Disubstituted benzophenone compound, preparation thereof and application of disubstituted benzophenone compound in optical radiation curing

Abstract

The invention relates to the field of radiation curing, and provides a disubstituted benzophenone compound, the structural general formula of which is as shown in the formula I: # imgabs0 #, in the formula I, X is any one of F, Cl and methoxyl groups. The invention also provides a preparation method of the disubstituted benzophenone compound, and also provides an optical radiation curing composition, an optical radiation curing material formula system and application. The disubstituted benzophenone compound has the advantages that the disubstituted benzophenone compound is an environment-friendly, non-toxic and efficient photoinitiator, the problems that volatile toxic small-molecule organic compounds escape in the reaction, or pungent smell is generated, or physiological toxicity is caused by compound migration and the like are solved, and the disubstituted benzophenone compound is suitable for industrial production. Meanwhile, the photopolymerization activity is high, the anti-yellowing effect is good, the solubility is good, and the preparation cost is low.

Description

Technical Field

[0001] The present invention relates to the field of radiation curing, and particularly to a disubstituted benzophenone compound, a preparation method thereof, and an application thereof in photo-radiation curing. Background Art

[0002] In ultraviolet (UV) radiation-curable materials, benzophenone, monosubstituted benzophenone compounds, and macromolecular benzophenone compounds have been used as free radical photoinitiators for systems containing olefinically unsaturated compounds. And BP, PBZ, CBP, OMBB, etc. with the following structural formulas are all current successful industrial examples:

[0003]

[0004] However, during the polymerization reaction process, these photoinitiators will produce environmentally unfriendly residual odors, and their slow release is also toxic to human health. Therefore, in addition to the photosensitivity, yellowing resistance, cost performance, and solubility of the photoinitiator itself, the odor and health pollution caused by the photoinitiator itself have also begun to become the focus of increasing attention in the field of radiation curing.

[0005] In view of this, numerous studies have been dedicated to developing new compounds to solve the above problems. The most representative ones are macromolecular BP and 1212, and their structural formulas are as follows:

[0006]

[0007] These research results reflect an urgent and strong development demand in the field of radiation curing, that is, to create low-odor products, and focus on reducing and even eliminating the inherent disadvantages of traditional commercially available photoinitiators in polymerization applications, such as the toxicity of the photoinitiator itself and the unpleasant odor remaining after packaging the finished product.

[0008] However, from the perspective of people's livelihood and environmental protection applications, the research and development of new photoinitiators face double challenges. It is necessary to overcome the above problems and provide new green and environmentally friendly compounds, and at the same time ensure that these new compounds have economic cost competitiveness and comprehensive performance competitiveness. For example, although the macromolecular BP product solves the problem of volatile organic compounds (VOCs), it has caused new problems. Its photo-polymerization activity has been greatly reduced, only 1 / 3 of that of BP, and at the same time the cost has also increased significantly; although 1212 overcomes the odor problem, it performs poorly in terms of yellowing resistance and solubility, which brings obstacles to industrial applications. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a disubstituted benzophenone compound, its preparation and application in photo-radiation curing. The disubstituted benzophenone compound of the present invention is an environmentally friendly, non-toxic and highly efficient photoinitiator, which avoids problems such as the escape of volatile toxic small-molecule organic compounds during the reaction, the generation of pungent odors, or the physiological toxicity caused by compound migration. At the same time, it has the advantages of high photo-polymerization activity, good yellowing resistance, good solubility and low preparation cost.

[0010] The present invention adopts the following technical solutions to solve the above technical problems:

[0011] A disubstituted benzophenone compound, the general structural formula of which is shown in Formula I:

[0012]

[0013] In Formula I, X is any one of F, Cl, and methoxy groups.

[0014] As one of the preferred embodiments of the present invention, the compounds shown in Formula II, Formula III, Formula IV, Formula V, Formula VI, Formula VII, Formula VIII, Formula IX, Formula X, Formula XI, Formula XII or Formula XIII are specifically selected:

[0015]

[0016] A preparation method of the above disubstituted benzophenone compound, which is prepared by a Friedel-Crafts acylation reaction catalyzed by a Lewis acid using benzoyl chloride and disubstituted benzene as raw materials.

[0017] A photo-radiation curing composition, comprising at least one polymerizable ethylenically unsaturated compound and the above disubstituted benzophenone compound.

[0018] As one of the preferred embodiments of the present invention, the polymerizable ethylenically unsaturated compound is at least one of acrylic monomers and resins containing acrylic structures.

[0019] As one of the preferred embodiments of the present invention, based on the total amount of 100 parts by weight of the photo-radiation curing composition, the usage amount of the disubstituted benzophenone compound as a photoinitiator is 0.01 - 20 parts, more preferably 0.5 - 10 parts, and most preferably 4 parts.

[0020] A photo-radiation curing material formulation system, comprising at least one ethylenically unsaturated compound and any one of the following Composition 1 and Composition 2:

[0021] Composition 1: Comprising at least one disubstituted benzophenone compound or a mixture thereof;

[0022] Composition 2: comprising at least one disubstituted benzophenone compound or a mixture with other types of photoinitiators;

[0023] The di-substituted benzophenone compounds in the composition 1 and the composition 2 are the above-mentioned di-substituted benzophenone compounds.

[0024] As one of the preferred embodiments of the present invention, the polymerizable ethylenically unsaturated compound is at least one of an acrylic acid monomer and a resin containing an acrylic acid structure.

[0025] As one of the preferred embodiments of the present invention, the other types of photoinitiators are one or more of BP, CBP, macromolecular BP, OMBB, and PBZ photoinitiators.

[0026] An application of the above-mentioned light radiation curing composition or light radiation curing material formula system in wood furniture paint, plastic product coating, and printing and packaging ink.

[0027] The advantages of the present invention compared to the prior art are:

[0028] (1) The disubstituted benzophenone compound provided by the present invention is an environmentally friendly, non-toxic, and highly efficient photoinitiator, which avoids the problems of escaping volatile toxic small molecule organic compounds, generating pungent odors, or causing physiological toxicity due to compound migration during the reaction;

[0029] (2) The present invention uses cheap and readily available industrial-grade raw materials as a starting point to prepare disubstituted benzophenone compounds, and uses the compounds as photoinitiators for radiation curing, which is committed to solving the toxicity and VOCs pollution problems of the photoinitiator itself and can also improve its economic competitiveness;

[0030] (3) Compared with commercially available photoinitiators, the disubstituted benzophenone compounds of the present invention also have excellent photopolymerization activity, yellowing resistance and solubility advantages, further improving their use efficiency and product stability in the application field. DETAILED DESCRIPTION

[0031] The following is a detailed description of the embodiments of the present invention. The embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments. At the same time, the experimental methods used in the following embodiments are conventional methods unless otherwise specified; the materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified.

[0032] Example 1. Preparation of disubstituted benzophenone compounds A-1, A-2, and A-3:

[0033]

[0034] Under nitrogen protection, 140 g of benzoyl chloride and 1.5 L of dichloroethane were added to a reagent bottle, and stirring was started and the temperature was lowered. 145 g of aluminum trichloride was added to the reaction kettle in batches, and stirring and temperature reduction were maintained for 1 h. Then, 130 g of 2-chlorotoluene was dropped into the reaction kettle over 3 h, and the temperature of the kettle was maintained below 5 °C. After the dropping was completed, the temperature was maintained below 10 °C, and stirring was continued for 6 h to obtain 231 g of crude product A001 of the mixture. By HPLC, in the crude product A001 of the mixture, compound A-1 was 78%, compound A-2 was 15%, compound A-3 was 5%, and A-4 was 2%. Finally, 210 g of the final product A002 was obtained by recrystallization of ethanol under temperature control, in which the total content of compound A-1 and compound A-2 was 98%.

[0035] Example 2. Preparation of disubstituted benzophenone compounds B-1, B-2, and B-3:

[0036]

[0037] Under nitrogen protection, 140 g of benzoyl chloride and 1.5 L of dichloroethane were added to a reagent bottle, and stirring was started and the temperature was lowered. 145 g of aluminum trichloride was added to the reaction kettle in batches, and stirring and temperature reduction were maintained for 1 h. Then, 125 g of 2-methoxytoluene was dropped into the reaction kettle over 3 h, and the temperature of the kettle was maintained below 5 °C. After the dropping was completed, the temperature was maintained below 10 °C and stirring was continued for 6 h to obtain 227 g of crude product B001 of the mixture. By HPLC, in the crude product B001 of the mixture, compound B-1 was 82%, compound B-2 was 15%, compound B-3 was 2%, and compound B-4 was 1%. Finally, 215 g of the final product B002 was obtained by recrystallization, in which the total content of compound B-1 and B-2 was 98.5%.

[0038] Example 3. Performance test:

[0039] I. Test method

[0040] In this example, by formulating an exemplary photo-radiation curable composition, various application performances of the disubstituted benzophenone compound shown in formula I of the present invention as a photoinitiator were tested, including aspects such as curing rate, odor, yellowing resistance effect, solubility, etc.

[0041] 1. Preparation of the photo-radiation curable composition

[0042] The formulation of the photo-radiation curable composition is shown in Table 1. In Table 1, the photoinitiator is one of the bis-substituted benzophenone photoinitiators represented by Formula I disclosed in the present invention (A-1, A-2, A-3, A-4, A002, B-1, B-2, B-3, B-4, B002 in Examples 1 and 2) or the commercially available photoinitiators known in the prior art (BP, CBP, macromolecular BP, OMBB, PBZ, for comparison). The corresponding photo-radiation curable compositions were prepared respectively according to Table 1.

[0043] Table 1 Formulation of Photo-Radiation Curable Composition

[0044]

[0045] 2. Curing Rate

[0046] The above-prepared photo-radiation curable compositions were respectively coated on glass slides using a 22 μm wire bar coater to compare the performance of commercially available photoinitiators and the compounds of Examples 1 and 2 of the present invention as photoinitiators.

[0047] Specifically, the coated samples were mounted on a belt and the samples were conveyed under a medium-pressure mercury lamp. Taking that no imprint was produced when scratched repeatedly with a fingernail as the complete curing standard, the belt speed of the completely cured samples was determined.

[0048] 3. Odor Grade

[0049] After the photo-radiation curable compositions were completely cured according to the above curing method, the residual odor test was carried out.

[0050] Specifically, 5 people independently evaluated the odor level, and the standard was "≥3 people had similar or unified evaluations of the odor level".

[0051] The evaluation criteria are represented by numbers as follows:

[0052] Grade A: No odor can be felt;

[0053] Grade B: A very slight odor;

[0054] Grade C: A slight odor;

[0055] Grade D: An obvious odor;

[0056] Grade E: A strong odor;

[0057] Grade F: A very strong odor.

[0058] 4. Yellowing Resistance Test

[0059] The yellowing resistance was measured for ΔE data using a color difference meter.

[0060] 5. Solubility and Dissolution Rate Test

[0061] Taking the active diluents HDDA (1,6 - hexanediol diacrylate) and TMPTA, which are widely used in this field, as diluents for comparison, the dissolution properties of the photoinitiator of the present invention and commercially available photoinitiators were tested and compared. Specifically, at 25 °C, the maximum weight that can be dissolved in 100 g of solvent was used as the evaluation criterion.

[0062] The test conditions for the dissolution rate were as follows: at 25 °C, the stirring speed was 120 rpm, and the time required for the test photoinitiator with a mass ratio of 5% to be completely dissolved and clarified in HDDA (1,6 - hexanediol diacrylate).

[0063] II. Test Results

[0064] The test results of the curing rate, odor level, and yellowing resistance are shown in Table 2, and the test results of the solubility and dissolution rate are shown in Table 3.

[0065] Table 2 Test Results of Curing Rate, Odor Level, and Yellowing Resistance

[0066] Example Curing speed m / min Odor level Yellowing resistance (ΔE) Example A-1 98 A-B 0.12 Example A-2 98 A-B 0.11 Example A-3 78 A-B 0.12 Example A-4 75 A-B 0.13 Example A002 98 A-B 0.11 Example B-1 99 A-B 0.15 Example B-2 98 A-B 0.16 Example B-3 72 A-B 0.14 Example B-4 71 A-B 0.15 Example B002 99 A-B 0.15 BP 72 D 0.19 CBP 98 C-D 0.13 Macromolecular BP 25 A-B 0.18 OMBB 45 A-B 0.12 PBZ 115 A-B 0.42

[0067] It can be seen from the results in Table 2 that the photo - radiation curing composition containing the bis - substituted benzophenone photoinitiator shown in Formula I of the present invention has good photo - initiating activity, yellowing resistance, and low odor emission; its comprehensive effect is generally better than that of currently commercially available photoinitiators, especially the effects of A - 1, A - 2 and B - 1, B - 2.

[0068] Table 3 Test Results of Solubility and Dissolution Rate

[0069] Photoinitiator HDDA (g / 100g) TMPTA (g / 100g) Dissolution rate (min) A-1 14 12 2 A-2 15 11 2 A-3 14 11 3 A-4 13 10 4 A002 ＞15 ＞15 ＜2 B-1 12 11 3 B-2 13 11 3 B-3 10 10 4 B-4 11 10 5 B002 ＞15 14 2 BP ＞15 ＞15 ＜2 CBP 10 8 7 Macromolecular BP - - - OMBB 9 8 7 PBZ 9 7 6

[0070] It can be seen from Table 3 that compared with commercially available photoinitiators, the bis - substituted benzophenone photoinitiator of the present invention has obvious advantages in solubility. Especially in the case of using A002 and B002, it will also slightly increase the solubility, and the use of small - molecule active diluents and solvents can be greatly reduced during use.

[0071] In summary, the bis-substituted benzophenone compounds of the present invention are environmentally friendly, non-toxic, and highly efficient photoinitiators, which avoid problems such as the escape of volatile toxic small-molecule organic compounds during the reaction, the generation of pungent odors, or the physiological toxicity caused by compound migration. At the same time, they have the advantages of high photo-polymerization activity, good yellowing resistance, good solubility, and low preparation cost. Using the compounds of the present invention as photoinitiators to prepare photo-radiation curable compositions (polymerizable olefinically unsaturated compounds + bis-substituted benzophenone compounds of the present invention) or photo-radiation curable material formulation systems (bis-substituted benzophenone compounds of the present invention or their mixtures / bis-substituted benzophenone compounds or mixtures with other types of photoinitiators + olefinically unsaturated compounds) can be effectively applied to fields such as wood furniture paints, plastic product coatings, printing and packaging inks, etc.

[0072] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A disubstituted benzophenone compound, characterized in that: Its general structural formula is shown in Formula I: In formula I, X is any one of F, Cl, and methoxy group.

2. The disubstituted benzophenone compound according to claim 1, characterized in that: Specifically select the compound represented by the following formula II, formula III, formula IV, formula V, formula VI, formula VII, formula VIII, formula IX, formula X, formula XI, formula XII or formula XIII:

3. A method for preparing a disubstituted benzophenone compound as claimed in claim 1 or 2, characterized in that: It is prepared by Friedel-Crafts acylation catalyzed by Lewis acid using benzoyl chloride and disubstituted benzene as raw materials.

4. A photo-curable composition, characterized in that: The invention comprises at least one polymerizable ethylenically unsaturated compound and the di-substituted benzophenone compound according to claim 1 or 2.

5. The photocurable composition according to claim 4, characterized in that: The polymerizable ethylenically unsaturated compound is at least one of an acrylic acid monomer and a resin containing an acrylic acid structure.

6. The photocurable composition according to claim 4, characterized in that: Based on 100 parts by weight of the total amount of the light radiation curable composition, the disubstituted benzophenone compound is used as a photoinitiator in an amount of 0.01 to 20 parts.

7. A light radiation curing material formulation system, characterized in that: It comprises at least one ethylenically unsaturated compound and any one of the following composition 1 and composition 2: Composition 1: comprising at least one disubstituted benzophenone compound or a mixture thereof; Composition 2: comprising at least one disubstituted benzophenone compound or a mixture with other types of photoinitiators; The disubstituted benzophenone compound in the composition 1 and the composition 2 is the disubstituted benzophenone compound according to claim 1 or 2.

8. The light radiation curing material formulation system according to claim 7, characterized in that: The polymerizable ethylenically unsaturated compound is at least one of an acrylic acid monomer and a resin containing an acrylic acid structure.

9. The light radiation curing material formulation system according to claim 7, characterized in that: The other types of photoinitiators are one or more of BP, CBP, macromolecular BP, OMBB, and PBZ photoinitiators.

10. Use of the photo-curable composition according to any one of claims 4 to 6, or the photo-curable material formulation system according to any one of claims 7 to 9, in wood furniture paint, plastic product coating, and printing and packaging ink.

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