阅读说明：本技术 一种酰化法制备大分子光引发剂的方法及其应用 (Method for preparing macromolecular photoinitiator by acylation method and application thereof ) 是由 蔡龙 陈寿生 刘华东 罗先平 于 2020-11-23 设计创作，主要内容包括：本发明属于涂料化工技术领域,具体涉及一种酰化法制备大分子光引发剂的方法及其应用,制备方法为,冰浴环境中,在催化剂的作用下,二元醇与二酰基化合物反应得到预聚物；在冰浴条件下,将已溶于溶剂中的1173或者184引发剂缓慢滴加到上述预聚物中,氮气环境反应；将上述反应产物反沉淀在溶剂中,将得到的产物重复洗涤3次,干燥,得到最终产物。本发明所提供的大分子光引发剂与现用的小分子引发剂引发活性相当,在固化涂层中迁移率低,而且挥发性低,气味小,漆膜高度透明,避免了小分子引发剂可导致的毒性、气味等问题,同时具有很好的溶解性,不会造成任何光引发困难；固化后的漆膜透明性高,耐黄性好,适合于木器家具涂装等领域。(The invention belongs to the technical field of coating chemical industry, and particularly relates to a method for preparing a macromolecular photoinitiator by an acylation method and application thereof, wherein the preparation method comprises the steps of reacting dihydric alcohol and a diacyl compound under the action of a catalyst in an ice bath environment to obtain a prepolymer; under the ice bath condition, slowly dripping 1173 or 184 initiator dissolved in solvent into the prepolymer, and reacting in nitrogen environment; and (3) performing anti-precipitation on the reaction product in a solvent, repeatedly washing the obtained product for 3 times, and drying to obtain the final product. The macromolecular photoinitiator provided by the invention has the initiating activity equivalent to that of the conventional micromolecular initiator, has low mobility in a cured coating, low volatility and small smell, is highly transparent, avoids the problems of toxicity, smell and the like caused by the micromolecular initiator, has good solubility and cannot cause any photoinitiation difficulty; the cured paint film has high transparency and good yellowing resistance, and is suitable for the fields of wood furniture coating and the like.)

1. A method for preparing a macromolecular photoinitiator by an acylation method is characterized by comprising the following preparation steps:

(1) dissolving a binary alcohol in a solvent, slowly dropwise adding a diacyl compound with a slightly excessive molar ratio in an ice bath environment, then adding a catalyst, removing the ice bath after dropwise adding is finished, and reacting for 4-48 hours in a nitrogen environment at 5-50 ℃ to obtain a prepolymer;

(2) slowly dripping 1173 or 184 initiator dissolved in solvent into the prepolymer under the ice bath condition, and reacting for 4-48 h under the nitrogen environment at the temperature of 10-50 ℃;

(3) and (3) performing anti-precipitation on the reaction product in the step (2) in a solvent, repeatedly washing and drying the obtained product to obtain the final product.

2. The method according to claim 1, wherein the glycol in step (1) comprises:

C_nH_2n+2O₂wherein n is within the range of 2-10, the hydroxyl position is not limited, and the diol structure with the terminal group at the preferred position is optimized;

or/and, HOCH₂(CH₂OCH₂)_nCH₂The polymerization degree of the OH polyethylene glycol is more than or equal to 1 and less than or equal to 10;

or/and, H (OCHCH)₃CH₂)_nThe polymerization degree of the OH polypropylene glycol is more than or equal to 2 and less than or equal to 10.

3. The method according to claim 1, wherein the diacyl compound structure of step (1) comprises:

C_nH_2n-4O₂Cl₂，C_nH_2n-4O₂Br₂wherein n is more than or equal to 2 and less than or equal to 12, the position of the diacyl is not limited, and the diacyl structure with the position at the terminal group is preferred;

or/and, aromatic diacyl compounds;

or/and, a cycloaliphatic diacyl compound.

4. The method according to claim 1, wherein the catalyst in step (1) comprises 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU), 1, 5-diazabicyclo [4.3.0] non-5-ene (DBN), Triethylamine (TEA), 4-Dimethylaminopyridine (DMAP), pyridine (Py), dibutyltin dilaurate, 1, 3-bis (2,4, 6-trimethylphenyl) -4, 5-dihydroimidazol-2-ylidene, 1, 3-di-t-butylimidazol-2-ylidene, triethylenediamine; the molar weight ratio of the catalyst used to the molar weight of the diol is 0.01 to 10%.

5. The method according to claim 1, wherein the reaction temperature in the step (1) is 20-30 ℃, and the reaction time is 6-12 h; the reaction temperature in the step (2) is 20-30 ℃, and the reaction time is 6-12 h.

6. The method of claim 1, wherein the solvent used in the reaction comprises ethyl acetate, butyl acetate, acetonitrile, DMF, DMSO, toluene, xylene.

7. The method according to claim 1, wherein the solvent used in step (3) comprises petroleum ether or diethyl ether.

8. A macromolecular photoinitiator obtained by the preparation method of any one of claims 1 to 7, characterized in that the structure of the macromolecular photoinitiator is as follows:

1173 type polyester initiator:

type 184 polyester initiator:

wherein R is₁Is a main structure of a diacyl radical; r₂The polyether polyol is dihydric alcohol, and the dihydric alcohol comprises micromolecular dihydric alcohol and polyether polyol with the molecular weight of 500-5000.

9. Use of a macromolecular photoinitiator according to claim 8 in coatings.

Technical Field

The invention belongs to the technical field of coating chemical industry, and particularly relates to a method for preparing a macromolecular photoinitiator by an acylation method and application thereof.

Background

The UV photocuring technology means that under the action of ultraviolet light, an initiator in a system generates active free radicals, so that double bonds or epoxy groups are initiated to polymerize, and finally a solid high-molecular paint film is formed. As a green technology, UV photocuring has the characteristics of high efficiency, economy, energy conservation, environmental friendliness and wide adaptability. The UV initiator is the key for generating polymerization, active free radicals can be excited by ultraviolet irradiation so as to promote cross-linking and film forming among molecules, and the action principles of the photoinitiator are different and can be divided into two types: the first type is a cleavage type photoinitiator, and currently, the mainstream used initiators include 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), 1-hydroxycyclohexyl phenyl ketone (184), and deep-cured 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide (TPO), phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide (819); the second type is hydrogen abstraction type photoinitiator, and the main used includes Benzophenone (BP), methyl o-benzoylbenzoate (OMBB), 4-Chlorobenzophenone (CPB), 4-Phenylbenzophenone (PBZ) and the like.

Most of the second kind of initiators have the defects of easy sublimation, low curing speed and the like, while the first kind of initiators have more kinds, and the initiators with different structures can endow the properties of odor elimination, yellow resistance, high initiation efficiency, deep curing and the like, but have the defects of volatilization, toxicity, high molecular mobility and the like due to small molecular weight, so that the application range of the initiators is limited.

Disclosure of Invention

The invention aims to solve the problems in the prior art, provides a macromolecular photoinitiator, and provides a method for preparing the macromolecular photoinitiator by an acylation method and application thereof.

The technical scheme of the invention is as follows:

the invention discloses a method for preparing a macromolecular photoinitiator by an acylation method and application thereof, wherein a diacyl compound and a dihydric alcohol reagent react to obtain a prepolymer with a product end group of diacyl, and then the prepolymer is continuously reacted with a photoinitiator containing hydroxyl 2-hydroxy-2-methyl-1-phenyl-1-acetone (1173) or 1-hydroxycyclohexyl phenyl ketone (184) to prepare the macromolecular photoinitiator which can be used in paint.

A method for preparing a macromolecular photoinitiator by an acylation method comprises the following preparation steps:

(1) firstly, dissolving a binary alcohol in a solvent, slowly dripping a diacyl compound with a slightly excessive molar ratio in an ice bath environment, wherein the diacyl compound is dissolved in the solvent in advance; then adding a catalyst, removing the ice bath after dropwise adding is finished, and reacting for 4-48 h in a nitrogen environment at the temperature of 5-50 ℃ to obtain a prepolymer;

(2) then, placing the prepolymer obtained in the step (1) in an ice bath condition, dissolving 1173 or 184 initiator in the solution, slowly dripping the solution into the prepolymer, and reacting for 4-48 h in a nitrogen environment at the temperature of 10-50 ℃;

(3) finally, the product of step (2) is reprecipitated in a solvent, and the obtained product is washed 3 times and dried repeatedly to obtain the final product.

Further, the dihydric alcohol in the step (1) comprises:

C_nH_2n+2O₂wherein n is within the range of 2-10, the hydroxyl position is not limited, and the diol structure with the terminal group at the preferred position is optimized;

or/and, HOCH₂(CH₂OCH₂)_nCH₂The polymerization degree of the OH polyethylene glycol is more than or equal to 1 and less than or equal to 10;

or/and, H (OCHCH)₃CH₂)_nOH PolypropyleneThe polymerization degree of the alcohol is more than or equal to 2 and less than or equal to 10.

Further, the diacyl compound structure in step (1) includes:

C_nH_2n-4O₂Cl₂，C_nH_2n-4O₂Br₂wherein n is more than or equal to 2 and less than or equal to 12, the position of the diacyl is not limited, and the diacyl structure with the position at the terminal group is preferred;

and/or, aromatic diacyl compounds:

wherein R is Cl or Br;

or/and, a cycloaliphatic diacyl compound:

wherein R is Cl or Br.

Further, the 1173 or 184 initiator used in the step (2) has the following structure:

further, the catalyst in the step (1) comprises 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU), 1, 5-diazabicyclo [4.3.0] non-5-ene (DBN), Triethylamine (TEA), 4-Dimethylaminopyridine (DMAP), pyridine (Py), dibutyltin dilaurate, 1, 3-bis (2,4, 6-trimethylphenyl) -4, 5-dihydroimidazol-2-ylidene, 1, 3-di-tert-butylimidazol-2-ylidene, triethylenediamine; the molar weight ratio of the catalyst used to the molar weight of the diol is 0.01 to 10%.

Further, the reaction temperature in the step (1) is preferably 20-30 ℃, and the reaction time is preferably 6-12 h; in the step (2), the preferable reaction temperature is 20-30 ℃, and the preferable reaction time is 6-12 h.

Further, the solvents used in step (1) and step (2) include, but are not limited to: ethyl acetate, butyl acetate, acetonitrile, DMF, DMSO, toluene, xylene.

Further, the anti-solvent used in the step (3) is not particularly limited as long as it can precipitate the target macromolecule, and petroleum ether and diethyl ether are preferred.

The macromolecular photoinitiator prepared by the preparation method has the following structure:

1173 type polyester initiator:

type 184 polyester initiator:

wherein R is₁Is a main structure of a diacyl radical; r₂The polyether polyol is dihydric alcohol, and the dihydric alcohol comprises micromolecular dihydric alcohol and polyether polyol with the molecular weight of 500-5000.

The application of the macromolecular photoinitiator in coating.

The invention has the beneficial effects that:

the macromolecular photoinitiator provided by the invention has the initiating activity equivalent to that of the conventional micromolecular initiator, has low mobility in a cured coating, low volatility and small smell, is highly transparent, avoids the problems of toxicity, smell and the like caused by the micromolecular initiator, has good solubility and cannot cause any photoinitiation difficulty; the cured paint film has high transparency and good yellowing resistance, and is suitable for the fields of wood furniture coating and the like.

The 1173 polyester type initiator and the 184 polyester type initiator prepared by the invention can effectively avoid pungent odor caused by micromolecule 1173 and 184 initiators in the polymerization process, can effectively reduce generated micromolecule benzaldehyde substances, and meanwhile, the paint film is highly transparent, has excellent yellowing resistance, is not greatly influenced in polymerization activity, and can still maintain high polymerization activity; the macroinitiator has excellent comprehensive performance and great application value.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

For further understanding of the present invention, the present invention will be further described with reference to examples.

Example 1

The preparation method of 1173 type polyester initiator comprises the following steps:

firstly, dissolving 1 mole fraction of polyglycol (n is 4) in 50mL of ethyl acetate, dissolving 1.1 mole amount of terephthaloyl chloride compound in 100mL of ethyl acetate solution under the ice bath environment, then slowly dropwise adding, subsequently adding 5% mole fraction of DMAP catalyst, removing the ice bath after dropwise adding is finished, and reacting for 12 hours under the nitrogen environment at 40 ℃ to obtain a prepolymer;

then, putting the prepolymer in an ice bath condition, dissolving 1.1 mol of 1173 initiator in 30mL of ethyl acetate solution, slowly dripping the solution into the prepolymer, and reacting for 12 hours at 40 ℃ in a nitrogen environment;

finally, the above reaction product was reprecipitated in 500mL of diethyl ether, and the resulting product was washed 3 times repeatedly and dried to obtain the final product.

The final product was a white solid in 79.3% yield.

Example 2

The preparation method of the 184 type polyester initiator comprises the following steps:

firstly, dissolving 1 mole fraction of polypropylene polyol (n-4) in 50mL of butyl acetate, dissolving 1.1 mole amount of terephthaloyl chloride compound in 50mL of butyl acetate solution under the ice bath environment, slowly dropwise adding, then adding 10% mole fraction of DMAP catalyst, removing the ice bath after dropwise adding is finished, and reacting for 8 hours under the nitrogen environment at 50 ℃ to obtain a prepolymer;

then, putting the prepolymer in an ice bath condition, dissolving 1.1 molar mass of 184 initiator in 50mL of butyl acetate solution, slowly and dropwise adding the solution into the prepolymer, and reacting for 8 hours at 50 ℃ in a nitrogen environment;

finally, the above reaction product was back precipitated in 1000mL of ether solvent, and the resulting product was washed 3 times and dried to obtain the final product.

The final product was a white solid in 86.8% yield.

Example 3

The prepared macromolecular photoinitiator, 1173 type polyester initiator, is applied to the coating, and in the specific embodiment, the coating comprises the following components in percentage by mass:

25% of epoxy acrylate, 30% of polyester acrylate (Kotian chemical 2202), 0.3% of a flatting agent (BYK358N), 0.2% of a defoaming agent (Tego920), 1% of a dispersing agent (BYK2009), 20% of powder, 5% of 1173 type polyester macroinitiator and 18.5% of monomer dipropylene glycol diacrylate (DPGDA).

The coating prepared by the formula of the components is sprayed on the surface of the wood of the fraxinus mandshurica according to a mechanical spraying method, and the production efficiency can be greatly improved through the rapid curing of ultraviolet light, and the performance test results are shown in table 1.

Example 4

The prepared macromolecular photoinitiator, 1173 type polyester initiator, is applied to the coating, and in the specific embodiment, the coating comprises the following components in percentage by mass:

25% of epoxy acrylate (Sanmu chemical SM6105-80), 30% of polyurethane acrylate (Changxing chemical 61438), 0.3% of flatting agent (BYK358N), 0.2% of defoaming agent (Tego920), 1% of dispersing agent (BYK2009), 20% of powder, 5% of 1173 type polyester macroinitiator and 18.5% of monomer dipropylene glycol diacrylate (DPGDA).

The coating prepared by the formula is sprayed on the surface of the fraxinus mandshurica wood according to a mechanical spraying method, and is rapidly cured by ultraviolet light, so that the production efficiency can be greatly improved, and the performance test result is shown in table 1.

Example 5

The prepared macromolecular photoinitiator, 1173 type polyester initiator, is applied to the coating, and in the specific embodiment, the coating comprises the following components in percentage by mass:

25% of polyester acrylate (Koxta chemical 2202), 30% of polyurethane acrylate (Changxing chemical 61438), 0.3% of flatting agent (BYK358N), 0.2% of defoaming agent (Tego920), 1% of dispersing agent (BYK2009), 20% of powder, 5% of 1173 type polyester macroinitiator and 18.5% of monomer tripropylene glycol diacrylate (TPGDA).

The coating prepared by the formula is sprayed on the surface of the fraxinus mandshurica wood according to a mechanical spraying method, and is rapidly cured by ultraviolet light, so that the production efficiency can be greatly improved, and the performance test result is shown in table 1.

Example 6

The prepared macromolecular photoinitiator, 184 type polyester initiator, was applied to the coating, and in this specific example, the coating composition was, in terms of mass percent:

25% of polyester acrylate (Koxta chemical 2202), 30% of polyurethane acrylate (Changxing chemical 61438), 0.3% of flatting agent (BYK358N), 0.2% of defoaming agent (Tego920), 1% of dispersing agent (BYK2009), 20% of powder, 5% of 184 type polyester macroinitiator and 18.5% of monomer tripropylene glycol diacrylate (TPGDA).

The coating prepared by the formula is sprayed on the surface of the fraxinus mandshurica wood according to a vacuum spraying method, and is rapidly cured by ultraviolet light, so that the production efficiency can be greatly improved, and the performance test result is shown in table 1.

Table 1 results of performance testing of the coatings provided in examples 3-6 after spray curing

Test examples

In order to fully prove the comprehensive performance of the macromolecular photoinitiator provided by the invention, in the experimental example, the macromolecular photoinitiator prepared by the invention is compared with the existing micromolecular initiator by formula application tests, and the method comprises the following specific steps:

TABLE 2 coating compositions and dosage ratios of different initiators

The paint formulations in table 2 above were tested for performance, and compared with the odor, yellowing resistance, initiation activity, volatility, and compatibility, and the results are shown in table 3 below:

table 3 comparative testing results

Performance index	Scheme 1	Scheme 2	Scheme 3	Scheme 4	Scheme 5
						Smell(s)	Smell clearing	Smell clearing	Pungent odor	Pungent odor	Has little smell
Yellowing resistance	High resistance to yellow	High resistance to yellow	Resistant to yellow	Resistant to yellow	Easy yellowing
						Initiation Activity	High activity	High activity	High activity	High activity	High activity
Volatility	Is difficult to volatilize	Is difficult to volatilize	Volatile	Volatile	Volatile
						Compatibility	Is easy to dissolve	Is easy to dissolve	Are highly compatible	Is easy to dissolve	Is easy to dissolve

From the above performance tests, it can be seen that the 1173 polyester initiator and the 184 polyester initiator prepared by the present invention can effectively avoid the irritating odor caused by the small molecule 1173 and 184 initiator during the polymerization process, and simultaneously, compared with the benzophenone initiator, the present invention has the advantages of excellent yellowing resistance, high transparency of the paint film and high polymerization activity. The tests show that the macromolecular photoinitiator prepared by the invention has excellent comprehensive performance and high application value.

Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the present invention. Any modification, equivalent replacement, or modification made within the spirit and principle of the present invention should be included in the protection scope of the present invention.