Oxetane vinyl ether and preparation method thereof

Abstract

The invention discloses oxetane vinyl ether, which has the following molecular formula: # imgabs0 #, wherein R1 is H or alkyl with the carbon atom number of 1-3, and R2 is H or alkyl with the carbon atom number of 1-2. According to the preparation method of the oxetane vinyl ether reactive diluent, the raw materials are simple, the reaction of monohydric alcohol and acetylene is carried out at lower pressure, the reaction is relatively safe, and the reaction has better selectivity and conversion rate. Compared with the traditional oxetane diluent, the oxetane vinyl ether disclosed by the invention has the advantages of low viscosity and high polymerization activity. The oxetane vinyl ether has a bifunctional curing structure, and vinyl ether functional groups can be subjected to cation curing and free radical curing, so that the oxetane vinyl ether can be used for cation curing, and the diluting property and the polymerization activity are improved; and dual curing can be carried out, and product application is enriched.

Description

Technical Field

[0001] The invention relates to the technical field of photocurable material synthesis, in particular to oxetane vinyl ether and a preparation method thereof. Background Art

[0002] Cationic light curing has the advantages of not being affected by oxygen inhibition, having a small volume shrinkage, and being able to cure after light exposure. Its application and research scope are becoming increasingly extensive. The diluents used in cationic curing mainly include vinyl ethers, epoxies, and oxygen heterocycles.

[0003] In recent years, oxetane reactive diluents have developed rapidly. These compounds have the characteristics of low viscosity, low curing shrinkage, high bonding strength, fast polymerization speed, low toxicity and low volatility, and are widely used in UV-curing materials. The main types are: monofunctional oxetane, difunctional oxetane, and hybrid oxetane.

[0004] At present, common oxetane cationic curing monomers on the market include: 3-ethyl-3-oxetane methanol, 3,3-(oxybismethylene)bis(3-ethyl)oxetane, 3-ethyl-3-[(benzyloxy)methyl]oxetane, etc. The above diluents have a single function and high viscosity, while the allyloxetane synthesized in Chinese patent CN104892549A and the methacrylate oxetane synthesized in Chinese patent CN110698437A have dual active functional groups, but they need to be cured secondary and have low activity. Summary of the invention

[0005] The object of the present invention is to provide an oxetane vinyl ether and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An oxetane vinyl ether, the molecular formula of which is as follows:

[0008]

[0009] Wherein R1 is H or an alkyl group having 1 to 3 carbon atoms, and R2 is H or an alkyl group having 1 to 2 carbon atoms.

[0010] A method for preparing oxetane vinyl ether, comprising the following steps:

[0011] (1) firstly adding an oxygen heterocyclic monohydric alcohol and a catalyst into a reactor, and removing light components under negative pressure at a temperature of 50-80° C. and a pressure of 100-200 Pa to prepare potassium alcoholate;

[0012] (2) then transferring the potassium alcoholate to a stainless steel high-pressure reactor, removing the air in the reactor, sealing the equipment, and heating to 70-130° C., continuously introducing acetylene gas into the reactor, and controlling the reaction pressure at 0.03-0.20 MPa;

[0013] (3) After the reaction is completed, the reaction materials in the reactor are subjected to vacuum distillation at a pressure below 1 kPa to obtain oxetane vinyl ether.

[0014] As a further embodiment of the present invention: the catalyst is one or more selected from potassium hydroxide, potassium methoxide, and potassium tert-butoxide.

[0015] As a further solution of the present invention: the amount of the catalyst is 0.05-1% of the mass of the oxygen heterocyclic monohydric alcohol.

[0016] As a further solution of the present invention: the amount of the catalyst is 0.3-0.7% of the mass of the oxygen heterocyclic monohydric alcohol.

[0017] As a further embodiment of the present invention: the molecular formula of the oxetane monohydric alcohol is as follows:

[0018]

[0019] As a further solution of the present invention: the conditions of the vacuum distillation in step (3) are: temperature of 80-180°C and pressure of less than 1KPa.

[0020] As a further solution of the present invention: the conditions of the vacuum distillation in step (3) are: temperature of 120-140°C and pressure of less than 0.8KPa.

[0021] Oxetane vinyl ether can be used as a cationic photocurable active diluent. Vinyl ether cationic diluents have the characteristics of low viscosity, low odor, high copolymerization activity, and strong dilution ability. For example, if oxetane is modified, that is, a vinyl ether group is introduced into oxetane monohydric alcohol, the resulting oxetane vinyl ether has the characteristics of low viscosity of vinyl ether and high activity of oxetane.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The method for preparing the oxetane vinyl ether active diluent of the present invention has simple raw materials, the reaction of monohydric alcohol and acetylene is carried out under relatively low pressure, which is relatively safe, and the reaction has good selectivity and conversion rate.

[0024] 2. Compared with traditional oxetane diluents, the oxetane vinyl ether of the present invention has the advantages of low viscosity and high polymerization activity.

[0025] 3. The oxetane vinyl ether of the present invention has a bifunctional curing structure, and the vinyl ether functional group can be used for both cationic curing and free radical curing. Therefore, the present invention can be used for cationic curing to improve dilution and polymerization activity; it can also be used for dual curing to enrich product applications. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] 300g of 3-ethyloxetane methanol and 2.1g of potassium hydroxide were placed in a glass flask, stirred evenly and heated to 70°C, gradually evacuated to a pressure of 100Pa for dehydration for 1h, and then the material was transferred to a stainless steel autoclave, the equipment was sealed, and then replaced with nitrogen, and then replaced with acetylene three times, and then the temperature was raised and heated. When the material was heated to 120°C, acetylene gas was introduced, and the reaction temperature was controlled at 130°C and the reaction pressure was controlled at 0.01MPa. The reaction was for 5h. After the reaction was completed, the temperature was lowered to below 80°C and replaced with nitrogen twice to normal pressure. The material was discharged to obtain crude oxetane vinyl ether I. Its composition is shown in Table 1.

[0029] The crude product I was subjected to vacuum distillation at 130° C. and 700 Pa to obtain pure oxetane vinyl ether with a purity of 99.6%.

[0030] Example 2

[0031] 300g of 3-methyloxetane methanol and 0.9g of potassium methoxide were placed in a glass flask, stirred evenly and heated to 60°C, gradually evacuated to a pressure of 150Pa to remove methanol for 30min, and then the material was transferred to a stainless steel autoclave, the equipment was sealed, and then nitrogen was replaced, and then replaced with acetylene three times, and then the temperature was raised and heated. When the material was heated to 110°C, acetylene gas was introduced, and the reaction temperature was controlled at about 120°C and the reaction pressure was 0.015MPa. The reaction was 5h. After the reaction was completed, the temperature was lowered to below 80°C and replaced with nitrogen twice to normal pressure. Discharge to obtain crude oxetane vinyl ether II. Its composition is shown in Table 1.

[0032] The crude product II was subjected to vacuum distillation at 120°C and 600Pa to obtain pure oxetane vinyl ether with a purity of 99.4%.

[0033] Example 3

[0034] 400g 3-hydroxyethyl oxetane and 2.4g potassium tert-butoxide were placed in a glass flask, stirred evenly and heated to 80°C, gradually evacuated to a pressure of 200Pa to remove tert-butanol for 2h, and then the material was transferred to a stainless steel autoclave, the equipment was sealed, and then nitrogen was replaced, and then replaced with acetylene three times, and then the temperature was raised and heated. When the material was heated to 100°C, acetylene gas was introduced, and the reaction temperature was controlled at about 110°C and the reaction pressure was 0.02MPa. The reaction was for 5h. After the reaction was completed, the temperature was lowered to below 80°C and replaced with nitrogen twice to normal pressure. Discharge to obtain crude oxetane vinyl ether III. Its composition is shown in Table 1.

[0035] The crude product III was subjected to vacuum distillation at 130°C and 500Pa to obtain pure oxetane vinyl ether with a purity of 99.3%.

[0036] Example 4

[0037] 300g of 3-ethyloxetane methanol and 3g of potassium tert-butoxide were placed in a glass flask, stirred evenly and heated to 80°C, gradually evacuated to a pressure of 180Pa to remove tert-butanol for 1.5h, and then the material was transferred to a stainless steel autoclave, the equipment was sealed, and then nitrogen was replaced, and then replaced with acetylene three times, and then the temperature was raised and heated. When the material was heated to 110°C, acetylene gas was introduced, and the reaction temperature was controlled at about 120°C and the reaction pressure was 0.0172MPa. The reaction was for 5h. After the reaction was completed, the temperature was lowered to below 80°C and replaced with nitrogen twice to normal pressure. Discharge to obtain crude oxetane vinyl ether IV. Its composition is shown in Table 1.

[0038] The crude product IV was subjected to vacuum distillation at 120°C and 500 Pa to obtain pure oxetane vinyl ether with a purity of 99.5%.

[0039] Example 5

[0040] 300g of 3-methyloxetane methanol and 2.1g of potassium methoxide were placed in a glass flask, stirred evenly and heated to 60°C, gradually evacuated to a pressure of 110Pa to remove methanol for 1h, and then the material was transferred to a stainless steel autoclave, the equipment was sealed, and then replaced with nitrogen and then replaced with acetylene three times, the purpose of which was to completely replace the nitrogen in the autoclave, and then the temperature was raised and heated. When the material was heated to 90°C, acetylene gas was introduced, and the reaction temperature was controlled at about 100°C and the reaction pressure was controlled at 0.011MPa. The reaction was for 5h. After the reaction was completed, the temperature was lowered to below 80°C and replaced with nitrogen twice to normal pressure. The material was discharged to obtain crude oxetane vinyl ether V. Its composition is shown in Table 1.

[0041] The crude product V was subjected to vacuum distillation at 130°C and 700Pa to obtain pure oxetane vinyl ether with a purity of 99.4%.

[0042] Table 1 Composition of materials after reaction

[0043] materials raw material% Finished product% Other impurities% Crude product I 66.3 33.4 0.3 Crude product II 68.1 31.7 0.2 Crude product III 62.8 36.8 0.4 Crude IV 67.5 32.2 0.3 Crude V 69.1 30.7 0.2

[0044] It can be seen from Table 1 that the oxetane vinyl ether prepared by the preparation method of the present invention has good selectivity and yield.

[0045] Table 2 Physical and chemical properties of several oxygen heterocyclic active diluents

[0046]

[0047] As can be seen from Table 2, the viscosity of the active diluent of the present invention is much lower than that of 3-ethyl-3-oxetane methanol in Comparative Example and 3,3-(oxybismethylene)bis(3-ethyl)oxetane in Comparative Example 2, and the odor is significantly lower than that of methacrylate oxetane in Comparative Example 3. Therefore, the oxetane vinyl ether of the present invention has good application prospects and effects.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An oxetane vinyl ether, characterized in that Its molecular formula is as follows: Wherein R1 is H or an alkyl group having 1 to 3 carbon atoms, and R2 is H or an alkyl group having 1 to 2 carbon atoms.

2. A method for preparing oxetane vinyl ether as claimed in claim 1, characterized in that: The specific steps are as follows: (1) firstly adding an oxygen heterocyclic monohydric alcohol and a catalyst into a reactor, and removing light components under negative pressure at a temperature of 50-80° C. and a pressure of 100-200 Pa to prepare potassium alcoholate; (2) then transferring the potassium alcoholate to a stainless steel high-pressure reactor, removing the air in the reactor, sealing the equipment, and heating to 70-130° C., continuously introducing acetylene gas into the reactor, and controlling the reaction pressure at 0.03-0.20 MPa; (3) After the reaction is completed, the reaction materials in the reactor are subjected to vacuum distillation at a pressure below 1 kPa to obtain oxetane vinyl ether.

3. The preparation method of oxetane vinyl ether according to claim 2, characterized in that, The catalyst is one or more selected from potassium hydroxide, potassium methoxide, and potassium tert-butoxide.

4. The method for preparing oxetane vinyl ether according to claim 2 or 3, characterized in that: The amount of the catalyst used is 0.05-1% of the mass of the oxygen heterocyclic monohydric alcohol.

5. The method for preparing oxetane vinyl ether according to claim 4, wherein The amount of the catalyst used is 0.3-0.7% of the mass of the oxygen heterocyclic monohydric alcohol.

6. The method for preparing oxetane vinyl ether according to claim 5, characterized in that: The molecular formula of the oxetane monohydric alcohol is as follows:

7. The method for preparing oxetane vinyl ether according to claim 6, characterized in that: The conditions of the vacuum distillation in step (3) are: temperature of 80-180° C. and pressure of less than 1 KPa.

8. The method for preparing oxetane vinyl ether according to claim 7, characterized in that: The conditions of the vacuum distillation in step (3) are: temperature of 120-140° C. and pressure of less than 0.8 KPa.

9. An oxetane vinyl ether as claimed in claim 1 or 2 used as a cationic photocurable reactive diluent.

Images