An acrylate-modified silicone oil, a preparation method thereof, and application thereof in preparing a photocuring release agent

Abstract

An acrylate-modified silicone oil, its preparation method, and its application in the preparation of photocurable release agents are disclosed. This invention belongs to the field of organosilicon technology. The acrylate-modified silicone oil of this invention comprises the following raw materials in parts by weight: 5-15 parts of 3-(diethoxymethylsilyl)propyl 2-acrylate, 80-100 parts of a mixture of dimethylcyclosiloxanes, 0.06-1 part of hexamethyldisiloxane, 0.03-1 part of an acid solution, and 10-30 parts of a dehydrating agent. This invention uses fewer types of raw materials, and the synthesized acrylate-modified silicone oil has a simple molecular structure and does not contain functional groups with special structures. This invention can synthesize a high-viscosity silicone oil with a high acrylate content by using dehydrating agents such as 4A molecular sieves in the raw materials.

Description

Technical Field

[0001] This application belongs to the field of organosilicon technology, and specifically relates to an acrylate-modified silicone oil, its preparation method, and its application in the preparation of photocurable release agents. Background Technology

[0002] Release agents, also known as release agents, are low surface energy polymers coated on the surface of release films. Classified by chemical composition, release agents are mainly divided into non-silicone release agents, silicone release agents, and fluorosilicone release agents. Among them, silicone release agents are the most commonly used. Based on different reaction mechanisms, silicone release agents are mainly divided into three categories: addition-type, condensation-type, and radiation-cured types. Radiation-cured types include UV curing and electron beam irradiation curing.

[0003] Addition-cure silicone release agents are stable, do not release small molecules during the reaction process, have a fast reaction rate, and high production efficiency. In addition to solvent-based release agents, solvent-free and emulsion-type release agents have also been developed, reducing environmental pollution and the occurrence of hazardous situations. Therefore, addition-cure silicone release agents are currently the most widely used type of release agent. However, addition-cure silicone release agents require relatively high temperatures for coating, making them unsuitable for some substrates with poor temperature resistance, thus limiting their application.

[0004] UV-curable release agents appeared relatively late. They do not use heating to cure the film, but require UV light irradiation of a certain wavelength to crosslink and cure. Compared with addition-type silicone release agents, UV-curable silicone release agents have the following advantages: (1) The reaction process does not require heating, making them suitable for substrates with poor heat resistance such as PP and PE; (2) They do not contain organic solvents, are environmentally friendly, and pose no safety hazards such as fire or explosion during storage, transportation, and production; (3) The reaction speed is fast, and it can be completed within a few seconds, greatly improving production efficiency; (4) UV-curable coating equipment does not require a long heating oven, so it occupies a small area and saves production space; (5) The release agent does not require heating during the coating process, only UV light irradiation, so energy consumption is low. Although UV-curable silicone release agents have many performance advantages and can basically replace traditional condensation and addition-type silicone release agents, they have not yet been fully accepted by users and have not been widely adopted in the market, mainly due to their high price and complex molecular structure.

[0005] The main components of UV-curable silicone release agents are polysiloxanes modified with special functional groups and photoinitiators with special structures. These products have high technical content and complex production processes. For example, patent CN110183664B discloses a method for preparing and applying a UV-curable silicone oil containing methacrylate. This patent first synthesizes an organic compound with a methacrylate structure containing a mercapto group. Secondly, it reacts with an epoxy-terminated polymethylsiloxane. Under the catalysis of an organic base, the mercapto group efficiently and rapidly performs a ring-opening click chemical reaction on propylene oxide to prepare polymethylsiloxane (PSi-MMA) with an epoxy-terminated structure. The entire reaction is carried out in two steps and uses a variety of raw materials.

[0006] Currently, most commercially available photocurable release agents utilize a free radical curing mode, relying on acrylate functional groups to promote curing under photoinitiator conditions. The presence of these acrylate functional groups prevents the release agent from being heated, increasing the difficulty of the purification process during production. Although patents report methods to purify silicone oil by heating it to 140 degrees Celsius using vacuum distillation, practical experience has shown that at this temperature, excessively high acrylate content greatly increases the likelihood of acrylate self-polymerization, leading to gelation.

[0007] Based on the above analysis, it is very important to provide an acrylate-modified silicone oil that is a light-curing release agent with simple raw materials, a simple preparation process, and a low purification temperature. Summary of the Invention

[0008] To address the shortcomings of existing technologies and to solve the problems of complex molecular structures and cumbersome preparation processes in photocurable release agents, this invention aims to provide an acrylate-modified silicone oil, its preparation method, and its application in the preparation of photocurable release agents. This invention uses fewer types of raw materials, and the synthesized acrylate-modified silicone oil has a simple molecular structure, free of functional groups with special structures. Furthermore, this invention can synthesize a high-viscosity silicone oil with a high acrylate content by using dehydrating agents such as 4A molecular sieves in the raw materials.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] On one hand, the present invention provides an acrylate-modified silicone oil comprising the following raw materials in parts by weight: 5-15 parts of 3-(diethoxymethylsilyl)propyl 2-acrylate, 80-100 parts of a mixture of dimethylcyclosiloxanes, 0.06-1 part of hexamethyldisiloxane, 0.03-1 part of an acid solution, and 10-30 parts of a dehydrating agent;

[0011] Preferably, the acid solution is trifluoromethanesulfonic acid or sulfuric acid;

[0012] Preferably, the dehydrating agent is 4A molecular sieve, anhydrous magnesium sulfate, anhydrous calcium chloride, or anhydrous sodium sulfate. This invention, by adding 4A molecular sieve to the raw materials, can synthesize high-viscosity silicone oil with a high acrylate content. If the molecular sieve is not added, the viscosity of the silicone oil will decrease with increasing acrylate content.

[0013] The acrylate-modified silicone oil has the following structural formula (Formula I):

[0014]

[0015] Where n is an integer between 100 and 250; o is an integer between 5 and 15.

[0016] Secondly, the present invention provides a method for preparing an acrylate-modified silicone oil, comprising the following steps:

[0017] Weigh out a mixture of dimethylcyclosiloxane and hexamethyldisiloxane, heat it, and after the temperature stabilizes, add an acid solution, stir evenly, add a dehydrating agent, add dropwise 3-(diethoxymethylsilyl)propyl 2-acrylate, stir, adjust the pH value to neutral (preferably, by adding anhydrous sodium carbonate for neutralization), filter, and distill at low temperature to obtain acrylate-modified silicone oil.

[0018] Preferably, the heating is carried out at 30–60°C;

[0019] Preferably, the conditions for the low-temperature distillation are: vacuum degree 5-12 Pa and temperature 85-90°C. This invention reduces the temperature required for purification, thereby reducing the risk of silicone oil self-polymerization during the purification process.

[0020] Thirdly, the present invention provides the application of the acrylate-modified silicone oil, or the acrylate-modified silicone oil obtained by the preparation method, in the preparation of photocurable release agents.

[0021] Fourthly, the present invention provides a photocurable release agent comprising the following parts by weight of raw materials: 100 parts of the acrylate-modified silicone oil and 1-2 parts of photoinitiator;

[0022] Preferably, the photoinitiator is photoinitiator 1173 and / or photoinitiator 184.

[0023] Fifthly, the present invention provides a method for preparing a photocurable release agent, wherein acrylate-modified silicone oil is mixed with a photoinitiator to obtain a photocurable release agent.

[0024] Sixthly, the present invention provides the application of the aforementioned photocurable release agent, or the photocurable release agent obtained by the aforementioned preparation method, in the preparation of release films.

[0025] In a seventh aspect, the present invention provides a release film obtained by photocuring the aforementioned photocurable release agent.

[0026] Eighthly, the present invention provides a method for preparing a release film, wherein a photocurable release agent is coated onto a polyester film and cured under net ultraviolet light.

[0027] Ninthly, the present invention provides the application of the release film described above, or the release film obtained by the preparation method, in the preparation of daily necessities.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. This invention uses fewer types of raw materials, and the synthesized acrylate-modified silicone oil has a simple molecular structure and does not contain functional groups with special structures. This invention uses dehydrating agents such as 4A molecular sieve as raw materials to synthesize high-viscosity silicone oil with high acrylate content.

[0030] 2. This invention uses a one-step synthesis method to directly obtain acrylate-modified silicone oil with adjustable viscosity and acrylate content, saving synthesis time and effectively reducing the impact of batch instability.

[0031] 3. The present invention performs distillation purification at 85-90℃, which reduces the risk of silicone oil self-polymerization during the purification process.

[0032] 4. The acrylate-modified silicone oil of this invention can be compounded with commercially available conventional photoinitiators. After UV curing, the release film formed has stable release force and a residual rate of 85%-90%, and can be widely used in die-cutting, labeling, hygiene products, tapes, waterproof membranes and other fields. Attached Figure Description

[0033] Figure 1 This invention relates to the preparation process and reaction formula of acrylate-modified silicone oil. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Example 1:

[0036] Preparation of acrylate-modified silicone oil: 250g of a dimethylcyclosiloxane mixture (DMC, chemical formula [(CH3)2SiO]5, commercially available) and 3g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 30℃, and after stabilization, 1.25mL of trifluoromethanesulfonic acid (density 1.696g / mL) was added. The mixture was stirred for two hours, followed by the addition of 70g of 4A molecular sieve. Then, 42g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise to the reaction flask. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was distilled using a short-path distillation apparatus under a vacuum of 5-12 Pa and a temperature of 85℃ to obtain acrylate-modified silicone oil (acrylate content approximately 12mol%). The preparation process and reaction formula of the acrylate-modified silicone oil of this invention are as follows: Figure 1 As shown.

[0037] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Example 1 was 512 mPa·s.

[0038] Example 2:

[0039] The acrylate-modified silicone oil prepared in Example 1 and photoinitiator 184 (CAS No. 947-19-3) were mixed at a mass ratio of 100:1.5 to obtain a photocurable release agent. Each 3g represents one part by mass.

[0040] Example 3:

[0041] The photocurable release agent prepared in Example 2, with a thickness of about 1 μm, was coated onto a PET film using a No. 0 wire rod. The film was then cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0042] Example 4:

[0043] Preparation of acrylate-modified silicone oil: 500g of a dimethylcyclosiloxane mixture and 3g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 35℃, and after the temperature stabilized, 1mL of trifluoromethanesulfonic acid was added. The mixture was stirred for two hours, followed by the addition of 60g of anhydrous sodium sulfate. Then, 36g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise to the reaction flask. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was then distilled using a short-path distillation apparatus under a vacuum of 5–12 Pa and a temperature of 90℃ to obtain acrylate-modified silicone oil (acrylate content approximately 4 mol%).

[0044] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Example 4 was 1693 mPa·s.

[0045] Example 5:

[0046] The acrylate-modified silicone oil prepared in Example 4 and photoinitiator 1173 (CAS No. 7473-98-5) were mixed at a mass ratio of 100:1.8 to obtain a photocurable release agent. Each 5g represents one part by mass.

[0047] Example 6:

[0048] The photocurable release agent prepared in Example 5, with a thickness of about 1 μm, was coated onto a PET film using a No. 0 wire rod. The film was then cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0049] Example 7:

[0050] Preparation of acrylate-modified silicone oil: 500g of a dimethylcyclosiloxane mixture and 3.5g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 40℃, and after the temperature stabilized, 2.5mL of trifluoromethanesulfonic acid was added. The mixture was stirred for two hours, followed by the addition of 150g of anhydrous calcium chloride. Then, 90g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise to the reaction flask. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was distilled using a short-path distillation apparatus under a vacuum of 5–12 Pa and a temperature of 85℃ to obtain acrylate-modified silicone oil (acrylate content approximately 13 mol%). Each 6g represents one part by mass.

[0051] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Example 7 was 1771 mPa·s.

[0052] Example 8:

[0053] The acrylate-modified silicone oil prepared in Example 7, photoinitiator 1173, and photoinitiator 184 were mixed at a mass ratio of 100:1.2:0.6 to obtain a photocurable release agent.

[0054] Example 9:

[0055] The photocurable release agent prepared in Example 8, with a thickness of about 1 μm, was coated onto a PET film using a No. 0 wire rod. The film was then cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0056] Example 10:

[0057] Preparation of acrylate-modified silicone oil: 500g of a mixture of dimethylcyclosiloxanes and 5g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 45℃, and after the temperature stabilized, 3.5mL of trifluoromethanesulfonic acid was added. The mixture was stirred for two hours, followed by the addition of 160g of 4A molecular sieve. Then, 80g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise to the reaction flask. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was then distilled using a short-path distillation apparatus under a vacuum of 5–12 Pa and a temperature of 85℃ to obtain acrylate-modified silicone oil (acrylate content approximately 12 mol%).

[0058] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Example 10 was 287 mPa·s.

[0059] Example 11:

[0060] The acrylate-modified silicone oil prepared in Example 10 and photoinitiator 1173 were mixed at a mass ratio of 100:1.5 to obtain a photocurable release agent. Each 6g represents one part by mass.

[0061] Example 12:

[0062] The photocurable release agent prepared in Example 11 was coated onto a PET film with a thickness of about 1 μm using a No. 0 wire rod, and then cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0063] Comparative Example 1:

[0064] Preparation of acrylate-modified silicone oil: 500g of a dimethylcyclosiloxane mixture and 3g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 35℃, and after the temperature stabilized, 1mL of trifluoromethanesulfonic acid was added. The mixture was stirred for two hours, and then 36g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was distilled using a short-path distillation apparatus at 5–12 Pa and 85℃ to obtain acrylate-modified silicone oil.

[0065] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Comparative Example 1 was 50 mPa·s.

[0066] Comparative Example 2:

[0067] The acrylate-modified silicone oil prepared in Comparative Example 1 and photoinitiator 1173 were mixed at a mass ratio of 100:1.8 to obtain a photocurable release agent. Each 5g represents one part by mass.

[0068] Comparative Example 3:

[0069] The photocurable release agent prepared in Comparative Example 2 was coated onto a PET film with a thickness of about 1 μm using a No. 0 wire rod. Then, the film was cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain the release film.

[0070] Comparative Example 4:

[0071] Preparation of acrylate-modified silicone oil: 500g of a dimethylcyclosiloxane mixture and 3g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 35℃, and after the temperature stabilized, 1mL of trifluoromethanesulfonic acid was added. The mixture was stirred for two hours, and then 80g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was distilled using a short-path distillation apparatus under a vacuum of 5–12 Pa and a temperature of 85℃ to obtain acrylate-modified silicone oil.

[0072] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Comparative Example 4 was 52 mPa·s.

[0073] Comparative Example 5:

[0074] The acrylate-modified silicone oil prepared in Comparative Example 4 and photoinitiator 1173 were mixed at a mass ratio of 100:1.8 to obtain a photocurable release agent.

[0075] Comparative Example 6:

[0076] The photocurable release agent prepared in Comparative Example 5 was coated onto a PET film with a thickness of about 1 μm using a No. 0 wire rod. Then, it was cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0077] Comparative Example 7:

[0078] Preparation of acrylate-modified silicone oil: 500g of a dimethylcyclosiloxane mixture and 1g of hexamethyldisiloxane were added to a reaction flask. The temperature was raised to 35℃, and after the temperature stabilized, 1mL of trifluoromethanesulfonic acid was added. The mixture was stirred for two hours, and then 36g of 3-(diethoxymethylsilyl)propyl 2-acrylate was added dropwise. After the addition was complete, the mixture was stirred for 10 hours. Anhydrous sodium carbonate was added for neutralization, and the mixture was filtered. The filtered silicone oil was distilled using a short-path distillation apparatus under a vacuum of 5–12 Pa and a temperature of 85℃ to obtain acrylate-modified silicone oil.

[0079] According to the viscometer test, the viscosity of the acrylate-modified silicone oil prepared in Comparative Example 7 was 80 mPa·s.

[0080] Comparative Example 8:

[0081] The acrylate-modified silicone oil prepared in Comparative Example 7 and photoinitiator 1173 were mixed at a mass ratio of 100:1.8 to obtain a photocurable release agent.

[0082] Comparative Example 9:

[0083] The photocurable release agent prepared in Comparative Example 8 was coated onto a PET film with a thickness of about 1 μm using a No. 0 wire rod. Then, it was cured by irradiation with a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0084] The hardness of the release films prepared in Examples 3, 6, 9, 12 and Comparative Examples 3, 6, 9 was tested using a pencil carriage hardness tester; the performance of the release films in Examples 1-4 and Comparative Examples 1-3 was tested according to GBT25256-2010, and the results are shown in Table 1.

[0085] Table 1. Hardness and performance test results of release films prepared in Examples 3, 6, 9, 12 and Comparative Examples 3, 6, 9.

[0086]

[0087] As shown in Table 1, the release agent prepared using the acrylate-modified silicone oil of this invention, after curing, exhibits a release force of 3–14 cN / 25 mm at 20 min, 5–18 cN / 25 mm at 20 h, and 3–20 cN / 25 mm at aging. The residual rate is 85%–90%, and the hardness is HB-B. Compared to Examples 3, 6, 9, and 12, the release films of Comparative Examples 3, 6, and 9 without the addition of a dehydrating agent have lower residual rates and lower hardness. The release films obtained in Comparative Examples 1–3 have a hardness less than 6B.

[0088] The test results of the release films prepared in Example 6 and Comparative Example 6 show that without the addition of a dehydrating agent, the viscosity of the acrylate-modified silicone oil is greatly reduced, and the residual rate and hardness of the release film are reduced.

[0089] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0090] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An acrylate-modified silicone oil, characterized in that, It contains the following raw materials in parts by weight: 5-15 parts of 3-(diethoxymethylsilyl)propyl 2-acrylate, 80-100 parts of a mixture of dimethylcyclosiloxanes, 0.06-1 part of hexamethyldisiloxane, 0.03-1 part of an acid solution, and 10-30 parts of a dehydrating agent; The acid solution is trifluoromethanesulfonic acid or sulfuric acid; The dehydrating agent is 4A molecular sieve, anhydrous magnesium sulfate, anhydrous calcium chloride, or anhydrous sodium sulfate; The preparation method of the acrylate-modified silicone oil includes the following steps: Weigh out a mixture of dimethylcyclosiloxane and hexamethyldisiloxane, heat it, and after the temperature stabilizes, add an acid solution, stir evenly, add a dehydrating agent, add dropwise 3-(diethoxymethylsilyl)propyl 2-acrylate, stir, adjust the pH value to neutral, filter, and distill at low temperature to obtain acrylate-modified silicone oil.

2. The acrylate-modified silicone oil according to claim 1, characterized in that, The temperature is raised to 30–60°C.

3. The acrylate-modified silicone oil as described in claim 1, characterized in that, The conditions for the low-temperature distillation are: vacuum degree 5-12 Pa and temperature 85-90℃.

4. The application of the acrylate-modified silicone oil as described in claim 1 in the preparation of photocurable release agents.

5. A light-curing release agent, characterized in that, It contains the following raw materials in parts by weight: 100 parts of acrylate-modified silicone oil as described in claim 1, and 1 to 2 parts of photoinitiator.

6. The photocurable release agent as described in claim 5, characterized in that, The photoinitiator is photoinitiator 1173 and / or photoinitiator 184.

7. The application of the photocurable release agent as described in claim 5 in the preparation of release film.

8. The method for preparing a photocurable release agent as described in claim 5, characterized in that, Acrylic-modified silicone oil is mixed with a photoinitiator to obtain a photocurable release agent.

9. The application of the photocurable release agent obtained by the preparation method described in claim 8 in the preparation of release films.

10. A release film, characterized in that, It is obtained by photocuring with the photocurable release agent as described in claim 5.

11. The application of the release film as described in claim 10 in the preparation of daily necessities.

12. The method for preparing a release film as described in claim 10, characterized in that, The release agent is coated onto a polyester film and then cured with ultraviolet light.

13. The application of the release film obtained by the preparation method as described in claim 12 in the preparation of daily necessities.

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