WO2008019527A1

WO2008019527A1 - Phenyl benzophenone derivates and uses as photoinitiators

Info

Publication number: WO2008019527A1
Application number: PCT/CN2006/002001
Authority: WO
Inventors: Wenchao Zhao; Lili Jiang; Yonglin Wang; Qingjin Yan; Peng Luo; Shidian Han; Lixiu Yao; Junfeng Shao
Original assignee: Insight High Technology Co., Ltd.
Priority date: 2006-08-08
Filing date: 2006-08-08
Publication date: 2008-02-21

Abstract

Compounds of formula (I) and uses as photoinitiators, where in: A is O, G is H, x=1; or G is a residue of a polyhydroxy compound, the number of hydroxy groups of said polyhydroxy compound is N, and 2 ≤ N ≤ 6; x is an integer, and 2 ≤ x ≤ N; A represents independently each other a group of formula -[O(CHR2CHR1)a]y-, -[O(CH2)bCO]y-, or -[O(CH2)bCO](y-1)-[O(CHR2CHR1)a]- where in one of R1 and R2 is hydrogen and the other is hydrogen, methyl or ethyl; a is 1 or 2; b is 4 or 5; y is an integer from 1 to 10.

Description

Phenylbenzophenone derivatives and their use as photoinitiators

The present invention relates to a class of macromolecularized phenylbenzophenone derivatives. The derivative can be used as a photoinitiator, particularly a varnish for printing light, a printing ink or the like. The invention also provides radiation curable compositions comprising at least one of the compounds of the invention as a photoinitiator. Background technique

Photoinitiators for varnish formulations require good cure speeds, especially good surface cure activity, low odor, low yellowness, and good solubility. In addition, as consumers become increasingly sensitive to the contamination of foreign compounds in food, the tendency to migrate compounds and dissolve in external media should be as small as possible in order to comply with future legislative requirements. At present, it is increasingly difficult to meet the above requirements in the commercial products.

Currently, benzophenone is still the most widely used photoinitiator for ultraviolet (UV) cured overprint varnishes because of its good surface cure, high solubility, and low cost, and easy availability. However, benzophenone has a strong odor and is extremely easy to migrate from the print and dissolve into the food.

It is well known that macromoleized diphenyl fluorenone derivatives and polyfunctional benzophenone derivatives can be made into products with low odor, which are not prone to migration and dissolution, but these products have the disadvantage of low active ingredient content, and This in turn leads to a lower curing speed.

It can be seen that the cured coating with high functionality, good solubility in the coating formulation, high reactivity, and extremely low odor, migration and dissolution tendency is much lower than most existing benzophenone compounds. There is a real need for photoinitiators.

We have now discovered a class of compounds of the invention that meet the above requirements. The polyfunctional nature of this class of compounds allows it to maintain a relatively high functionality per gram, and its macromolecular core group gives it a very high solubility in UV curable formulations. The unit weight reactivity of the photoinitiator is extremely important in UV curing. If a photoinitiator is less reactive than benzophenone, the amount can be increased to maintain the cure speed of the formulation, but the effect is limited. In addition, after the concentration exceeds 10 to 12%, the non-acrylate functional material or the physical shield exhibiting a plasticizer, or the crosslink density of the cured film is lowered, thereby affecting the mechanical properties. The compound of the present invention not only overcomes the above-mentioned defects of benzophenone and other existing photoinitiators, but also has the advantages of extremely low odor, high solubility in ultraviolet curing formulations, migration and tendency to be dissolved by an external medium, and, in some cases, In case, its unit weight The amount of reactivity is almost equivalent to benzophenone itself, and in most cases, its reactivity is higher than that of the commonly used benzophenone substitute. Summary of the invention

The present invention provides a compound represented by the formula (I),

among them,

A is 0, G is H, = 1;

Or,

G is a residue of a polyhydroxy compound, the number of hydroxyl groups in the polyhydroxy compound is N, and 2 < N < 6;

X is an integer, JL2<x<N;

A independent generation

-+O(CH ₂ ) _b CO3⁄4T or

among them:

One of the groups R ¹ and R ² represents a hydrogen atom; the other group represents a hydrogen atom, a methyl group or an ethyl group;

a is 1 or 2j

b is 4 or 5;

y is an integer from 1 to 10.

In view of convenience and economy, a plurality of compounds conforming to the formula (I) are often mixed in practice. Accordingly, the present invention also provides a composition characterized in that the composition is composed of two or more compounds of the formula (I) in any ratio.

The invention also provides a photoinitiator comprising at least one compound of formula (I). In addition, the invention also provides the use of a compound of formula (I) as a photoinitiator.

Further, the present invention provides an energy curable liquid composition having the following composition:

A polymerizable component comprising at least one ethylenically unsaturated monomer or oligomer; a photoinitiator of the invention.

The present invention also provides that the energy-curing liquid composition of the present invention is placed under irradiation, in particular It is a method of preparing a cured polymer under ultraviolet radiation. detailed description

For the sake of convenience, the formula of the present invention (the IM compound is represented by G-(A-C0CH ₂ 0- PBZ) _x (PBZ represents phenyldibenzophenone); and (-C0CH ₂ 0- PBZ) _X is The portion of the compound is represented by G-(A-) _X and is referred to as the core of the compound.

In the compound of the formula (I) of the present invention, the oxygen atom attached to the phenyl group of the phenylbenzophenone may be attached to any position of the phenyl group. In view of the availability of the starting materials and the convenience of synthesis, it is preferred that the oxygen atom is attached to the ortho or para position relative to the benzophenone. The difference in the position of the attachment has no substantial effect on the nature of the compound, especially as a photoinitiator.

In the compound of the formula (I) of the present invention, it is preferred that A represents a group of the formula -f 0(0^ 111 ¹ )&^ ₇ ; more preferably A represents -fOCH ₂ C3⁄43⁄4r, "fOC3⁄4CH ₂ CH ₂ C3⁄4 or

- OCH(CH ₃ )CH ₂ 3⁄4r; A can also be ~ O(CH ₂ ) _b CO3⁄4r or

卄OCCH^CO^^fOCCH^CHR ¹ )^".

In the compound of the formula (I) of the present invention, since X may be greater than or equal to 2, a plurality of -A- groups are present in this case, and these groups are independent of each other, that is, they may be the same or different, wherein a The values of b, y may also be the same or different.

The core G-(A-) _x groups of the compounds of the invention have a significant effect on the properties of the compounds. According to the definition of the compound of the formula (I) according to the invention, the G- group contains one or more polyether and/or polyester segments of low degree of polymerization, which makes the compound tend to be liquid and contributes to its Dissolved in the coating formulation. Compounds that are structurally similar but do not contain the above polyether and/or polyester segments are often unusable because they are solid and/or insoluble in the coating composition. However, the molecular weight of the core G-(A-) _x should not be too high, generally not more than 1200, preferably not more than 800, and the excessively high molecular weight makes the photoinitiator content per unit weight too low.

Preferably, G is a residue of ethylene glycol, propylene glycol, butylene glycol, glycerol, trimethylolpropane, bistrihydroxydecylpropane, pentaerythritol or mepentaerythritol.

In the present specification, "a residue of a polyhydroxy compound" or "a residue of an alcohol" means a group remaining after a polyhydroxy compound or one or more hydroxyl groups in an alcohol loses a hydrogen atom. For example, the residue of CH ₂ OHCH ₂ 0H is CH ₂ 0HCH ₂ 0- or -0CH ₂ CH ₂ 0-. In the polyhydroxy compound or alcohol, other functional groups may be contained in addition to the hydroxyl group as long as these functional groups do not substantially adversely affect the synthesis or use of the compound of the present invention. When x is less than the number of hydroxyl groups contained in the polyhydroxy compound G, the compound of the present invention contains a free hydroxyl group. These free hydroxyl groups may be esterified as needed, or when the compounds of the invention are prepared in the presence of an acid. The nature of the ester thus obtained is not particularly limited, but is preferably a lower molecular weight fatty acid ester such as a C ₂ - C ₆ chain sulphate. Examples of such esters include acetates, propionates, butyrates and valerates.

When testing the compounds of the present invention prepared in the following examples, the numbers &, b and y in the above formula may not be integers, since in the preparation of the compounds, when the raw materials used are not In the case of a single compound, the product obtained is a mixture of several compounds of the formula (I). Of course, a, b and y are integers for each individual molecule of the product, and a single compound can also be isolated separately, and it will be understood by those skilled in the art that a single material can be used to make a single Compounds, but in practice, a mixture of these compounds is often used.

The compounds of the present invention can be prepared by well-known methods for preparing such compounds, and the exact synthetic route and reaction conditions selected will depend on the compound to be prepared.

For example, the compound of the present invention can be obtained by benzotylation of o-phenylphenoxyacetic acid represented by formula (II) or p-phenylphenoxyacetic acid represented by formula (( )) (1-1) or (1- 2), which is then prepared by esterification with a core compound of the formula (IV), wherein A, X and G in the core compound are as described above.

(HA) The _X -G (IV) reaction is preferably carried out in the presence of a solvent, and the nature of the solvent is not critical to the invention. The key is located as long as it has no adverse effect on the reagent or reaction. Suitable solvents include: alkanes such as cyclohexane and the like; aromatic hydrocarbons such as benzene, 'nonylbenzene or xylene.

It is preferably carried out in the presence of an acidic catalyst such as a sulfonic acid (for example with formic acid or methanesulfonic acid), a mineral acid (for example sulfuric acid, hydrochloric acid or polyphosphoric acid) or a Lewis acid (for example boron trifluoride or an organic titanate). .

The reaction temperature can be varied within a relatively wide range depending on the conditions of the reaction and the nature of the reagents and the solvent, as long as the temperature is high enough to remove water generated during the reaction to ensure completion of the reaction. We have found that it is usually most convenient to carry out the reaction at temperatures close to the reflux temperature of the reaction mixture. The time required for the reaction varies widely depending on the reaction temperature. Under the above optimum conditions, it usually takes only 2 to 20 hours to react.

After the completion of the reaction, it may be subjected to a post-treatment by a usual method, for example, washing the mixture with water and/or alkali water, drying, and then evaporating the solvent under reduced pressure to give a product.

The compounds of the invention are particularly suitable for use as photoinitiators, for example as photoinitiators in photocurable varnishes or inks. However, they can also act as photoinitiators in many other energy curable liquid compositions.

The energy curable compositions employing the compounds of the present invention typically comprise at least one radiation curable monomer and/or oligomer, a compound of the invention, and optionally a reactive diluent. In the case of printing inks, the composition also includes a colorant, i.e., a pigment. The radiation curable monomer or oligomer is preferably an ethylenically unsaturated compound, typically an acrylate oligomer or an acrylate monomer. Suitable acrylate oligomers include: aliphatic or aromatic acrylate phthalates, polyether acrylates, polyester acrylates and epoxidized propionates (e.g., bisphenol A epoxy acrylate). Suitable acrylate monomers include: hexanediol diacrylate, trimethylolpropane triacrylate, bistrihydroxydecylpropane tetraacrylate, dipentaerythritol pentaacrylate, polyether acrylate (eg ethoxylated) Trimethylolpropane triacrylate, glycerol propoxy triacrylate, ethoxylated pentaerythritol tetraacrylate, and epoxy acrylate (such as USB's Ebcryl 150), and diol diacrylate ( For example, tripropylene glycol diacrylate).

At the same time, the energy curable composition of the invention preferably comprises at least one synergist, such as a acrylate or a dimercaptoamino benzoate. In the case of printing inks, the synergist is preferably diterpene aminobenzoate, and in the case of varnish, the synergist is preferably an amino acrylate. Some inks, such as those used in flexographic printing applications, may contain two different types of synergists as described above. The amount of radiation curable monomer or oligomer, photoinitiator, synergist, and optional colorant will vary depending on the type of varnish or ink, the particular equipment used for coating, and the application. In a typical case, however, the photoinitiator plus synergist is present in an amount from 2% to 20% by weight based on the total weight of the composition.

When used as a photoinitiator in a varnish or ink, the compound of the formula (I) usually contains, in addition to the above-mentioned components, a pigment, a wax, a stabilizer and a rheology aid.

The invention is further illustrated by the following non-limiting examples. In the structural formulas listed in the examples, n represents the degree of polymerization, which can be roughly derived from the molecular weight of the compound, and the values of a plurality of η in the same structural formula may be different. Comparative example

5克对甲甲。 A. 克. 2克 (0. 7摩尔) 4-methoxybenzophenone and 87.5 grams (0.35 mole) of polytetrahydrofuran (average molecular weight of 250) was placed in 2500 liters containing 3.0 grams of A The alum-acid catalyst was subjected to azeotropic reflux for 11 hours in toluene. The solution was then washed twice with 500 ml of a 0.1 M aqueous solution of hydronium hydroxide and then twice with 500 ml of deionized water. The solution was then dried by azeotrope and all solvents were removed in vacuo using a rotary evaporator to afford 244.6 g of pale yellow liquid. Embodiment 1

Preparation of o-phenylphenoxyacetic acid ( Π ):

Take a 250ml four-necked bottle, dissolve 68.4g (0.72mol) of chloroacetic acid in 60ral water, and cool it to 0 in a low temperature bath. C, weighed 96. 0g (0. 72mol) 30% sodium hydroxide solution was added dropwise through the dropping funnel, keeping the dropping temperature < 5 . C. After the dropwise addition is completed, the obtained sodium chloroacetate solution is placed at a low temperature for use. In a 4-neck flask 1000ml 102. 0g (0. 60mol) was dissolved in ortho-phenylphenol ⁸ 0ml of water, stirring at room temperature, weighed 86. Og (0. 645mol) 30% sodium hydroxide solution was slowly added to give a slightly The brown serum was added dropwise and heated to reflux to obtain sodium o-phenylphenolate.

The prepared sodium chloroacetate solution was added dropwise to the above o-phenylphenol sodium solution through a dropping funnel, and the reaction solution was kept refluxed, and the mixture was added dropwise over 4-5 hours, and reflux was continued for 3 hours.

²⁴ ml of water was added to the reaction solution, stirred for 10 min, and then 100 ml of toluene was added, and carbon dioxide gas was introduced into the reaction flask until the pH of the reaction solution was 7.5. The stirring was stopped, and the solution was transferred to a separatory funnel to be layered. The aqueous phase was separated and the unreacted ortho-phenylphenol was extracted with 2 X 100 ml of toluene.

70 ml of concentrated hydrochloric acid was added dropwise to the aqueous phase through a dropping funnel, and the dropping temperature was maintained at 35 ° C to gradually precipitate white solid small particles.

0%。 The yield was 73.0%. The o-phenylphenol in the toluene extract can be reintroduced into the reaction.

HPLC. Purity 98. 5%; Melting point: 102. 0-104. 0 °C. Embodiment 2

Preparation of 2-(4-benzoylphenyl)-phenoxyacetic acid (1-1):

To a 250 ml four-necked flask was added 28. 5 g (0.21 mol) of 1,2-dichloroethane 60 ml; stirred, cooled with tap water; connected to a hydrogen chloride absorption device; Benzophenoxyacetic acid ( II ) 22. 8g (0. lmol ), the temperature is controlled at 20 - 30 °C.

The benzoyl chloride I ⁵ . 5g (0. llmol ) was added dropwise, and the dropping temperature ^ ^ should be kept at ²⁰ °. C - 30 ° C; after the completion of the dropwise addition, the temperature was raised to between 50 ° C and 55 ° C, and the temperature was kept at this temperature for 6 hours.

Add 50ml of concentrated hydrochloric acid to a 500ml four-necked bottle, 100ml of water, and cool to about 0 °C in a water bath. Add the above reaction droplets to the hydrochloric acid solution, keep stirring between 25 °C and 40 °C for 1 h, then cool down to - 5克的收率。 83%。 The filter cake was washed with 2 X 30ral water, and drained; the wet product was off-white powder, weighing 27. 5g, yield 83%.

HPLC analysis content 98.2%, melting point: 170-171 °C; elemental analysis C ₂₁ H _1S 0 ₄ : C 75. 70% (theoretical value 75.89%); H 4. 90% (theoretical value 4. 85%).

'HN R: 3. 71 ppm (s ₃ 1H, C00H) 4. 77 ppm (s, 2H, Ar0CH ₂ C00); 6. 88-7. 86p pm (m, 13H, Ar-). Embodiment 3

a gram of a p-toluenesulfonic acid catalyst was placed in a solution of 3-1, 8.7 g (0. 035 raol) of polytetrahydrofuran (average molecular weight of 250) and 0.3 g of p-toluenesulfonic acid catalyst. Azeotropic reflux was carried out for 2 hours in 200 ml of toluene. The reaction solution was washed twice with 50 ml of a 0.1 M aqueous sodium carbonate solution and twice with 50 ml of deionized water. Then, the solution was refluxed and the water was separated by a water separator, and toluene was removed on a rotary evaporator to give 29.3 g of pale yellow viscous. HPLC analysis results: The total content of the target product was 98.3%.

'H-NMR: 1. 59-1. 74ppm ( m, 7. 2H, CH ₂ CH ₂ ); 3. 36ppm (m, 4. 7H, CH ₂ OCH ₂ ); 4. 19-4. 23ppm (t , 2H, C00CH ₂ ); 4. 71ppm (S, 2H, Ar0CH ₂ C00); 6. 88-7. 86ppm ( m, 13H, Ar -). Embodiment 4

5克对苯酸酸酸。 Take a 1000ml four-necked bottle, 34. 9 grams (0. 105mol) of the compound 1-1, 10, 0 grams (0.05) of polyethylene glycol (average molecular weight of 200) and 0.4 grams of p-toluic acid 5小时。 Azeotropic reflux in a volume of 5. 5 hours. The reaction solution was washed twice with 100 ml of a 0.1 M aqueous solution of sodium carbonate and then twice with 100 ml of deionized water. Then dry with 5 grams of anhydrous sodium After drying overnight, the toluene was removed by filtration using a rotary evaporator to yield 39.5 g of pale yellow, high-vis. HPLC analysis results: The target content was a total of 98.5%.

"H-NMR: 3.66 - 3.76 ppm (m, 8H, CH ₂ OCH ₂ ); 4.30-4.33 ppm (t, 2H,

C0OCH ₂ ); 4.71 ppm (S ₅ 2H, Ar0CH ₂ C00); 6.88-7.86 ppm (ra, 13H, Ar-). Embodiment 5

Take a 1000 ° four-necked flask, 26.7 g (0.08 mol) of compound 1-1, 11.5 g (0.02 mol) of ethoxylated pentaerythritol (average molecular weight of 576) and 0.5 g of p-toluenesulfonic acid in 200 ml of toluene. The mixture was refluxed for 8 hours. The reaction solution was washed twice with 100 ml of a 0.1 M aqueous sodium carbonate solution and twice with 100 ml of deionized water. Then, it was dried overnight with anhydrous sodium sulfate, filtered, and then toluene was removed on a rotary evaporator to obtain a pale yellow viscous liquid, 35.5 g, yield 96.5%. HPLC analysis results: The total target content was 98.1%.

'H-NMR: 3.0 ppra (m, 2H, C - CH ₂ 0); 3.40 - 3.83 ppm (m, 8H, CH ₂ 0); 4.30-4.43 ppm (t, 2H, C00CH ₂ ); 4.71 solution (S , 2H, Ar0CH ₂ C00); 6.88-7.86 ppm (m, 13H, Ar-). Embodiment 6

Take a 1000 ml four-necked flask and place 33.2 g (0.1 mol) of compound 1-1, 15.7 g (0.025 raol) of propoxylated pentaerythritol (average molecular weight 629) and 0.8 g of p-toluene cross-acid catalyst in 200 liters. Azeotropic reflux was carried out for 6 hours in benzene. The reaction solution was washed twice with 100 ml of a 0.1 M aqueous sodium carbonate solution and twice with 100 ml of deionized water. Then use 5 grams without The solution was dried over magnesium sulfate, filtered, and then evaporated to dryness to give benzene, to give a pale yellow viscous liquid, 45.2 g, yield 96%. HPLC analysis results: The total content of the target was 98.0%. Example 7

Preparation of p-phenylphenoxyacetic acid (m):

Take a 250ml four-necked bottle, and dissolve 68.4g (0. 72mol) of chloroacetic acid in 60ml of water, and then cool it to 0°C in a low-temperature bath. Weigh 96. 0g (0. 72mol) 30% sodium hydroxide solution It was added dropwise through a dropping funnel, and the dropping temperature was kept at 5 ° C. After the dropwise addition was completed, the obtained sodium chloroacetate solution was placed at a low temperature for use.

In a 1000 ml four-necked bottle, 102.0 g (0.60 mol) of p-phenylphenol was dissolved in 80 ml of water, and stirred at room temperature, and 86.0 g (0.645 mol) of 30% sodium hydroxide solution was slowly added to obtain a slightly brownish color. The clear liquid is added dropwise, and heated to reflux to obtain sodium p-phenylphenolate.

The prepared sodium chloroacetate solution was added dropwise to the above p-phenylphenol sodium solution through a dropping funnel, and the reaction solution was kept refluxed, and the dropwise addition was completed 4 to 5 hours, and the reflux was continued for 3 hours.

240 ml of water was added to the reaction solution, stirred for 10 min, and then 100 ml of toluene was added, and carbon dioxide gas was introduced into the reaction flask until the pH of the reaction solution was -7.5. The stirring was stopped, and the solution was transferred to a separatory funnel to be layered. The aqueous phase was separated and the unreacted p-phenylphenol was extracted with 1 X 100 ml of toluene.

70 ml of concentrated hydrochloric acid was added dropwise to the aqueous phase through a dropping funnel, and the dropping temperature was < 35 ° C, and white solid small particles were gradually precipitated.

5%。 The white phenyl phenoxyacetic acid, a yield of 71. 5%. The p-phenylphenol in the toluene extract can be reintroduced into the reaction.

HPLC analysis purity 98.8%. Melting point: 186. 4-188. 3 ° C. Example eight

⁴ - (4-benzoyl-phenyl) - phenoxyacetic acid (1-2) Preparation:

5克( 0. 21mol ), 1, 2-dichloroethane was added to a 250 ml four-necked flask. 60 ml; stirred, cooled with tap water; connected to a hydrogen chloride absorption device; p-phenylphenoxyacetic acid (ΠΙ) prepared in Example 7 22. 8 g (0.1 mol), temperature controlled at 20. C-30 °C.

5克 (0. llmol), the dropping rate ^ ^ should be maintained at a temperature between 20 ° C and -30 ° C; after the addition is completed, the temperature is raised to between 50 ° C and 55 ° C. This temperature was kept at this temperature for 6 hours.

Add 50ml of concentrated hydrochloric acid to 100ml four-necked bottle, water 100ml, water drops to about TC, add the above reaction drops to hydrochloric acid solution, keep stirring between 25 °C and 40 °C for lh, then cool down to - 5%。 The yield is 78. 5%. The yield is 78. 5%. The yield is 78.5%.

HPLC analysis content 98. 5%; melting point: 205. 0 - 206. 2 °C.

Elemental analysis C ₂₁ H ₁₆ 0 ₄ : C 75. 70% (theoretical value 75. 89%); H 4, 89% (theoretical value 4.91%).

'H-NMR: 4.75 ppm (s, 2H, Ar0CH ₂ C00); 7. 03-7. 82 ppm (m, 13H, Ar -). Example nine

5克对苯苯苯硫酸硫酸催化剂。 Take a 1000ml four-necked bottle, 23. 3g (0. 07mol) of the compound I-2, 8. 7g (0. 035mol) polytetrahydrofuran (average molecular weight of 250) and 0.3 grams of p-toluenesulfonic acid catalyst Azeotropic reflux was carried out in 200 ml of toluene for 5 hours. The reaction solution was washed twice with 50 ml of a 0.1 M aqueous sodium carbonate solution and twice with 50 liters of deionized water. Then, the solution was refluxed and the water was separated by a water separator, and toluene was removed on a rotary evaporator to give 29.0 g of pale yellow viscous, yield: 95.3%. HPLC analysis results: total target content 98. 4%.

'H-NMR: 1. 59-1. 74ppm (m, 7. 2H, CH ₂ CH ₂ ); 3. 36ppm (m, 4. 7H, CH ₂ 0CH ₂ ); 4. 19-4. 23ppm (t , 2H, C00CH ₂ ); 4. 69ppm (S, 2H, Ar0CH ₂ C00); 7. 03-7. 82ppm ( m, 13H, Ar -). Example ten

A 1000 ml four-necked flask was taken, and 26.7 g (0. OSmol) of compound 1-2, 11.5 g (0.02 mol) of ethoxylated pentaerythritol (average molecular weight of 576) and 0.5 g of p-toluenesulfonic acid were placed in 200 ml of toluene. Azeotropic reflux was carried out for 8 hours. The reaction solution was washed twice with 100 ml of aq. sodium hydrogen carbonate aqueous solution and twice with 100 ml of deionized water. Then, it was dried overnight with anhydrous sodium citrate, filtered, and then, toluene was removed on a rotary evaporator to obtain a pale yellow viscous liquid, 35.3 g, yield 96.0%. HPLC analysis results: The total target content was 98.0%.

'HN R: 3. Oppm (m, 2H, C - CH ₂ 0); 3.40 - 3.83 ppm (m, 8H, CH ₂ 0); 4.30-4.43 ppm (t, 2H, C00CH ₂ ); 4.69 ppm (S , 2H, Ar0CH ₂ C00); 7.03-7.82 ppm (m, 13H, Ar -).

The sources of the reagents used in the above experiments are shown in Table 1 below. Material Name Supplier

O-phenylphenoxyacetic acid Jiangsu Yingli Branch Exhibition Co., Ltd.

P-phenylphenoxyacetic acid Jiangsu Yingli Branch Exhibition Co., Ltd.

Benzoyl chloride Beijing Chemical Reagent Company

Aluminum trichloride Tianjin Jingjin Pesticide Factory

1,2-dichloroethane Zibo Fuzhong Chemical Plant

36% hydrochloric acid Beijing Beihua Fine Chemical Co., Ltd.

1, 4-dioxane Jiangsu Taixing Jiangteng Pharmaceutical Chemical Factory

PTHF250 BASF

P-toluenesulfonic acid Shanghai Wulian Chemical Plant

Toluene Zhoucun Jinyuan Chemical Plant

30% sodium hydroxide solution Tianjin Haotian Chemical Co., Ltd.

Polyethylene glycol 200 Beijing Huayou Chemical Factory

Ethoxylated pentaerythritol Tianjin Tianjiao Chemical Co., Ltd.

Propoxylated pentaerythritol Tianjin Tianjiao Chemical Co., Ltd.

Embodiment 11 Curing performance comparison

The products prepared in the above Examples 3 to 6, 9, and 10, and the comparative examples were used as photoinitiators to prepare corresponding ultraviolet curable varnish preparations, and benzophenone and phenylbenzophenone were also used. The photoinitiator is formulated into a corresponding UV curable varnish formulation. The formulation of the formulation is shown in Table 2.

The resulting varnish formulation was applied to a tinplate using a 10 micron bar coater and cured at a speed of 100 meters per minute using a 60 watt/cm medium pressure mercury arc lamp. Record the number of passes under the lamp required to obtain a good surface and complete cure. The results are shown in the table below.

These results indicate that the compound of the present invention is at least equivalent to or close to the curing speed of benzophenone in terms of curing speed. All examples showed lower odor than benzophenone after curing. All examples have similar yellowness after curing.

Claims

Claim

1. A compound represented by the formula (I)

among them:

A is 0, G is H, X = 1;

Or,

X is an integer, JL2<x<N;

A stands independently of each other "tOCHI^CHR^^^ - O(CH ₂ ) _b CO3⁄4r or

Group, where:

One of R ¹ and R ² represents a hydrogen atom, and the other represents a hydrogen atom, a methyl group or an ethyl group; a is 1 or 2;

b is 4 or 5;

y is an integer from 1 to 10.

^2. A compound as claimed in claim 1, wherein -0- attached to the phenyl ring in formula (I) is ortho or para to the benzophenone group.

The compound according to claim 1 or 2, wherein A represents a group of the formula ~f OCCHI^CHR^ y .

4. A compound according to claim 3, wherein A represents a "" + 0C¾CH ₂ ¾r,

-fOCH ₂ CH ₂ CH ₂ CH ₂ 3⁄4r or ~ OCH(CH ₃ )C3⁄43⁄4r.

Or the compound of formula 12 wherein A represents ~ fO (CH ₂₎ _b CO¾T group claim.

The compound according to claim 1 or 2, wherein A represents

~^0(σ3⁄4)^0·^ O HR HR ¹ )^ The group.

The compound according to claim 1 or 2, wherein the residue G-(A-) has a molecular weight of not more than 1200.

The compound according to claim 1 or 2, wherein the residue G- (A- molecular weight is not more than 800.

The compound according to claim 1 or 2, wherein G is a residue of ethylene glycol, propylene glycol, butylene glycol, glycerol, trimethylolpropane, bistrihydroxydecylpropane, pentaerythritol or pentaerythritol.

A method for producing a compound represented by the formula (I), which comprises:

Ethyl 2-(4-benzoylphenyl)-phenoxyacetic acid or 4-(4-benzoylphenyl)-phenoxyacetic acid is esterified with a compound of the formula (HA) _X - G.

11. Use of a compound according to any one of claims 1-9 as a photoinitiator.

A composition characterized by comprising two or more compounds according to any one of claims 1 to 9 in any ratio.

A photoinitiator characterized by comprising at least one compound according to any one of claims 1-9.

14. An energy curable liquid composition characterized by comprising the following components:

a polymerizable component comprising at least one ethylenically unsaturated monomer or oligomer; the photoinitiator of claim 13.

15. The energy curable liquid composition of claim 14 which is a varnish or printing ink.

16. A method of preparing a cured polymeric composition comprising exposing the energy curable liquid composition of claim 14 or 15 to ultraviolet radiation.