CN106928601A - A kind of light aging resisting fluorubber composite and its preparation method and application - Google Patents

Abstract

The invention discloses a photoaging-resistant fluororubber composite material, a preparation method and an application thereof, and belongs to the field of laser components. The photoaging-resistant fluororubber composite material is prepared from the following components by mass: 100 parts of perfluoroether raw rubber, 3-5 parts of _SiO2 hollow spheres with a particle size of 100nm-2 μm, 2.5-3 parts of vulcanizing agent, and 2-2 parts of paraffin wax 3 parts, light stabilizer 0.2‑0.4 parts. The anti-aging fluororubber composite material provided by the present invention utilizes the characteristics of small gas thermal conductivity, and by adding _SiO2 hollow spheres, the volume of gas in the fluororubber composite material is increased, thereby reducing the thermal conductivity of the fluororubber composite material and improving its thermal conductivity. Resistance, so that the fluororubber composite material has good heat insulation performance, prolong the light aging time of components made of fluororubber composite material, and ensure the reliability of other components around.

Description

A kind of anti-aging fluorine rubber composite material and its preparation method and application

technical field

The invention relates to the field of laser components, in particular to a light aging-resistant fluororubber composite material and its preparation method and application.

Background technique

Perfluoroether rubber is composed of tetrafluoroethylene, perfluoroalkyl vinyl ether, and a small amount of third monomer with vulcanization point (for example, CF ₂ = CFOR _f X (X is -COOR, -CN, -OC ₆ F ₅ , etc. )) copolymerized. There are only carbon and fluorine atoms in the main chain of the perfluoroether rubber polymer, and no hydrogen atoms. Due to the large bond energy of the CF bond (485kJ/mol), and the covalent radius of the fluorine atom is 0.064nm, which is close to half the length of the CC bond. , so the fluorine atoms can be closely arranged around the carbon atoms, shielding the CC main chain well, ensuring the stability of the CC main chain, so that perfluoroether rubber has excellent high temperature resistance, weather resistance and oxidation resistance , oil resistance and corrosion resistance, it has been widely used in aerospace, aviation, automobile, petroleum and household appliances and other fields. Specifically, perfluoroether rubber is generally used to make partitions and gaskets in precision instruments to play the role of sealing and isolation.

The inventor finds that the prior art has at least the following technical problems:

The thermal resistance of perfluoroether rubber is relatively small, resulting in poor thermal insulation. Components made of perfluoroether rubber will affect the reliability of other surrounding components when they are heated by light and other effects.

Contents of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a fluororubber composite material with good heat insulation effect and excellent light aging resistance and its preparation method and application. The specific technical scheme is as follows:

In the first aspect, the embodiment of the present invention provides a light-aging resistant fluororubber composite material, which is prepared by using the following components by mass: 100 parts perfluoroether raw rubber, particle size 100nm-2μm 3-5 parts of _SiO2 hollow spheres, 2.5-3 parts of vulcanizing agent, 2-3 parts of paraffin wax, and 0.2-0.4 parts of light stabilizer.

Specifically, preferably, the vulcanizing agent includes the following components in parts by mass: 2-2.3 parts of bisphenol AF, and 0.5-0.7 parts of benzyltriphenylphosphine chloride.

Specifically, preferably, the light stabilizer is a hindered amine light stabilizer.

In the second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned light-resistant aging fluororubber composite material, comprising the following steps:

Pour the perfluoroether raw rubber into the open mill, after Botong plasticizing for 8-15min, add _SiO2 hollow balls, paraffin, light stabilizer, knead for 15-20min, then add vulcanizing agent, at 155～165℃ Perform one-stage vulcanization at 230-290° C. for 28-35 hours under the protection of nitrogen or inert gas to obtain the light-resistant aging fluororubber composite material.

Specifically, as a preference, the _SiO2 hollow spheres are prepared by the following method:

Step a, preparation of melamine formaldehyde microspheres

Prepare a formaldehyde solution with a concentration of 0.0139-0.0278g/ml, add melamine in a water bath at 70-80°C, and then add formic acid, continue stirring for 20-50 minutes after the reaction solution is cloudy, wash and dry the reaction product to obtain the Melamine formaldehyde microspheres.

Wherein, the molar ratio of the formaldehyde to the melamine is 4.5-9:1.

Step b, prepare SiO ₂ and melamine formaldehyde composite microsphere

Use the melamine-formaldehyde microspheres to prepare a melamine-formaldehyde aqueous solution with a mass fraction of 3%-5%, then take 1 volume part of the melamine-formaldehyde aqueous solution, add 13-18 volume parts of pure water and 45-55 volume parts isopropanol, adjust the pH to 7-8, add tetraethyl orthosilicate and stir for 4-5 hours, then filter and dry the product to obtain the composite microspheres of SiO ₂ and melamine formaldehyde.

Step c, preparing SiO ₂ hollow spheres

Calcining the SiO ₂ and melamine formaldehyde composite microspheres at 500-510° C. for 4-5 hours to obtain the SiO ₂ hollow spheres.

In a third aspect, an embodiment of the present invention provides an application of the above-mentioned photoaging-resistant fluororubber composite material in a digital light processing technology laser projection device.

Specifically, as a preference, the spacer is made of the light aging-resistant fluororubber composite material, and the spacer is sleeved on the light pipe along the length direction and placed in the metal bracket of the light pipe as a whole.

Specifically, preferably, the shielding spacer is made of the light aging-resistant fluororubber composite material, and the shielding spacer covers the epoxy resin on the digital micromirror element.

Specifically, as a preference, the rubber baffle is made of the light aging-resistant fluororubber composite material, which is used to replace the metal baffle on the laser vibrating mirror bracket.

Specifically, as a preference, the light-aging resistant fluororubber composite material is used to make a thermal insulation gasket, which is covered on the housing of the laser projection device irradiated by the light in the off state to block the light.

The beneficial effects brought by the technical solution provided by the embodiments of the present invention are:

The photoaging-resistant fluororubber composite material provided by the embodiments of the present invention utilizes the characteristics that the thermal conductivity of the gas is small, and by adding _SiO2 hollow spheres, the volume of the gas in the fluororubber composite material is increased, thereby reducing the thermal conductivity of the fluororubber composite material and improving the thermal conductivity of the fluororubber composite material. Its thermal resistance makes the fluororubber composite material have good heat insulation performance, prolongs the light resistance aging time of components made of fluororubber composite material, and ensures the reliability of other surrounding components. At the same time, the particle size of the _SiO2 hollow spheres is limited to 100nm-2μm, so that _SiO2 hollow spheres with different particle sizes can be interspersed and arranged, so that the gaps between the _SiO2 hollow spheres with larger particle sizes can be filled by smaller particle sizes. SiO ₂ hollow spheres are filled, so that the SiO ₂ hollow spheres are more evenly distributed in the fluororubber composite material, and the gas volume in the fluororubber composite material is greatly increased, so that the fluororubber composite material has more excellent light aging resistance. It can be seen that the light-aging resistant fluororubber composite material provided by the embodiment of the present invention has a good heat insulation effect and excellent light-aging resistance through the synergistic effect between the components, and is easy to use and suitable for large-scale promotion and application.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is a schematic diagram of the application process of the isolation frame provided by the embodiment of the present invention;

Fig. 2 is a schematic diagram of the application process of the shielding partition provided by the embodiment of the present invention;

Fig. 3 is a schematic diagram of the application process of the rubber baffle provided by the embodiment of the present invention;

Figure 4-1 is a schematic diagram of the application scenario of the heat insulation gasket provided by the embodiment of the present invention;

Fig. 4-2 is a schematic diagram of an application scenario of a thermal insulation gasket provided by an embodiment of the present invention.

The reference signs represent respectively:

1 light guide,

2 light guide metal brackets,

3 spacers,

4 DMDs,

5 epoxy resin,

6 shielding partitions,

7 laser galvanometer bracket,

8 rubber stop,

9 off light,

10 housing,

11 Insulation spacer.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the implementation manners of the present invention will be further described in detail below.

In the first aspect, the embodiment of the present invention provides a light aging resistant fluororubber composite material, the light aging resistant fluororubber composite material includes the following components in parts by mass: 100 parts perfluoroether raw rubber, _SiO2 with a particle size of 100nm-2μm 3-5 parts of hollow ball, 2.5-3 parts of vulcanizing agent, 2-3 parts of paraffin, 0.2-0.4 parts of light stabilizer.

The photoaging-resistant fluororubber composite material provided by the embodiments of the present invention utilizes the characteristics that the thermal conductivity of the gas is small, and by adding _SiO2 hollow spheres, the volume of the gas in the fluororubber composite material is increased, thereby reducing the thermal conductivity of the fluororubber composite material and improving the thermal conductivity of the fluororubber composite material. Its thermal resistance makes the fluororubber composite material have good heat insulation performance, prolongs the light resistance aging time of components made of fluororubber composite material, and ensures the reliability of other surrounding components. At the same time, the particle size of the _SiO2 hollow spheres is limited to 100nm-2μm, so that _SiO2 hollow spheres with different particle sizes can be interspersed and arranged, so that the gaps between the _SiO2 hollow spheres with larger particle sizes can be filled by smaller particle sizes. SiO ₂ hollow spheres are filled, so that the SiO ₂ hollow spheres are more evenly distributed in the fluororubber composite material, and the gas volume in the fluororubber composite material is greatly increased, so that the fluororubber composite material has more excellent light aging resistance. It can be seen that the light-aging resistant fluororubber composite material provided by the embodiment of the present invention has a good heat insulation effect and excellent light-aging resistance through the synergistic effect between the components, and is easy to use and suitable for large-scale promotion and application.

Specifically, the perfluoroether raw rubber in the light-resistant aging fluororubber composite material refers to unvulcanized perfluoroether rubber, so that the perfluoroether rubber can be modified. The particle size of SiO ₂ hollow spheres is 100nm-2μm, and the number of various particle sizes is distributed according to statistical laws, so that SiO ₂ hollow spheres of different sizes can be interspersed and arranged to fill the gaps with each other, and the fluororubber composite material can be increased as much as possible. The uniformity of the number and distribution of _SiO2 hollow spheres in the fluorine rubber composite material has a low thermal conductivity and high thermal resistance, and improves its thermal insulation performance and light aging resistance.

The vulcanizing agent is used to cross-link the molecules in the fluororubber composite material to form a network structure, thereby improving the strength of the fluororubber composite material. Specifically, the vulcanizing agent includes the following components in parts by mass: 2-2.3 parts of bisphenol AF, and 0.5-0.7 parts of benzyltriphenylphosphine chloride. Bisphenol AF, also known as 2,2-bis-(4-hydroxyphenyl)hexafluoropropane, is a vulcanizing agent often used in conjunction with benzyltriphenylphosphine chloride for the vulcanization process of fluororubber composite materials .

Light stabilizers can inhibit the degradation of polymers, slow down the discoloration, brittleness, and performance degradation of rubber products, and prolong the light-resistant aging time of rubber products. Therefore, a light stabilizer is selected for the light-aging resistant fluororubber composite material provided in the embodiment of the present invention, and the light stabilizer is preferably a high-quality and efficient hindered amine light stabilizer. The hindered amine light stabilizer has low cost and low toxicity, good compatibility with most polymers, and the light stabilizing effect is better than other types of ultraviolet absorbers. Specifically, the hindered amine light stabilizer can preferably be light stabilizer 944 (CAS No.: 70624-18-9; 71878-19-8), light stabilizer 783 (CAS No.: 70198-29-7), light stabilizer Agent 791 (CAS No.: 71878-19-8/70624-18-9), etc.

In the second aspect, the embodiment of the present invention provides a method for preparing the above-mentioned light aging-resistant fluororubber composite material, which specifically includes the following steps:

Pour the perfluoroether raw rubber into the open mill, after Botong plasticizing for 8-15min, add _SiO2 hollow balls, paraffin, light stabilizer, knead for 15-20min, then add vulcanizing agent, at 155～165℃ Perform one-stage vulcanization at 230-290°C for 28-35 hours under the protection of nitrogen or inert gas to obtain a light-resistant aging fluororubber composite material.

According to the ratio of each raw material in the light-resistant aging fluororubber composite material in the first aspect, according to the above method in sequence, the raw materials are added into the open mill to prepare the light aging resistant fluororubber composite material. The roller distance of the open mill is set at 0.1-0.3mm to enter the thin pass process. Due to the high molecular weight and high viscosity of raw rubber, it is not conducive to mixing with other components. Therefore, it is necessary to squeeze and shear the glue solution through the roller on the open mill, so as to cut off the molecular chain of the raw rubber and improve the quality of the glue solution. fluidity and enhance the plasticity of raw rubber. At the same time, the smaller the distance between the rollers on the mill (that is, the roller distance), the stronger the shearing force on the raw rubber. By setting the roller distance as above, such as 0.1mm, 0.2mm, 0.3mm, etc., and carrying out 8-15min of thin pass plasticizing, such as 8min, 10min, 12min, 15min, etc., you can get suitable for the reaction. Perfluoroelastomer.

After the plasticizing of perfluoroether raw rubber Botong is completed, add SiO ₂ hollow spheres, paraffin wax, and light stabilizer in sequence, and knead for 15-20 minutes, such as 15 minutes, 18 minutes, 20 minutes, etc. Mix evenly in the mill, so that the properties of the rubber produced are uniform and stable.

Then, a two-stage vulcanization process is carried out to obtain a light aging resistant fluororubber composite material. The temperature of one-stage vulcanization is 155°C-165°C, such as 155°C, 158°C, 160°C, 162°C, 165°C, etc., and the vulcanization time is 15-20min, such as 15min, 16min, 17min, 18min, 20min, etc. Preliminary vulcanization and setting of fluororubber composite materials was carried out by one-stage vulcanization. Then carry out two-stage vulcanization under the protection of nitrogen or other inert gases (such as helium, argon, etc.). , The vulcanization time is 28-35h, such as 28h, 30h, 33h, 35h, etc. Through the two-stage vulcanization, the vulcanization of the fluororubber composite material is more thorough, impurities are removed, and the degree of crosslinking between molecules is improved, so that the obtained fluororubber composite material has more stable physical and chemical properties.

The _SiO2 hollow spheres required in the preparation process can be prepared by the following method:

Step 101, preparing melamine-formaldehyde (Melamine-Formaldehyde, MF) microspheres

Prepare a formaldehyde solution with a concentration of 0.0139-0.0278g/ml, add melamine in a water bath at 70-80°C, then add formic acid, and continue stirring for 20-50 minutes after the reaction solution is cloudy, wash and dry the reaction product to obtain melamine formaldehyde Microspheres.

Wherein, the molar ratio of formaldehyde and melamine is 4.5-9:1.

Step 102, preparing SiO ₂ and melamine-formaldehyde composite microspheres

Use melamine-formaldehyde microsphere powder to prepare a melamine-formaldehyde aqueous solution with a mass fraction of 3-5%, then take 1 volume part of the melamine-formaldehyde aqueous solution, add 13-18 volume parts of pure water and 45-55 volume parts of isopropyl Alcohol, adjust the pH to 7-8, add tetraethyl orthosilicate and stir for 4-5 hours, then filter and dry the product to obtain SiO ₂ and melamine-formaldehyde composite microspheres.

Step 103, preparing _SiO2 hollow spheres

Put SiO ₂ and melamine formaldehyde composite microspheres into a muffle furnace at 500-510°C for calcination for 4-5h to obtain SiO ₂ hollow spheres.

Specifically, in step 101, melamine-formaldehyde microspheres are obtained by reacting melamine with formaldehyde. Wherein, the concentration of formaldehyde solution is 0.0139-0.0278g/ml, such as 0.0139g/ml, 0.0160g/ml, 0.0202g/ml, 0.0253g/ml, 0.0278g/ml, etc. Under the condition of 70-80°C water bath, such as 70°C, 72°C, 75°C, 78°C, 80°C, etc., add melamine to the above formaldehyde solution, and the molar ratio of formaldehyde to melamine in the reaction solution is 4.5-9:1 , such as 4.5:1, 6:1, 7:1, 9:1, etc., to fully react formaldehyde and melamine. After the melamine in the reaction solution is completely dissolved, formic acid is added therein to make the formaldehyde and melamine condense under acidic conditions. For example, dissolve 7.5-15g of formaldehyde solution with a mass concentration of 37% in 200ml of deionized water, add 2.5g of melamine in a water bath at 75°C, and then add 0.15-0.95ml of formic acid to ensure that the formaldehyde and melamine Condensation reactions under acidic conditions. After adding formic acid, continue to stir for 20-50 minutes until the reaction solution is cloudy, such as 20 minutes, 30 minutes, 40 minutes, 50 minutes, etc., and then wash and dry the reaction product to obtain melamine-formaldehyde microsphere powder with a particle size of 50-1950 nm.

In step 102, the melamine-formaldehyde microsphere powder prepared above is used to prepare a melamine-formaldehyde aqueous solution with a mass fraction of 3-5%, and the melamine-formaldehyde microsphere powder is uniformly dispersed in the solution by ultrasonic waves. Then, take 1 volume part of melamine formaldehyde aqueous solution, add 13-18 volume parts of pure water and 45-55 volume parts of isopropanol as a solvent in sequence, and adjust the pH to 7-8 with ammonia water. Then add ethyl orthosilicate (i.e. Tetraethylorthosilicate, TEOS) in reaction solution, stir reaction 4-5h, such as reaction 4h, 4.5h, 5h etc., by the hydrolysis of TEOS and condensation reaction, on the melamine formaldehyde microsphere powder A layer of _SiO2 film is formed, and then the reaction product is filtered and dried to obtain _SiO2 and melamine-formaldehyde composite microspheres.

In step 103, the _SiO2 and melamine-formaldehyde composite microspheres prepared above are put into a muffle furnace for calcination, and the calcination temperature is 500°C-510°C, such as 500°C, 502°C, 505°C, 508°C, 510°C etc., the calcination time is 4-5h, such as 4h, 4.3h, 4.5h, 4.7h, 5h, etc. The melamine-formaldehyde microspheres in the _SiO2 and melamine-formaldehyde composite microspheres are decomposed after being calcined, leaving only the _SiO2 shell, which is the final _SiO2 hollow sphere that needs to be obtained.

In a third aspect, an embodiment of the present invention provides an application of the above-mentioned photoaging-resistant fluororubber composite material in a digital light processing technology laser projection device.

The laser emission ability in laser projection equipment is strong and the energy is highly concentrated. Compared with ordinary light sources, the light energy density of laser light is higher. Long-term irradiation on other components will easily lead to photoaging failure and failure of other components in laser projection equipment. Heat aging fails. Therefore, in order to ensure the reliability of the long-term operation of each component in the laser projection equipment, it is necessary to take certain measures for protection. The anti-aging fluororubber composite material provided by the embodiments of the present invention can be made into various shapes of partitions, gaskets, etc. according to different needs, and placed in laser projection equipment, especially using the principle of DLP (Digital Light Processing, digital light processing) In the laser projection equipment, the laser light source is blocked, thereby reducing the possibility of photoaging failure and thermal aging failure of other components in the laser projection equipment, and prolonging the service life of each component in the laser projection equipment.

There are at least four specific application scenarios for light aging-resistant fluororubber composite materials in digital light processing technology laser projection equipment:

First, as shown in the schematic diagram on the far left of Figure 1, in the DLP laser projection device, the light emitted by the laser light source must pass through the light guide 1, and some light will shine on the outside of the light guide 1. In order to avoid these stray lights The stray light at the light pipe 1 needs to be shielded due to the influence of other components. Therefore, the measure taken in the prior art is to sheath a light pipe metal bracket 2 on the outside of the light pipe 1 , and shield stray light through the light pipe metal bracket 2 . However, the thermal resistance of the metal is small, and the temperature rises after being irradiated by the laser, which causes the temperature of the surrounding components to rise accordingly, thus affecting the reliability of the surrounding components. Therefore, as shown in the schematic diagram in the middle of accompanying drawing 1, adopt the embodiment of the present invention to make the spacer 3 from the light aging fluororubber composite material, as shown in the schematic diagram on the far right side of accompanying drawing 1, put the spacer 3 along the longitudinal direction It is installed on the light pipe 1 and placed in the light pipe metal bracket 2 as a whole to block the stray light in the light pipe 1, thereby protecting other surrounding components and prolonging the service life of each component and laser projection equipment.

Second, as shown in the leftmost schematic diagram of Figure 2, the DLP laser projection device uses DMD (Digital Micromirror Device, digital micromirror chip) as the main key processing element to realize the digital optical processing process, and the DMD 4 plays a sealing role Epoxy resin 5, due to long-term exposure to laser light, is prone to aging, which further leads to the failure of DMD 4. As shown in the schematic diagram in the middle of the accompanying drawing 2, the light-aging fluororubber composite material provided by the embodiment of the present invention is used to make a shielding partition 6 similar in shape to the epoxy resin 5 on the DMD 4, and the epoxy resin 5 and the shielding partition 6 are all rectangular frames, as shown in the schematic diagram on the far right in accompanying drawing 2, covering the epoxy resin 5 on the digital micromirror element with the shielding partition 6 can prevent the laser from directly irradiating the epoxy resin 5 and prevent ring Oxygen 5 aging.

Third, as shown in the leftmost schematic diagram in accompanying drawing 3, the laser vibrating mirror is a device used to control the deflection of the laser beam in the DLP laser projection device. When the laser vibrating mirror receives an off (off) signal, the laser beam (this When the laser beam is in the off state, hereinafter referred to as off light), it will be irradiated on the laser vibrating mirror bracket 7, and the temperature of the laser vibrating mirror bracket 7 will rise after being irradiated by light, and its intensity and other parameters will be affected, resulting in The working reliability of the laser vibrating mirror support 7 becomes worse. The measure taken in the prior art is to shield and absorb the off light with an ink-coated metal sheet, so as to prevent the laser vibrating mirror support 7 from being directly irradiated by the off light. However, due to the small thermal resistance of the metal, the temperature of the laser vibrating mirror bracket 7 also increases due to the large temperature rise after being exposed to light, which is not conducive to maintaining the stability of the laser vibrating mirror bracket 7 . In addition, long-term off-light irradiation will also cause the ink layer on the surface of the metal sheet to volatilize, making the light-shielding and light-absorbing effects of the metal sheet worse. As shown in the middle and rightmost schematic diagram of accompanying drawing 3, the rubber baffle 8 is made of light-resistant aging fluororubber composite material provided by the embodiment of the present invention, and the metal baffle on the laser vibrating mirror bracket 7 is replaced by it, then it can be The heat insulation function of the rubber baffle 8 is used to block and absorb the off light, avoiding the excessive temperature rise of the laser vibrating mirror support 7 and ensuring the long-term use of the laser vibrating mirror support 7 .

Fourth, the off light 9 will also irradiate the housing 10 of the DLP laser projection device, which will cause the housing 10 to age and affect the life of the housing 10 . The measure taken in the prior art is to coat a layer of ink on the surface of the casing 10 , and use the ink layer to absorb off light, so as to avoid premature aging of the casing 10 . However, prolonged exposure to the off light 9 will make the temperature of the housing 10 higher, which will affect the reliability of other surrounding components. In addition, prolonged exposure to the off light 9 will also cause the ink layer to volatilize, changing the ink layer from an absorbing layer to a reflective layer, thereby adversely affecting the use of the housing 10 . As shown in Figure 4-1 and Figure 4-2, the heat-insulating gasket 11 is made of the anti-aging fluororubber composite material provided by the embodiment of the present invention, and the heat-insulating gasket 11 is used to cover the housing 10 with off light 9 to cover the position irradiated by the off light 9 to prevent the off light 9 from directly irradiating the housing 10 , thereby prolonging the aging time of the housing 10 and prolonging the service life of the housing 10 .

Below will be elaborated by specific embodiment:

Example 1

This embodiment provides a light-aging resistant fluororubber composite material, which includes the following components in parts by mass:

100 parts of perfluoroether raw rubber (model: PFR94, provided by Huale Sealing Technology Development Co., Ltd.), 5 parts of SiO ₂ hollow spheres with a particle size of 100nm-2μm, 3 parts of vulcanizing agent (including 2.3 parts of bisphenol AF, benzyl 0.7 part of triphenylphosphorous chloride), 3 parts of paraffin, and 0.4 part of hindered amine light stabilizer (model: 944, produced by BASF AG).

The photoaging-resistant fluororubber composite material is prepared by the following method:

Put 100 parts of perfluoroether raw rubber on an open mill with a roll distance of 0.1mm for 8 minutes, then add 5 parts of _SiO2 hollow spheres, 3 parts of paraffin, and 0.4 parts of hindered amine light stabilizer for 15 minutes of mixing. Then add 3 parts of vulcanizing agent, carry out one-stage vulcanization at 160°C for 15 minutes, and then carry out two-stage vulcanization at 260°C for 30 hours under the protection of nitrogen to obtain a light-resistant aging fluororubber material.

Wherein, SiO Hollow spheres are prepared by the following method _:

Step 1, preparation of melamine formaldehyde microspheres

Dissolve 10g of formaldehyde solution with a mass concentration of 37% in 200ml of deionized water, add 2.5g of melamine in a water bath at 75°C, the molar ratio of formaldehyde to melamine is 6:1, and then add 0.55ml of formic acid to prepare the reaction solution After turbidity, the stirring was continued for 35 minutes, and the reaction product was washed with water and dried to obtain melamine-formaldehyde microspheres.

Step 2, prepare SiO ₂ and melamine formaldehyde composite microsphere

Use the melamine-formaldehyde microsphere powder prepared in step 1 to prepare a melamine-formaldehyde aqueous solution with a mass fraction of 3%. Then, take 1mL of melamine-formaldehyde aqueous solution, add 15mL of pure water and 50mL of isopropanol successively, and adjust the pH with ammonia water To 7.5, after adding TEOS and stirring for 5 hours, the product was suction-filtered and dried to obtain SiO ₂ and melamine-formaldehyde composite microspheres.

Step 3, preparation of SiO ₂ hollow spheres

The SiO ₂ and melamine formaldehyde composite microspheres were calcined in a muffle furnace at 500 °C for 5 h to obtain SiO ₂ hollow spheres.

Example 2

This embodiment provides a light-aging resistant fluororubber composite material, which includes the following components in parts by mass:

100 parts of perfluoroether raw rubber (model: PFR94), 3 parts of SiO ₂ hollow spheres with a particle size of 100nm-2μm, 2.5 parts of vulcanizing agent (including 2 parts of bisphenol AF, 0.5 parts of benzyl triphenyl phosphorus chloride) , 2 parts of paraffin, 0.2 parts of hindered amine light stabilizer (model: 944).

The photoaging-resistant fluororubber composite material is prepared by the following method:

Put 100 parts of perfluoroether raw rubber on an open mill with a roll distance of 0.3mm for 15 minutes, then add 3 parts of _SiO2 hollow spheres, 2 parts of paraffin, and 0.2 parts of hindered amine light stabilizer for 20 minutes of mixing. Then add 2.5 parts of vulcanizing agent, carry out one-stage vulcanization at 155°C for 15 minutes, and then carry out two-stage vulcanization at 290°C for 28 hours under the protection of nitrogen to obtain a light-resistant aging fluororubber material.

Wherein, the preparation method of _SiO2 hollow spheres is the same as that in Example 1.

Example 3

This embodiment provides a light-aging resistant fluororubber composite material, which includes the following components in parts by mass:

100 parts of perfluoroether raw rubber (model: PFR94), 4 parts of _SiO2 hollow spheres with a particle size of 100nm-2μm, 2.7 parts of vulcanizing agent (including 2.1 parts of bisphenol AF, 0.6 parts of benzyl triphenylphosphorous chloride) , 2.7 parts of paraffin, 0.3 parts of hindered amine light stabilizer (model: 944).

The photoaging-resistant fluororubber composite material is prepared by the following method:

Put 100 parts of perfluoroether raw rubber on an open mill with a roll distance of 0.2mm for 12 minutes, then add 4 parts of _SiO2 hollow spheres, 2.7 parts of paraffin wax, and 0.3 parts of hindered amine light stabilizer for 15 minutes of mixing. Then add 2.7 parts of vulcanizing agent, carry out one-stage vulcanization at 165°C for 18 minutes, and then carry out two-stage vulcanization at 230°C for 35 hours under the protection of nitrogen to obtain a light-resistant aging fluororubber material.

Wherein, the preparation method of _SiO2 hollow spheres is the same as that in Example 1.

Application example

Carry out the mensuration of thermal conductivity and light-resistant aging time to the photoaging-resistant fluororubber composite material in embodiment 1-embodiment 3, and take perfluoroether raw rubber as comparative example, compare with the corresponding performance of embodiment 1-embodiment 3 , to test the heat insulation performance and light aging resistance of the light-aging-resistant fluororubber composite material in Example 1-Example 3.

According to the ASTM D5470 standard, the steady-state heat flow meter method is used to apply a certain heat flow and pressure to the test sample, and the thermal conductivity of the sample is obtained by measuring the thickness of the test sample and the temperature difference between the hot plate and the cold plate.

The light aging time is measured by laser. Use a DC power supply (voltage 32V, current 2.5A) to drive the laser to emit blue light, cut the anti-aging fluororubber composite material and perfluoroether raw rubber in Examples 1 to 3 into squares and place them in the same position under the blue light for irradiation , and place a glass slide at the bottom of each test sample. Then, observe whether the test sample is deformed and whether the glass sheet is stained. If the test sample is deformed or the glass sheet is stained, it means that the performance of the test sample has declined and there is aging phenomenon. At this time, the test should be stopped and the time used should be recorded. This time is the light aging time of the test sample.

The test results are shown in Table 1:

Table 1 Test results

Test sample serial number Thermal conductivity (W/MK) Light aging time (h) Example 1 0.1 2200 Example 2 0.15 1200 Example 3 0.12 1800 Comparative example (perfluoroether raw rubber) 0.5 300

As can be seen from Table 1, the thermal conductivity of Examples 1-Example 3 is significantly lower than that of the Comparative Example, indicating that the light-resistant and aging-resistant fluororubber composite material provided by the Example of the present invention has good heat insulation performance, and the insulating material is made of this composite material. Plates, gaskets, etc., can protect the components covered by it and avoid excessive temperature rise of the components. Simultaneously, the light-aging resistance time of embodiment 1-embodiment 3 is also improved significantly compared with comparative example, shows that after above-mentioned improvement, the light-aging resistance fluororubber composite material that the embodiment of the present invention provides can maintain good aging resistance for a long time. In the working state, it provides effective protection for the components covered by it, thereby improving the working stability of the components and prolonging the service life of the components.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in this invention. within the scope of protection of the invention.

Claims (10)

1. A light aging resistant fluororubber composite material, characterized in that, the light aging resistant fluororubber composite material is prepared from the following components by mass: 100 parts of perfluoroether raw rubber, 3-5 parts of SiO ₂ hollow spheres with a particle size of 100nm-2μm, 2.5-3 parts of vulcanizing agent, 2-3 parts of paraffin, and 0.2-0.4 parts of light stabilizer. 2. The anti-aging fluororubber composite material according to claim 1, wherein the vulcanizing agent comprises the following components by mass: Bisphenol AF 2-2.3 parts, benzyl triphenyl phosphorus chloride 0.5-0.7 parts. 3. The photoaging-resistant fluororubber composite material according to claim 1, wherein the light stabilizer is a hindered amine light stabilizer. 4. The preparation method of the light aging resistant fluororubber composite material claimed in claim 1, comprising the following steps: Pour the perfluoroether raw rubber into the open mill, after Botong plasticizing for 8-15min, add _SiO2 hollow balls, paraffin, light stabilizer, knead for 15-20min, then add vulcanizing agent, at 155～165℃ Perform one-stage vulcanization at 230-290° C. for 28-35 hours under the protection of nitrogen or inert gas to obtain the light-resistant aging fluororubber composite material. 5. preparation method according to claim ₄ , is characterized in that, described SiO Hollow sphere is prepared by following method: Step a, prepare melamine formaldehyde microsphere Prepare a formaldehyde solution with a concentration of 0.0139-0.0278g/ml, add melamine in a water bath at 70-80°C, and then add formic acid, continue stirring for 20-50 minutes after the reaction solution is cloudy, wash and dry the reaction product to obtain the Melamine formaldehyde microspheres; Wherein, the mol ratio of described formaldehyde and described melamine is 4.5-9:1; Step b, prepare SiO ₂ and melamine formaldehyde composite microsphere Use the melamine-formaldehyde microspheres to prepare a melamine-formaldehyde aqueous solution with a mass fraction of 3%-5%, then take 1 volume part of the melamine-formaldehyde aqueous solution, add 13-18 volume parts of pure water and 45-55 volume parts isopropanol, adjust the pH to 7-8, add tetraethyl orthosilicate and stir the reaction for 4-5h, and then dry the product by suction filtration to obtain the SiO and melamine _- formaldehyde composite microspheres; Step c, preparing SiO ₂ hollow spheres Calcining the SiO ₂ and melamine formaldehyde composite microspheres at 500-510° C. for 4-5 hours to obtain the SiO ₂ hollow spheres. 6. The application of the photoaging-resistant fluororubber composite material according to claim 1 in digital light processing technology laser projection equipment. 7. The application according to claim 6, characterized in that, the spacer is made of the light aging-resistant fluororubber composite material, and the spacer is sleeved on the light guide along the length direction, and is placed on the metal of the light guide as a whole. Inside the bracket. 8 . The application according to claim 6 , characterized in that, the shielding partition is made of the light aging-resistant fluororubber composite material, and the shielding partition is covered above the epoxy resin on the digital micromirror element. 9. The application according to claim 6, characterized in that the rubber baffle is made of the light-resistant aging fluororubber composite material, which is used to replace the metal baffle on the laser vibrating mirror bracket. 10. The application according to claim 6, characterized in that, the heat-insulating gasket is made of the light-resistant aging fluororubber composite material, and is covered on the housing of the laser projection device irradiated by the light in the off state, Used to block said light.