CN117866559A - Folding OCA adhesive and film with high adhesive properties for UTG materials and preparation method thereof - Google Patents

Abstract

The present invention discloses a folding OCA adhesive, an adhesive film and a preparation method thereof having high viscosity to UTG materials, wherein the adhesive comprises the following raw material components by weight: 80-90 parts of OCA glue, 0.02-0.04 parts of a thermosetting agent, and 10-20 parts of a first solvent; the raw material components of the OCA glue include: 15-20 parts of isooctyl acrylate, 9-12 parts of butyl acrylate, 2.5-3.5 parts of 4-hydroxybutyl acrylate, 3‰ parts of methyl methacrylate, 3‰ parts of isooctadecyl acrylate, 0.6‰-0.8‰ parts of an initiator, and 65-75 parts of a second solvent. The OCA adhesive provided by the present invention is obtained by adding a monomer ISTA having good compatibility with the system and adjusting the glass transition temperature of an acrylic copolymer, thereby obtaining a high-viscosity OCA, and the obtained OCA has extremely high viscosity to the UTG material, while improving the creep recovery and stress relaxation of the adhesive.

Description

Folding OCA adhesive and film with high adhesion to UTG materials and preparation method thereof

Technical Field

The present invention relates to the field of adhesive materials, and in particular to a folded OCA adhesive having high adhesive properties for UTG materials, an adhesive film and a preparation method thereof.

Background technique

In recent years, foldable devices have become increasingly popular due to their excellent portability, and are increasingly widely used in the fields of foldable mobile phones, smart wearables, vehicles, electronic equipment, etc. Ultra-thin glass (UTG) refers to glass with a thickness of less than 0.1mm. Due to its ultra-thin characteristics, it has excellent bendability and high hardness scratch resistance, making it an important material in the field of foldable flexible cover panels after CPI film materials. Foldable OCA (Optically Clear Adhesive) bonds UTG to a foldable protective film. Generally, the OCA adhesive used in foldable devices needs to have durability against environmental changes, as well as strong bonding properties, excellent high and low temperature modulus stability, and good creep recovery, so as to reduce irreversible deformation and avoid cohesive failure, thereby increasing the service life of foldable devices.

In some cases, the adhesive layer of the bendable device will become hard as the temperature decreases. For example, when the bendable device is folded in a low temperature environment, it is easy to whiten or break at the folding layer. In addition, if the OCA adhesive used cannot maintain good viscosity under a specific environment, it will also cause the risk of bubbles or even falling off between the film and the UTG. More importantly, if the foldable device is used at a lower or higher temperature, the OCA adhesive must have good creep recovery. For this, CN108753185A has developed an OCA optical tape for TP and a preparation method thereof, which includes 50-70 parts of acrylate polymer, 20-50 parts of acrylate monomer, 0.05-0.5 parts of cross-linking agent, 0.5-0.8 parts of photoinitiator and 0.2-0.4 parts of auxiliary agent by weight. The OCA optical adhesive has poor creep recovery and stress relaxation, resulting in creases after the number of folds increases.

So far, the OCA adhesive products used for UTG on the market have low creep recovery at different temperatures and low viscosity. During the bending process, the OCA adhesive material peels off from the UTG, and the comprehensive performance is far from meeting the needs of consumers. Therefore, developing an OCA adhesive that has good adhesion to UTG materials and good creep recovery and stress relaxation properties is the current research focus in this field.

Summary of the invention

The technical problem to be solved by the present invention is to provide a folded OCA adhesive, an adhesive film and a preparation method thereof having high adhesion properties to UTG materials in view of the deficiencies in the above-mentioned prior art.

In order to solve the above technical problems, the technical solution adopted by the present invention is: in the first aspect of the present invention, a folding OCA adhesive having high adhesive properties for UTG materials is provided, comprising the following raw material components by weight: 80-90 parts of OCA glue, 0.02-0.04 parts of thermal curing agent, and 10-20 parts of a first solvent;

Among them, the OCA glue is prepared by polymerization reaction of the following raw material components in parts by weight: 15-20 parts of isooctyl acrylate (2-EHA), 9-12 parts of butyl acrylate (BA), 2.5-3.5 parts of 4-hydroxybutyl acrylate (4-HBA), 3‰ parts of methyl methacrylate (MMA), 3‰ parts of isostearyl acrylate (ISTA), 0.6‰-0.8‰ parts of initiator (AIBN), and 65-75 parts of the second solvent.

Preferably, the OCA glue is prepared by the following method:

According to the weight ratio, isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate, isostearyl acrylate (ISTA) and part of the second solvent are mixed, nitrogen is introduced, and the mixture is heated and stirred. Then, part of the initiator is added, and the mixture is heated and stirred for reaction; the temperature is then increased to react; the remaining part of the initiator is added, and the temperature is continued to be increased for reaction; after the reaction is completed, the mixture is cooled, and the remaining part of the second solvent is added for dilution to obtain OCA glue.

Preferably, the OCA glue is prepared by the following method:

According to the weight ratio, isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate, isooctadecyl acrylate (ISTA) and part of the second solvent are mixed, nitrogen is introduced, and part of the initiator is added after stirring at 60-62° C. for at least 30 minutes, the temperature is maintained, and the reaction is stirred for 1-4 hours; then the temperature is raised to 63-68° C. for reaction for 3-4 hours; the remaining part of the initiator is added, the temperature is raised to 70-72° C. for continuous reaction for 3-6 hours; after cooling to room temperature, the remaining part of the second solvent is added for dilution to obtain OCA glue.

Preferably, the OCA glue is prepared by the following method:

According to the weight ratio, isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate, isostearyl acrylate (ISTA) and part of the second solvent are mixed, nitrogen is introduced, and part of the initiator is added after stirring at 60-62° C. for at least 30 minutes, and the temperature is maintained and stirred for 2 hours; then the temperature is raised to 65° C. and reacted for 3 hours; the remaining part of the initiator is added, the temperature is raised to 70-72° C. and the reaction is continued for 5 hours; after cooling to room temperature, the remaining part of the second solvent is added for dilution to obtain OCA glue with a solid content of 25-30%.

Preferably, the first solvent and the second solvent are both ethyl acetate.

Preferably, the initiator is AIBN.

Preferably, the thermal curing agent is hexamethylene diisocyanate.

A second aspect of the present invention provides a folded OCA adhesive film having high adhesion to UTG materials, which is prepared using the OCA adhesive as described above.

A third aspect of the present invention provides a method for preparing a folded OCA adhesive film having high adhesion to UTG material as described above, comprising the following steps:

S1, mixing OCA glue, a thermal curing agent and a first solvent, and stirring evenly to obtain a folding OCA adhesive having high adhesion to UTG material;

S2. Apply the folded OCA adhesive on the first release film, control the dry adhesive thickness to 30-80 μm, put it into an oven, dry it at 110-130° C. for 1-4 min, adhere the second release film to the adhesive surface of the formed dry adhesive layer, and ripen it at 50-70° C. for 24-48 h to obtain the folded OCA adhesive film with high adhesion to the UTG material.

Preferably, the method for preparing the folded OCA adhesive film having high adhesion to the UTG material comprises the following steps:

S1. Under the conditions of 23-25° C. and 50±3% humidity, mix the OCA glue, the thermal curing agent and the first solvent, and stir evenly to obtain a folding OCA adhesive having high adhesion to the UTG material;

S2. Apply the folded OCA adhesive on the first release film, control the dry adhesive thickness to 50 μm, put it into an oven, raise the temperature from 25°C to 120°C, and then dry it at 120°C for 2 minutes, adhere the second release film to the adhesive surface of the formed dry adhesive layer, and ripen it at 60°C for 36 hours to obtain the folded OCA adhesive film with high adhesion to the UTG material.

The beneficial effects of the present invention are:

The present invention provides a folded OCA adhesive and an adhesive film having high viscosity to UTG materials and a preparation method thereof. The OCA adhesive provided by the present invention is obtained by adding a monomer ISTA having good compatibility with the system and adjusting the glass transition temperature of an acrylic copolymer, and the obtained OCA has extremely high viscosity to the UTG material, and at the same time improves the creep recovery and stress relaxation of the adhesive, and can avoid the defects of poor cohesion of the glue and poor uniformity of the system caused by achieving the above effect by increasing the crosslinking degree of the reaction;

The copolymer of the ISTA monomer added in the present invention and the acrylate reaction has strong bonding ability, and its reaction activity is high, and it can quickly undergo polymerization reaction and provide good viscosity, which plays a key role in the low modulus after the later film formation; ISTA has good wetting properties, and the physical entanglement of this long-chain monomer itself can also improve the cohesive strength. At the same time, 4-HBA has high cohesive strength. The combination of ISTA and 4-HBA can greatly improve the cohesive strength of the film and enhance the bonding performance between the film and UTG.

Detailed ways

The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

The test methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified. In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

The present invention provides a folding OCA adhesive having high adhesive properties for UTG materials, comprising the following raw material components by weight: 80 to 90 parts of OCA glue, 0.02 to 0.04 parts of a thermal curing agent, and 10 to 20 parts of a first solvent;

Among them, OCA glue is prepared by polymerization reaction of the following raw material components in parts by weight: 15-20 parts of isooctyl acrylate (2-EHA), 9-12 parts of butyl acrylate (BA), 2.5-3.5 parts of 4-hydroxybutyl acrylate (4-HBA), 3‰ parts of methyl methacrylate (MMA) (3 thousandths, i.e. 0.003 parts, and the rest are similar), 3‰ parts of isostearyl acrylate (ISTA), 0.6‰-0.8‰ parts of initiator (AIBN), and 65-75 parts of the second solvent.

In a preferred embodiment, OCA glue is prepared by the following method:

According to the weight ratio, isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate, isostearyl acrylate (ISTA) and part of the second solvent are mixed, placed in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, nitrogen is introduced, and part of the initiator is added after stirring at 60-62° C. for at least 30 minutes, the temperature is maintained, and the reaction is stirred for 2 hours; then the temperature is raised to 65° C. for 3 hours; the remaining part of the initiator is added, the temperature is raised to 70-72° C. and the reaction is continued for 5 hours; after cooling to room temperature, the remaining part of the second solvent is added for dilution to obtain OCA glue with a solid content of 25-30%.

In the OCA glue prepared by the present invention, isooctadecyl acrylate (ISTA) is added, which not only meets the low-temperature and low-modulus characteristics of the glue, but also improves the viscosity of the glue. The copolymer of ISTA and acrylate has a strong bonding ability. UTG has a smooth surface and high flatness, which requires the film to have extremely high adhesion to the UTG material; ISTA has good wetting properties, and the physical entanglement of this long-chain monomer itself can also improve the cohesive strength. At the same time, 4-HBA has high cohesive strength. The combination of ISTA and 4-HBA can greatly improve the cohesive strength of the film and enhance the bonding performance between the film and UTG.

In a preferred embodiment, the first solvent and the second solvent are both ethyl acetate.

In a preferred embodiment, the initiator is AIBN (azobisisobutyronitrile).

In a preferred embodiment, the thermal curing agent is hexamethylene diisocyanate, which can undergo a rapid cross-linking and curing reaction with the OCA glue, thereby increasing its cross-linking degree and enhancing its cohesive force.

In a preferred embodiment, after the adhesive of the present invention is cross-linked and cured to form a film, the Tg value is between -30 and -45°C, and the storage modulus at -20°C is between 0.1 and 0.2 MPa.

In a preferred embodiment, the adhesive of the present invention has good creep performance. Under the condition of applying 20 KPa, the creep recovery rate at -20°C under the stress condition of 20 KPa exceeds 90%, and the maximum strain is greater than 100%.

In a preferred embodiment, after the adhesive of the present invention is cross-linked and cured to form a film, the peel strength test result of the UTG material at room temperature for 24 hours is not less than 20N/25mm, and the peel strength test result of the UTG at 85°C is not less than 800N/25mm.

In a preferred embodiment, after the adhesive of the present invention is cross-linked and cured to form a film, the gel fraction is above 70%.

The present invention also provides a folded OCA adhesive film having high adhesion to UTG material, which is prepared by using the above OCA adhesive, and the specific steps include:

S1. Under the conditions of 23-25° C. and 50±3% humidity, mix the OCA glue, the thermal curing agent and the first solvent, and stir evenly to obtain a folding OCA adhesive having high adhesion to the UTG material;

S2. Apply the folded OCA adhesive on the first release film, control the dry adhesive thickness to 50 μm, put it into an oven, raise the temperature from 25°C to 120°C, and then dry it at 120°C for 2 minutes, adhere the second release film to the adhesive surface of the formed dry adhesive layer, and ripen it at 60°C for 36 hours to obtain a folded OCA adhesive film with high adhesion to UTG material.

The above is the overall concept of the present invention, and detailed embodiments and comparative examples are provided below on the basis of the overall concept of the present invention to further illustrate the present invention.

Example 1

A folded OCA adhesive film having high adhesive properties to UTG material is prepared by the following method:

S1. Preparation of OCA glue:

According to weight, 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, 3‰ parts of methyl methacrylate, 3‰ parts of ISTA (isostearyl acrylate), and 48 parts of ethyl acetate were accurately weighed, placed in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, nitrogen was introduced, and 0.25‰ parts of AIBN were added after stirring at 62°C for 45 minutes, and the temperature was maintained and stirred for 2 hours; then the temperature was raised to 65°C for reaction for 3 hours; 0.6‰ parts of AIBN were added, the temperature was raised to 72°C and the reaction was continued for 5 hours; after cooling, 22 parts of ethyl acetate were added for dilution to obtain OCA glue with a solid content of 30%.

S2. Preparation of OCA film:

Under the conditions of 23-25°C and humidity of 50±3%, OCA glue, 0.03% isocyanate curing agent accounting for the mass fraction of OCA glue, and ethyl acetate accounting for the mass fraction of OCA glue are mixed and stirred evenly to obtain a folding OCA adhesive with a suitable coating viscosity and high adhesion to UTG materials;

S2. Apply the folded OCA adhesive on the first release film (PET release film), control the dry adhesive thickness to 50 μm, put it into an oven, raise the temperature from 25°C to 120°C, and then dry it at 120°C for 2 minutes, adhere the second release film (PET release film) to the adhesive surface of the formed dry adhesive layer, and ripen it at 60°C for 36 hours to obtain a folded OCA adhesive film with high adhesion to UTG material.

Example 2

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

Accurately weigh 15 parts of isooctyl acrylate, 15 parts of butyl acrylate, 3‰ parts of methyl methacrylate, 3‰ parts of ISTA (isostearyl acrylate), and 48 parts of ethyl acetate by weight, place them in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, introduce nitrogen, stir at 62°C for 45 minutes, then add 0.25‰ parts of AIBN, maintain the temperature and stir to react for 2 hours; then raise the temperature to 65°C and react for 3 hours; add 0.6‰ parts of AIBN, raise the temperature to 72°C and continue to react for 5 hours; after cooling, add 22 parts of ethyl acetate to dilute to obtain OCA glue with a solid content of 30%.

Example 3

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

According to weight, 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, 4‰ parts of methyl methacrylate, 2‰ parts of ISTA (isostearyl acrylate), and 48 parts of ethyl acetate were accurately weighed, placed in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, nitrogen was introduced, and 0.4‰ parts of AIBN were added after stirring at 62°C for 45 minutes, and the temperature was maintained and stirred for 2 hours; then the temperature was raised to 65°C for reaction for 3 hours; 0.6‰ parts of AIBN were added, the temperature was raised to 72°C and the reaction was continued for 5 hours; after cooling, 22 parts of ethyl acetate was added for dilution to obtain OCA glue with a solid content of 30%.

Example 4

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

According to weight, accurately weigh 27 parts of isooctyl acrylate, 3 parts of hydroxybutyl acrylate, 3‰ parts of methyl methacrylate, 3‰ parts of ISTA (isostearyl acrylate), and 50 parts of ethyl acetate, place them in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, pass nitrogen, stir at 62°C for 45 minutes, then add 0.25‰ parts of AIBN, maintain the temperature and stir to react for 2 hours; then raise the temperature to 65°C and react for 3h; add 0.6‰ parts of AIBN, raise the temperature to 72°C and continue to react for 5 hours; after cooling, add 20 parts of ethyl acetate to dilute to obtain OCA glue with a solid content of 30%.

Example 5

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

According to weight, 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, 3‰ parts of methyl methacrylate, 2‰ parts of ISTA (isooctadecyl acrylate), 1‰ part of LA (dodecyl acrylate), and 43 parts of ethyl acetate were accurately weighed, placed in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, nitrogen was introduced, and 0.25‰ parts of AIBN were added after stirring at 62°C for 45 minutes, and the temperature was maintained and stirred for 2 hours; then the temperature was raised to 65°C for reaction for 3 hours; 0.6‰ parts of AIBN were added, the temperature was raised to 72°C and the reaction was continued for 5 hours; after cooling, 27 parts of ethyl acetate was added for dilution to obtain OCA glue with a solid content of 30%.

Example 6

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

According to weight, accurately weigh 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, 3‰ parts of methyl methacrylate, 2‰ parts of ISTA (isostearyl acrylate), 1‰ part of LMA (lauryl methacrylate), and 56 parts of ethyl acetate, put them in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, pass nitrogen, stir at 62°C for 45 minutes, then add 0.5‰ parts of AIBN, maintain the temperature and stir to react for 2 hours; then raise the temperature to 65°C and react for 3h; add 0.7‰ parts of AIBN, raise the temperature to 72°C and continue to react for 5 hours; after cooling, add 14 parts of ethyl acetate to dilute to obtain OCA glue with a solid content of 30%.

Comparative Example 1

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

Accurately weigh 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, and 48 parts of ethyl acetate by weight, place in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, introduce nitrogen, stir at 62°C for 45 minutes, then add 0.25‰ parts of AIBN, maintain the temperature and stir to react for 2 hours; then raise the temperature to 65°C to react for 3 hours; raise the temperature to 72°C and continue to react for 5 hours; after cooling, add 22 parts of ethyl acetate to dilute to obtain OCA glue with a solid content of 30%.

Comparative Example 2

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

Accurately weigh 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, and 48 parts of ethyl acetate by weight, place them in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, introduce nitrogen, stir at 62°C for 45 minutes, then add 0.25‰ parts of AIBN, maintain the temperature and stir for 2 hours; then raise the temperature to 65°C and react for 3 hours; add 0.6‰ parts of AIBN, raise the temperature to 72°C and continue to react for 5 hours; after cooling, add 22 parts of ethyl acetate to dilute to obtain OCA glue with a solid content of 30%.

Comparative Example 3

The difference between this example and Example 1 is only the preparation method of OCA glue. In this example, OCA glue is prepared by the following method:

Accurately weigh 15 parts of isooctyl acrylate, 12 parts of butyl acrylate, 3 parts of hydroxybutyl acrylate, 3‰ parts of methyl methacrylate, 3‰ parts of C-17A (heptadecadecyl acrylate), and 48 parts of ethyl acetate by weight, place them in a four-necked flask equipped with a stirrer, a condenser and a nitrogen tube, introduce nitrogen, stir at 62°C for 45 minutes, then add 0.25‰ parts of AIBN, maintain the temperature and stir to react for 2 hours; then raise the temperature to 65°C and react for 3 hours; add 0.6‰ parts of AIBN, raise the temperature to 72°C and continue to react for 5 hours; after cooling, add 22 parts of ethyl acetate to dilute to obtain OCA glue with a solid content of 30%.

The formula of the OCA glue of Examples 1-6 and Comparative Examples 1-3 is specifically shown in Table 1 below:

Table 1

The film products prepared in Examples 1-6 and Comparative Examples 1-3 were subjected to the following performance tests:

(1) Peel strength test: The peel strength test is carried out according to the 180° peel strength test method for pressure-sensitive adhesive tapes and in accordance with GB/T2792-1998.

(2) Gel fraction test: A 1 gram film was placed on a nickel mesh and immersed in a mixed solvent of toluene and ethyl acetate (1:1). After standing for 72 hours, the sample was taken out and dried at 150°C for 2 hours and then weighed. The ratio of the residual weight of the film to the original weight was the gel fraction.

(3) Cohesion test: The sample is made into a 25mm*150mm size (the back of the double-sided tape needs to be pasted with 25um PET as the backing), and the test board is SUS304 mirror plate. After lamination, a 2kg roller is used to roll back and forth 3 times. After 20 minutes, a 1kg weight is hung. The displacement after room temperature/24h is ≤1.0mm, and the displacement after 70℃/24h is ≤2.0mm, which is qualified (PASS).

(4) Creep recovery test: The TA rheometer applies a shear stress of 20 kPa, with a recovery time of 600 s. The creep recovery rate at room temperature exceeds 90%, and the maximum strain exceeds 300%. The creep recovery rate at -20 °C exceeds 85%, and the maximum strain exceeds 90%, which is considered qualified (PASS).

(5) Static bending test: a 50 μm thick film is laminated with 50 μm PET on both sides, and then cut into 160 mm long * 40 mm wide strips. A 1N weight (100 g) is fixed to the tail of the sample through high-temperature insulating tape and hung on a fixture with a radius of R = 1.5 mm. The sample is placed in a 65°C/95% RH storage test box for 24 hours. After cooling, the sample is taken out and the width of the crease at the tail is measured. According to the current industry situation, a measured width of 35 mm indicates good bending resistance and is considered qualified (PASS).

The test results are shown in Table 2 below:

Table 2

It can be seen from the experimental data that the film products prepared in Examples 1-6 have excellent performance in various tests.

Comparative Example 1 did not add the initiator in the high temperature section, could not meet the low modulus and high viscosity performance, and the creep performance test did not meet the standard;

Comparative Example 2 lacks the long carbon chain monomer ISTA, and cannot simultaneously meet the requirements of low modulus and high viscosity, and the creep performance test also fails to meet the standards;

Comparative Example 3 adds long-chain monomer C-17A instead of ISTA, but the effect is not good and the viscosity is poor.

Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims (10)

1. The folding OCA adhesive with high viscosity property for UTG materials is characterized by comprising the following raw material components in parts by weight: 80-90 parts of OCA glue, 0.02-0.04 part of thermosetting agent and 10-20 parts of first solvent;

the OCA glue is prepared from the following raw material components in parts by weight through polymerization reaction: 15-20 parts of isooctyl acrylate, 9-12 parts of butyl acrylate, 2.5-3.5 parts of 4-hydroxybutyl acrylate, 3 permillage of methyl methacrylate, 3 permillage of isostearyl acrylate, 0.6-0.8 permillage of initiator and 65-75 parts of second solvent.

2. The folded OCA adhesive with high adhesion to UTG material of claim 1, wherein said OCA glue is prepared by:

mixing isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate and isostearyl acrylate with part of the second solvent according to the weight ratio, introducing nitrogen, stirring under heating, adding part of initiator, heating and stirring for reaction; then heating up for reaction; adding the rest initiator, and continuing to react at the temperature; and cooling after the reaction is finished, and adding the rest of the second solvent for dilution to obtain the OCA glue.

3. The folded OCA adhesive with high adhesion to UTG material of claim 2, wherein said OCA glue is prepared by:

mixing isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate and isostearyl acrylate with part of the second solvent according to the weight ratio, introducing nitrogen, stirring at 60-62 ℃ for at least 30 minutes, adding part of initiator, maintaining the temperature, and stirring for reacting for 1-4 hours; then heating to 63-68 ℃ for reaction for 3-4 h; adding the rest initiator, raising the temperature to 70-72 ℃ and continuing to react for 3-6 hours; and cooling to room temperature, and adding the rest of the second solvent for dilution to obtain the OCA glue.

4. The folded OCA adhesive with high adhesion to UTG material of claim 3, wherein said OCA glue is prepared by:

mixing isooctyl acrylate, butyl acrylate, 4-hydroxybutyl acrylate, methyl methacrylate and isostearyl acrylate with part of the second solvent according to the weight ratio, introducing nitrogen, stirring at 60-62 ℃ for at least 30 minutes, adding part of initiator, maintaining the temperature, and stirring for reacting for 2 hours; then heating to 65 ℃ for reaction for 3 hours; adding the rest initiator, raising the temperature to 70-72 ℃ and continuing to react for 5 hours; cooling to room temperature, adding the rest of the second solvent for dilution, and obtaining the OCA glue with the solid content of 25-30%.

5. The folded OCA adhesive of claim 1, wherein the first solvent and the second solvent are both ethyl acetate.

6. The folded OCA adhesive of claim 1 having high tack properties to UTG material, wherein the initiator is AIBN.

7. The folded OCA adhesive of claim 1 having high tack properties to UTG material, wherein the thermal curing agent is hexamethylene diisocyanate.

8. A folded OCA film having high adhesion properties to UTG material, characterized in that it is prepared by using the OCA adhesive according to any one of claims 1 to 7.

9. A method of preparing a folded OCA film having high adhesion properties to UTG material as claimed in claim 8, comprising the steps of:

s1, mixing OCA glue, a thermosetting agent and a first solvent, and uniformly stirring to obtain a folded OCA adhesive with high viscosity to UTG materials;

s2, coating the folded OCA adhesive on a first release film, controlling the thickness of the dry adhesive to be 30-80 mu m, putting the first release film into an oven, drying the first release film at 110-130 ℃ for 1-4min, attaching a second release film on the adhesive surface of the formed dry adhesive layer, and curing the second release film at 50-70 ℃ for 24-48h to obtain the folded OCA adhesive film with high adhesive property to UTG materials.

10. The method for preparing a folded OCA film having high adhesion properties to UTG material according to claim 9, comprising the steps of:

s1, mixing OCA glue, a thermosetting agent and a first solvent under the conditions of 23-25 ℃ and 50+/-3% of humidity, and uniformly stirring to obtain a folded OCA adhesive with high viscosity to UTG materials;

s2, coating the folded OCA adhesive on a first release film, controlling the thickness of the dry adhesive to be 50 mu m, putting the first release film into an oven, heating the dry adhesive to 120 ℃ from 25 ℃, then drying the second release film at 120 ℃ for 2min, attaching a second release film on the adhesive surface of the formed dry adhesive layer, and curing the second release film at 60 ℃ for 36h to obtain the folded OCA adhesive film with high viscosity to UTG materials.