Photocurable composition and use thereof

Abstract

The present application provides a photocurable composition and a use thereof. The composition comprises the following components: (a) at least one benzoylformate compound; and (b) at least one ethylenically unsaturated photopolymerizable compound, wherein the benzoylformate compound is formed by reacting a compound represented by general formula (I) with a compound represented by general formula (II) and a compound represented by general formula (III). The benzoylformate compound of the present application has excellent solubility, the sensitivity of the obtained product is not reduced compared with existing small-molecule sensitivity, and the hardness of the product is improved under LED curing.

Description

A photocurable composition and its application Technical Field

[0001] This application belongs to the field of photocuring, and specifically relates to a photocurable composition and its application. Background Technology

[0002] Benzoyl carbamate photoinitiators are common free radical photoinitiators. Due to their simple structure, ease of synthesis, and low price, they are very commonly used photoinitiators. However, problems such as migration, odor, yellowing, and solubility often exist during use, which greatly limits their application. Chinese patents CN102442909A and CN101979373A have macromolecularized benzoyl carbamate photoinitiators, which has solved the odor and migration problems to some extent. However, the initiation efficiency is reduced, and cost is also a factor to consider.

[0003] However, while improving the solubility and post-curing migration of initiator products, minimizing the impact on initiation efficiency has always been a goal, especially under LED curing. Ensuring the existing initiation efficiency while maintaining the product's application performance is also a problem that needs to be solved. Summary of the Invention

[0004] This application provides a photocurable composition and its application. The photocurable composition of this application exhibits good compatibility after application, shows no migration, has minimal impact on initiation efficiency, and is low in cost. Under LED curing, the initiation efficiency is unaffected while the hardness of the product is improved.

[0005] On one hand, this application provides a photocurable composition comprising the following components:

[0006] (a) at least one benzoyl carbamate compound;

[0007] (b) at least one olefinically unsaturated photopolymerizable compound;

[0008] The benzoyl carbamate compound is formed by reacting the compound of general formula (I) with the compounds of general formula (II) and general formula (III):

[0009]

[0010] Where A is a single bond, O, S or CR2R3, and R2 and R3 are independent of each other, representing hydrogen, C1-C8 straight-chain or branched alkyl groups;

[0011] R1 and R1' are independently C1-C4 alkyl groups;

[0012] R a For hydrogen, -OH, C1-C80 Alkyl or the C1-C 80 An alkyl group in which at least one CH2 group is replaced by an oxygen or benzene ring, R b Indicates a straight-chain or branched alkylene group of C1-C8 atoms;

[0013] q is an integer from 1 to 20 (e.g., 1, 2, 3, 5, 8, 10, 12, 14, 16, 18, or 20, etc.), and p is an integer from 2 to 10 (e.g., 2, 3, 4, 5, 8, 10, 11, 12, 14, 16, 18, or 20, etc.); when q is greater than 2, multiple R b Same or different;

[0014] R4 represents hydrogen, C1-C 10 Straight-chain or branched alkyl groups;

[0015] R5 and R6 independently represent hydrogen, C1-C 10 It consists of straight-chain or branched alkyl groups, with R5 and R6 existing alone or linked together to form a ring.

[0016] In this application, the range of carbon atoms defined in the group definition indicates that the number of carbon atoms in the defined group can be any value within the defined range. For example, C1-C8 means that the number of carbon atoms can be 1, 2, 3, 4, 5, 6, 7 or 8. 20 The number of carbon atoms can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, and so on.

[0017] Preferably, in the structure described in formula (II), R a Selected from the following groups:

[0018]

[0019] Preferably, R b Selected from -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH(CH3)-CH2- or -CH2-CH(CH3)-CH2-.

[0020] In some embodiments, the compound represented by general formula (II) is selected from polyethylene glycol, polypropylene glycol, and or , where x, y, z are each independently selected from integers from 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10), and the sum of x, y, z is 3 to 12, preferably, the sum of x, y, z is 6 to 12 (e.g., 6, 7, 8, 9, 10, 11 or 12).

[0021] More preferably, the benzoyl carbamate compound is obtained by reacting the compounds of formula (I) and formula (II) first, and then capping it with the compound of formula (III).

[0022] Further, the benzoyl carbamate compound preferably has a number average molecular weight of 500-50000, for example 500, 800, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 6000, 8000, 10000, 13000, 15000, 18000, 20000, 23000, 25000, 30000, 35000, 40000, 45000, or 50000.

[0023] Furthermore, the compound represented by general formula (III) is selected from any one of the following compounds:

[0024] Furthermore, in this application, initiators of compounds or mixtures with different structures are obtained according to the different proportions and raw materials of compounds of formula (I), formula (II) and formula (III).

[0025] The preparation method of the benzoyl carbamate compound provided in this application is not particularly limited. Different suitable preparation methods can be selected according to different raw materials (II). After reacting the compound of general formula (I) and the compound of general formula (II) to obtain an intermediate, the intermediate is further reacted with the compound of formula (III) to obtain the benzoyl carbamate compound.

[0026] Preferably, the molar ratio of hydroxyl groups in the compound of general formula (I) and the compound of general formula (II) is 1:1.05-6:1, for example 1:1.05, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1 or 6:1.

[0027] Preferably, the reaction of the compound represented by general formula (I) and the compound represented by general formula (II) is carried out under weakly basic conditions.

[0028] Preferably, the reaction temperature of the compound represented by general formula (I) and the compound represented by general formula (II) is 80-180°C (e.g., 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C), and the reaction time is 4-12h (e.g., 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h or 12h).

[0029] In this application, the reaction between the compound represented by general formula (I) and the compound represented by general formula (II) may or may not involve the addition of a solvent. There is no particular limitation on the type of solvent used, as long as it can dissolve the reactants and has no adverse effect on the reaction. Preferably, the solvent for the reaction is selected from any one or a combination of at least two of xylene, m-dichlorobenzene, or N,N-dimethylformamide.

[0030] Preferably, the molar ratio of the ester group in the intermediate and the compound of general formula (III) is 1:1.05-6:1, for example 1:1.05, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1 or 6:1.

[0031] Preferably, the reaction between the intermediate and the compound of general formula (III) is carried out under weakly alkaline conditions.

[0032] Preferably, the reaction temperature of the intermediate and the compound represented by general formula (III) is 80-180°C (e.g., 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C), and the reaction time is 4-12 h (e.g., 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h or 12 h).

[0033] Preferably, the olefinically unsaturated photopolymerizable compound is selected from compounds having one or more olefinic double bonds, olefinically unsaturated carboxylic acids, unsaturated carboxylic acid esters, unsaturated polyols, or polyepoxides.

[0034] Preferably, the alkyl ester unsaturated photopolymerizable compound is selected from alkyl acrylates, alkyl methacrylates, hydroxyalkyl esters, alkyl epoxy esters, (meth)acrylamide, N-substituted (meth)acrylamide, unsaturated carboxylic anhydrides, unsaturated esters, vinyl ethers, isocyanurates, N-vinyl heterocyclic compounds, acrylic acid, methacrylic acid, and unsaturated fatty acids such as linolenic acid or oleic acid.

[0035] Preferably, the unsaturated carboxylic acid is acrylic acid or methacrylic acid.

[0036] Preferably, the unsaturated polyol may be an aromatic, aliphatic, or cycloaliphatic polyol. Examples of aromatic polyols include hydroquinone, 4,4-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane, linear phenolic resins, or A-stage phenolic resins.

[0037] In another aspect of this application, the olefinically unsaturated photopolymerizable compound is an acrylated epoxy resin, an alkyl acrylate, an alkoxy acrylate, or a mixture thereof, most preferably an epoxy acrylate, a trimethylolpropane triacrylate, or a mixture thereof.

[0038] Preferably, component (a) in the photocurable composition accounts for 0.5-10% of the weight of the composition, for example, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0039] Preferably, component (a) in the photocurable composition accounts for 3-5% of the weight of the composition.

[0040] In this application, component (b) of the photocurable composition accounts for 2-99.5% of the weight of the composition, such as 2%, 5%, 8%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 90%, 95%, etc., preferably 30-99.5%, more preferably 60-99.5%, and even more preferably 90-99.5%.

[0041] The photocurable compositions of this application may also selectively contain commonly used organic and / or inorganic additives (c) in the art, including but not limited to pigments, leveling agents, dispersants, curing agents, surfactants, or solvents, which will be apparent to those skilled in the art. Furthermore, sensitizers may also be added to the compositions for compound use, provided that they do not negatively impact the application effect of the compositions.

[0042] In addition to components (a), (b) and (c), the photocurable composition described in this application may also contain other photoinitiators (d).

[0043] On the other hand, this application also provides the use of the photocurable compositions described above in coatings, inks, adhesives or photoresists.

[0044] Compared with the prior art, this application has the following advantages:

[0045] The benzoyl carbamate compound of this application has excellent solubility, and the sensitivity of the photocurable composition containing it is not reduced compared to the sensitivity of existing small molecules. Furthermore, the hardness of the product is improved under LED curing. Detailed Implementation

[0046] The technical solution of this application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely to help understand this application and should not be regarded as specific limitations on this application.

[0047] Preparation Examples

[0048] Example 1

[0049]

[0050] 35g of compound (1a), 60g of polyethylene glycol-300 (1b), and 1g of potassium acetate were added to a 250mL single-necked flask. After mixing evenly, the system was heated. When the external temperature reached 90℃, stirring was started and the system was evacuated. When the pressure dropped to -0.095MPa, the external temperature was maintained at 90℃ and stirred for 2h. After the heat preservation was completed, nitrogen gas was released and 10g of ethyl 4-diethylaminobenzoate (1c) was added to further increase the system vacuum to 200~300Pa. The external temperature was maintained at 90℃ and the reaction was continued with stirring. The reaction was monitored by GPC. When the weight average molecular weight of the product was >1000, the reaction was stopped. The system was cooled to room temperature, and 1g of activated carbon was added to the reaction solution and stirred for 2h. After filtration, 95.0g of viscous yellow liquid (compound 1) was obtained, and the weight average molecular weight was measured to be 2246.

[0051] Example 2

[0052]

[0053] 34 g of compound (2a), 60 g of polypropylene glycol-300 (2b), and 1 g of potassium acetate were added to a 250 mL single-necked flask. After mixing evenly, the system was heated. When the external temperature reached 90 °C, stirring was started and the system was evacuated. When the pressure dropped to -0.095 MPa, the external temperature was maintained at 90 °C and stirred for 2 h. After the heat preservation was completed, nitrogen gas was released and 9.5 g of ethyl 4-dimethylaminobenzoate (2c) was added to further increase the vacuum of the system to 200~300 Pa. The external temperature was maintained at 90 °C and the reaction was continued with stirring. The reaction was monitored by GPC. When the weight average molecular weight of the product was >1000, the reaction was stopped. The system was cooled to room temperature, and 1 g of activated carbon was added to the reaction solution and stirred for 2 h. After filtration, 93.0 g of viscous yellow liquid (compound 2) was obtained, and the weight average molecular weight was measured to be 2136.

[0054] Example 3

[0055]

[0056] 20 g of compound (2a), 30.77 g of TMP-9EO (weight-average molecular weight 530), 43.14 g of ethyl 4-dimethylaminobenzoate (2c), and 1 g of potassium acetate were added to a 250 mL single-necked flask. After mixing thoroughly, the system was heated. When the external temperature reached 110 °C, stirring was started, and the system was evacuated. When the pressure dropped to -0.095 MPa, the external temperature was maintained at 90 °C and stirred for 2 h. The reaction was monitored by GPC. When the weight-average molecular weight of the product was >1000, the reaction was stopped. The system was cooled to room temperature, and 1 g of activated carbon was added to the reaction solution and stirred for 2 h. After filtration, 83.5 g of a viscous yellow liquid (compound 3) was obtained, and the weight-average molecular weight was measured to be 2801.

[0057] Example 4-12

[0058] By changing different raw materials according to the synthesis method described in Example 1 or 2, polymers with different structures and molecular weights as shown in Table 1 were obtained.

[0059]

[0060]

[0061] Performance Evaluation

[0062] The application performance of the initiator of this application was evaluated by formulating exemplary photocurable compositions (i.e., photosensitive resin compositions, parts by weight).

[0063]

[0064] E201: Bisphenol A epoxy acrylate (Changzhou Qiangli Electronic New Materials Co., Ltd.)

[0065] ACMO: Acryloylmorpholine (Runao Chemical)

[0066] TMPTA: Trimethylolpropane triacrylate

[0067] PEGDA: Polyethylene glycol diacrylate

[0068] BYK307: Leveling agent (BYK Chemicals, Germany)

[0069] Initiator A: [4-(4-methoxyoxaloyl-phenylthioalkyl)-phenyl]-oxo-acetic acid methyl ester

[0070] Initiator B: 2-(9,9-dimethoxyxanthone-2-yl)-2-oxo-ethyl acetate

[0071] Initiator C: Initiator MBF

[0072] Initiator D: Initiator 754.

[0073] 2. Performance Evaluation Methods

[0074] (1) Solubility evaluation

[0075] The solubility of initiator A: [4-(4-methoxyoxalyl-phenylthioalkyl)-phenyl]-oxo-acetic acid methyl ester (IGM), initiator B: 2-(9,9-dimethoxyxanthan-2-yl)-2-oxo-ethyl acetate (IGM), and the compound provided in the examples in propylene glycol methyl ether acetate was tested, and the results are shown in Table 3 below.

[0076] The solubility test method is as follows: At room temperature (20±0.5℃), add an appropriate amount of 6110:TMPTA = 1:1 (mass ratio) photocurable monomer as a solvent to a 250mL glass beaker. Add 0.5g of the test sample to the solvent and stir for 20min. Visually observe whether there is any undissolved sample. If it dissolves completely, continue to add 0.5g of the test sample and stir for 20min until insoluble matter is present. Stop adding the sample, record the data, and calculate the sample solubility according to the following formula:

[0077]

[0078]

[0079] (2) Evaluation of curing performance

[0080] The photocurable composition was stirred and mixed under an LED (405nm light source) lamp, and then rolled onto a PET template to form a film with a thickness of approximately 50μm. A mercury lamp (100%, 1m / min, 1140mJ / cm²) was used. 2 Expose the image under light and observe the curing process of the composition. Evaluate the photosensitivity according to the following standards:

[0081] 1. Oil, not solid

[0082] 2. Surface oil, base layer cured.

[0083] 3. The surface is sticky, and fingerprints are easily left on the skin after touching it.

[0084] 4. Basically dry, slightly rough to the touch, faint fingerprints.

[0085] 5. Fully cured, smooth surface, no fingerprints after touching.

[0086] The hardness of the cured film after curing was evaluated according to Method B of GB / T 6739-1996 standard:

[0087] The test results are shown in Table 4:

[0088]

[0089] The compositions of Comparative Examples 3 and 4 did not meet the absorption wavelength requirements of the light source, did not cure, and could not be evaluated.

[0090] (3) Transferability testing

[0091] Using ethanol as a solvent, the initiator was prepared into 1×10⁻⁶ solutions. -5 The maximum absorption wavelength and absorbance A1 of the mol / L solution were measured using a UV3010 ultraviolet spectrophotometer, and the molar extinction coefficient was calculated using formula (1):

[0092] Formula (1): c = A / ε × b

[0093] Formula (2): R = 100 × c / c1

[0094] Using the formulations of the evaluation examples and comparative example 1 in Table 1-2, after thorough curing, 0.05 g of the above photocurable composition was weighed and fully cured under a high-pressure mercury lamp to obtain a cured film. Each film was immersed in 30 g of ethanol and left at room temperature for 24 h. The absorbance A2 at the maximum absorption wavelength was measured using an ultraviolet spectrophotometer with the same volume of the immersion solution. The concentration of the photoinitiator migrating from the three cured films was calculated using formula (1). Using the concentration value of photoinitiator (1) as a reference, the relative migration rate of each photoinitiator was calculated using formula (2).

[0095] In the above formula, c is the relative concentration (mol / L), c1 is the relative concentration of photoinitiator (1), A is the absorbance, ε is the molar absorptivity (L / mol·cm), b is the sample cell thickness (cm), and R is the relative mobility. The test results are shown in Table 5.

[0096]

[0097] Experiments show that the initiator of this application does not migrate and has high initiation efficiency. In particular, the initiation efficiency is basically unaffected when the molecular weight is increased. The hardness of the cured product is significantly improved compared with existing initiators, and it has the characteristics of low migration.

[0098] The applicant declares that this application illustrates the photocurable composition and its application through the above embodiments, but this application is not limited to the above embodiments, that is, it does not mean that this application must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this application, equivalent substitutions of the raw materials of the product, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this application.

Claims

1. A photocurable composition comprising the following components: (a) at least one benzoyl carbamate compound; (b) at least one olefinically unsaturated photopolymerizable compound; The benzoyl carbamate compound is formed by reacting the compound of general formula (I) with the compound of general formula (II) and the compound of general formula (III): ;in, A is a single bond, O, S, or CR2R3; R2 and R3 independently represent hydrogen, C1-C8 straight-chain or branched alkyl groups; R1 and R1' independently represent C1-C4 alkyl groups; R a For hydrogen, -OH, C1-C 80 Alkyl or the C1-C 80 An alkyl group in which at least one CH2 group is replaced by an oxygen or benzene ring, R b Represents a C1-C8 straight-chain or branched alkylene group; q is an integer from 1 to 20, and p is an integer from 1 to 10; when q is greater than 2, multiple R... b Same or different; R4 represents hydrogen, C1-C 10 Straight-chain or branched alkyl groups; R5 and R6 independently represent hydrogen, C1-C 10 It consists of straight-chain or branched alkyl groups, with R5 and R6 existing alone or linked together to form a ring.

2.

3. The photocurable composition according to claim 1, wherein, R b Selected from -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH(CH3)-CH2-, -CH2-CH(CH3)-CH2-; Preferably, the compound represented by general formula (II) is selected from polyethylene glycol, polypropylene glycol, and polybutanediol. or , where x, y, and z are each independently selected from integers from 1 to 10, and the sum of x, y, and z is 3 to 12, preferably 6 to 12.

4. The photocurable composition according to claim 1, wherein, The benzoyl carbamate compound is obtained by reacting the compounds of formula (I) and formula (II) with the compound of formula (III) for further end-capping.

5. The photocurable composition according to any one of claims 1-4, wherein, The number average molecular weight of the benzoyl carbamate compound is 500-50000, preferably 1000-10000.

6. The photocurable composition according to any one of claims 1-5, wherein, The terminating substituent compound is selected from...

7. The photocurable composition according to any one of claims 1-6, wherein, In the photocurable composition, component (a) accounts for 0.5-10% of the weight of the composition.

8. The photocurable composition according to any one of claims 1-7, wherein, In the photocurable composition, component (a) accounts for 3-5% of the weight of the composition.

9. The photocurable composition according to any one of claims 1-8, wherein, The photocurable composition also includes other additives (c) and / or other photoinitiators (d).

10. The use of the photocurable composition according to any one of claims 1-9 in coatings, inks, adhesives or photoresists.

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