Special high-temperature-resistant silicone rubber for gold stamping wheel and preparation method thereof

Abstract

The invention discloses special high-temperature-resistant silicone rubber for a gold stamping wheel and a preparation method of the special high-temperature-resistant silicone rubber. The silicone rubber is prepared from the following components in parts by mass: 90 to 110 parts of methyl vinyl silicone rubber, 20 to 50 parts of fumed silica, 3 to 9 parts of diphenyl silanediol, 0.5 to 1.0 part of coupling agent, 30 to 60 parts of inorganic filler, 0.1 to 1 part of hydrogen-containing silicone oil, 1 to 10 parts of temperature-resistant additive, 0.05 to 0.5 part of stearic acid and 0.8 to 2 parts of vulcanizing agent. The silicone rubber also comprises 4 to 6 parts of polydimethylsiloxane-hydroxyl and 4 to 6 parts of vinyl silicone resin; 3 to 5 parts of vinyl silicone resin; according to the special high-temperature-resistant silicon rubber for the gold stamping wheel and the preparation method of the special high-temperature-resistant silicon rubber, the silicon rubber with excellent mechanical property and temperature resistance can be prepared, the gold stamping wheel prepared from the silicon rubber can still ensure the temperature resistance, wear resistance and compression-resistant rebound resilience when the gold stamping wheel is in a high-temperature pressed state, and the high-temperature-resistant silicon rubber can still keep the temperature resistance, wear resistance and compression-resistant rebound resilience in a high-temperature environment. The degradation effect and the fatigue resistance of the silicone rubber base material are inhibited.

Description

Technical Field

[0001] The invention specifically relates to a high temperature resistant silicone rubber special for a hot stamping wheel and a preparation method thereof, and belongs to the technical field of high temperature resistant silicone rubber. Background Art

[0002] The hot stamping wheel is a consumable for hot stamping machines, hot presses, edge banding machines, heat transfer machines and laminating machines. It is a consumable product for special printing and can complete the hot stamping, hot silvering and heat transfer process packaging of various products. The existing hot stamping wheel has a temperature resistance of 250~400℃ and a Shore A hardness of 25~90. Since the hot stamping wheel works in high temperature and pressure environments, the hot stamping wheel has a short service life. Therefore, it is necessary to improve the silicone rubber used for processing the hot stamping wheel. The existing silicone rubber, such as China Patent Publication No.: CN117402497A, discloses a long-term high temperature resistant silicone rubber, including the following raw materials: methyl vinyl silicone rubber, fumed silica, diphenylsilanediol, coupling agent, nano-resistant High temperature agent and disulfurizing agent; at the same time, a preparation method of the long-term high temperature resistant rubber is also disclosed. The long-term high temperature resistant silicone rubber prepared by the method has high mechanical strength and long-term high temperature resistance, and can be effectively used for about 30 days under high temperature conditions of 300°C~350°C; for example, the Chinese patent authorization announcement number: CN115746568B discloses a high temperature resistant silicone rubber material and a preparation method thereof, which can maintain the physical properties of silicone rubber to a large extent under the action of high temperature for a long time, and is simple to operate; but when the silicone rubber prepared by the above method is used in a hot stamping wheel, the service life of the hot stamping wheel is still not ideal under the environment of high temperature, pressure and friction. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a high temperature resistant silicone rubber specially used for a hot stamping wheel and a preparation method thereof, which can ensure the service life of the hot stamping wheel under high temperature, pressure and friction environment.

[0004] The high temperature resistant silicone rubber specially used for hot stamping wheels of the present invention comprises the following components in proportion by weight: 90~110 parts of methyl vinyl silicone rubber, 20~50 parts of fumed silica, 3-9 parts of diphenylsilanediol, Coupling agent 0.5~1.0 parts, 30~60 parts of inorganic filler, 0.1~1 part of hydrogen silicone oil, 1~10 parts of heat-resistant additive, Stearic acid 0.05~0.5 parts, Vulcanizing agent 0.8~2 parts, The silicone rubber also includes polydimethylsiloxane-hydroxyl group, and the polydimethylsiloxane-hydroxyl group contains 4 to 6 parts.

[0005] The hydrogen-containing silicone oil produces hydrogen bonds with the silicone rubber molecular chains of methyl vinyl silicone rubber. The cross-linked network formed by hydrogen bonds increases the cross-linking density of the silicone rubber, improves the tear strength, compressive rebound performance and high temperature resistance of the methyl vinyl silicone rubber, and because the polydimethylsiloxane-hydroxyl molecular chain is short, the two silicone rubber molecular chains are connected by hydrogen bonds, which increases the flexibility of the methyl vinyl silicone rubber. The prepared silicone rubber has excellent tear strength and flexibility, thereby ensuring that the prepared hot stamping wheel has excellent fatigue resistance.

[0006] Furthermore, the inorganic filler is one or more of silicon micropowder, diatomaceous earth and quartz powder; the inorganic filler is a nanofiller. Since the inorganic filler is nanoscale, it can be fully dispersed in the methyl vinyl silicone rubber, and can improve the temperature and structural strength of the silicone rubber base material at 5% weight loss (Td, 5%), and at the same time can improve the wear resistance of the silicone rubber.

[0007] Furthermore, the silicone rubber also includes vinyl silicone resin, which is 3 to 5 parts. The vinyl silicone resin can be fully dispersed in the silicone rubber and combined with inorganic fillers to reinforce the silicone rubber. That is, after the silicone resin is added to the silicone rubber, it can also realize the function of a crosslinking agent and realize centralized crosslinking inside the silicone rubber, thereby further improving the overall wear resistance and degradation inhibition performance of the silicone rubber.

[0008] Furthermore, the hydrogen content of the hydrogen-containing silicone oil is 0.5-1.5%; the specific surface area of ​​the fumed silica is 200-280.

[0009] Furthermore, the heat-resistant additive includes the following components by mass percentage: 40% iron oxide, 30% cerium oxide and 30% titanium dioxide. The heat-resistant additive is compounded with high-valent metal ions and low-valent metal ions to achieve the reaction of high-valent metal ions with free radicals generated by thermal oxygen decomposition of silicone rubber to generate R + It can inhibit the thermal oxidation cracking reaction of silicone rubber, and the low-valent metal ions can be oxidized to high-valent states, thereby continuously generating R + .

[0010] Furthermore, the stearic acid is one or more of stearic acid, zinc stearate, calcium stearate or magnesium stearate.

[0011] Furthermore, the vulcanizing agent is peroxide bis(2,4-dichlorobenzoyl peroxide) and / or bis(2,5-dimethyl-2,5-di-tert-butyl peroxide).

[0012] Furthermore, the coupling agent is one or more of silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570 and silane coupling agent KH-580.

[0013] A method for preparing a special high temperature resistant silicone rubber for a hot stamping wheel, which is used to prepare the special high temperature resistant silicone rubber for a hot stamping wheel, and the method is specifically as follows: First, the raw materials are weighed according to the mass ratio of the components, and the methyl vinyl silicone rubber, fumed silica, diphenylsilanediol, coupling agent, inorganic filler, hydrogenated silicone oil and stearic acid in the raw materials are put into an open mill, and the raw materials are mixed by the open mill for 7-8 hours at a mixing temperature of 100-120°C to obtain a primary rubber mix, then, a heat-resistant additive is added to the primary rubber mix, and mixed for 1-2 hours at a mixing temperature of 100-120°C; the mixture is kneaded and mixed into a mass to obtain a secondary rubber mix; then, the secondary rubber mix is ​​added Add vulcanizing agent and mix for 2~3h, the mixing temperature is 100~120℃; then raise the temperature to 140~155℃, continue mixing for 2~3h, and obtain the mixed rubber sheet to be vulcanized; then, perform primary vulcanization on the mixed rubber sheet to be vulcanized, the vulcanization temperature is 180~190℃; the vulcanization time is 30min, and a primary vulcanized rubber sheet is obtained, and then the primary vulcanized rubber sheet is subjected to secondary vulcanization, the vulcanization temperature is 215~220℃; the vulcanization time is 1.5~2h, and after the vulcanization is completed, a finished rubber sheet is obtained.

[0014] Compared with the prior art, the special high-temperature resistant silicone rubber for hot stamping wheels of the present invention and the preparation method thereof can prepare silicone rubber with excellent mechanical properties and temperature resistance. The hot stamping wheel prepared with the silicone rubber can still ensure the heat resistance, wear resistance and compressive resilience when the hot stamping wheel is under high temperature and pressure, thereby ensuring that all parts of the hot stamping wheel are evenly pressurized under high temperature conditions and no rolling defects occur; the hot stamping effect is guaranteed, and the degradation and fatigue resistance of the silicone rubber base material can be suppressed, thereby greatly extending the replacement cycle of the hot stamping wheel. DETAILED DESCRIPTION

[0015] The high temperature resistant silicone rubber specially used for hot stamping wheels of the present invention comprises the following components in proportion by weight: 90~110 parts of methyl vinyl silicone rubber, 20~50 parts of fumed silica, 3-9 parts of diphenylsilanediol, Coupling agent 0.5~1.0 parts, 30~60 parts of inorganic filler, 0.1~1 part of hydrogen silicone oil, 1~10 parts of heat-resistant additive, Stearic acid 0.05~0.5 parts, Vulcanizing agent 0.8~2 parts, The silicone rubber also includes polydimethylsiloxane-hydroxyl group, and the polydimethylsiloxane-hydroxyl group contains 4 to 6 parts.

[0016] The hydrogen-containing silicone oil produces hydrogen bonds with the silicone rubber molecular chains of methyl vinyl silicone rubber. The cross-linked network formed by hydrogen bonds increases the cross-linking density of the silicone rubber, improves the tear strength, compressive rebound performance and high temperature resistance of the methyl vinyl silicone rubber, and because the polydimethylsiloxane-hydroxyl molecular chain is short, the two silicone rubber molecular chains are connected by hydrogen bonds, which increases the flexibility of the methyl vinyl silicone rubber. The prepared silicone rubber has excellent tear strength and flexibility, thereby ensuring that the prepared hot stamping wheel has excellent fatigue resistance.

[0017] The inorganic filler is one or more of silicon micropowder, diatomaceous earth and quartz powder; the inorganic filler is a nanofiller. Since the inorganic filler is nanoscale, it can be fully dispersed in the methyl vinyl silicone rubber, and can improve the temperature and structural strength of the silicone rubber base material at 5% weight loss (Td, 5%), and at the same time can improve the wear resistance of the silicone rubber.

[0018] The silicone rubber also includes vinyl silicone resin, which contains 3 to 5 parts of vinyl silicone resin. The vinyl silicone resin can be fully dispersed in the silicone rubber and combined with inorganic fillers to reinforce the silicone rubber. That is, after the silicone resin is added to the silicone rubber, it can also realize the function of a crosslinking agent and realize centralized crosslinking inside the silicone rubber, thereby further improving the overall wear resistance and degradation inhibition performance of the silicone rubber.

[0019] The hydrogen content of the hydrogen-containing silicone oil is 0.5-1.5%; the specific surface area of ​​the fumed silica is 200-280.

[0020] The heat-resistant additive includes the following components by mass percentage: 40% iron oxide, 30% cerium oxide and 30% titanium dioxide. The heat-resistant additive is compounded with high-valent metal ions and low-valent metal ions to achieve the reaction of high-valent metal ions with free radicals generated by thermal oxygen decomposition of silicone rubber to generate R + It can inhibit the thermal oxidation cracking reaction of silicone rubber, and the low-valent metal ions can be oxidized to high-valent states, thereby continuously generating R + .

[0021] The stearic acid is one or more of stearic acid, zinc stearate, calcium stearate or magnesium stearate.

[0022] The vulcanizing agent is peroxide bis(2,4-dichlorobenzoyl peroxide) and / or bis(2,5-dimethyl-2,5-di-tert-butyl peroxide hexane.

[0023] The coupling agent is one or more of silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570 and silane coupling agent KH-580.

[0024] A method for preparing a special high temperature resistant silicone rubber for a hot stamping wheel, which is used to prepare the special high temperature resistant silicone rubber for a hot stamping wheel, and the method is specifically as follows: First, the raw materials are weighed according to the mass ratio of the components, and the methyl vinyl silicone rubber, fumed silica, diphenylsilanediol, coupling agent, inorganic filler, hydrogenated silicone oil and stearic acid in the raw materials are put into an open mill, and the raw materials are mixed by the open mill for 7-8 hours at a mixing temperature of 100-120°C to obtain a primary rubber mix, then, a heat-resistant additive is added to the primary rubber mix, and mixed for 1-2 hours at a mixing temperature of 100-120°C; the mixture is kneaded and mixed into a mass to obtain a secondary rubber mix; then, the secondary rubber mix is ​​added Add vulcanizing agent and mix for 2~3h, the mixing temperature is 100~120℃; then raise the temperature to 140~155℃, continue mixing for 2~3h, and obtain the mixed rubber sheet to be vulcanized; then, perform primary vulcanization on the mixed rubber sheet to be vulcanized, the vulcanization temperature is 180~190℃; the vulcanization time is 30min, and a primary vulcanized rubber sheet is obtained, and then the primary vulcanized rubber sheet is subjected to secondary vulcanization, the vulcanization temperature is 215~220℃; the vulcanization time is 1.5~2h, and after the vulcanization is completed, a finished rubber sheet is obtained.

[0025] First, before the trial production of silicone rubber, the various components of the components are compounded. During the experiment, methyl vinyl silicone rubber, fumed silica (specific surface area 280) and diphenylsilanediol are used as the basic formula to obtain blank silicone rubber, and a variable component is added to the basic formula, such as one of inorganic fillers, stearic acid, vulcanizers and coupling agents; through experimental testing, one component in each group of variable components and multiple components are compounded to obtain multiple groups of variable test objects, or by adjusting the content ratio of each group of variable components to obtain multiple groups of variable test objects; the experiment selects the test pieces with the best high temperature resistance, mechanical properties and wear resistance; the component ratios selected for the test are as follows: 1. Optimal inorganic filler: Silica powder, diatomaceous earth and quartz powder are in a weight ratio of 2:1:2; 2. Optimal hydrogen-containing silicone oil: The hydrogen content of hydrogen-containing silicone oil is 0.97%; 3. The best option for stearic acid: stearic acid (the difference in experimental performance between the single component and the compound component is negligible, so the single component is directly selected); 4. The best curing agent: dipentadienyl (2,5-dimethyl-2,5-di-tert-butyl peroxyhexane; 5. Optimal coupling agent: Silane coupling agent KH-560 and silane coupling agent KH-580 are used in a weight ratio of 1:2.

[0026] After obtaining the optimal items of the components and contents of the above components, a special high temperature resistant silicone rubber matching experiment for hot stamping wheels is conducted. The special high temperature resistant silicone rubber matching ratio embodiment of the present invention is shown in Table 1: Table 1: List of Examples

[0027] Next, a comparative example was performed. During the experiment, Example 3 was used as a benchmark, and a comparative example was obtained by adjusting a component variable in Example 3. The specific comparative example is shown in Table 2: Table 2: Comparative Examples

[0028] After completing the grouping of the high temperature resistant silicone rubber components for the hot stamping wheel, the silicone rubber sample preparation is carried out; the details are as follows: First, raw materials were weighed according to the component proportions of Examples 1 to 6 and Comparative Examples 1 to 6 to obtain 12 groups of silicone rubber raw materials, and then one group of the 12 groups of raw materials was put into the processing and production of silicone rubber in turn, specifically as follows: methyl vinyl silicone rubber, fumed silica, diphenylsilanediol, coupling agent, inorganic filler, hydrogen-containing silicone oil and stearic acid in the raw materials were put into an open mill, and the raw materials were mixed by the open mill for 7 hours at a mixing temperature of 110°C to obtain a primary rubber mix, and then a heat-resistant additive was added to the primary rubber mix, and mixed for 1.5 hours at a mixing temperature of 120°C; kneaded and mixed into a mass to obtain a secondary rubber mix; then, A vulcanizing agent was added to the secondary mixed rubber and mixed for 2 hours at a mixing temperature of 120°C; then the temperature was raised to 155°C and the mixing was continued for 2-3 hours to obtain a mixed rubber sheet to be vulcanized; then, the mixed rubber sheet to be vulcanized was subjected to a primary vulcanization at a vulcanization temperature of 180°C; the vulcanization time was 30 minutes to obtain a primary vulcanized rubber sheet, and then the primary vulcanized rubber sheet was subjected to a secondary vulcanization at a vulcanization temperature of 220°C; the vulcanization time was 2 hours, and after the vulcanization was completed, a silicone rubber sample was obtained; according to the above process, the remaining 11 groups of silicone rubber raw materials were processed to obtain 11 silicone rubber samples; then, the 12 silicone rubber samples were tested, and the test process was as follows: (1) Tensile test: The tensile properties of the samples were tested using an electronic tensile testing machine in accordance with GB / T528-2009 standard at a rate of 500 mm / min; (2) Tear test: The tearing performance of the sample was tested according to GB / T529-2008 standard at a rate of 500 mm / min; (3) Hardness test: Use Shore A hardness tester to test the hardness of the sample according to GB / T531.2-2009 standard; (4) Impact rebound test: Test the impact rebound of the sample in accordance with GB / T1681-2009 standard; (5) Thermal gravimetric test: using a thermogravimetric analyzer; (5) Wear resistance test: Refer to GB / T9867-2008 "Determination of wear resistance of vulcanized rubber or thermoplastic rubber (rotating roller abrader method)" to test the relative volume wear.

[0029] The test results are shown in Table 3: Table 3 is the performance test results of silicone rubber samples

[0030] It can be seen from the above that the initial decomposition temperature of the silicone rubber prepared in the above embodiments 1 to 6 is 437°C~456°C; in the thermal durability test, at 450°C, the time required for 5% mass loss is 7.7~8.2d, and as the temperature decreases, the time required increases exponentially, indicating that the prepared silicone rubber material has strong thermal stability, excellent heat resistance and thermal durability; and the mechanical properties of the silicone rubber prepared in the above embodiments 1 to 6 are tensile strength of 7.3~7.8MPa, elongation at break of 291~333%, tear strength of 19.1~21.1N / mm, and rebound rate of 61~79%; It can be seen from the above that the silicone rubber prepared in embodiments 1 to 6 has excellent tear strength, compressive resilience, tear strength, flexibility and fatigue resistance, and the pressure on each part of the hot stamping wheel prepared by the silicone rubber is average, and there will be no rolling defects, which greatly extends the replacement cycle of the hot stamping wheel; In addition, it can be seen from the above that the silicone rubber prepared in embodiments 1 to 6 The wear resistance of the rubber is 127~136, which has good wear resistance and can meet the requirements of rolling wear resistance under pressure; in addition, it can be seen from the silicone rubber prepared by the above-mentioned Comparative Examples 1 to 3 that the polydimethylsiloxane-hydroxy component has a positive effect on promoting thermal durability and initial decomposition temperature, and can cooperate with other components to improve the mechanical properties of silicone rubber and enhance the mechanical properties of silicone rubber; it has little effect on wear resistance; the vinyl silicone resin component itself or synergistically acts with other components to promote the thermal durability and initial decomposition temperature of silicone rubber, and can promote the rebound rate and tensile strength of silicone rubber; and can synergize with other components to improve the wear resistance of silicone rubber; hydrogen-containing silicone oil itself or synergistically acts with other components to promote the mechanical properties of silicone rubber; the inorganic filler component itself or synergistically acts with other components to promote the thermal durability and initial decomposition temperature of silicone rubber, and the effect of improving the mechanical properties of silicone rubber is not obvious; and it can improve the wear resistance of silicone rubber.

[0031] The above embodiments are only preferred implementations of the present invention, so any equivalent changes or modifications made according to the structures, features and principles described in the scope of application of the present invention are included in the scope of application of the present invention.

Claims

1. A high temperature resistant silicone rubber for hot stamping wheels, characterized in that: The silicone rubber comprises the following components in proportion by weight: 90~110 parts of methyl vinyl silicone rubber, 20~50 parts of fumed silica, 3-9 parts of diphenylsilanediol, Coupling agent 0.5~1.0 parts, 30~60 parts of inorganic filler, 0.1~1 part of hydrogen silicone oil, 1~10 parts of heat-resistant additive, Stearic acid 0.05~0.5 parts, Vulcanizing agent 0.8~2 parts.

2. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The silicone rubber also includes polydimethylsiloxane-hydroxyl group, and the polydimethylsiloxane-hydroxyl group contains 4 to 6 parts.

3. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The silicone rubber also includes vinyl silicone resin, which contains 3 to 5 parts of vinyl silicone resin.

4. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The inorganic filler is one or more of silicon micropowder, diatomaceous earth and quartz powder; the inorganic filler is a nano filler.

5. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The hydrogen content of the hydrogen-containing silicone oil is 0.5-1.5%; the specific surface area of ​​the fumed silica is 200-280; the heat-resistant additive includes the following components in percentage by weight: 40% iron oxide, 30% cerium oxide and 30% titanium dioxide.

6. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The stearic acid is one or more of stearic acid, zinc stearate, calcium stearate or magnesium stearate.

7. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The vulcanizing agent is peroxide bis(2,4-dichlorobenzoyl peroxide) and / or bis(2,5-dimethyl-2,5-di-tert-butyl peroxide hexane.

8. The high temperature resistant silicone rubber for hot stamping wheels according to claim 1, characterized in that: The coupling agent is one or more of silane coupling agent KH-550, silane coupling agent KH-560, silane coupling agent KH-570 and silane coupling agent KH-580.

9. A method for preparing a special high temperature resistant silicone rubber for a hot stamping wheel, used for preparing the special high temperature resistant silicone rubber for a hot stamping wheel as claimed in any one of claims 1 to 8, characterized in that: The method is specifically as follows: First, the raw materials are weighed according to the mass ratio of the components, and the methyl vinyl silicone rubber, fumed silica, diphenylsilanediol, coupling agent, inorganic filler, hydrogenated silicone oil and stearic acid in the raw materials are put into an open mill, and the raw materials are mixed by the open mill for 7-8 hours at a mixing temperature of 100-120°C to obtain a primary rubber mix, then, a heat-resistant additive is added to the primary rubber mix, and mixed for 1-2 hours at a mixing temperature of 100-120°C; the mixture is kneaded and mixed into a mass to obtain a secondary rubber mix; then, the secondary rubber mix is ​​added Add vulcanizing agent and mix for 2~3h, the mixing temperature is 100~120℃; then raise the temperature to 140~155℃, continue mixing for 2~3h, and obtain the mixed rubber sheet to be vulcanized; then, perform primary vulcanization on the mixed rubber sheet to be vulcanized, the vulcanization temperature is 180~190℃; the vulcanization time is 30min, and a primary vulcanized rubber sheet is obtained, and then the primary vulcanized rubber sheet is subjected to secondary vulcanization, the vulcanization temperature is 215~220℃; the vulcanization time is 1.5~2h, and after the vulcanization is completed, a finished rubber sheet is obtained.

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