CN110951057A

CN110951057A - Preparation method of alkyd resin and prepared resin, preparation method of acrylic acid modified alkyd resin and prepared resin

Info

Publication number: CN110951057A
Application number: CN201811123729.2A
Authority: CN
Inventors: 焦方军; 文振广; 黄旭
Original assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Beijing Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Beijing Co Ltd
Priority date: 2018-09-26
Filing date: 2018-09-26
Publication date: 2020-04-03

Abstract

The invention provides a preparation method of alkyd resin and the prepared resin, a preparation method of acrylic acid modified alkyd resin and the prepared resin, wherein the preparation method of alkyd resin improves the structure of alkyd resin by adding unsaturated carboxylic acid and/or unsaturated anhydride step by step; according to the preparation method of the acrylic acid modified alkyd resin, the unsaturated monomer is fed step by step, the feeding time is controlled, the unsaturated monomer is uniformly grafted on the alkyd resin, and the molecular weight distribution is narrower. The acrylic acid modified alkyd resin prepared by the preparation method is applied to water-based paint, so that a paint film has the advantages of high drying speed, high glossiness, good fullness, low VOC (volatile organic compounds) emission, excellent comprehensive performance and the like.

Description

Preparation method of alkyd resin and prepared resin, preparation method of acrylic acid modified alkyd resin and prepared resin

Technical Field

The invention relates to a preparation method of alkyd resin and a preparation method of acrylic acid modified alkyd resin. The resin prepared by the preparation method of the acrylic acid modified alkyd resin is applied to the field of coatings, in particular to the field of water-based coatings.

Background

With the continuous progress of the scientific and technological level and the continuous enhancement of the environmental protection consciousness of people, the water-based paint gradually replaces the solvent-based paint with high pollution and high waste due to the outstanding environmental protection. However, water-based coatings still have problems such as slow drying speed of paint films, low gloss, poor fullness, high VOC emissions, high overall cost, and the like, as compared with solvent-based coatings. The main factor influencing the paint film performance is resin used in a paint formula, and the resin commonly used in the existing water-based paint is acrylic resin, epoxy resin, alkyd resin and the like, wherein the alkyd resin is widely applied to the water-based paint by virtue of the advantages of good comprehensive performance, cheap and easily available raw materials and the like. However, the various resins disclosed in the prior art, including alkyd resins, still cannot simultaneously solve the problems of low drying speed, low gloss, poor fullness, high VOC emission, high overall cost, and the like in aqueous coatings.

The patent CN201310521476.5 discloses a waterborne acrylic acid modified alkyd resin and a preparation method thereof, in the technical scheme, the acrylic acid modified alkyd resin has high acrylic acid modification ratio and high solid content, so that the viscosity of a reaction system is difficult to control, and the gel is very easy to gel in the synthesis process; however, if the solids content is reduced, the VOC of the coatings prepared with the corresponding resins is higher.

Patent CN200810155329.X discloses a water-based short-oil alkyd resin and a preparation method thereof, and in the technical scheme, the synthesized water-based alkyd resin is extremely easy to hydrolyze in the presence of carboxyl due to a large amount of ester bonds, and has poor storage stability.

Patent CN201210157799.6 discloses a method for synthesizing styrene and acrylate modified quick-drying alkyd resin, in the technical scheme, the modification process is based on long oil alkyd resin, styrene and acrylate monomer are adopted for modification and copolymerization, and the modified and grafted position is on the conjugated double bond of linoleic acid, however, because the glass transition temperature of butyl methacrylate adopted in the technical scheme is low and participates in copolymerization in a large amount, the obtained paint film of the resin is soft, the surface drying speed of the paint film is slow, and the performance still can not meet the requirements.

Therefore, it is desirable to provide a method for preparing a coating resin with high drying speed, high gloss, good fullness, low VOC emission, and excellent overall properties.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a preparation method of alkyd resin, the prepared alkyd resin, a preparation method of acrylic acid modified alkyd resin and the prepared acrylic acid modified alkyd resin.

The technical scheme of the invention is as follows.

A preparation method of alkyd resin comprises a reaction stage 1 and a reaction stage 2, wherein the reaction stage 1 is to mix reaction raw materials to react in the presence of an A1 catalyst, and the reaction raw materials comprise an A2 compound, an A3 compound and an A4 compound, wherein the A2 compound is vegetable oleic acid and/or synthetic fatty acid with 8 to 20 carbon atoms, the A3 compound is a hydroxyl compound, and the A4 compound is saturated carboxylic acid and/or saturated anhydride;

and in the reaction stage 2, after the reaction stage 1 is finished, the compound A5 is added into the reaction system step by step for reaction, wherein the compound A5 is unsaturated carboxylic acid and/or unsaturated anhydride.

The a1 catalyst may be a catalyst having a catalytic action for esterification reaction, which is commonly used in the art, and examples thereof include, but are not limited to, a titanate-based catalyst, an organotin-based catalyst, a phosphite-based catalyst, and the like, and such catalysts may be used alone or in combination. Preferably, the a1 catalyst is selected from one or more of tetrabutyl titanate, butyltin dilaurate, monobutyltin oxide, dibutyltin diacetate, monobutyltin trichloride, and triphenyl phosphite.

The a2 compound is vegetable oleic acid and/or synthetic fatty acid having 8 to 20 carbon atoms, examples of which include, but are not limited to, soya oleic acid, linoleic acid, linolenic acid, eleostearic acid, ricinoleic acid, tall oil acid, cottonseed oil acid, etc., and examples of the synthetic fatty acid having 8 to 20 carbon atoms include, but are not limited to, lauric acid, stearic acid, palmitic acid, etc., which may be used alone or in combination.

Preferably, the a2 compound is selected from one or more of the group consisting of soya oil acid, linoleic acid, linolenic acid, eleostearic acid, ricinoleic acid, tall oil acid, rosin, lauric acid.

The A3 compound is a hydroxyl compound, and the functionality of the compound is 1-4, preferably 2-4. Examples include, but are not limited to, methanol, ethanol, propanol, butanol, pentanol, ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 2-butanediol, 1, 3-butanediol, 1, 4-butanediol, 2-methyl-1, 3-propanediol, neopentyl glycol, 1, 5-pentanediol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 2-ethyl-2-butyl-1, 3-propanediol, 2, 4-trimethyl-1, 3-pentanediol, 2, 4-diethyl-1, 5-pentanediol, 1, 8-nonanediol, 3-methyl-1, 7-heptanediol, 4-methyl-1, 8-octanediol, 1, 2-propanediol, 1, 3-propanediol, 3-methyl-1, 3-propanediol, 2, 3-butanediol, 2-methyl-1, 5-pentanediol, 4-propyl-1, 8-octanediol, 1, 9-nonanediol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1, 4-cyclohexanedimethanol, 1, 3-cyclohexanedimethanol, 1, 2-cyclohexanedimethanol, glycerol, trimethylolpropane, trimethylolethane, pentaerythritol and the like, and these hydroxyl compounds may be used alone or in combination.

In a preferred embodiment of the present invention, the a3 compound is selected from one or more of ethylene glycol, diethylene glycol, neopentyl glycol, glycerol, trimethylolpropane, trimethylolethane, and pentaerythritol.

The A4 compound is a saturated carboxylic acid and/or a saturated acid anhydride, wherein the functionality of the carboxylic acid is 1-3. Examples of the a4 compound include, but are not limited to, benzoic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, isophthalic acid, terephthalic acid, trimellitic acid, 1, 4-cyclohexanedicarboxylic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, and the like, and such small molecular carboxyl compounds may be used alone or in combination.

In a preferred embodiment of the present invention, the a4 compound is selected from one or more of benzoic acid, adipic acid, sebacic acid, isophthalic acid, terephthalic acid, trimellitic acid, 1, 4-cyclohexanedicarboxylic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and trimellitic anhydride.

The reaction temperature of the reaction stage 1 is 150-280 ℃, and preferably 170-260 ℃.

In the reaction stage 1, after each reaction raw material is added into the reactor, part of the materials generally react at a relatively low temperature, for example, 150 to 190 ℃, preferably 170 to 190 ℃, in which the reaction is mainly an esterification reaction between the a2 compound and the A3 compound, so that the reactants are primarily polymerized, and in addition, at the initial stage of the reaction, the reaction system generates a large amount of water, and the low temperature is favorable for controlling the water yield and facilitating water removal; after the reaction system is subjected to the low-temperature preliminary polymerization, the temperature can be raised to a higher range, for example, 190-280 ℃, preferably 190-260 ℃ for reaction, and in the temperature range, the reactivity of the A4 compound is improved, and more of the A4 compound participates in the esterification reaction for reaction. Through the steps, molecules formed by reactants after the reaction stage 1 have certain regularity in structure, and adverse factors such as violent reaction process after direct heating to high temperature, disordered molecular structure of the reactants caused by simultaneous reaction of all the reactants and the like are avoided. The specific operation steps not described in the reaction stage 1 can be carried out by referring to the methods commonly used in the art, and do not affect the implementation of the invention.

A preferred embodiment of the invention is illustrated: the reaction step of the reaction stage 1 is that under the atmosphere of inert gas, the A1 catalyst, the A2 compound, the A3 compound and the A4 compound are mixed and mixed uniformly at normal temperature, the temperature is increased to 150-280 ℃, preferably 170-260 ℃, the reaction is carried out, and when the reaction system is clear and transparent, the reaction stage 1 is finished.

In any preparation method described in the present invention, the reaction temperature of the reaction system is achieved by heating, and the reaction temperature of the reaction system during the reaction is preferably within the range defined in the present invention; in practice, dynamic adjustment of the temperature and the holding time of the reaction system within the temperature range defined in the present invention, for example, for the purpose of controlling the color, acid value, viscosity, reaction speed, etc., of the reaction system, is well known to those skilled in the art, and does not affect the practice of the present invention.

The a5 compound is an unsaturated carboxylic acid and/or unsaturated anhydride, and examples thereof include, but are not limited to, maleic anhydride, dehydrated castor oil, tung oil, rosin, fumaric acid, eleostearic acid, and the like, and such compounds may be used alone or in combination.

In a preferred embodiment of the present invention, the a5 compound is selected from one or more of maleic anhydride, dehydrated castor oil, tung oil, fumaric acid and eleostearic acid.

The reaction temperature of the reaction stage 2 is 150-240 ℃, and preferably 160-225 ℃.

The specific operation steps not described in the reaction stage 2 can be carried out by referring to the methods commonly used in the field, and do not influence the implementation of the invention.

In a preferred embodiment of the present invention, the reaction step in the reaction stage 2 is to add the compound a5 to the reaction system in the reaction stage 2-1 and the reaction stage 2-2, respectively, to perform a reaction.

It should be noted that, the step of adding a reaction system to the a5 compound in the reaction stage 2-1 and the reaction stage 2-2 respectively to perform a reaction means that a part of the total mass of the a5 compound is added to the reaction system to perform a reaction, that is, the reaction stage 2-1, and after the first part of the a5 compound is substantially completely reacted and the reaction stage 2-1 is finished, the remaining a5 compound is added to perform a reaction, that is, the reaction stage 2-2. The A5 compound is subjected to two-step feeding reaction, molecules with unsaturated double bonds can be respectively connected to the middle and two ends of a polyester main chain in an alkyd resin macromolecule, but not all molecules are concentrated at a single position of the polyester main chain, the unsaturated double bonds provided by the A5 compound can be used as a grafting base point for the free radical polymerization modification of acrylate and vinyl monomers in the next step, so that grafted long-chain molecules are more uniformly distributed on the original alkyd resin main chain, the molecular weight distribution range is narrower, and the application performance is more outstanding.

Preferably, the reaction temperature of the reaction stage 2-1 is 180-240 ℃, preferably 210-225 ℃, and the reaction temperature of the reaction stage 2-2 is 150-190 ℃, preferably 160-175 ℃.

Preferably, the reaction time of the reaction stage 2-1 is 1-3 hours, preferably 1-2 hours, and the reaction time of the reaction stage 2-2 is 0.5-3 hours, preferably 0.5-1.5 hours.

Preferably, the reaction process of the reaction stage 2 can be added with an organic solvent to carry out condensation reflux and dehydration. The organic solvent may be an organic solvent commonly used in the art, and examples thereof include, but are not limited to, xylene, n-butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, and the like, and such organic solvents may be used alone or in combination.

It should be noted that, in the preparation method of the alkyd resin, the step of "adding an organic solvent to perform condensation reflux and dehydration" is to remove water generated by the reaction system, and the step is added in the reaction stage 2, so that on one hand, the operation steps can be simplified, the process cost can be saved, and on the other hand, the water removal effect on the reaction system can be enhanced. Other steps which serve the same purpose can be equivalently replaced, for example, in the alkyd resin preparation method, an organic solvent is added into a reaction system, and the reaction process is carried out under an inert gas atmosphere and is vacuumized; for another example, in the preparation method of the alkyd resin, no organic solvent is added, and the reaction process is placed in an inert gas atmosphere and vacuumized; for another example, in the preparation method of the alkyd resin, no organic solvent is added, and the reaction process is placed in an inert gas atmosphere without vacuum pumping and the like.

Preferably, the content of the A5 compound added in the reaction stage 2-1 is 20-60%, preferably 30-50%, more preferably 30-40% of the total mass of the A5 compound.

And obtaining an alkyd resin product after the reaction stage 2 is finished.

After the end of the reaction stage 2, a diluent may or may not be added as required. The method for adding the diluent can adopt a method commonly used in the field, for example, after the reaction stage 2 is finished, the reaction system is cooled to below 150 ℃, the diluent is added, and the mixture is stirred uniformly.

Preferably, after the reaction stage 2 is finished, the temperature of the reaction system is reduced to below 150 ℃, the A6 diluent is added, and the mixture is stirred uniformly. Examples of the a6 diluent include, but are not limited to, urethane-based diluents, alcohol ether-based diluents, and the like, which may be used alone or in combination. More preferably, the a6 diluent is selected from methyl carbamate, ethylene glycol monobutyl ether, ethylene glycol tertiary-butyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, propylene glycol butyl ether, n-butanol, isobutanol, sec-butanol, and the like, which can be used alone or in combination. The addition of the A6 diluent preferably used in the invention can play a role in adjusting the viscosity of a reaction system, adjusting the reaction speed, adjusting the solid content of the resin and the like, and simultaneously, the obtained alkyd resin has extremely low VOC and is odorless and the water solubility of the resin is enhanced.

The A6 diluent can be added into the reaction system at any step of the preparation method of the alkyd resin according to actual conditions without changing the reaction process defined by the invention, and the effect is equivalent to that after the reaction stage 2 is finished, and the implementation of the invention is not influenced. The addition of the A6 diluent did not affect the practice of the invention.

In the preparation method of the alkyd resin, the proportion of each component can be set according to the proportion commonly used in the field, and the implementation of the invention is not influenced.

In a preferred embodiment of the present invention, the mass ratio of the components in the alkyd resin preparation method is as follows:

based on the total mass of the following components,

the mass ratio of the A1 catalyst is 0.05-0.3%, preferably 0.08-0.16%;

the mass ratio of the A2 compound is 20-60%, preferably 22.5-58.5%;

the mass ratio of the A3 compound is 20-40%, preferably 25-39%;

the mass ratio of the A4 compound is 10-40%, preferably 13-37%;

the mass ratio of the A5 compound is 0.1-5%, preferably 1.5-3%.

A preferred preparation method of the invention is exemplified, according to the raw materials and the proportion of the invention, the steps are as follows:

1. adding an A1 catalyst, an A2 compound, an A3 compound and an A4 compound into a reactor in a nitrogen atmosphere, uniformly stirring, heating to 170-180 ℃ for 1-2 hours, then quickly heating to 230-260 ℃ for reaction until the reaction system is clear and transparent, and continuously preserving heat for 0.5-1.5 hours;

2. cooling the reaction system to below 180 ℃, adding part of A5 compound and an organic solvent for condensation reflux, heating to 210-225 ℃ for reaction, wherein the reaction time is 1-2 hours, and carrying out condensation reflux dehydration in the reaction process;

3. cooling the reaction system to below 180 ℃, adding the residual A5 compound, controlling the temperature at 165-175 ℃, and the reaction time at 0.5-1.5 hours, and finishing the reaction system to be clear and transparent;

4. cooling the reaction system to below 150 ℃, adding an optional A6 diluent, uniformly stirring, and discharging.

The invention also provides the alkyd resin, and the alkyd resin is prepared by the preparation method of the alkyd resin.

In a preferred embodiment, the alkyd resin prepared by the preparation method of the alkyd resin provided by the invention contains 60-80% of solid, has an acid value of less than or equal to 15mgKOH/g and a (Fe-Co) colorimetric color number of less than or equal to 6, has a viscosity of 200-800 mPa.s at 25 ℃, has a fineness of less than or equal to 20 μm, and is a reddish brown or yellowish clear transparent liquid.

A preparation method of acrylic acid modified alkyd resin comprises a reaction stage 3 and a reaction stage 4;

in the reaction stage 3, under the condition that a B1 peroxide initiator and a B2 diluent exist, 30-70% of the total mass of the alkyd resin prepared by the alkyd resin preparation method, 30-70% of the total mass of B3 non-functional unsaturated monomers and 0-100% of the total mass of B4 functional unsaturated monomers are mixed for carrying out free radical polymerization reaction, wherein unsaturated monomers of a reaction system are added in the reaction stage 3, and the time for adding the unsaturated monomers into the reaction system is not more than 1.5 hours, preferably not more than 1 hour;

and in the reaction stage 4, after the reaction stage 3 is finished, adding the rest of the B3 non-functional unsaturated monomer and the rest of the B4 functional unsaturated monomer into a reaction system for free radical polymerization, wherein the unsaturated monomer of the reaction system should be added in the reaction stage 4, and the adding time of the unsaturated monomer into the reaction system is 1-4 hours, preferably 1-2 hours.

It should be noted that the "unsaturated monomer which should be added to the reaction system" means B3 non-functional unsaturated monomer and B4 functional unsaturated monomer which should be added in the corresponding steps.

In the reaction stage 3, the addition amount of the B3 non-functional unsaturated monomer is 35-68% of the total mass, and the addition amount of the B4 functional unsaturated monomer is 0-80% of the total mass; in the reaction stage 4, the remaining B3 non-functional unsaturated monomer and the remaining B4 functional unsaturated monomer were added.

Preferably, in the reaction stage 3, the addition amount of the B3 non-functional unsaturated monomer is 40-55% of the total mass, and the addition amount of the B4 functional unsaturated monomer is 0-50% of the total mass; in the reaction stage 4, the remaining B3 non-functional unsaturated monomer and the remaining B4 functional unsaturated monomer were added.

The B1 peroxide initiator may be a peroxide initiator commonly used in the art, and examples thereof include, but are not limited to, Azobisisobutyronitrile (AIBN), Azobisisoheptonitrile (ABVN), dibenzoyl peroxide (BPO), dicumyl peroxide, t-butyl peroxybenzoate (TBPB), di-t-butyl peroxide (DTBP), di-t-amyl peroxide (DTAP), t-butyl hydroperoxide, and the like, which may be used alone or in combination.

The B2 diluent may be a diluent commonly used in the art, and examples thereof include, but are not limited to, urethane-based diluents, alcohol ether-based diluents, and the like, which may be used alone or in combination. Preferably, the B2 diluent is selected from methyl carbamate, ethylene glycol monobutyl ether, ethylene glycol tertiary-butyl ether, dipropylene glycol methyl ether, propylene glycol butyl ether, n-butanol, isobutanol, sec-butanol, and the like, which can be used alone or in combination. The addition of the preferable B2 diluent in the invention can play the roles of adjusting the viscosity of a reaction system, adjusting the molecular weight, adjusting the reaction speed, adjusting the solid content of the resin and the like, and simultaneously, the obtained acrylic acid modified alkyd resin has extremely small VOC and odor and enhances the water solubility of the resin.

The B2 diluent can be added to the reaction system at any step of the preparation method of the acrylic modified alkyd resin according to actual conditions without changing the reaction process defined by the invention, and the implementation of the invention is not influenced.

The B1 peroxide initiator and the B2 diluent are added into the reaction system in multiple steps, so as to control the reaction speed, the viscosity of the reaction system, the reaction progress, the molecular structure of a product, adjust the solid content of the system and the like; generally, the initiator needs to be mixed with a diluent and added to the reaction system, or the initiator and a reaction monomer are mixed and added to the reaction system, or the initiator is directly added to the reaction system, and the common adding method, adding sequence, adding amount and the like are well known in the art, and the implementation of the invention is not influenced by the arrangement according to the common technical scheme.

In a preferred embodiment, the B1 peroxide initiator and B2 diluent are added to the reactor in multiple steps:

1. before the reaction stage 3 is started, all the alkyd resin and 85-98% of the total mass of the B2 diluent are mixed uniformly in advance in a reactor;

2. when the reaction stage 3 begins, mixing 30-35% of the total mass of the B1 peroxide initiator with an unsaturated monomer, and adding into a reactor;

3. when the reaction stage 4 is started, uniformly mixing 45-55% of the total mass of the B1 peroxide initiator and the residual unsaturated monomer, and adding the mixture into a reactor;

4. at the end of reaction stage 4, the remaining B1 peroxide initiator and the remaining B2 diluent were mixed thoroughly and added to the reactor.

The B3 non-functional unsaturated monomer refers to: in one monomer molecule, the functional group is composed of a reactive unsaturated double bond and an optional ester group, and does not contain other functional groups or structures. The other functional group or structure refers to a group or structure having a reactive or special function, and examples thereof include, but are not limited to, a carboxyl group, a hydroxyl group, a vinyl group, an epoxy structure, an amino group, an amide group, a siloxane structure, a carbocyclic structure, a fluorine atom, and the like. Examples of the non-functional unsaturated monomer of B3 include, but are not limited to, styrene, acrylonitrile, vinyl acetate, vinyl versatate (Veova 10), methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-propyl acrylate, lauryl methacrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and the like, and such non-functional unsaturated monomers may be used alone or in combination.

The functional unsaturated monomer B4 refers to a monomer molecule which contains other functional groups or structures besides an unsaturated double bond and an optional ester group. Examples of such other functionalized groups or structures include, but are not limited to, carboxyl groups, hydroxyl groups, vinyl groups, epoxy structures, amino groups, amide groups, siloxane structures, carbocyclic structures, fluorine atoms, and the like. Examples of the B4 functional unsaturated monomer include, but are not limited to, fumaric acid, maleic anhydride, acrylic acid, methacrylic acid, cyclohexyl acrylate, cyclohexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate, glycidyl versatate, divinylbenzene, isobornyl acrylate, isobornyl methacrylate, acetoacetoxy ethyl methacrylate, acrylamide, methacrylamide, diacetone acrylamide, N-hydroxyethyl acrylamide, N-butoxy methacrylamide, monomers containing an unsaturated double bond and a siloxane structure, monomers containing an unsaturated double bond and a fluorine atom, and the like, such functionally unsaturated monomers may be used alone or in combination.

Preferably, the unsaturated monomer of the reaction system should be added in the reaction stage 3, the time for adding the unsaturated monomer into the reaction system is preferably not more than 0.5 hour, the unsaturated monomer can be added at a constant speed or at a non-constant speed by adopting dropping, injecting, spraying and the like, or the unsaturated monomer can be added into the reaction system at one time; the unsaturated monomer of the reaction system should be added in the reaction stage 4, the time for adding the unsaturated monomer into the reaction system is preferably 1.5-2 hours, and the unsaturated monomer can be added in a dropping, injecting, spraying or other mode at a constant speed or a non-constant speed.

Preferably, in the preparation method of the acrylic acid modified alkyd resin, the reaction temperature of the reaction system is 70-160 ℃, and preferably 80-150 ℃.

Preferably, the reaction time of the reaction stage 3 is 5-40 minutes, preferably 8-30 minutes; the reaction time of the reaction stage 4 is 1 to 4 hours, preferably 1.5 to 2 hours.

It should be noted that, after the "reaction time" described throughout the present invention is over, the reactor may optionally be subjected to an incubation operation in order to allow a small amount of unreacted reactants in the reactor to further react, the time taken for the incubation step is not counted in the "reaction time", and the method of operation and purpose of the incubation step are well known in the art, and the performance of the present invention is not affected by the presence or absence of the incubation step.

Preferably, the mass ratio of the B3 non-functional unsaturated monomer to the B4 functional unsaturated monomer is 1-9: 1, preferably 1.5-7: 1, and more preferably 1.3-7: 1. The mass ratio of the B3 non-functional unsaturated monomer to the B4 functional unsaturated monomer is: the ratio of the total mass of the non-functional unsaturated monomers of B3 to the total mass of the functional unsaturated monomers of B4 used in the reaction stages 3 and 4.

In a preferred embodiment, the mass ratio of the components is as follows:

based on the total mass of the alkyd resin, the non-functional unsaturated monomer B3 and the functional unsaturated monomer B4,

the alkyd resin accounts for 40-70%, preferably 50-65%;

the total content of the non-functional unsaturated monomer B3 and the functional unsaturated monomer B4 is 30-60%, preferably 35-50%;

wherein the alkyd resin is measured at 100% solids.

In a preferred embodiment, the B1 peroxide initiator is used in an amount of 1 to 4%, preferably 2.5 to 3.5% of the total mass of the non-functional unsaturated monomer B3 and the functional unsaturated monomer B4.

The using amount of the B2 diluent is 8-18%, preferably 10-14%, based on the total mass of the alkyd resin, the B2 diluent, the B3 non-functional unsaturated monomer and the B4 functional unsaturated monomer, wherein the alkyd resin is measured according to 100% of solid content.

A preferred preparation method of the invention is enumerated, according to the types and proportions of the raw materials:

1. uniformly mixing 85-98% of the total mass of the alkyd resin and the B2 diluent in a reactor in advance under an inert gas atmosphere, heating to 80-150 ℃, and preserving heat for 20-30 minutes;

2. uniformly mixing 30-35% of the total mass of the B1 peroxide initiator, 30-70% of the total mass of the B3 non-functional unsaturated monomer and 0-100% of the total mass of the B4 functional unsaturated monomer, dripping into a reactor within 5-40 minutes, and preserving heat for 10-50 minutes after dripping is finished;

preferably, 30-35% of the total mass of the B1 peroxide initiator, 40-68% of the total mass of the B3 non-functional unsaturated monomer and 0-50% of the total mass of the B4 functional unsaturated monomer are uniformly mixed, and the mixture is dripped into a reactor within 8-30 minutes, and the temperature is kept for 20-40 minutes after the dripping is finished;

3. uniformly mixing 45-55% of the total mass of the B1 peroxide initiator, the rest of B3 non-functional unsaturated monomer and the rest of B4 functional unsaturated monomer, dripping into a reactor within 1.5-2 hours, and preserving heat for 1-2 hours after dripping is finished;

4. uniformly mixing the rest B1 peroxide initiator and the rest B2 diluent, dripping into the reactor within 1-2 hours, preserving heat for 3-5 hours after dripping is finished, and discharging.

The invention also provides acrylic acid modified alkyd resin, which is prepared by the preparation method of the acrylic acid modified alkyd resin.

In a preferred embodiment, the resin prepared by the preparation method of the acrylic acid modified alkyd resin has the solid content of 60-80%, the acid value of 35-42 mgKOH/g, the (Fe-Co) colorimetric color number of less than or equal to 6, the viscosity of 7000-15000 mPa.s at 25 ℃, the fineness of less than or equal to 20 mu m, and the appearance of reddish brown or light yellow clear transparent mucus.

The invention has the beneficial effects that: according to the preparation method of the alkyd resin, the molecular structure of the prepared alkyd resin can be controlled by optimizing and improving the preparation process, raw materials, parameters and the like, and the alkyd resin can be used for preparing acrylic acid modified alkyd resin in water-based paint, so that the final paint has excellent properties, such as high drying speed, high glossiness, good fullness, low VOC (volatile organic compound) emission, excellent mechanical properties and the like; according to the preparation method of the acrylic acid modified alkyd resin, the used alkyd resin is prepared by the preparation method of the alkyd resin, unsaturated monomers are used for modification, and the preparation process, raw materials, parameters and the like are optimized and improved, so that the molecular structure and the molecular weight distribution of the modified resin are more reasonable, the prepared acrylic acid modified alkyd resin has higher monomer conversion rate and excellent storage stability, and when the acrylic acid modified alkyd resin is applied to a coating, the coating has the advantages of high drying speed, high glossiness, good fullness, low VOC (volatile organic Compounds) emission, excellent mechanical property, low comprehensive cost and the like.

According to the resin prepared by the preparation method of the acrylic acid modified alkyd resin, the addition of the acrylic acid monomer is adjusted, the acid value of a final product is correspondingly adjusted, and the acrylic acid modified alkyd resin which is respectively applied to solvent type paint, water-soluble water-based paint and water-dispersible water-based paint can be synthesized. Particularly, when the acrylic modified alkyd resin is used for solvent-based paint, the acrylic modified alkyd resin can be used for preparing the solvent-based paint only by reducing the acid value of the resin (based on 100% solid) to be less than or equal to 15 mgKOH/g; the diluent is not limited to the alcohol, alcohol ether and carbamate solvents, but can be replaced by the conventional solvents with lower cost, such as toluene, xylene, butyl acetate, trimethylbenzene, dipropylene glycol methyl ether acetate and the like. Further, methods of reducing the acid value of the resin, methods of changing the solids content of the resin, and the like are well known to those of ordinary skill in the art. The acid value, the solid content and the like of the resin are simply improved by the method, but the preparation method of the invention is not substantially improved, and still belongs to the protection scope of the invention.

Detailed Description

Example 1

The preparation method of the alkyd resin comprises the following steps:

1. in the nitrogen atmosphere, 225.9g of soya-bean oil acid, 353g of trimethylolpropane, 35.1g of pentaerythritol, 361.8g of isophthalic acid and 1g of tetrabutyl titanate are put into a reaction kettle, the stirring is started, the temperature is raised to 175 ℃, the reaction time is 2 hours, then the temperature is rapidly raised to 245 +/-5 ℃ continuously for reaction, and when the reaction system in the reaction kettle is clear and transparent, the temperature is kept for 30 minutes;

2. cooling the reaction system to 175 ℃, adding 9.2g of maleic anhydride and 60g of butyl acetate, heating to 220 ℃, reacting for 2 hours, and carrying out condensation reflux dehydration in the reaction process;

3. cooling the reaction system to 175 ℃, adding 15g of maleic anhydride, and controlling the temperature of the reaction system at 165 ℃ for reaction for 1 hour;

4. and (3) starting a vacuum pump to remove the reflux solvent butyl acetate, cooling to 150 ℃, adding 602.5g of methyl carbamate, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in example 1 had a solid content of 60.1%, an acid value of 11.8mgKOH/g, a color number 4 in terms of (Fe-Co) color, a viscosity of 600mPa.s, a fineness of 20 μm, and an appearance of a pale yellow, clear and transparent liquid. The preparation method of the acrylic acid modified alkyd resin comprises the following steps:

1. in the nitrogen atmosphere, 491.3g of the prepared alkyd resin and 84.8g of methyl carbamate are put into a reaction kettle, the temperature is raised to 145 ℃, and the temperature is kept for 30 minutes;

2. uniformly mixing 5g of methyl methacrylate, 46.6g of styrene and 1.721g of di-tert-butyl peroxide in advance, then uniformly dripping into the reaction kettle in 10 minutes, and after dripping is finished, keeping the temperature at 145 ℃ for 40 minutes;

3. 11g of methyl methacrylate, 75g of styrene, 34.5g of acrylic acid and 2.582g of di-tert-butyl peroxide are uniformly mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 2 hours, and the temperature is kept at 145 ℃ for 2 hours after the dripping is finished. 4. Premixing 30g of methyl carbamate and 0.861g of di-tert-butyl peroxide, then uniformly dripping into the reaction kettle at a constant speed for 2 hours, preserving the temperature at 145 ℃ for 3.5 hours after finishing dripping, and discharging to obtain the acrylic acid modified alkyd resin.

The acrylic-modified alkyd resin obtained in example 1 had a solid content of 60.2% by weight, an acid value of 35.1mgKOH/g, a (Fe-Co) color number 3, a viscosity of 8000mPa.s at 25 ℃, a fineness of 15 μm, and an appearance of pale yellow, clear, transparent viscous liquid.

Example 2

The preparation method of the alkyd resin comprises the following steps:

1. under the nitrogen atmosphere, putting 180g of soya-bean oil acid, 141g of linoleic acid, 70g of neopentyl glycol, 266g of pentaerythritol, 177g of isophthalic acid, 124g of phthalic anhydride, 17.4g of trimellitic anhydride and 1g of tetrabutyl titanate into a reaction kettle, starting stirring, heating to 180 ℃, reacting for 1.5 hours, then continuously and rapidly heating to 245 ℃ for reaction, starting a vacuum pump to forcibly dehydrate at the later stage of effluent, and continuously preserving the heat for 30 minutes when a reaction system in the reaction kettle is clear and transparent;

2. cooling the reaction system to 175 ℃, adding 9.6g of maleic anhydride, heating to 220 ℃, reacting for 1.5 hours, and forcibly dehydrating by using a vacuum pump in the reaction process;

3. cooling the reaction system to 170 ℃, adding 15g of maleic anhydride, and controlling the temperature of the reaction system at 170 ℃ for reaction for 40 minutes; and then the temperature is reduced.

4. And cooling to 140 ℃, adding 495g of dipropylene glycol methyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in example 2 had a solid content of 65.2%, an acid value of 14.5mgKOH/g, a (Fe-Co) color number 6, a viscosity of 570mPa.s, a fineness of 20 μm, and an appearance of a reddish brown, clear and transparent liquid. The preparation method of the acrylic acid modified alkyd resin comprises the following steps:

1. in the nitrogen atmosphere, 490.3g of the prepared alkyd resin and 75.5g of propylene glycol butyl ether are put into a reaction kettle, the temperature is raised to 125 ℃, and the temperature is kept for 30 minutes;

2. uniformly mixing 10g of methyl methacrylate, 55g of styrene, 3.6g of acrylic acid and 2.286g of tert-butyl peroxybenzoate in advance, then dropwise adding into the reaction kettle at a constant speed for 15 minutes, and after dropwise adding, keeping the temperature at 125 ℃ for 30 minutes;

3. uniformly mixing 40g of methyl methacrylate, 48.3g of styrene, 29g of acrylic acid, 10g of isobornyl methacrylate and 3.429g of tert-butyl peroxybenzoate in advance, then dropwise adding into the reaction kettle at a constant speed for 1.5 hours, and preserving the heat for 4 hours at 125 ℃ after the dropwise adding is finished.

4. 10g of methyl carbamate, 20g of propylene glycol butyl ether and 1.143g of tert-butyl peroxybenzoate are mixed in advance, then the mixture is dripped into a reaction kettle at a constant speed for 1.5 hours, and the temperature is kept at 125 ℃ for 4 hours after the dripping is finished, and the mixture is discharged to obtain the acrylic acid modified alkyd resin.

The acrylic-modified alkyd resin obtained in example 2 had a solid content of 65.0%, an acid value of 37.1mgKOH/g, a color number 5 in terms of (Fe-Co) color, a viscosity of 15000mPa.s at 25 ℃ and a fineness of 15 μm, and had a reddish-brown clear and transparent appearance.

Example 3

The preparation method of the alkyd resin comprises the following steps:

1. under the nitrogen atmosphere, 100g of ricinoleic acid, 305.8g of soya oil acid, 293.6g of trimethylolpropane, 29.2g of pentaerythritol, 200g of isophthalic acid, 46.8g of terephthalic acid and 1g of tetrabutyl titanate are put into a reaction kettle, stirring is started, the temperature is raised to 175 ℃, the reaction time is 2 hours, then the temperature is rapidly raised to 250 ℃ continuously for reaction, and when the reaction system in the reaction kettle is clear and transparent, the temperature is kept for 40 minutes continuously;

2. cooling the reaction system to 170 ℃, adding 9.6g of maleic anhydride and 38g of butyl acetate, heating to 225 ℃, reacting for 1 hour, and carrying out condensation reflux dehydration in the reaction process;

3. cooling the reaction system to 170 ℃, adding 15g of maleic anhydride, and controlling the temperature of the reaction system at 160 ℃ for reaction for 50 minutes;

4. and (3) starting a vacuum pump to remove the reflux solvent butyl acetate, cooling to 140 ℃, adding 400g of propylene glycol butyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in example 3 had a solid content of 69.9%, an acid value of 14.1mgKOH/g, a color (Fe-Co) of No. 4, a viscosity of 190mPa.s, a fineness of 20 μm, and an appearance of a pale yellow, clear, transparent liquid. The preparation method of the acrylic acid modified alkyd resin comprises the following steps:

1. in the nitrogen atmosphere, 457.3g of the prepared alkyd resin and 61.3g of dipropylene glycol methyl ether are put into a reaction kettle, the temperature is raised to 125 ℃, and the temperature is kept for 30 minutes;

2. uniformly mixing 15.2g of methyl methacrylate, 46g of styrene, 4g of acrylic acid and 2.131g of dibenzoyl peroxide in advance, then uniformly dripping into a reaction kettle at a constant speed for 8 minutes, and preserving heat for 50 minutes at 125 ℃ after dripping is finished;

3. 20g of methyl methacrylate, 81.5g of styrene, 26.4g of methacrylic acid and 3.197g of dibenzoyl peroxide are uniformly mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 2 hours, and the temperature is kept at 125 ℃ for 3.5 hours after the dripping is finished.

4. Premixing 30g of dipropylene glycol methyl ether and 1.065g of tert-butyl peroxybenzoate, then uniformly dripping into the reaction kettle within 1.5 hours, preserving heat at 125 ℃ for 4.5 hours after finishing dripping, and discharging to obtain the acrylic acid modified alkyd resin.

The acrylic-modified alkyd resin obtained in example 3 had a solid content of 69.8 wt%, an acid value of 38.2mgKOH/g, a (Fe-Co) color number 4, a viscosity of 14500mPa.s at 25 ℃, a fineness of 20 μm, and an appearance of pale yellow, clear, transparent viscous liquid.

Example 4

The preparation method of the alkyd resin comprises the following steps:

1. under the nitrogen atmosphere, putting 452g of lauric acid, 324g of trimethylolpropane, 75g of terephthalic acid and 1g of tetrabutyl titanate into a reaction kettle, starting stirring, heating to 180 ℃, reacting for 2 hours, then continuously and rapidly heating to 245 ℃ for reaction, and continuously preserving heat for 30 minutes when a reaction system in the reaction kettle is clear and transparent;

2. cooling the reaction system to 180 ℃, adding 8g of maleic anhydride, 100g of phthalic anhydride and 38g of butyl acetate, heating to 220 ℃, reacting for 2 hours, and carrying out condensation reflux dehydration in the reaction process;

3. cooling the reaction system to 170 ℃, adding 16.1g of maleic anhydride, and controlling the temperature of the reaction system at 170 ℃ for reaction for 1 hour;

4. and (3) starting a vacuum pump to remove the reflux solvent butyl acetate, cooling to 140 ℃, adding 200g of methyl carbamate and 187.5g of ethylene glycol tertiary butyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in example 4 had a solid content of 70.1%, an acid value of 14.1mgKOH/g, a (Fe-Co) color number of 0.5, a viscosity of 200mPa.s, a fineness of 20 μm, and a colorless, clear and transparent liquid appearance.

The preparation method of the acrylic acid modified alkyd resin comprises the following steps:

1. putting 456g of the prepared alkyd resin and 69.2g of ethylene glycol tertiary butyl ether into a reaction kettle in a nitrogen atmosphere, heating to 80 ℃, and keeping the temperature for 30 minutes;

2. uniformly mixing 15g of methyl methacrylate, 84.5g of styrene and 1.929g of azobisisobutyronitrile in advance, then dripping into the reaction kettle at a constant speed for 15 minutes, and preserving heat for 1 hour at 80 ℃ after finishing dripping;

3. 32g of methyl methacrylate, 71g of styrene, 27g of acrylic acid, 2g of hydroxyethyl acrylate and 2.894g of azobisisobutyronitrile are uniformly mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 2 hours, and the temperature is kept at 80 ℃ for 2 hours after the dripping is finished.

4. 30g of ethylene glycol tert-butyl ether and 0.965g of azobisisobutyronitrile are mixed in advance, then the mixture is dripped into the reaction kettle at a constant speed for 1.5 hours, and after the dripping is finished, the temperature is kept at 80 ℃ for 6 hours, and the mixture is discharged, so that the acrylic acid modified alkyd resin is obtained.

The acrylic-modified alkyd resin obtained in example 4 had a solid content of 69.9% by weight, an acid value of 35.9mgKOH/g, a (Fe-Co) color number of 0.5, a viscosity of 13200mPa.s at 25 ℃, a fineness of 15 μm, and a colorless, clear and transparent viscous liquid appearance.

Example 5

The preparation method of the alkyd resin comprises the following steps:

1. putting 526g of soya-bean oil acid, 245g of trimethylolpropane, 25g of pentaerythritol, 174.4g of isophthalic acid, 5g of trimellitic anhydride and 1g of tetrabutyl titanate into a reaction kettle in a nitrogen atmosphere, starting stirring, heating to 175 ℃, reacting for 2 hours, then continuously and rapidly heating to 245 ℃ for reaction, and continuously preserving heat for 30 minutes when a reaction system in the reaction kettle is clear and transparent;

2. cooling the reaction system to 175 ℃, adding 9.6g of maleic anhydride and 40g of butyl acetate, heating to 215 ℃, reacting for 2 hours, and carrying out condensation reflux dehydration in the reaction process;

3. cooling the reaction system to 170 ℃, adding 15g of maleic anhydride, and controlling the temperature of the reaction system at 170 ℃ for reaction for 1 hour;

4. starting a vacuum pump to remove a reflux solvent of butyl acetate, cooling to 140 ℃, adding 308.1g of propylene glycol butyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in example 5 had a solid content of 75.0%, an acid value of 14.7mgKOH/g, a color comparison of No. 1 (Fe-Co), a viscosity of 600mPa.s, a fineness of 20 μm, and an appearance of a pale yellow, clear and transparent liquid.

1. in the nitrogen atmosphere, 426.4g of the prepared alkyd resin and 64.5g of propylene glycol butyl ether are put into a reaction kettle, the temperature is raised to 148 ℃, and the temperature is kept for 30 minutes;

2. uniformly mixing 35g of methyl methacrylate, 49.5g of styrene, 10g of methacrylic acid and 2.835g of di-tert-butyl peroxide in advance, then uniformly dripping into the reaction kettle at a constant speed for 18 minutes, and after dripping is finished, keeping the temperature at 148 ℃ for 30 minutes;

3. 50g of methyl methacrylate, 54.5g of styrene, 40g of acrylic acid, 12g of hydroxyethyl acrylate, 32.5g of isobornyl acrylate and 4.253g of di-tert-butyl peroxide are uniformly mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 2 hours, and the temperature is kept at 148 ℃ for 2 hours after the dripping is finished.

4. Premixing 30g of propylene glycol butyl ether and 1.417g of di-tert-butyl peroxide, then uniformly dripping into the reaction kettle at a constant speed for 2 hours, after finishing dripping, keeping the temperature at 148 ℃ for 6 hours, and discharging to obtain the acrylic acid modified alkyd resin.

The acrylic-modified alkyd resin obtained in example 5 had a solid content of 75.2% by weight, an acid value of 36.5mgKOH/g, a (Fe-Co) color number of 0.5, a viscosity of 13200mPa.s at 25 ℃, a fineness of 15 μm, and an appearance of a pale yellow, clear, transparent viscous liquid.

Example 6

The preparation method of the alkyd resin comprises the following steps:

1. in the nitrogen atmosphere, 585.7g of soya-bean oil acid, 234.3g of trimethylolpropane, 23.4g of pentaerythritol, 131.7g of isophthalic acid and 1g of tetrabutyl titanate are put into a reaction kettle, the stirring is started, the temperature is raised to 175 ℃, the reaction time is 1.5 hours, then the temperature is rapidly raised to 240 ℃ continuously for reaction, and when the reaction system in the reaction kettle is clear and transparent, the temperature is kept for 30 minutes continuously;

2. cooling the reaction system to 180 ℃, adding 9.9g of maleic anhydride and 40g of butyl acetate, heating to 220 ℃, reacting for 2 hours, and carrying out condensation reflux dehydration in the reaction process;

3. cooling the reaction system to 170 ℃, adding 15g of maleic anhydride, and controlling the temperature of the reaction system at 165 ℃ for reaction for 1 hour;

4. and (3) starting a vacuum pump to remove a reflux solvent of butyl acetate, cooling to 140 ℃, adding 120g of methyl carbamate and 112.6g of propylene glycol butyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in example 6 had a solid content of 80.1%, an acid value of 14.7mgKOH/g, a (Fe-Co) color number 1, a viscosity of 570mPa.s, a fineness of 20 μm, and an appearance of a pale yellow, clear, transparent liquid.

1. in the nitrogen atmosphere, 399.1g of the prepared alkyd resin and 50g of propylene glycol butyl ether are put into a reaction kettle, the temperature is raised to 150 ℃, and the temperature is kept for 30 minutes;

2. uniformly mixing 15g of methyl methacrylate, 80g of styrene, 12g of methacrylic acid, 52.8g of isobornyl methacrylate and 3.197g of di-tert-butyl peroxide in advance, then uniformly dropping into the reaction kettle at a constant speed for 10 minutes, and preserving heat for 40 minutes at 150 ℃ after dropping;

3. 30g of methyl methacrylate, 56.8g of styrene, 28g of acrylic acid, 10g of hydroxyethyl acrylate, 35.1g of isobornyl acrylate and 4.795g of di-tert-butyl peroxide are uniformly mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 2 hours, and the temperature is kept at 150 ℃ for 2 hours after the dripping is finished.

4. 30g of propylene glycol butyl ether and 1.598g of di-tert-butyl peroxide are mixed in advance, then the mixture is dripped into a reaction kettle at a constant speed for 2 hours, after the dripping is finished, the temperature is kept at 150 ℃ for 5.5 hours, and the mixture is discharged to obtain the acrylic acid modified alkyd resin.

The acrylic-modified alkyd resin obtained in example 6 had a solid content of 80.0% by weight, an acid value of 39.5mgKOH/g, a color number 2 in terms of (Fe-Co) color, a viscosity of 15000mPa.s at 25 ℃ and a fineness of 15 μm, and had a colorless, clear and transparent viscous liquid appearance.

Comparative example 1

The preparation method of the alkyd resin comprises the following steps:

2. cooling the reaction system to 175 ℃, adding 24.6g of maleic anhydride, heating to 220 ℃, wherein the reaction time is 1.5 hours, and forcibly dehydrating by using a vacuum pump in the reaction process; and then the temperature is reduced.

3. And cooling to 140 ℃, adding 495g of dipropylene glycol methyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in comparative example 1 had a solid content of 65.2%, an acid value of 14.8mgKOH/g, a (Fe-Co) color number 6, a viscosity of 650mPa.s, a fineness of 20 μm, and an appearance of a reddish brown clear transparent liquid.

The acrylic-modified alkyd resin obtained in comparative example 1 had a solid content of 65.1%, an acid value of 37.9mgKOH/g, a (Fe-Co) color number 5, a viscosity of 14800mPa. s at 25 ℃, a fineness of 15 μm, and an appearance of a reddish brown clear and transparent viscous liquid.

Comparative example 2

The preparation method of the alkyd resin comprises the following steps:

The alkyd resin obtained in comparative example 2 had a solid content of 69.9%, an acid value of 14.3mgKOH/g, a (Fe-Co) color of No. 4, a viscosity of 200mPa.s, a fineness of 20 μm, and an appearance of a pale yellow, clear, transparent liquid.

2. uniformly mixing 15.2g of methyl methacrylate, 46g of styrene, 4g of acrylic acid and 2.131g of dibenzoyl peroxide in advance, then uniformly dripping into a reaction kettle at a constant speed for 2 hours, and preserving heat for 50 minutes at 125 ℃ after dripping is finished;

The acrylic-modified alkyd resin obtained in comparative example 2 had a solid content of 69.8 wt%, an acid value of 37.5mgKOH/g, a (Fe-Co) color of No. 4, a viscosity of 14000mPa.s at 25 ℃, a fineness of 20 μm, and an appearance of pale yellow, clear, transparent viscous liquid.

Comparative example 3

The preparation method of the alkyd resin comprises the following steps:

2. cooling the reaction system to 180 ℃, adding 24.1g of maleic anhydride, 100g of phthalic anhydride and 38g of butyl acetate, heating to 220 ℃, reacting for 2 hours, and carrying out condensation reflux dehydration in the reaction process; after the reaction was completed, it was cooled to 180 ℃.

3. And (3) heating the kettle to 180 ℃, starting a vacuum pump to remove a reflux solvent of butyl acetate, cooling to 140 ℃, adding 200g of methyl carbamate and 187.5g of ethylene glycol tert-butyl ether, uniformly stirring, and discharging to obtain the alkyd resin.

The alkyd resin obtained in comparative example 3 had a solid content of 70.1%, an acid value of 14.6mgKOH/g, a (Fe-Co) color number of 0.5, a viscosity of 210mPa.s, a fineness of 20 μm, and a colorless, clear and transparent liquid appearance.

2. 47g of methyl methacrylate, 155.5g of styrene, 27g of acrylic acid, 2g of hydroxyethyl acrylate and 3.473g of azobisisobutyronitrile are uniformly mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 3.5 hours, and the temperature is kept at 80 ℃ for 1.5 hours after the dripping is finished.

3. 15g of ethylene glycol tert-butyl ether and 1.447g of azodiisobutyronitrile are mixed in advance, and then the mixture is dripped into a reaction kettle at a constant speed for 50 minutes, and the temperature is kept for 1 hour at 80 ℃ after the dripping is finished.

4. 15g of ethylene glycol tert-butyl ether and 0.868g of azodiisobutyronitrile are mixed in advance, then the mixture is dripped into the reaction kettle at a constant speed for 50 minutes, the temperature is kept at 80 ℃ for 4.5 hours after the dripping is finished, and the mixture is discharged to obtain the acrylic acid modified alkyd resin.

The acrylic-modified alkyd resin obtained in comparative example 3 had a solid content of 70.2% by weight, an acid value of 36.5mgKOH/g, a (Fe-Co) color of 0.5, a viscosity of 13600mPa.s at 25 ℃ and a fineness of 15 μm, and had a colorless, clear and transparent viscous liquid appearance.

TABLE 1 raw materials and specifications (parts by mass) for the preparation of the paint films

The preparation method of the test paint film comprises the following steps: the raw materials in the table 1 are uniformly mixed according to the proportion, sprayed on a polished tin plate, baked for 30 minutes at 130 ℃, and the thickness of the paint film is about 30-35 μm, which corresponds to the test paint films of examples 1-6 and comparative examples 1-3 after baking.

The test results of the test paint films of examples 1 to 6 and comparative examples 1 to 3 are shown in Table 2.

TABLE 2 evaluation data sheet for water-based amino baking varnish film

Claims

1. The preparation method of the alkyd resin is characterized by comprising a reaction stage 1 and a reaction stage 2, wherein the reaction stage 1 is to mix reaction raw materials to react in the presence of an A1 catalyst, and the reaction raw materials comprise an A2 compound, an A3 compound and an A4 compound, wherein the A2 compound is vegetable oleic acid and/or synthetic fatty acid with 8 to 20 carbon atoms, the A3 compound is a hydroxyl compound, and the A4 compound is saturated carboxylic acid and/or saturated anhydride;

2. The process according to claim 1, wherein the reaction temperature of the reaction stage 1 is 150 to 280 ℃, preferably 170 to 260 ℃; the reaction temperature of the reaction stage 2 is 150-240 ℃, and preferably 160-225 ℃.

3. The method according to claim 1 or 2, characterized in that the reaction stage 2 comprises the following steps: the A5 compound is added into the reaction system for reaction in the reaction stage 2-1 and the reaction stage 2-2 respectively.

4. A process according to any one of claims 1 to 3, characterised in that the reaction temperature in the reaction stage 2-1 is between 180 and 240 ℃, preferably between 210 and 225 ℃ and the reaction temperature in the reaction stage 2-2 is between 150 and 190 ℃, preferably between 160 and 175 ℃.

5. The process according to any one of claims 1 to 4, characterized in that the A5 compound added in the reaction stage 2-1 is present in an amount of 20 to 60%, preferably 30 to 50%, more preferably 30 to 40% of the total mass of the A5 compound.

6. The method according to any one of claims 1 to 5, wherein the alkyd resin is prepared by the following method for preparing the alkyd resin:

based on the total mass of the following components,

the mass ratio of the A1 catalyst is 0.05-0.3%, preferably 0.08-0.16%;

the mass ratio of the A2 compound is 20-60%, preferably 22.5-58.5%;

the mass ratio of the A3 compound is 20-40%, preferably 25-39%;

the mass ratio of the A4 compound is 10-40%, preferably 13-37%;

the mass ratio of the A5 compound is 0.1-5%, preferably 1.5-3%.

7. An alkyd resin, characterized in that it has been prepared according to the process of any one of claims 1-6.

8. The preparation method of the acrylic acid modified alkyd resin is characterized by comprising the following steps: reaction stage 3 and reaction stage 4;

the reaction stage 3 is to mix 30-70% of the total mass of the alkyd resin prepared by the method of any one of claims 1-6, 30-70% of the total mass of the B3 non-functional unsaturated monomer and 0-100% of the total mass of the B4 functional unsaturated monomer in the presence of a B1 peroxide initiator and a B2 diluent to perform a free radical polymerization reaction, wherein the unsaturated monomer of the reaction system should be added in the reaction stage 3, and the time for adding the unsaturated monomer into the reaction system is not more than 1.5 hours, preferably not more than 1 hour;

9. The method as claimed in claim 8, wherein in the reaction stage 3, the B3 non-functional unsaturated monomer is added in an amount of 35-68% of the total mass, and the B4 functional unsaturated monomer is added in an amount of 0-80% of the total mass; in the reaction stage 4, adding the rest of the B3 non-functional unsaturated monomer and the rest of the B4 functional unsaturated monomer;

10. The method of claim 8 or 9, wherein the B2 diluent is selected from one or more of methyl carbamate, ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether, dipropylene glycol methyl ether, propylene glycol butyl ether, n-butanol, isobutanol, and sec-butanol.

11. The method according to any one of claims 8 to 10, wherein the unsaturated monomer of the reaction system should be added in the reaction stage 3 for a time period not exceeding 0.5 hour, and the unsaturated monomer of the reaction system should be added in the reaction stage 4 for a time period of 1.5 to 2 hours.

12. The method according to any one of claims 8-11, wherein the reaction temperature of the reaction system in the preparation method of the acrylic modified alkyd resin is 70-160 ℃, preferably 80-150 ℃.

13. The method according to any one of claims 8 to 12, wherein the mass ratio of the B3 non-functional unsaturated monomer to the B4 functional unsaturated monomer is 1-9: 1, preferably 1.5-7: 1, and more preferably 1.3-7: 1.

14. The method according to any one of claims 8 to 13, wherein the mass ratios of the components are as follows: based on the total mass of the alkyd resin, the non-functional unsaturated monomer B3 and the functional unsaturated monomer B4,

the alkyd resin accounts for 40-70%, preferably 50-65%;

the total content of the non-functional unsaturated monomer B3 and the functional unsaturated monomer B4 is 30-60%, preferably 35-50%; wherein the alkyd resin is measured at 100% solids.

15. An acrylic modified alkyd resin, characterized in that it is prepared according to the method of any one of claims 8-14.