阅读说明：本技术 一种硅橡胶海绵及其制备方法 (Silicone rubber sponge and preparation method thereof ) 是由 吴忧 董海亚 马静 胡学军 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种硅橡胶海绵及其制备方法,硅橡胶海绵其原料包括以下质量份的各组分：硅橡胶100份；白炭黑10-50份；结构控制剂0.5-10份；甲基硅油0-100份；发泡剂3-12份；还原铁粉5-10份；铝粉0.5-3份；黄原胶2-5份；氯化钠1-5份；蛭石3-15份；活性炭3-15份；硫化剂1-4份。硅橡胶海绵的制备方法包括以下步骤：(1)称取原料；(2)混炼：采用多段混炼方法进行混炼,每一段混炼完后进行停放；(3)硫化发泡。本发明中,还原铁粉、铝粉、黄原胶、氯化钠、蛭石、活性炭搭配合理,组合在一起后,可以吸收空气中的水分进行放热,可以使得海绵中间具有一定的温度,促进海绵的均匀发泡,可以明显的降低海绵的表观密度,海绵整体孔隙均匀度更好。(The invention discloses a silicone rubber sponge and a preparation method thereof, wherein the silicone rubber sponge comprises the following components in parts by mass: 100 parts of silicon rubber; 10-50 parts of white carbon black; 0.5-10 parts of a structure control agent; 0-100 parts of methyl silicone oil; 3-12 parts of a foaming agent; 5-10 parts of reduced iron powder; 0.5-3 parts of aluminum powder; 2-5 parts of xanthan gum; 1-5 parts of sodium chloride; 3-15 parts of vermiculite; 3-15 parts of activated carbon; 1-4 parts of a vulcanizing agent. The preparation method of the silicone rubber sponge comprises the following steps: (1) weighing raw materials; (2) mixing: mixing by adopting a multi-section mixing method, and standing after each section is mixed; (3) and (4) vulcanizing and foaming. According to the sponge, the reduced iron powder, the aluminum powder, the xanthan gum, the sodium chloride, the vermiculite and the activated carbon are reasonably matched, and after the reduced iron powder, the aluminum powder, the xanthan gum, the sodium chloride, the vermiculite and the activated carbon are combined together, moisture in air can be absorbed for heat release, a certain temperature can be kept in the middle of the sponge, the sponge is promoted to be uniformly foamed, the apparent density of the sponge can be obviously reduced, and the uniformity of the whole pores of the sponge is better.)

1. The silicone rubber sponge is characterized by comprising the following raw materials in parts by mass:

2. the silicone rubber sponge according to claim 1, wherein the silicone rubber is one or more of methyl vinyl silicone rubber and phenyl silicone rubber.

3. The silicone rubber sponge according to claim 1, wherein the white carbon black is one or a combination of precipitated white carbon black and fumed white carbon black.

4. The silicone rubber sponge according to claim 1, wherein the structure-controlling agent is a hydroxy silicone oil or a phenyl silicone glycol.

5. The silicone rubber sponge according to any one of claims 1 to 4, wherein the blowing agent is one or more of azo blowing agents, benzenesulfonyl hydrazide blowing agents and urea blowing agents; the vulcanizing agent is one or more of a bis-penta vulcanizing agent and a bis-tetratetra vulcanizing agent.

6. The silicone rubber sponge according to any one of claims 1 to 4, wherein the reduced iron powder has a particle size of less than 320 mesh; the particle size of the aluminum powder is less than 100 meshes; the particle size of the vermiculite is less than 50 meshes; the particle size of the activated carbon is less than 320 meshes.

7. The silicone rubber sponge according to any one of claims 1 to 4, wherein the raw material of the silicone rubber sponge further comprises: 0-100 parts of methyl silicone oil.

8. A method of preparing a silicone rubber sponge according to any of claims 1 to 7, comprising the steps of:

(1) weighing raw materials;

(2) mixing: mixing by adopting a multi-section mixing method, and standing after each section is mixed;

(3) and (4) vulcanizing and foaming.

9. The method for preparing the silicone rubber sponge according to claim 8, wherein the step (2) specifically comprises the steps of:

firstly, mixing: mixing the first-stage mixing by adopting an open mill or mixing the first-stage mixing by adopting the open mill and a vacuum internal mixer in a matching way;

when the open mill is adopted for mixing in the first-stage mixing, the feeding sequence is as follows: silicone rubber → white carbon black accounting for 30-70% of the total mass of the white carbon black → structural control agent → the rest white carbon black → methyl silicone oil → reduced iron powder, aluminum powder, sodium chloride, vermiculite, activated carbon, xanthan gum → foaming agent and vulcanizing agent, mixing, and sealing and parking for 1-7 days after the obtained rubber material is thinly passed through the lower sheet, wherein the parking environment temperature is lower than 37 ℃;

when an open mill and a vacuum internal mixer are matched for mixing in one section of mixing, firstly, the vacuum internal mixer is used for mixing, and the feeding sequence is as follows: silicone rubber → white carbon black accounting for 30-70% of the total mass of the white carbon black → structural control agent → the rest white carbon black → methyl silicone oil → sodium chloride, vermiculite, activated carbon and xanthan gum, then mixing by adopting an open mill, and adding foaming agent, reduced iron powder, aluminum powder and vulcanizing agent into the open mill, wherein the roll temperature is less than 60 ℃;

② two-stage mixing: and (3) thinly passing the sizing material obtained after the treatment in the step (i), packaging in a triangular mode, discharging, and hermetically standing for 1-7 days at the temperature of the standing environment being less than 37 ℃.

10. The method for preparing a silicone rubber sponge according to claim 8 or 9, wherein in step (3), a compression-molded vulcanization foam or a non-compression-molded vulcanization foam is used.

Technical Field

The invention belongs to the technical field of rubber sponge materials, and particularly relates to a silicone rubber sponge and a preparation method thereof.

Background

The sponge is a widely used porous low-density material, has the characteristics of heat preservation, heat insulation, sound absorption, shock absorption, flame retardance, static prevention, good air permeability and the like, and is widely used in various industries.

The silicone rubber sponge integrates the performance of the silicone elastomer and the performance of the porous material, not only has the characteristics of excellent high and low temperature resistance, aging resistance, good insulating property, physiological inertia, chemical stability and the like of the silicone rubber, but also has the performances of sound insulation, heat insulation, light weight, impact load absorption, sealing and the like of the porous material. Because of the excellent comprehensive performance and the performance that other elastomers can not replace, the elastomer has better application prospect in the fields of new energy, electronics, orbits, and particularly national defense. Silicon rubber is generally used as a reinforcing agent by adding white carbon black, and the density is reduced after foaming, so that the heat conducting property of the silicon rubber is reduced, in the foaming process, heat on two sides of equipment or a mould can not be completely transmitted to the middle of the sponge, the interior of the sponge is heated and is inconsistent with two sides of the sponge, the density uniformity of the sponge is further influenced, and meanwhile, the foaming thickness of the sponge is limited because the heat can not reach the middle.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects and shortcomings in the background art and provide a silicone rubber sponge and a preparation method thereof.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the silicone rubber sponge comprises the following raw materials in parts by mass:

the reduced iron powder, the aluminum powder, the xanthan gum, the sodium chloride, the vermiculite and the activated carbon are reasonably matched, and after the reduced iron powder, the aluminum powder, the xanthan gum, the sodium chloride, the vermiculite and the activated carbon are combined together, moisture in air can be absorbed for heat release, so that a certain temperature is kept in the middle of the sponge, and the uniform foaming of the sponge is promoted. Furthermore, the reduced iron powder and the aluminum powder also have good heat conduction effect, and can better conduct heat on equipment or a die to the middle part of the sponge; the vermiculite can absorb moisture in the reaction process, promote the reaction with the reduced iron powder and the aluminum powder, simultaneously has better heat preservation effect, and can keep heat in the middle of the sponge; the xanthan gum can effectively absorb moisture in the air, and further promote the reaction of each material and the moisture to generate heat.

Preferably, the silicone rubber is one or more of methyl vinyl silicone rubber and phenyl silicone rubber.

Preferably, the white carbon black is one or a combination of two of precipitated white carbon black and gas-phase white carbon black.

Preferably, the structure control agent is hydroxy silicone oil or phenyl silicone glycol.

Preferably, the foaming agent is one or more of azo foaming agents, benzenesulfonyl hydrazide foaming agents and ureido foaming agents; the vulcanizing agent is one or more of a bis-penta vulcanizing agent and a bis-tetratetra vulcanizing agent.

Preferably, the particle size of the reduced iron powder is less than 320 meshes; the particle size of the aluminum powder is less than 100 meshes; the particle size of the vermiculite is less than 50 meshes; the particle size of the activated carbon is less than 320 meshes.

Preferably, the raw materials of the silicone rubber sponge further comprise: 0-100 parts of methyl silicone oil.

As a general inventive concept, the present invention also provides a method for preparing a silicone rubber sponge, comprising the steps of:

(1) weighing raw materials;

(2) mixing: mixing by adopting a multi-section mixing method, and standing after each section is mixed;

(3) and (4) vulcanizing and foaming.

In the above preparation method, preferably, the step (2) specifically includes the steps of:

firstly, mixing: mixing the first-stage mixing by adopting an open mill or mixing the first-stage mixing by adopting the open mill and a vacuum internal mixer in a matching way;

when the open mill is adopted for mixing in the first-stage mixing, the feeding sequence is as follows: silicone rubber → white carbon black accounting for 30-70% of the total mass of the white carbon black → structural control agent → the rest white carbon black → methyl silicone oil → reduced iron powder, aluminum powder, sodium chloride, vermiculite, activated carbon, xanthan gum → foaming agent and vulcanizing agent, mixing, and sealing and parking for 1-7 days after the obtained rubber material is thinly passed through the lower sheet, wherein the parking environment temperature is lower than 37 ℃;

when an open mill and a vacuum internal mixer are matched for mixing in one section of mixing, firstly, the vacuum internal mixer is used for mixing, and the feeding sequence is as follows: silicone rubber → white carbon black accounting for 30-70% of the total mass of the white carbon black → structural control agent → the rest white carbon black → methyl silicone oil → sodium chloride, vermiculite, activated carbon and xanthan gum, then mixing by adopting an open mill, and adding foaming agent, reduced iron powder, aluminum powder and vulcanizing agent into the open mill, wherein the roll temperature is less than 60 ℃;

② two-stage mixing: and (3) thinly passing the sizing material obtained after the treatment in the step (i), packaging in a triangular mode, discharging, and hermetically standing for 1-7 days at the temperature of the standing environment being less than 37 ℃.

If necessary, three-stage kneading may be carried out.

Preferably, in the step (3), the foam is vulcanized and foamed by a molding method or is not foamed by molding and vulcanization.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, by adding the reduced iron powder, the sodium chloride, the vermiculite, the activated carbon, the xanthan gum and the aluminum powder, the apparent density of the sponge can be obviously reduced, and the overall pore uniformity of the sponge is better.

2. The silicone rubber sponge prepared by the invention has more uniform density and slightly increased thickness compared with the traditional formula.

Detailed Description

In order to facilitate an understanding of the present invention, the present invention will be described more fully and in detail with reference to the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

Comparative examples 1-2 and examples 1-4:

the proportions of the silicone rubber sponge raw materials in comparative examples 1-2 and examples 1-4 are shown in Table 1:

TABLE 1 proportioning table of silicon rubber sponge raw materials (by mass)

Name of Material	Comparative example 1	Comparative example 2	Example 1	Example 2	Example 3	Example 4
							Silicone rubber 110-2	100	100	100	100	100	100
White carbon black ZQ356	20	20	20	20	20	20
							Hydroxy silicone oil 209	3	3	3	3	3	3
201 methyl silicone oil	15	15	15	15	15	15
							Foaming agent AC	2	2	1	3	3	2
Foaming agent OBSH	4	4	2	6	6	4
							Reduced iron powder	0	9	9	9	9	4.5
Sodium chloride	0	4	4	4	4	2
							Vermiculite	0	6	6	6	6	3
Xanthan gum	5	0	5	5	5	2.5
							Aluminum powder	3	0	3	3	3	1.5
Activated carbon	0	3	3	3	3	1.5
							Bierwu vulcanizing agent	0.5	0.5	0.5	0.5	1	0.5

The particle size of the reduced iron powder in the proportioning table is below 400 meshes; the particle size of the vermiculite is below 60 meshes; the particle size of the aluminum powder is less than 320 meshes; the particle size of the activated carbon is 400 meshes or less.

The preparation method of the silicone rubber sponge comprises the following steps:

(1) weighing the following raw materials: accurately weighing the raw materials according to the mixture ratio in the table 1;

(2) mixing:

firstly, mixing: mixing the first-stage mixture by using an open mill, wherein the feeding sequence is as follows: silicone rubber → white carbon black accounting for 40% of the total mass of the white carbon black → hydroxy silicone oil → the rest white carbon black → methyl silicone oil → reduced iron powder, aluminum powder, sodium chloride, vermiculite, activated carbon, xanthan gum → foaming agent and vulcanizing agent, mixing, and sealing and parking for 2 days after the obtained rubber material is thinly put into a lower sheet, wherein the parking environment temperature is lower than 37 ℃;

② two-stage mixing: and (3) thinly passing the sizing material obtained after the treatment in the step (I), packaging in a triangular mode, discharging, and sealing and standing for 2 days, wherein the standing ambient temperature is lower than 37 ℃.

(3) And (3) vulcanization foaming: and vulcanizing and foaming by adopting a mould pressing method, accurately weighing the rubber material after preparing the rubber material into a required sheet, and vulcanizing and foaming for 20 minutes in a flat plate at 160 ℃.

The data of the performance tests of the compounds and silicone sponges prepared from the raw materials of comparative examples 1-2 and examples 1-4 by the above-described method are shown in table 2:

TABLE 2 Performance test data for rubber compounds and silicone rubber sponges

As can be seen from Table 2, it can be seen from comparative examples 1-2 and examples 1-4 that the addition of reduced iron powder, sodium chloride, vermiculite, activated carbon, xanthan gum and aluminum powder can significantly reduce the apparent density of the sponge, and the uniformity of the overall pores of the sponge is better. When the amount of the combination is reduced, the apparent density of the sponge increases, and the uniformity of the pores of the sponge becomes poor. In addition, the apparent density of the sponge can be effectively adjusted by adjusting the amounts of the foaming agent and the vulcanizing agent, but the effect on the overall compactness and uniformity of the sponge is not achieved.