Organic phosphorus initiator and preparation method thereof, and photocurable composition

Abstract

The present invention provides an organophosphorus initiator and a preparation method thereof, and a photocurable composition. The organophosphorus initiator has a structure shown in the general formula I. wherein R1 represents a C1-C4 straight chain or branched chain alkyl; R a , R b independently represent hydrogen, C1-C 20 A straight chain or branched alkyl group; p and q independently represent an integer of 1 to 5; X represents a chlorine atom or a bromine atom. When the above-mentioned organophosphorus initiator is used in a photocurable composition, it has better solubility than a conventional organophosphorus initiator and has good reactivity. It can be used not only in a free radical initiation system but also in a hybrid system and can be cured thoroughly. At the same time, the initiator has a large molecular weight and contains a polymerizable group in its structure, so it is not easy to volatilize or migrate, and the atomic utilization rate is high. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the field of organic chemistry, and in particular to an organophosphorus initiator and a preparation method thereof, and a photocurable composition. Background Art

[0002] With the development of photosensitive resin compositions, people have put forward higher requirements for photoinitiators. Acylphosphine photoinitiators are widely used due to their extremely high polymerization initiation activity, high sensitivity and wide photosensitivity range. The commonly used photoinitiators are:

[0003]

[0004] However, the photoinitiator TPO may be banned or restricted in many applications due to its reproductive toxicity. Many of its homologous initiators may also face this problem. The curing rate, color and solubility of similar products are also factors that need to be considered.

[0005] In recent years, CN109897063A, CN107916026A, and CN106554430A have reported organic phosphorus initiators with different structures, but their reactions are relatively complex, and the three wastes in the reaction process have always been a goal to be solved. In addition, these initiators have no initiation effect in a mixed system, and it is speculated that the ultraviolet absorption and other structures in the system produce competitive absorption. Therefore, an organic phosphorescent initiator with simple reaction, less three wastes, good product activity, and excellent solubility is the goal pursued in the industry. Summary of the invention

[0006] The main purpose of the present invention is to provide an organophosphorus initiator and a preparation method thereof, and a photocurable composition, so as to solve the problems of low atom utilization, insufficient product activity and insufficient solubility in the application process of the organophosphorus initiator in the prior art.

[0007] In order to achieve the above object, according to one aspect of the present invention, an organophosphorus initiator is provided, which has a structure shown in general formula I:

[0008]

[0009] Wherein, R1 represents a C1-C4 straight chain or branched chain alkyl group; R a , R b independently represent hydrogen, C1-C 20 p and q independently represent an integer of 1 to 5; X represents a chlorine atom or a bromine atom.

[0010] Furthermore, R1 is methyl or ethyl, preferably ethyl.

[0011] Furthermore, Ra and R b Each independently represents hydrogen or a C1-C5 straight-chain or branched alkyl group.

[0012] Furthermore, R a and R b Independently of each other, they represent hydrogen or methyl.

[0013] Furthermore, the organophosphorus initiator is one or more of the following compounds:

[0014]

[0015]

[0016] According to another aspect of the present invention, there is also provided a method for preparing the above-mentioned organophosphorus initiator, which comprises the following steps:

[0017] Step S1, hydrolyzing the raw material a under alkaline conditions to obtain an intermediate b;

[0018]

[0019] Step S2, reacting the intermediate b and the raw material c under the action of an acid binding agent to obtain an intermediate d;

[0020]

[0021] Step S3, reacting the intermediate d with the raw material e to obtain an organophosphorus initiator;

[0022]

[0023] Among them, R1, R a , R b , p, q, and X have the same definitions as above.

[0024] Furthermore, in step S1, the alkaline condition is provided by a base, and the base is selected from one or more of sodium hydroxide, potassium carbonate, potassium hydroxide, and sodium carbonate; preferably, the reaction temperature of the hydrolysis reaction is ≤10°C, and the reaction time is 2 to 6 hours; preferably, step S1 comprises: mixing the raw material a and the aqueous solution of the base to form a first pre-reaction system, and then performing a hydrolysis reaction to obtain an intermediate b; the concentration of the aqueous solution of the base is 10 to 20wt%, and the weight ratio of the raw material a to the aqueous solution of the base is 1:3 to 8.

[0025] Furthermore, the acid-binding agent is selected from one or more of sodium carbonate, sodium hydroxide, potassium carbonate, sodium methoxide, pyridine, and triethylamine; preferably, the reaction temperature in step S2 is ≤10°C, and the reaction time is 1 to 4 hours; preferably, the molar ratio of raw material b to raw material c is 1:(1 to 1.4), and the amount of the acid-binding agent is 2 to 4 times the weight of raw material b; preferably, the reaction in step S2 is carried out in a first organic solvent, and the first organic solvent is selected from one or more of dichloromethane, dichloroethane, toluene, and benzene.

[0026] Furthermore, the reaction temperature in step S3 is 60-150° C., and the reaction time is 2-4 h; preferably, the molar ratio of the intermediate d to the raw material e is 1:(1-2); preferably, the reaction in step S3 is carried out in a second organic solvent, and the second organic solvent is selected from one or more of dichloromethane, benzene, toluene, xylene, and N,N-dimethylformamide.

[0027] According to another aspect of the present invention, there is provided a photocurable composition, comprising a photoinitiator, which is one or more of the above-mentioned organophosphorus initiators; preferably, the photocurable composition is a free radical system or a hybrid system of a free radical system and a cationic system.

[0028] The present invention provides an organophosphorus initiator having a structure of general formula I. When applied to a photocurable composition, the initiator has better solubility than a conventional organophosphorus initiator and has good reactivity. The initiator can be applied not only to a free radical initiation system but also to a mixed system and has a good initiation effect and can be cured thoroughly. At the same time, the initiator has a large molecular weight and contains a polymerizable group in the structure, so it is not easy to volatilize or migrate, and the atomic utilization rate is high. In addition, the initiator has a high raw material utilization rate during the preparation process, and even has no by-products. No diluent is required during the preparation process, and the preparation process is economical and environmentally friendly. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0030] As described in the background technology section, the prior art organic phosphorus initiator synthesis process produces a lot of three wastes, and there are problems such as low atomic utilization, insufficient product activity, and insufficient solubility during application.

[0031] In order to solve the above problems, the present invention provides an organophosphorus initiator having a structure shown in general formula I:

[0032]

[0033] Wherein, R1 represents a C1-C4 straight chain or branched chain alkyl group; Ra , R b independently represent hydrogen, C1-C 20 p and q independently represent an integer of 1 to 5; X represents a chlorine atom or a bromine atom.

[0034] The present invention provides an organophosphorus initiator having a structure of general formula I. When applied to a photocurable composition, the initiator has better solubility than a conventional organophosphorus initiator and has good reactivity. The initiator can be applied not only to a free radical initiation system but also to a mixed system and has a good initiation effect and can be cured thoroughly. At the same time, the initiator has a large molecular weight and contains a polymerizable group in the structure, so it is not easy to volatilize or migrate, and the atomic utilization rate is high. In addition, the initiator has a high raw material utilization rate during the preparation process, and even has no by-products. No diluent is required during the preparation process, and the preparation process is economical and environmentally friendly.

[0035] It should be noted that when R a , R b When R is a hydrogen atom, there is no substituent on the corresponding benzene ring of the general formula I, and p and q are 5. a , R b C1-C 20 A straight chain or branched alkyl group, p and q represent the number of substituents. p is 5 and q is 1.

[0036] In order to further balance the performance of the initiator in various aspects so as to give it better activity, solubility and good atom utilization, in a preferred embodiment, R1 is methyl or ethyl, preferably ethyl.

[0037] While improving the comprehensive performance, taking into account the raw materials and cost issues, in a preferred embodiment, R a and R b independently represent hydrogen, C1-C5 straight or branched alkyl; preferably R a and R b Independently of each other, they represent hydrogen or methyl.

[0038] Exemplarily, the above-mentioned organophosphorus initiator is one or more of the following compounds:

[0039]

[0040]

[0041] According to another aspect of the present invention, there is also provided a method for preparing the above-mentioned organophosphorus initiator, which comprises the following steps:

[0042] Step S1, hydrolyzing the raw material a under alkaline conditions to obtain an intermediate b;

[0043]

[0044] Step S2, reacting the intermediate b and the raw material c under the action of an acid binding agent to obtain an intermediate d;

[0045]

[0046] Step S3, reacting the intermediate d with the raw material e to obtain an organophosphorus initiator;

[0047]

[0048] Among them, R1, R a , R b , p, q, and X have the same definitions as described above.

[0049] The preparation method has simple procedures, high raw material utilization rate, and no by-products. No diluent is needed during the preparation, and the preparation process is economical and environmentally friendly. The prepared organophosphorus initiator has good reactivity and solubility in the photocurable composition, and is completely cured and not easy to migrate, and has good comprehensive performance. The initiator can not only be applied to free radical systems, but also has a photosensitizing effect on mixed systems.

[0050] The raw material a, raw material c and raw material e used in the above preparation method are all known compounds in the prior art, or can be prepared by a preparation method known in the prior art.

[0051] In order to further improve the efficiency of the hydrolysis reaction, in a preferred embodiment, in step S1, the alkaline condition is provided by a base, and the base is selected from one or more of sodium hydroxide, potassium carbonate, potassium hydroxide, and sodium carbonate; more preferably, the reaction temperature of the hydrolysis reaction is ≤10°C, and the reaction time is 2 to 6 hours.

[0052] Preferably, step S1 comprises: mixing raw material a and an aqueous solution of alkali to form a first pre-reaction system, and then performing a hydrolysis reaction to obtain an intermediate b; the concentration of the aqueous solution of alkali is 10-20wt%, and the weight ratio of raw material a to the aqueous solution of alkali is 1:3-8. By controlling the amount of each raw material within the above range, the pH environment of the hydrolysis reaction system is more suitable, and the excessive waste of auxiliary raw materials can be avoided on the basis of improving the reaction efficiency.

[0053] In the presence of an acid binding agent, the reaction of intermediate b and raw material c can be promoted to proceed in the forward direction. In order to improve the purification effect of intermediate d on the basis of further improving the reaction efficiency, while considering the cost of raw materials and further improving the environmental protection of production, in a preferred embodiment, the acid binding agent is selected from one or more of sodium carbonate, sodium hydroxide, potassium carbonate, sodium methoxide, pyridine, and triethylamine. At the same time, in order to further improve the reaction stability and safety, preferably, the reaction temperature in step S2 is ≤10°C, and the reaction time is 1 to 4h. In the actual reaction process, the reaction temperature may be slightly different depending on the type of raw materials, which can be adjusted by those skilled in the art through actual reactions.

[0054] Preferably, the molar ratio of raw material b to raw material c is 1:(1-1.4), and the amount of the acid binding agent is 2-4 times the weight of raw material b. Controlling the amount of each reaction raw material within the above range makes the reaction more efficient and avoids excessive waste of raw materials.

[0055] In order to further improve the reaction stability, in a preferred embodiment, preferably, the reaction in step S2 is carried out in a first organic solvent. The present invention does not particularly limit the type of solvent used, as long as it can dissolve the reaction raw materials and has no adverse effect on the reaction. For example, the first organic solvent can be selected from one or more of dichloromethane, dichloroethane, benzene, and toluene. The specific reaction concentration can be adjusted.

[0056] In a preferred embodiment, the reaction temperature in step S3 is 60-150° C., and the reaction time is 2-4 hours. Under this temperature condition, the reaction of intermediate e and raw material c is more efficient. Preferably, the molar ratio of intermediate d to raw material e is 1:(1-2). Controlling the weight ratio of the two within the above range can improve the reaction efficiency while avoiding excessive waste of raw materials.

[0057] Preferably, the reaction in step S3 is carried out in a second organic solvent. The present invention does not particularly limit the type of solvent used, as long as it can dissolve the reaction raw materials and has no adverse effect on the reaction. For example, the second organic solvent can be selected from one or more of dichloromethane, benzene, toluene, xylene, and N,N-dimethylformamide.

[0058] In each of the above steps, the utilization rate of the reaction raw materials is high, there is basically no by-product, and after the reaction, the purification and solvent recovery can be carried out by the commonly used methods in the field of organic synthesis, and the recovered solvent can also be recycled, so basically no three wastes are generated, which is more environmentally friendly. Preferably, in the above step S1, after the hydrolysis reaction, the reaction liquid is extracted with ethyl acetate to obtain an organic phase; the organic phase is concentrated under reduced pressure to obtain an intermediate b; in the above step S2, after the reaction is completed, filtering and concentrating are carried out in sequence to obtain an intermediate d; in the above step S3, after the reaction is completed, filtering and recrystallization are carried out in sequence to obtain an organophosphorus initiator.

[0059] According to another aspect of the present invention, there is provided a photocurable composition, comprising a photoinitiator, which is one or more of the above-mentioned organophosphorus initiators; preferably, the photocurable composition is a free radical system or a hybrid system of a free radical system and a cationic system.

[0060] Exemplarily, the above-mentioned photocurable composition is a coating used for coating on substrates such as plastic, metal, glass, ceramic, wood, wall, optical fiber, etc.; protective film materials such as hard coating agents, anti-fouling films, anti-reflective films, impact buffer films, etc.; photocurable adhesives, adhesives, photodegradable coatings, coatings, molded objects; optical recording media such as holographic imaging materials; optical molding resins, for example, inks (resins) for 3D printing, photoresists for electronic circuit and semiconductor manufacturing, photoresists for electronic materials such as color filters, black matrices, dry films in displays, etc.; interlayer insulating films, light extraction films, brightening films, sealing materials; printing inks such as screen printing, offset printing, gravure printing, etc., photocurable inks for inkjet printing; optical components such as lenses, lens arrays, optical waveguides, light guide plates, light diffusers, diffraction elements, etc.; optical spacers, rib walls, materials for nanoimprinting, etc.

[0061] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0062] Preparation Example

[0063]

[0064] (1) Preparation of intermediate b

[0065] Add 50 g of 15% sodium hydroxide aqueous solution into a 100 ml four-necked bottle, stir the system and cool it down by 5-10°C, slowly add 15.8 g of raw material a, and the addition is completed in about 30 minutes. After the addition is completed, continue to keep warm and stir at 5-10°C for 2 hours. GC is used to track the reaction progress. When the content of raw material a is <1%, stop stirring, adjust the pH of the system to 7-8 with concentrated hydrochloric acid, extract the reaction solution with ethyl acetate (50 mL*3), combine the organic layers, wash the organic layer once with saturated sodium chloride, separate the liquids, and concentrate the organic phase under reduced pressure to obtain b, and a total of 16.2 g of product b is obtained.

[0066] Product b was further confirmed by NMR: 1 H NMR(500MHz,Chloroform-d)δ5.80(s,2H),5.42-5.38(t,1H),5.22(brs,1H),4.9 4(brs,1H),4.25(s,4H),3.98-3.73(m,2H),1.71-1.65(m,2H),0.88-0.82(t,3H).

[0067] (2) Preparation of intermediate 1d

[0068]

[0069] To a 500ml four-necked flask, 250mL of dichloromethane, 30.0g of triethylamine and 17.6g of compound b were added. The temperature was cooled to below 0°C with stirring, and 18.7g of raw material 1c was slowly added dropwise. The addition took about 30 minutes. After the addition was completed, the temperature was slowly raised to room temperature. Stirring was continued for 2h. The reaction was monitored by TLC. After the reaction was complete, the reaction solution was washed with water (50mL*3), separated and the organic phase was concentrated to obtain a crude product 1d. 25g of methanol was added to the crude product 1d and slurried at room temperature to obtain 26.4g of solid 1d.

[0070] Product 1d was further confirmed by NMR: 1 H NMR (500MHz, Chloroform-d) δ7.42-7.15(m,5H),5.80(s,2H),5.42-5.38(m,1H),4.24(s,4H),3.98-3.73(m,2H),1.71-1.66(q,2H),0.83-0.87(t,3H).

[0071] (3) Preparation of product 1f:

[0072]

[0073] To a 100 ml four-necked flask, 14.1 g of intermediate 1d and 50 mL of toluene were added. The temperature was raised to 100 °C, and 7.5 g of raw material 1e was added dropwise. The addition was completed in about 30 min. After the addition was completed, the mixture was kept at 100 °C and stirred for 2 h. The reaction was tracked by HPLC. When the raw material 1d was <1%, stirring was stopped, and the reaction solution began to cool to 0 °C. Compound 1f was obtained by filtration, and recrystallization with methanol gave a light yellow solid product 1f: 17.6 g.

[0074] Product 1f was further confirmed by NMR: 1 H NMR(500MHz,Chloroform-d)δ7.85-7.61(m,5H),7.31-7.24(m,5H),5.80(s,2H),5.2 9-5.27(m,1H),4.57-4.51(m,2H),4.25(s,4H),1.73-1.68(q,2H),0.87-0.82(t,3H).

[0075] It can be seen from the synthesis of the above products that the synthesis is relatively simple, no by-products are produced, and the atomic utilization rate is high.

[0076] (4) Preparation of Examples 2-9

[0077] Referring to the method of the example, the product 2-9 having the following structure was synthesized (see Table 1 for details).

[0078] Table 1

[0079]

[0080]

[0081] Performance Evaluation

[0082] The application performance of the initiator of the present invention was evaluated by preparing an exemplary photocurable composition (i.e., a photosensitive resin composition, parts by mass). The application composition components in the free radical system photocurable composition are shown in Table 2, and the application composition components in the hybrid system photocurable composition are shown in Table 3. The lighting conditions of the composition in the table are divided into mercury lamp irradiation, 385nm ultraviolet light irradiation, and 405nm ultraviolet light irradiation, as shown in the table for details.

[0083] Table 2 Free radical system

[0084]

[0085] Table 3 Hybrid system

[0086]

[0087]

[0088] 6110: 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, Tytel

[0089] E201: Bisphenol A epoxy acrylate, Jiangsu Kailin Ruiyang Chemical Co., Ltd.

[0090] TMPO: 3-Hydroxymethyl-3-ethyloxetane, Changzhou Qiangli Electronic New Materials Co., Ltd.

[0091] TMPTA: Trimethylolpropane triacrylate, Jiangsu Kailin Ruiyang Chemical Co., Ltd.

[0092] BYK307: Leveling agent, BYK, Germany

[0093] PAG30101: 4,4-Dimethylphenyliodonium hexafluorophosphate, Changzhou Qiangli Electronic New Materials Co., Ltd.

[0094] Titanium dioxide: Shandong Yufeng Chemical Co., Ltd.

[0095] PSS306: 9,10-diethoxy-2-ethylanthracene, Changzhou Qiangli Electronic New Materials Co., Ltd.

[0096] 184: Hydroxycyclohexyl phenyl ketone, Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0097] TPO: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, Changsha Xinyu Polymer Technology Co., Ltd.

[0098] TPO-L: 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, Changsha Xinyu Polymer Technology Co., Ltd.

[0099] 2. Performance evaluation method

[0100] (1) Sensitivity evaluation

[0101] The photocurable composition was stirred and mixed under a yellow light lamp, and the material was rolled onto a PET template to form a film with a thickness of about 50 μm. According to the corresponding method in the table, a mercury lamp (100%, 1 m / min, 1140 mJ), an LED 385 nm (100%, 3 m / min, 2568 mJ / cm 2 ), LED405nm (100%, 3m / min, 2568mJ / cm 2 ) were exposed respectively, and the curing of the composition was observed and evaluated according to the following standards:

[0102] 1. Oil, not solid

[0103] 2. Surface oil, bottom layer solidified

[0104] 3. The surface is sticky and fingerprints are heavy after touching it.

[0105] 4. Basically dry, slightly astringent to the touch, light fingerprints

[0106] 5. Completely cured, smooth surface, no fingerprints after touch

[0107] The test results are shown in Table 4:

[0108] Table 4

[0109]

[0110]

[0111] Experiments show that the initiator of the present invention can be applied not only to free radical systems but also to mixed systems, and has a long-wavelength initiator effect.

[0112] In summary, the initiator of the present invention shows very excellent application performance in the field of photocuring and has broad application prospects. In addition, the initiator of the present invention is not limited to the application field of photocuring, and all systems such as coatings, inks, adhesives and photoresists, as long as the initiator of the present invention is used, are within the protection scope of the present invention.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An organophosphorus initiator, characterized in that: It has the structure shown in general formula I: Wherein, R1 represents a C1-C4 straight chain or branched chain alkyl group; R a and R b Independently represent hydrogen, C1-C5 straight or branched alkyl; p and q independently represent an integer of 1 to 5; X represents a chlorine atom or a bromine atom.

2. The organophosphorus initiator according to claim 1, characterized in that: R1 is methyl or ethyl.

3. The organophosphorus initiator according to claim 1, characterized in that: R1 is ethyl.

4. The organophosphorus initiator according to any one of claims 1 to 3, characterized in that R a and R b independently represent hydrogen or methyl.

5. The organophosphorus initiator according to claim 1, characterized in that: The organophosphorus initiator is one or more of the following compounds:

6. A method for preparing the organophosphorus initiator according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step S1, hydrolyzing the raw material a under alkaline conditions to obtain an intermediate b; Step S2, reacting the intermediate b and the raw material c under the action of an acid binding agent to obtain an intermediate d; Step S3, reacting the intermediate d with the raw material e to obtain the organophosphorus initiator; Among them, R1, R a , R b , p, q, and X have the same definitions as in any one of claims 1 to 5.

7. The preparation method according to claim 6, characterized in that: In step S1, the alkaline condition is provided by a base, and the base is selected from one or more of sodium hydroxide, potassium carbonate, potassium hydroxide, and sodium carbonate.

8. The preparation method according to claim 7, characterized in that: The reaction temperature of the hydrolysis reaction is ≤10°C, and the reaction time is 2 to 6 hours.

9. The preparation method according to claim 7, characterized in that: The step S1 comprises: mixing the raw material a and the aqueous solution of alkali to form a first pre-reaction system, and then performing the hydrolysis reaction to obtain the intermediate b; the concentration of the aqueous solution of alkali is 10-20wt%, and the weight ratio of the raw material a to the aqueous solution of alkali is 1:3-8.

10. The preparation method according to claim 6, characterized in that: The acid binding agent is selected from one or more of sodium carbonate, sodium hydroxide, potassium carbonate, sodium methoxide, pyridine and triethylamine.

11. The preparation method according to claim 10, characterized in that: The reaction temperature in step S2 is ≤10° C. and the reaction time is 1 to 4 hours.

12. The preparation method according to claim 10, characterized in that: The molar ratio of the raw material b to the raw material c is 1: (1-1.4), the amount of the acid binding agent used is 1-3 times the weight of the raw material b.

13. The preparation method according to claim 10, characterized in that: The reaction in step S2 is carried out in a first organic solvent, and the first organic solvent is selected from one or more of dichloromethane, dichloroethane, toluene, and benzene.

14. The preparation method according to claim 6, characterized in that: The reaction temperature in step S3 is 60-150° C., and the reaction time is 2-4 hours.

15. The preparation method according to claim 14, characterized in that: The molar ratio of the intermediate d to the raw material e is 1:(1-2).

16. The preparation method according to claim 14, characterized in that: The reaction in step S3 is carried out in a second organic solvent, and the second organic solvent is selected from one or more of dichloromethane, benzene, toluene, xylene, and N,N-dimethylformamide.

17. A photocurable composition comprising a photoinitiator, characterized in that: The photoinitiator is one or more of the organophosphorus initiators described in any one of claims 1 to 5.

18. The photocurable composition according to claim 17, characterized in that: The photocurable composition is a free radical system or a hybrid system of a free radical system and a cationic system.

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