CN117887359A - OCA optical cement and preparation method and application thereof - Google Patents

Abstract

The application discloses OCA optical cement, a preparation method and application thereof, and belongs to the technical field of high polymer materials. The raw materials comprise, by weight, 20-40 parts of alkyl acrylate monomer, 15-40 parts of acrylate monomer with hydroxyl, 10-30 parts of organosiloxane monomer, 10-25 parts of high refractive index monomer, 10-20 parts of reactive diluent, 0.5-1 part of chain transfer agent, 0.5-4 parts of photoinitiator, 0.1-1 part of ultraviolet absorber and 0.1-1 part of antioxidant. The optical adhesive has the advantages that the light transmittance is more than 99%, the haze value is not more than 0.1%, the refractive index is more than 1.55, the optical adhesive has excellent optical performance and high-temperature and high-humidity resistance, the primary adhesion and the peeling force are moderate, the holding adhesion is more than 240 hours, the display screen cannot move and fall off after being attached, and the optical adhesive has good mechanical properties; the solid content is 100%, the glue coating thickness is only 25 mu m, the coating amount is small, and the environment-friendly performance is excellent.

Description

OCA optical cement and preparation method and application thereof

Technical Field

The application belongs to the technical field of high polymer materials, and particularly relates to an OCA optical cement and a preparation method and application thereof.

Background

With the rapid development of the intelligent electronic industry, a touch display screen is widely used as a simple and convenient input device. The full-lamination technology can be used for seamlessly laminating the screen, so that the mechanical reliability, optical effect and touch sensitivity of the display screen are obviously improved, and the full-lamination technology becomes a mainstream development trend of the industry. As an indispensable material in the full-lamination technology, the performance requirements of the market on the optically transparent adhesive (Optically CLEAR ADHESIVE, OCA) are also increasing. In general, OCA optical adhesives should meet excellent optical properties (refractive index of 1.50 or more, while enabling transmittance of 90% or more in a specified light wave range); the adhesive property and the optical property are good under extreme conditions (high temperature, high humidity, low temperature, etc.); aging resistance, difficult yellowing and the like.

Chinese patent No. 110776855B discloses a UV light curing high light transmittance optical cement and a preparation method thereof. The raw material formula of the high-light-transmittance optical transparent adhesive comprises, by weight, 20-50 parts of (methyl) acrylic acid alkyl ester, 15-40 parts of (methyl) acrylic acid hydroxyalkyl ester, 10-15 parts of polar monomer containing N atoms, 10-20 parts of reactive diluent, 0.1-2 parts of chain transfer agent, 0.5-1 part of thermal initiator, 0.5-1 part of photoinitiator and 0.6-1.8 parts of other auxiliary agents. The obtained product has the advantages of high light transmittance, low haze and the like. However, the thickness of the adhesive coating is 50 μm, and the higher fitting thickness limits the practical application of the adhesive coating in high-end optical adhesives, which is probably caused by the lower refractive index of the obtained adhesive film.

The Chinese patent application CN113025240A provides a UV solvent-free optical cement and a preparation method thereof, wherein the UV solvent-free optical cement comprises 50-95 parts of acrylic acid alkyl ester, 1-30 parts of acrylic acid ester with an aliphatic cyclic side chain, 1-30 parts of acrylic acid ester with a polar cyclic side chain, 1-30 parts of acrylic acid ester containing a polar group, 0.01-5 parts of polyfunctional acrylic acid ester and 0.02-2.0 parts of photoinitiator. The polar ring structure and the nonpolar ring structure are introduced to carry out molecular design, the compatibility of the polar part and the nonpolar part in the polymer chain segment is enhanced while the glass transition temperature of the material is controlled, so that the optical performance, the high-temperature and high-humidity resistance and the water boiling and whitening resistance of the optical transparent adhesive film can be improved, and the optical transparent adhesive film has good ink filling performance and easy reworkability. However, the adhesive film obtained by the method has a glue coating thickness of 100 μm and a light transmittance of only about 92%. These performance parameters do not meet the requirements of high end equipment for OCA films with low thickness and light transmittance above 99%.

Disclosure of Invention

In view of the above, the application provides an OCA optical adhesive, a preparation method and application thereof, and aims to solve the technical problems that the OCA optical adhesive has low refractive index and low light transmittance and cannot meet the requirement of high-end OCA optical adhesive.

On one hand, the application provides an OCA optical adhesive, which comprises the following component materials in parts by weight:

Optionally, the parts by weight of alkyl acrylate monomer in the raw material formulation are selected from any of 20, 22, 25, 28, 30, 32, 35, 38, 40 parts or a range of values between any two; the parts of the acrylate monomer with hydroxyl are selected from any value or range value between any two of 15, 18, 20, 22, 25, 28, 30, 32, 35, 38 and 40 parts; the usage parts of the organosiloxane monomers are selected from any value or range value between any two of 10, 12, 15, 18, 20, 22, 25, 28 and 30 parts; the parts of the high-folding monomer are selected from any value or range value between any two of 10, 12, 15, 18, 20, 22 and 25 parts; the part of the chain transfer agent is any value or a range value between any two of 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 parts; the parts of the photoinitiator used are any value or range of values between any two of 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0, 3.2, 3.5, 3.8 and 4 parts; the ultraviolet light absorber is selected from any value or range value between any two of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1 parts; the antioxidant is selected from any value or range value between any two of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1 parts; the parts of the reactive diluent used are selected from any value or range of values between any two of 10, 12, 15, 18 and 20 parts.

Optionally, the alkyl acrylate monomer is selected from one or more of methyl acrylate, ethyl acrylate, isopropyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate, isobornyl acrylate, 2-methylbutyl acrylate, 4-methyl-2-pentyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, t-butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and isopropyl methacrylate.

Optionally, the acrylate monomer with hydroxyl is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

Optionally, the organosiloxane monomer is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-t-butoxysilane, vinyltriacetoxysilane.

Optionally, the high refractive index monomer is selected from one or more of acryloylmorpholine, o-phenylphenoxyethyl acrylate, phenoxybenzyl acrylate and biphenylmethanol acrylate.

Optionally, the reactive diluent is selected from one or more of glycidyl methacrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol diacrylate, trimethylolpropane triacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, cyclohexanedimethanol di (meth) acrylate, alkoxylated cyclohexanedimethanol diacrylate, ethoxylated bisphenol a di (meth) acrylate, neopentyl glycol diacrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and urethane di (meth) acrylate.

Alternatively, the chain transfer agent is selected from dodecyl mercaptan.

Optionally, the photoinitiator is selected from one or more of methyl benzoylformate, 2-hydroxy-2-methylphenyl propane-1-one, 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, 1-hydroxycyclohexylphenyl ketone, 2, 4-diethylthioxanthone or alpha-hydroxyisobutyrophenone.

Optionally, the ultraviolet light absorber is selected from one or more of ultraviolet light absorber phenyl salicylate, ultraviolet light absorber UV-P, ultraviolet light absorber UV-329, ultraviolet light absorber UV-O, ultraviolet light absorber UV531 and ultraviolet light absorber UV 234.

Optionally, the antioxidant is selected from one or more of dibutyl hydroxytoluene, tertiary butyl hydroquinone, antioxidant BHA and BHT.

Optionally, the transmittance of the OCA optical adhesive is 99% -99.9%; haze value is less than or equal to 0.1%; the refractive index is 1.55-1.56.

Optionally, the OCA optical cement has a solids content of 100%; the glue thickness is 22-28 mu m.

Optionally, the OCA optical cement has a glue thickness of 25 μm.

The organic silicon modified acrylic ester OCA optical adhesive provided by the application has the following advantages: high refractive index (1.55-1.56), high light transmittance (> 99%), low haze, high temperature and high humidity resistance, good adhesion performance, and environmental friendliness.

In a second aspect, the present application provides a method for preparing the OCA optical adhesive, which comprises the following steps:

s1: preparing each component according to the raw material formula of the OCA optical adhesive;

s2: mixing the alkyl acrylate monomer, the acrylate monomer with hydroxyl, the organosiloxane monomer, the high refractive index monomer and the chain transfer agent, stirring, and performing heating reaction to obtain an intermediate product A;

S3: mixing the intermediate product A, the photoinitiator, the ultraviolet light absorber and the antioxidant in the step S2, and performing partial photopolymerization in an inactive atmosphere to obtain a prepolymer; mixing the prepolymer with the reactive diluent to obtain an intermediate product B;

S4: and (3) coating the intermediate product B in the step (S3) on a release film, curing, and adhering a release film on the cured material to obtain the organosilicon modified acrylic ester OCA optical cement.

Optionally, in step S2, the temperature of the heating reaction is 70-75 ℃, the time of the heating reaction is 2-3 h, and the stirring rotation speed is 70-80 r/min.

Optionally, in step S2, the temperature of the heating reaction is selected from any value or range of values between any two of 70 ℃, 71 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃; the heating reaction time is selected from any value or range value between any two of 2h, 2.2h, 2.5h, 2.8h and 3 h; the stirring rotating speed is selected from any value or range value between any two of 70r/min, 75r/min and 80 r/min.

Optionally, in step S3, after partial photopolymerization, a prepolymer with a polymerization rate of 10-15% is obtained; the non-reactive atmosphere comprises a nitrogen atmosphere.

Optionally, in step S4, the curing is curing with an ultraviolet lamp; the ultraviolet lamp curing conditions are as follows: the wavelength is 280-420 mm, and the energy is 4000mJ/cm ².

Optionally, in step S1, each raw material of the OCA optical adhesive is dried.

Optionally, in step S1, the drying process of each raw material includes:

Vacuum dehydrating the alkyl acrylate monomer, the acrylate monomer with hydroxyl, the organosiloxane monomer, the high-folding monomer and the reactive diluent for 1-2 h respectively, setting the temperature to be 0-10 ℃ above the boiling point temperature of each monomer, and dehydrating all the monomers with molecular sieves for 12-24 h respectively after cooling;

And (3) placing the photoinitiator, the chain transfer agent, the ultraviolet light absorber and the antioxidant in a vacuum oven at 50-80 ℃ for drying for 12-24 hours.

The OCA optical adhesive provided by the application is a sandwich structure of a release film, a prepolymer and a release film, wherein the synthesized prepolymer is uniformly coated on the release film; and then curing the film by Ultraviolet (UV) light irradiation, and uncovering the release film when in use, so that the film can be applied to electronic equipment comprising a touch screen panel and a liquid crystal screen in a full-lamination way.

The application provides a specific OCA optical cement implementation method, which comprises the following steps:

(1) According to parts by weight, adding 20-40 parts of dried alkyl acrylate monomer, 15-40 parts of acrylate monomer with hydroxyl, 10-30 parts of organic siloxane monomer, 10-25 parts of high-folding monomer and 0.5-1 part of chain transfer agent into a four-neck flask, heating to 70-75 ℃, and reacting for 2-3 hours under the condition of the rotating speed of 70-80 r/min.

(2) Then adding 0.5-4 parts of photoinitiator, 0.1-1 parts of ultraviolet light absorber and 0.1-1 parts of antioxidant, and carrying out partial photopolymerization in nitrogen atmosphere to obtain the prepolymer with the polymerization rate of 10-15%. And adding 10-20 parts of reactive diluent into the prepolymer, uniformly mixing, coating on a release film, curing by an ultraviolet lamp, and attaching another release film to obtain the organosilicon modified acrylic ester OCA optical cement.

The organic silicon modified acrylic ester OCA optical adhesive prepared by the method has the light transmittance of more than 99%, the haze value of not more than 0.1%, the refractive index of more than 1.55 and excellent optical performance; after high-temperature and high-humidity testing, the obtained organosilicon modified acrylic ester OCA optical adhesive can still maintain excellent optical performance and has excellent high-temperature and high-humidity resistance; the initial adhesion and the peeling force are moderate, the holding adhesion is more than 240 hours, the display screen cannot move and fall off after being attached, and the display screen has good mechanical properties; the solid content is 100%, the glue coating thickness is only 25 mu m, the coating amount is small, the process is simple, the energy consumption is low, and the environment-friendly performance is excellent.

In a third aspect, the present application provides an application of the OCA optical adhesive or the OCA optical adhesive obtained by the preparation method in touch screen panels or liquid crystal display electronic devices.

Compared with the prior art, the application has the following beneficial effects:

(1) The organic silicon monomer is introduced into the optical adhesive raw material, and the bond energy (438 kJ/mol) of the silicon-oxygen bond is larger than the bond energy (348 kJ/mol) of the carbon-carbon single bond in the acrylic main chain, so that the high temperature resistance of the OCA optical adhesive can be improved after the organic silicon is modified, and the application range of the optical adhesive can be further widened. The high-refraction monomer is further added into the optical adhesive raw material, so that the refractive index of the OCA optical adhesive can be effectively improved, and the problem of excessive thickness of an adhesive film caused by poor refractive index of the conventional optical adhesive is solved.

(2) The application adds the reactive diluent into the optical collagen material, effectively connects various monomers together, improves the crosslinking degree, can effectively improve the adhesive holding force of the adhesive film, and has proper proportion of soft and hard monomers and proper initial adhesive force. In addition, the solid content of the OCA optical adhesive is 100%, and the OCA optical adhesive has more excellent environmental protection performance.

(3) When the light transmittance of the optical adhesive exceeds 90%, a trace amount of water vapor in the adhesive film can greatly influence the light transmittance of the OCA optical adhesive, so that the water vapor in the adhesive film is strictly controlled to improve the light transmittance of the adhesive film. All products of the application are dehydrated, so that the moisture in the adhesive film is greatly reduced. The effect of hydrophilic hydroxyl in the acrylate monomer with hydroxyl is utilized, so that extremely trace water vapor in the OCA optical adhesive is uniformly dispersed, cloud point is not generated, the light transmittance of the optical adhesive is further improved, and the haze of the optical adhesive is reduced. In addition, the ultraviolet absorber and the antioxidant are added, so that the yellowing resistance and the light transmittance of the optical adhesive can be effectively improved.

Detailed Description

The application will be further illustrated with reference to specific examples. The following description is given of several embodiments of the present application and is not intended to limit the application in any way, and although the application is disclosed in the preferred embodiments, it is not intended to limit the application, and any person skilled in the art will make some changes or modifications with the technical content disclosed in the above description equivalent to the equivalent embodiments without departing from the scope of the technical solution of the present application.

Unless otherwise indicated, all starting materials in the examples of the present application were purchased commercially and used without any particular treatment.

Example 1

(1) According to parts by weight, adding 20 parts of dried methyl methacrylate, 20 parts of hydroxyethyl acrylate, 10 parts of vinyl trimethoxy silane, 15 parts of biphenyl methanol acrylic ester and 0.5 part of dodecyl mercaptan into a four-neck flask, heating to 70-75 ℃, and reacting for 2-3 hours under the condition of the rotating speed of 70-80 r/min.

(2) Then adding 2 parts of 2-hydroxy-2-methyl phenyl propane-1-ketone, 0.5 part of ultraviolet absorbent UV531 and 0.5 part of tertiary butyl hydroquinone, and carrying out partial photopolymerization in nitrogen atmosphere to obtain a prepolymer with the polymerization rate of 10-15%; then adding 15 parts of 1, 6-hexanediol di (methyl) acrylic ester into the prepolymer, uniformly mixing, coating on a release film, curing by an ultraviolet lamp, and attaching another release film to obtain the organic silicon modified acrylic ester OCA optical adhesive.

Example 2

(1) According to parts by weight, adding 20 parts of dried ethyl methacrylate, 20 parts of ethyl acrylate, 15 parts of hydroxypropyl acrylate, 30 parts of vinyl triethoxysilane, 25 parts of o-phenylphenoxyethyl acrylate and 0.5 part of dodecyl mercaptan into a four-neck flask, heating to 70-75 ℃, and reacting for 2-3 hours under the condition of the rotating speed of 70-80 r/min.

(2) Then adding 4 parts of methyl benzoyl formate, 1 part of ultraviolet absorbent UV-O and 1 part of dibutyl hydroxy toluene, and carrying out partial photopolymerization in a nitrogen atmosphere to obtain a prepolymer with the polymerization rate of 10-15%; and adding 20 parts of glycidyl methacrylate into the prepolymer, uniformly mixing, coating on a release film, curing by an ultraviolet lamp, and attaching another release film to obtain the organic silicon modified acrylic ester OCA optical adhesive.

Example 3

(1) According to parts by weight, adding 40 parts of dried isobornyl acrylate, 40 parts of hydroxypropyl methacrylate, 30 parts of vinyl triacetoxy silane, 15 parts of phenoxybenzyl acrylate and 0.5 part of dodecyl mercaptan into a four-neck flask, heating to 70-75 ℃, and reacting for 2-3 hours under the condition of the rotating speed of 70-80 r/min.

(2) 2 Parts of 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, 0.5 part of ultraviolet absorbent salicyl ester phenyl ester and 0.5 part of antioxidant BHA are added, and partial photopolymerization is carried out in nitrogen atmosphere, so as to obtain a prepolymer with the polymerization rate of 10-15 percent; and adding 15 parts of trimethylolpropane triacrylate into the prepolymer, uniformly mixing, coating on a release film, curing by an ultraviolet lamp, and attaching another release film to obtain the organosilicon modified acrylic ester OCA optical cement.

Example 4

(1) According to the weight portion, 30 portions of dried isoamyl acrylate, 25 portions of hydroxypropyl methacrylate, 25 portions of vinyl tri-tert-butoxysilane, 20 portions of biphenyl methanol acrylic ester and 1 portion of dodecyl mercaptan are added into a four-neck flask, the temperature is raised to 70-75 ℃, and the reaction is carried out for 2-3 hours under the condition of the rotating speed of 70-80 r/min.

(2) Then adding 3 parts of 2, 4-diethyl thioxanthone or alpha-hydroxy isobutyryl benzene, 0.1 part of ultraviolet absorber UV234 and 0.1 part of antioxidant BHT, and carrying out partial photopolymerization in nitrogen atmosphere to obtain a prepolymer with the polymerization rate of 10-15%. And adding 15 parts of tripropylene glycol diacrylate into the prepolymer, uniformly mixing, coating on a release film, curing by an ultraviolet lamp, and attaching another release film to obtain the organosilicon modified acrylic ester OCA optical cement.

Comparative example 1

Comparative example 1 differs from example 1 in that no organosiloxane monomer was added to the starting material.

Comparative example 2

Comparative example 2 differs from example 1 in that no high-refraction monomer was added to the starting material.

Comparative example 3

Comparative example 3 differs from example 1 in that no reactive diluent was added to the feed.

The thickness of the films prepared in examples 1 to 4 and comparative examples 1 to 3 after photo-curing was 25. Mu.m, before mechanical and optical property tests were carried out.

When the mechanical property test is carried out, the initial adhesion is tested according to national standard GB/T4852-2002, the holding adhesion is tested according to national standard GB/T4851-1998, and the stripping force is tested according to national standard GB/T2792-1998.

In the optical performance test, the adhesive film was first transferred onto an optical glass, and then the transmittance, refractive index and haze were measured using a Lambda950 type ultraviolet-visible spectrophotometer, an Abbe refractometer and a haze meter, respectively. In the high temperature and high humidity test, the obtained adhesive film was first transferred between two pieces of optical glass, then placed in an environment at 90 ℃ and 85% humidity for 30d, and then tested for light transmittance using a Lambda950 type uv-vis spectrophotometer.

The samples of examples 1 to 4 and comparative examples 1 to 3 were subjected to comprehensive performance analysis according to the above test methods; the results obtained are shown in Table 1:

TABLE 1 sample Performance test Table for examples 1-4 and comparative examples 1-3

From the data in table 1, it can be seen that: firstly, the organosilicon modified acrylic ester OCA optical adhesive prepared in the embodiments 1-4 of the application has moderate initial adhesion (No. 6-7 balls) due to moderate proportion of soft and hard monomers, and the value accords with the ideal value of the international high-end OCA optical adhesive film and meets the industry requirement. In addition, as the reactive diluents are added in the embodiments 1 to 4, the adhesive holding power of the adhesive films is greatly increased, and the crosslinking degree of the adhesive films can be improved due to the reactive diluents. It should be noted that, although the addition of the reactive diluent resulted in a decrease in the peel force and the holding power, the adhesive films obtained in examples 1 to 4 still met the industry requirements in both peel force and initial adhesion. In fact, reworking is also a concern for the optical film, so that proper peel force is advantageous for reworkability of the film obtained in the examples.

Secondly, the optical transmittance of the OCA optical adhesive films prepared in the embodiments 1 to 4 is more than 99%, the haze value is not more than 0.1%, and the refractive index is more than 1.55; this is mainly because all raw materials are dehydrated, so the water vapor in the adhesive film is very little; and because of the addition of the hydroxyl-containing acrylate monomer to the formulation, this will allow very little water vapor to be dispersed evenly without causing cloud point formation. In addition, the ultraviolet absorber and the antioxidant are added, so that the yellowing resistance of the adhesive film is improved. Therefore, the OCA optical adhesive film prepared by the application has good optical performance.

Then, in examples 1 to 4 of the present application, since the silicone modification was employed, there was substantially no difference in optical properties of the adhesive films after the high temperature and high humidity treatment. The molecular chain of the adhesive film obtained after the organic silicon modification mainly contains a silicon-oxygen bond, and the bond energy (438 kJ/mol) of the silicon-oxygen bond is larger than the bond energy (348 kJ/mol) of a carbon-carbon single bond in an acrylic main chain, so that the high temperature resistance of the adhesive film in the embodiment is improved.

Finally, the solid content of the organic silicon modified acrylic ester optical adhesive is 100%, so that the environment-friendly performance of the organic silicon modified acrylic ester optical adhesive is obviously improved compared with that of the existing optical adhesive in the market. The adhesive film obtained by the application has excellent comprehensive performance, particularly has light transmittance of more than 99%, haze value of not more than 0.1% and refractive index of more than 1.55, and successfully solves the problem that the optical performance of the Chinese application patent application CN113025240A can not meet the requirement of high-end optical adhesive. More importantly, the thickness of the adhesive film prepared by the application is only 25 mu m, and the lower thickness can enable the application occasion of the optical adhesive. Meanwhile, compared with the optical cement with the thickness of 50 mu m provided by the Chinese application patent CN110776855B, the thickness of the optical cement obtained by the application is greatly reduced on the basis of ensuring that the mechanical property and the optical property are not reduced.

In conclusion, the organic silicon modified acrylic ester OCA optical adhesive prepared by the application has excellent optical performance, good mechanical property and excellent high-temperature and high-humidity resistance, and particularly importantly, the low thickness of the organic silicon modified acrylic ester OCA optical adhesive can lead the optical adhesive to have wider application prospect.

While the application has been described in terms of preferred embodiments, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the scope of the application, and it is intended that the application is not limited to the specific embodiments disclosed.

Claims (10)

1. The OCA optical adhesive is characterized by comprising the following component materials in parts by weight:

2. The OCA optical adhesive of claim 1, wherein the alkyl acrylate monomer is selected from one or more of methyl acrylate, ethyl acrylate, isopropyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-butyl acrylate, isobornyl acrylate, 2-methylbutyl acrylate, 4-methyl-2-pentyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, t-butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and isopropyl methacrylate;

Preferably, the acrylate monomer with hydroxyl is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

3. The OCA optical adhesive of claim 1, wherein the organosiloxane monomer is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-t-butoxysilane, and vinyltriacetoxysilane.

4. The OCA optical adhesive of claim 1, wherein the high refractive index monomer is selected from one or more of acryloylmorpholine, o-phenylphenoxyethyl acrylate, phenoxybenzyl acrylate and biphenylmethanol acrylate.

5. The OCA optical adhesive of claim 1, wherein the reactive diluent is selected from one or more of glycidyl methacrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol diacrylate, trimethylolpropane triacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, cyclohexanedimethanol di (meth) acrylate, alkoxylated cyclohexanedimethanol diacrylate, ethoxylated bisphenol a di (meth) acrylate, neopentyl glycol diacrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and urethane di (meth) acrylate;

preferably, the chain transfer agent is selected from dodecyl mercaptan;

Preferably, the photoinitiator is selected from one or more of methyl benzoylformate, 2-hydroxy-2-methylphenyl propane-1-one, 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, 1-hydroxycyclohexylphenyl ketone, 2, 4-diethylthioxanthone or alpha-hydroxyisobutyrophenone;

Preferably, the ultraviolet light absorber is selected from one or more of ultraviolet light absorber phenyl salicylate, ultraviolet light absorber UV-P, ultraviolet light absorber UV-329, ultraviolet light absorber UV-O, ultraviolet light absorber UV531 and ultraviolet light absorber UV 234;

Preferably, the antioxidant is selected from one or more of dibutyl hydroxytoluene, tertiary butyl hydroquinone, antioxidant BHA and BHT.

6. The OCA optical cement according to claim 1, wherein the transmittance of the OCA optical cement is 99% to 99.9%; haze value is less than or equal to 0.1%; the refractive index is 1.55-1.56;

preferably, the solid content of the OCA optical cement is 100%; the glue thickness is 22-28 mu m.

7. The method for preparing an OCA optical cement according to any one of claims 1 to 6, characterized in that the method comprises the steps of:

S1: preparing each component according to the raw material formula of the OCA optical adhesive;

S2: mixing the alkyl acrylate monomer, the acrylate monomer with hydroxyl, the organosiloxane monomer, the high refractive index monomer and the chain transfer agent, and heating for reaction to obtain an intermediate product A;

S3: mixing the intermediate product A, the photoinitiator, the ultraviolet light absorber and the antioxidant in the step S2, and performing partial photopolymerization in an inactive atmosphere to obtain a prepolymer; mixing the prepolymer with the reactive diluent to obtain an intermediate product B;

S4: and (3) coating the intermediate product B in the step (S3) on a release film, curing, and adhering a release film on the cured material to obtain the organosilicon modified acrylic ester OCA optical cement.

8. The method for preparing an OCA optical cement according to claim 7, wherein in step S2, the temperature of the heating reaction is 70-75 ℃, the time of the heating reaction is 2-3 hours, and the stirring rotation speed is 70-80 r/min;

Preferably, in the step S3, after partial photopolymerization, a prepolymer with a polymerization rate of 10-15% is obtained; the inactive atmosphere comprises a nitrogen atmosphere;

Preferably, in step S4, the curing is curing with an ultraviolet lamp; the ultraviolet lamp curing conditions are as follows: the wavelength is 280-420 mm, and the energy is 4000mJ/cm ².

9. The method for preparing OCA optical cement according to claim 7, wherein in step S1, each raw material of the OCA optical cement is dried;

preferably, in step S1, the drying process of each raw material includes:

Vacuum dehydrating the alkyl acrylate monomer, the acrylate monomer with hydroxyl, the organosiloxane monomer, the high-folding monomer and the reactive diluent for 1-2 h respectively, setting the temperature to be 0-10 ℃ above the boiling point temperature of each monomer, and dehydrating all the monomers with molecular sieves for 12-24 h respectively after cooling;

And (3) placing the photoinitiator, the chain transfer agent, the ultraviolet light absorber and the antioxidant in a vacuum oven at 50-80 ℃ for drying for 12-24 hours.

10. The OCA optical cement of any one of claims 1 to 6 or the OCA optical cement obtained by the preparation method of any one of claims 7 to 9, for use in touch screen panels or liquid crystal display electronic devices.