Active silicone oil for hydroxyl acrylic resin modification, preparation method of active silicone oil and organic silicon modified hydroxyl acrylic resin

Abstract

The invention provides active silicone oil for hydroxyl acrylic resin modification, a preparation method of the active silicone oil and organic silicon modified hydroxyl acrylic resin, and relates to the technical field of polymer coating compositions. The preparation method of the hydroxyl acrylic resin modified active silicone oil comprises the following steps: firstly, carrying out addition reaction on an allyl monomer and hydrogen-containing silicone oil under the condition of platinum catalysis to obtain a hydroxyl-containing organic silicon prepolymer; then carrying out chain extension on the organic silicon prepolymer and isocyanate under a catalytic condition, and then carrying out end capping by using a polymerizable hydroxyl monomer, so as to obtain the active silicone oil for modifying the hydroxyl acrylic resin. Through verification, the active silicone oil is used as a raw material and is mixed with acrylic ester / metacrylic ester for copolymerization to obtain organic silicon modified acrylic resin, and the organic silicon modified acrylic resin has better corrosion resistance, heat resistance, weather resistance, smoothness and scratch resistance and is applied to a transparent coating of vehicle paint; the aging resistance, the water resistance and the solvent resistance of the transparent coating can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of polymer coating compositions, in particular to an active silicone oil for modifying hydroxy acrylic resin and a preparation method thereof, and an organosilicon-modified hydroxy acrylic resin. Background Art

[0002] The combination of basecoat and topcoat as a car paint has become quite common and popular. This car paint combination system has excellent appearance, such as high gloss, good clarity, etc. In practical applications, a good topcoat not only has requirements on transparency, but also must have technical effects of water resistance, radiation resistance, and scratch resistance. Usually these requirements can be solved by increasing the crosslinking density of the resin. However, increasing crosslinking will cause the resin to become brittle and prone to cracking after painting.

[0003] Therefore, it is necessary and urgent to research and develop a silicone-modified hydroxyl acrylic resin with the advantages of scratch resistance, corrosion resistance and weather resistance for application in the clear coating of car paint.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The first object of the present invention is to provide a method for preparing an active silicone oil for modification of hydroxy acrylic resin, wherein the active silicone oil for modification of hydroxy acrylic resin obtained by the preparation method has been verified to have good corrosion resistance, heat resistance, weather resistance and smooth scratch resistance, and is applied to the clear coating of car paint to effectively improve the aging resistance, water resistance and solvent resistance of the clear coating.

[0006] The second object of the present invention is to provide a silicone-modified hydroxy acrylic resin.

[0007] The third object of the present invention is to provide an application of a silicone-modified hydroxy acrylic resin in the preparation of a topcoat in a vehicle paint combination.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0009] The present invention provides a method for preparing an active silicone oil modified with a hydroxy acrylic resin, the method comprising:

[0010] (A) subjecting an allyl monomer to an addition reaction with a hydrogen-containing silicone oil under a platinum-catalyzed condition to obtain a hydroxyl-containing organosilicon prepolymer;

[0011] (B) The organosilicon prepolymer is chain extended with isocyanate under catalytic conditions, and then end-capped with a polymerizable hydroxyl monomer to obtain an active silicone oil for modification of hydroxyl acrylic resin.

[0012] Furthermore, the allyl monomer is a bifunctional or multifunctional allyl monomer containing a hydroxyl group;

[0013] Preferably, the allyl monomer includes at least one of pentaerythritol allyl ether, polyethylene glycol allyl ether, polypropylene glycol allyl ether, trimethylolpropane diallyl ether, and allyl glycidyl ether;

[0014] Preferably, the hydrogen-containing silicone oil includes at least one of trimethylsilane, triphenylsilane, bis(trimethylsiloxy)methylsilane, and 1133-tetramethyldisiloxane.

[0015] Further, the isocyanate is isophorone diisocyanate;

[0016] Preferably, the polymerizable hydroxyl monomer includes at least one of hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate (HEA), hydroxypropyl acrylate (HPA), hydroxypropyl methacrylate (HPMA), and hydroxyethyl acrylate.

[0017] Furthermore, the temperature of the addition reaction in step (A) is 75-80° C., and the time of the addition reaction is reflux reaction for 30-60 minutes, followed by standing for 12-15 hours.

[0018] Preferably, the addition reaction is carried out under a nitrogen atmosphere.

[0019] Furthermore, in the step (B), the molar ratio of the organosilicon prepolymer, isocyanate and polymerizable hydroxyl monomer is (0.9-1.1):(1-1.2):(0.9-1.1).

[0020] Further, the chain extension in step (B) comprises:

[0021] Stir the silicone prepolymer, isocyanate and catalyst at 40-60°C for 2 hours, then heat to 60-70°C for 2 hours;

[0022] Preferably, the catalyst is an organotin catalyst.

[0023] Furthermore, the end-capping step (B) comprises: adding a polymerizable hydroxyl monomer into the reaction system, and stirring the reaction at a temperature of 65 to 70° C. for 1 to 3 hours.

[0024] The present invention provides an active silicone oil for modifying hydroxy acrylic resin, wherein the active silicone oil is prepared by the active silicone oil preparation method.

[0025] The present invention provides an organosilicon-modified hydroxy acrylic resin, which comprises, by mass percentage,:

[0026] Styrene 20-25%, active silicone oil 2-10%, butyl acrylate 15-32%, butyl methacrylate 10-15%, hydroxyl-containing monomer 18-30%, acrylic acid 0.5-1.5%, initiator 0.5-10%;

[0027] The sum of the mass percentages of the raw materials in the organosilicon-modified hydroxy acrylic resin is 100%.

[0028] The present invention provides an application of the organosilicon-modified hydroxy acrylic resin in preparing a topcoat in a vehicle paint combination.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a method for preparing an active silicone oil for modifying a hydroxy acrylic resin. The method firstly performs an addition reaction between an allyl monomer and a hydrogenated silicone oil under platinum catalysis to obtain a hydroxyl-containing organosilicon prepolymer; then, the organosilicon prepolymer is chain extended with isocyanate under catalytic conditions, and then a polymerizable hydroxyl monomer is used for end-capping to obtain an active silicone oil for modifying a hydroxy acrylic resin. It has been verified that the organosilicon-modified acrylic resin obtained by using the active silicone oil of the present application as a raw material and mixing it with acrylate / methacrylate and then copolymerizing it has better corrosion resistance, heat resistance, weather resistance, and smooth and scratch resistance. When applied to the clear coating of car paint, it can effectively improve the aging resistance, water resistance, and solvent resistance of the clear coating.

[0031] The organosilicon-modified hydroxy acrylic resin provided by the present invention is mainly prepared by copolymerization of styrene, active silicone oil, butyl acrylate, butyl methacrylate, hydroxyl-containing monomer, AA and initiator mixed in a specific ratio. The organosilicon-modified hydroxy acrylic resin has good corrosion resistance, heat resistance, weather resistance and smooth and scratch resistance.

[0032] The organosilicon-modified hydroxy acrylic resin provided by the present invention can be widely used in the preparation of topcoat in a car paint combination. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] According to one aspect of the present invention, a method for preparing an active silicone oil modified with a hydroxy acrylic resin comprises:

[0035] (A) subjecting an allyl monomer to an addition reaction with a hydrogen-containing silicone oil under a platinum-catalyzed condition to obtain a hydroxyl-containing organosilicon prepolymer;

[0036] (B) The organosilicon prepolymer is chain extended with isocyanate under catalytic conditions, and then end-capped with a polymerizable hydroxyl monomer to obtain an active silicone oil for modification of hydroxyl acrylic resin.

[0037] The present invention provides a method for preparing an active silicone oil for modifying a hydroxy acrylic resin. The method firstly performs an addition reaction between an allyl monomer and a hydrogenated silicone oil under platinum catalysis to obtain a hydroxyl-containing organosilicon prepolymer; then, the organosilicon prepolymer and isocyanate are chain extended under catalytic conditions, and then a polymerizable hydroxyl monomer is used for end-capping to obtain an active silicone oil for modifying a hydroxy acrylic resin. It has been verified that the organosilicon-modified acrylic resin obtained by using the active silicone oil of the present application as a raw material and mixing it with acrylate / methacrylate and then copolymerizing it has better corrosion resistance, heat resistance, weather resistance, and smooth and scratch resistance. When applied to the clear coating of car paint, it can effectively improve the aging resistance, water resistance, and solvent resistance of the clear coating.

[0038] In a preferred embodiment of the present invention, the allyl monomer is a bifunctional or multifunctional allyl monomer containing a hydroxyl group;

[0039] In the above preferred embodiment, the allyl monomer includes at least one of pentaerythritol allyl ether, polyethylene glycol allyl ether, polypropylene glycol allyl ether, trimethylolpropane diallyl ether, and allyl glycidyl ether;

[0040] In the above preferred embodiment, the hydrogen-containing silicone oil includes at least one of trimethylsilane, triphenylsilane, bis(trimethylsiloxy)methylsilane, and 1133-tetramethyldisiloxane.

[0041] In a preferred embodiment of the present invention, the isocyanate is isophorone diisocyanate;

[0042] In the above preferred embodiment, the polymerizable hydroxyl monomer includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and hydroxyethyl acrylate.

[0043] In a preferred embodiment of the present invention, the temperature of the addition reaction in step (A) is 75-80° C., and the time of the addition reaction is reflux reaction for 30-60 minutes, followed by standing for 12-15 hours.

[0044] Preferably, the addition reaction is carried out under a nitrogen atmosphere.

[0045] In a preferred embodiment of the present invention, the molar ratio of the organosilicon prepolymer, isocyanate and polymerizable hydroxyl monomer in step (B) is (0.9-1.1):(1-1.2):(0.9-1.1).

[0046] In a preferred embodiment of the present invention, the chain extension in step (B) comprises:

[0047] The silicone prepolymer, isocyanate and catalyst were stirred and reacted at 50°C for 2 hours, and then heated to 65°C and stirred and reacted for 2 hours;

[0048] Preferably, the catalyst is an organotin catalyst.

[0049] In a preferred embodiment of the present invention, the end-capping step (B) comprises: adding a polymerizable hydroxyl monomer into the reaction system and stirring the reaction at a temperature of 65-70° C. for 2 hours.

[0050] According to one aspect of the present invention, an active silicone oil for modifying hydroxy acrylic resin is prepared by the above-mentioned active silicone oil preparation method.

[0051] The active silicone oil for modifying hydroxy acrylic resin provided in the present application is mainly prepared by the above-mentioned active silicone oil preparation method.

[0052] According to one aspect of the present invention, a silicone-modified hydroxy acrylic resin comprises, by mass percentage,:

[0053] Styrene 20-25%, the above active silicone oil 2-10%, butyl acrylate 15-32%, butyl methacrylate 10-15%, hydroxyl-containing monomer 18-30%, acrylic acid (AA) 0.5-1.5%, initiator 0.5-10%;

[0054] The sum of the mass percentages of the raw materials in the organosilicon-modified hydroxy acrylic resin is 100%.

[0055] The organosilicon-modified hydroxy acrylic resin provided by the present invention is mainly prepared by copolymerizing styrene, active silicone oil, butyl acrylate, butyl methacrylate, hydroxyl-containing monomer, AA, and initiator in a specific ratio. The present application can effectively improve the corrosion resistance, heat resistance, weather resistance, and smoothness and scratch resistance of the hydroxy acrylic resin by copolymerizing the active silicone oil with acrylate and methacrylate.

[0056] According to one aspect of the present invention, the above-mentioned organosilicon-modified hydroxy acrylic resin is used in preparing a topcoat in a car paint combination.

[0057] The organosilicon-modified hydroxy acrylic resin provided by the present invention can be widely used in the preparation of topcoat in a car paint combination.

[0058] It should be noted that the above-mentioned vehicle paint combination is a combination of base paint and topcoat.

[0059] The technical solution of the present invention will be further described below in conjunction with embodiments.

[0060] Example 1

[0061] A method for preparing an active silicone oil modified with a hydroxy acrylic resin, the method comprising:

[0062] (A) 930 g of trimethylolpropane diallyl ether, 1.2 ml of platinum catalyst, and 198.4 g of allyl glycidyl ether were added to a reaction bottle filled with nitrogen, and then 700 g of 1133-tetramethyldisiloxane was slowly added dropwise to the bottle for 3-5 hours. The temperature of the reactants was kept at 50° C. The disappearance of Si-H bonds was monitored by infrared spectroscopy to obtain an organosilicon prepolymer;

[0063] (B) Put the organosilicon prepolymer, isophorone diisocyanate (IPDI), and organotin catalyst (T-12 catalyst) into a stirred flask, control the temperature at 50°C, and stir for 2 hours. Then raise the temperature to 65°C, and stir and react for another 2 hours.

[0064] Then, the monomer hydroxyethyl acrylate was slowly added to the above reaction system through a drop pump, the reaction system was controlled not to exceed 70°C, and the reaction was continued for 2 hours to obtain active silicone oil. The active silicone oil was transferred to a sealed metal barrel while hot and cooled for later use.

[0065] The molar ratio of silicone prepolymer / IPDI / hydroxyethyl acrylate is 1:1:1.05. The catalyst is 0.05% of the raw materials (silicone prepolymer, IPDA, hydroxyethyl acrylate).

[0066] Example 2

[0067] A method for preparing an active silicone oil modified with a hydroxy acrylic resin, the method comprising:

[0068] (A) Same as Example 1;

[0069] (B) Add the organosilicon prepolymer, isophorone diisocyanate (IPDI) and organotin catalyst into a stirring flask, control the temperature at 50°C, and stir for 2 hours. Then raise the temperature to 65°C and stir for another 2 hours.

[0070] Then, the monomer hydroxyethyl acrylate was slowly added to the above reaction system through a drop pump, the reaction system was controlled not to exceed 70°C, and the reaction was continued for 2 hours to obtain active silicone oil. The active silicone oil was transferred to a sealed metal barrel while hot and cooled for later use.

[0071] The molar ratio of silicone prepolymer / IPDI / hydroxyethyl acrylate is 0.95:1:1.1. The catalyst is 0.05% of the raw materials (organic silicone prepolymer, IPDA, hydroxyethyl acrylate).

[0072] Example 3

[0073] A method for preparing an active silicone oil modified with a hydroxy acrylic resin, the method comprising:

[0074] (A) Same as Example 1;

[0075] (B) Add the organosilicon prepolymer, isophorone diisocyanate (IPDI) and organotin catalyst into a stirring flask, control the temperature at 50°C, and stir for 2 hours. Then raise the temperature to 65°C and stir for another 2 hours.

[0076] Then, the monomer hydroxyethyl acrylate was slowly added to the above reaction system through a drop pump, the reaction system was controlled not to exceed 70°C, and the reaction was continued for 2 hours to obtain active silicone oil. The active silicone oil was transferred to a sealed metal barrel while hot and cooled for later use.

[0077] The molar ratio of silicone prepolymer / IPDI / hydroxyethyl acrylate is 1.05:1:0.95. The catalyst is 0.05% of the raw materials (organic silicone prepolymer, IPDA, hydroxyethyl acrylate).

[0078] Embodiments 4 to 6

[0079] A silicone-modified hydroxy acrylic resin, which comprises, by mass percentage:

[0080]

[0081]

[0082] Note: The mass ratio of HEMA to HEA in the hydroxyl-containing monomers in the above table is 1:3.

[0083] The synthesis method of the organosilicon-modified hydroxy acrylic resin in the above-mentioned Examples 4 to 6 is as follows:

[0084] Add a portion of the reaction solvent to a 500ml four-necked reaction flask equipped with a mechanical stirrer. After the solvent refluxes, add the monomer mixed solution containing the initiator prepared according to the formula shown in the table to the reaction flask at a constant speed using a constant pressure dropping funnel. After the monomer addition is completed; add an initiator with a monomer content of 0.2% under reflux and keep warm for 2.5 hours. After the insulation is completed, vacuum extract a certain amount of reaction solvent and add an appropriate amount of solvent to dilute the resin.

[0085] Example 7

[0086] This embodiment is the same as Embodiment 4 except that the "active silicone oil prepared in Embodiment 1" in the organosilicon-modified hydroxy acrylic resin is replaced by "active silicone oil prepared in Embodiment 2".

[0087] Example 8

[0088] This example is the same as Example 4 except that the "active silicone oil prepared in Example 1" in the organosilicon-modified hydroxy acrylic resin is replaced by "active silicone oil prepared in Example 3". Comparative Example 1 (Conventional Hydroxy Acrylic Resin)

[0089] A hydroxy acrylic resin, which comprises, by mass percentage:

[0090]

[0091]

[0092] Note: The mass ratio of HEMA to HEA in the hydroxyl-containing monomers in the above table is 1:3.

[0093] The preparation method of the hydroxy acrylic resin comprises:

[0094] Add a portion of the reaction solvent to a 500ml four-necked reaction flask equipped with a mechanical stirrer. After the solvent refluxes, add the monomer mixed solution containing the initiator prepared according to the formula shown in the table to the reaction flask at a constant speed using a constant pressure dropping funnel. After the monomer addition is completed; add an initiator with a monomer content of 0.2% under reflux and keep warm for 2.5 hours. After the insulation is completed, vacuum extract a certain amount of reaction solvent and add an appropriate amount of solvent to dilute the resin.

[0095] The main difference between this comparative example and Example 4 is that it does not contain the "active silicone oil prepared in Example 1".

[0096] Test Example 1

[0097] In order to show that the silicone-modified hydroxy acrylic resin of the present application has better corrosion resistance, heat resistance, weather resistance and smooth scratch resistance after being used as a raw material to prepare a coating resin, its application in a car paint clear coating can effectively improve the aging resistance, water resistance and solvent resistance of the clear coating. The hydroxy acrylic resins prepared in Examples 4 to 8 and Comparative Example 1 are now used in coating preparation, and the performance of the coating film is evaluated.

[0098] The raw material composition of the coating is as follows:

[0099]

[0100]

[0101] The hydroxy acrylic resin in the test group 1 is the organosilicon-modified hydroxy acrylic resin prepared in Example 4;

[0102] The hydroxylated acrylic resin in the test group 2 is the organosilicon-modified hydroxylated acrylic resin prepared in Example 5;

[0103] The hydroxy acrylic resin in the test group 3 is the organosilicon-modified hydroxy acrylic resin prepared in Example 6;

[0104] The hydroxy acrylic resin in the test group 4 is the organosilicon-modified hydroxy acrylic resin prepared in Example 7;

[0105] The hydroxy acrylic resin in the test group 5 is the organosilicon-modified hydroxy acrylic resin prepared in Example 8;

[0106] The hydroxylated acrylic resin in the test group 6 is the hydroxylated acrylic resin prepared in the comparative example 1.

[0107] The evaluation results of the coating film are as follows:

[0108]

[0109]

[0110] It can be seen from the above table that the coating formed by the silicone-modified hydroxy acrylic resin has obvious improvements in aging resistance, water resistance and solvent resistance.

[0111] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an active silicone oil modified with a hydroxy acrylic resin, characterized in that: The preparation method comprises: (A) subjecting an allyl monomer to an addition reaction with a hydrogen-containing silicone oil under a platinum-catalyzed condition to obtain a hydroxyl-containing organosilicon prepolymer; (B) The organosilicon prepolymer is chain extended with isocyanate under catalytic conditions, and then end-capped with a polymerizable hydroxyl monomer to obtain an active silicone oil for modification of hydroxyl acrylic resin.

2. The method for preparing active silicone oil according to claim 1, characterized in that: The allyl monomer is a bifunctional or multifunctional allyl monomer containing a hydroxyl group; Preferably, the allyl monomer includes at least one of pentaerythritol allyl ether, polyethylene glycol allyl ether, polypropylene glycol allyl ether, trimethylolpropane diallyl ether, and allyl glycidyl ether; Preferably, the hydrogen-containing silicone oil includes at least one of trimethylsilane, triphenylsilane, bis(trimethylsiloxy)methylsilane, and 1133-tetramethyldisiloxane.

3. The method for preparing active silicone oil according to claim 1, characterized in that: The isocyanate is isophorone diisocyanate; Preferably, the polymerizable hydroxyl monomer includes at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, and hydroxyethyl acrylate.

4. The method for preparing active silicone oil according to claim 1, characterized in that: The temperature of the addition reaction in step (A) is 75-80° C., and the time of the addition reaction is reflux reaction for 30-60 minutes, followed by standing for 12-15 hours; Preferably, the addition reaction is carried out under a nitrogen atmosphere.

5. The method for preparing active silicone oil according to claim 1, characterized in that: In the step (B), the molar ratio of the organosilicon prepolymer, isocyanate and polymerizable hydroxyl monomer is (0.9-1.1): (1-1.2): (0.9-1.1).

6. The method for preparing active silicone oil according to claim 1, characterized in that: The chain extension step (B) comprises: Stir the silicone prepolymer, isocyanate and catalyst at 40-60°C for 2 hours, then heat to 60-70°C for 2 hours; Preferably, the catalyst is an organotin catalyst.

7. The method for preparing active silicone oil according to claim 1, characterized in that: The end-capping step (B) comprises: adding a polymerizable hydroxyl monomer into a reaction system, and reacting the mixture by stirring at a temperature of 65 to 70° C. for 1 to 3 hours.

8. An active silicone oil for modifying hydroxy acrylic resin, characterized in that: The active silicone oil is prepared by the method for preparing the active silicone oil according to any one of claims 1 to 7.

9. A silicone-modified hydroxy acrylic resin, characterized in that: Measured by mass percentage, the organosilicon-modified hydroxy acrylic resin includes: 20-25% styrene, 2-10% active silicone oil prepared according to any one of claims 1 to 7, 15-32% butyl acrylate, 10-15% butyl methacrylate, 18-30% hydroxyl-containing monomer, 0.5-1.5% acrylic acid, and 0.5-10% initiator; The sum of the mass percentages of the raw materials in the organosilicon-modified hydroxy acrylic resin is 100%.

10. Use of the organosilicon-modified hydroxy acrylic resin according to claim 9 in preparing a topcoat in a vehicle paint combination.

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