Acrylate modified silicone oil, preparation method and application of acrylate modified silicone oil in preparation of photocuring release agent

Abstract

The invention relates to acrylate modified silicone oil, a preparation method and application of the acrylate modified silicone oil in preparation of a photocuring release agent. Belongs to the technical field of organosilicone. The acrylate modified silicone oil is prepared from the following raw materials in parts by mass: 5 to 15 parts of 2-acrylic acid 3-(diethoxymethylsilyl) propyl ester, 80 to 100 parts of a dimethyl cyclosiloxane mixture, 0.06 to 1 part of hexamethyldisiloxane, 0.03 to 1 part of an acid solution and 10 to 30 parts of a dehydrating agent. The used raw materials are few in variety, and the synthesized acrylate modified silicone oil is simple in molecular structure and does not contain functional groups with special structures; the high-viscosity silicone oil with high acrylate content can be synthesized by adopting the 4A molecular sieve and other dehydrating agents in the raw materials.

Description

Technical Field

[0001] The present application belongs to the field of organic silicon technology, and particularly relates to an acrylate-modified silicone oil, a preparation method and application thereof in the preparation of a light-curing release agent. Background Art

[0002] Release agent, also commonly known as isolation agent, is a low surface energy polymer coated on the surface of the release film. According to the chemical composition, release agents are mainly divided into non-silicone release agents, silicone release agents and fluorosilicone release agents. Among them, the most commonly used type of release agent is silicone release agent. According to different reaction mechanisms, silicone release agents are mainly divided into three types: addition type, condensation type, and radiation curing type, and radiation curing type includes UV light curing and electron beam irradiation curing.

[0003] Addition-type silicone release agents have stable performance, will not release small molecules during the reaction process, have fast reaction speed, and high production efficiency. In addition to solvent-type release agents, solvent-free and emulsion-type release agents have been developed, which reduce environmental pollution and reduce the occurrence of dangerous situations. Therefore, addition-type silicone release agents are currently the most widely used type of release agents. However, addition-type silicone release agents need to be coated at a higher temperature, and are not suitable for some substrates with poor temperature resistance, so their application is subject to certain restrictions.

[0004] UV light-curing release agents appeared relatively late. They do not use heating to cure into films, but require UV light of a certain wavelength to crosslink and cure. Compared with addition-type silicone release agents, UV light-curing silicone release agents have the following advantages: (1) The reaction process does not require heating, and is suitable for substrates with poor heat resistance such as PP and PE; (2) It does not contain organic solvents, is environmentally friendly, and does not have safety hazards such as fire and explosion during storage, transportation, and production and processing; (3) The reaction speed is fast and can be completed within a few seconds, greatly improving production efficiency; (4) UV light-curing 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 need to be heated during the coating process, only UV light irradiation is required, so the energy consumption is low. Although UV light-curing silicone release agents have many advantages in performance and can basically replace traditional condensation-type and addition-type silicone release agents, they have not been fully accepted by users and have not been popularized in the market. The main reasons are high prices and complex molecular structures.

[0005] The main components of UV light-curing silicone release agent are polysiloxane modified with special functional groups and photoinitiators with special structures. The product has high technical content and the corresponding production process is relatively complicated. For example, the patent with announcement number CN110183664B discloses a preparation method and application of UV light-curing methacrylate silicone oil. The patent first synthesizes a methacrylate structure organic substance containing a mercapto structure. Secondly, it reacts with terminal epoxy polymethylsiloxane. Under the catalysis of organic base, the mercapto group efficiently and quickly performs a ring-opening click chemical reaction on propylene oxide to prepare terminal methacrylate polymethylsiloxane (PSi-MMA). The whole reaction is carried out in two steps, and many types of raw materials are used.

[0006] At present, the main light-curing release agent products on the market all adopt a free radical curing mode, which relies on the acrylate functional group to promote curing under the photoinitiator. Due to the presence of the acrylate functional group, the release agent cannot be heated, which increases the difficulty of the purification step in the production process. Although there are patent reports that silicone oil can be heated to 140 degrees for vacuum distillation purification, it has been concluded in practice that at this temperature, when the acrylate content is too high, it is very likely to cause acrylate self-polymerization, resulting in gelation.

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

[0008] In view of the defects existing in the above-mentioned prior art, in order to solve the problems of complex molecular structure and cumbersome preparation process of photocurable release agent, the purpose of the present invention is to design and provide an acrylate-modified silicone oil, a preparation method and its application in the preparation of photocurable release agent. The present invention uses a small number of raw materials, and the synthesized acrylate-modified silicone oil has a simple molecular structure and does not contain functional groups of special structures. The present invention can synthesize high-viscosity silicone oil containing a high acrylate content by using a dehydrating agent such as 4A molecular sieve in the raw materials.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] On the one hand, the present invention provides an acrylate-modified silicone oil, comprising the following raw materials in parts by weight: 5 to 15 parts of 3-(diethoxymethylsilyl)propyl 2-acrylate, 80 to 100 parts of a dimethylcyclosiloxane mixture, 0.06 to 1 part of hexamethyldisiloxane, 0.03 to 1 part of an acid solution, and 10 to 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. In the present invention, adding 4A molecular sieve to the raw material can synthesize high-viscosity silicone oil containing high acrylate content. If the molecular sieve is not added, the viscosity of the silicone oil will decrease as the acrylate content increases.

[0013] The acrylate-modified silicone oil has a structural formula as shown in the following formula I:

[0014]

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

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

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

[0018] Preferably, the heating is to 30-60°C;

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

[0020] In a third aspect, the present invention provides the acrylate-modified silicone oil, or the use of the acrylate-modified silicone oil obtained by the preparation method in the preparation of a photocurable release agent.

[0021] In a fourth aspect, the present invention provides a photocurable release agent, comprising the following raw materials in parts by weight: 100 parts of the acrylate-modified silicone oil as described in claim 1 or 2, and 1 to 2 parts of a photoinitiator;

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

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

[0024] In a sixth aspect, the present invention provides the photocurable release agent, or the use of the photocurable release agent obtained by the preparation method in preparing a release film.

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

[0026] In an eighth aspect, the present invention provides a method for preparing the release film, which is obtained by coating a photocurable release agent on a polyester film and then curing the film with ultraviolet light.

[0027] In a ninth aspect, the present invention provides the release film, or the use of 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. The present invention uses a small number of raw materials, and the synthesized acrylate-modified silicone oil has a simple molecular structure and does not contain functional groups of special structures; the present invention uses a dehydrating agent such as 4A molecular sieve as a raw material to synthesize a high-viscosity silicone oil containing a high acrylate content.

[0030] 2. The present invention adopts a one-step synthesis method to directly obtain acrylate-modified silicone oil with adjustable viscosity and acrylate content, which saves synthesis time and effectively reduces the impact of batch instability.

[0031] 3. The present invention performs distillation purification at 85-90° C., thereby reducing the risk of silicone oil self-polymerization during the purification process.

[0032] 4. The acrylate-modified silicone oil of the present invention can be compounded with conventional commercially available photoinitiators. The release force of the release film formed after UV curing is stable, and the residual rate is 85%-90%. It can be widely used in die-cutting, labels, sanitary products, tapes, waterproof rolls and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention provides a preparation process and reaction formula for the acrylate-modified silicone oil. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] Embodiment 1:

[0036] Preparation of acrylate-modified silicone oil: Add 250g of dimethylcyclosiloxane mixture (DMC, chemical formula [(CH3)2SiO]5, purchased commercially) and 3g of hexamethyldisiloxane into a reaction bottle, raise the temperature to 30°C, add 1.25mL of trifluoromethanesulfonic acid (density 1.696g / mL) after the temperature stabilizes, stir for two hours, add 70g of 4A molecular sieves, and then drop 42g of 2-acrylic acid 3-(diethoxymethylsilyl)propyl ester into the reaction bottle. After the addition is complete, stir for 10 hours, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device under vacuum of 5 to 12Pa and a temperature of 85°C to obtain acrylate-modified silicone oil (acrylate content is about 12 mol%). The preparation process and reaction formula of the acrylate-modified silicone oil of the present invention are as follows: Figure 1 shown.

[0037] The viscosity of the acrylate-modified silicone oil prepared in Example 1 was 512 mPa·s as measured by a viscometer.

[0038] Embodiment 2:

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

[0040] Embodiment 3:

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

[0042] Embodiment 4:

[0043] Preparation of acrylate-modified silicone oil: Add 500g of dimethylcyclosiloxane mixture and 3g of hexamethyldisiloxane to a reaction bottle, raise the temperature to 35°C, add 1mL of trifluoromethanesulfonic acid after the temperature stabilizes, stir for two hours, add 60g of anhydrous sodium sulfate, and then drop 36g of 2-acrylic acid 3-(diethoxymethylsilyl)propyl ester into the reaction bottle, stir for 10 hours after the dropwise addition is completed, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device under vacuum of 5-12Pa and a temperature of 90°C to obtain acrylate-modified silicone oil (acrylate content is about 4mol%).

[0044] Viscometer test showed that the viscosity of the acrylate-modified silicone oil prepared in Example 4 was 1693 mPa·s.

[0045] Embodiment 5:

[0046] The acrylate-modified silicone oil prepared in Example 4 and the photoinitiator 1173 (CAS No. 7473-98-5) were mixed in a mass ratio of 100:1.8 to obtain a light-curable release agent, wherein 5 g is one mass part.

[0047] Embodiment 6:

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

[0049] Embodiment 7:

[0050] Preparation of acrylate-modified silicone oil: Add 500g of dimethylcyclosiloxane mixture and 3.5g of hexamethyldisiloxane to a reaction bottle, raise the temperature to 40°C, add 2.5mL of trifluoromethanesulfonic acid after the temperature stabilizes, stir for two hours, add 150g of anhydrous calcium chloride, and then drop 90g of 2-acrylic acid 3-(diethoxymethylsilyl)propyl ester into the reaction bottle, stir for 10 hours after the addition is completed, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device under vacuum 5-12Pa and temperature 85°C to obtain acrylate-modified silicone oil (acrylate content is about 13mol%). Among them, each 6g is one mass part.

[0051] Viscometer test showed that the viscosity of the acrylate-modified silicone oil prepared in Example 7 was 1771 mPa·s.

[0052] Embodiment 8:

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

[0054] Embodiment 9:

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

[0056] Embodiment 10:

[0057] Preparation of acrylate-modified silicone oil: Add 500g of dimethylcyclosiloxane mixture and 5g of hexamethyldisiloxane to a reaction bottle, raise the temperature to 45°C, add 3.5mL of trifluoromethanesulfonic acid after the temperature stabilizes, stir for two hours, add 160g of 4A molecular sieve, and then drop 80g of 2-acrylic acid 3-(diethoxymethylsilyl)propyl ester into the reaction bottle, stir for 10 hours after the dropwise addition is completed, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device under the conditions of a vacuum degree of 5-12Pa and a temperature of 85°C to obtain acrylate-modified silicone oil (acrylate content is about 12mol%).

[0058] The viscosity of the acrylate-modified silicone oil prepared in Example 10 was 287 mPa·s as measured by a viscometer.

[0059] Embodiment 11:

[0060] The acrylate-modified silicone oil prepared in Example 10 and the photoinitiator 1173 were mixed in a mass ratio of 100:1.5 to obtain a light-curable release agent, wherein 6 g is one mass part.

[0061] Embodiment 12:

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

[0063] Comparative Example 1:

[0064] Preparation of acrylate-modified silicone oil: Add 500g of dimethylcyclosiloxane mixture and 3g of hexamethyldisiloxane to a reaction bottle, raise the temperature to 35°C, add 1mL of trifluoromethanesulfonic acid after the temperature stabilizes, stir for two hours, start to drop 36g of 2-acrylate 3-(diethoxymethylsilyl)propyl ester, stir for 10 hours after the dropwise addition is completed, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device at 5-12Pa and 85°C to obtain acrylate-modified silicone oil.

[0065] Viscometer test showed that 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 the photoinitiator 1173 were mixed in a mass ratio of 100:1.8 to obtain a light-curable release agent, wherein 5 g is one mass part.

[0068] Comparative Example 3:

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

[0070] Comparative Example 4:

[0071] Preparation of acrylate-modified silicone oil: Add 500g of dimethylcyclosiloxane mixture and 3g of hexamethyldisiloxane to a reaction bottle, raise the temperature to 35°C, add 1mL of trifluoromethanesulfonic acid after the temperature stabilizes, stir for two hours, start to drop 80g of 2-acrylate 3-(diethoxymethylsilyl)propyl ester, stir for 10 hours after the dropwise addition is completed, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device at a vacuum degree of 5-12Pa and a temperature of 85°C to obtain acrylate-modified silicone oil.

[0072] Viscometer test showed that 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 the photoinitiator 1173 were mixed in 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 on the PET film with a thickness of about 1 μm using a No. 0 wire rod, and then irradiated and cured using a mercury lamp under nitrogen (energy 7666 mJ) to obtain a release film.

[0077] Comparative Example 7:

[0078] Preparation of acrylate-modified silicone oil: Add 500g of dimethylcyclosiloxane mixture and 1g of hexamethyldisiloxane to a reaction bottle, raise the temperature to 35°C, add 1mL of trifluoromethanesulfonic acid after the temperature stabilizes, stir for two hours, start to drop 36g of 2-acrylate 3-(diethoxymethylsilyl)propyl ester, stir for 10 hours after the dropwise addition is completed, add anhydrous sodium carbonate for neutralization, and filter. The filtered silicone oil is distilled using a short-path distillation device at a vacuum degree of 5-12Pa and a temperature of 85°C to obtain acrylate-modified silicone oil.

[0079] Viscometer test showed that 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 the photoinitiator 1173 were mixed in 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 on the PET film with a thickness of about 1 μm using a No. 0 wire rod, and then irradiated and cured using 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 trolley hardness tester. The performance of the release films of Examples 1-4 and Comparative Examples 1-3 was tested in accordance with GBT25256-2010. 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 can be seen from Table 1, after curing, the release agent prepared by using the acrylate modified silicone oil prepared by the present invention has a release force of 3-14 cN / 25mm for 20 minutes, a release force of 5-18 cN / 25mm for 20 hours, an aging release force of 3-20 cN / 25mm, a residual rate of 85%-90%, and a hardness of HB-B grade. Compared with Examples 3, 6, 9, and 12, the residual rate and hardness of the release films of Comparative Examples 3, 6, and 9 without adding a dehydrating agent are both lower, and the hardness of the release films obtained by Comparative Examples 1 to Comparative Examples 3 is less than 6B.

[0088] From the test results of the release films prepared in Example 6 and Comparative Example 6, it can be seen that without adding a dehydrating agent, the viscosity of the prepared 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 "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element. In the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically specified.

[0090] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. An acrylate-modified silicone oil, characterized in that: The method comprises the following raw materials in parts by weight: 5 to 15 parts of 3-(diethoxymethylsilyl)propyl 2-acrylate, 80 to 100 parts of a dimethylcyclosiloxane mixture, 0.06 to 1 part of hexamethyldisiloxane, 0.03 to 1 part of an acid solution, and 10 to 30 parts of a dehydrating agent; Preferably, the acid solution is trifluoromethanesulfonic acid or sulfuric acid; Preferably, the dehydrating agent is 4A molecular sieve, anhydrous magnesium sulfate, anhydrous calcium chloride or anhydrous sodium sulfate.

2. An acrylate-modified silicone oil as claimed in claim 1, characterized in that: The structural formula of the acrylate-modified silicone oil is shown in Formula I below: Wherein, n is an integer between 100 and 250; o is an integer between 5 and 15.

3. The method for preparing an acrylate-modified silicone oil according to claim 1 or 2, characterized in that: The following steps are involved: Weigh a dimethylcyclosiloxane mixture and hexamethyldisiloxane, mix them, heat them, add an acid solution after the temperature stabilizes, stir them evenly, add a dehydrating agent, dropwise add 2-acrylate 3-(diethoxymethylsilyl)propyl ester, stir, adjust the pH value to neutral, filter, and distill at low temperature to obtain acrylate-modified silicone oil; Preferably, the heating is to 30-60°C; Preferably, the conditions for the low-temperature distillation are: vacuum degree 5-12 Pa, temperature 85-90°C.

4. Use of the acrylate-modified silicone oil according to claim 1 or 2, or the acrylate-modified silicone oil obtained by the preparation method according to claim 3 in the preparation of a light-curing release agent.

5. A photocurable release agent, characterized in that: The method comprises the following raw materials in parts by weight: 100 parts of the acrylate-modified silicone oil as claimed in claim 1 or 2, and 1 to 2 parts of a photoinitiator; Preferably, the photoinitiator is photoinitiator 1173 and / or photoinitiator 184.

6. The method for preparing a light-curing release agent according to claim 5, characterized in that: The acrylate-modified silicone oil is mixed with a photoinitiator to obtain a light-curing release agent.

7. Use of the photocurable release agent according to claim 5, or the photocurable release agent obtained by the preparation method according to claim 6 in preparing a release film.

8. A release film, characterized in that: The method is obtained by photocuring the photocurable release agent as claimed in claim 5.

9. The method for preparing a release film according to claim 8, characterized in that: The photocurable release agent is coated on the polyester film and then cured by ultraviolet light.

10. Use of the release film according to claim 8, or the release film obtained by the preparation method according to claim 9 in preparing daily necessities.

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