Search

CN-121978254-A - OCA photocuring rate rapid characterization method

CN121978254ACN 121978254 ACN121978254 ACN 121978254ACN-121978254-A

Abstract

The invention relates to the technical field of material detection, in particular to a rapid characterization method of OCA photocuring rate. According to the quick characterization method of the OCA photocuring rate, the photocuring rate of the OCA can be dynamically monitored by testing the content and the change rate of the photoinitiator 651, the free radical quenching product benzil and the methyl benzoate in the OCA system and combining the conversion rate of the monomers, and in addition, the photocuring endpoint can be further obtained, so that the optimal curing time is obtained. The method can realize rapid and high-sensitivity characterization on the whole process of the curing reaction by monitoring the byproducts generated by self-quenching of the free radicals, does not need to use an organic solvent, and is safe and environment-friendly.

Inventors

  • HU ZHENLONG
  • WANG JIASHENG
  • LI MINGLIANG
  • CHEN JIEFANG

Assignees

  • 广州鹿山新材料股份有限公司
  • 广州鹿山先进材料有限公司
  • 广州鹿山兴邦光学材料有限公司

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. The quick characterization method of the OCA photocuring rate is characterized by comprising the following steps of: (a) Taking at least 2 parallel samples of OCA to be tested after curing, and naming the parallel samples as first samples, and continuing the photo-curing treatment of the 1 first samples for t time to obtain second samples, wherein t is 5-10 s; (b) Performing Py-GC/MS test on the first sample and the second sample to obtain a total ion flow diagram and an m/z 77 ion flow diagram, normalizing the m/z 77 ion flow diagram of the second sample by using the peak area of 2, 6-di-tert-butyl-p-cresol in the m/z 77 ion flow diagram of the first sample, then obtaining the peak area of methyl benzoate, the peak area of benzil and the peak area of a photoinitiator 651 in the m/z 77 ion flow diagram of the second sample after normalization, and calculating a byproduct conversion rate Tr; Wherein tr= 、 、 The peak area of the photoinitiator 651, the peak area of methyl benzoate and the peak area of benzil in the m/z 77 ion flow diagram of the first sample; 、 、 the peak area of the photoinitiator 651, the peak area of methyl benzoate and the peak area of benzil in the m/z 77 ion flow diagram of the second sample after normalization treatment; Obtaining the photo-curing rate R of the cured OCA to be tested according to Tr; if Tr is more than or equal to 0.1% and less than or equal to 25%, obtaining the peak area of each monomer in the total ion flow diagram of the first sample, and calculating the photo-curing rate R of the cured OCA to be tested; wherein r= The OCA to be measured contains n monomers, A i is the peak area of the monomers, C i is the response factor of the monomers, The peak area of the 2, 6-di-tert-butyl-p-cresol in an m/z 77 ion flow diagram of the first sample is represented by S, wherein S is the mass percentage of the 2, 6-di-tert-butyl-p-cresol in the OCA to be detected; If Tr is 25% or less and Tr is less than 40%, calculating the light curing rate R of the cured OCA to be tested according to the following formula: Tr=59.376×R 3 – 186.73×R 2 + 195.5×R – 67.754 If Tr is 40% or less and is less than 45%, the photo-curing rate of the cured OCA to be tested is 100%; The OCA to be tested comprises a photo-curable monomer, a photoinitiator 651 and 2, 6-di-tert-butyl-p-cresol, wherein the content of the photoinitiator 651 is 0.5-3 wt%; in the Py-GC/MS test, the thermal cracking temperature is 280-300 ℃.
  2. 2. The method for rapidly characterizing the photo-curing rate of an OCA according to claim 1, further comprising taking at least 2 first samples and continuing the photo-curing process for 2t and 3t periods to obtain a third sample and a fourth sample, respectively; Carrying out Py-GC/MS test on the third sample and the fourth sample to obtain a total ion flow diagram and an m/z 77 ion flow diagram, carrying out normalization treatment on the m/z 77 ion flow diagrams of the third sample and the fourth sample according to the peak areas of the 2, 6-di-tert-butyl-p-cresol in the m/z 77 ion flow diagram of the first sample, and then respectively obtaining the peak areas of methyl benzoate, the peak areas of benzil and the peak areas of a photoinitiator 651 in the m/z 77 ion flow diagrams of the third sample and the fourth sample after normalization treatment, and calculating byproduct conversion rates Tr ' and Tr ' '; Wherein Tr' = ,Tr’’= , 、 、 The peak area of the photoinitiator 651, the peak area of methyl benzoate and the peak area of benzil in the m/z 77 ion flow diagram of the third sample after normalization treatment; 、 、 The peak area of the photoinitiator 651, the peak area of methyl benzoate and the peak area of benzil in the m/z 77 ion flow diagram of the fourth sample after normalization treatment; when Tr 'and Tr' 'are met, tr' is 40% -45%, tr '=Tr' 'is 40% -45%, the curing time t' tot '+t of the OCA to be detected is taken as a photocuring end point, and t' is the cured time of the first sample.
  3. 3. The method for rapidly characterizing the photo-curing rate of an OCA according to claim 1, wherein the content of 2, 6-di-tert-butyl-p-cresol in the OCA to be tested is 0.1wt% to 0.5wt%.
  4. 4. The method for rapidly characterizing the photo-curing rate of OCA according to claim 1, wherein the photo-curable monomer comprises at least one of butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, isobornyl acrylate, and dimethylacrylamide.
  5. 5. The method according to claim 4, wherein the butyl acrylate has a response factor of 2.9, the isooctyl acrylate has a response factor of 2.9, the hydroxyethyl acrylate has a response factor of 2.9, the hydroxypropyl acrylate has a response factor of 1.8, the isobornyl acrylate has a response factor of 1.9, and the dimethylacrylamide has a response factor of 3.
  6. 6. The method for rapid characterization of OCA photocuring according to claim 1, wherein the irradiation intensity in the photocuring treatment is the same as the irradiation intensity adopted by the cured OCA to be tested.
  7. 7. The method for rapidly characterizing the photo-curing rate of an OCA according to claim 6, wherein the irradiation intensity is 12-14 mw/cm 2 .
  8. 8. The method for rapidly characterizing the photo-curing rate of OCA according to claim 1, wherein the cleavage time is 10-30 s in the Py-GC/MS test.
  9. 9. The method for rapidly characterizing the OCA photocuring rate according to claim 1, wherein in the Py-GC/MS test, a chromatographic column model is HP-5MS, a split ratio is (100-200): 1, an interface temperature is 280-300 ℃, and a front sample inlet temperature is 280-300 ℃; the GC temperature program was such that after 2min of retention at 40℃the temperature was raised to 300℃at 20℃/min and then 10min of retention at 300 ℃.
  10. 10. The method for rapidly characterizing the photo-curing rate of OCA according to claim 1, wherein in the m/z 77 ion flow graph, the retention time of 2, 6-di-t-butyl-p-cresol is 9.895min±0.1min, the retention time of methyl benzoate is 6.881min±0.1min, the retention time of benzil is 11.711min±0.1min, and the retention time of photoinitiator 651 is 12.044min±0.1min.

Description

OCA photocuring rate rapid characterization method Technical Field The invention relates to the technical field of material detection, in particular to a rapid characterization method of OCA photocuring rate. Background The Optically Clear Adhesive (OCA) has wide application in flexible display devices, the ultraviolet curing technology becomes the most common curing mode in OCA synthesis due to the high-efficiency and environment-friendly characteristics, and the light curing rate is a key index for measuring the quality of products. The photo-curing rate is closely related to the properties such as peel strength, weather resistance and the like. The accurate photo-cure rate test can evaluate the adhesion of the OCA to the substrate and prevent the substrate resin from aging due to debonding caused by undercure or excessive curing. The current industry mainly adopts traditional characterization methods such as a viscosity method, a thermal analysis method, a hardness method, a chemical solvent extraction solid content method and the like to test the photocuring rate. Although these methods are relatively mature, they generally rely on indirect evaluation of changes in macroscopic physical properties, and it is often difficult to achieve high-precision measurements in the later stages of photocuring (particularly in stages with photocuring rates higher than 95%), and there are certain limitations. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a rapid characterization method of OCA photocuring rate, which can realize rapid and high-sensitivity characterization of the whole curing reaction process by monitoring byproducts generated by self quenching of free radicals, and is safe and environment-friendly without using an organic solvent. In order to achieve the above object, the present invention provides a method for rapidly characterizing the photo-curing rate of OCA, comprising the steps of: (a) Taking at least 2 parallel samples of OCA to be tested after curing, and naming the parallel samples as first samples, and continuing the photo-curing treatment of the 1 first samples for t time to obtain second samples, wherein t is 5-10 s; (b) Performing Py-GC/MS test on the first sample and the second sample to obtain a total ion flow diagram and an m/z 77 ion flow diagram, normalizing the m/z 77 ion flow diagram of the second sample by using the peak area of 2, 6-di-tert-butyl-p-cresol in the m/z 77 ion flow diagram of the first sample, then obtaining the peak area of methyl benzoate, the peak area of benzil and the peak area of a photoinitiator 651 in the m/z 77 ion flow diagram of the second sample after normalization, and calculating a byproduct conversion rate Tr; Wherein tr= 、、The peak area of the photoinitiator 651, the peak area of methyl benzoate and the peak area of benzil in the m/z 77 ion flow diagram of the first sample;、、 the peak area of the photoinitiator 651, the peak area of methyl benzoate and the peak area of benzil in the m/z 77 ion flow diagram of the second sample after normalization treatment; Obtaining the photo-curing rate R of the cured OCA to be tested according to Tr; if Tr is more than or equal to 0.1% and less than or equal to 25%, obtaining the peak area of each monomer in the total ion flow diagram of the first sample, and calculating the photo-curing rate R of the cured OCA to be tested; wherein r= The OCA to be measured contains n monomers, A i is the peak area of the monomers, C i is the response factor of the monomers,The peak area of the 2, 6-di-tert-butyl-p-cresol in an m/z 77 ion flow diagram of the first sample is represented by S, wherein S is the mass percentage of the 2, 6-di-tert-butyl-p-cresol in the OCA to be detected; If Tr is 25% or less and Tr is less than 40%, calculating the light curing rate R of the cured OCA to be tested according to the following formula: Tr=59.376×R3– 186.73×R2+ 195.5×R – 67.754 If Tr is 40% or less and is less than 45%, the photo-curing rate of the cured OCA to be tested is 100%; The OCA to be tested comprises a photo-curable monomer, a photoinitiator 651 and 2, 6-di-tert-butyl-p-cresol, wherein the content of the photoinitiator 651 is 0.5-3 wt%; in the Py-GC/MS test, the thermal cracking temperature is 280-300 ℃. In a specific embodiment of the invention, the characterization method further comprises the steps of taking at least 2 first samples, and respectively continuing the photo-curing treatment for 2t time periods and 3t time periods to obtain a third sample and a fourth sample; Carrying out Py-GC/MS test on the third sample and the fourth sample to obtain a total ion flow diagram and an m/z 77 ion flow diagram, carrying out normalization treatment on the m/z 77 ion flow diagrams of the third sample and the fourth sample according to the peak areas of the 2, 6-di-tert-butyl-p-cresol in the m/z 77 ion flow diagram of the first sample, and then respectively obtaining the pea