyl peroxide;

[0047] The lubricating adhesive layer 4 comprises 1-3 parts of natural rubber, 1-3 parts of butyl rubber, 0.5-1 parts of fumed silica, 0.3-0.5 parts of ultrafine talc, 0.3-0.5 parts of stearic acid, 0.2-0.4 parts of sodium tripolyphosphate, 0.2-0.5 parts of potassium carbonate, and 2-3 parts of cumene hydrogen peroxide.

[0048] After the support body 1 is prepared and shaped, the first opening 11 is uniformly processed on the bottom and four side walls by laser. The rubber sheath 3 is prepared into a box shape and the second opening 31 is uniformly opened on the side walls and bottom walls of the rubber sheath 3. During the manufacturing process, the outer surface of the rubber sheath 3 is hot-pressed into uniformly distributed protrusions. After the lubricating adhesive layer 4 is melted, it is coated on the outer wall of the rubber sheath 3 to cover the protrusions.

[0049] Steel strips 2 are evenly embedded on the bottom and four side walls of the support body 1. The width of the steel strips 2 is 8-12mm and the length is 25-35mm. Ventilation holes of not less than the first opening 11 are evenly machined on the steel strips 2.

[0050] Example 1

[0051] A method for preparing a rubber with lubricating properties for mold cleaning, comprising the following steps:

[0052] S1: Weigh out 60 parts of natural rubber, 60 parts of butyl rubber, 15 parts of precipitated silica, 5 parts of stearic acid, 10 parts of crosslinking agent, and 5 parts of silane coupling agent.

[0053] After mixing natural rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 110°C for 5.0 min.

[0054] Precipitated silica, stearic acid, crosslinking agent and silane coupling agent were added for preliminary mixing, and the mixture was mixed at 120°C for 5.5 min.

[0055] The mixing temperature is then increased to 180°C for hot melting. The hot-melted rubber is poured into a mold and the support body 1 is prepared by mold forming method. The support body 1 has an air cavity 12. The first opening 11 is evenly opened on the bottom and four side walls of the support body 1 by laser hole opening machine.

[0056] S2: Weigh out 15 parts of ethylene propylene rubber, 15 parts of butyl rubber, 3 parts of precipitated silica, 2 parts of triethanolamine, 3 parts of phosphate ester, 3 parts of alumina powder, 2 parts of stearic acid, 1 part of crosslinking agent, 2 parts of silane coupling agent, 5 parts of hydrogen-terminated polydimethylsiloxane, 5 parts of allyl polyethylene glycol, and 5 parts of dicumyl peroxide.

[0057] After mixing ethylene propylene rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 120°C for 4.5 minutes.

[0058] Precipitated silica, triethanolamine, phosphate ester, alumina powder, stearic acid, crosslinking agent, silane coupling agent, hydrogen-terminated polydimethylsiloxane and allyl polyethylene glycol were added for preliminary mixing and mixed at 125°C for 5.0 min.

[0059] After mixing, the temperature is lowered to 80°C, then dicumyl peroxide is added and mixed for 1.5 minutes. The raw material is then poured into a mold and extruded to prepare rubber coating 3. Second openings 31 are uniformly opened on the bottom and four side walls of rubber coating 3.

[0060] S3: The rubber sheath 3 is put on the support body 1, then placed in the hot drying chamber and heated to 70°C, then hot-pressed, and then air is introduced into the support body 1. The gas is discharged from the first opening 11 into the second opening 31, and then the gas is released outward to form a wrapping body.

[0061] S4: Weigh out 1 part of natural rubber, 1 part of butyl rubber, 0.5 parts of fumed silica, 0.3 parts of ultrafine talc, 0.3 parts of stearic acid, 0.2 parts of sodium tripolyphosphate, 0.2 parts of potassium carbonate, and 2 parts of cumene hydrogen peroxide, respectively.

[0062] After mixing natural rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 115°C for 4.0 min.

[0063] Add fumed silica, ultrafine talc, stearic acid, sodium tripolyphosphate and potassium carbonate for preliminary mixing, and mix at 125℃ for 4.0 min;

[0064] After mixing, the temperature is lowered to 80℃, then cumene hydrogen peroxide is added and mixed for 1.5 minutes. Then, it is calendered step by step through multiple two-roll calenders to form a 0.5mm thin rubber sheet. Then, while still hot, it is hot-pressed for a short time to make the rubber sheet adhere to the surface of the rubber coating 3.

[0065] After the support body 1 is prepared, steel strips 2 are uniformly embedded in the support body 1, and ventilation holes are uniformly opened on the steel strips 2.

[0066] The air cavity 12 of the support body 1 has a thickness of 20mm on its four side walls and bottom wall, a thickness of 3mm on its rubber sheath side walls and bottom wall, and a thickness of 0.5mm on its lubricating layer.

[0067] Example 2

[0068] A method for preparing a rubber with lubricating properties for mold cleaning, comprising the following steps:

[0069] S1: Weigh out 80 parts of natural rubber, 80 parts of butyl rubber, 20 parts of precipitated silica, 10 parts of stearic acid, 15 parts of crosslinking agent, and 10 parts of silane coupling agent.

[0070] After mixing natural rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 130°C for 10 minutes.

[0071] Precipitated silica, stearic acid, crosslinking agent and silane coupling agent were added for preliminary mixing, and the mixture was mixed at 135°C for 7.0 min.

[0072] The mixing temperature is then increased to 200℃ for hot melting. The hot-melted rubber is poured into a mold and the support body 1 is prepared by mold forming method. The support body 1 has an air cavity 12. The first opening 11 is evenly opened on the bottom and four side walls of the support body 1 by laser hole opening machine.

[0073] S2: Weigh out 20 parts of ethylene propylene rubber, 20 parts of butyl rubber, 5 parts of precipitated silica, 3 parts of triethanolamine, 5 parts of phosphate ester, 5 parts of alumina micro powder, 3 parts of stearic acid, 1-3 parts of crosslinking agent, 5 parts of silane coupling agent, 10 parts of hydrogen-terminated polydimethylsiloxane, 5-10 parts of allyl polyethylene glycol, and 10 parts of dicumyl peroxide.

[0074] After mixing ethylene propylene rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 140°C for 6.0 min.

[0075] Precipitated silica, triethanolamine, phosphate ester, alumina powder, stearic acid, crosslinking agent, silane coupling agent, hydrogen-terminated polydimethylsiloxane and allyl polyethylene glycol were added for preliminary mixing and mixed at 135°C for 7.0 min.

[0076] After mixing, the temperature is lowered to 90°C, then dicumyl peroxide is added and mixed for 2.5 minutes. The raw material is then poured into a mold and extruded to prepare the rubber coating 3. The bottom and four side walls of the rubber coating 3 are uniformly opened with second openings 31.

[0077] S3: The rubber sheath 3 is placed on the support body 1, then placed in the hot drying chamber and heated to 70-75℃, then hot-pressed, and then air is introduced into the support body 1. The gas is discharged from the first opening 11 into the second opening 31, and then the gas is released outward to form a wrapping body.

[0078] S4: Weigh out 3 parts of natural rubber, 3 parts of butyl rubber, 1 part of fumed silica, 0.5 parts of ultrafine talc, 0.5 parts of stearic acid, 0.4 parts of sodium tripolyphosphate, 0.5 parts of potassium carbonate, and 3 parts of cumene hydrogen peroxide.

[0079] After mixing natural rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 125°C for 6.0 min.

[0080] Add fumed silica, ultrafine talc, stearic acid, sodium tripolyphosphate and potassium carbonate for preliminary mixing, and mix at 130℃ for 4.0-6.0 min.

[0081] After mixing, the temperature is lowered to 90℃, then cumene hydrogen peroxide is added and mixed for 2.0 minutes. Then, it is calendered step by step through multiple two-roll calenders to form a 1.0 mm thin rubber sheet. Then, while still hot, it is hot-pressed for a short time to make the rubber sheet adhere to the surface of the rubber sheath 3.

[0082] After the support body 1 is prepared, steel strips 2 are uniformly embedded in the support body 1, and ventilation holes are uniformly opened on the steel strips 2.

[0083] The air cavity 12 of the support body 1 has a thickness of 30mm on its four side walls and bottom wall, a thickness of 5mm on its rubber sheath side walls and bottom wall, and a thickness of 1mm on its lubricating layer.

[0084] Example 3

[0085] A method for preparing a rubber with lubricating properties for mold cleaning, comprising the following steps:

[0086] S1: Weigh out 70 parts of natural rubber, 70 parts of butyl rubber, 18 parts of precipitated silica, 8 parts of stearic acid, 12 parts of crosslinking agent, and 8 parts of silane coupling agent.

[0087] After mixing natural rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 120°C for 7 minutes.

[0088] Precipitated silica, stearic acid, crosslinking agent and silane coupling agent were added for preliminary mixing, and the mixture was mixed at 130°C for 6 minutes.

[0089] The mixing temperature is then increased to 190°C for hot melting. The hot-melted rubber is poured into a mold and the support body 1 is prepared by mold forming method. The support body 1 has an air cavity 12. The first opening 11 is evenly opened on the bottom and four side walls of the support body 1 by laser hole opening machine.

[0090] S2: Weigh out 18 parts of ethylene propylene rubber, 18 parts of butyl rubber, 4 parts of precipitated silica, 2.5 parts of triethanolamine, 4 parts of phosphate ester, 4 parts of alumina powder, 2.5 parts of stearic acid, 2 parts of crosslinking agent, 3 parts of silane coupling agent, 7 parts of hydrogen-terminated polydimethylsiloxane, 7 parts of allyl polyethylene glycol, and 8 parts of dicumyl peroxide.

[0091] After mixing ethylene propylene rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 130°C for 5 minutes.

[0092] Precipitated silica, triethanolamine, phosphate ester, alumina powder, stearic acid, crosslinking agent, silane coupling agent, hydrogen-terminated polydimethylsiloxane and allyl polyethylene glycol were added for preliminary mixing and mixed at 130°C for 6 min.

[0093] After mixing, the temperature is lowered to 85°C, then dicumyl peroxide is added and mixed for 2 minutes. The raw material is then poured into a mold and extruded to prepare rubber coating 3. Second openings 31 are uniformly opened on the bottom and four side walls of rubber coating 3.

[0094] S3: The rubber sheath 3 is put on the support body 1, then placed in the hot drying chamber and heated to 72°C, then hot-pressed, and then air is introduced into the support body 1. The gas is discharged from the first opening 11 into the second opening 31, and then the gas is released outward to form a wrapping body.

[0095] S4: Weigh out 2 parts of natural rubber, 2 parts of butyl rubber, 2 parts of fumed silica, 0.4 parts of ultrafine talc, 0.4 parts of stearic acid, 0.3 parts of sodium tripolyphosphate, 0.4 parts of potassium carbonate, and 2.5 parts of cumene hydrogen peroxide, respectively.

[0096] After mixing natural rubber and butyl rubber raw materials, they are initially mixed in a closed rubber mixing mill and mixed at 120°C for 5 minutes.

[0097] Add fumed silica, ultrafine talc, stearic acid, sodium tripolyphosphate and potassium carbonate for preliminary mixing, and mix at 128℃ for 5 minutes;

[0098] After mixing, the temperature is lowered to 85°C, then cumene hydrogen peroxide is added and mixed for 1.7 minutes. Then, it is calendered step by step through multiple two-roll calenders to form a thin rubber sheet of 0.8 mm. Then, while still hot, it is hot-pressed for a short time to make the rubber sheet adhere to the surface of the rubber sheath 3.

[0099] After the support body 1 is prepared, steel strips 2 are uniformly embedded in the support body 1, and ventilation holes are uniformly opened on the steel strips 2.

[0100] The air cavity 12 of the support body 1 has a thickness of 25mm on its four side walls and bottom wall, a thickness of 4mm on its rubber sheath side walls and bottom wall, and a thickness of 0.8mm on its lubricating layer.

[0101] Examples 1, 2, and 3 are three products made from the same mold, and the mold cleaning operation method is the same.

[0102] The mold cleaning process is as follows:

[0103] The cleaning rubber plug is inserted into the mold, and the upper mold presses down to hold the cleaning rubber in place, creating a high-pressure state inside the air chamber (the support body 1 has inflation and deflation pipes, similar to the air inflator on a tire). Figure 4 In the state of the mold (bottom mold), start heating the mold to 120-130℃. The lubricating rubber layer 4 begins to vulcanize and transfer heat inward. After about 30-60 seconds, the lubricating rubber layer 4 will match and adhere to the inner wall and bottom wall of the mold, squeezing the lubricating rubber layer 4 with air bubbles onto the wall. The air bubbles will penetrate or be forced to migrate into the rubber sheath 3. Since the rubber sheath 3 has a second opening 31, and the air cavity 12 is under high pressure, it pushes the rubber sheath 3 outward. The gas will only permeate in the reverse direction and slowly flow from the second opening 31 into the first opening 11, and then flow into the air cavity 12.

[0104] After the lubricating rubber layer 4 has been vulcanized for 30-60 seconds, the steel strip 2 is briefly heated (electromagnetic heating for 15-30 seconds to bring the temperature of the steel strip 2 to 150℃, at which point it will be cooled by the rubber absorbing heat; or it can be left unheated, in which case it acts as a support to prevent the rubber sheath 3 from flowing extensively into the support body 1). This brief heating ensures that both sides of the rubber sheath 3 are heated, resulting in a faster overall heating rate. Because rubber conducts heat relatively slowly, when the mold heats the rubber sheath 3 to the vulcanization temperature, the side in contact with the support body 1 will begin to vulcanize later. Therefore, brief heating improves the overall vulcanization synchronization of the rubber sheath 3. Then, the heating is immediately stopped to prevent the steel strip 2 from overheating and significantly affecting the support body 1.

[0105] The mold temperature is maintained at 130℃ for 10-20 minutes. Since the support body 1 is at least 20mm thick, and the rubber provides good insulation, the temperature of the support body 1 remains below 100℃, preventing deformation. Furthermore, the sealed air chamber 12 expands after absorbing heat, increasing the pressure on the support body 1. This causes flow and interaction between the rubber coating 3 and the lubricating layer 4, further absorbing air bubbles and better adhering to the mold sidewalls, reducing or eliminating air bubbles on the mold walls (traditional designs without first and second openings cannot effectively guide air bubble flow). Additionally, the air chamber 12 ensures even force distribution across the four walls of the support body 1, unlike traditional rubber strips which are compressed at the top, resulting in uneven force distribution and poor venting.

[0106] After the mold heating is completed, the temperature begins to drop. When it drops to 70-80℃, the rubber coating 3 and the lubricating layer 4 become non-flowable and do not leak air. The air cavity 12 begins to release air (but it is still under high pressure). Then the upper mold is slowly raised and the temperature continues to drop to 40-50℃. The pressure is then completely released, so that the air pressure in the air cavity 12 begins to drop below atmospheric pressure. This causes the support body 1 to be recessed, and the rubber coating 3 and the lubricating layer 4 are pulled away from the mold wall, thus achieving demolding.

[0107] The extruded protrusion 13 position has no first opening 11, which is used to seal the mold opening. During the mold cleaning process, Examples 1, 2 and 3 can adhere to the contaminants on the mold surface within about 20 minutes, and the mold cleaning effect can be achieved after demolding. In some cases, a single cleaning can achieve the cleaning effect, and multiple cleanings can further improve the cleaning effect.

[0108] The lubricating layer 4 is relatively thin. Combined with the function of cumene peroxide, it achieves efficient removal of mold contaminants by rapidly vulcanizing and cross-linking the cleaning adhesive within the mold. When the mold is heated to 120-130℃, the vulcanization temperature of the lubricating layer 4 is around 110℃. Because the vulcanization temperature of the lubricating layer 4 is relatively low (110℃), it is lower than the vulcanization temperature of the rubber sheath 3 (120-130℃). When the temperature of the lubricating layer 4 reaches 130℃, vulcanization continues, but the rubber sheath 3 begins to vulcanize, flowing and penetrating with the lubricating layer 4 to increase its vulcanization temperature. The total thickness of the lubricating layer 4 and the rubber sheath 3 is less than 5mm. It vulcanizes rapidly and flows (slow flow, but deformation due to compression to match the inner wall of the mold). Temperature control and the heat resistance of the rubber are crucial to ensure that the supporting body 1 does not deform significantly.

[0109] Hydrogen-terminated polydimethylsiloxane is a crosslinking aid for silicone rubber-based mold clearing adhesives. It is only applicable to silicone rubber-based mold clearing adhesives and has no significant effect on general-purpose rubber mold clearing adhesives. Its core function is to optimize the adhesion, release properties, and dirt encapsulation ability of the mold clearing adhesive. Hydrogen-terminated polydimethylsiloxane has a flexible molecular chain and low surface energy. When added to silicone rubber mold clearing adhesives (after mixing with lubricating layer 4), it reduces the surface tension of the adhesive, allowing it to quickly wet the tiny gaps, polished surfaces, and dead corners of the mold cavity. It tightly adheres to carbonized residues and mold release agent deposits on the mold surface, significantly improving the ability to encapsulate stubborn dirt and avoiding cleaning blind spots caused by poor adhesive wetting.

[0110] Allyl polyethylene glycol (PEG) molecules contain hydrophilic PEG segments and hydrophobic allyl groups, making them a typical nonionic emulsifying dispersant. The hydrophilic segments can form a weak interface layer between the mold cleaning adhesive and the mold steel surface, reducing the physical adsorption between the adhesive and the metal surface. This significantly reduces the demolding resistance of the vulcanized adhesive strip, making it particularly suitable for cleaning mirror molds and precision electronic molds, preventing scratches on the polished surface of the mold during demolding.

[0111] By utilizing the relatively active Si-H bonds in hydrogen-containing silicone oil molecules (terminated hydrogen polydimethylsiloxane) to react sequentially with functional compounds containing double bonds, an epoxy-containing organosilicon intermediate is obtained.

[0112] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0113] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A rubber synthetic material for mold cleaning with lubricating effect, characterized in that: It includes a support body (1), a rubber sheath (3) and a lubricating layer (4). The support body (1) has an air cavity (12). The rubber sheath (3) is hot-pressed over the support body (1). The surface of the rubber sheath (3) is hot-pressed with a lubricating layer (4). The support body (1) comprises, by weight, 60-80 parts of natural rubber, 60-80 parts of butyl rubber, 15-20 parts of precipitated silica, 5-10 parts of stearic acid, 10-15 parts of crosslinking agent and 5-10 parts of silane coupling agent; The rubber coating (3) comprises, by weight, 15-20 parts of ethylene propylene rubber, 15-20 parts of butyl rubber, 3-5 parts of precipitated silica, 2-3 parts of triethanolamine, 3-5 parts of phosphate ester, 3-5 parts of alumina powder, 2-3 parts of stearic acid, 1-3 parts of crosslinking agent, 2-5 parts of silane coupling agent, 5-10 parts of hydrogen-terminated polydimethylsiloxane, 5-10 parts of allyl polyethylene glycol, and 5-10 parts of dicumyl peroxide; The lubricating adhesive layer (4) comprises, by weight, 1-3 parts of natural rubber, 1-3 parts of butyl rubber, 0.5-1 parts of fumed silica, 0.3-0.5 parts of ultrafine talc, 0.3-0.5 parts of stearic acid, 0.2-0.4 parts of sodium tripolyphosphate, 0.2-0.5 parts of potassium carbonate, and 2-3 parts of cumene hydrogen peroxide; After the support body (1) is prepared and shaped, a first array of openings (11) is uniformly processed on the bottom and four side walls using a laser. The rubber sheath (3) is prepared into a box shape and a second array of openings (31) is uniformly processed on the four side walls and bottom wall of the rubber sheath (3). During the manufacturing process, the outer surface of the rubber sheath (3) is hot-pressed into uniformly distributed protrusions. After the lubricating adhesive layer (4) is melted, it is coated on the outer wall of the rubber sheath (3) to cover the protrusions. The diameter of the first opening (11) is 2-3 mm, the diameter of the second opening (31) is 1.0-1.5 mm, the thickness of the rubber coating (3) is 5-8 mm, and the coating thickness of the lubricating adhesive layer (4) is 0.5-1.0 mm.

2. The rubber synthetic material for mold cleaning with lubricating effect according to claim 1, characterized in that, The support body (1) has steel strips (2) evenly embedded on its bottom and four side walls. The steel strips (2) are 8-12mm wide and 25-35mm long. Ventilation holes no smaller than the first opening (11) are evenly formed on the steel strips (2).

3. The rubber synthetic material for mold cleaning with lubricating effect according to claim 1, characterized in that, The Mooney viscosity of the lubricating adhesive layer (4) is 130-170 Mooney, and the Mooney viscosity of the rubber sheath (3) is 70-120 Mooney.

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