CN113150244B - Sulfonate type epoxy acrylate resin and preparation method and application thereof - Google Patents

Abstract

The invention discloses a sulfonate type epoxy acrylate resin and a preparation method and application thereof. The sulfonate type epoxy acrylate resin of the present invention has the structure shown in formula (I): wherein R ₁ is one or more of the following structures:

R ₂ is H or CH ₃ ; n is a positive integer of 1-3. The sulfonate type epoxy acrylate resin of the present invention introduces a sulfonate structure. Since the sulfonate group is a strong hydrophilic group, the hydrophilic properties of the epoxy acrylate resin are greatly improved; Compared with the ammonium salt system, the odor is lower, and it does not bring toxic and harmful gases during the synthesis process. The water-based light-curing coating prepared by mixing the sulfonate type epoxy acrylate resin with a photoinitiator and water can be rapidly cured under ultraviolet light conditions, and the water contact angle of the cured coating is less than or equal to 65°.

Description

A kind of sulfonate type epoxy acrylate resin and its preparation method and application

technical field

The invention relates to the technical field of polymer material synthesis, and more particularly, to a sulfonate type epoxy acrylate resin and a preparation method and application thereof.

Background technique

Epoxy resin is widely used in construction, electronic appliances, coatings, adhesives and other fields because of its good adhesion to substrates, good chemical resistance, and high heat resistance and electrical insulation. However, because the traditional epoxy resin is oily, its segment itself does not introduce a hydrophilic group or the introduced hydrophilic group is not very hydrophilic. Usually, it is necessary to add an emulsifier or a salt-forming agent later to enhance its water solubility.

Chinese patent application CN101914171A discloses a sulfonic acid-type UV-curable water-based epoxy emulsion, which utilizes the reaction of epoxy fumaric acid chloride and sulfamic acid to introduce sulfonic acid groups into both ends of the molecular chain to obtain UV-curable water-based epoxy emulsion. Hydrogen chloride gas will be generated during the reaction process. In order to avoid the escape of harmful gas, it is also necessary to add alkali into the system for absorption. Chinese patent application CN111961169A discloses an aqueous epoxy resin emulsion, including epoxy resin, emulsifier and water, which improves the hydrophilicity and emulsification of the epoxy resin. However, the external emulsifier often needs strong mechanical stirring to make the epoxy resin evenly dispersed.

Therefore, it is necessary to develop an epoxy acrylate resin with good hydrophilicity.

SUMMARY OF THE INVENTION

In order to overcome the defect of poor hydrophilicity described in the prior art, the present invention provides a sulfonate type epoxy acrylate resin, and the acid salt type epoxy acrylate resin introduces a sulfonate salt with strong hydrophilicity The structure greatly improves the hydrophilic properties of epoxy acrylate resin.

Another object of the present invention is to provide a method for preparing the above-mentioned sulfonate type epoxy acrylate resin.

Another object of the present invention is to provide the application of the above-mentioned sulfonate type epoxy acrylate resin in the preparation of water-based photocurable coatings.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A sulfonate type epoxy acrylate resin having the structure shown in formula (I):

Wherein R ₁ is one or more of the following structures:

R ₂ is H or CH ₃ ; n is a positive integer of 1-3.

The sulfonate type epoxy acrylate resin of the present invention introduces a sulfonate structure. Since the sulfonate group is a strong hydrophilic group, the hydrophilic property of the epoxy acrylate resin is greatly improved; Compared with the ammonium salt system, the odor is lower, and the odor residue problem of epoxy resin is avoided.

为链状结构，相较于

的环状结构，在树脂乳化时具有链状结构的分子链更容易发生构象转变从而具有更好的水溶性。R ₁ in the sulfonate type epoxy acrylate resin is a chain and a cyclic conformation, which can improve the water solubility of the resin and the hardness of the resin; wherein

is a chain structure, compared to

When the resin is emulsified, the molecular chain with a chain-like structure is more likely to undergo conformational transformation and thus have better water solubility.

Preferably, the R ₁ is

The present invention also protects the preparation method of the above-mentioned sulfonate type epoxy acrylate resin, comprising the following steps:

S1. After mixing the sulfonate diol and the acid anhydride compound, heating to 100-105°C under stirring for 1 hour, and monitoring the acid value of the reaction solution;

S2. Theoretical acid value is calculated according to the molar ratio of the reactants. When the titration acid value reaches the theoretical value, add epoxy resin and catalyst to the reaction solution in S1, and react at 110～112°C until the acid value is less than 5mgKOH /g;

S3. To the reaction solution in S2, add the end-capping monomer dissolved with the polymerization inhibitor, and react at 115-118° C. until the acid value is less than 5 mgKOH/g to obtain the sulfonate type epoxy acrylic resin.

The preparation method of the present invention uses sulfonate diol and acid anhydride compounds as raw materials to introduce sulfonate groups, and no toxic and harmful gas such as hydrogen chloride is brought in the synthesis process.

In the steps of S1, S2, and S3, as the reaction progresses, the molecular weight of the reactants increases, the intermolecular entanglement increases, and the effective collision probability decreases; therefore, the reaction temperature increases in a gradient to increase the effective intermolecular The probability of collision, promotes the degree of reaction to be more complete.

However, the reaction temperature in S1-S3 is also not easy to be too high, and an excessively high reaction temperature will cause the polymerization of the end-capping monomer to generate gel. Therefore, the reaction temperature of 100-105°C in S1, 110-112°C in S2, and 115-118°C in S3 was set in a gradient manner.

Preferably, the molecular weight of the sulfonate diol is 500-1000.

Generally speaking, sulfonate diols with smaller molecular weights have a larger proportion of hydrophilic segments, and as the molecular weight increases, the proportion of hydrophobic segments increases, so the water-soluble sulfonate diols with smaller molecular weights Sex is better.

Preferably, the water content of the sulfonate diol is <0.1%.

Preferably, the acid anhydride compound is one or more of succinic anhydride, phthalic anhydride or hexahydrophthalic anhydride.

Preferably, the epoxy resin is a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin.

The epoxy equivalent of the bisphenol A epoxy resin is 190, and the epoxy equivalent of the bisphenol F epoxy resin is 170.

Preferably, the catalyst is triphenylphosphine and/or triethylbenzylammonium chloride.

Preferably, the polymerization inhibitor is one or more of tert-butyl hydroquinone, parahydroxyanisole (MEHQ), and 2-methoxyhydroquinone.

The addition of a polymerization inhibitor can prevent the polymerization of end-capping monomers at high temperatures.

Preferably, the end-capping monomer is acrylic acid and/or methacrylic acid.

Preferably, the mass ratio of the sulfonate diol, acid anhydride compound, epoxy resin, catalyst, polymerization inhibitor and end-capped acrylic acid is (25-38):(5-8):(28-40) : (0.3 to 0.5): (0.05 to 0.08): (5 to 8).

The sulfonate type epoxy acrylate resin can be dispersed in water.

The present invention also protects the application of the above-mentioned sulfonate type epoxy acrylate resin in the preparation of water-based photocurable coatings.

Preferably, the water-based photocurable coating comprises the following components by weight:

70-80 parts of sulfonate type epoxy acrylate resin, 1.5-3 parts of photoinitiator, and 20-30 parts of water.

The photoinitiator may be a photoinitiator commonly used in photocurable coatings.

Optionally, the photoinitiator is TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), TPOL (2,4,6-trimethylbenzoylphenylphosphonic acid) ethyl ester), 1173 (2-hydroxy-2-methyl-1-phenylacetone).

Compared with the prior art, the beneficial effects of the present invention are:

(1) In the sulfonate type epoxy acrylate resin of the present invention, a sulfonate structure is introduced, and since the sulfonate group is a strong hydrophilic group, the hydrophilic property of the epoxy acrylate resin is greatly improved, and No toxic and harmful gases will be brought in the synthesis process.

(2) The water-based photocurable coating obtained by mixing the sulfonate type epoxy acrylate resin of the present invention with a photoinitiator and water can be rapidly cured under ultraviolet light conditions, and the cured coating water contact angle is less than or equal to 65° .

Description of drawings

Figure 1 shows the appearance of the epoxy acrylate resins prepared in Examples 1-2 and Comparative Example 1.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments.

The raw materials in the examples and comparative examples can be obtained commercially;

Among them, sulfonate diol, the moisture content is less than 0.1%, purchased from Beijing Baiyuan Chemical Co., Ltd., BY3306 (500 molecular weight), BY3303 (1000 molecular weight), BY3305B (2000 molecular weight);

Polyester diol, molecular weight 500, obtained by esterification and dehydration of methyl propylene glycol and succinate.

Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Example 1

The present embodiment provides a sulfonate type epoxy acrylate resin, and the preparation method is as follows:

S1. After mixing sulfonate diol (BY3306, molecular weight 500) and succinic anhydride, heat to 100-105°C under stirring for 1 hour, and monitor the acid value of the reaction solution;

S2. When the acid value of the reaction solution reaches 160mgKOH/g, add bisphenol A epoxy resin (epoxy equivalent of 190) and catalyst triphenylphosphine to the reaction solution in S1, and react at 110～112°C To acid value <5mgKOH/g;

S3. Add acrylic acid dissolved with polymerization inhibitor (p-hydroxyanisole) to the reaction solution in S2, and react to acid value <5mgKOH/g under 115～118°C to obtain the sulfonate type epoxy resin Acrylic resin;

The mass ratio of sulfonate diol (BY3306), succinic anhydride, bisphenol A epoxy resin, catalyst, polymerization inhibitor and acrylic acid is 24.81:9.93:37.71:0.3:0.08:7.15.

The prepared sulfonate type epoxy acrylate resin structural formula is as follows:

Example 2

This embodiment provides a sulfonate type epoxy acrylate resin. The difference between the preparation method and the embodiment 1 is that the sulfonate diol used is BY3303, with a molecular weight of 1000;

The mass ratio of sulfonate diol (BY3303), succinic anhydride, bisphenol A epoxy resin, catalyst, polymerization inhibitor and acrylic acid is 37.83:7.57:28.75:0.3:0.08:5.45.

Example 3

This embodiment provides a sulfonate type epoxy acrylate resin. The difference between the preparation method and the embodiment 1 is that methacrylic acid is used instead of acrylic acid in equimolar.

Example 4

This embodiment provides a sulfonate type epoxy acrylate resin. The difference between the preparation method and the embodiment 2 is that hexahydrophthalic anhydride is used instead of succinic anhydride; bisphenol F type epoxy resin (epoxy equivalent: 170) is used. Instead of bisphenol A epoxy resin;

The mass ratio of sulfonate diol (BY3303), hexahydrophthalic anhydride, bisphenol F-type epoxy resin, catalyst, polymerization inhibitor and acrylic acid is 37.33:11.51:25.38:0.3:0.08:5.38.

Example 5

This embodiment provides a sulfonate type epoxy acrylate resin, and the difference between the preparation method and the embodiment 1 is that phthalic anhydride is used instead of succinic anhydride in an equimolar ratio.

Comparative Example 1

This comparison provides a sulfonate type epoxy acrylate resin, the difference between the preparation method and Example 1 is that the sulfonate diol used is BY3305B, 2000 molecular weight.

Comparative Example 2

This comparative example provides an epoxy acrylate resin, and the difference between the preparation method and Example 1 is that a polyester diol with a molecular weight of 500 is used instead of the sulfonate diol.

Comparative Example 3

This comparative example provides an epoxy acrylate resin. The difference between the preparation method and Example 1 is that a polytetrahydrofuran diol with a molecular weight of 500 is used instead of the sulfonate diol.

Performance Testing

Use the epoxy acrylate resin that above-mentioned embodiment and comparative example make respectively to prepare water-based photocurable coating, and preparation method is as follows:

80 parts of epoxy acrylate resin, 20 parts of water or dipropylene glycol triacrylate, and 1.5 parts of photoinitiator TPO are mixed uniformly to obtain a water-based photocurable coating.

The water-based photocurable coating is scraped on a glass plate with a four-sided film applicator, with a thickness of 20 μm, and is irradiated with a UV mercury lamp at a wavelength of 365 nm for 1-3 s to cure into a coating film.

The performance test of the coating films is carried out respectively, and the specific methods are as follows:

Water Contact Angle: Tested according to GB/T 30693-2014.

Coating water absorption: tested according to HG/T 3344-2012.

The test results of Examples 1-5 and Comparative Examples 1-3 are shown in Table 1.

Table 1 Test results of Examples 1-5 and Comparative Examples 1-3

water contact angle coating water absorption Example 1 57.7 11.87% Example 2 62.9 6.13% Example 3 55.3 9.03% Example 4 60.4 7.45% Example 5 56.8 9.67% Comparative Example 1 73.8 5.38% Comparative Example 2 95.7 3.1% Comparative Example 3 90.2 3.56%

According to the test results in Table 1, it can be seen that the water-based photocurable coatings prepared from the epoxy acrylate resins of Examples 1 to 5, after curing into a film, the water contact angle of the coating film is all ≤65°, indicating that the coating has Good hydrophilic properties. The water resistance of water-based photocurable coatings with good hydrophilicity is generally poor, but in some occasions, the coating is required to have a certain water resistance, and the water absorption rate is not easy to be too high. In each embodiment of the present invention, the water absorption rate of the coating prepared by the water-based light-curing coating is all less than or equal to 15%, that is, the hydrophilicity and water resistance of the epoxy acrylate resin are well balanced. In Comparative Example 1, the molecular weight of the sulfonate diol is 2000, and the water contact angle of the epoxy acrylate resin is 73.8°, and the hydrophilicity is slightly poor. In Comparative Example 2 and Comparative Example 3, no sulfonic acid group was introduced, and the smearing water contact angles of the prepared epoxy acrylate resins all exceeded 90°, and their hydrophilicity was poor.

The appearances of the epoxy acrylate resins prepared in Examples 1-2 and Comparative Example 1 are shown in FIG. 1 . It can be seen that the appearance of the resin prepared by the sulfonate diol with a molecular weight of 500 is transparent, indicating that its water solubility is good; the appearance of the resin prepared by the sulfonate diol with a molecular weight of 1000 is opaque and fluid Better emulsion; the appearance of resin prepared by sulfonate diol with molecular weight 2000 is thicker emulsion. The appearance state is consistent with the water contact angle test results in Table 1, indicating that as the molecular weight of the sulfonate diol increases, the proportion of its hydrophilic segment decreases, which makes the water solubility of the resin decrease and the hydrophilicity is poor. .

Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the embodiments of the present invention. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (9)

1. A sulfonate type epoxy acrylate resin is characterized by having a structure shown as a formula (I):

wherein R is₁Is one or more of the following structures:

R₂is H or CH₃(ii) a n is a positive integer of 1-3.

2. The sulfonate type epoxy acrylate resin according to claim 1 wherein R is₁Is composed of

3. The method for producing a sulfonate type epoxy acrylate resin according to claim 1 or 2, comprising the steps of:

s1, mixing sulfonate dihydric alcohol and an anhydride compound, heating to 100-105 ℃ under a stirring condition, reacting for 1h, and monitoring the acid value of a reaction solution; the molecular weight of the sulfonate dihydric alcohol is 500-1000;

s2, when the acid value reaches a theoretical value, adding epoxy resin and a catalyst into the reaction liquid in S1, and reacting at 110-112 ℃ until the acid value is less than 5 mgKOH/g;

s3, adding blocked acrylic acid dissolved with a polymerization inhibitor into the reaction liquid in the S2, and reacting at the temperature of 115-118 ℃ until the acid value is less than 5mgKOH/g to obtain the sulfonate type epoxy acrylate resin.

4. The method according to claim 3, wherein the water content of the sulfonate diol is less than 0.1%.

5. The preparation method according to claim 3, wherein the acid anhydride compound is one or more of succinic anhydride, phthalic anhydride or hexahydrophthalic anhydride.

6. The method according to claim 3, wherein the epoxy resin is a bisphenol A type epoxy resin and/or a bisphenol F type epoxy resin.

7. The preparation method according to claim 3, wherein the polymerization inhibitor is one or more of tert-butyl hydroquinone, p-hydroxyanisole or 2-methoxyhydroquinone.

8. The preparation method according to claim 3, wherein the mass ratio of the sulfonate diol, the anhydride compound, the epoxy resin, the catalyst, the polymerization inhibitor and the blocked acrylic acid is (25-55) to (5-12) to (18-40) to (0.3-0.5) to (0.05-0.08) to (3-8).

9. Use of the sulfonate type epoxy acrylate resin according to claim 1 or 2 for the preparation of an aqueous photocurable coating.

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