A method for preparing a vinyl epoxy resin

Abstract

The present application relates to a kind of preparation of vinyl epoxy resin, mainly through intermediate in structural formula II, then by controlling reaction conditions, the selective esterification alkane link primary alcohol, the target product is obtained by retaining the secondary alcohol on cyclohexane ring;The preparation process provided can obtain high-purity vinyl epoxy resin, and the performance is significantly better than commercially available product.

Description

Technical Field

[0001] This invention relates to the field of vinyl epoxy resin preparation technology, and more particularly to a method for preparing vinyl epoxy resin. Background Technology

[0002] Vinyl epoxy resin is currently the most widely used and consumed photocurable oligomer. Its photocuring speed is the fastest among various oligomers, and the cured coating exhibits high hardness, good gloss, excellent corrosion resistance, heat resistance, and electrochemical properties. However, it also has drawbacks, such as insufficient flexibility and high brittleness of the cured film. Therefore, to meet the needs of different fields, vinyl modification of epoxy resin has become one of the research hotspots in this field.

[0003] 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate has attracted widespread attention as an excellent epoxy compound (Formula III).

[0004] Currently, the widely used method is to directly prepare epoxy ring-opening, as reported in patent CN106221642, which directly uses formula (Ⅲ) and HEA (Formula IV) to react. Because the structure of formula (Ⅲ) is easy to self-polymerize, the product obtained by this method has large polymerization, and the irritating HEA is difficult to remove completely, and the performance is deviated.

[0005] (Formula IV);

[0006] No reports have been found of structural (II) intermediates. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing a vinyl epoxy resin with excellent performance and no irritating odor.

[0008] To solve the above-mentioned technical problems, the technical solution of the present invention is: a method for preparing vinyl epoxy resin, the innovation of which is as follows: the specific preparation method is as follows:

[0009] First, an intermediate with structural formula II is prepared, and then selectively esterified to obtain a vinyl epoxy resin with structural formula I; wherein, structural formula II is:

[0010] ;

[0011] ;

[0012] ;

[0013] ;

[0014] Where n represents a natural number from 2 to 8;

[0015] Structural formula I is:

[0016] ;

[0017] ;

[0018] ;

[0019] ;

[0020] R1 is selected from -CH3 or H, and n is a natural number from 2 to 8.

[0021] Furthermore, the intermediate of structural formula II is prepared by reacting structural formula III, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate, with the corresponding diol in the presence of a catalyst; structural formula III is:

[0022] .

[0023] Furthermore, the selective esterification reaction is carried out at a temperature of 50-70°C.

[0024] Furthermore, the selective esterification reaction is carried out at a temperature of 55-60°C.

[0025] Furthermore, the catalyst is one or more of p-toluenesulfonic acid, concentrated sulfuric acid, acidic cation exchange resin, etc.

[0026] Furthermore, the catalyst is p-toluenesulfonic acid.

[0027] The advantages of this invention are:

[0028] 1) In this invention, the primary alcohol linked by the structure II is mainly obtained by selectively esterifying the primary alcohol of the alkane by controlling the reaction conditions, while retaining the secondary alcohol on the cyclohexane ring, to obtain the target product; the preparation process provided can obtain high-purity vinyl epoxy resin with significantly better performance than commercially available products. Attached Figure Description

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 This is a flowchart of a method for preparing a vinyl epoxy resin according to the present invention. Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. Example

[0033] like Figure 1 As shown: 25.2 g of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 62.1 g of ethylene glycol, and 0.1 g of boron trifluoride tetrahydrofuran complex were added to a three-necked flask, stirred, and heated to 50±5℃. The reaction was maintained at this temperature for 5 h. Excess ethylene glycol was removed under reduced pressure to obtain 35.1 g of compound II, with a yield of 93.4%.

[0034] Add 30g of compound of structural formula II, 11.5g of acrylic acid, 2g of acidic cation exchange resin and 60g of toluene to a reaction flask, reduce pressure to -0.075Mpa, reflux at 55℃ for 4h to remove water, cool down, filter to remove acidic cation exchange resin, and remove toluene from the filtrate under reduced pressure to obtain product of structural formula I.

[0035] Resin Review:

[0036] Curing formula: 95% resin + 5% photoinitiator 1173 + appropriate amount of defoamer and leveling agent, film thickness 20μm.

[0037] Light source: LED 365nm, 255mW / cm² 2 .

[0038] Yellowing resistance: 340nm, 0.89 W / cm 2 60℃.

[0039] ;

[0040] As can be seen from the table above, the pencil hardness, adhesion, gloss and yellowing resistance of the vinyl epoxy resin prepared according to the present invention are all superior to those of conventional commercially available vinyl epoxy resins to varying degrees.

[0041] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a vinyl epoxy resin, characterized in that: The specific preparation method is as follows: First, an intermediate with structural formula II is obtained, and then selectively esterified to obtain a vinyl epoxy resin with structural formula I; wherein, structural formula II is, Where n represents a natural number from 2 to 8; Structural form I is, R1 is selected from -CH3 or H, and n is a natural number from 2 to 8. The intermediate of structural formula II is prepared by reacting structural formula III, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarbamate, with the corresponding diol in the presence of a catalyst; structural formula III is: The selective esterification reaction is carried out at a temperature of 50-70°C; the catalyst for the selective esterification reaction is one or more of p-toluenesulfonic acid, concentrated sulfuric acid, and acidic cation exchange resin.

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