CN118791998A - Ultraviolet light-cured flame-retardant acrylic filling adhesive, light-cured adhesive film and preparation method thereof - Google Patents

Abstract

The present invention discloses a UV-curable flame-retardant acrylic filler, a photocurable adhesive film and a preparation method thereof, wherein the filler comprises the following raw material components by weight: 1-6 parts of flame-retardant modified photocurable acrylic resin, 20-40 parts of acrylic resin, 40-70 parts of reactive diluent, 1-5 parts of photoinitiator, and 0.1-3 parts of auxiliary agent. The UV-curable flame-retardant acrylic filler of the present invention has the characteristics of low viscosity, low shrinkage, high light transmittance, high refractive index, no yellowing, and excellent flame retardant properties; the filler formula of the present invention introduces flame-retardant modified acrylic resin, so that the material has excellent flame retardancy, and the amount of introduction is controlled to retain the extremely high light transmittance of the material. In addition, the flame retardant element (phosphorus nitrogen) therein increases the refractive index of the material, making it closer to the refractive index of glass, so as to meet the performance application requirements of the material of the present invention.

Description

Ultraviolet light-cured flame-retardant acrylic filling adhesive, light-cured adhesive film and preparation method thereof

Technical Field

The invention relates to the field of OCA optical adhesive materials, and in particular to an ultraviolet light-cured flame-retardant acrylic filling adhesive, a light-cured adhesive film and a preparation method thereof.

Background Art

With the rapid development of the national economy, people have higher and higher requirements for the use of optoelectronic information equipment such as mobile phones and tablets, and the average use time is getting longer and longer. For example, the high-intensity use of mobile phones is accompanied by a long charging and discharging process, which in turn generates a lot of heat, posing great risks of explosions and fires. In the field of display screens, most of the current display screens are bonded with OCA optical adhesive films with excellent performance. However, they also have disadvantages such as poor flow performance, easy generation of bubbles during bonding, easy adsorption of dust and impurities, low bonding efficiency for large sizes, and poor explosion-proof effect of the screen after bonding.

In order to solve the problem of OCA optical film lamination, the display screen also uses full lamination technology, that is, the cover plate and the sensor or module are directly seamlessly laminated with liquid optical adhesive OCR. Full lamination technology has the advantages of better display effect, screen isolation of dust and water vapor, reduced noise interference, thinner body, simplified assembly, and at the same time helps narrow frame design. OCR is colorless and transparent, has high light transmittance, good bonding strength, can be cured at room temperature, medium temperature or UV conditions, and has the characteristics of small curing shrinkage and yellowing resistance; but due to the curing process, there will be a certain molding shrinkage, which may cause yellowing, warping, abnormal OCR glue thickness and other defects. The commonly used resin components of OCA and OCR are epoxy resin, acrylate resin, silicone resin, polyurethane resin, etc. Most of them have a common disadvantage: flammable.

Patent No. CN115851214A provides an impact-resistant optical filling adhesive for display screens. The invention introduces an organosilicon group by connecting one end of isocyanate with methylsilanol, and introduces a diene segment by connecting the other end with hydroxyl-containing acrylic isoprene/butadiene, thereby obtaining organosilicon-modified acrylic isoprene and organosilicon-modified acrylic butadiene. The prepolymer also carries functional groups or segments such as polyurethane, organosilicon, polyacrylic acid, EVOH and polydiene, and has the characteristics of a thermoplastic elastomer. The optical adhesive provided has the characteristics of high clarity, high light transmittance, high adhesion, high weather resistance, water resistance, high temperature resistance, controlled thickness, long service life, etc., and provides a strong buffering effect for the display screen after curing into a film, but does not involve the flame retardant properties of the glue.

Patent No. CN113603864B discloses a photocurable phosphorus-nitrogen flame-retardant acrylic resin and a photocurable coating prepared therefrom. Patent No. CN113880882B also discloses a phosphorus-nitrogen photocurable flame-retardant acrylic resin and a flame-retardant ... The flame retardant coating of the invention has low cost, simple process, strong adhesion and mechanical properties, low viscosity, good wear resistance, excellent flame retardant, heat resistance, moisture resistance and other properties. Both of them have excellent flame retardant properties by introducing the synergistic effect of phosphorus and nitrogen, but both are applied to coatings, so they do not involve the study of the optical properties of the material. While improving the flame retardant properties, some optical properties of the material are reduced, resulting in some optical applications of the material being restricted.

Therefore, it is necessary to improve the existing technology to provide a more reliable solution.

Summary of the invention

The technical problem to be solved by the present invention is to provide a UV-curable flame-retardant acrylic filler, a light-cured adhesive film and a preparation method thereof in view of the deficiencies in the above-mentioned prior art. The UV-curable flame-retardant acrylic filler has low viscosity, high clarity, high light transmittance, high adhesion, excellent flame retardancy, heat resistance, moisture resistance and other properties, and the preparation method thereof has low cost and simple process.

To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: in the first aspect of the present invention, a UV-curable flame-retardant acrylic filler is provided, comprising the following raw material components in parts by weight: 1-6 parts of flame-retardant modified light-curable acrylate resin, 20-40 parts of acrylate resin, 40-70 parts of active diluent, 1-5 parts of photoinitiator, and 0.1-3 parts of auxiliary agent.

Preferably, the flame retardant modified photocurable acrylate resin is at least one selected from an organic phosphorus modified photocurable acrylate resin, an organic phosphorus nitrogen modified photocurable acrylate resin, and an organic phosphorus nitrogen sulfur modified photocurable acrylate resin.

Preferably, the acrylate resin is selected from one or more of epoxy acrylate, polyurethane acrylate, hyperbranched polyester acrylate, and epoxy soybean oil acrylate.

Preferably, the reactive diluent is selected from one or more of methyl (meth)acrylate, hydroxyethyl (meth)acrylate, isooctyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-phenoxyethyl methacrylate, isobornyl (meth)acrylate, n-butyl (meth)acrylate, lauryl (meth)acrylate, ethylene glycol dimethacrylate, ethoxylated bisphenol A diacrylate, 1,4-butanediol diacrylate, tricyclodecane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, tetraethylene glycol dimethacrylate, and tetrahydrofurfuryl (meth)acrylate.

Preferably, the photoinitiator is selected from one or more of 1173, 184, BP, TMO, and 819;

The auxiliary agent is selected from one or more of a silane coupling agent, a leveling agent, and a defoaming agent.

Preferably, the organophosphorus modified light-curable acrylate resin is prepared by the following method:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and glycidyl methacrylate are mixed in a three-necked flask at a molar ratio of 1:1, placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred. After 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is completely dissolved, the reaction is continued for 2 hours, and the product is taken out and cooled to obtain the organophosphorus modified light-curing acrylate resin.

Preferably, the organic phosphorus-nitrogen modified light-curable acrylate resin is prepared by the following method:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tri(2-hydroxyethyl)isocyanuric acid triacrylate are mixed in a three-necked flask at a molar ratio of 1:1, placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred. After 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is completely dissolved, the reaction is continued for 2 hours, and the product is taken out and cooled to obtain the organophosphorus modified light-curing acrylate resin.

Preferably, the organic phosphorus, nitrogen and sulfur modified light-curable acrylate resin is prepared by the following method:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and thiourea are mixed in a three-necked flask at a molar ratio of 1:1, 70 mL of pure water is added as a solvent, a constant temperature water bath of 95°C is placed, condensation reflux is performed, mechanical stirring is performed, and the reaction is performed for 8 hours; after the reaction is completed, the product is poured out, and the turbid solution is obtained by standing for 0.5 hours, and the solid product is washed twice with pure water. The obtained solid product is dried at 110°C for 10 hours, and the obtained white block product is ground into powder, and the product is mixed with acrylic acid at a molar ratio of 1:2 to amidate it, and the water product is distilled to obtain the organic phosphorus nitrogen sulfur modified light-curing acrylate resin.

The second aspect of the present invention provides a method for preparing the UV-curable flame-retardant acrylic filler as described above, comprising the following steps:

In a clean, low-humidity and light-proof environment, 1-6 parts of flame-retardant modified light-curable acrylate resin, 20-40 parts of acrylate resin, 40-70 parts of reactive diluent, 1-5 parts of photoinitiator and 0.1-3 parts of auxiliary agent are mixed by weight, and mechanically stirred at a speed of 250-1000 r/min for 15-60 minutes to obtain the UV-curable flame-retardant acrylic filling glue.

A third aspect of the present invention provides a photocurable adhesive film, which is prepared by the following method: the UV-curable flame-retardant acrylic filler described above is evenly coated on a substrate, and the photocurable adhesive film is obtained after UV-curing.

The beneficial effects of the present invention are:

The present invention provides a UV-curable flame-retardant acrylic filler and a light-cured adhesive film. The UV-curable flame-retardant acrylic filler has the characteristics of low viscosity, low shrinkage, high light transmittance, high refractive index, no yellowing, etc., and also has excellent flame retardant performance.

The flame retardant modified acrylate resin is introduced into the filling glue formula of the present invention, so that the material has excellent flame retardancy, and at the same time, the introduction amount is controlled to retain the extremely high light transmittance of the material.

The flame retardant modified acrylate resin introduced in the present invention not only provides flame retardant properties, but also its flame retardant elements (phosphorus and nitrogen) increase the refractive index of the material. The refractive index of ordinary acrylate resin (1.450-1.550) makes it closer to the refractive index of glass (1.470-1.700), thereby increasing the applicability of ordinary acrylate and being able to meet the performance application requirements of the material of the present invention.

DETAILED DESCRIPTION

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 invention provides an ultraviolet light-cured flame-retardant acrylic filling adhesive, which comprises the following raw material components in parts by weight: 1-6 parts of flame-retardant modified light-cured acrylic resin, 20-40 parts of acrylic resin, 40-70 parts of active diluent, 1-5 parts of photoinitiator and 0.1-3 parts of auxiliary agent.

In a preferred embodiment, the flame retardant modified light-curable acrylate resin is selected from at least one of an organic phosphorus modified light-curable acrylate resin, an organic phosphorus nitrogen modified light-curable acrylate resin, and an organic phosphorus nitrogen sulfur modified light-curable acrylate resin. The flame retardant modified light-curable acrylate resin is a homemade product, which has no effect or negligible effect on the transparency of the material. Specifically, the preparation method thereof is as follows.

1. The organophosphorus modified light-curing acrylate resin is prepared by the following method:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (flame retardant DOPO) and glycidyl methacrylate were mixed in a three-necked flask at a molar ratio of 1:1, placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred. After 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was completely dissolved, the reaction was continued for 2 hours. The product was taken out and cooled to obtain an organophosphorus-modified light-curing acrylate resin.

2. Organic phosphorus-nitrogen modified light-curing acrylate resin is prepared by the following method:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (flame retardant DOPO) and tri(2-hydroxyethyl)isocyanuric acid triacrylate were mixed in a three-necked flask at a molar ratio of 1:1, placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred. After 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was completely dissolved, the reaction was continued for 2 hours. The product was taken out and cooled to obtain an organophosphorus-modified light-curing acrylate resin.

3. Organic phosphorus, nitrogen and sulfur modified light-curing acrylate resin is prepared by the following method:

9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and thiourea were mixed in a three-necked flask at a molar ratio of 1:1, 70 mL of pure water was added as a solvent, and the mixture was placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred for 8 hours. After the reaction, the product was poured out and allowed to stand for 0.5 hours to obtain a turbid solution, which was washed twice with pure water. The obtained solid product was dried at 110°C for 10 hours, and the obtained white block product was ground into powder. The product was mixed with acrylic acid at a molar ratio of 1:2 to amidate it, and the water product was distilled to obtain an organic phosphorus, nitrogen and sulfur modified light-curing acrylate resin.

In a preferred embodiment, the acrylate resin is selected from one or more of epoxy acrylate, polyurethane acrylate, hyperbranched polyester acrylate, and epoxy soybean oil acrylate.

In a preferred embodiment, the reactive diluent is selected from one or more of methyl (meth)acrylate, hydroxyethyl (meth)acrylate, isooctyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-phenoxyethyl methacrylate, isobornyl (meth)acrylate, n-butyl (meth)acrylate, lauryl (meth)acrylate, ethylene glycol dimethacrylate, ethoxylated bisphenol A diacrylate, 1,4-butanediol diacrylate, tricyclodecane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, tetraethylene glycol dimethacrylate, and tetrahydrofurfuryl (meth)acrylate. In the above representation, methyl (meth)acrylate can be methyl acrylate or methyl methacrylate, and the other substances with (methyl) have similar meanings.

In a preferred embodiment, the photoinitiator is selected from one or more of 1173, 184, BP, TMO, and 819.

In a preferred embodiment, the auxiliary agent is selected from one or more of a silane coupling agent, a leveling agent, and a defoaming agent.

The present invention also provides a method for preparing the above UV-curable flame-retardant acrylic filler, comprising the following steps:

In a clean, low-humidity and light-proof environment, 1-6 parts of flame-retardant modified light-curing acrylate resin, 20-40 parts of acrylate resin, 40-70 parts of active diluent, 1-5 parts of photoinitiator and 0.1-3 parts of auxiliary agent are mixed by weight, and mechanically stirred at a speed of 250-1000r/min for 15-60min to obtain a homogeneous solution, i.e., UV-curing flame-retardant acrylic filler.

The present invention also provides a photocurable adhesive film, which is prepared by the following method: the above ultraviolet light-curable flame-retardant acrylic filler is evenly coated on a substrate, and the photocurable adhesive film is obtained after ultraviolet light curing.

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.

The main raw materials used in the following examples and comparative examples include:

Example 1

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 6 parts of organophosphorus modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 61 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, i.e., UV-curing flame-retardant acrylic filler.

The organophosphorus modified light-curable acrylate resin is prepared by the following method:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, Shenzhen Jinlong Chemical Co., Ltd.) and glycidyl methacrylate (Shanghai MacLean Biochemical Technology Co., Ltd.) were mixed in a three-necked flask at a molar ratio of 1:1, placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred. After 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was completely dissolved, the reaction was continued for 2 hours. The product was taken out and cooled to obtain an organophosphorus-modified light-curing acrylate resin.

Example 2

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 1 part of organic phosphorus-nitrogen modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 66 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is as follows:

9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, Shenzhen Jinlong Chemical Co., Ltd.) and tri(2-hydroxyethyl)isocyanuric acid triacrylate (Sartomer, SR368 NS) were mixed in a three-necked flask at a molar ratio of 1:1, placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred; after DOPO was completely dissolved, the reaction was continued for 2 hours, the product was taken out and cooled, and an organic phosphorus-nitrogen modified light-curing acrylate resin was obtained.

Example 3

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 3 parts of organic phosphorus, nitrogen and sulfur modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 64 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus, nitrogen and sulfur modified light-curing acrylate resin is as follows:

9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, Shenzhen Jinlong Chemical Co., Ltd.) and thiourea (Guangzhou Chemical Reagent Factory) were mixed in a three-necked flask at a molar ratio of 1:1, and 70 ml of pure water was added as a solvent. The mixture was placed in a constant temperature water bath at 95°C, condensed and refluxed, and mechanically stirred for 8 hours. After the experiment, the mixture was poured into a beaker and allowed to stand for 0.5 hours to obtain a turbid solution, which was washed twice with pure water to obtain a solid powder. The powder was then dried in an oven at 110°C for 10 hours to obtain a white block of DOPO-THU, which was ground into powder for standby use. The product was dissolved in acrylic acid at a molar ratio of 1:2 to amidate it, and the water product was distilled off to obtain an organic phosphorus nitrogen sulfur modified light-curable acrylate resin.

Example 4

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 6 parts of organic phosphorus nitrogen modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 60 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that of Example 2.

Example 5

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 3 parts of organic phosphorus-nitrogen modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 64 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that of Example 2.

Example 6

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 3 parts of organic phosphorus nitrogen modified light-curing acrylate resin, 30 parts of bisphenol A epoxy acrylate, 64 parts of 1,4-butanediol diacrylate, 2 parts of photoinitiator 1173, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoaming agent BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that of Example 2.

Example 7

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 3 parts of organic phosphorus nitrogen modified light-curing acrylate resin, 30 parts of polyurethane acrylate, 64 parts of tricyclodecane dimethanol diacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that of Example 2.

Example 8

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 3 parts of organic phosphorus-nitrogen modified light-curing acrylate resin, 30 parts of epoxy soybean oil acrylate, 64 parts of hydroxyethyl methacrylate, 2 parts of photoinitiator 184, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that of Example 2.

Comparative Example 1

This example is basically the same as Example 1, except that: in this example, no flame retardant modified light-curing acrylate resin: organic phosphorus modified light-curing acrylate resin is added.

Comparative Example 2

This example is basically the same as Example 6, except that: no flame retardant modified light-curing acrylate resin is added: organic phosphorus nitrogen modified light-curing acrylate resin.

Comparative Example 3

This example is basically the same as Example 7, except that: no flame retardant modified light-curing acrylate resin is added: organic phosphorus nitrogen modified light-curing acrylate resin.

Comparative Example 4

This example is basically the same as Example 8, except that: no flame retardant modified light-curing acrylate resin is added: organic phosphorus nitrogen modified light-curing acrylate resin.

Comparative Example 5

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 7 parts of organic phosphorus-nitrogen modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 64 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation method of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that of Example 2.

Comparative Example 6

A UV-curable flame-retardant acrylic filler, the preparation method of which comprises the following steps:

In a clean, low-humidity and light-proof environment, accurately weigh by weight: 0.5 parts of organic phosphorus-nitrogen modified light-curing acrylate resin, 30 parts of hyperbranched polyester acrylate resin, 66.5 parts of isooctyl methacrylate, 2 parts of photoinitiator TMO, 0.5 parts of leveling agent BYK-3535, and 0.5 parts of defoamer BYK-011, mix them, and mechanically stir them at a speed of 500 r/min for 30 minutes to obtain a homogeneous solution, that is, to obtain a UV-curing flame-retardant acrylic filler.

The preparation of the organic phosphorus-nitrogen modified light-curable acrylate resin is consistent with that in Example 2.

The UV-curable flame-retardant acrylic filler prepared in the examples and comparative examples was prepared into corresponding photocurable adhesive films by the following method:

The UV-curable flame-retardant acrylic filler adhesive was evenly coated on a 50 μm release film substrate with a coating thickness of 50 μm. After being cured by UV light with a wavelength of 405 nm, a light-cured adhesive film was obtained for use. The irradiation energy was 3000 mj.

The UV-curable flame-retardant acrylic filler adhesive and the corresponding light-cured adhesive film prepared in the examples and comparative examples were subjected to performance tests according to the following test methods:

1. Viscosity is measured using a Brookfield DV2TLV viscometer according to GB/T 2794-2013;

2. The light transmittance is measured using a LAMBDA950 UV spectrophotometer according to GB/T 2410-2008;

3. The refractive index is measured using an Abbe refractometer according to GB/T 614-2021;

4. UL-94 grade is measured using a vertical burning tester in accordance with GB/T 5455-1997;

5. LOI is measured using an oxygen index meter in accordance with ASTM D2863-2017;

The test results are shown in Table 1:

Table 1

Note: "/" in Comparative Examples 1-4 indicates that the UL-94 grade was not achieved.

As can be seen from the above table, the results of Examples 1-3, 6-8 and Comparative Examples 1-4 show that the acrylate resin itself is flammable, and its LOI is all below 20. The present invention successfully introduces flame retardant elements into the acrylate resin by introducing a self-made flame retardant modified photocurable acrylate resin, and undergoes graft copolymerization reaction with other components under the action of photocuring, thereby providing excellent flame retardant properties for the acrylate photocurable adhesive film. The LOI test results of the embodiments are significantly increased, and can pass the UL-94 combustion test V-0 level.

The results of Examples 4-5 and Comparative Examples 5-6 show that the introduction amount of the homemade flame-retardant modified photocurable acrylate resin should be neither too high nor too low. When the introduction amount is too high, the content of the flame retardant element increases, and the chromaticity and absorbance of the element will increase accordingly, resulting in a decrease in the light transmittance of the resin material; when the introduction amount is too low, the flame retardant element does not provide enough flame retardant effect, resulting in poor flame retardant properties of the acrylate photocurable film, which cannot meet the V-0 level of the UL-94 test.

The flame retardant modified acrylate resin containing different flame retardant elements was selected for experimental comparison. The LOI results showed that the flame retardant effect of a single phosphorus element was worse than that of a multi-element synergistic flame retardant effect, and the phosphorus content needed to be increased to reach the V-0 level of the UL-94 test; while the introduction of a multi-element synergistic flame retardant modified light-cured acrylate resin only required the introduction of an extremely low phosphorus content to reach the V-0 level of the UL-94 test. The refractive index results showed that the introduction of phosphorus, nitrogen, and sulfur elements could all increase the refractive index of the material. This is because the atomic radius of phosphorus, nitrogen, and sulfur elements is large, the nucleus has a weak attraction to the outer electrons, is easily polarized, and has a high molar refractive index, thereby increasing the refractive index of the polymer; in addition, the flame retardant modified light-cured acrylate resin introduced contains heterocyclic groups such as benzene rings and heterophenanthrene rings, which can also effectively increase the refractive index. However, the sulfur element itself has a certain yellowing property, which is not good for some optical properties and durability of the product, and has a certain weakening of the synergistic flame retardant effect. Therefore, the present invention preferably uses an organic phosphorus and nitrogen synergistic flame retardant modified acrylate resin, which has a better effect.

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 ultraviolet light curing flame-retardant acrylic filling adhesive is characterized by comprising the following raw material components in parts by weight: 1-6 parts of flame-retardant modified photo-curing acrylate resin, 20-40 parts of acrylate resin, 40-70 parts of reactive diluent, 1-5 parts of photoinitiator and 0.1-3 parts of auxiliary agent.

2. The uv curable flame retardant acrylic filling compound according to claim 1, wherein the flame retardant modified photo curable acrylate resin is selected from at least one of an organophosphorus modified photo curable acrylate resin, an organophosphorus nitrogen sulfur modified photo curable acrylate resin.

3. The ultraviolet light curing flame-retardant acrylic filling adhesive according to claim 1, wherein the acrylic resin is one or more selected from epoxy acrylic ester, polyurethane acrylic ester, hyperbranched polyester acrylic ester and epoxy soybean oil acrylic ester.

4. The ultraviolet light curing flame-retardant acrylic filling adhesive according to claim 1, wherein the reactive diluent is selected from one or more of methyl (meth) acrylate, hydroxyethyl (meth) acrylate, isooctyl (meth) acrylate, tetrahydrofuranyl (meth) acrylate, 2-phenoxyethyl methacrylate, isobornyl (meth) acrylate, n-butyl (meth) acrylate, lauryl (meth) acrylate, ethylene glycol dimethacrylate, ethoxylated bisphenol a diacrylate, 1, 4-butanediol diacrylate, tricyclodecane dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, tetraethylene glycol dimethacrylate, tetrahydrofurfuryl (meth) acrylate.

5. The ultraviolet light cured flame retardant acrylic filling glue of claim 1, wherein the photoinitiator is selected from one or more of 1173, 184, BP, TMO, 819;

the auxiliary agent is one or more selected from silane coupling agent, leveling agent and defoaming agent.

6. The ultraviolet light-cured flame-retardant acrylic filling adhesive according to claim 1, wherein the organophosphorus-modified photocurable acrylate resin is prepared by the following method:

9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and glycidyl methacrylate were reacted in an amount of 1:1 are mixed in a three-neck flask according to the molar ratio, are subjected to constant-temperature water bath at 95 ℃, are subjected to condensation reflux, are mechanically stirred, react for 2 hours after 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is completely dissolved, and are taken out and cooled to obtain the organophosphorus modified photocuring acrylate resin.

7. The ultraviolet light-cured flame-retardant acrylic filling adhesive according to claim 1, wherein the organic phosphorus nitrogen modified photo-cured acrylate resin is prepared by the following method:

9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tris (2-hydroxyethyl) isocyanuric acid triacrylate were reacted in an amount of 1:1 are mixed in a three-neck flask according to the molar ratio, are subjected to constant-temperature water bath at 95 ℃, are subjected to condensation reflux, are mechanically stirred, react for 2 hours after 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is completely dissolved, and are taken out and cooled to obtain the organic phosphorus nitrogen modified photo-curing acrylate resin.

8. The ultraviolet light-cured flame-retardant acrylic filling adhesive according to claim 1, wherein the organophosphorus nitrogen sulfur modified photocuring acrylic resin is prepared by the following method:

9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and thiourea were reacted in an amount of 1:1, adding 70mL of pure water as a solvent into a three-neck flask, carrying out constant-temperature water bath at 95 ℃, condensing and refluxing, mechanically stirring, and reacting for 8 hours; after the reaction, pouring out the product, standing for 0.5h to obtain a turbid solution, washing with pure water twice, drying the obtained solid product at 110 ℃ for 10h, grinding the obtained white blocky product into powder, and mixing the product with a ratio of 1:2 is mixed in acrylic acid in a molar ratio to amidate, and water products are distilled off to obtain the organic phosphorus nitrogen sulfur modified photo-curing acrylate resin.

9. A method for preparing the ultraviolet light curing flame retardant acrylic filling glue according to any one of claims 1-8, comprising the following steps:

Under clean, low-humidity and light-resistant environment, 1-6 parts of flame-retardant modified photo-curing acrylate resin, 20-40 parts of acrylate resin, 40-70 parts of reactive diluent, 1-5 parts of photoinitiator and 0.1-3 parts of auxiliary agent are mixed according to parts by weight, and mechanically stirred for 15-60min at the rotating speed of 250-1000r/min to obtain the ultraviolet light-curing flame-retardant acrylic filling adhesive.

10. The photo-curing adhesive film is characterized by being prepared by the following steps: uniformly coating the ultraviolet light curing flame-retardant acrylic filling adhesive according to any one of claims 1-8 on a substrate, and curing by ultraviolet light to obtain the photo-curing adhesive film.