CN118834337A - Organosilicon modified hydroxy acrylic resin and preparation method thereof - Google Patents

Abstract

The application relates to the field of materials, and particularly discloses an organosilicon modified hydroxy acrylic resin and a preparation method thereof. The preparation method comprises the following steps: and (3) mixing and dissolving silane coupling agents with different reaction groups in water, mixing acrylic ester, acrylic acid, styrene and the silane coupling agents with double bonds to obtain a mixed material, mixing the mixed material with the organosilicon alcohol, dripping the mixed material into an organic solution containing an initiator, and carrying out free radical polymerization reaction to obtain the organosilicon modified hydroxy acrylic resin. The application obtains the organic silanol structure through dehydration condensation of silane coupling agents with different reactive groups. The organosilicon alcohol structure can be used as a bridge molecule in the subsequent free radical polymerization, so that the interface bonding strength between the obtained organosilicon modified hydroxy acrylic resin and a low-surface-energy substrate is enhanced, and the overall performance of the composite material is improved.

Description

A kind of organosilicon modified hydroxy acrylic resin and preparation method thereof

Technical Field

The present application relates to the field of materials, and more specifically, to an organosilicon-modified hydroxy acrylic resin and a preparation method thereof.

Background Art

Hydroxylated acrylic resins are widely used in the coatings field due to their superior adhesion to various substrates, high transparency, oil resistance, numerous monomers, simple process and low cost. However, traditional hydroxylated acrylic resins have poor adhesion when applied to substrates with low surface energy, which limits their application scope.

At present, common methods to improve the adhesion of hydroxylated acrylic resins on low surface energy substrates include substrate pretreatment (such as corona, flame, plasma treatment, etc.) and the use of adhesion promoters. However, these methods often have problems such as complex processes, high costs, or affect coating performance.

In addition, there are also processes in the prior art that use silicone to modify hydroxy acrylic resins. These improvements are helpful in improving the adhesion of commonly used substrates, but for some substrates that are difficult to adhere to on the market, such as PP, PTFE, PPO, PBT and other substrates with very low surface energy, the adhesion is very poor. These low surface energy materials have the advantages of light weight, durability, chemical resistance, temperature resistance, high mechanical strength, etc., and are increasingly widely used in the fields of machinery, automobiles, electronics, etc. Therefore, it is necessary to develop silicone-modified acrylic resins with good adhesion to these low surface energy materials.

Summary of the invention

In order to solve the problem that acrylic resin has poor adhesion to substrates with very low surface energy, the present application provides a silicone-modified hydroxy acrylic resin and a preparation method thereof.

This application adopts the following technical solutions:

A method for preparing a silicone-modified hydroxy acrylic resin comprises the following steps:

Step S1: Mix and dissolve silane coupling agents with different reactive groups in water, heat to 60-100° C., and perform hydrolysis and condensation reaction for 3-6 hours under the action of a catalyst to obtain an organosilanol;

Step S2: Mix acrylate, acrylic acid, styrene and a silane coupling agent with a double bond to obtain a mixture, mix the mixture with the organosilanol, add the mixture dropwise to an organic solution containing an initiator, and perform a free radical polymerization reaction at 90-110° C. for 2-4 hours to obtain an organosilicon-modified hydroxy acrylic resin.

In the above technical solution, when a silane coupling agent with different reactive groups is heated and a catalyst is present, the hydrolyzable group (such as alkoxy) in the silane coupling agent undergoes a hydrolysis reaction to generate a silanol group, and then the silanol groups form a silicon-oxygen bond through a dehydration condensation reaction, thereby obtaining an organic silanol structure. In the polymerization reaction of this organic silanol structure with acrylate, styrene and silane coupling agent, these monomers are interconnected through a free radical polymerization reaction to form a copolymer with special properties, namely, an organic silicon-modified hydroxy acrylic resin. The organic silanol and silane coupling agent can be used as bridge molecules to enhance the interfacial bonding strength between the polymer and the low surface energy substrate, thereby improving the overall performance of the composite material.

Further, in the hydrolysis condensation reaction, there are at least two kinds of silane coupling agents; the silane coupling agents are selected from: vinyl trimethoxysilane, vinyl triethoxysilane, tris-isocyanate propyl trimethoxysilane, tris-isocyanate propyl triethoxysilane, phenyl triethoxysilane, phenyl trimethoxysilane, allyl trimethoxysilane, allyl triethoxysilane, methacryloxypropyl trimethoxysilane, methacryloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl triethoxysilane, etc., preferably vinyl trimethoxysilane, methacryloxypropyl trimethoxysilane, allyl trimethoxysilane and phenyl trimethoxysilane.

Preferably, in the hydrolysis condensation reaction, the silane coupling agent is selected from the following combination:

Vinyl trimethoxysilane, methacryloxypropyl trimethoxysilane and isocyanate propyl trimethoxysilane, preferably, the mass ratio of the above three silane coupling agents is 1:(0.7-0.9):(0.3-0.4);

Or, vinyl trimethoxysilane, phenyl trimethoxysilane and isocyanate propyl trimethoxysilane, preferably, the mass ratio of the above three silane coupling agents is 1: (0.6-0.7): (0.3-0.4);

Or, methacryloxypropyl trimethoxysilane, 3-glycidyloxypropyl trimethoxysilane and phenylmethyldimethoxysilane, the mass ratio of the above three silane coupling agents is 1:(0.2-0.3):(0.15-0.20);

Or, allyl trimethoxysilane, 3-glycidyloxypropyl trimethoxysilane, phenyl triethoxysilane, isocyanate propyl triethoxysilane, the mass ratio of the above four silane coupling agents is 1:(1.2-1.6):(2-3):(0.3-0.7).

Furthermore, in the hydrolysis condensation reaction, the catalyst is selected from any one of concentrated hydrochloric acid, concentrated sulfuric acid, sodium hydroxide, potassium hydroxide and p-toluenesulfonic acid.

Furthermore, in the hydrolysis condensation reaction, when the catalyst is sodium hydroxide or potassium hydroxide, it also includes:

adding an acidic neutralizing agent to the reaction solution after the hydrolysis condensation reaction to carry out a neutralization reaction;

Preferably, the acidic neutralizing agent is hydrochloric acid;

Preferably, the conditions for the neutralization reaction are: reaction temperature 60-100° C., and reaction time 1-3 h.

Furthermore, in the free radical polymerization reaction, the mass ratio of the mixed material to the organosilanol is 1:0.1-0.3; preferably, the mass ratio is 1:0.2-0.3. If the content of organosilanol is too low, the adhesion to the substrate is insufficient, and if the content of organosilanol is too high, the synthesized acrylic resin will be turbid and have a short storage time, and may even gel during the reaction.

Preferably, in the mixed material, the mass ratio of the silane coupling agent to the acrylate, acrylic acid and styrene is 1:(10-13):(0.5-2):(0.3-6).

Furthermore, in the free radical polymerization reaction, the silane coupling agent with double bonds is methacryloxypropyl tris(trimethylsiloxy)silane. The double bonds of the silane coupling agent undergo free radical polymerization with the double bonds of the acrylate, and because its structure is similar to that of the organosilanol, the compatibility between the organosilanol and acrylic acid is improved, thereby contributing to the transparency and storage stability of the organosilicon-modified acrylic resin.

Furthermore, in the free radical polymerization reaction, the initiator is selected from any one of dibenzoyl peroxide, tert-amyl peroxy 2-ethylhexyl carbonate, azobisisobutyronitrile, azobisisoheptylnitrile and tert-butyl perbenzoate.

Preferably, in the free radical polymerization reaction, the amount of the initiator added is 1-4%. The inventors have found that the amount of the initiator will affect the performance of the final silicone-modified hydroxy acrylic resin. Specifically, when the amount of the initiator added exceeds 4%, the free radical concentration in the system will be too high, which will promote the occurrence of cross-linking and branching reactions, making the polymer structure complex, thereby affecting the performance of the polymer; and when the amount of the initiator added is less than 1%, the polymerization reaction rate is too slow and the reaction efficiency is low.

Further, in the free radical polymerization reaction, the organic solvent is one or more of ester, phenyl alkane, alcohol ether, and ketone solvents, wherein the ester solvent is one or more of methyl acetate, ethyl acetate, butyl acetate, tert-butyl acetate, propyl acetate, and ethyl butyrate; the phenyl alkane solvent is one or more of xylene, toluene, and ethylbenzene; the alcohol ether solvent is one or more of ethylene glycol methyl ether, ethylene glycol ethyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, dipropylene glycol methyl ether, etc.; the ketone solvent is one or more of acetone, acetophenone, cyclohexanone, etc., preferably methyl acetate, butyl acetate, xylene, ethylene glycol methyl ether, and acetone.

In a second aspect, the present application provides a silicone-modified hydroxy acrylic resin prepared by the above preparation method.

In summary, this application has the following beneficial effects:

1. The present application generates silanol groups by hydrolysis reaction of silane coupling agents with different reactive groups, and then forms silicon-oxygen bonds through dehydration condensation reaction between the silanol groups, thereby obtaining an organic silanol structure. This organic silanol structure can serve as a bridge molecule in the subsequent free radical polymerization, thereby enhancing the interfacial bonding strength between the obtained organic silicon-modified hydroxy acrylic resin and the low surface energy substrate, and improving the overall performance of the composite material.

2. The hydrolysis polymerization reaction process in the first step of the present application is simple, and does not require complicated post-processing steps. The obtained organosilanol has low viscosity and is suitable for subsequent free radical polymerization reactions;

3. The silane coupling agent and organosilanol used in the polymerization reaction contain different reactive groups, and the reactive groups contained in the acrylate are connected to each other through the free radical polymerization reaction to form a copolymer with special properties, which improves the adhesion to the substrate with low surface energy. The polymerization reaction is simple to operate, mild in reaction, and does not require excessive post-processing operations, which is suitable for industrial production.

DETAILED DESCRIPTION

The embodiments of the present invention will be described in detail below in conjunction with examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. The specific conditions not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

Example 1

This embodiment provides a silicone-modified hydroxy acrylic resin, and the preparation method thereof includes:

(1) Synthesis of organosilanol 1:

148.2 g of vinyltrimethoxysilane, 124.2 g of methacryloyloxypropyltrimethoxysilane, 51.3 g of isocyanatepropyltrimethoxysilane, 23.6 g of deionized water and 0.3 g of hydrochloric acid were added in sequence into a 500 ml four-necked flask, reacted at 60° C. for 3 hours, and then subjected to reduced pressure distillation at 80° C. to obtain 161 g of light yellow transparent organosilanol 1.

(2) Synthesis of silicone-modified hydroxy acrylic resin 1:

45 g of methyl acrylate, 25 g of butyl methacrylate, 15 g of hydroxyethyl acrylate, 5 g of methacrylic acid, 3 g of styrene, 7 g of methacryloyloxypropyl tris(trimethylsiloxy)silane and 20 g of organosilanol 1 were mixed, nitrogen was introduced at 90° C., and the mixture was added dropwise to a mixed solution of 1.6 g of dibenzoyl peroxide, 60 g of ethyl acetate and 60 g of xylene. The mixture was added dropwise for 3 hours, and the mixture was kept warm for reaction for 2 hours, then cooled to room temperature, filtered, and 235 g of organosilicon-modified acrylic resin 1 (solid content 58%) was obtained.

Example 2

This embodiment provides a silicone-modified hydroxy acrylic resin, and the preparation method thereof includes:

(1) Synthesis of organosilanol 2:

148.2 g of vinyltrimethoxysilane, 99 g of phenyltrimethoxysilane, 51.3 g of isocyanatepropyltrimethoxysilane, 23.6 g of deionized water and 0.32 g of hydrochloric acid were added in sequence into a 500 ml four-necked flask, reacted at 60° C. for 3 hours, and then subjected to reduced pressure distillation at 80° C. to obtain 164 g of light yellow transparent organosilanol 2.

(2) Synthesis of silicone-modified hydroxy acrylic resin 2:

After mixing 30g of isobornyl methacrylate, 30g of butyl methacrylate, 25g of hydroxyethyl methacrylate, 5g of acrylic acid, 3g of styrene, 7g of methacryloyloxypropyl tris(trimethylsiloxy)silane, and 30g of organosilanol 2, nitrogen was introduced at 90°C and the mixture was added dropwise to a mixed solution of 1.8g of dibenzoyl peroxide, 65g of ethyl acetate and 65g of xylene. The mixture was added dropwise for 3 hours, and the mixture was kept warm for reaction for 2 hours, then cooled to room temperature and filtered to obtain 211g of organosilicon-modified acrylic resin 2 (solid content 56%).

Example 3

This embodiment provides a silicone-modified hydroxy acrylic resin, and the preparation method thereof includes:

(1) Synthesis of organosilanol 3:

59 g of 3-glycidyloxypropyltrimethoxysilane, 248 g of methacryloxypropyltrimethoxysilane, 45 g of phenylmethyldimethoxysilane, 28 g of deionized water and 0.25 g of sodium hydroxide were added into a 500 ml four-necked flask in sequence, reacted at 60° C. for 3 hours, then 0.23 hydrochloric acid was added for neutralization reaction for 2 hours, and vacuum distillation was performed at 80° C. to obtain 246 g of light yellow transparent organosilanol 3.

(2) Synthesis of silicone-modified hydroxy acrylic resin 3:

After mixing 45g of methyl acrylate, 25g of butyl methacrylate, 5g of isocyanoethyl methacrylate, 5g of methacrylic acid, 13g of styrene, 7g of methacryloyloxypropyl tris(trimethylsiloxy)silane, and 25g of organosilanol 3, nitrogen was introduced at 110°C and the mixture was added dropwise to a mixed solution of 2.5g of tert-butyl perbenzoate, 60g of xylene and 65g of ethylene glycol methyl ether. The mixture was added dropwise for 3 hours, and the mixture was kept warm for reaction for 2 hours, cooled to room temperature, and the material was filtered to obtain 200g of organosilicon-modified acrylic resin 3 (with a solid content of 50%).

Example 4

This embodiment provides a silicone-modified hydroxy acrylic resin, and the preparation method thereof includes:

(1) Synthesis of organosilanol 4:

48 g of allyltrimethoxysilane 1, 71 g of 3-glycidyloxypropyltrimethoxysilane, 120 g of phenyltriethoxysilane, 25 g of isocyanatepropyltriethoxysilane, 9.7 g of deionized water, and 0.26 g of sulfuric acid were sequentially added into a 500 ml four-necked flask, reacted at 60° C. for 3 hours, and then subjected to reduced pressure distillation at 60° C. to obtain 132 g of light yellow transparent organosilanol 4.

(2) Synthesis of silicone-modified hydroxy acrylic resin 4:

20 g of methyl acrylate, 20 g of butyl methacrylate, 15 g of glycidyl acrylate, 10 g of methacrylic acid, 30 g of styrene, 5 g of methacryloyloxypropyl tris(trimethylsiloxy)silane and 30 g of organosilanol 4 were mixed, and nitrogen was introduced at 90°C. The mixture was added dropwise to a mixed solution of 3.25 g of azobisisobutyronitrile, 35 g of ethyl acetate and 95 g of cyclohexanone. The mixture was added dropwise for 3 hours. After the mixture was kept warm for reaction for 3 hours, the temperature was cooled to room temperature, and the material was filtered to obtain 123 g of organosilicon-modified acrylic resin 4 with a solid content of 60%.

Embodiment 5-7

This group of embodiments provides an organosilicon-modified hydroxy acrylic resin, and the preparation method thereof is different from that of Embodiment 1 in that: Embodiment 5: in the reaction of synthesizing organosiliconol, the heating temperature is 60° C. and the reaction time is 6 h;

Example 6: In the reaction of synthesizing organosilanol, the heating temperature is 80°C and the reaction time is 4h;

Example 7: In the reaction of synthesizing organosilanol, the heating temperature is 100°C and the reaction time is 3h.

Embodiment 8-9

This group of embodiments provides an organosilicon-modified hydroxy acrylic resin, and the preparation method thereof is different from that of Embodiment 3 in that: Embodiment 8: In the reaction of synthesizing organosiliconol, hydrochloric acid is added for neutralization reaction for 1 hour, and the reaction temperature is 100°C;

Example 9: In the reaction of synthesizing organosilanol, hydrochloric acid was added for neutralization reaction for 3 hours at a reaction temperature of 70°C;

Examples 9-10

This group of embodiments provides a silicone-modified hydroxy acrylic resin, and the preparation method thereof is different from that of Embodiment 1 in that: Embodiment 9: in the free radical polymerization reaction, the heating temperature is 90° C. and the reaction time is 4 h;

Example 10: In the free radical polymerization reaction, the heating temperature is 110°C and the reaction time is 2h;

Example 11: In the free radical polymerization reaction, the amount of organosilanol added is 10 g;

Example 12: In the free radical polymerization reaction, the amount of organosilanol added is 30 g.

Comparative Examples 1-4

This comparative example provides an acrylic resin, and its added materials are basically the same as those in Examples 1-4, specifically:

Comparative Example 1: 45 g of methyl acrylate, 35 g of butyl methacrylate, 15 g of hydroxyethyl acrylate, 5 g of methacrylic acid and 5 g of styrene were mixed, nitrogen was introduced at 90°C, and the mixture was added dropwise to a mixed solution of 1.6 g of dibenzoyl peroxide, 50 g of ethyl acetate and 50 g of xylene. The mixture was added dropwise for 3 hours, and the mixture was kept warm for 2 hours, cooled to room temperature, and the material was filtered to obtain 180 g of acrylic resin 1 with a solid content of 60%.

Comparative Example 2: 30 g of isobornyl methacrylate, 30 g of butyl methacrylate, 25 g of hydroxyethyl methacrylate, 5 g of acrylic acid and 10 g of styrene were mixed, nitrogen was introduced at 90°C, and the mixture was added dropwise to a mixed solution of 1.8 g of dibenzoyl peroxide, 50 g of ethyl acetate and 50 g of acetone. The mixture was added dropwise for 3 hours, and the mixture was kept warm for 2 hours, cooled to room temperature, and the material was filtered to obtain 160 g of acrylic resin 2 with a solid content of 65%.

Comparative Example 3: 45 g of methyl acrylate, 25 g of butyl methacrylate, 5 g of isocyanoethyl methacrylate, 5 g of methacrylic acid, 13 g of styrene and 2.5 g of tert-butyl perbenzoate were mixed, nitrogen was introduced at 110° C., and the mixture was added dropwise to a mixed solution of 2.5 g of tert-butyl perbenzoate, 100 g of xylene and 100 g of ethylene glycol methyl ether. The mixture was added dropwise for 3 hours. After the mixture was kept warm for 3 hours, it was cooled to room temperature and the material was filtered to obtain 396 g of acrylic resin 3 with a solid content of 53%.

Comparative Example 4: 20 g of methyl acrylate, 25 g of butyl methacrylate, 15 g of glycidyl acrylate, 10 g of methacrylic acid and 30 g of styrene were mixed, nitrogen was introduced at 90°C, and the mixture was added dropwise to a mixed solution of 2.5 g of azobisisobutyronitrile, 25 g of ethyl acetate and 75 g of cyclohexanone. The mixture was added dropwise for 3 hours. After the mixture was kept warm for 3 hours, it was cooled to room temperature and the material was filtered to obtain 150 g of acrylic resin 4 with a solid content of 55%.

Comparative Example 5

This comparative example provides an organosilicon-modified hydroxy acrylic resin, and its preparation method is different from that of Example 1 in that: in the free radical polymerization reaction, the amount of organosiliconol added is 30 g.

Comparative Example 6

This comparative example provides an organosilicon-modified hydroxy acrylic resin, and its preparation method is different from that of Example 1 in that: in the free radical polymerization reaction, the amount of organosiliconol added is 5 g.

Comparative Example 7

This comparative example provides a silicone-modified hydroxy acrylic resin, and its preparation method is different from that of Example 1 in that: in the free radical polymerization reaction, no methacryloxypropyl tris(trimethylsiloxy)silane is added, and the amount of hydroxyethyl acrylate added is 22 g.

Performance testing

Adhesion test using the 100-grid method:

The resins provided in Examples 1-4 and Comparative Examples 1-7 were respectively coated on the surfaces of PP, PPO, PBT and PA substrates in an area of 10cm*10cm and a thickness of 2cm. After drying, a grid was drawn on the surface of the substrate coated with the resin with a grid knife. Finally, the adhesion level was determined by the shedding of the coating. The adhesion decreased gradually from level 0 to level 5, with level 5 being the worst.

The results are shown in the following table:

It can be seen from the above table that, compared with the unmodified acrylic resins in Comparative Examples 1-4, the silicone-modified acrylic resins provided in Examples 1-4 of the present application have significantly improved adhesion to low surface energy substrates such as PP, PPO, PBT and PA.

At the same time, although the addition of organosilanol will change the adhesion of the acrylic resin during the free radical polymerization reaction, it is found through the comparison of Example 1 with Comparative Examples 7 and 8 that the amount of organosilanol added will significantly affect the adhesion of the acrylic resin. When too little organosilanol is added, the modification is incomplete, affecting the adhesion to the substrate; when too much organosilanol is added, the storage stability of the acrylic resin will be affected.

In addition, it can be seen from Comparative Example 9 that whether or not to add a silane coupling agent during the free radical polymerization reaction will further affect the adhesion of the organosilicon-modified acrylic resin. This is because the silane coupling agent has a siloxane group and a silanol active group, and its addition will increase the surface tension of the acrylic resin and significantly improve the adhesion to the substrate.

This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims (10)

1. A method for preparing a silicone-modified hydroxy acrylic resin, characterized in that it comprises: Silane coupling agents with different reactive groups are mixed and dissolved in water, heated to 60-100°C, and subjected to hydrolysis and condensation reaction for 3-6 hours under the action of a catalyst to obtain organosilanol; Acrylate, acrylic acid, styrene and a silane coupling agent with a double bond are mixed to obtain a mixture, the mixture is mixed with the organosilanol, and the mixture is added dropwise to an organic solution containing an initiator, and a free radical polymerization reaction is carried out at 90-110° C. for 2-4 hours to obtain an organosilicon-modified hydroxy acrylic resin. 2. The method for preparing a silicone-modified hydroxy acrylic resin according to claim 1, characterized in that, in the hydrolysis condensation reaction, there are at least two silane coupling agents; the silane coupling agent is selected from: vinyl trimethoxysilane, vinyl triethoxysilane, tris-isocyanate propyl trimethoxysilane, tris-isocyanate propyl triethoxysilane, phenyl triethoxysilane, phenyl trimethoxysilane, allyl trimethoxysilane, allyl triethoxysilane, methacryloxypropyl trimethoxysilane, methacryloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl triethoxysilane, etc., preferably vinyl trimethoxysilane, methacryloxypropyl trimethoxysilane, allyl trimethoxysilane and phenyl trimethoxysilane. 3. The method for preparing a silicone-modified hydroxy acrylic resin according to claim 1, characterized in that, in the hydrolysis condensation reaction, the catalyst is selected from any one of concentrated hydrochloric acid, concentrated sulfuric acid, sodium hydroxide, potassium hydroxide and p-toluenesulfonic acid. 4. The method for preparing a silicone-modified hydroxy acrylic resin according to claim 3, characterized in that, in the hydrolysis condensation reaction, when the catalyst is sodium hydroxide or potassium hydroxide, it also includes: adding an acidic neutralizing agent to the reaction solution after the hydrolysis condensation reaction to carry out a neutralization reaction. 5. The method for preparing the organosilicon-modified hydroxy acrylic resin according to claim 1, characterized in that, in the free radical polymerization reaction, the mass ratio of the mixed material to the organosilicon alcohol is 1:(0.1-0.3). 6. The method for preparing the organosilicon-modified hydroxy acrylic resin according to claim 5, characterized in that in the mixed material, the mass ratio of the silane coupling agent to the acrylate, acrylic acid and styrene is 1:(10-13):(0.5-2):(0.3-6). 7 . The method for preparing a silicone-modified hydroxy acrylic resin according to claim 1 , wherein in the free radical polymerization reaction, the silane coupling agent with a double bond is methacryloxypropyl tris(trimethylsiloxy)silane. 8. The method for preparing a silicone-modified hydroxy acrylic resin according to claim 1, characterized in that, in the free radical polymerization reaction, the initiator is selected from any one of dibenzoyl peroxide, tert-amyl peroxide 2-ethylhexyl carbonate, azobisisobutyronitrile, azobisisoheptylnitrile and tert-butyl perbenzoate. 9. The method for preparing a silicone-modified hydroxy acrylic resin according to claim 1, wherein in the free radical polymerization reaction, the amount of the initiator added is 1-4%. 10. An organosilicon-modified hydroxy acrylic resin prepared according to the preparation method according to any one of claims 1 to 9.