WO2023231060A1 - Water-based polyester modified silicone resin, and preparation method therefor and application thereof - Google Patents

Abstract

The present invention relates to the technical field of polymer synthesis, relates to a silicone polymer, and in particular to a water-based polyester modified silicone resin, and a preparation method therefor and an application thereof. The water-based polyester modified silicone resin has the following structural general formula (1), R1 is selected from methylene or benzylidene, R2 is selected from ethylidene, propylidene, phenylene or 2,5-dimethyl-1,4-phenylene, and x is a positive integer from 5 to 30; M is a hydroxyl-terminated polyester modified silicone resin formed by condensation of hydroxyl-terminated polyester and a silicone intermediate, the terminal hydroxyl group is an alkyl hydroxyl group, and the silicone intermediate has a silanol or alkoxy active group. The water-based polyester modified silicone resin has the characteristics of good water-based self-emulsifying performance, high molecular structure stability in an aqueous phase, and good high-temperature resistance of a material, and can be widely applied to the field of high-temperature resistant coatings, such as high-temperature pipe anti-corrosion coatings, cooking utensil coatings or small appliance coatings.

Description

A kind of water-based polyester modified silicone resin, preparation method and application thereof Technical field

The invention relates to a silicone polymer, in particular to a water-based polyester modified silicone resin, a preparation method and its application, and belongs to the technical field of polymer synthesis.

Background technique

Silicone resin is a semi-inorganic polymer with a highly cross-linked structure. Its special composition and molecular structure make it have the dual characteristics of organic resin and inorganic materials. It is resistant to high temperatures, moisture, water, rust, cold, and weather. , excellent electrical insulation properties and other characteristics, but it has been widely used. However, current liquid silicone resins are still mainly oily solutions, which brings greater environmental pollution pressure to material applications. Some companies have begun to develop water-based silicone resins, which are mainly divided into two technical routes. One is to add an external emulsifier, and the emulsification effect of this technical route is difficult to control; the other is to use hydrophilic end-capping groups in the resin, and the material Good emulsification effect and high dispersion stability. The present invention mainly provides a water-based silicone resin technology and provides solutions for the green application of silicone resin.

Patent CN106220838 discloses a hydrophobic and heat-resistant silicone-modified polyester resin and its preparation method. The silicone-modified polyester resin described in the patent is a polyol, polybasic acid, and organic silicon intermediate under solvent and catalyst conditions. Obtained by polymerization, the product is a polyester-modified silicone resin solution with high solvent content, which is not conducive to environmental protection.

Patent CN104726021 discloses a modified resin aqueous dispersion. The modified resin dispersion described in the patent is polysiloxane-modified polyester resin. The water-based effect is achieved by adding a surfactant containing polyvinyl alcohol. The resin dispersion The medium dispersed particle size ranges from 300 to 1500nm. Since the emulsification effect is supported by the externally added polyvinyl alcohol surfactant, and the dispersed particles in the dispersion have a large size and a wide distribution, the stability period of the dispersion is subject to certain limitations and the stability period is short.

Contents of the invention

The object of the present invention is to provide a water-based polyester modified silicone resin, which has the characteristics of good water-based self-emulsifying performance, high molecular structure stability in the water phase, and good high-temperature resistance of the material. , can be widely used in high-temperature resistant coating fields, such as high-temperature pipeline anti-corrosion, cookware or small household appliance coatings.

The technical solutions adopted by the present invention to solve the technical problems are:

A kind of water-based polyester modified silicone resin, the water-based polyester modified silicone resin has the following general structural formula:

in,

R ₁ is selected from methylene or benzylidene,

R ₂ is selected from ethylene, propylene, phenylene or 2,5-dimethyl-1,4-phenyl,

x is a positive integer from 5 to 30;

M is a hydroxyl-terminated polyester-modified silicone formed by the condensation of a hydroxyl-terminated polyester and an organic silicone intermediate, and the terminal hydroxyl group is an alkyl hydroxyl group. The organic silicone intermediate has a silanol or alkoxy active group.

The present invention performs an esterification reaction on the condensation product of a traditional alkyl hydroxyl-terminated polyester and an organic silicone intermediate to convert the alkyl hydroxyl end group into a phenolic hydroxyl end group structure, and at the same time obtains the alkyl hydroxyl end group polyester. Hydrolytic stability, and high Mannich reactivity of phenolic hydroxyl end groups. On the basis of the phenolic hydroxyl compound, Mannich reaction is further performed to obtain a water-based polyester-modified silicone resin with an amine-terminated structure.

Preferably, the molecular weight of the silicone intermediate is 700-5000; the molecular weight of the hydroxyl-terminated polyester is 800-5000, and the average terminal hydroxyl functionality is 2-10.

Preferably, the proportion of phenyl groups in the side groups of the organosilicon intermediate is not less than 50%. Further, the proportion of phenyl groups in the side groups of the organosilicon intermediate is 80%-100%.

Preferably, the hydroxyl-terminated polyester is formed by the condensation of polybasic acid and alkyl polyol; alkyl polyol and polybasic acid are calculated according to the material ratio of functional group n(-OH)/n(-COOH), n (-OH)/n(-COOH)=1.15～2. The polymerization reaction time is usually 1 to 4 hours.

Preferably, the polybasic acid is selected from one or more of terephthalic acid, isophthalic acid, 2-methyl-1,4-phthalic acid, and 1,4-cyclohexanedicarboxylic acid;

The alkyl polyol is selected from one or more of neopentyl glycol, trimethylolpropane, trimethylolethane or pentaerythritol.

Preferably, the relative molecular mass ratio of the silanol or alkoxy active group of the organosilicon intermediate to the organosilicon intermediate is 0.01 to 0.1.

Preferably, the ratio of the amine end group R ₂ -NH ₂ of the water-based polyester modified silicone resin to the amount of the water-based polyester modified silicone resin is x,

When x is 5 to 15, the water-based polyester modified silicone resin is acidified to form an ammonium salt, and then mixed with an appropriate amount of water to form a self-emulsifying dispersion;

When x is 10 to 30, the water-based polyester modified silicone resin is mixed with an appropriate amount of water to form a self-emulsifying dispersion. The water-based polyester-modified silicone resin exhibits different water-based effects depending on the amine end group content, and the two emulsified dispersions obtained have good storage stability.

Specifically, the present invention is prepared by the following materials and reaction conditions.

In the synthesis of water-based polyester modified silicone resin, each step is carried out under dynamic stirring.

In the synthesis of water-based polyester modified silicone resin, each step is carried out under the protection of inert gases such as nitrogen.

The hydroxyl-terminated polyester can be a commercially available hydroxyl-terminated polyester with an alkyl hydroxyl end group, or it can be independently synthesized. To facilitate the distinction, an independent synthesis scheme is used in this description. The hydroxyl-terminated polyester is produced by polycondensation of polyol and polybasic acid, wherein the polyol is an alkyl polyol.

Preferably, the water-based polyester modified silicone resin is made of the following raw materials by weight:

100 parts of hydroxyl-terminated polyester, 50 to 200 parts of silicone intermediate, 0.5 to 2 parts of catalyst, 10 to 50 parts of p-hydroxybenzoic acid, 10 to 40 parts of aldehyde, 8 to 40 parts of diamine, and 50 to 100 parts of solvent;

The aldehyde is selected from benzaldehyde, paraformaldehyde, trimerformaldehyde or a mixture of one or more of formaldehyde, preferably benzaldehyde or paraformaldehyde;

The diamine is selected from one or more mixtures of ethylenediamine, propylenediamine, butylenediamine, phenylenediamine, xylylenediamine, phenylenediethylamine or 3-methylamine phenylethylamine, preferably ethylenediamine. Amine, phenylenediamine, 3-methylamine phenylethylamine;

The solvent is selected from one or a mixture of one or more of cyclopentanol, ethylene glycol or ethylene glycol monoethyl ether, preferably ethylene glycol monoethyl ether.

In the present invention, the selection of the catalyst for resin synthesis is common knowledge in the art. Generally, a phthalate catalyst can be selected, preferably one of tetraethyl titanate, tetrabutyl titanate, and butyltin dilaurate. Or a mixture of several. Tetrabutyl titanate is more preferred. Calculated in terms of mass percentage, the amount of catalyst used is 0.5 to 2% by weight of the organic silicon intermediate.

Silicone intermediate used in the synthesis of the polyester modified silicone resin

R is selected from H, CH ₃ and C ₂ H ₅ . The relative molecular mass ratio of the active group to the organic silicon intermediate is m (active group)/m (molecular weight) = 0.01 to 0.2, preferably 0.01 to 0.1. Silicone intermediates can be commercial silicone intermediates, such as those from Wacker

SY231、

SY300,

IC232、

SIC368,

IC678、

IC836, Shin-Etsu's KR211, KR212, KR214, KR216, Dow Corning's RSN-6018, RSN-3037, RSN-3074, RSN-0233, RSN-0249, Dow's DOWSIL ^TM RSN-0217, DOWSIL ^TM RSN-0220 , DOWSIL ^TM RSN-0233, DOWSIL ^TM RSN-0249, DOWSIL ^TM RSN-0255, DOWSIL ^TM RSN-6018, one or more mixtures.

A method for preparing the water-based polyester modified silicone resin, which method includes the following steps:

S1. In a catalyst and an inert atmosphere, the hydroxyl-terminated polyester and the organic silicone intermediate undergo a condensation reaction at 130 to 150°C to obtain polyester-modified silicone;

The mass ratio of hydroxyl-terminated polyester and silicone intermediate is 0.5-2:1; preferably 0.8-1.5:1, more preferably 1-1.2:1;

S2. In an inert atmosphere, perform an esterification reaction between the polyester-modified silicone obtained by the condensation of S1 and p-hydroxybenzoic acid at 180-220°C to obtain compound A;

The mass ratio of polyester modified silicone to p-hydroxybenzoic acid is 1:5~25;

S3. Mix the compound A obtained in S2 with aldehyde and diamine evenly, and conduct Mannich reaction at 80-120°C in the presence of a solvent to obtain a water-based polyester-modified silicone resin with amine end groups;

The mass ratio of compound A to aldehyde and diamine is m (compound A): m (aldehyde): m (diamine) = 100: 5 to 20: 5 to 20.

The reaction route diagram of the preparation method of the water-based polyester modified silicone resin is:

The para-hydroxybenzoic acid used to synthesize compound A is preferably pulverized para-hydroxybenzoic acid powder.

The compound A has

Structural characteristics, y is a positive integer from 5 to 30.

Preferably, in S1, the mass ratio of hydroxyl-terminated polyester and silicone intermediate is 1:1-1.5, in S2, the mass ratio of polyester-modified silicone and p-hydroxybenzoic acid is 1:10-15; S3 In , the mass ratio of compound A to aldehyde and diamine is m (compound A): m (aldehyde): m (diamine) = 100: 5 to 10: 5 to 10.

Preferably, when the solvent in S3 is ethylene glycol monoethyl ether, in terms of mass ratio, m (compound A): m (ethylene glycol monoethyl ether) = 10: 1 to 4.

Preferably, the synthesis of the hydroxyl-terminated polyester adopts the following method: polybasic acid and glycol are reacted at 150-200°C for 0.5-1.5 hours, then trihydric alcohol or tetrahydric alcohol is added, and the reaction is continued for 1-2 hours, and then the temperature is raised React at 200-230°C for 2-3 hours, and obtain multi-functional hydroxyl-terminated polyester after dehydration and condensation.

Preferably, the dihydric alcohol, trihydric alcohol or tetrahydric alcohol is selected from the group consisting of ethylene glycol, propylene glycol, glycerol, butylene glycol, butanetriol, neopentyl glycol, pentatriol, pentaerythritol, trihydroxyl One or a combination of several of methylpropane, trimethylolethane, benzenedimethanol, and benzenediethanol; preferably ethylene glycol, glycerol, neopentyl glycol, pentaerythritol, trimethylolpropane, One or more combinations of trimethylolethane, more preferably one or more combinations of neopentyl glycol, trimethylolpropane, trimethylolethane, and pentaerythritol;

The polybasic acid is selected from terephthalic acid, isophthalic acid, terephthalic acid, isophthalic acid, 2-methyl-1,4-phthalic acid, trimellitic anhydride, pyromellitic anhydride, 2,5-di One or a combination of methyl-1,4-phthalic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, and 1,4-cyclohexanedicarboxylic acid; preferably p-benzene In dicarboxylic acid, isophthalic acid, 2-methyl-1,4-phthalic acid, trimellitic anhydride, 2,5-dimethyl-1,4-phthalic acid, 1,4-cyclohexanedicarboxylic acid One or a combination of several, more preferably terephthalic acid, isophthalic acid, 2-methyl-1,4-phenylene dicarboxylic acid, 2,5-dimethyl-1,4-phenylene dicarboxylic acid One or a combination of formic acids.

An application of the water-based polyester modified silicone resin according to the present invention in the preparation of low VOC hot water resistant silicone coating.

Preferably, the water-based polyester-modified silicone resin is mixed with water to form a self-emulsifying dispersion, or is acidified to form a salt and then mixed with water to form a water-based polyester-modified silicone resin self-emulsifying dispersion; the obtained self-emulsifying dispersion Mix with necessary cross-linking agents, pigments, fillers and functional additives to prepare low VOC hot water resistant silicone coatings. The self-emulsifying dispersion replaces the external emulsified oily silicone resin emulsion raw material of water-based silicone coatings in the prior art. The acid used for acidification is selected from one or both of formic acid or phosphoric acid, with phosphoric acid being preferred. Low VOC hot water resistant silicone coating made of water-based polyester modified silicone resin, sprayed and baked at high temperature to form a film, the high temperature resistant silicone coating is obtained.

The technical difficulty of the present invention lies in: reasonable selection and proportioning of raw materials so that the resin can obtain the performance characteristics of self-emulsification, hydrolysis resistance, and high temperature resistance. Compared with the prior art, the advantages of the present invention are:

1. The water-based polyester modified silicone resin of the present invention can be used to make high-temperature-resistant water-based silicone coatings instead of existing oil-based silicone resins, greatly reducing the safety of production, storage, and use of silicone coatings and reducing solvent emissions.

2. The water-based polyester modified silicone resin of the present invention improves the hydrolysis resistance of the resin through the selection of synthetic monomers of the polyester resin;

3. The water-based polyester modified silicone resin of the present invention can flexibly control the water dispersion of the resin by regulating the content of amine end groups.

Through the introduction of p-hydroxybenzoic acid, higher Mannich reaction activity is obtained;

The amine end groups introduced by Mannich reaction have the advantages of stable structure and high group content. The resin produced is easier to be water-based, and the final product's water-based self-emulsifying dispersion has higher storage stability.

Description of the drawings

Figure 1 is a scanning electron microscope image of water-based polyester modified silicone resin dispersion particles;

Figure 2 is a scanning diagram of the particle size of the water-based polyester modified silicone resin emulsion dispersion.

Detailed ways

The technical solution of the present invention will be further described in detail below through specific examples. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any formal modifications and/or changes made to the present invention will fall within the protection scope of the present invention.

In the present invention, unless otherwise specified, all parts and percentages are units of weight, and the equipment and raw materials used can be purchased from the market or are commonly used in the field. The methods in the following examples are all conventional methods in the art unless otherwise specified.

The sources of raw materials in the following examples are as follows:

Silicone intermediate, Dow Corning RSN0217; Wacker

IC836.

Comparative Examples 1 to 3 and Examples 1 to 6 Synthesis of hydroxyl-terminated polyester

Carry out the synthesis of hydroxyl-terminated polyester according to the formula in Table 1, measure according to the formula in Table 1, add polyol to the reaction kettle, slowly raise the temperature to 120~150°C under nitrogen protection, add the measured amount of polybasic acid under stirring, and then Slowly heat up to 150~180℃, react for 0.5~1h, continue to heat up to 220℃, react at a constant temperature, count the collected condensed water, after the condensed water is close to the theoretical yield, detect the acid value of the resin, the acid value reaches 2~6KOHmg/g When, the synthesis of hydroxyl-terminated polyester is completed.

Table 1 Raw material components and content (unit: g)

Comparative Examples 1 to 3 used hydroquinone as the polyol in the formula to analyze the impact of containing a large amount of phenol βH in the polyester chain segment. The test data (Table 3) shows that the phenolic hydroxyl groups in the polyester chain segment will Consumes aldehydes and diamines, thereby affecting the water-based effect of the resin. Examples 1 to 6 are used to investigate: 1. The material ratio of the functional groups n(-OH)/n(-COOH) of alkyl polyols and polybasic acids, and the water-based self-emulsifying performance of water-based polyester modified silicone resin. 2. The influence of the material ratio of alkyl polyol and polybasic acid n (polyol)/n (polyacid) on the water-based self-emulsifying performance of water-based polyester modified silicone resin.

The listed Comparative Examples 1 to 3 and Examples 1 to 6 all follow the same test conditions and the reaction cut-off conditions where the acid value reaches 2 to 6 KOHmg/g.

Comparative Examples 4-6, Examples 7-12 Synthesis of Water-Based Polyester Modified Silicone Resin

The synthetic raw material components and proportions of water-based polyester modified silicone resin are shown in Table 2. After the hydroxyl-terminated polyester synthesis reaction is completed, the materials can be directly added in proportion, or the reaction can be stopped and the hydroxyl-terminated polyester is encapsulated. According to the reaction plan, an appropriate amount of hydroxyl-terminated polyester is taken for the next reaction.

Table 2 (unit: g)

The synthesis method of water-based polyester modified silicone resin is:

S1. Add a measured amount of hydroxyl-terminated polyester and raise the temperature to 140°C. After the temperature stabilizes, keep stirring and add a measured amount of silicone intermediate, then add the catalyst butyl phthalate, continue stirring and react for 2.5 hours to obtain the modified polyester. Silicone resin compound.

S2. Add a measured amount of p-hydroxybenzoic acid to the reactant obtained in S1, keep stirring and raise the temperature to 190°C for 1 hour, then raise the temperature to 210°C and react for 2 hours.

S3. Lower the temperature of the reaction system in S2 to 180°C, add a measured amount of ethylene glycol monoethyl ether (solvent), and then continue to lower the temperature to 90°C. After the temperature of the material is stabilized, conduct the Mannich reaction. Add a measured amount of benzaldehyde and ethylenediamine, and react at a constant temperature of 90°C for 3 hours under stirring to obtain an amine-terminated water-based polyester-modified silicone resin.

Application examples and analysis of water-based self-emulsifying dispersions

Take the water-based polyester modified silicone resin synthesized in the example, add an appropriate amount of water, mix, and stir to obtain a self-emulsifying dispersion with a solid content of 40%. Control the stirring rate to 1000~2500rpm and the stirring time to 20~40min.

When the amine end group content of the water-based polyester-modified silicone resin synthesized in the embodiment is too low to be directly dispersed in water, it can be acidified into a salt in advance and then dispersed in water to maintain the water-based polyester modification in the self-emulsifying dispersion. The solid content of silicone resin is 40%.

The ratio of the amine end group R ₂ -NH ₂ of the water-based polyester modified silicone resin to the amount of the water-based polyester modified silicone resin is x, where the amount of the water-based polyester modified silicone resin is The amount is calculated by the light scattering method. The amount of the amine end group R ₂ -NH ₂ of the water-based polyester modified silicone resin is the amount of the diamine (ethylenediamine, phenylenediamine) in the raw material. .

Take the water-based polyester modified silicone resin prepared in Example 8 and configure it into a self-emulsifying dispersion of water-based polyester modified silicone resin with a solid content of 40% according to the above method. ① Add water and dilute to a solid content of 0.1%. Take A drop of liquid was dropped onto the aluminum foil, vacuum dried, and then a scanning electron microscope analysis was performed on the material. The results are shown in Figure 1. Drying conditions: vacuum degree 0.085MPa, temperature 25℃, cycle 24h. ②The self-emulsifying dispersion with a solid content of 40% was used to detect the particle size of the dispersed particles on a laser particle size analyzer. The results are shown in Figure 2.

The water-based polyester-modified silicone resin prepared in Table 2 was prepared into 500g of self-emulsifying dispersion of water-based polyester-modified silicone resin with a solid content of 40% according to the proportions shown in Table 3. The water-based polyester-modified silicone resin was loaded into a transparent container with a diameter of 10 cm. The storage resistance of the dispersion was analyzed in PET plastic bottles, and the results are shown in Table 3. Storage resistance performance analysis method: store at 23°C and observe the settlement and stratification every 10 days. If 1/3 of the height is clear, it is judged as settlement and stratification failure; after 180 days, stir the material in the bottle to determine the material adhesion. , no obvious bonding.

Table 3 (unit: g)

It can be seen from the storage stability data of the resin dispersion that the water-based polyester-modified silicone resin aqueous dispersion of the present invention has excellent storage resistance. Among them, the use of phenol-containing raw materials during polyester synthesis will affect the access position of the Mannich reaction amine end group, thereby affecting the hydrophilicity of the resin; adding high content of silicone intermediates and solvents will affect the water-based polyester modified silicone resin. The storage stability of the dispersion has a certain impact; the selection of polybasic acids and polyols has a certain impact on the storage stability of the water-based polyester modified silicone resin dispersion.

Comparative Examples 8-9 and Examples 20-21

In order to verify the effect, commercially available oily polyester modified silicone resin (Changxing 5071-s-60, Comparative Example 7) and commercially available oily polyester modified silicone resin (WACKER SILRES MPF50E (50%) were used respectively. , Comparative Example 8), the water-based polyester modified silicone resin (Examples 13 and 14) prepared in Examples 8 and 11 of the present invention is mixed with the necessary cross-linking agent, pigments, fillers and functional additives to prepare a coating , the coating formula is shown in Table 4.

The data listed in Table 4 are all the mass of active ingredients, the solvent or dispersant contained in the active materials, and the total mass of the listed formula is 100Kg.

Among them, the materials in Table 4, the resin of Example 8 and the resin of Example 11, were added in the form of a resin self-emulsifying dispersion with a solid content of 40%. For its preparation method, see Application Examples.

Table 4 (Unit: kg)

The prepared coating is sprayed on the cast aluminum substrate and baked at 150°C/10min and 280°C/10min to obtain the silicone coating. The coating properties are shown in Table 5.

table 5

Test items	Test Methods	Comparative example 8	Comparative example 9	Example 20	Example 21
gloss, °	GB/T 9754	92	25	85	79
Thickness, μm	GB/T 13452	15-18	15-18	15-18	15-18
hardness	GB/T 6739	4H	H	3H	3H
hot hardness	200℃, pencil	2H	HB	H	H
adhesion	GB/9286	Level 0	Level 1	Level 0	Level 0
boiling water adhesion	GB/T 32095	Level 0	level 2	Level 1	Level 0
Impact resistance	50cm, drop weight method	Not cracked	Not cracked	Not cracked	Not cracked
Ethanol test	95% ethanol, 24h	No significant changes	No significant changes	No significant changes	No significant changes

It can be seen from the coating test data that the paint film made by using the water-based polyester modified silicone resin of the present invention has high gloss, good thermal hardness, superior water resistance and solvent resistance, and has the same performance as the paint film made by traditional oil-based silicone paint. Close; the use effect meets the protection and aesthetic requirements of high-temperature scenes such as non-stick pans.

Each embodiment in this specification is described in a progressive manner. Each embodiment focuses on its differences from other embodiments. The same or similar parts between various embodiments can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple. For relevant details, please refer to the description in the method section.

The above is a detailed introduction to the water-based polyester modified silicone resin, preparation method and application provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and the core idea of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of the claims of the present invention.

Claims (15)

1. A water-based polyester modified silicone resin, characterized in that the water-based polyester modified silicone resin has the following general structural formula:

   

   in,

   R ₁ is selected from methylene or benzylidene,

   R ₂ is selected from ethylene, propylene, phenylene or 2,5-dimethyl-1,4-phenyl,

   x is a positive integer from 5 to 30;

   M is a hydroxyl-terminated polyester-modified silicone formed by the condensation of a hydroxyl-terminated polyester and an organic silicone intermediate, and the terminal hydroxyl group is an alkyl hydroxyl group. The organic silicone intermediate has a silanol or alkoxy active group.
2. The water-based polyester modified silicone resin according to claim 1, characterized in that: the molecular weight of the silicone intermediate is 700-5000; the molecular weight of the hydroxyl-terminated polyester is 800-5000, and the average terminal hydroxyl functionality is It is 2~10.
3. The water-based polyester modified silicone resin according to claim 1, wherein the proportion of phenyl groups in the side groups of the silicone intermediate is not less than 50%.
4. The water-based polyester modified silicone resin according to claim 1, characterized in that: the hydroxyl-terminated polyester is formed by the condensation of polybasic acid and alkyl polyol; alkyl polyol and polybasic acid are divided into functional groups n ( Calculation of the substance ratio of -OH)/n(-COOH), n(-OH)/n(-COOH)=1.15~2.
5. The water-based polyester modified silicone resin according to claim 4, characterized in that: the polybasic acid is selected from the group consisting of terephthalic acid, isophthalic acid, 2-methyl-1,4-phthalic acid, 1,4 - One or more types of cyclohexanedicarboxylic acids;

   The alkyl polyol is selected from one or more of neopentyl glycol, trimethylolpropane, trimethylolethane or pentaerythritol.
6. The water-based polyester modified silicone resin according to claim 1, characterized in that: the relative molecular mass ratio of the silanol or alkoxy active group of the silicone intermediate to the silicone intermediate is 0.01 to 0.1 .
7. The water-based polyester modified silicone resin according to claim 1, characterized in that: the amine end group R ₂ -NH ₂ of the water-based polyester modified silicone resin and the water-based polyester modified silicone resin are substances The ratio of the quantities is x,

   When x is 5 to 15, the water-based polyester modified silicone resin is acidified to form an ammonium salt, and then mixed with an appropriate amount of water to form a self-emulsifying dispersion;

   When x is 10 to 30, the water-based polyester modified silicone resin is mixed with an appropriate amount of water to form a self-emulsifying dispersion.
8. The water-based polyester modified silicone resin according to claim 1, characterized in that the water-based polyester modified silicone resin is made of the following raw materials by weight:

   100 parts of hydroxyl-terminated polyester, 50 to 200 parts of silicone intermediate, 0.5 to 2 parts of catalyst, 10 to 50 parts of p-hydroxybenzoic acid, 10 to 40 parts of aldehyde, 8 to 40 parts of diamine, and 50 to 100 parts of solvent;

   The aldehyde is selected from one or a mixture of benzaldehyde, paraformaldehyde, trimerformaldehyde or formaldehyde;

   The diamine is selected from one or more mixtures of ethylenediamine, propylenediamine, butylenediamine, phenylenediamine, xylylenediamine, phenylenediethylamine or 3-methylamine phenylethylamine;

   The solvent is selected from one or more mixtures of cyclopentanol, ethylene glycol or ethylene glycol monoethyl ether.
9. An application of the water-based polyester modified silicone resin described in claims 1 to 8 in the preparation of low VOC hot water resistant silicone coatings.
10. The application according to claim 9, characterized in that: the water-based polyester modified silicone resin is mixed with water to form a self-emulsifying dispersion, or is acidified into a salt and then mixed with water to form a self-emulsifying dispersion;

    The obtained self-emulsifying dispersion is mixed with necessary cross-linking agents, pigments, fillers and functional additives to prepare low VOC hot water resistant silicone coating.
11. A preparation method of water-based polyester modified silicone resin according to claim 1, characterized in that the method includes the following steps:

    S1. In a catalyst and an inert atmosphere, the hydroxyl-terminated polyester and the organic silicone intermediate undergo a condensation reaction at 130 to 150°C to obtain polyester-modified silicone;

    The mass ratio of hydroxyl-terminated polyester to silicone intermediate is 0.5 to 2:1;

    S2. In an inert atmosphere, perform an esterification reaction between the polyester-modified silicone obtained by the condensation of S1 and p-hydroxybenzoic acid at 180-220°C to obtain compound A;

    The mass ratio of polyester modified silicone to p-hydroxybenzoic acid is 1:5~25;

    S3. Mix the compound A obtained in S2 with aldehyde and diamine evenly, and conduct Mannich reaction at 80-120°C in the presence of a solvent to obtain a water-based polyester-modified silicone resin with amine end groups;

    The mass ratio of compound A to aldehyde and diamine is m (compound A): m (aldehyde): m (diamine) = 100: 5 to 20: 5 to 20.
12. The preparation method according to claim 11, characterized in that:

    In S1, the mass ratio of hydroxyl-terminated polyester and silicone intermediate is 1:1~1.5.

    In S2, the mass ratio of polyester-modified silicone to p-hydroxybenzoic acid is 1:10-15;

    In S3, the mass ratio of compound A to aldehyde and diamine is m (compound A): m (aldehyde): m (diamine) = 100: 5 to 10: 5 to 10.
13. The preparation method according to claim 11, characterized in that: when the solvent in S3 is ethylene glycol monoethyl ether, in terms of mass ratio, m (compound A): m (ethylene glycol monoethyl ether) = 10: 1 ~ 4 .
14. The preparation method according to claim 11, characterized in that the synthesis of the hydroxyl-terminated polyester adopts the following method: polybasic acid and dihydric alcohol are reacted at 150-200°C for 0.5-1.5h, and then trihydric alcohol or tetrahydric alcohol is added. Alcohol, after continuing the reaction for 1 to 2 hours, the temperature is raised to 200 to 230°C and reacted for 2 to 3 hours. After dehydration and condensation, a multifunctional hydroxyl-terminated polyester is obtained.
15. The preparation method according to claim 14, characterized in that: the dihydric alcohol, trihydric alcohol or tetrahydric alcohol is selected from the group consisting of ethylene glycol, propylene glycol, glycerin, butylene glycol, butanetriol, neopentyl alcohol and One or a combination of diol, pentaerythritol, pentaerythritol, trimethylolpropane, trimethylolethane, benzenedimethanol, and benzenediethanol;

    The polybasic acid is selected from terephthalic acid, isophthalic acid, terephthalic acid, isophthalic acid, 2-methyl-1,4-phthalic acid, trimellitic anhydride, pyromellitic anhydride, 2,5-di One or a combination of methyl-1,4-phthalic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, and 1,4-cyclohexanedicarboxylic acid.

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