Delayed UV curing packaging adhesive for OLED display panel, OLED display panel and manufacturing method of OLED display panel

Abstract

The invention provides a delayed UV curing packaging adhesive for an OLED (Organic Light Emitting Diode) display panel, the OLED display panel and a manufacturing method of the OLED display panel. The delayed UV curing packaging adhesive for the OLED display panel comprises the following components in parts by weight: 40-70 parts of glycidyl ether epoxy resin; 1 to 10 parts of oxetane resin; 30 to 50 parts of a nano-scale filling material; 0.1 to 1 part of a defoaming agent; 0.1 to 2 parts of a photoinitiator; 0.1 to 2 parts of a dispersant; 0.1 to 5 parts of PS (polystyrene) microspheres; and 0.1-1 part of an organic delayed curing agent. The organic delayed curing agent is used for reducing the viscosity of the delayed UV curing packaging adhesive for the OLED display panel after UV pre-curing, so that the viscosity of the delayed UV curing packaging adhesive for the OLED display panel after UV pre-curing operation in the pressing and fixing operation process is 400 P.S to 1600 P.S. The delayed UV curing packaging adhesive for the OLED display panel not only can prevent external water, oxygen or pollutants from entering the box dam structure, but also can prevent the fill adhesive from overflowing from the box dam structure.

Description

Technical Field

[0001] This disclosure relates to the technical field of OLED display panel manufacturing processes, and in particular to a delayed UV curing encapsulant for OLED display panels, an OLED display panel, and a method for manufacturing an OLED display panel. Background Technology

[0002] With continuous breakthroughs in display technology, OLED display panels, thanks to their self-emissive characteristics, exhibit advantages unmatched by traditional LCD display panels—such as higher contrast, wider color gamut, faster response time, and greater flexibility in form (supporting bending and folding). Therefore, they are gradually becoming the mainstream product in the display market. At the same time, consumers' demands for the viewing experience of movies and games are constantly increasing, further driving the development of OLED display panels towards larger sizes.

[0003] Currently, OLED display panels on the market generally consist of an OLED display substrate and a glass plate, which are bonded together using filler adhesive. The organic materials of the light-emitting layer of the OLED display substrate have very high requirements. Furthermore, the organic components of the OLED display substrate are highly sensitive to moisture, oxygen, and potential atmospheric pollutants; they cannot be contaminated or corroded by water or oxygen. If the organic components of the OLED display substrate are contaminated or corroded by water or oxygen, it will directly shorten the lifespan of the OLED display panel. Therefore, a layer of encapsulating adhesive is generally applied to protect the organic materials, forming a "wall" structure at the edges of the OLED display substrate. This allows the encapsulating adhesive to effectively seal the gaps between the OLED display substrate and the glass plate after bonding, protecting the organic materials of the OLED display substrate and isolating them from water, oxygen, and other pollutants, thus extending the lifespan of the OLED panel. DAM adhesive (also known as damming adhesive) is a type of encapsulating adhesive that effectively prevents water, oxygen, and pollutants from penetrating the organic materials. Currently, the industry generally adopts a co-encapsulation scheme of "DAM adhesive (damming adhesive) + fill adhesive (filler adhesive)" to protect organic materials. Among them, although the fill adhesive has excellent leveling properties and can uniformly fill gaps, it is easy to spread to non-dotted areas. Therefore, it is necessary to rely on DAM adhesive to build a dam structure to limit its flow range.

[0004] However, the DAM adhesive currently used in OLED display panels has the following defects: On the one hand, it is prone to deformation and collapse when applied to the OLED display substrate; on the other hand, during the lamination process between the OLED display substrate and the glass plate, the high viscosity of the DAM adhesive can easily lead to abnormal lamination, resulting in gaps between the DAM adhesive and the glass plate. These gaps not only allow external water, oxygen, and contaminants to easily penetrate into the dam structure formed by the DAM adhesive, but also cause filler adhesive to overflow from the dam structure. In severe cases, effective lamination may even be impossible, requiring rework, which greatly reduces the production quality and efficiency of OLED display panels. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a delayed UV curing encapsulant for OLED display panels, an OLED display panel, and a method for manufacturing the OLED display panel, which can effectively press and fix the OLED display substrate and the glass plate together.

[0006] The purpose of this disclosure is achieved through the following technical solution:

[0007] A delayed UV-curable encapsulant for OLED display panels, used to construct dam structures on OLED display substrates, comprising the following mass fractions:

[0008]

[0009] The organic delayed curing agent is synthesized via the following synthetic pathway:

[0010]

[0011] R1 is isoflurone diisocyanate;

[0012] R2 is polycarbonate diol;

[0013] R3 is an oxobutane resin;

[0014] R4 is an intermediate compound;

[0015] The organic delayed curing agent is used to absorb the photoinitiator to generate proton acid during the UV pre-curing operation, thereby delaying the curing of the delayed UV curing encapsulant for OLED display panels;

[0016] The organic delayed curing agent is used to reduce the viscosity of the delayed UV curing encapsulant for the OLED display panel after UV pre-curing, so that the viscosity of the delayed UV curing encapsulant for the OLED display panel after UV pre-curing is 400 P·S to 1600 P·S during the pressing and fixing operation of the OLED display substrate and the glass plate.

[0017] In one embodiment, the viscosity of the delayed UV-curing encapsulant for the OLED display panel after the UV pre-curing operation is 400 P·S to 1600 P·S, and the duration is 20 min.

[0018] In one embodiment, the glycidyl ether epoxy resin is one of the following compounds:

[0019]

[0020] In one embodiment, R3 is compound B1-B. 10 At least one of the following:

[0021] .

[0022] In one embodiment, the photoinitiator is a thionium salt.

[0023] In one embodiment, the thioonium salt includes at least one selected from triarylthioonium salt, triphenylthioonium salt, diphenylmethylthioonium salt, bis(4-methoxyphenyl)thioonium salt, and tributylthioonium salt.

[0024] In one embodiment, the nanoscale filler includes at least one of nanoscale silica, nanoscale hydrotalcite, nanoscale talc, nanoscale montmorillonite, and nanoscale calcium carbonate.

[0025] In one embodiment, the defoamer is an organosilicone defoamer.

[0026] In one embodiment, the dispersant is the DISPERBYK-110 series.

[0027] In one embodiment, the PS microspheres are SBX series 10-micron PS microspheres.

[0028] In one embodiment, the method for synthesizing the organic delayed curing agent includes:

[0029] R1 and R2 are placed into the reactor at a preset mass ratio, and a catalyst is added;

[0030] The temperature inside the reactor is adjusted to 75℃~85℃ so that R1 and R2 react for 240min~300min to obtain R4;

[0031] After obtaining R4, R3 is continuously added to the reactor until the NCO groups of R4 are completely reacted to obtain the organic delayed curing agent R5.

[0032] In one embodiment, the catalyst is organotin dilaurate (DBTDL).

[0033] An OLED display panel includes an OLED display substrate and a glass plate. The delayed UV curable encapsulant for OLED display panels described in any of the above embodiments is used to construct the dam structure on the OLED display substrate to seal the gap between the OLED display substrate and the glass plate. The dam structure forms a dam sealing area, and filler adhesive between the OLED display substrate and the glass plate is applied to fill the dam sealing area.

[0034] A method for manufacturing an OLED display panel, used to manufacture the OLED display panel described in the above embodiments, the method comprising:

[0035] Obtain the prepared OLED display substrate;

[0036] The delayed UV curing encapsulant for OLED display panels is used to perform the first dispensing operation on the dispensing area of ​​the OLED display substrate in order to construct the dam structure on the OLED display substrate.

[0037] The filler adhesive is used to perform a second dispensing operation on the damming and sealing area of ​​the OLED display substrate, so that the filler adhesive fills the damming and sealing area;

[0038] The OLED display substrate, after completing the second dispensing operation, undergoes a UV pre-curing process; wherein the UV pre-curing temperature is 24.5℃-25.5℃, and the UV lamp power is 100mw / cm². 2 -110mw / cm 2 The energy is 1000 mJ / cm². 2 -1500mj / cm 2 ;

[0039] After completing the UV pre-curing operation, the OLED display substrate and the glass plate are pressed together so that the glass plate is sealed and covered at the opening of the dam structure, and together with the dam sealing area, they form a dam sealing cavity to seal the gap between the OLED display substrate and the glass plate, thus obtaining a semi-finished OLED display panel.

[0040] The OLED display panel semi-finished product is subjected to a complete curing operation to fully cure the delayed UV curing encapsulant and the filler for the OLED display panel, thereby obtaining the OLED display panel.

[0041] Compared with the prior art, this disclosure has at least the following advantages:

[0042] 1. The aforementioned delayed UV curing encapsulant for OLED display panels exhibits flexibility due to the rotatable single bonds and lack of conjugated systems within the oxygen heterocycle. Furthermore, the main chain of the organic delayed curing agent contains methylene (-CH2-) and ether (-O-) flexible units, effectively enhancing the overall flexibility of the delayed UV curing encapsulant for OLED display panels. Simultaneously, the PS microspheres, acting as elastic particles, effectively buffer and disperse the impact forces experienced by the delayed UV curing encapsulant, further improving its overall flexibility. This significantly reduces the probability of cracking during the lamination process, thereby greatly improving the production quality of OLED display panels.

[0043] 2. During the dispensing process onto the OLED display substrate using a dispensing machine, the delayed UV curing encapsulant for the OLED display panel is subjected to shear force. This causes the encapsulant, due to its high thixotropy, to exhibit low viscosity and flowability, precisely forming a dam structure. After the shear force on the encapsulant disappears (i.e., after the dispensing operation is completed), nanoscale fillers rapidly construct a three-dimensional physical cross-linked network. Combined with the high initial viscosity of glycidyl ether epoxy resin, this allows the delayed UV curing encapsulant for the OLED display panel to instantly lock its dispensing shape. This not only effectively suppresses the instantaneous deformation rate of the delayed UV curing encapsulant but also inhibits… The delayed UV curing encapsulant used in OLED display panels suffers from collapse and sagging due to gravity or surface tension. Meanwhile, oxetane resins and glycidyl ether epoxy resins can synergistically form an interpenetrating network, combined with the physical support of PS microspheres. The glycidyl ether epoxy resin provides rigid support, while the oxetane resin and PS microspheres provide flexible buffering through their elastic deformation capabilities. This collectively constructs a "rigid matrix + flexible buffer" composite structure, effectively preventing the dam structure built with the delayed UV curing encapsulant for OLED display panels from deforming or collapsing within a certain period after dispensing. This effectively prevents filler from overflowing the dam structure, thus significantly improving the production quality of OLED display panels.

[0044] 3. During the UV pre-curing process, the photoinitiator generates protic acids, while the organic delayed curing agent contains urethane groups. The -NH- group of the urethane group can react with the protic acid (H+). + The -NH2 group combines to form a weak bond. + By absorbing proton acids, the concentration of proton acids is effectively reduced, thereby slowing down the ring-opening reaction rate of aliphatic epoxy resins and effectively delaying the curing process of delayed UV-curing encapsulants used in OLED display panels; simultaneously, the positively charged -NH2... + The group causes electrostatic repulsion between the organic delayed-curing agent molecules, effectively preventing agglomeration and reducing the viscosity of the delayed-UV curing encapsulant used in OLED display panels after UV pre-curing. Furthermore, because the NH bond adjacent to the urethane group is an ester group (-COO-) and an oxygen heterocycle, the steric hindrance formed by the ester group and the oxygen heterocycle inhibits intermolecular hydrogen bonding, reducing the density of hydrogen bonding and further lowering the viscosity of the delayed-UV curing encapsulant used in OLED display panels. Especially when combined with 0.1-1 parts of organic delayed-curing agent, the viscosity of the delayed-UV curing encapsulant used in OLED display panels after UV pre-curing is reduced to 400 P·s to 1600 P·s during the lamination and fixing process between the OLED display substrate and the glass plate, thus enabling OLED... The display substrate and glass plate can be effectively pressed and fixed, ensuring that both sides of the delayed UV curing encapsulant used in the OLED display panel can be reliably sealed and bonded to the OLED display substrate and glass plate through their own viscosity. This effectively reduces the occurrence of abnormal pressing or even failure to press between the OLED display substrate and glass plate. As a result, the dam structure can effectively seal and protect the filler and the organic materials of the OLED display substrate. It can not only effectively prevent external water, oxygen and pollutants from entering the interior of the dam structure, but also effectively prevent the filler from overflowing from the dam structure. At the same time, it greatly reduces the possibility of rework of the OLED display panel due to abnormal pressing or failure to press, thereby greatly improving the production quality and efficiency of the OLED display panel.

[0045] 4. Due to the -NH- group of the urethane ester group after UV pre-curing and its interaction with the protic acid (H) + The -NH2 group combines to form a weak bond. +It does not react at room temperature, thus preventing premature curing of the delayed UV curing encapsulant used in OLED display panels before lamination preparation and during lamination. This ensures that the viscosity of the delayed UV curing encapsulant for OLED display panels is 400 P·S to 1600 P·S during lamination, thereby greatly improving the stability of the delayed UV curing encapsulant used in OLED display panels. Furthermore, due to the -NH- group of the urethane group after UV pre-curing reacting with the protic acid (H... + The -NH2 group combines to form a weak bond. + When heated to the complete curing temperature, it can quickly decompose and release protic acid. The released protic acid can promote the rapid cross-linking and curing reaction of glycidyl ether epoxy resin and oxetane resin, so as to ensure the sealing and protection effect of the dam structure, thereby greatly improving the production quality of OLED display panels. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram illustrating the steps of a method for manufacturing an OLED display panel according to an embodiment;

[0048] Figure 2 This is a graph showing the curing rate analysis corresponding to different contents of organic delayed curing agents in Examples 1-11;

[0049] Figure 3 The viscosity analysis graphs after UV pre-curing are for different contents of organic delayed curing agents in Examples 1-11.

[0050] Figure 4 The graph shows the water vapor transmission rate analysis of the delayed UV curing encapsulant for OLED display panels after complete curing, corresponding to different contents of organic delayed curing agent in Examples 1-11.

[0051] Figure 5 for Figure 1 The diagram shows a physical flow chart of the manufacturing process for an OLED display panel.

[0052] Figure 6 This is a schematic diagram illustrating the delay principle of a delayed UV curing encapsulant for an OLED display panel, according to one embodiment.

[0053] Figure 7This is a schematic diagram of a dam structure formed after dispensing a delayed UV curing encapsulant for an OLED display panel, according to one embodiment.

[0054] Figure 8 This is a schematic diagram showing the distribution of delayed UV curing encapsulant used in OLED display panels on the OLED display panel. Detailed Implementation

[0055] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0056] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0058] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments:

[0059] One embodiment of the delayed UV curable encapsulant for OLED display panels is used to construct dam structures on an OLED display substrate, comprising the following mass fractions:

[0060] 40-70 parts glycidyl ether epoxy resin; 1-10 parts oxetine resin; 30-50 parts nano-filler; 0.1-1 part defoamer; 0.1-2 parts photoinitiator; 0.1-2 parts dispersant; 0.1-5 parts PS (polystyrene) microspheres; 0.1-1 part organic delayed curing agent;

[0061] The organic delayed-curing agent is synthesized via the following synthetic pathway:

[0062]

[0063] R1 is isoflurane diisocyanate; R2 is polycarbonate diol; R3 is oxocyclic butane resin; R4 is an intermediate synthetic compound. The organic delayed curing agent is used to absorb the photoinitiator during the UV pre-curing operation to generate protic acid, thereby delaying the curing of the delayed UV curing encapsulant for OLED display panels. The oxocyclic ring has rotatable single bonds and no conjugated system, giving it a certain degree of flexibility. Furthermore, the main chain of the organic delayed curing agent contains methylene (-CH2-) and ether bond (-O-) flexible units, effectively improving the overall flexibility of the delayed UV curing encapsulant for OLED display panels. At the same time, PS microspheres, as elastic particles, can effectively buffer and disperse the impact force received by the delayed UV curing encapsulant for OLED display panels, further improving the overall flexibility of the delayed UV curing encapsulant for OLED display panels. This greatly reduces the probability of cracking of the delayed UV curing encapsulant for OLED display panels during the pressing process, thereby significantly improving the production quality of OLED display panels.

[0064] Furthermore, during the dispensing process on the OLED display substrate using a dispensing machine, the delayed UV curing encapsulant for the OLED display panel is subjected to shear force. This causes the delayed UV curing encapsulant to exhibit low viscosity and flowability due to its high thixotropy, precisely forming a dam structure. After the shear force on the delayed UV curing encapsulant disappears (i.e., after the dispensing operation is completed), nanoscale fillers rapidly construct a three-dimensional physical cross-linked network. Combined with the high initial viscosity of glycidyl ether epoxy resin, this allows the delayed UV curing encapsulant for the OLED display panel to instantly lock its dispensing shape. This not only effectively suppresses the instantaneous deformation rate of the delayed UV curing encapsulant for the OLED display panel but also inhibits... This invention addresses the collapse and sagging issues of delayed UV curing encapsulants used in OLED display panels due to gravity or surface tension. Furthermore, oxetane resins and glycidyl ether epoxy resins synergistically form an interpenetrating network, combined with the physical support of PS microspheres. The glycidyl ether epoxy resin provides rigid support, while the oxetane resin and PS microspheres provide flexible buffering through their elastic deformation capabilities. This collectively constructs a "rigid matrix + flexible buffer" composite structure, effectively preventing deformation or collapse of the dam structure built with delayed UV curing encapsulants for OLED display panels within a certain period after dispensing. This effectively prevents filler adhesive from overflowing the dam structure, significantly improving the production quality of OLED display panels.

[0065] Furthermore, the organic delayed curing agent is used to reduce the viscosity of the delayed UV-curable encapsulant for OLED display panels after UV pre-curing, so that the viscosity of the delayed UV-curable encapsulant for OLED display panels after UV pre-curing is 400 P·s to 1600 P·s during the lamination and fixing operation of the OLED display substrate and the glass plate. During the UV pre-curing operation, the photoinitiator generates protic acid, while the organic delayed curing agent contains urethane groups. The -NH- of the urethane group can react with the protic acid (H... + The -NH2 group combines to form a weak bond. + By absorbing proton acids, the concentration of proton acids is effectively reduced, thereby slowing down the ring-opening reaction rate of aliphatic epoxy resins and effectively delaying the curing process of delayed UV-curing encapsulants used in OLED display panels; simultaneously, the positively charged -NH2... + The group causes electrostatic repulsion between the organic delayed-curing agent molecules, effectively preventing agglomeration and reducing the viscosity of the delayed-UV curing encapsulant used in OLED display panels after UV pre-curing. Furthermore, because the NH bond adjacent to the urethane group is an ester group (-COO-) and an oxygen heterocycle, the steric hindrance formed by the ester group and the oxygen heterocycle inhibits intermolecular hydrogen bonding, reducing the density of hydrogen bonding and further lowering the viscosity of the delayed-UV curing encapsulant used in OLED display panels. Especially when combined with 0.1-1 parts of organic delayed-curing agent, the viscosity of the delayed-UV curing encapsulant used in OLED display panels after UV pre-curing is reduced to 400 P·s to 1600 P·s during the lamination and fixing process between the OLED display substrate and the glass plate, thus enabling OLED... The display substrate and glass plate can be effectively pressed and fixed, ensuring that both sides of the delayed UV curing encapsulant used in the OLED display panel can be reliably sealed and bonded to the OLED display substrate and glass plate through their own viscosity. This effectively reduces the occurrence of abnormal pressing or even failure to press between the OLED display substrate and glass plate. As a result, the dam structure can effectively seal and protect the filler and the organic materials of the OLED display substrate. It can not only effectively prevent external water, oxygen and pollutants from entering the interior of the dam structure, but also effectively prevent the filler from overflowing from the dam structure. At the same time, it greatly reduces the possibility of rework of the OLED display panel due to abnormal pressing or failure to press, thereby greatly improving the production quality and efficiency of the OLED display panel.

[0066] Furthermore, the -NH- group of the urethane ester group after UV pre-curing reacts with the protic acid (H) + The -NH2 group combines to form a weak bond. +It does not react at room temperature, thus preventing premature curing of the delayed UV curing encapsulant used in OLED display panels before lamination preparation and during lamination. This ensures that the viscosity of the delayed UV curing encapsulant for OLED display panels is 400 P·S to 1600 P·S during lamination, thereby greatly improving the stability of the delayed UV curing encapsulant used in OLED display panels. Furthermore, due to the -NH- group of the urethane group after UV pre-curing reacting with the protic acid (H... + The -NH2 group combines to form a weak bond. + When heated to the complete curing temperature, it can quickly decompose and release protic acid. The released protic acid can promote the rapid cross-linking and curing reaction of glycidyl ether epoxy resin and oxetane resin, so as to ensure the sealing and protection effect of the dam structure, thereby greatly improving the production quality of OLED display panels.

[0067] Furthermore, the uniformity of PS microspheres is relatively small, making it less prone to deviation during the lamination process. PS microspheres themselves can provide superior chemical stability, being resistant to acids, alkalis, and solvents, and not easily chemically degraded, thereby improving the stability and lifespan of OLED display panels. At the same time, PS microspheres can also reduce shrinkage and thermal stress, improving the stability of delayed UV curing encapsulants used in OLED display panels.

[0068] The delay principle of the organic delayed curing agent is as follows: after the photoinitiator absorbs light energy, it generates protic acid. The protic acid attacks the epoxy group to form oxonium ions. The oxonium ions cause the epoxy group to continuously open the ring, the molecular chain to continuously extend, and the molecules to cross-link to form a three-dimensional network structure, which eventually completes the curing. The organic delayed curing agent disclosed in this invention can absorb this protic acid, thereby reducing the formation of oxonium ions and slowing down the reaction rate. This provides a sufficient time window for dispensing, conveying, pressing preparation, and pressing fixation operations. Moreover, when the organic delayed curing agent is heated to above 30°C, it will release the protic acid again, so that the epoxy resin can be completely cured to achieve a good sealing effect.

[0069] In one embodiment, the viscosity of the delayed UV curing encapsulant for OLED display panels after UV pre-curing is 400 P·S to 1600 P·S and the duration is 20 min. This allows sufficient time for the conveying process, pressing preparation, and pressing fixation process, while not affecting the sealing and protection effect of the dam structure. It is especially suitable for high-precision OLED display panel production lines with long conveying distances and long pressing preparation times.

[0070] In one embodiment, the glycidyl ether epoxy resin is one of the following compounds:

[0071]

[0072] Furthermore, bisphenol A epoxy resin and bisphenol F epoxy resin possess excellent adhesion, electrical insulation, and sealing properties. They can not only effectively improve the sealing and protection effect of the dam structure, preventing external water, oxygen, or other pollutants from entering the dam structure and preventing filler from overflowing from the dam structure, but also ensure that the dam structure can be firmly bonded and fixed to the OLED display substrate. In addition, they can prevent short circuits between the OLED light-emitting chip and the carrier, thereby greatly improving the stability and production quality of the OLED display panel.

[0073] In a preferred embodiment, the glycidyl ether epoxy resin is a bisphenol A epoxy resin.

[0074] In one embodiment, R3 is compound B1-B. 10 At least one of the following:

[0075] .

[0076] In a preferred embodiment, R3 is compound B1 (3-ethyl-3-hydroxymethyloxetane).

[0077] In one embodiment, the photoinitiator is a thionium salt.

[0078] In one embodiment, the thioonium salt includes at least one selected from triarylthioonium salt, triphenylthioonium salt, diphenylmethylthioonium salt, bis(4-methoxyphenyl)thioonium salt, and tributylthioonium salt.

[0079] In one embodiment, the nanoscale filler includes at least one of nanoscale silica, nanoscale hydrotalcite, nanoscale talc, nanoscale montmorillonite, and nanoscale calcium carbonate.

[0080] In one embodiment, the defoamer is a silicone-based defoamer.

[0081] In one embodiment, the dispersant is the DISPERBYK-110 series.

[0082] In one embodiment, the PS microspheres are SBX series 10-micron PS microspheres.

[0083] In one embodiment, the method for synthesizing the organic delayed curing agent includes some or all of the following steps:

[0084] Sa1, R1 and R2 are placed into the reactor in a preset mass ratio, and a catalyst is added;

[0085] Sa2, adjust the temperature inside the reactor to 75℃~85℃ so that R1 and R2 react for 240min~300min to obtain R4;

[0086] In one embodiment, the temperature inside the reactor is adjusted to 75°C to 85°C. When the content of NCO groups (i.e. isocyanate groups) in the solution inside the reactor reaches the theoretical value, R4 can be obtained.

[0087] Sa3, after obtaining R4, R3 is continuously added to the reactor until the NCO groups of R4 are completely reacted to obtain the organic delayed curing agent R5.

[0088] In this embodiment, after obtaining R4, R3 is continuously added to the reactor until the NCO groups of R4 are completely reacted to obtain the organic delayed curing agent R5, thereby completing the preparation and synthesis of the organic delayed curing agent.

[0089] In one embodiment, after obtaining R4, R3 is continuously added to the reactor until the NCO group of R4 is completely reacted, and the temperature inside the reactor is always maintained at 75°C to 85°C.

[0090] In one embodiment, the catalyst is organotin dilaurate (DBTDL).

[0091] In one embodiment, the preset mass ratio of R1 to R2 is 1:2.

[0092] This disclosure also provides an OLED display panel, including an OLED display substrate and a glass plate. A dam structure is constructed on the OLED display substrate using the delayed UV curing encapsulant for OLED display panels described in any of the above embodiments to seal the gap between the OLED display substrate and the glass plate. The dam structure forms a dam sealing area, and the filler between the OLED display substrate and the glass plate fills the dam sealing area.

[0093] like Figure 1 As shown, this disclosure also provides a method for manufacturing an OLED display panel, used to manufacture the OLED display panel described in the above embodiments. The method for manufacturing the OLED display panel includes:

[0094] S10, Obtain the prepared OLED display substrate;

[0095] In one embodiment, the dispensing area of ​​the OLED display substrate is positioned facing upwards to facilitate the dispensing operation.

[0096] In one embodiment, delayed UV curable encapsulant for OLED display panels is dispensed onto the outer periphery of the dispensing area to form a dam structure; filler is dispensed onto the inner periphery of the dispensing area, i.e., inside the dam structure, so that the dam structure can restrict the flow range of the filler.

[0097] In one embodiment, the OLED display panel is a rigid glass OLED display panel.

[0098] S20, the first dispensing operation is performed on the dispensing area of ​​the OLED display substrate using delayed UV curing encapsulant for OLED display panels, so as to build a dam structure on the OLED display substrate.

[0099] It is understandable that the rotatable single bonds and lack of conjugated systems within the oxy-heterocyclic ring give it a certain degree of flexibility. Furthermore, the main chain of the organic delayed-curing agent contains methylene (-CH2-) and ether (-O-) flexible units, which effectively improves the overall flexibility of the delayed-UV curing encapsulant used in OLED display panels. At the same time, PS microspheres, as elastic particles, can effectively buffer and disperse the impact force received by the delayed-UV curing encapsulant used in OLED display panels, further improving the overall flexibility of the delayed-UV curing encapsulant used in OLED display panels. This significantly reduces the probability of cracking of the delayed-UV curing encapsulant used in OLED display panels during the lamination process, thereby greatly improving the production quality of OLED display panels.

[0100] It can also be understood that the delayed UV curing encapsulant used in OLED display panels is subjected to shear force, causing it to exhibit low viscosity and flowability due to its high thixotropy, thus precisely forming a dam structure. After the shear force on the delayed UV curing encapsulant disappears (i.e., after the dispensing operation is completed), nanoscale fillers rapidly construct a three-dimensional physical cross-linked network. Combined with the high initial viscosity of glycidyl ether epoxy resin, this allows the delayed UV curing encapsulant to instantly lock its dispensing shape. This not only effectively suppresses the instantaneous deformation rate of the delayed UV curing encapsulant but also inhibits the delayed UV curing of the OLED display panel. The delayed UV curing encapsulant avoids collapse and sagging due to gravity or surface tension. Simultaneously, oxetane resins and glycidyl ether epoxy resins synergistically form an interpenetrating network, combined with the physical support of PS microspheres. The glycidyl ether epoxy resin provides rigid support, while the oxetane resin and PS microspheres provide flexible buffering through their elastic deformation capabilities. This collectively constructs a "rigid matrix + flexible buffer" composite structure, effectively preventing deformation or collapse of the dam structure built with delayed UV curing encapsulant for OLED display panels within a certain period after dispensing. This effectively prevents filler adhesive from overflowing the dam structure, thus significantly improving the production quality of OLED display panels.

[0101] In one embodiment, the dam structure seals and protects the organic materials and filler on the OLED display substrate, which not only prevents external water, oxygen or other pollutants from entering the dam structure, but also prevents the filler from overflowing from the dam sealing area.

[0102] S30, a second dispensing operation is performed on the damming and sealing area of ​​the OLED display substrate using filler adhesive, so that the filler adhesive fills the damming and sealing area;

[0103] In this embodiment, a second dispensing operation is performed on the damming and sealing area of ​​the OLED display substrate using filler adhesive. This ensures that the filler adhesive fills the damming and sealing area and that a clearance gap of 0.5mm to 0.8mm is formed between the filler adhesive and the delayed UV curing encapsulant used in the OLED display panel. This not only allows the filler adhesive to fill the gap between the OLED display substrate and the glass plate evenly, but also avoids overflow of the filler adhesive, reducing the need for adhesive removal in subsequent stages, thereby improving the production quality and efficiency of the OLED display panel.

[0104] S40, UV pre-curing is performed on the OLED display substrate after the second dispensing operation; wherein the UV pre-curing temperature is 24.5℃~25.5℃, and the UV lamp power is 100mw / cm².2 ~110mw / cm 2 The energy is 1000 mJ / cm². 2 ~1500mj / cm 2 ;

[0105] It is understandable that during the UV pre-curing process, the photoinitiator produces protic acids, and the organic delayed curing agent contains urethane groups. The -NH- of the urethane group can react with the protic acid (H+). + The -NH2 group combines to form a weak bond. + By absorbing proton acids, the concentration of proton acids is effectively reduced, thereby slowing down the ring-opening reaction rate of aliphatic epoxy resins and effectively delaying the curing process of delayed UV-curing encapsulants used in OLED display panels; simultaneously, the positively charged -NH2... + The group causes electrostatic repulsion between the organic delayed-curing agent molecules, effectively preventing agglomeration and reducing the viscosity of the delayed-UV curing encapsulant used in OLED display panels after UV pre-curing. Furthermore, because the NH bond of the urethane group is adjacent to an ester group (-COO-) and an oxygen heterocycle, the steric hindrance formed by the ester group and the oxygen heterocycle inhibits intermolecular hydrogen bonding, reducing the density of hydrogen bonding and further lowering the viscosity of the delayed-UV curing encapsulant used in OLED display panels. Especially when combined with 0.1 to 1 part of organic delayed-curing agent, this improves the viscosity of the delayed-UV curing encapsulant on the OLED display substrate after UV pre-curing. The viscosity during the pressing and fixing process with the glass plate is 400 P·S to 1600 P·S. This ensures that the OLED display substrate and the glass plate can be pressed and fixed together, while also ensuring that the delayed UV curing encapsulant used in the OLED display panel can be effectively sealed and bonded to the OLED display substrate and the glass plate through its own viscosity. This allows the dam structure to effectively seal and protect the filler and the organic materials of the OLED display substrate. It can not only effectively prevent external water, oxygen and pollutants from entering the dam structure, but also effectively prevent the filler from overflowing from the dam structure, further improving the production quality of the OLED display panel.

[0106] It is also understandable that the -NH- group of the urethane group after UV pre-curing reacts with the protic acid (H) + The -NH2 group combines to form a weak bond. +It does not react at room temperature, thus preventing premature curing of the delayed UV curing encapsulant used in OLED display panels before lamination preparation and during lamination. This ensures that the viscosity of the delayed UV curing encapsulant for OLED display panels is 400 P·S to 1600 P·S during lamination, thereby greatly improving the stability of the delayed UV curing encapsulant used in OLED display panels. Furthermore, due to the -NH- group of the urethane group after UV pre-curing reacting with the protic acid (H... + The -NH2 group combines to form a weak bond. + When heated to the complete curing temperature, it can quickly decompose and release protic acid. The released protic acid can promote the rapid cross-linking and curing reaction of glycidyl ether epoxy resin and oxetane resin, so as to ensure the sealing and protection effect of the dam structure, thereby greatly improving the production quality of OLED display panels.

[0107] S50, after completing the UV pre-curing operation, the OLED display substrate and the glass plate are pressed together so that the glass plate is sealed and covered at the opening of the dam structure, and together with the dam sealing area, they form a dam sealing cavity to seal the gap between the OLED display substrate and the glass plate, thus obtaining a semi-finished OLED display panel.

[0108] In one embodiment, the OLED display substrate and the glass plate are pressed together by a pressing machine to ensure that the filler glue in the damming area is evenly filled. At the same time, the two sides of the damming structure can be sealed and bonded to the OLED display substrate and the glass plate respectively, thereby enabling the damming structure to effectively seal and protect the organic materials and filler glue of the OLED display substrate.

[0109] In one embodiment, the pressure of the pressing machine is 0.25MPa-0.35MPa to ensure that the two sides of the dam structure can be reliably sealed and bonded to the OLED display substrate and the glass plate, thereby effectively improving the sealing effect of the dam sealing cavity. This not only effectively prevents external water, oxygen and pollutants from entering the interior of the dam structure, but also effectively prevents filler from overflowing from the dam structure, further improving the production quality of the OLED display panel.

[0110] In one embodiment, the thickness of the delayed UV curing encapsulant and filler glue used for the OLED display panel after lamination is 10 μm ± 0.3 μm.

[0111] S60 performs a complete curing operation on the OLED display panel semi-finished product to fully cure the delayed UV curing encapsulant and filler used in the OLED display panel, thereby obtaining the OLED display panel.

[0112] In this embodiment, the OLED display panel semi-finished product undergoes a complete curing operation to ensure that the delayed UV curing encapsulant and filler used in the OLED display panel are fully cured, resulting in the OLED display panel. This allows the two sides of the dam structure to be more firmly bonded and sealed to the OLED display substrate and glass plate, thereby achieving sealing and protection of the organic materials and filler on the OLED display substrate. This not only prevents external water, oxygen, or other pollutants from entering the dam sealing cavity, but also prevents the filler from overflowing from the dam sealing cavity, thus greatly improving the production quality and efficiency of the OLED display panel.

[0113] In this embodiment, the manufacturing method of the OLED display panel includes the following steps: First, a prepared OLED display substrate is obtained; then, a first dispensing operation is performed on the dispensing area of ​​the OLED display substrate using a delayed UV-curable encapsulant for OLED display panels to construct a dam structure on the OLED display substrate; second, a second dispensing operation is performed on the dam sealing area of ​​the OLED display substrate using filler to fill the dam sealing area; then, a UV pre-curing operation is performed on the OLED display substrate after the second dispensing operation; wherein, the UV pre-curing temperature is 24.5℃-25.5℃, and the power of the UV lamp is 100mw / cm². 2 -110mw / cm 2 The energy is 1000 mJ / cm². 2- 1500mj / cm 2 Next, the OLED display substrate and the glass plate after UV pre-curing are pressed together so that the glass plate is sealed at the opening of the dam structure and together with the dam sealing area, they form a dam sealing cavity to seal the gap between the OLED display substrate and the glass plate, thus obtaining a semi-finished OLED display panel. Finally, the semi-finished OLED display panel is fully cured to completely cure the delayed UV curing encapsulant and filler used in the OLED display panel, thus obtaining the OLED display panel.

[0114] In one embodiment, step S60, which involves a complete curing operation on the OLED display panel semi-finished product, includes some or all of the following steps:

[0115] S61, heat the OLED display panel semi-finished product to 70℃-90℃ for 20min-30min.

[0116] In this embodiment, the OLED display panel semi-finished product is heated to 70°C-90°C for 20-30 minutes to ensure that the weakly bonded -NH2 groups can be satisfied using a relatively low temperature. + The release.

[0117] The following are some specific examples. When %, it refers to a percentage by weight. It should be noted that the following examples do not exhaustively list all possible scenarios, and unless otherwise specified, the materials used in the examples are commercially available.

[0118] Table 1 Formulation of Delayed UV Curing Encapsulant for OLED Display Panels

[0119]

[0120]

[0121] in,

[0122] Examples 1-11 use organic extended curing agent R5 and the following synthetic pathways for the synthesis reaction:

[0123] R3 is compound B1, 3-ethyl-3-hydroxymethyloxetane;

[0124] First, R1 and R2 are placed in a reactor at a mass ratio of 1:2, and a catalyst (organotin dilaurate (DBTDL)) is added. Then, the temperature inside the reactor is adjusted to 75℃~85℃ and heated for 240min~300min to obtain R4. After obtaining R4, R3 is continuously added to the reactor until the NCO groups of R4 are completely reacted to obtain the organic delayed curing agent R5.

[0125] Example 1: Prepare the required materials according to Table 1 to prepare a delayed UV curing encapsulant with a viscosity of 400±2 P·S for OLED display panels;

[0126] Example 2: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.1, and the amount of delayed curing agent R5 added is 0.1.

[0127] Example 3: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.2, and the amount of delayed curing agent R5 added is 0.2.

[0128] Example 4: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.3, and the amount of delayed curing agent R5 added is 0.3.

[0129] Example 5: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.4, and the amount of delayed curing agent R5 added is 0.4.

[0130] Example 6: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.5, and the amount of delayed curing agent R5 added is 0.5.

[0131] Example 7: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.6, and the amount of delayed curing agent R5 added is 0.6.

[0132] Example 8: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.7, and the amount of delayed curing agent R5 added is 0.7.

[0133] Example 9: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.8, and the amount of delayed curing agent R5 added is 0.8.

[0134] Example 10: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 0.9, and the amount of delayed curing agent R5 added is 0.9.

[0135] Example 11: The difference from Example 1 is that the content of bisphenol A epoxy resin is reduced by 1, and the amount of delayed curing agent R5 added is 1.

[0136] The curing rates of the delayed UV curing encapsulants for OLED display panels prepared in Examples 1-11 were analyzed for different organic delayed curing agent contents. Figure 2 This data was obtained using an infrared spectrometer. The sample was subjected to UV irradiation at 25±0.5℃ with a UV power of 110mw / cm². 2 UV energy is 1000 mJ / cm 2 It is then baked at 80℃ for 30 minutes to prepare.

[0137] The viscosity changes of the delayed UV-curable encapsulants prepared in Examples 1-11 for OLED display panels after UV pre-curing were analyzed for different contents of organic delayed curing agents. Figure 3 As shown, the data was obtained by a rheometer. The detection conditions were: constant temperature of 25℃, constant temperature time of 60s, and then maintained at 25±0.5℃, illumination time of 15s, and 20min after illumination, which is 1275s in the table.

[0138] Through observation Figure 2 and Figure 5 The data leads to the following conclusions:

[0139] (1) When other conditions remain unchanged, as the content of organic delayed curing agent R5 increases, the curing rate of delayed UV curing encapsulant for OLED display panels gradually decreases. When the content of organic delayed curing agent R5 is ≤0.6%, the curing rate is greater than 95%, while when the content of organic delayed curing agent R5 is ≥0.6%, the curing rate is 95%.

[0140] (2) When other conditions remain unchanged, as the content of organic delayed curing agent R5 increases, the delayed curing viscosity of the delayed UV curing encapsulant used in OLED display panels gradually decreases. When the content of organic delayed curing agent R5 is ≥0.5%, the delayed curing viscosity of the delayed UV curing encapsulant used in OLED display panels is 400 P·S to 1600 P·S. When the content of organic delayed curing agent R5 is ≤0.4% or less, the delayed curing viscosity of the delayed UV curing encapsulant used in OLED display panels is 400 P·S to 1600 P·S.

[0141] (3) When other conditions remain unchanged, when the content of organic delayed curing agent R5 is in the range of 0% to 1%, the water vapor transmission rate of all delayed UV curing encapsulants used for OLED display panels meets the process requirements, indicating that the content of organic delayed curing agent R5 has little effect on the water and oxygen isolation performance of delayed UV curing encapsulants used for OLED display panels.

[0142] This indicates that adding the organic delayed curing agent R5 can effectively slow down the curing process of the delayed UV curing encapsulant used in OLED display panels, which is more in line with the process requirements of OLED display panels. It can also effectively isolate water and oxygen, providing good protection for organic materials, and effectively prevent filler from overflowing from the dam structure.

[0143] The delayed UV curing encapsulant prepared in Examples 1-11 for OLED display panels is applied to the OLED display panel, which is called the manufacturing method of OLED display panels, and includes the following steps:

[0144] (1) Obtain the prepared OLED display substrate and place the OLED display substrate with the dispensing area facing upwards;

[0145] (2) Dispensing operation.

[0146] First, a delay-curing UV encapsulating adhesive for OLED display panels is applied to the dispensing area of ​​the OLED display substrate using a dispensing machine to create a dam structure on the OLED display substrate. Then, a filler adhesive is applied to the dam sealing area of ​​the OLED display substrate using a dispensing machine to fill the dam sealing area.

[0147] (3) UV pre-curing operation.

[0148] In this embodiment, a UV lamp is used to irradiate the substrate after dispensing. Under the action of UV irradiation, the photoinitiator of the DAM adhesive releases proton acid and reacts with the epoxy resin, increasing the viscosity of the adhesive. The delayed curing agent R5 absorbs some of the proton acid, so the delayed UV curing encapsulant used in OLED display panels cannot be completely cured. Within 20 minutes, the viscosity of the delayed UV curing encapsulant used in OLED display panels is 400 P·S to 1600 P·S.

[0149] (4) Pressing and fixing operation

[0150] The OLED display substrate, after completing the second dispensing operation, undergoes a UV pre-curing process; the UV pre-curing temperature is 24.5℃-25.5℃, and the UV lamp power is 100mw / cm². 2 -110mw / cm 2 The energy is 1000 mJ / cm². 2- 1500mj / cm 2 .

[0151] (5) Complete curing operation

[0152] The OLED display panel semi-finished product undergoes a complete curing process to fully cure the delayed UV curing encapsulant and filler used in the OLED display panel, thereby obtaining the OLED display panel. The specific steps of the complete curing process are as follows: the OLED display panel semi-finished product is heated to 70℃-90℃ for 20-30 minutes to ensure that the weakly bonded -NH2 groups can be satisfied using a relatively low temperature. + The release.

[0153] Comparative Example 1

[0154] The difference from Example 6 is that the temperature in (3) of the UV pre-curing operation is 25°C and the power of the UV lamp is 110mw / cm. 2 Energy is 1000 mJ / cm 2 Replace "temperature is 30℃, UV lamp power is 120mw / cm" with "temperature is 30℃, UV lamp power is 120mw / cm". 2 Energy is 1550 mJ / cm 2 "The rest remain unchanged."

[0155] Comparative Example 2

[0156] The difference from Example 6 is that the temperature in (3) of the UV pre-curing operation is 25°C and the power of the UV lamp is 110mw / cm. 2 The energy is 1000 mJ / cm². 2 Replace "temperature is 24℃, UV lamp power is 80mw / cm" with "temperature is 24℃, UV lamp power is 80mw / cm". 2The energy is 900 mJ / cm 2 "The rest remain unchanged."

[0157] Comparative Example 3

[0158] The difference from Example 6 is that (5) heating and curing “baking the OLED display panel semi-finished product at 80°C for 30 minutes” is replaced with “baking the OLED display panel semi-finished product at 60°C for 40 minutes”.

[0159] Comparative Example 4

[0160] The difference from Example 6 is that (5) heating and curing “baking the OLED display panel semi-finished product at 80°C for 30 min” is replaced with “baking the OLED display panel semi-finished product at 95°C for 10 min”.

[0161] According to the performance test in Table 2, the delayed UV curing encapsulant for OLED display panels in Examples 1-11 above was tested in the non-UV pre-curing stage, the UV pre-curing stage, and after heat curing, to obtain the experimental data in Table 3.

[0162] Table 2 Performance Test Table

[0163]

[0164]

[0165] Table 3

[0166]

[0167]

[0168] As can be seen from Examples 1 and 2-11 in Table 3, the addition of 0.1-1.0 parts of organic delayed curing agent R5 in Examples 2-11 effectively reduces the viscosity of the delayed UV curing encapsulant for OLED display panels within 20 minutes after UV pre-curing at 25°C. This ensures that the viscosity of the delayed UV curing encapsulant for OLED display panels remains between 400 P·S and 1600 P·S within 20 minutes, which is beneficial for the pressing and fixing operation between the OLED display substrate and the glass plate. It ensures that both sides of the delayed UV curing encapsulant for OLED display panels can reliably seal and bond to the OLED display substrate and the glass plate through their own viscosity, so that the dam structure can effectively seal and protect the filler and the organic materials of the OLED display substrate. Furthermore, the added 0.1-1.0 parts of organic delayed curing agent R5 also plays a good role in delayed curing, which can reserve sufficient time window for pressing preparation and pressing operation, and will not affect the sealing effect between the glass plate and the substrate.

[0169] Furthermore, please refer to the following: Figures 2 to 4 When the amount of organic delayed curing agent used in Examples 6-7 is 0.5-0.6 parts, the overall performance of Examples 6-7 is significantly better than that of Examples 2-5 and 8-11, with Example 6 having the best overall performance.

[0170] As can be seen from Examples 1 and 2-11 in Table 3, the addition of 0.1 to 1.0 parts of organic delayed curing agent can effectively improve the Shore hardness of the delayed UV curing encapsulant used in OLED display panels, so as to ensure that it has good toughness and can better buffer the stress during the pressing operation, thereby reducing the probability of cracking of the dam structure.

[0171] After heat curing, the delayed UV-curing encapsulating adhesives (i.e., dam structures) for OLED display panels of Example 6 and Comparative Examples 1-4 were visually inspected. When the UV pre-curing parameters of Comparative Examples 1-2 were not between 24.5℃ and 25.5℃, and the UV lamp power was 100 mw / cm², the results showed that... 2 ~110mw / cm 2 The energy is 1000 mJ / cm². 2 ~1500mj / cm 2 Furthermore, when the heating curing conditions of Comparative Examples 3-4 were not at a temperature of 70℃~90℃ and a time of 20min~30min, it was impossible to prepare a delayed UV curing encapsulant for OLED display panels with a viscosity maintained at 400P·S~1600P·S within 20min after UV pre-curing, resulting in the overall performance of Comparative Examples 3-4 being significantly worse than that of Example 6.

[0172] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A delayed UV-curable encapsulant for OLED display panels, used to construct dam structures on OLED display substrates, characterized in that, Including the following mass fractions: The organic delayed curing agent is synthesized via the following synthetic pathway: R1 is isoflurone diisocyanate; R2 is polycarbonate diol; R3 is an oxobutane resin; R4 is an intermediate compound; The organic delayed curing agent is used to absorb the photoinitiator to generate proton acid during the UV pre-curing operation, thereby delaying the curing of the delayed UV curing encapsulant for OLED display panels; The organic delayed curing agent is used to reduce the viscosity of the delayed UV curing encapsulant for the OLED display panel after UV pre-curing, so that the viscosity of the delayed UV curing encapsulant for the OLED display panel after UV pre-curing is 400 P·S to 1600 P·S during the pressing and fixing operation of the OLED display substrate and the glass plate.

2. The delayed UV curing encapsulant for OLED display panels according to claim 1, characterized in that, The viscosity of the delayed UV-curing encapsulant for OLED display panels after the UV pre-curing operation is 400 P·S to 1600 P·S, and the duration is 20 min.

3. The delayed UV curing encapsulant for OLED display panels according to claim 1, characterized in that, In one embodiment, the glycidyl ether epoxy resin is one of the following compounds:

4. The delayed UV curing encapsulating adhesive for OLED display panels according to claim 1, characterized in that, R3 is the following compound B1-B 10 At least one of the following:

5. The delayed UV curing encapsulant for OLED display panels according to claim 1, characterized in that, The photoinitiator is a thionium salt.

6. The delayed UV curing encapsulant for OLED display panels according to claim 1, characterized in that, The thioonium salt includes at least one selected from triarylthioonium salt, triphenylthioonium salt, diphenylmethylthioonium salt, bis(4-methoxyphenyl)thioonium salt, and tributylthioonium salt; and / or, The nanoscale filler includes at least one of nanoscale silica, nanoscale hydrotalcite, nanoscale talc, nanoscale montmorillonite, and nanoscale calcium carbonate; and / or The defoamer is an organosilicon defoamer; and / or... The dispersant is a DISPERBYK-110 series; and / or, The PS microspheres are SBX series 10-micron PS microspheres.

7. The delayed UV curing encapsulant for OLED display panels according to claim 1, characterized in that, The method for synthesizing the organic delayed curing agent includes: R1 and R2 are placed into the reactor at a preset mass ratio, and a catalyst is added; The temperature inside the reactor is adjusted to 75℃~85℃ so that R1 and R2 react for 240min~300min to obtain R4; After obtaining R4, R3 is continuously added to the reactor until the NCO groups of R4 are completely reacted to obtain the organic delayed curing agent R5.

8. The delayed UV curing encapsulant for OLED display panels according to claim 7, characterized in that, The catalyst is organotin (DBTDL).

9. An OLED display panel, comprising an OLED display substrate and a glass plate, characterized in that, The dam structure is constructed on the OLED display substrate using the delayed UV curing encapsulant for OLED display panels as described in any one of claims 1 to 8, to seal the gap between the OLED display substrate and the glass plate. The dam structure forms a dam sealing area, and filler adhesive between the OLED display substrate and the glass plate is applied to fill the dam sealing area.

10. A method for manufacturing an OLED display panel, characterized in that, The method for manufacturing the OLED display panel as described in claim 9 includes: Obtain the prepared OLED display substrate; The delayed UV curing encapsulant for OLED display panels is used to perform the first dispensing operation on the dispensing area of ​​the OLED display substrate in order to construct the dam structure on the OLED display substrate. The filler adhesive is used to perform a second dispensing operation on the damming and sealing area of ​​the OLED display substrate, so that the filler adhesive fills the damming and sealing area; The OLED display substrate, after completing the second dispensing operation, undergoes a UV pre-curing process; wherein the UV pre-curing temperature is 24.5℃-25.5℃, and the UV lamp power is 100mw / cm². 2 -110mw / cm 2 The energy is 1000 mJ / cm². 2- 1500mj / cm 2 ; After completing the UV pre-curing operation, the OLED display substrate and the glass plate are pressed together so that the glass plate is sealed and covered at the opening of the dam structure, and together with the dam sealing area, they form a dam sealing cavity to seal the gap between the OLED display substrate and the glass plate, thereby obtaining the OLED display panel semi-finished product. The OLED display panel semi-finished product is subjected to a complete curing operation to fully cure the delayed UV curing encapsulant and the filler for the OLED display panel, thereby obtaining the OLED display panel.

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