Preparation method of foam-inhibiting silicon paste and foam-inhibiting silicon paste

Abstract

The invention provides a preparation method of a foam-inhibiting silicon cream and the foam-inhibiting silicon cream, the preparation method of the foam-inhibiting silicon cream comprises the following steps: carrying out a first-step single-double bond addition polymerization reaction on hydrogen-containing silicone oil, a double bond-containing compound and a first catalyst to form a prepolymer, and continuously adding a second catalyst and other raw materials on the basis of the prepolymer to obtain the foam-inhibiting silicon cream. The second catalyst not only can deactivate the first catalyst so as to finish the first-step single-double bond addition reaction, and more importantly, the newly added raw materials can be continuously subjected to secondary polymerization reaction on the basis of the prepolymer so as to form the foam-inhibiting silicon paste with better viscosity, crosslinking degree and performance; by adopting a secondary polymerization method, the cross-linking degree and viscosity of the foam-inhibiting silicon paste are better, the foam-inhibiting performance of the foam-inhibiting silicon paste can still be kept unchanged after strong cutting impact, and the foam-inhibiting performance of the foam-inhibiting silicon paste in the strong impact field of cutting fluid and the like is more than multiple times that of the traditional silicon paste.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial defoaming, and particularly relates to a preparation method of an antifoaming silicone paste and the antifoaming silicone paste. Background Art

[0002] In various cutting processes such as silicon wafer wire cutting and single crystal silicon wafer cutting, although the addition of cutting fluid can timely remove heat, a large amount of foam will be generated due to the addition of substances with different surface tensions such as surfactants in the cutting fluid. If the foam in the synthetic cutting fluid is not eliminated in time, it will overflow the synthetic cutting fluid production and processing system, resulting in waste of cutting fluid raw materials and pollution of the surrounding environment; at the same time, the foam will remain on the surface of the metal processed product, resulting in defects such as water stains and bubble marks on the product surface; the generation of foam will also affect the basic performance and quality of the synthetic cutting fluid, resulting in a decline in the performance of the cutting fluid such as cooling, lubrication, rust prevention, and cleaning. In order to reduce the generation of foam during cutting, an antifoaming agent needs to be added to the cutting fluid to maximize the inhibition of foam generation. Traditional antifoaming agents have limited antifoaming effects during cutting because of their small molecular weight and relatively poor structural stability.

[0003] Therefore, traditional antifoaming agents are difficult to be applied to the cutting field with high shear, and their antifoaming ability is poor. Summary of the Invention

[0004] The present invention provides a preparation method of an antifoaming silicone paste and the antifoaming silicone paste, which are used to solve the problems such as poor antifoaming performance of the existing cutting fluid in the application scenarios of strong impact and high shear.

[0005] In a first aspect, the present invention provides a preparation method of an antifoaming silicone paste, including the following steps:

[0006] (1) Making a first raw material system including hydrogen-containing silicone oil and a double bond-containing compound undergo a single-double bond addition reaction under the catalytic action of a first catalyst to obtain a prepolymer with a viscosity of 5000 - 30000 CS and a two-dimensional structure;

[0007] (2) Making a second raw material system including MQ resin and the prepolymer undergo a secondary polymerization reaction under the catalytic action of a second catalyst to obtain the antifoaming silicone paste with a viscosity of 20000 - 100000 CS and a three-dimensional structure, and adding a terminator to end the secondary polymerization reaction;

[0008] Wherein, the second catalyst is used to deactivate the first catalyst.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: The preparation method of the antifoaming silicone paste provided by the present invention first performs a first step of single-double bond addition polymerization reaction on the hydrogen-containing silicone oil, the double bond-containing compound and the first catalyst to form a prepolymer. On the basis of the prepolymer, a second catalyst and other raw materials are further added. The function of the second catalyst is not only to deactivate the first catalyst, thereby ending the first step of single-double bond addition reaction, but more importantly, it can enable the newly added raw materials to continue to undergo a secondary polymerization reaction on the basis of the prepolymer, forming an antifoaming silicone paste with better viscosity, crosslinking degree and performance; The secondary polymerization method adopted by the present invention makes the crosslinking degree and viscosity of the antifoaming silicone paste better, and it can still maintain its antifoaming performance unchanged after being strongly cut and impacted. Its antifoaming performance in strong impact fields such as cutting fluid is several times that of traditional silicone paste.

[0010] Further, the first raw material system includes, by mass: 60-100 parts of hydrogen-containing silicone oil, 50-80 parts of vinyl silicone oil, 60-100 parts of methyl silicone oil, 5-10 parts of silica, and 3-15 parts of hexamethyldisiloxane.

[0011] Further, the second raw material system includes, by mass: 10-30 parts of MQ resin and 10-40 parts of prepolymer.

[0012] Further, the first catalyst includes at least one of a platinum-based catalyst or a rhodium-based catalyst; and / or, the second catalyst includes at least one of KOH alkali glue and tetramethylammonium hydroxide alkali glue; and / or, the terminator includes at least one of phosphoric acid and carbon dioxide.

[0013] Further, the addition amount of the first catalyst accounts for 0.5%-2% of the mass of the first raw material system; and / or, the addition amount of the second catalyst in terms of molar number is 1.5-3.0 times that of the first catalyst; and / or, the addition amount of the terminator in terms of molar number is 0.5 times that of the second catalyst.

[0014] Further, in step (2), the second catalyst is first added to the prepolymer for stirring treatment.

[0015] Further, the stirring treatment time is 5-30 min, the temperature is 10-30 °C, and the stirring speed is 100-1000 rpm.

[0016] Further, the hydrogen content of the hydrogen-containing silicone oil is 0.08-1.4%.

[0017] Further, the reaction temperature of the single-double bond addition reaction is 10-30 °C, and the reaction time is 30-90 min; and / or, the reaction temperature of the secondary polymerization reaction is 120-150 °C, and the reaction time is 2-4 h.

[0018] In a second aspect, the present invention provides an anti-foaming silicone paste, which is prepared by using the preparation method of the anti-foaming silicone paste described in the first aspect. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] In a first aspect, the present invention provides a preparation method of an anti-foaming silicone paste, including the following steps:

[0021] (1) A first raw material system including a hydrogen-containing silicone oil and a double-bond-containing compound is subjected to a single-double bond addition reaction under the catalysis of a first catalyst to obtain a prepolymer having a two-dimensional structure with a viscosity of 5000 to 30000 CS;

[0022] (2) A second raw material system including an MQ resin and the prepolymer is subjected to a secondary polymerization reaction under the catalysis of a second catalyst to obtain the anti-foaming silicone paste having a three-dimensional structure with a viscosity of 20000 to 100000 CS, and a terminator is added to end the secondary polymerization reaction;

[0023] Wherein, the second catalyst is used to deactivate the first catalyst.

[0024] Wherein, a first step of polymerization is completed by using a hydrogen-containing silicone oil and a double-bond-containing compound under the action of a first catalyst to obtain a prepolymer, and a second step of polymerization is carried out by using the prepolymer and an MQ resin as raw materials under the action of a second catalyst to obtain the anti-foaming silicone paste.

[0025] The preparation method of the anti-foaming silicone paste provided by the present invention forms a prepolymer through a first-step single-double bond addition polymerization reaction of a hydrogen-containing silicone oil, a double-bond-containing compound and a first catalyst. On the basis of the prepolymer, a second catalyst and other raw materials are continuously added. The function of the second catalyst is not only to deactivate the first catalyst, thereby ending the first-step single-double bond addition reaction, but more importantly, it can cause the newly added raw materials to continue to undergo a secondary polymerization reaction on the basis of the prepolymer, forming an anti-foaming silicone paste with better viscosity, crosslinking degree and performance; the secondary polymerization method adopted by the present invention makes the crosslinking degree and viscosity of the anti-foaming silicone paste better, and it can still maintain its anti-foaming performance unchanged after strong cutting and impact. Its anti-foaming performance in strong impact fields such as cutting fluids is several times that of traditional silicone pastes.

[0026] In a specific embodiment, the first raw material system comprises, by mass parts: 60 - 100 parts of hydrogen-containing silicone oil, 50 - 80 parts of vinyl silicone oil, 60 - 100 parts of methyl silicone oil, 5 - 10 parts of silica, and 3 - 15 parts of hexamethyldisiloxane.

[0027] By defining the mass part ranges of the components in the first raw material system, the present invention further optimizes the raw material ratio of the single-double bond addition reaction, making the viscosity, molecular weight, and structure of the prepolymer more uniform, thereby providing a more stable basis for the subsequent secondary polymerization reaction and further improving the foam suppression performance and mechanical stability of the foam suppression silicone paste.

[0028] In a specific embodiment, the second raw material system comprises, by mass parts: 10 - 30 parts of MQ resin and 10 - 40 parts of prepolymer.

[0029] By defining the mass part ranges of MQ resin and prepolymer in the second raw material system, the present invention further ensures the sufficiency and controllability of the secondary polymerization reaction. The addition of MQ resin significantly improves the crosslinking degree and heat resistance of the foam suppression silicone paste; further, raw materials such as methyl silicone oil can be added to further improve its fluidity and dispersibility, enabling the final product to still maintain excellent foam suppression performance under strong impact conditions.

[0030] Further, the first catalyst includes a platinum-based catalyst or a rhodium-based catalyst, the second catalyst includes at least one of KOH alkali gel and tetramethylammonium hydroxide alkali gel, and the terminator includes at least one of phosphoric acid and carbon dioxide.

[0031] By defining the types of the first catalyst and the second catalyst and reasonably selecting the terminator, the present invention further ensures the efficient progress of the single-double bond addition reaction and the secondary polymerization reaction, and also avoids the occurrence of over-reaction or side reactions, thereby improving the purity and performance stability of the product.

[0032] Specifically, the addition amount of the first catalyst accounts for 0.5% - 2% of the mass of the first raw material system, the addition amount of the second catalyst in terms of moles is 1.5 - 3.0 times that of the first catalyst, and the addition amount of the terminator in terms of moles is 0.5 times that of the second catalyst.

[0033] By specifically defining the addition amounts of the first catalyst, the second catalyst, and the terminator, the present invention further precisely controls the reaction process and termination timing, avoids problems such as incomplete reaction or product performance degradation caused by excessive or insufficient catalyst, and further optimizes the viscosity, crosslinking degree, and foam suppression performance of the foam suppression silicone paste.

[0034] Optionally, in step (2), the second catalyst is first added to the prepolymer for stirring treatment.

[0035] By adding a second catalyst to the prepolymer and performing a stirring treatment before the secondary polymerization reaction, the present invention ensures the uniform dispersion of the catalyst and the homogeneity of the reaction system, further improving the efficiency of the secondary polymerization reaction and the performance consistency of the product.

[0036] Optionally, the time of the stirring treatment is 5 - 30 min, the temperature is 10 - 30 °C, and the stirring speed is 100 - 1000 rpm.

[0037] By defining the time, temperature, and stirring speed of the stirring treatment, the process conditions of the secondary polymerization reaction are further optimized, ensuring the uniformity of the reaction system and the reaction efficiency, thereby improving the mechanical stability and foam suppression performance of the foam suppression silicone paste.

[0038] In a specific embodiment, the hydrogen content of the hydrogen-containing silicone oil is 0.08 - 1.4%.

[0039] By specifically defining the hydrogen content of the hydrogen-containing silicone oil, the sufficiency and controllability of the single-double bond addition reaction and the secondary polymerization reaction are further improved, thereby improving the crosslinking degree, viscosity, and mechanical properties of the foam suppression silicone paste, enabling it to maintain excellent foam suppression performance under strong impact conditions.

[0040] Specifically, the reaction temperature of the single-double bond addition reaction is 10 - 30 °C, the reaction time is 30 - 90 min, the reaction temperature of the secondary polymerization reaction is 120 - 150 °C, and the reaction time is 2 - 4 h.

[0041] By further defining the reaction temperature and time of the single-double bond addition reaction and the secondary polymerization reaction, the reaction conditions are optimized, further improving the efficiency of the reaction and the performance stability of the product, thereby improving the foam suppression performance and durability of the foam suppression silicone paste.

[0042] In a second aspect, the present invention provides a foam suppression silicone paste prepared by using the preparation method of the foam suppression silicone paste described in the first aspect.

[0043] The foam suppression silicone paste provided by the present invention, by adopting the above preparation method, has excellent viscosity, crosslinking degree, and mechanical stability, and can still maintain its foam suppression performance unchanged under strong impact conditions. It is particularly suitable for strong impact fields such as cutting fluid, and its foam suppression performance is several times that of traditional silicone paste.

[0044] Hereinafter, the preparation method of the foam suppression silicone paste provided by the present invention will be introduced in detail through specific examples.

[0045] Example 1

[0046] (1) Preparation of prepolymer: 60 parts of hydrogen-containing silicone oil with a hydrogen content of 0.18%, 100 parts of vinyl silicone oil, 80 parts of methyl silicone oil, 10 parts of fumed silica, and 2 parts of hexamethyldisiloxane were added to a reactor, stirred at room temperature until evenly mixed, and a complex catalyst (chloroplatinic acid) with a mass of 1‰ - 1% of the total mass was added to the reactor. A single-double bond addition reaction was carried out at 25°C for 30 minutes to obtain a prepolymer with a viscosity of 40000 CS and a two-dimensional structure;

[0047] (2) 1% - 5% of KOH alkali gel catalyst based on the total mass was added to the reactor. After stirring for 5 minutes, 20 parts of MQ103 resin were added, and the temperature was raised to 120°C for a second polymerization reaction for 2 hours to obtain the antifoaming silicone paste with a three-dimensional structure and a viscosity of 80000 CS. A phosphoric acid solution with a mass of 1% - 3% of the total mass was added to end the second polymerization reaction.

[0048] Example 2

[0049] The difference between this example and Example 1 is that in step (1), 60 parts of hydrogen-containing silicone oil with a hydrogen content of 0.08%, 50 parts of vinyl silicone oil, 60 parts of methyl silicone oil, 5 parts of fumed silica, and 3 parts of hexamethyldisiloxane were added to the reactor; and the viscosity of the prepolymer was 20000 CS, and the viscosity of the antifoaming silicone paste was 40000 CS.

[0050] Example 3

[0051] The difference between this example and Example 1 is that in step (1), 60 parts of hydrogen-containing silicone oil with a hydrogen content of 0.08%, 100 parts of vinyl silicone oil, 60 parts of methyl silicone oil, 5 parts of fumed silica, and 3 parts of hexamethyldisiloxane were added to the reactor; and the viscosity of the prepolymer was 25000 CS, and the viscosity of the antifoaming silicone paste was 50000 CS.

[0052] Comparative Example 1

[0053] Commercially available silicone paste was selected.

[0054] Test Example 1

[0055] The silicone paste of each of the above examples and comparative examples was mixed with formaldehyde at a mass ratio of 1:1. Another prepared bubble liquid was placed in a detection device. After strong mechanical vibration, 1 ml of the dissolved silicone paste was added, and then mechanical oscillation detection was repeated. The test temperature was 25°C. The specific test results are shown in Table 1.

[0056] Table 1

[0057] Group Defoaming time First foam suppression Foam suppression time (10 times) Example 1 10s 5s 5s Example 2 15s 7.5s 8s Example 3 14s 7.4s 7s Comparative example 1 30s 10s 58s

[0058] The defoaming silicone paste provided by the present invention has no obvious performance decline after dozens of detections, and the silicone paste still has good defoaming ability. In the comparative example, the defoaming ability of the ordinary silicone paste significantly declines after 10 times. It can be seen that the silicone paste formed by two-step polymerization can be used in the fields of strong shearing and violent mechanical vibration.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; if these modifications and variations fall within the scope of the claims of the present invention and its equivalent technologies, they should all be considered as the protection scope of the present invention.

Claims

1. A preparation method of an antifoaming silicone paste, characterized in that, It includes the following steps: (1) Making a first raw material system including hydrogen-containing silicone oil and double bond-containing compound undergo a single-double bond addition reaction under the catalysis of a first catalyst to obtain a prepolymer with a viscosity of 5000 - 30000 CS and a two-dimensional structure; (2) Making a second raw material system including MQ resin and the prepolymer undergo a secondary polymerization reaction under the catalysis of a second catalyst to obtain the anti-foaming silicone paste with a viscosity of 20000 - 100000 CS and a three-dimensional structure, and adding a terminator to end the secondary polymerization reaction; Wherein, the second catalyst is used to deactivate the first catalyst.

2. The preparation method of the antifoaming silicone paste according to claim 1, characterized in that, The first raw material system includes, by mass parts: 60 - 100 parts of hydrogen-containing silicone oil, 50 - 80 parts of vinyl silicone oil, 60 - 100 parts of methyl silicone oil, 5 - 10 parts of fumed silica, 3 - 15 parts of hexamethyldisiloxane.

3. The preparation method of the anti-foaming silicone paste according to claim 1, characterized in that, The second raw material system includes, by mass parts: 10 - 30 parts of MQ resin, 10 - 40 parts of prepolymer.

4. The preparation method of the antifoaming silicone paste according to claim 1, characterized in that, The first catalyst includes at least one of platinum-based catalysts or rhodium-based catalysts; and / or, The second catalyst includes at least one of KOH alkali glue and tetramethylammonium hydroxide alkali glue; and / or, The terminator includes at least one of phosphoric acid and carbon dioxide.

5. The preparation method of the anti-foaming silicone paste according to claim 4, characterized in that, The addition amount of the first catalyst accounts for 0.5% - 2% of the mass of the first raw material system; and / or, The addition amount of the second catalyst in terms of molar number is 1.5 - 3.0 times that of the first catalyst; and / or, The addition amount of the terminator in terms of molar number is 0.5 times that of the second catalyst.

6. The preparation method of the antifoaming silicone paste according to claim 1, characterized in that, In step (2), first add the second catalyst to the prepolymer and carry out stirring treatment.

7. The preparation method of the anti-foaming silicone paste according to claim 6, characterized in that, The time of the stirring treatment is 5 - 30 min, the temperature is 10 - 30 °C, and the stirring speed is 100 - 1000 rpm.

8. The preparation method of the defoaming silicone paste according to any one of claims 1 to 7, characterized in that, The hydrogen content of the hydrogen-containing silicone oil is 0.08% - 1.4%.

9. The preparation method of the anti-foaming silicone paste according to any one of claims 1 to 7, characterized in that, The reaction temperature of the single-double bond addition reaction is 10 - 30 °C, and the reaction time is 30 - 90 min; and / or, The reaction temperature of the secondary polymerization reaction is 120 - 150 °C, and the reaction time is 2 - 4 h.

10. An anti-foaming silicone paste, characterized in that, It is prepared by using the preparation method of the anti-foaming silicone paste according to any one of claims 1 - 9.