CN106916503B

CN106916503B - Single-component varnish composition, preparation method and application thereof

Info

Publication number: CN106916503B
Application number: CN201710226719.0A
Authority: CN
Inventors: 张萌; 夏天渊; 果建军; 梅鹏; 张景斌
Original assignee: Libang Coatings (china) Co Ltd; NIPPON PAINT (GUANGZHOU) CO Ltd; Langfang Nippon Paint Co Ltd
Current assignee: Libang Coatings (china) Co Ltd; NIPPON PAINT (GUANGZHOU) CO Ltd; Langfang Nippon Paint Co Ltd
Priority date: 2017-04-09
Filing date: 2017-04-09
Publication date: 2020-03-17
Anticipated expiration: 2037-04-09
Also published as: CN106916503A

Abstract

The invention discloses a one-component varnish composition, comprising at least one polymer with a hyperbranched or dendritic structure; at least one hydroxy acrylic resin or hydroxy methacrylic resin; at least one silicone-modified acrylic resin; at least one crosslinking curing agent; at least one acid catalyst; at least one rheology control agent; at least one auxiliary agent, and at least one solvent; the one-component varnish composition is a high scratch-resistant and high weather-resistant one-component varnish composition. The high-scratch-resistant and high-weather-resistant single-component varnish composition provided by the invention can effectively improve the smoothness of the coating surface of the varnish composition, so that the friction resistance of the coating is improved; in addition, the introduction of the silicone modified acrylic resin can further improve the weather resistance of the varnish composition coating film.

Description

Single-component varnish composition, preparation method and application thereof

Technical Field

The invention belongs to the technical field of paint preparation, relates to a varnish composition, a preparation method and application thereof, and particularly relates to a high-scratch-resistant and high-weather-resistant single-component varnish composition and a preparation method thereof, and an application method of the high-scratch-resistant and high-weather-resistant single-component varnish composition which is coated on a substrate according to different construction processes to form a cured coating or prepare a multi-coating finishing system.

Background

At present, automobiles are the most common daily tool for riding instead of walk for people, and the automobiles gradually go deep into thousands of households. With the increasing demand of automobiles, the demands for appearance and performance of automobiles are also increasing. The automobile body can be endowed with excellent appearance by spraying automobile paint, and various performances of the automobile body can be improved. In daily life, automobiles are often exposed to the sun by the owner of the automobile or are washed by sending the automobile to a washing shop, which requires excellent weather resistance and abrasion resistance of the coating layer applied to the surface of the automobile body, and these properties are mainly determined by the outermost protective decorative coating layer of the automobile coating film. The varnish which is coated on the top coat to form the outermost protective decorative coating is commonly called as finishing varnish, and is characterized by high lightness, high gloss, good adhesion, high hardness and good fullness, and simultaneously has excellent water resistance, gasoline resistance, chemical resistance, wear resistance, weather resistance and other properties, so the varnish is widely applied to the surface coating of high-grade vehicles such as medium and high-grade automobiles, luxury passenger cars, station wagons and the like.

The organic silicon is a polymer which takes repeated Si-O-Si bonds as a main chain and is directly connected with organic groups on silicon atoms, and is not easy to be decomposed by ultraviolet light and ozone, so that the organic silicon has better irradiation resistance and weather resistance than other high polymer materials; on the other hand, the main chain of the organic silicon is very soft and flexible, and the intermolecular action force is much weaker than that of a hydrocarbon compound, so that the organic silicon has the characteristics of weak surface tension, small surface energy, strong film forming capability and the like, and therefore, after the organic silicon modified acrylic resin is added into a paint film, the paint film can be endowed with good scratch resistance and stain resistance, and meanwhile, the paint film has good smooth hand feeling.

World patent WO0198393 discloses a process for the preparation of a two-component varnish composition. The varnish composition consists of a base material containing a polyol polymer and a curing agent containing a portion of isocyanate groups modified with an alkoxysilane, and is useful as a paint/varnish system for automotive refinish and refinish finishes in automotive coatings, but the patent does not describe the varnish composition as optimally weatherable and abrasion resistant.

European patent EP994117 discloses a composition which can be cured by moisture. The composition consists of a base material containing a polyol polymer and a polyisocyanate curing agent containing a portion of the isocyanate groups modified with a monoalkoxysilylamine. The coating prepared by using the composition has special film hardness, but the application of the composition in the field of automobile finishing has limitations aiming at weather resistance and friction resistance.

U.S. patent US20060217472 discloses a coating composition containing a hydroxyacrylic acid, a low molecular weight polyol component, a polyisocyanate, and an aminoalkoxysilane component. The coating composition can be used as an automotive varnish in a paint/varnish system to impart abrasion resistance to a varnish coating, but the coating composition has poor storage stability, particularly poor weather resistance stability against UV rays in a dry-wet alternating environment.

World patent WO2006042585 discloses a varnish composition suitable for automotive finishes. The main base material component of the varnish composition contains silane modified polyisocyanate, wherein more than 90 percent of isocyanate groups in the polyisocyanate are reacted with the bis-alkoxy silicon-based amine. The varnish composition has excellent friction resistance and high chemical resistance and weather resistance, but the varnish composition still needs to further improve and promote the weather resistance stability, especially the weather resistance stability against UV rays under a dry-wet alternating environment.

European patent EP1273640 discloses a two-component varnish composition suitable for automobile finishing. The composition is composed of a polyol polymer component and a curing agent component consisting of an aliphatic and/or alicyclic polyisocyanate, wherein: 0.1 to 95 percent of isocyanate groups in the curing agent component react with the bis-alkoxy silicon-based amine. However, when the varnish composition is used for automobile coating, the coating film after being fully cured has good abrasion resistance under the influence of the external environment. However, the clearcoat compositions have a very strong tendency to postcrosslink, which has a negative effect on the weathering stability.

US8569438 discloses a varnish composition having high abrasion resistance and weathering stability. The varnish composition consists of a hydroxyl-containing component A, an isocyanate-containing component B and a phosphorus-containing catalyst component which can be used for catalyzing silane groups to carry out crosslinking.

By analyzing the above documents, it is mentioned that silicone is used for improving the abrasion resistance of a coating film of a varnish composition, and the silicone component for improving the coating film performance is mainly a small-molecular alkyl silane containing a reactive group. By means of reactive groups contained in the silane, for example: amino and hydroxyl react with isocyanate to obtain partially or completely blocked silane modified isocyanate, and the isocyanate is used as a curing agent component to prepare two-component varnish or single-component varnish; the Si-O-R group in the silane is utilized to carry out hydrolytic crosslinking to form a poly-organic silicon structure containing Si-O-Si repeating units, thereby improving the friction resistance of a paint film. However, the use of silanes, while increasing the abrasion resistance, also has associated negative effects on the paint film. The Si-O-R group can also be hydrolyzed to react with hydroxyl groups in the resin, which is advantageous for increasing the crosslinking density and improving the abrasion resistance, but the newly formed Si-O-C group is easily hydrolyzed and thus has relatively poor weather resistance stability under wet heat conditions.

In view of the above, there is a need for a high scratch-resistant and high weathering one-component varnish composition having good abrasion resistance and weathering stability.

Disclosure of Invention

In view of the above-mentioned disadvantages of the prior art, it is an object of the present invention to provide a highly scratch-resistant and highly weather-resistant one-component varnish composition having good abrasion resistance and weather resistance stability.

The invention also aims to provide a preparation method of the high-scratch-resistant and high-weather-resistant single-component varnish composition, and particularly relates to a preparation method of the high-scratch-resistant and high-weather-resistant single-component varnish composition by using a specific preparation method to prepare a hyperbranched or dendritic polymer, hydroxy acrylic acid, a silicone modified acrylic resin, a cross-linking agent, a rheology control agent and other components.

It is a further object of the present invention to provide a use of the one-component varnish composition with high scratch resistance and high weatherability, in particular an application method of applying the one-component varnish composition with high scratch resistance and high weatherability to a substrate according to different application processes to form a cured varnish coating and to prepare a multi-coat finishing system.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

one aspect of the present invention provides a high scratch-resistant and high weather-resistant one-component varnish composition comprising:

at least one polymer having a hyperbranched or dendritic structure;

at least one hydroxy acrylic resin or hydroxy methacrylic resin;

at least one silicone-modified acrylic resin;

at least one crosslinking curing agent;

at least one acid catalyst;

at least one rheology control agent;

at least one kind of auxiliary agent is used,

and

at least one solvent.

Preferably, one aspect of the present invention provides a high scratch-resistant and high weather-resistant one-component varnish composition comprising the following components in parts by weight:

preferably, the polymer with hyperbranched or dendritic structure is a high molecular polyester with hyperbranched or dendritic structure, each high molecular polymer chain contains 8-80 hydroxyl groups on average, the hydroxyl value is between 150-600 mgKOH/g, and the glass transition temperature (Tg) is between-25 ℃ and +30 ℃. For the purposes of the present invention, the polymers having a hyperbranched or dendritic structure may be chosen from those of Singapore Tech technology Ltd and of Nippon coatings China Ltd

BB600 resin,

BB900 resin and

a BB400 resin; wherein the content of the first and second substances,

the BB600 resin has a solid content of 61-63%, an acid value of 5-6 mgKOH/g, and a solid hydroxyl value of 209 mgKOH/g;

the solid content of the BB900 resin is 54-58%, the acid value is 2-8 mgKOH/g, and the solid hydroxyl value is 279 mgKOH/g;

the BB400 resin has a solid content of 65 to 68%, an acid value of 3 to 6mgKOH/g, and a solid hydroxyl value of 280 mgKOH/g.

Hydroxyl in the polymer with the hyperbranched or dendritic structure can be selectively modified and substituted by epoxy groups and blocked aliphatic isocyanate groups, so that epoxy modified hyperbranched polyester resin and blocked isocyanate modified hyperbranched polyester resin are obtained; and the number of the modified and substituted functional groups, namely the number of the substituted hydroxyl groups, accounts for 1 to 50 percent of the number of the hydroxyl groups in the original hyperbranched or dendritic polymer.

The epoxy modified hyperbranched polyester resin is prepared by taking hyperbranched hydroxyl polyester, anhydride and epoxy resin as raw materials and has the following structural formula:

wherein m and n are positive integers, and m + n ≦ 80; wherein the content of the first and second substances,

as backbone for hyperbranched hydroxyl polyesters, the backbone structure has been described in the prior art literature [ see in particular: determination of Structure, solution and Overall Properties of aliphatic hyperbranched polyesters based on 2, 2-Dimethylolpropionic acid, advanced science of macromolecules, stage 36, 2011, P_53～88(ii) a And hyperbranched copolymer micelles as adriamycin carriers in breast cancer cells, journal of Polymer science: polymer chemistry, 50 th stage 2012, P_280～288. (Aliphatic Hyperbranched polyesters based on 2, 2-bis (methyl)) pro pionic acid-Determination of structure, solution and bulk properties ". Progress in Polymer Science,2011, 36: 53-88." Hyperbranched copolymers from derivatives of doxobicin in branched cells "Journal of Polymer Science Part A: Polymer Chemistry,2012, 50: 280-288 ], which is not described herein again; r₁The alkyl group remained after removing the anhydride group in the anhydride molecule, wherein the anhydride is hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, phthalic anhydride, maleic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, dodecenylAt least one of succinic anhydride and trimellitic anhydride; r₂The epoxy resin is an alkyl group remained after epoxy groups are removed from epoxy resin molecules, wherein the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1, 2-propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1, 4-butylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, phthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester and tetrahydrophthalic acid diglycidyl ester.

The blocked isocyanate modified hyperbranched polyester resin is prepared by taking hyperbranched hydroxyl polyester, isocyanate and a blocking agent as raw materials, and has the following structural formula:

wherein x and y are positive integers, and 2 ≦ x + y ≦ total number of functional groups of the hyperbranched hydroxyl polyester;

being a backbone of hyperbranched hydroxy polyester, R₃The isocyanate is an alkyl group remained after removing isocyanate groups in isocyanate molecules, wherein the isocyanate is at least one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane isocyanate, trimethyl hexamethylene diisocyanate and hydrogenated toluene diisocyanate; r₄Is an alkyl group remained after removing active hydrogen in a sealant molecule, wherein: the sealant is methanol, ethanol, propanol, butanol, hexanol, octanol, benzyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycolAt least one of glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether, methyl ethyl ketone oxime, acetone oxime, cyclohexanone oxime, diisopropylamine, 3, 5-dimethylpyrazole, N-tert-butylbenzylamine, caprolactam, dimethyl malonate and diethyl malonate.

The amount of the hyperbranched or dendritic polymer is preferably 3 to 10 parts by weight, based on 1 to 20 parts by weight. When the addition amount of the polymer with the hyperbranched or dendritic structure is less than 1 part, the viscosity reduction, curing response and film crosslinking density of the system and the reduction of the film shrinkage rate cannot reach the level under an ideal state; when the amount of the polymer having a hyperbranched or dendritic structure is more than 20 parts, the residual unreacted functional groups in the system impair the dry film toughness and chemical resistance of the coating.

The hydroxyl value of the hydroxyl acrylic resin or the hydroxyl methacrylic resin is between 110 and 250mg KOH/g, the glass transition temperature (Tg) is between-10 ℃ and +35 ℃, the number average molecular weight is between 2000 and 4000, and the solid content is more than or equal to 80 percent. In the present invention, the hydroxy acrylic resin or hydroxy methacrylic resin is obtained by radical polymerization using a derivative of an acrylic ester and/or methacrylic ester monomer, a derivative of a hydroxyl group-containing acrylic ester and/or methacrylic ester monomer, a derivative of a carboxyl group-containing acrylic acid and/or methacrylic acid, and a monomer having a carbon-carbon double bond and capable of undergoing a copolymerization reaction as raw materials under the action of an initiator.

The structure of the organic silicon modified acrylic resin is shown as a general formula I:

wherein:

in formula I:

R₁selected from aliphatic, alicyclic and aromatic alkyl, alkoxy, acyloxy, hydroxyalkyl and hydroxyalkylene containing 1-20 carbon atoms;

R₂、R₃、R₄、R₅each independently selected from hydrogen atomsAliphatic, alicyclic and aromatic alkyl, hydroxyalkyl and hydroxyalkylene containing 1 to 20 carbon atoms;

R₆is selected from one of the formulas II:

CH₂CH₂CH₂OH CH₂CH₂CH₂CH2OH CH₂CH₂CH₂CH₂CH₂OH

CH₂CH₂CH₂CH₂CH₂CH₂OH CH₂CH₂CH₂OCH₂CH(OH)CH₂OCH₃

(II)；

R₇is selected from one of the formulas III:

CH₃CH₂CH₂CH₂CH₃CH(CH₃)CH₂(CH₃)₃C (CH₃)₃SiO

(III)；

m>0，n>0，o>0，p>0，q>0，x>0，y>0。

the alkyl group referred to in formula I includes a straight chain or branched chain alkyl group. Aliphatic, alicyclic and aromatic alkyl, alkoxy, acyloxy, hydroxyalkyl and hydroxyalkylene groups of the general formula I are exemplified below: alkyl is ethyl belonging to aliphatic alkyl; alkyl is phenyl belonging to the aromatic group; the alkyl group is a cyclohexane group belonging to alicyclic alkyl groups. Similarly, alkoxy is ethoxy belonging to aliphatic alkoxy; alkoxy is phenoxy belonging to the group of aromatic alkoxy; alkoxy is cyclohexyloxy belongs to cycloaliphatic alkoxy.

The hydroxyl value of the organic silicon modified acrylic resin is between 50 and 250 mgKOH/g; the acid value is between 0 and 20 mgKOH/g; a glass transition temperature (Tg) of between-30 ℃ and +50 ℃; the number average molecular weight is 500-20000, preferably 1500-5000; the solid content is between 70% and 100%, preferably between 75% and 90%; the B-type rotational viscosity is 0.5 to 200 pas (25 ℃), preferably 2 to 25 pas.

The organic silicon modified acrylic resin comprises the following components in parts by weight:

the solvent is selected from at least one of aliphatic ester, monohydric alcohol, ketone, dihydric alcohol ether, dihydric alcohol ester, and aromatic hydrocarbon solvent, including but not limited to the following compounds known to those skilled in the art: toluene, xylene, S-100# solvent oil, trimethylbenzene solvent oil, S-150# solvent oil, durene solvent oil, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, ethylene glycol butyl ether acetate, amyl acetate, ethylene glycol ethyl ether propionate, ethylene glycol butyl ether, ethylene glycol, n-propanol, isopropanol, n-butanol and propylene glycol methyl ether acetate.

The monomers containing carbon-carbon double bonds and capable of undergoing copolymerization reactions include, but are not limited to, the following compounds known to those skilled in the art: styrene, methyl propylene, allyl alcohol, ethylene versatate, monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, monoisopropyl maleate, mono-n-butyl maleate, mono-sec-butyl maleate, mono-tert-butyl maleate, monopentyl maleate, monohexyl maleate, monoethylhexyl maleate, bis-methyl maleate, bis-ethyl maleate, bis-n-propyl maleate, bis-isopropyl maleate, bis-n-butyl maleate, bis-sec-butyl maleate, bis-tert-butyl maleate, bis-pentyl maleate, bis-hexyl maleate, bis-ethylhexyl maleate.

The derivative of the acrylate and/or methacrylate monomer is selected from at least one of alkyl acrylate, alkyl methacrylate, cycloalkyl acrylate, cycloalkyl methacrylate, including but not limited to the following compounds known to those skilled in the art: methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, ethylhexyl acrylate, ethylhexyl methacrylate, 3, 5-trimethylhexyl acrylate, 3, 5-trimethylhexyl methacrylate, octadecyl acrylate, octadecyl methacrylate, dodecyl acrylate, dodecyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, isobornyl acrylate, isobornyl methacrylate, isopropyl methacrylate, isobutyl acrylate, Cyclohexyl acrylate, cyclohexyl methacrylate, glycidyl acrylate and glycidyl methacrylate.

The derivative of the acrylate and/or methacrylate monomer containing hydroxyl group is selected from at least one of hydroxyalkyl acrylate and hydroxyalkyl methacrylate, including but not limited to the following compounds known to those skilled in the art: 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, condensation products of acrylic acid with glycidyl versatate and condensation products of methacrylic acid with glycidyl versatate.

The derivative of acrylic acid and/or methacrylic acid containing carboxyl is selected from acrylic acid and/or methacrylic acid.

The initiator is selected from at least one of azo-type initiators or peroxy-type initiators, including but not limited to the following compounds known to those skilled in the art: azobisisobutyronitrile, azobisisoheptonitrile, benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, 1-bis (tert-amylperoxy) cyclane, 1-bis (tert-amylperoxy) -3,3, 5-trimethylcyclohexane, tert-butyl peroxybenzoate, tert-amyl peroxyacetate, 3, 5-trimethylhexanoate, ethyl 3, 3-bis (tert-butylperoxy) butyrate, ethyl 3, 3-bis (tert-amylperoxy) butyrate, dicumyl peroxide, tert-amyl hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, di-tert-amyl peroxide.

The preparation method of the organic silicon macromonomer comprises the following steps:

1) adding hexamethyldisilazane dropwise into unsaturated monohydric alcohol A, heating the system to 90-120 ℃, continuing to react for 4-8 h at the temperature, and obtaining a trimethylsiloxy unsaturated compound B through hydroxyl protection;

2) adding a catalyst into the trimethylsiloxy unsaturated compound B, and protecting the catalyst by using nitrogen, wherein the reaction temperature is as follows: at the temperature of 80-110 ℃, the reaction time is as follows: 4-12h, and then dropwise adding trimethylcyclotrisiloxane

Obtaining trimethylsiloxy alkyl modified cyclotrisiloxane after complete reaction

3) Modifying cyclotrisiloxane with trimethylsiloxy alkyl group

Hexamethylcyclotrisiloxane D₃Dissolving by using a non-polar organic solvent and a polar solvent, adding an alkyl lithium initiator, protecting by using argon in the reaction process, and reacting at the temperature: -70 ℃ to 50 ℃, reaction time: adding dimethyl hydrogen chlorosilane for end capping to obtain an organosilicon macromolecule E with a side chain having a hydroxyl protecting group and a single end having a hydrosilation group after 4-12 h;

4) mixing organosilicon macromolecules E with a hydroxyl protecting group on a side chain and a hydrosilyl group at a single end, a polymerization inhibitor and a catalyst, dripping allyl methacrylate, and protecting by nitrogen in the reaction process, wherein the reaction temperature is as follows: at the temperature of 80-110 ℃, the reaction time is as follows: obtaining an organic silicon macromonomer F with a side chain having a hydroxyl protecting group and a single end having a methacrylic group for 4-12 h;

5) adding an organic silicon macromonomer F with a side chain having a hydroxyl protecting group and a methacrylic group at a single end into an alcohol solvent, and reacting by taking weak acid as a catalyst at the reaction temperature of: 65-100 ℃, and the reaction time is as follows: and (4) distilling under reduced pressure for 4-12h to remove alcohol compounds and low-boiling-point substances, thereby obtaining the organic silicon macromonomer G with the side chain having the hydroxyl alkyl group and the single end having the methacrylic acid group.

The molar ratio of the unsaturated monohydric alcohol A to the hexamethyldisilazane is 2 (1-2), preferably 2 (1-1.1).

The unsaturated monohydric alcohol A is selected from one of the following structures:

A₁)CH₂＝CHCH₂OH A₂)CH₂＝CHCH₂CH₂OH A₃)CH₂＝CHCH₂CH₂CH₂OH

A₄)CH₂＝CHCH₂CH₂CH₂CH₂OH A₅)CH₂＝CHCH₂OCH₂CH(OH)CH₂OCH₃。

the trimethylsiloxy unsaturated compound B is selected from one of the following structures:

B₁)CH₂＝CHCH₂OSi(CH₃)₃B₂)CH₂＝CHCH₂CH₂OSi(CH₃)₃B₃)CH₂＝CHCH₂CH₂CH₂OSi(CH₃)₃

B₄)CH₂＝CHCH₂CH₂CH₂CH₂OSi(CH₃)₃B₅)CH₂＝CHCH₂OCH₂CH[OSi(CH₃)₃]CH₂OCH₃。

the catalyst is chloroplatinic acid.

The trimethyl siloxy unsaturated compound B and trimethyl cyclotrisiloxane

The molar ratio of (a) to (b) is 3:1 to 6:1, preferably 3:1 to 3.3: 1.

The mass of the catalyst accounts for 0.05-1% of that of the trimethylcyclotrisiloxane.

The trimethylsiloxy alkyl modified cyclotrisiloxane

The structure of (a) is as follows:

T₁)CH₂CH₂CH₂OSi(CH₃)₃T₂)CH₂CH₂CH₂CH₂OSi(CH₃)₃T₃)CH₂CH₂CH₂CH₂CH₂OSi(CH₃)₃

T₄)CH₂CH₂CH₂CH₂CH₂CH₂OSi(CH₃)₃T₅)CH₂CH₂CH₂OCH₂CH[OSi(CH₃)₃]CH₂OCH₃。

the mass ratio of the nonpolar organic solvent to the polar solvent is 1: 1-1: 5, and the total mass of the nonpolar organic solvent and the polar solvent is equal to that of the trimethylsiloxy alkyl modified cyclotrisiloxane

Hexamethylcyclotrisiloxane D₃And the total mass ratio of the alkyl lithium is 1: 4-4: 1.

The molar ratio of the alkyl lithium initiator to the dimethyl hydrogen chlorosilane is 1: 1-1: 1.2; trimethylsiloxyalkyl-modified cyclotrisiloxanes in the preparation process

Hexamethylcyclotrisiloxane D₃And alkyllithium the molar ratios of the 3 reactants fed depend on the molecular weight of the final product.

Referring to the molecular structure in example 9, the molecular weight design formula (taking n-butyllithium as an initiator and using 1mol as an example) is as follows:

designed molecular weight of silicone macromolecule E ═ molecular weight of n-butyl (57) + D^T ₃Molecular weight XD^T ₃Amount of (n ═ x/3) + D₃Molecular weight of (2) XD₃Amount of (m) ═ y/3) + (CH3)₂The molecular weight of SiH (59), i.e., M57 +60y +190x + 59.

If the molecular weight is about 1000 and x and y in the above reaction formula are 1 and 12 respectively, n and m are about 1/3 and 4 respectively, namely 1mol of initiator and 1/3mol of D are needed for preparing organosilicon macromolecule E with molecular weight of about 1000^T ₃And 4mol of D₃。

The designed molecular weight of the organosilicon macromolecule E with the side chain having a hydroxyl protecting group and the single end having a hydrosilation group is M_{Lithium removal molecular weight of alkyllithium initiators}+D^T ₃Molecular weight XD^T ₃Amount of substance (c) + D₃Molecular weight of (2) XD₃Amount of substance(s) + M_{Dimethyl hydrogen chlorosilane}。

The non-polar organic solvent is selected from at least one of aliphatic hydrocarbon solvent, alicyclic hydrocarbon solvent and aromatic hydrocarbon solvent, including but not limited to the following compounds known to those skilled in the art: isopentane, n-pentane, petroleum ether, n-hexane, cyclohexane, isooctane, cyclopentane, trimethylpentane, cyclopentane, heptane, toluene, benzene, xylene.

The alkyl lithium initiator is selected from at least one of n-butyl lithium, sec-butyl lithium, tert-butyl lithium and trimethylsiloxy lithium.

The polar solvent is selected from at least one of aliphatic ketones, alicyclic ketones, aromatic ketones, amides, sulfoxides, nitriles, heterocyclic solvents, including but not limited to the following compounds known to those skilled in the art: tetrahydrofuran, formamide, acetonitrile, N-dimethylformamide, hexamethylphosphoramide, butanone, dimethyl sulfoxide, acetone, 1, 4-dioxane and pyridine.

The dimethyl hydrochlorosilane is dimethyl monochlorosilane.

The number average molecular weight of the organosilicon macromolecule E with the side chain having a hydroxyl protecting group and the single end having a hydrosilation group is between 500 and 4500, and the organosilicon macromolecule E has the following structure:

wherein: y >0, x > 0.

The mass of the polymerization inhibitor accounts for 0.1-5% of the mass of the allyl methacrylate.

The mass of the catalyst accounts for 0.05-1% of that of the organic silicon macromolecule E with a hydroxyl protecting group at a side chain and a hydrosilyl group at a single end.

The molar ratio between the organosilicon macromolecule E with the hydroxyl protecting group on the side chain and the hydrosilyl group at a single end and allyl methacrylate is mainly referred to the molar ratio between an Si-H group in the organosilicon macromolecule E with the hydroxyl protecting group on the side chain and a C ═ C group in allyl methacrylate, namely the molar ratio between the allyl methacrylate and the hydrosilyl group (Si-H) contained in the organosilicon macromolecule E with the hydroxyl protecting group on the side chain and the hydrosilyl group at a single end is 1: 1-2: 1, preferably 1.01: 1-1.05: 1.

The polymerization inhibitor is selected from phenolic and quinone polymerization inhibitors, including but not limited to the following compounds known to those skilled in the art: hydroquinone, p-benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tertiary butyl hydroquinone and 2, 5-di-tertiary butyl hydroquinone.

The catalyst is selected from chloroplatinic acid.

The organic silicon macromonomer F with a side chain provided with a hydroxyl protecting group and a methacrylic acid group at a single end has the following structure:

wherein y >0 and x > 0.

The mass ratio of the organic silicon macromonomer F with the side chain provided with the hydroxyl protecting group and the single end provided with the methacrylic group to the alcohol solvent is 1: 1-1: 4.

The mass of the weak acid accounts for 0.5-5% of that of the organosilicon macromonomer F with a hydroxyl protecting group on a side chain and a methacrylic acid group on a single end.

The alcohol solvent is at least one selected from methanol, ethanol, n-propanol and isopropanol.

The weak acid is at least one selected from formic acid, acetic acid, propionic acid, lactic acid, dimethylolpropionic acid and dimethylolbutyric acid.

Another aspect of the present invention provides a preparation method of the silicone modified acrylic resin with high solid content and low viscosity, including the following steps:

mixing 25-200 parts of a monomer which contains carbon-carbon double bonds and can be subjected to copolymerization reaction, 200-500 parts of a derivative of an acrylate and/or methacrylate monomer, 150-250 parts of a derivative of a hydroxyl-containing acrylate and/or methacrylate monomer, 1-20 parts of a derivative of carboxyl-containing acrylic acid and/or methacrylic acid, 25-100 parts of an organosilicon macromonomer and 14-70 parts of an initiator, adding the mixture into 100-200 parts of a solvent for reaction at the temperature of 80-200 ℃ for 4-20 hours, and obtaining the organosilicon modified acrylic resin with high solid content and low viscosity.

The crosslinking curing agent is 10-40 parts of alkylated melamine formaldehyde resin;

or 10 to 40 parts of alkylated melamine formaldehyde resin and 0.1 to 10 parts of amino resin with carbamate functional group;

or 10-40 parts of alkylated melamine formaldehyde resin and 0.1-20 parts of blocked aliphatic isocyanate;

or 10 to 40 parts of alkylated melamine formaldehyde resin, 0.1 to 10 parts of amino resin with carbamate functional group and 0.1 to 20 parts of blocked aliphatic isocyanate.

When the crosslinking curing agent is alkylated melamine-formaldehyde resin, the butyl ether type imino-containing melamine-formaldehyde resin existing in a polymer form is preferred, the equivalent weight is 200-280, and the parts of the crosslinking curing agent in the high-scratch-resistant and high-weather-resistant single-component varnish composition are 10-40 parts; the melamine-formaldehyde resin may be selected from a mixed etherified type, imino-containing type, and a melamine-formaldehyde resin in the form of an oligomer and/or a mixed etherified type, all etherified modified, and monomer. When the mixed etherified, imino-containing, melamine-formaldehyde resin present as an oligomer and/or the mixed etherified, fully etherified, modified melamine-formaldehyde resin present as a monomer are used, they should be used in an amount of not more than 50% by weight based on the total amount of the alkylated melamine-formaldehyde resin.

The crosslinking curing agent also can further comprise amino resin containing an alkoxy carbonyl amino triazine compound structure and having carbamate functional groups, and the part of the amino resin having the carbamate functional groups in the high-scratch-resistant and high-weather-resistant single-component varnish composition is 0.1-10 parts; the cross-linking curing agent can further select closed aliphatic isocyanate, and the parts of the closed aliphatic isocyanate in the high-scratch-resistant and high-weather-resistant single-component varnish composition are 0.1-20 parts.

In the present invention, the alkylated melamine formaldehyde resin may be selected from all relevant brands of commercial products produced by nepesin (suzhou) ltd, basf (china) ltd and zhanxin (shanghai) ltd, such as: setalux US138BB70 and Setalux US146BB72 from Nepetes resins (Suzhou) Ltd, Luwipol 072 and Luwipol 052 from Pasteur resins (China) Ltd, and Cymel 325, Cymel 1168 and Cymel 303 from Zun resins (Suzhou) Ltd. The amino resin having carbamate functional groups may be chosen from all relevant brands of commercial products manufactured by basf (china) limited and the Zhan new resins (su) limited, for example: larotact 150 from Pasteur (China) Ltd, Cymel NF2000 from New resins (Suzhou) Ltd. The blocked aliphatic isocyanate may be selected from all relevant grades of commercial products manufactured by bayer (china) limited, for example: desmodur BL3575, Desmodur BL3475 and Desmodur BL 3175.

The acid catalyst is a sulfonic acid type catalyst containing free and blocked sulfonic acid groups; in the high scratch-resistant and high weather-resistant single-component varnish composition, the acid catalyst is 0.1-3 parts. For purposes of the present invention, the acid catalyst may be selected from all relevant brands of commercial products manufactured by King industries and Zhan New resins (Suzhou) Inc., such as: nacure 2500, Nacure 5225, Nacure 3525 and Nacure5414 from King industries, Cycat 4040, Cycat 500 and Cycat 600 from Zusan Ltd.

The rheology control agent can select compounds containing urea bonds, polymers and related derivatives thereof, and/or high molecular fine particles with a cross-linked structure, and/or fine silica particles with surface treated; the polyurea and the derivative thereof are prepared by preferably modifying polyester or polyacrylic resin as a main body, and in the high-scratch-resistant and high-weather-resistant single-component varnish composition, the parts of the rheological control agent are 5-30 parts. For the purposes of the present invention, the rheology control agent may be chosen from all relevant brands of commercial products manufactured by nepes resins (suzhou) limited, such as: setalux 61767, Setalux 91757 and Setalux 91760 from Nepetes resin, Inc., Suzhou, and similar products from other companies may be selected.

The auxiliary is typically selected from at least one of leveling control agents, uv absorbers, and hindered amine light stabilizers.

Preferably, the leveling control agent may be selected from all relevant brands of commercial products manufactured by bibk chemical technical counseling (shanghai) ltd, germany, for example: BYK 310, BYK 315, BYK 320, BYK 325, BYK 331, BYK358N, BYK 3550, and BYK 3560, and similar products from other companies may be selected.

Preferably, for the agents of uv absorbers and hindered amine light stabilizers, reference is made to commercial products selected from all relevant brands produced by basf (china) limited, such as: tinuvin 292, Tinuvin 1130 and Tinuvin123, and similar products produced by other companies can be selected.

Preferably, the auxiliary agent can also be addedOne step comprises an antioxidant and an anti-settling agent; the antioxidant and anti-settling agent may be referred to as commercial products selected from all relevant brands manufactured by basf (china) limited, for example: irgafos168 and

963S; similar products from other companies may also be selected. Wherein the amount of the antioxidant depends on the resin used for different purposes, and the amount of the anti-settling agent depends on the amount of the pigment. When it is desired to use the aforementioned antioxidants and anti-settling agents, it is also desirable to uniformly mix them with the other components of the adjuvant.

The solvent is at least one of aliphatic ester, ketone, dihydric alcohol ether, dihydric alcohol ester, aromatic hydrocarbon solvent, etc.; including but not limited to the following compounds known to those skilled in the art: toluene, xylene, S-100# solvent oil, trimethylbenzene solvent oil, S-150# solvent oil, durene solvent oil, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, ethylene glycol butyl ether acetate, amyl acetate, ethylene glycol ethyl ether propionate, ethylene glycol butyl ether and ethylene glycol.

Another aspect of the present invention provides a preparation method of the high scratch resistance and high weather resistance one-component varnish composition, specifically a preparation method of a high solid content varnish prepared by mixing a polymer with a hyperbranched or dendritic structure, a hydroxy acrylic resin or a hydroxy methacrylic resin, a crosslinking curing agent, a rheology control agent and other components, comprising the following steps (taking preparation of 1kg of varnish sample as an example):

firstly, stirring and mixing 0.5-10 parts of solvent and 1-20 parts of polymer with hyperbranched or dendritic structure uniformly;

secondly, adding 5-50 parts of hydroxyl acrylic resin or hydroxyl methacrylic resin and 1-20 parts of organic silicon modified acrylic resin, and uniformly stirring and mixing;

thirdly, under the condition that the stirring speed is kept unchanged, sequentially adding 1-10 parts of an auxiliary agent, 5-30 parts of a rheological control agent and 10-70 parts of a crosslinking curing agent, and uniformly stirring and mixing;

and fourthly, under the condition that the stirring speed is kept unchanged, adding 0.1-3 parts of acid catalyst and 0.5-32 parts of solvent, and stirring and mixing uniformly to obtain the single-component varnish composition.

The stirring and mixing are uniform, namely the stirring speed is 400-1000 revolutions per minute (r/min), and the stirring time is 10-60 min.

And in the third step, the time interval for sequentially adding the auxiliary agent, the rheological control agent and the crosslinking curing agent is 5-8 min.

In a further aspect of the invention, the use of the high scratch-resistant and high weathering resistance one-component varnish composition as an overprint varnish is provided. The use of the high scratch-resistant and high weathering one-component varnish composition as an overprint varnish comprises the following steps: the highly scratch-resistant and highly weather-resistant one-component varnish composition is applied to a pre-coated substrate and cured at a temperature of 80 to 180 ℃ to form a varnish coating.

The substrate is a standard automotive body or component assembly of an automotive body, and is prepared from a cold-rolled sheet which is chemically pre-treated and covered with an electrophoretic coating.

In a further aspect of the invention, there is provided the use of the high scratch-resistant and high weathering resistance one-component varnish composition for the preparation of a multicoat finish system; the multi-coat finishing system comprises at least one color coat and at least one clear coat, wherein the clear coat is the outermost coat of the multi-coat finishing system and is prepared from the single-component clear coat composition.

Preferably, the use of the high scratch-resistant and high weathering single-component varnish composition for the preparation of a multicoat finish system further comprises the following steps:

applying a base coat or intermediate coat paint to a substrate and curing it, applying a basecoat paint to said substrate with the basecoat or intermediate coat already cured, then applying said one-component clear coat composition to the uncured basecoat surface, and finally curing both part coats simultaneously to obtain said multi-coat finish system, which can be used in a three-coat two-bake system;

alternatively, the first and second electrodes may be,

applying a primer or a basecoat to a substrate, applying a basecoat to the surface of the uncured primer or basecoat, applying a single component clear coat composition to the surface of the uncured basecoat, and simultaneously curing the three coats to obtain the multi-coat finishing system, wherein the multi-coat finishing system can be used in a three-coat one-bake system or an integrated spray process system;

alternatively, the first and second electrodes may be,

applying two coats of pigmented paint to a substrate without a primer and a basecoat, then spraying the one-component, high scratch and weathering varnish composition on the surface of the second coat of pigmented paint and simultaneously curing the three coats to obtain the multi-coat finishing system, which can be used in a compact spray process system;

alternatively, the first and second electrodes may be,

applying a primer or a mid-coat paint to a substrate and curing it, then applying a single-color paint to said substrate with the primer or mid-coat already cured, then applying a pearlescent paint to the uncured surface of the mono-color paint coating, then applying said high scratch and weather resistant one-component clear coat composition to the uncured pearlescent paint surface, and finally curing the three part coatings simultaneously to obtain said multi-coat finishing system, which can be used in a four coat two bake system;

alternatively, the first and second electrodes may be,

the method comprises the steps of firstly applying a primer or a middle coat on a substrate, then applying a single-component varnish to the surface of an uncured primer or middle coat, then applying a pearlescent paint to the surface of an uncured single-component varnish coat, then applying the high-scratch-resistant and high-weather-resistant single-component varnish composition to the surface of the uncured pearlescent paint, and finally curing the four parts of the coat simultaneously to obtain the multi-coat finishing system, wherein the multi-coat finishing system can be used for a four-coat one-bake system.

The priming paint and/or the colored paint used in the three-coating two-baking, three-coating one-baking or integrated spraying process, the compact spraying process, the four-coating two-baking and four-coating one-baking system are water-based paint or solvent-based paint, and the construction solid content of the priming paint and/or the colored paint is between 25 and 55 percent; the colored paint is at least one of a single-color paint, a metal paint or a flashing paint, is a water-based colored paint or a solvent-based colored paint, and has a cured film thickness of 5-40 μm, and further 5-30 μm.

The primer or the middle paint is a water-based or solvent-based primer or middle paint; the cured film has a thickness of 10 to 50 μm, and further 15 to 40 μm.

The dry film thickness of the multi-coat coating system is 10 to 80 μm, preferably 20 to 70 μm, and more preferably 30 to 60 μm; the temperature of the heating and curing is 100-180 ℃, and preferably 120-160 ℃; the heating and curing time is 10-40 min.

Due to the adoption of the technical scheme, the invention has the following advantages and beneficial effects:

the main chain of the organic silicon in the organic silicon modified acrylic resin is a Si-O-Si bond, and is not easy to decompose by ultraviolet light and ozone, so that the organic silicon has better irradiation resistance and weather resistance than other high polymer materials, and therefore, when the organic silicon modified acrylic resin is added into a varnish composition as a coating component, the weather resistance of a coating film and the color and light retention of the coating film can be further improved; in addition, since the organosilicon modified acrylic resin used in the present invention does not contain Si-O-C bonds which are easily hydrolyzed, the molecular structure of the resin can be kept stable in a moist heat state, and the organosilicon modified acrylic resin has excellent weather resistance stability against UV rays, particularly in a dry-wet alternating environment.

The organic silicon in the organic silicon modified acrylic resin has the characteristics of weak surface tension, small surface energy, strong film forming capability and the like, so that when the organic silicon modified acrylic resin is added into a paint film, the paint film can be endowed with good scratch resistance and stain resistance, and meanwhile, the paint film has good smooth hand feeling.

The organic silicon modified acrylic resin has weaker intermolecular force of organic silicon than hydrocarbon, so compared with the hydrocarbon with the same molecular weight, the organic silicon has the advantage of low viscosity, and the viscosity of the acrylic resin can be effectively reduced after organic silicon is introduced into the molecules of the acrylic resin by chain forging. After a certain amount of organic silicon modified acrylic resin is introduced into the varnish composition, the construction solid content of the varnish composition is improved, and the construction viscosity of the varnish composition can be further reduced.

The main chain of the organic silicon in the organic silicon modified acrylic resin is very flexible, and when the organic silicon modified acrylic resin is introduced into the varnish composition, the flexibility of a paint film can be adjusted, so that the paint film has good impact property; in addition, the side chain of the organosilicon molecule contains hydroxyl which can react with the curing agent, so that the adverse effect of poor adhesion of recoating caused by the introduction of organosilicon chain segments is avoided when recoating is carried out.

The high scratch resistance and high weather resistance single-component varnish composition provided by the invention has a storage stable period of 3-6 months (depending on storage conditions).

The high scratch-resistant and high weather-resistant single-component varnish composition provided by the invention can be selectively and respectively matched with a colored pigment, a metal pigment and a flashing pigment to be used as a single-color paint, a metal paint or a flashing paint.

The high-scratch-resistant and high-weather-resistant single-component varnish composition provided by the invention can effectively improve the smoothness of the coating surface of the varnish composition, so that the friction resistance of the coating is improved; in addition, the introduction of the silicone modified acrylic resin can further improve the weather resistance of the varnish composition coating film.

Detailed Description

The present invention will be further described with reference to specific embodiments in order to make the original features, technical means and objectives of the invention easier to understand. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

In the case where the objects of the present invention are illustrated and explained by the following examples, the components of the composition are all explained on the general standard of parts by weight. In the present invention, the terms "part by weight" and "part" are used synonymously in the examples for the sake of brevity without specific mention.

Example 1

Preparation of polymers having hyperbranched or dendritic structures

354.8g of Boltorn H40 and 74g of hexahydrophthalic anhydride were charged in a 1L reaction vessel equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux condenser, and then the reaction system was warmed to 130 ℃. After the reaction temperature is constant, continuously keeping the temperature for 4-5 h at the temperature, sampling every 1h during the period to measure the acid value, when the measured value of the acid value (63mgKOH/g) reaches the theoretical value (62.8mgKOH/g), adding 115.2g of tertiary carbonic acid glycidyl ester with the epoxy equivalent of 240 and 0.5g of N, N-dimethylbenzylamine, and continuously keeping the temperature for 4-5 h at the temperature. And continuously monitoring the change of the acid value in the heat preservation process, and stopping the reaction when the acid value is less than 2 mgKOH/g. And when the reaction temperature is reduced to 110 ℃, adding butyl acetate for viscosity reduction and adjusting the solid content to finally obtain 804g of the polymer with the solid content of 65 percent and the hyperbranched or dendritic structure.

Example 2

Preparation of polymers having hyperbranched or dendritic structures

354.8g of Boltorn H40 and 98.6g of hexahydrophthalic anhydride were charged in a 1L reaction vessel equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux condenser, and then the reaction system was warmed to 130 ℃. After the reaction temperature is constant, continuously keeping the temperature for 4-5 h, sampling every 1h to measure the acid value, when the measured value of the acid value (79mgKOH/g) reaches the theoretical value (79.2mgKOH/g), adding 153.6g of tertiary carbonic acid glycidyl ester with the epoxy equivalent of 240 and 0.5g of N, N-dimethylbenzylamine, and continuously keeping the temperature for 4-5 h. And continuously monitoring the change of the acid value in the heat preservation process, and stopping the reaction when the acid value is less than 2 mgKOH/g. When the reaction temperature is reduced to 110 ℃, butyl acetate is added for viscosity reduction and solid content is adjusted, and 912g of polymer with hyper branched or tree-like structure with solid content of 65 percent is finally obtained.

Example 3

Preparation of epoxy modified hyperbranched polyester resin

The preparation is carried out by referring to a synthesis method described in the first example of patent CN104628995, and the specific synthesis steps are as follows: 354.8g of Boltorn H40 and 74g of hexahydrophthalic anhydride were charged in a 1L reaction vessel equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux condenser, and then the reaction system was warmed to 130 ℃. After the reaction temperature is constant, continuously keeping the temperature for 4-5 h at the temperature, sampling every 1h during the period to measure the acid value, when the measured value of the acid value (63mgKOH/g) reaches the theoretical value (62.8mgKOH/g), adding 134.4g of 1, 4-butanediol diglycidyl ether with the epoxy equivalent of 140 and 0.6g of triphenylphosphine, and continuously keeping the temperature for 4-5 h at the temperature. During the incubation, the acid value and epoxy equivalent changes were continuously monitored and the reaction stopped when the acid value was less than 2mgKOH/g and the epoxy equivalent was close to 1200. And when the reaction temperature is reduced to 110 ℃, adding butyl acetate for viscosity reduction and adjusting the solid content to finally obtain 845g of epoxy modified hyperbranched polyester resin with the solid content of 65 percent.

Example 4

Preparation of epoxy modified hyperbranched polyester resin

The preparation is carried out by referring to a synthesis method described in the first example of patent CN104628995, and the specific synthesis steps are as follows: 354.8g of Boltorn H40 and 98.6g of hexahydrophthalic anhydride were charged in a 1L reaction vessel equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux condenser, and then the reaction system was warmed to 130 ℃. After the reaction temperature is constant, keeping the temperature for 4-5 h, sampling every 1h to measure the acid value, when the measured value of the acid value (79mgKOH/g) reaches the theoretical value (79.2mgKOH/g), adding 204.8g of 1, 6-hexanediol diglycidyl ether with the epoxy equivalent of 160 and 0.6g of triphenylphosphine, and keeping the temperature for 4-5 h. During the incubation, the acid value and epoxy equivalent changes were continuously monitored and the reaction was stopped when the acid value was less than 2mgKOH/g and the epoxy equivalent was close to 1000. And when the reaction temperature is reduced to 110 ℃, adding butyl acetate for viscosity reduction and adjusting the solid content to finally obtain 983g of epoxy modified hyperbranched polyester resin with the solid content of 65 percent.

Example 5

Preparation of blocked isocyanate modified hyperbranched polyester resin

The preparation is carried out by referring to a synthesis method described in the first example of patent CN104893533, and the specific synthesis steps are as follows:

and (3) blocking reaction: 444g of isophorone diisocyanate was charged into a 2L reaction vessel equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux condenser, and then the reaction system was heated to 70 ℃. When the temperature is constant, slowly adding 235.04g of caprolactam dissolved in 200g of cyclohexanone dropwise, controlling the reaction temperature in the dropwise adding process, and keeping the temperature not to exceed 80 ℃. And after the dropwise addition, continuously reacting for 4-5 h at the temperature, and analyzing the content of the residual isocyanate group in the reaction system. When the residual isocyanate group content reached the theoretical value of 9.17%, the reaction was stopped and 860g of caprolactam half-blocked isocyanate having a solids content of 77% were obtained by discharge.

Modification of blocked isocyanate: 354.8g of Boltorn H40 and 250g of cyclohexanone were added to a 2L reactor equipped with a stirrer, a thermometer, a nitrogen conduit and a reflux condenser, and the reaction system was heated to 110 ℃ and, after Boltorn H40 was completely dissolved, the reaction system was cooled to 80 ℃. When the temperature of the reaction system is kept stable at 80 ℃, 366g of caprolactam semi-blocked isocyanate with 77 percent of solid content is dripped, and the temperature is kept not more than 80 ℃ in the dripping process. Continuing the reaction at the temperature for 4-5 h after the dropwise addition, sampling every 1h, and observing the wave number of about 2200cm by infrared spectroscopy^-1And (4) whether the infrared characteristic absorption peak of the isocyanate group disappears or not is judged, and after the characteristic absorption peak disappears completely, heating is stopped, so that 940g of the blocked isocyanate modified hyperbranched polyester resin with the solid content of 65.5 percent is obtained.

Example 6

Preparation of blocked isocyanate modified hyperbranched polyester resin

and (3) blocking reaction: 444g of isophorone diisocyanate was charged into a 2L reaction vessel equipped with a stirrer, a thermometer, a nitrogen introduction tube and a reflux condenser, and then the reaction system was heated to 70 ℃. After the temperature is constant, 181g of methyl ethyl ketoxime is slowly dripped, the reaction temperature is controlled in the dripping process, and the temperature is kept not to exceed 80 ℃. And after the dropwise addition, continuously reacting for 4-5 h at the temperature, and analyzing the content of the residual isocyanate group in the reaction system. When the content of the residual isocyanate group reaches 12.9 percent of the theoretical value, stopping the reaction, reducing the viscosity by using butyl acetate, and discharging to obtain 775g of methyl ethyl ketoxime semi-closed isocyanate with the solid content of 80 percent.

Modification of blocked isocyanate: 354.8g of Boltorn H40 and 250g of cyclohexanone were added to a 2L reactor equipped with a stirrer, a thermometer, a nitrogen conduit and a reflux condenser, and the reaction system was heated to 110 ℃ and, after Boltorn H40 was completely dissolved, the reaction system was cooled to 80 ℃. When the temperature of the reaction system is kept stable at 80 ℃, 250g of caprolactam semi-blocked isocyanate with the solid content of 80 percent is dripped, and the temperature is kept not more than 80 ℃ in the dripping process. Continuing the reaction at the temperature for 4-5 h after the dropwise addition, sampling every 1h, and observing the wave number of about 2200cm by infrared spectroscopy^-1And (3) whether the infrared characteristic absorption peak of the isocyanate group disappears or not is judged, and after the characteristic absorption peak disappears completely, the heating is stopped, and 833g of the blocked isocyanate modified hyperbranched polyester resin with the solid content of 64.9 percent is obtained.

Example 7

Preparation of hydroxy (meth) acrylic resins

Firstly, 1250g of a mixed solvent of xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:1) is added into a 10L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 500g of styrene, 2250g of n-butyl acrylate, 1750g of hydroxyethyl methacrylate, 50g of acrylic acid, 450g of methyl methacrylate and 310g of tert-butyl peroxy-2-ethyl hexanoate into a reaction kettle by a peristaltic pump, maintaining the reaction temperature between 130 and 140 ℃ in the dropwise adding process, and controlling the dropwise adding speed to ensure that the dropwise adding of the reaction mixture is completed within 2 to 4 hours. After the dropwise addition, continuously preserving the heat for 2-4 h at 130-140 ℃, and terminating the reaction to obtain the hydroxyl acrylic resin with the solid content of 80%, the hydroxyl value of 150mgKOH/g, the glass transition temperature (Tg) of 0 ℃ and the number average molecular weight of 3500 or so.

Example 8

Preparation of hydroxy (meth) acrylic resins

Firstly, 1250g of mixed solvent of xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:1) is added into a 10L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 500g of styrene, 1750g of n-butyl acrylate, 1750g of hydroxyethyl methacrylate, 50g of acrylic acid, 950g of methyl methacrylate and 432g of tert-butyl peroxy-2-ethyl hexanoate into a reaction kettle by a peristaltic pump, maintaining the reaction temperature between 130 and 140 ℃ in the dropwise adding process, and controlling the dropwise adding speed to ensure that the dropwise adding of the reaction mixture is completed within 2 to 4 hours. After the dropwise addition, continuously keeping the temperature at 130-140 ℃ for 2-4 h, and terminating the reaction to obtain the hydroxyl acrylic resin with the solid content of 80%, the hydroxyl value of 150mgKOH/g, the glass transition temperature (Tg) of 15 ℃ and the number average molecular weight of 2500 or so.

Example 9

Hydroxyl protection: 338.1g (2.1mol) of hexamethyldisilazane were slowly added dropwise to 232g (4mol) of allyl alcohol in a 1L reactor at room temperature. After the dropwise addition, the reaction system was heated to 100 ℃ and continued to react at this temperature for 6 hours, and then the reaction was stopped. The 98-100 ℃ fraction was collected under normal pressure to obtain 473.2g of allyloxytrimethylsilane (91% yield).

Primary hydrosilylation: in a 1L reactor, 393.9g (3.03mol) of allyloxytrimethylsilane and 0.5g of chloroplatinic acid catalyst (0.5/180 ═ 0.27%) were sequentially charged, and after introducing nitrogen gas for 20min, the reaction system was heated to 100 ℃ and 180g (1mol) of trimethylcyclotrisiloxane was added dropwise thereto and reacted for 8 hours, followed by termination of the reaction. The low boiling point substance was distilled off under reduced pressure to obtain 553g of trimethylsiloxyalkyl-modified cyclotrisiloxane in a yield of 97.0%.

Anionic polymerization: 1mol of n-butyllithium, 740g (3.333mol) of hexamethylcyclotrisiloxane, 190g (0.333mol) of trimethylsiloxyalkyl modified cyclotrisiloxane, 500g of n-hexane and tetrahydrofuran (mass ratio is 1:1) are sequentially added into a 2L reaction kettle after anhydrous and anaerobic treatment, stirred at 25 ℃ for 8 hours, and then added with 1.1mol of dimethylchlorosilane for terminating the reaction. And (3) filtering the reaction liquid to remove the generated lithium chloride, and distilling under reduced pressure to remove low-boiling-point substances to obtain 987g of organosilicon macromolecules with the number average molecular weight of about 1026, wherein the side chains of the organosilicon macromolecules have hydroxyl protecting groups and the single ends of the organosilicon macromolecules have hydrosilyl groups, and the yield is 96.2%.

Secondary hydrosilylation: 615.6g (0.6mol of Si-H group) of organosilicon macromolecule with a side chain provided with a hydroxyl protecting group and a hydrosilyl group at a single end, 0.38g of p-hydroxyanisole polymerization inhibitor and 1g of chloroplatinic acid catalyst are sequentially added into a 1L reaction kettle, after nitrogen is introduced for 20min, the reaction system is heated to 100 ℃, 74.4g (0.6mol of C ═ C double bond group) of allyl methacrylate is dropwise added at the temperature, and the reaction is terminated after 5H of reaction. The low-boiling residue was distilled off under reduced pressure to obtain 662g of an organosilicon macromonomer having a hydroxyl protecting group on the side chain and a methacrylic group at the single end, and the yield was 95.9%. In the above reaction, the molar ratio of allyl methacrylate to hydrosilyl group (Si-H) was 1:1.

Alcoholysis reaction: 345g of an organosilicon macromonomer with a side chain having a hydroxyl protecting group and a methacrylic acid group at a single end, 500g of methanol and 3g of acetic acid were sequentially added to a 1L reaction kettle. The reaction was stopped after 9h at 65 ℃ under reflux. Acetic acid, excessive methanol and low-boiling-point substances are removed by reduced pressure distillation, 320g of organosilicon macromonomer with side chain of hydroxyalkyl and single end of methacrylic group with number average molecular weight about 1078 is obtained, and the yield is 98.9%.

Example 10

Hydroxyl protection: 338.1g (2.1mol) of hexamethyldisilazane were slowly added dropwise to 288g (4mol) of 3-buten-1-ol in a 1L reactor at room temperature. After the dropwise addition, the reaction system was heated to 100 ℃ and continued to react at this temperature for 6 hours, and then the reaction was stopped. The 110 ℃ and 115 ℃ fractions were collected at atmospheric pressure to give 558g of vinylbutoxytrimethylsilane in a 96.9% yield.

Primary hydrosilylation: 436.3g (3.03mol) of vinylbutoxytrimethylsilane and 0.5g of chloroplatinic acid catalyst were sequentially added to a 1L reaction vessel, and after introducing nitrogen gas for 20min, the reaction system was heated to 100 ℃ and 180g (1mol) of trimethylcyclotrisiloxane was added dropwise thereto at this temperature to react for 8 hours, and the reaction was terminated. The low boiling point substance was distilled off under reduced pressure to obtain 601g of trimethylsiloxyalkyl-modified cyclotrisiloxane in a yield of 98.2%.

Anionic polymerization: 1mol of n-butyllithium, 518g (2.333mol) of hexamethylcyclotrisiloxane, 408g (0.666mol) of trimethylsiloxyalkyl-modified cyclotrisiloxane, 500g of n-hexane and tetrahydrofuran (mass ratio of 1:1) are sequentially added into a 2L reaction kettle which is subjected to anhydrous and anaerobic treatment, stirred at 25 ℃ for 8 hours, and then added with 1.1mol to terminate the reaction. The reaction solution was filtered to remove the generated lithium chloride, and after low boiling point substances were removed by distillation under reduced pressure, 975g of an organosilicon macromolecule having a hydroxyl protecting group at a side chain and a hydrosilyl group at a single end of 1022 number average molecular weight was obtained with a yield of 95.4%.

Secondary hydrosilylation: 600g (0.6mol of Si-H group) of organic silicon macromolecule with a hydroxyl protecting group on a side chain and a hydrosilyl group on a single end, 0.38g of p-benzoquinone polymerization inhibitor and 1g of chloroplatinic acid catalyst are sequentially added into a 1L reaction kettle, after nitrogen is introduced for 20min, the reaction system is heated to 100 ℃, 74.4g (0.6mol of C ═ C double bond group) of allyl methacrylate is dropwise added at the temperature, and the reaction is terminated after 5H of reaction. Vacuum distillation is carried out to remove low-boiling-point substances, 640g of organosilicon macromonomer with a side chain having a hydroxyl protecting group and a single end having a methacrylic acid group and a number average molecular weight of about 1146 is obtained, and the yield is 94.9%. The mol ratio of allyl methacrylate to the hydrosilyl group (Si-H) contained in the organosilicon macromolecule E with a hydroxyl protecting group at the side chain and a hydrosilyl group at the single end is 1:1.

Alcoholysis reaction: in a 2L reactor, 458.4g of an organosilicon macromonomer having a hydroxyl-protecting group in the side chain and a methacrylic group at the single terminal, 800g of methanol and 5g of acetic acid were sequentially added. The reaction was stopped after 9h at 65 ℃ under reflux. Acetic acid, excessive methanol and low-boiling-point substances are removed by reduced pressure distillation, 410g of organosilicon macromonomer with a side chain of hydroxyalkyl and a single end of methacrylic group with the number average molecular weight of about 1074 is obtained, and the yield is 95.3%.

Example 11

Firstly, 125g of a mixed solvent of xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:1) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 50g of styrene, 225g of n-butyl acrylate, 175g of 2-hydroxyethyl methacrylate, 5g of acrylic acid, 45g of methyl methacrylate, 26.3g of the organosilicon macromonomer prepared in example 9 and 38g of tert-butyl peroxy-2-ethylhexanoate into a reaction kettle by a peristaltic pump, maintaining the reaction temperature at 130-140 ℃ in the dropwise adding process, and controlling the dropwise adding speed to ensure that the dropwise adding of the reaction mixture is completed within 2-4 h. After the dropwise addition is finished, continuously preserving the heat for 2-4 h at 130-140 ℃, and terminating the reaction to obtain organic silicon modified acrylic resin with the solid content of 80.8%, the hydroxyl value of 143mg KOH/g, the organic silicon content of 5%, the B-type rotational viscosity of 25Pa s and the number average molecular weight of 3000, and the acid value of 7.4mg KOH/g; the glass transition temperature (Tg) was-7.6 ℃.

Example 12

Firstly, 125g of a mixed solvent of butyl acetate, xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:3:4) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 100g of styrene, 200g of n-butyl acrylate, 150g of 2-hydroxyethyl methacrylate, 8g of acrylic acid, 42g of ethylhexyl methacrylate, 55.5g of the organosilicon macromonomer prepared in example 10 and 48g of tert-butyl 2-ethyl hexanoate peroxide into a reaction kettle through a peristaltic pump, maintaining the reaction temperature at 120-140 ℃ in the dropwise adding process, and controlling the dropwise adding speed to ensure that the dropwise adding of the reaction mixture is finished within 2-4 h. After the dropwise addition, continuously preserving the heat for 2-4 h at 120-140 ℃, and terminating the reaction to obtain organosilicon modified acrylic resin with the solid content of 81.6%, the hydroxyl value of 116mg KOH/g, the organosilicon content of 10%, the B-type rotational viscosity of 7.4 Pa.s and the number average molecular weight of 2500 or so, and the acid value of 11.2mg KOH/g; the glass transition temperature (Tg) was-12 ℃.

The components of the high scratch resistance and high weathering single-component varnish compositions according to the invention, the preparation process and the specific use thereof are illustrated in the following examples 13 to 21, and the invention is further illustrated with reference to the following examples:

the highly scratch-resistant and highly weather-resistant one-component varnish compositions for automobile finishing and other related fields mentioned in examples 13 to 21 of the present invention were prepared by mixing and stirring them with a catalyst, an auxiliary and a solvent through a dispersing device according to the amounts of the various resin components set forth in tables 1 and 2.

In order to ensure the homogeneity of the quality and properties of the high scratch and weathering resistant one-component varnish compositions, the preparation process should be carried out by mixing the components with stirring at ambient temperature and pressure in the following specified addition sequence (taking the example of preparing a 1kg sample of the one-component varnish composition):

firstly, adding 0.5-10 parts of solvent and 1-20 parts of polymer with hyperbranched or dendritic structure into a dispersion kettle, and stirring at a stirring speed of 400-1000 revolutions per minute (r/min) for 10-60 minutes (min);

secondly, adding 5-50 parts of hydroxyl acrylic resin or hydroxyl methacrylic resin and 1-20 parts of organic silicon modified acrylic resin into a dispersion kettle, and stirring for 10-15 minutes under the same stirring state;

under the condition that the stirring speed is kept unchanged, sequentially adding 1-10 parts of an auxiliary agent, 5-30 parts of a rheological control agent and 10-70 parts of a crosslinking curing agent into a dispersion kettle, wherein the adding time of each component is 5-8 minutes apart from each other, and adding the next component after the previous component is fully stirred and mixed;

and fourthly, continuously keeping the stirring speed of 400-1000 r/m, finally adding 0.1-3 parts of acid catalyst and 0.5-32 parts of solvent into the dispersion kettle, stirring and dispersing for 30 minutes, and stopping stirring to obtain the single-component varnish composition.

Examples 13-16 Components and formulations for preparing the high scratch resistance and high weatherability one-component varnish compositions are shown in Table 1:

TABLE 1

Note:

^aexample 1 a polymer with hyperbranched or dendritic structure was prepared with a solids content of: 65 percent;

^bthe hydroxy (meth) acrylic resin prepared in example 7 had a solids content of: 80 percent;

^csilicone-modified acrylic resin prepared in example 11;

^dthe product of Nepetes resin (Suzhou) Co., Ltd under the brand name: setalux US138BB70, solids content: 70 percent;

^eproducts of basf (china) limited company under the brand numbers: larotact 150, solid content: 50 percent;

^fthe product of Nepetes resin (Suzhou) Co., Ltd under the brand name: setalux 61767, solids content: 60 percent;

^gthe product of King industries, the trade name is: nacure 2500;

^hproducts of German Bike chemical technology consultations (Shanghai) Co., Ltd and Basff (China) Co., Ltd are respectively provided with the following brands: BYK 315, BYK358N, Tinuvin 292, and Tinuvin 1130; the mass ratio of the substances is 1:1:1: 1.

ⁱButyl acetate, the mass ratio of the solvent used in the first step and the solvent used in the fourth step is 1: 2.

^jThe abrasion resistance of the cured coating film was measured by using a sandpaper of type P2400 on an abrasion tester, and the retention of 20 ° gloss of the coating film after abrasion for 15 cycles was examined.

The preparation method of comparative example 1 in Table 1 is the same as that of examples 13 to 16 except that the addition of the silicone-modified acrylic resin is not required in the second step.

Examples 17-21 Components and formulations for preparing the high scratch resistance and high weatherability one-component varnish compositions are shown in Table 2:

TABLE 2

Note:

^aexample 2 polymer with hyperbranched or dendritic structure prepared with a solids content of: 65 percent;

^bthe epoxy-modified hyperbranched polyester resin prepared in example 3 has a solid content of: 65 percent;

^cthe blocked isocyanate modified hyperbranched polyester resin prepared in example 5 has a solid content of: 65 percent;

^dthe hydroxy (meth) acrylic resin prepared in example 8 had a solids content of: 80 percent;

^ethe silicone-modified acrylic resin prepared in example 12 had a solid content of: 81.6 percent;

^fthe product of Nepetes corporation, the brand number is: setalux US138BB70, solids content: 70 percent;

^gzhanxin company products with brand numbers: cymel 303, solids content: 98 percent;

^hproducts of basf corporation under the brand names: larotact 150, solid content: 50 percent;

ⁱthe product of Nepetes corporation, the brand number is: setalux 61767, solids content: 60 percent;

^jthe product of King industries, the trade name is: nacure 2500;

^kproducts of German Bike and Basff, the brands are respectively: BYK 315, BYK358N, Tinuvin 292, and Tinuvin 1130; the mass ratio of the substances is 1:1:1: 1;

^lbutyl acetate, the mass ratio of the solvent used in the first step and the solvent used in the fourth step is 1: 2.

The high scratch-resistant and high weathering one-component varnish compositions prepared in examples 13 to 16 were subjected to a performance test, in which the composite coating films concerned (3C1B system) were prepared in the following manner. Firstly, selecting a cold rolling test board which is subjected to chemical pretreatment and covered with an electrophoretic coating, wherein the test board is prepared on an automobile OEM production line according to a standard processing technology; then, respectively spraying an aqueous dark gray middle coat (Nippon product) with the mark of AR800N2 and an aqueous black colored paint (Nippon product) with the mark of AR 3500731P according to a wet-on-wet process, and pre-drying the sprayed coating film for 8min at 85 ℃; then, spraying the varnish composition of the invention on the surface of the uncured colored paint again according to a wet-on-wet process in a construction state; finally, the composite coating, namely the multiple coating consisting of the water-based middle coating, the water-based colored paint and the varnish composition, is baked for 25min at 145 ℃ to form a composite coating consisting of the multiple coating; wherein the film thickness of each coating in the composite coating is respectively as follows: middle coating 20 +/-2 microns, colored paint 12 +/-1 microns and varnish 45 +/-5 microns.

As can be seen from the data in Table 1, the cup test and dry rub resistance data of the paint film are improved with the increase of the usage amount of the silicone modified acrylic resin compared with that of comparative example 1, which shows that the addition of the silicone modified acrylic resin to the varnish composition can improve the flexibility and rub resistance of the paint film. Further, the varnish compositions described in example 13 and example 14 had similar construction viscosities to those of the comparative example, and at this time, the construction solids of the varnish compositions described in example 13 and example 14 were both higher than those of the comparative example; on the other hand, the varnish compositions described in example 15 and example 16 have the same construction solids as the varnish composition in the comparative example, and the construction viscosity of the varnish compositions described in example 15 and example 16 is lower than that of the varnish composition in comparative example 1. From the above results, it was demonstrated that the addition of the silicone-modified acrylic resin to the varnish composition can contribute to the reduction of the construction viscosity of the varnish composition and the improvement of the construction solid content.

Example 22

Firstly, 125g of a mixed solvent of xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:1) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 50g of styrene, 225g of n-butyl acrylate, 175g of 2-hydroxyethyl methacrylate, 5g of acrylic acid, 45g of methyl methacrylate, 26.3g of the organosilicon macromonomer prepared in example 1 and 38g of tert-butyl peroxy-2-ethylhexanoate into a reaction kettle by a peristaltic pump, maintaining the reaction temperature at 130-140 ℃ in the dropwise adding process, and controlling the dropwise adding speed to ensure that the dropwise adding of the reaction mixture is completed within 2-4 h. After the dropwise addition is finished, continuously preserving the heat for 2-4 h at 130-140 ℃, and terminating the reaction to obtain organic silicon modified acrylic resin with the solid content of 80.8%, the hydroxyl value of 143mg KOH/g, the organic silicon content of 5%, the B-type rotational viscosity of 25Pa s and the number average molecular weight of 3000, and the acid value of 7.4 KOH/g; the glass transition temperature (Tg) was-7.6 ℃.

Example 23

Firstly, 125g of a mixed solvent of butyl acetate, xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:3:4) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 100g of styrene, 200g of n-butyl acrylate, 150g of 2-hydroxyethyl methacrylate, 8g of acrylic acid, 42g of ethylhexyl methacrylate, 55.5g of the organosilicon macromonomer prepared in example 2 and 48g of tert-butyl peroxy-2-ethylhexanoate into a reaction kettle by a peristaltic pump, maintaining the reaction temperature at 120-140 ℃ in the dropwise adding process, and controlling the dropwise adding speed to ensure that the dropwise adding of the reaction mixture is finished within 2-4 h. After the dropwise addition, continuously preserving the heat for 2-4 h at 120-140 ℃, and terminating the reaction to obtain organosilicon modified acrylic resin with the solid content of 81.6%, the hydroxyl value of 116mg KOH/g, the organosilicon content of 10%, the B-type rotational viscosity of 7.4 Pa.s and the number average molecular weight of 2500 or so, and the acid value of 11.2mg KOH/g; the glass transition temperature (Tg) was-12 ℃.

Example 24

Firstly, 156g of a mixed solvent of butyl acetate and xylene (mass ratio of 7:2) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, a reaction mixture consisting of 80g of styrene, 220g of n-butyl acrylate, 180g of 2-hydroxyethyl methacrylate, 2g of acrylic acid, 18g of dodecyl methacrylate, 43.5g of the organosilicon macromonomer prepared in example 3 and 53.4g of tert-butyl peroxy-2-ethylhexanoate is dripped into a reaction kettle through a peristaltic pump, the reaction temperature is maintained between 120 and 130 ℃ during the dripping process, and the dripping speed is controlled to ensure that the reaction mixture is dripped within 2 to 4 hours. After the dropwise addition, continuously preserving the heat for 2-4 h at 120-130 ℃, and terminating the reaction to obtain organosilicon modified acrylic resin with the solid content of 77.7%, the hydroxyl value of 143mg KOH/g, the organosilicon content of 8%, the B-type rotational viscosity of 8.7 Pa.s and the number average molecular weight of 2200 or so, and the acid value of 2.9mg KOH/g; the glass transition temperature (Tg) was-9.5 ℃.

Example 25

Firstly, 125g of a mixed solvent of xylene and propylene glycol monomethyl ether acetate (mass ratio of 1:1) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, a reaction mixture consisting of 53g of styrene, 220g of n-butyl acrylate, 175g of 2-hydroxyethyl methacrylate, 7g of acrylic acid, 45g of methyl methacrylate, 26.3g of the organosilicon macromonomer prepared in example 4 and 35g of tert-amyl peroxy-2-ethylhexanoate is dripped into a reaction kettle through a peristaltic pump, the reaction temperature is maintained between 130 and 140 ℃ during the dripping process, the dripping speed is controlled, and the reaction mixture is ensured to be dripped within 2 to 4 hours. After the dropwise addition, continuously preserving the heat for 2-4 h at 130-140 ℃, and terminating the reaction to obtain organic silicon modified acrylic resin with the solid content of 80.8%, the hydroxyl value of 143mg KOH/g, the organic silicon content of 5%, the B-type rotational viscosity of 27.4 Pa.s and the number average molecular weight of 3500, and the acid value of 10.4mg KOH/g; the glass transition temperature (Tg) was-7.1 ℃.

Example 26

Firstly, 125g of a mixed solvent of xylene and propylene glycol monomethyl ether acetate (mass ratio of 2:1) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 50g of styrene, 175g of n-butyl acrylate, 175g of 2-hydroxyethyl methacrylate, 5g of acrylic acid, 95g of methyl methacrylate, 88g of the organosilicon macromonomer prepared in example 1 and 61g of tert-amyl peroxybenzoate into a reaction kettle by a peristaltic pump, maintaining the reaction temperature between 130 and 140 ℃ in the dropwise adding process, and controlling the dropwise adding rate to ensure that the dropwise adding of the reaction mixture is completed within 2 to 4 hours. After the dropwise addition is finished, continuously preserving the heat for 2-4 h at 130-140 ℃, and terminating the reaction to obtain organosilicon modified acrylic resin with the solid content of 82.5%, the hydroxyl value of 128mg KOH/g, the organosilicon content of 15%, the B-type rotational viscosity of 5.4 Pa.s and the number average molecular weight of 2000 or so, and the acid value of 6.6mg KOH/g; the glass transition temperature (Tg) was-16.2 ℃.

Example 27

Firstly, 100g of a mixed solvent of butyl acetate and S-100# solvent oil (the mass ratio is 1:4) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, dropwise adding a reaction mixture consisting of 30g of styrene, 70g of n-butyl acrylate, 70g of tert-butyl methacrylate, 50g of vinyl versatate, 100g of 2-hydroxypropyl methacrylate, 6g of acrylic acid, 74g of isobornyl methacrylate, 20g of the organosilicon macromonomer prepared in example 1 and 14g of di-tert-butyl peroxide into a reaction kettle by a peristaltic pump, maintaining the reaction temperature at 130-140 ℃ in the dropwise adding process, controlling the dropwise adding rate, and ensuring that the dropwise adding of the reaction mixture is completed within 2-4 h. After the dropwise addition, continuously keeping the temperature at 130-140 ℃ for 2-4 h, and terminating the reaction to obtain the organic silicon modified acrylic resin with the solid content of 80.8%, the hydroxyl value of 92mg KOH/g, the organic silicon content of 4.7%, the B-type rotational viscosity of 7.7 Pa.s and the number average molecular weight of about 2200, the acid value of 11mgKOH/g and the Tg of-3.1 ℃.

Example 28

Firstly, 200g of a mixed solvent of butyl acetate, xylene and amyl acetate (mass ratio of 1:4:5) is added into a 1L reaction kettle provided with a stirrer, a thermometer, a nitrogen guide pipe and a reflux condenser, and the temperature of a reaction system is raised to 130-140 ℃. After the reaction temperature is stable, a reaction mixture consisting of 100g of styrene, 150g of n-butyl acrylate, 100g of ethylhexyl methacrylate, 100g of 2-hydroxyethyl methacrylate, 75g of 2-hydroxypropyl methacrylate, 10g of acrylic acid, 10g of methacrylic acid, 100g of dodecyl acrylate, 55g of isobornyl methacrylate, 100g of di-n-butyl maleate, 50g of the organosilicon macromonomer prepared in example 2 and 33g of di-tert-butyl peroxide is dripped into a reaction kettle through a peristaltic pump, the reaction temperature is maintained between 130 and 140 ℃ in the dripping process, the dripping rate is controlled, and the reaction mixture is ensured to be dripped within 2 to 4 hours. After the dropwise addition, continuously keeping the temperature at 130-140 ℃ for 2-4 h, and terminating the reaction to obtain the organic silicon modified acrylic resin with the solid content of 80.9%, the hydroxyl value of 88mg KOH/g, the organic silicon content of 2.4%, the B-type rotational viscosity of 3.3 Pa.s and the number average molecular weight of 1800 or so, the acid value of 17.5mg KOH/g and the Tg of-2.7 ℃.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the invention and are not to be construed as limiting the embodiments of the present invention, and that various other changes and modifications may be made by those skilled in the art based on the above description. All documents mentioned in this application are incorporated by reference into this application as if each were individually incorporated by reference.

Claims

1. A one-component varnish composition, characterized in that: the method comprises the following steps:

at least one polymer having a hyperbranched or dendritic structure;

at least one hydroxy acrylic resin or hydroxy methacrylic resin;

at least one silicone-modified acrylic resin;

at least one crosslinking curing agent;

at least one acid catalyst;

at least one rheology control agent;

at least one auxiliary agent; and

at least one solvent;

the one-component varnish composition is a high scratch-resistant and high weather-resistant one-component varnish composition;

wherein:

in formula I:

R₁selected from aliphatic, alicyclic and aromatic alkyl, alkoxy, acyloxy and hydroxyalkyl containing 1-20 carbon atoms;

R₂、R₃、R₄、R₅each independently selected from hydrogen atoms, aliphatic, alicyclic and aromatic alkyl groups containing 1 to 20 carbon atoms and hydroxyalkyl groups;

R₆is selected from one of the formulas II:

R₇is selected from the group consisting of those of formula IIIOne of (1):

m>0，n>0，o>0，p>0，q>0，x>0，y>0；

the organic silicon modified acrylic resin comprises organic silicon macromonomer,

3) Modifying cyclotrisiloxane with trimethylsiloxy alkyl group

5) adding an organic silicon macromonomer F with a side chain having a hydroxyl protecting group and a methacrylic group at a single end into an alcohol solvent, and reacting by taking weak acid as a catalyst at the reaction temperature of: 65-100 ℃, and the reaction time is as follows: and (4) distilling under reduced pressure for 4-12h to remove low-boiling-point substances to obtain the organosilicon macromonomer G with the side chain having the hydroxyl group and the single end having the methacrylic group.

2. The one-component varnish composition according to claim 1, characterized in that: the paint comprises the following components in parts by weight:

3. the one-component varnish composition according to claim 1 or 2, characterized in that: the polymer with the hyperbranched or dendritic structure is a high molecular polyester with the hyperbranched or dendritic structure, each high molecular polyester contains 8-80 hydroxyl groups on average, the hydroxyl value is between 150-600 mgKOH/g, and the glass transition temperature is between-25 ℃ and +30 ℃;

hydroxyl in the polymer with the hyperbranched or dendritic structure is modified and substituted by epoxy groups and closed aliphatic isocyanate groups, so that epoxy modified hyperbranched polyester resin and closed isocyanate modified hyperbranched polyester resin are obtained; and the number of the modified and substituted functional groups, namely the number of the substituted hydroxyl groups, accounts for 1 to 50 percent of the number of the hydroxyl groups in the original hyperbranched or dendritic polymer.

4. The one-component varnish composition according to claim 3, characterized in that: the epoxy modified hyperbranched polyester resin is prepared by taking hyperbranched hydroxyl polyester, anhydride and epoxy resin as raw materials and has the following structural formula:

being a backbone of hyperbranched hydroxy polyester, R₁The alkyl group remained after the acid anhydride group is removed from the acid anhydride molecule, wherein the acid anhydride is at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, phthalic anhydride, maleic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, dodecenyl succinic anhydride and trimellitic anhydride; r₂The epoxy resin is an alkyl group remained after epoxy groups are removed from epoxy resin molecules, wherein the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1, 2-propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1, 4-butylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, phthalic acid diglycidyl ester, isophthalic acid diglycidyl ester, terephthalic acid diglycidyl ester and tetrahydrophthalic acid diglycidyl ester.

5. The one-component varnish composition according to claim 3, characterized in that: the blocked isocyanate modified hyperbranched polyester resin is prepared by taking hyperbranched hydroxyl polyester, isocyanate and a blocking agent as raw materials, and has the following structural formula:

in the formulaX and y are positive integers, 2 ≦ x + y ≦ total number of functional groups of the hyperbranched hydroxyl polyester;

being a backbone of hyperbranched hydroxy polyester, R₃The isocyanate is an alkyl group remained after removing isocyanate groups in isocyanate molecules, wherein the isocyanate is at least one of toluene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane isocyanate, trimethyl hexamethylene diisocyanate and hydrogenated toluene diisocyanate; r₄Is an alkyl group remained after removing active hydrogen in a sealant molecule, wherein: the sealant is at least one of methanol, ethanol, propanol, butanol, hexanol, octanol, benzyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether, methyl ethyl ketoxime, acetone oxime, cyclohexanone oxime, diisopropyl amine, 3, 5-dimethylpyrazole, N-tert-butylbenzylamine, caprolactam, dimethyl malonate and diethyl malonate.

6. The one-component varnish composition according to claim 1 or 2, characterized in that: the hydroxyl value of the hydroxyl acrylic resin or the hydroxyl methacrylic resin is between 110 and 250mg KOH/g, the glass transition temperature is between-10 ℃ and +35 ℃, the number average molecular weight is between 2000 and 4000, and the solid content is more than or equal to 80 percent.

7. The one-component varnish composition according to claim 1 or 2, characterized in that: the hydroxyl value of the organic silicon modified acrylic resin is between 50 and 250 mgKOH/g; the acid value is between 0 and 20mg KOH/g; the glass transition temperature is between-30 ℃ and +50 ℃; the number average molecular weight is 500-20000; the solid content is between 70 and 100 percent, and the B-type rotational viscosity is between 0.5 and 200 Pa.s.

8. The one-component varnish composition according to claim 1 or 2, characterized in that: the organic silicon modified acrylic resin comprises the following components in parts by weight:

9. the one-component varnish composition according to claim 8, wherein: the solvent is selected from at least one of aliphatic ester, monohydric alcohol, ketone, dihydric alcohol ether, dihydric alcohol ester and aromatic hydrocarbon solvent;

the derivative of the acrylate and/or methacrylate monomer is selected from at least one of alkyl acrylate, alkyl methacrylate, cycloalkyl acrylate and cycloalkyl methacrylate;

the derivative of the acrylate and/or methacrylate monomer containing hydroxyl is selected from at least one of hydroxyalkyl acrylate and hydroxyalkyl methacrylate;

the initiator is selected from at least one of azo initiators or peroxy initiators.

10. The one-component varnish composition according to claim 9, characterized in that: the solvent is at least one of toluene, xylene, S-100# solvent oil, trimethylbenzene solvent oil, S-150# solvent oil, durene solvent oil, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, ethylene glycol butyl ether acetate, amyl acetate, ethylene glycol ethyl ether propionate, ethylene glycol butyl ether, ethylene glycol, n-propanol, isopropanol, n-butanol and propylene glycol methyl ether acetate;

the monomer containing the carbon-carbon double bond and capable of undergoing copolymerization reaction is at least one of styrene, methyl propylene, allyl alcohol, ethylene versatate, monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, mono-isopropyl maleate, mono-n-butyl maleate, mono-sec-butyl maleate, mono-tert-butyl maleate, monopentyl maleate, monohexyl maleate, mono-ethylhexyl maleate, dimethyl maleate, diethyl maleate, di-n-propyl maleate, di-isopropyl maleate, di-n-butyl maleate, di-sec-butyl maleate, di-tert-butyl maleate, dipentyl maleate, dihexyl maleate and di-ethylhexyl maleate;

the derivative of the acrylate and/or methacrylate monomer is methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, pentyl acrylate, pentyl methacrylate, hexyl acrylate, hexyl methacrylate, ethylhexyl acrylate, ethylhexyl methacrylate, 3, 5-trimethylhexyl acrylate, 3, 5-trimethylhexyl methacrylate, octadecyl acrylate, octadecyl methacrylate, dodecyl acrylate, dodecyl methacrylate, cyclopentyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, at least one of cyclopentyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, glycidyl acrylate and glycidyl methacrylate;

the derivative of the acrylic ester and/or methacrylic ester monomer containing hydroxyl is at least one of 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, a condensation product of acrylic acid and glycidyl versatate, and a condensation product of methacrylic acid and glycidyl versatate;

the derivative of acrylic acid and/or methacrylic acid containing carboxyl is selected from acrylic acid and/or methacrylic acid;

the initiator is at least one of azobisisobutyronitrile, azobisisoheptonitrile, benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, 1-bis (tert-amylperoxy) cyclane, 1-bis (tert-amylperoxy) -3,3, 5-trimethylcyclohexane, tert-butyl peroxybenzoate, tert-amyl peroxyacetate, tert-butyl peroxy-3, 5-trimethylhexanoate, ethyl 3, 3-bis (tert-butylperoxy) butyrate, ethyl 3, 3-bis (tert-amylperoxy) butyrate, dicumyl peroxide, tert-amyl hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide and di-tert-amyl peroxide.

11. The one-component varnish composition according to claim 1 or 2, characterized in that: the molar ratio of the unsaturated monohydric alcohol A to the hexamethyldisilazane is 2 (1-2);

12. the one-component varnish composition according to claim 1 or 2, characterized in that: the catalyst is chloroplatinic acid;

the trimethyl siloxy unsaturated compound B and trimethyl cyclotrisiloxane

The molar ratio of (a) to (b) is 3: 1-6: 1;

13. Single stack according to claim 1 or 2A paint separating composition is characterized in that: the mass ratio of the nonpolar organic solvent to the polar solvent is 1: 1-1: 5, and the total mass of the nonpolar organic solvent and the polar solvent is equal to that of the trimethylsiloxy alkyl modified cyclotrisiloxane

Hexamethylcyclotrisiloxane D₃The total mass ratio of the alkyl lithium is 1: 4-4: 1;

the molar ratio of the alkyl lithium initiator to the dimethyl hydrochlorosilane is 1: 1-1: 1.2.

14. The one-component varnish composition according to claim 1 or 2, characterized in that: the nonpolar organic solvent is selected from at least one of aliphatic hydrocarbon solvent, alicyclic hydrocarbon solvent and aromatic hydrocarbon solvent;

the polar solvent is at least one selected from aliphatic ketones, alicyclic ketones, aromatic ketones, amides, sulfoxides, nitriles and heterocyclic solvents.

15. The one-component varnish composition of claim 14, wherein: the nonpolar organic solvent is at least one of isopentane, n-pentane, petroleum ether, n-hexane, cyclohexane, isooctane, cyclopentane, trimethylpentane, cyclopentane, heptane, toluene, benzene and xylene;

the alkyl lithium initiator is selected from at least one of n-butyl lithium, sec-butyl lithium, tert-butyl lithium and trimethylsiloxy lithium;

the polar solvent is at least one of tetrahydrofuran, formamide, acetonitrile, N-dimethylformamide, hexamethylphosphoramide, butanone, dimethyl sulfoxide, acetone, 1, 4-dioxane and pyridine.

16. The one-component varnish composition according to claim 1 or 2, characterized in that: the mass of the polymerization inhibitor accounts for 0.1-5% of that of the allyl methacrylate;

the mass of the catalyst accounts for 0.05-1% of that of the organic silicon macromolecule E with a hydroxyl protecting group at a side chain and a hydrosilyl group at a single end;

the mol ratio of allyl methacrylate to the silicon-hydrogen groups contained in the organic silicon macromolecule E with the side chain having the hydroxyl protecting group and the single end having the silicon-hydrogen groups is 1: 1-2: 1;

the polymerization inhibitor is selected from phenolic polymerization inhibitors and quinone polymerization inhibitors.

17. The one-component varnish composition of claim 16, wherein: the polymerization inhibitor is at least one of hydroquinone, p-benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butyl hydroquinone and 2, 5-di-tert-butyl hydroquinone;

the catalyst is chloroplatinic acid.

18. The one-component varnish composition according to claim 1 or 2, characterized in that: the mass ratio of the organic silicon macromonomer F with the side chain provided with the hydroxyl protecting group and the single end provided with the methacrylic group to the alcohol solvent is 1: 1-1: 4;

the mass of the weak acid accounts for 0.5-5% of that of the organosilicon macromonomer F with a hydroxyl protecting group on a side chain and a methacrylic acid group on a single end;

the alcohol solvent is selected from at least one of methanol, ethanol, n-propanol and isopropanol;

19. The one-component varnish composition according to claim 1, characterized in that: the crosslinking curing agent is 10-40 parts of alkylated melamine formaldehyde resin;

20. The one-component varnish composition according to claim 1 or 2, characterized in that: the acid catalyst is a sulfonic acid type catalyst containing free and blocked sulfonic acid groups;

the rheology control agent is selected from compounds containing urea bonds, polymers and related derivatives thereof, and/or high molecular fine particles with a cross-linked structure, and/or surface-treated fine silica particles;

the auxiliary agent is at least one selected from a leveling control agent, an ultraviolet absorber and a hindered amine light stabilizer.

21. The one-component varnish composition of claim 20, wherein: the auxiliary agent further comprises an antioxidant and an anti-settling agent.

22. The one-component varnish composition according to claim 1 or 2, characterized in that: the solvent is at least one of aliphatic ester, ketone, dihydric alcohol ether, dihydric alcohol ester and aromatic hydrocarbon solvent.

23. The one-component varnish composition of claim 22, wherein: the solvent is at least one of toluene, xylene, S-100# solvent oil, trimethylbenzene solvent oil, S-150# solvent oil, durene solvent oil, acetone, butanone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, ethylene glycol butyl ether acetate, amyl acetate, ethylene glycol ethyl ether propionate, ethylene glycol butyl ether and ethylene glycol.

24. A process for preparing a one-component varnish composition according to any one of claims 1 to 23, wherein: the method comprises the following steps:

25. The method of preparing a one-component varnish composition according to claim 24, wherein: the stirring and mixing are uniform, namely the stirring speed is 400-1000 revolutions per minute, and the stirring time is 10-60 min;

26. Use of a one-component varnish composition according to any one of claims 1 to 23 as an overprint varnish, characterized in that: the method comprises the following steps:

the single-component varnish composition is applied to a pre-coated substrate and cured at a temperature of 80-180 ℃ to form a varnish coating.

27. Use of a one-component varnish composition according to any one of claims 1 to 23, for the preparation of a multi-coat finishing system, characterized in that: the multi-coat finishing system comprises at least one color coat and at least one clear coat, wherein the clear coat is the outermost coat of the multi-coat finishing system and is prepared from the single-component clear coat composition; wherein the one-component varnish composition is a high scratch-resistant and high weather-resistant one-component varnish composition.

28. Use of the one-component varnish composition according to claim 27, for the preparation of a multi-coat finishing system, characterized in that: the method comprises the following steps:

alternatively, the first and second electrodes may be,

applying two coats of pigmented paint to a substrate without a primer and a basecoat, then spraying the one-component clear coat composition over a second coat of pigmented paint and simultaneously curing the three coats to obtain the multi-coat finish system, which can be used in a compact spray process system;

alternatively, the first and second electrodes may be,

applying a basecoat or midcoat paint to a substrate and curing it, then applying a monocolor paint to said substrate with the basecoat or midcoat already cured, then applying a pearlescent paint to the uncured monocolor paint coat surface, then applying said monocomponent clearcoat composition to the uncured pearlescent paint surface, and finally curing the three part coats simultaneously to obtain said multi-coat finish system, which can be used in a four coat two bake system;

alternatively, the first and second electrodes may be,

the multi-coat finishing system is obtained by applying a base coat or a mid-coat to a substrate, applying a single-component lacquer to the surface of the uncured base coat or mid-coat, applying a pearlescent lacquer to the surface of the uncured mono-component lacquer coat, applying the single-component clear coat composition to the surface of the uncured pearlescent lacquer coat, and simultaneously curing the four part-coats to obtain the multi-coat finishing system, which can be used in a four-coat one-bake system.

29. Use of the one-component varnish composition according to claim 28, for the preparation of a multi-coat finishing system, characterized in that: the priming paint and/or the colored paint used in the three-coating two-baking, three-coating one-baking or integrated spraying process, the compact spraying process, the four-coating two-baking and four-coating one-baking process system are water-based paint or solvent-based paint, and the solid content of the priming paint and/or the colored paint in construction is 25-55 percent; the colored paint is at least one of a single-color paint, a metal paint or a flashing paint, and the thickness of the cured film is 5-40 μm;

the primer or the middle paint is a water-based or solvent-based primer or middle paint; the thickness of the cured film is 10-50 μm;

the dry film thickness of the multi-coating finishing system is 10-80 mu m; the curing temperature is 100-180 ℃; the curing time is 10-40 min.