CN102167760A - Cationic polymerization or cation-free radical mixed polymerization type photopolymerization curing system - Google Patents

Abstract

The invention discloses a photopolymerization curing system of cation polymerization or cation-radical mixed polymerization, which belongs to the technical field of preparation of optical functional materials for imaging information recording. The curing system is composed of 86-89 parts by weight of photosensitive monomer whose terminal group is vinyl ether and allyl ether, 1-4 parts by weight of photopolymerization initiator and 7-13 parts by weight of solvent. The composition of the curing system can be used in nanoimprint technology to produce corresponding images, photocurable coatings, or used in negative resists to obtain negative images. The free radical photopolymerization reaction and the cationic photopolymerization reaction occur simultaneously in the curing system, and the system takes advantage of the advantages of the two kinds of polymerization reactions at the same time, and has fast curing rate, low viscosity and low shrinkage.

Description

A photopolymerization curing system for cationic polymerization or cationic-radical mixed polymerization

technical field

The invention belongs to the technical field of preparation of optical functional materials for imaging information recording, and in particular relates to a photopolymerization curing system of cation polymerization or cation-radical mixed polymerization.

Background technique

Photopolymerization (also known as photocuring) refers to the process in which liquid oligomers (including monomers) undergo cross-linking polymerization to form solid products under the action of light (ultraviolet or visible light). UV curing has the advantages of no organic solvent, less environmental pollution, fast curing speed, energy saving, good performance of cured products, suitable for high-speed automatic production lines and coating on heat-sensitive substrates, etc.

Photopolymerization (light curing) technology is widely used in coatings, inks, adhesives, packaging materials for the electronics industry, photoresists, and printing materials, dental restorations, and biomaterials (Yang Yongyuan, Wu Yumin, Hu Hui, Tan Haoya . Current status and some progress of radiation-curable materials [J1. Photosensitive Science and Photochemistry, 2002, 20(3): 230-238.). Because of its fast curing speed, low energy consumption, no environmental pollution, and excellent coating performance, it has developed rapidly all over the world since the first successful development of UV-curable coatings by German Bayer in 1967 (Deeker C. Kinetic study and new applications of UV radiation curing[J].Maeromol.; Rapid Conunun.[J]2002,23(18):1067-1093).

Photopolymerization can be divided into free radical polymerization and cationic polymerization according to different initiation mechanisms. In the case of these technologies being continuously applied, various polymerization reactions have shown their advantages and disadvantages. Free radical photopolymerization has some serious disadvantages: First, free radical photopolymerization is severely inhibited by oxygen, which is easy to cause poor surface curing, and often needs to be cured under an inert atmosphere, which is inconvenient to operate; secondly, free radical photopolymerization is usually accompanied by this Larger volume shrinkage. Compared with the free radical photocuring system, the cationic photopolymerization system has the following advantages: it is not inhibited by oxygen, the volume shrinkage of the polymerization chamber is small, and the formed polymer has stronger adhesion; the active center has a long life, and the curing reaction is not easy to terminate; more importantly, Its initiation mechanism does not involve free radicals and excited triplet states, so it is not inhibited by oxygen, and rapid and complete polymerization can be obtained in air atmosphere. However, the cationic polymerization system also has its own shortcomings, such as being greatly affected by moisture, slow polymerization speed, and variable performance adjustment. The use of photocation-free radical hybrid photocuring system can learn from each other's strengths and make full use of the characteristics of free radical and cationic photocuring systems, thereby broadening the scope of application of photocuring systems, which is called hybrid photopolymerization.

The so-called hybrid photocuring refers to the process in which two or more different types of polymerization reactions (such as free radical polymerization and polycondensation, free radical polymerization and cationic polymerization) proceed simultaneously in the same system. There is a special case where different types of polymerization reactions in the system are realized through two stages. Such a system is called a double polymerization system, which is a hybrid polymerization system in a broad sense. Hybrid polymerization and double polymerization are different from copolymerization modification, which produce polymer alloys instead of copolymers; they are also different from blending, they form polymer alloys in situ, and it is possible to obtain interpenetrating network structures (positive N), thus So that the polymer product has better comprehensive performance. Hybrid polymerization combines the advantages of each polymerization reaction, showing a good synergistic effect, and is a new method for the modification of polymer materials.

Contents of the invention

The present invention provides a photopolymerization curing system composition of cationic polymerization or cationic-radical mixed polymerization, the core of which is a photosensitive monomer whose terminal group is vinyl ether and allyl ether, and its specific composition is:

(1) The end group of 86-89 parts by weight is a photosensitive monomer of vinyl ether and allyl ether;

(2) The photopolymerization initiator of 1-4 weight part;

(3) 7-13 parts by weight of solvent.

The photosensitive monomer whose end group is vinyl ether and allyl ether is shown in the following formula:

In the formula, R ₁ is a vinyl ether alkoxy group, and the structural formula is Wherein R _is H, an alkyl or phenyl group with 1-4 carbon atoms, and a is an integer of 1-10;

其中R₈为H、碳原子数为R ₂ is an allyl ether alkoxy group, and the structural formula is

Wherein R ₈ is H, and the number of carbon atoms is

1-4 alkyl or phenyl, b is an integer of 1-10;

R ₃ , R ₄ , R ₅ , R ₆ are H, CH ₃ , phenyl or p-methylphenyl;

n is an integer of 0-10; m is an integer of 1-10.

The specific structural formulas of the photosensitive monomers whose end groups are vinyl ether and allyl ether are as follows: monomers A-1 to A-24:

Monomers B-1 to B-24:

Monomers C-1 to C-24:

Monomers D-1 to D-24:

Monomers E-1 to E-24:

The photopolymerization initiator is a cationic photopolymerization initiator and a free radical photopolymerization initiator, specifically a mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG201, a mixed triaryl fluorosulfonium antimonate cation Photoinitiator PAG202, triaryl fluoroantimonate sulfonium salt cationic photoinitiator 445, free radical initiator ITX, free radical initiator 907, free radical initiator 784, free radical initiator TPO, free radical initiator BAPO one or several.

Described solvent is ethyl lactate, butyl acetate, pentyl acetate, ethyl pyruvate, ethylene glycol ethyl ether acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether acetate, acetone, methyl isobutyl One or more of ketone, 2-heptanone and cyclohexanone, γ-butyrolactone, cyclohexane, tetrahydrofuran. These solvents sufficiently dissolve the components, have a moderate drying rate and provide a uniform, smooth coating after the solvent has evaporated.

The composition of the photopolymerization curing system of cationic polymerization or cationic-free radical mixed polymerization prepared by the present invention has a core containing a silicon-containing photosensitive monomer whose terminal group is vinyl ether and allyl ether, and the monomer is activated by free radicals. Under the co-existence of an agent and a cationic initiator, cationic polymerization and free radical polymerization are initiated by ultraviolet light. Advantages, but eliminates the disadvantages of the two reactions, making it less sensitive to oxygen and moisture. The composition of the curing system has a high degree of polymerization and a fast polymerization rate. At the same time, the silicon-containing monomer can be used as a nanoimprint resist to improve wear resistance and dry etching resistance, and the surface tension of the silicon chain is reduced, so that The viscosity is lower, and the uniformity of film formation is improved. The maximum absorption wavelength of this monomer is 200nm, which is stable to visible light, making storage and transportation more convenient. The composition of the curing system can be used in nanoimprint technology to produce corresponding images, photocurable coatings, or used in negative resists to obtain negative images.

Detailed ways

Example:

Dissolve the cationic photopolymerization initiator and the photosensitive monomer whose terminal groups are vinyl ether and allyl ether in the solvent according to the ratio in the following table.

The curing system was coated on the salt sheet, dried with hot air to form a film, and placed on the horizontal sample stage of the real-time infrared spectrometer. Directly irradiate the sample with a point light source at room temperature, adjust the ultraviolet light intensity to 30mW/cm ² , and collect infrared data at the same time. Its aggregation is as follows:

Polymerization of the curing system initiated by the cationic initiator in table 1

P-1: Mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG201;

P-2: mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG202;

P-3: triaryl sulfonium fluoroantimonate cationic photoinitiator 445;

P-4: free radical initiator ITX;

P-5: free radical initiator 907;

P-6: free radical initiator 784;

P-7: free radical initiator TPO;

P-8: Free radical initiator BAPO.

It can be seen from the table that the main function of the solvent is to dissolve the monomer and the initiator to make the final film uniform, so as long as the solvent with good volatility is sufficient; the concentration of the initiator accounts for 2.7% of the system. The mass of the initiator accounts for 3% of the total mass of the initiator and the monomer. At this time, the double bond of the vinyl ether is completely polymerized, and the allyl ether is partially polymerized.

The cationic photopolymerization initiator, the free radical photopolymerization initiator, and the photosensitive monomer whose end groups are vinyl ether and allyl ether are dissolved in the solvent according to the ratio shown in the table below.

Coat the curing system on the salt sheet, dry it with hot air to form a film, and put it on the horizontal sample stage of the real-time infrared spectrometer. At room temperature, a point light source was used to irradiate the sample in a directional manner, and the intensity of the ultraviolet light was adjusted to 30 mW/cm ² , while collecting infrared data. Its aggregation is as follows:

Table 2 Polymerization of the curing system under mixed photoinitiators.

P-1: Mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG201;

P-2: mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG202;

P-3: triaryl sulfonium fluoroantimonate cationic photoinitiator 445;

P-4: free radical initiator ITX;

P-5: free radical initiator 907;

P-6: free radical initiator 784;

P-7: free radical initiator TPO;

P-8: Free radical initiator BAPO.

It can be seen from Table 2 that after adding a free radical initiator, the degree of polymerization increases, and P-4 has the best effect, and the monomer can be completely polymerized when combined with a cationic initiator. Although the aggregation time increases, the aggregation rate is still relatively high.

The viscosity of the samples was measured with a capillary viscometer.

The polymerization rate and degree of polymerization of the monomers are measured by a real-time infrared instrument. That is to say, ultraviolet radiation and infrared detection are carried out on the sample at the same time. A high-energy ultraviolet light source with an emission wavelength of 365nm is used to irradiate the sample through an optical fiber in a directional manner, and the light intensity is 30mW/cm ² , which is measured by a light intensity meter. During the photopolymerization process, the data acquisition interval was 1.59s, and the acquisition resolution was 4cm ^-1 . By RT-FTIR technique, the changes of the characteristic peaks 1617cm ^-1 and 1647cm ^-1 of vinyl ether and allyl ether double bonds were monitored to obtain kinetic parameters such as degree of polymerization and polymerization rate. The characteristic peaks of the double bonds of vinyl ether and allyl ether overlap into one peak and cannot be separated due to their close aggregation. However, during the data and process, it can be seen from the infrared spectrum that as the exposure time increases, the 1616cm ^-1 gradually decreases, revealing the peak of 1647cm ^-1 . According to the detection of auxiliary characteristic peaks, under a single cationic initiator, the double bond of vinyl ether is completely polymerized, and the double bond of allyl ether is partially polymerized; under the mixed initiation of cationic initiator and free radical initiator, the two Both double bonds are fully polymerized.

Claims (5)

1. A composition of cationic polymerization or cationic-radical mixed polymerization of photopolymerization curing system, characterized in that, its specific composition is: (1) The end group of 86-89 parts by weight is a photosensitive monomer of vinyl ether and allyl ether; (2) The photopolymerization initiator of 1-4 weight part; (3) 7-13 parts by weight of solvent. 2. the composition of a kind of photopolymerization curing system of cationic polymerization or cationic-free radical mixed polymerization according to claim 1, described end group is the photosensitive monomer of vinyl ether and allyl ether as follows Show:

In the formula, R ₁ is a vinyl ether alkoxy group, and the structural formula is

Wherein R _is H, an alkyl or phenyl group with 1-4 carbon atoms, and a is an integer of 1-10; R ₂ is an allyl ether alkoxy group, and the structural formula is

Wherein R ₈ is H, and the number of carbon atoms is 1-4 alkyl or phenyl, b is an integer of 1-10; R ₃ , R ₄ , R ₅ , R ₆ are H, CH ₃ , phenyl or p-methylphenyl; n is an integer of 0-10; m is an integer of 1-10. 3. The composition of the photopolymerization curing system of a kind of cationic polymerization or cationic-free radical mixed polymerization according to claim 1, the specific structural formula of the photosensitive monomer of described end group is vinyl ether and allyl ether As follows: Monomers A-1 to A-24:

Monomers B-1 to B-24:

Monomers C-1 to C-24:

Monomers D-1 to D-24:

Monomers E-1 to E-24:

4. the composition of the photopolymerization curing system of a kind of cationic polymerization or cationic-radical mixed polymerization according to claim 2 or 3, described photopolymerization initiator is cationic photopolymerization initiator and free radical photopolymerization initiation agent, specifically mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG201, mixed triaryl sulfonium fluoroantimonate cationic photoinitiator PAG202, triaryl sulfonium fluoroantimonate cationic photoinitiator 445, One or more of free radical initiator ITX, free radical initiator 907, free radical initiator 784, free radical initiator TPO, free radical initiator BAPO. 5. the composition of the photopolymerization curing system of a kind of cationic polymerization or cationic-free radical mixed polymerization according to claim 4, described solvent is ethyl lactate, butyl acetate, pentyl acetate, ethyl pyruvate , ethylene glycol ethyl ether acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether acetate, acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone, γ-butyrolactone, cyclohexane, One or more of tetrahydrofuran.