Electronic paper edge sealing adhesive capable of being cured by UV moisture and preparation method of electronic paper edge sealing adhesive

Abstract

The invention provides an electronic paper edge sealing adhesive capable of being cured by UV moisture and a preparation method of the electronic paper edge sealing adhesive, and belongs to the technical field of electronic paper edge sealing adhesives. The invention relates to an electronic paper edge sealing adhesive capable of being cured by UV moisture. The electronic paper edge sealing adhesive is prepared from the following raw materials in parts by weight: 40 to 60 parts of isocyanate acrylate prepolymer, 20 to 40 parts of acrylic monomer, 3 to 6 parts of photoinitiator, 10 to 25 parts of filler and 1 to 5 parts of white pigment. The embodiment detailedly describes the preparation method and composition of the electronic paper edge sealing adhesive capable of being cured by UV moisture, and by optimizing the formula and the preparation process, the prepared edge sealing adhesive has the advantages of rapid curing, excellent bonding strength and mechanical property, good flexibility and weather resistance and high-quality processing control; the performance and the service life of an electronic paper product can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic edge sealing adhesives, and more particularly to an electronic paper edge sealing adhesive that can be cured by UV moisture and a preparation method thereof. Background Art

[0002] Electronic paper, also known as electronic ink screen, can be widely used in large shopping malls and supermarkets, warehouse storage shelves, chain stores, unmanned stores, hospital wards, conference venues and exhibition hall labels, etc.

[0003] With the increasing popularity of electronic paper, the market's quality requirements for electronic paper are also increasing. The factors that determine the quality of electronic paper are the quality of the substrates of each part and the stability of the frame sealant. The various substrates on the market are basically universal and there is no big difference. The key factor is to ensure that the crystal solution in the display works stably and cannot leak. Therefore, the quality of the frame sealant used in electronic paper is particularly important. The thickness of electronic paper is getting thinner and thinner, and the slight leakage of the frame sealant will seriously affect the display of electronic paper. Electronic paper can be folded or bent, which has higher requirements for the viscosity strength of the edge sealant. The popularity of electronic paper is getting higher and higher, and the crystal solution must be sealed and stable in various climate environments. Leakage. These factors determine that electronic paper needs a frame sealant with good adhesion, weather resistance, stability and construction convenience.

[0004] There is an urgent need to develop a UV moisture-curable adhesive for electronic paper edge sealing, which can achieve rapid UV light curing, assist in subsequent moisture curing, increase the cross-linking density of the colloid, and thus improve the water vapor barrier ability of the adhesive after it is fully cured, thereby extending the service life of the electronic paper. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a UV moisture-curable electronic paper edge sealing adhesive and a preparation method thereof, which can achieve rapid curing by ultraviolet radiation, is highly efficient and environmentally friendly, has a long process window time, and is easy to operate; and can also perform moisture curing in the later stage to increase the cross-linking density of the colloid, thereby improving the water vapor barrier ability of the adhesive after it is fully cured, thereby extending the service life of the electronic paper.

[0006] To achieve the above object, the present invention provides the following technical solutions, which mainly include: A UV moisture-curable electronic paper edge-sealing adhesive comprises the following raw materials in parts by weight: 40-60 parts of isocyanate acrylate prepolymer, 20-40 parts of acrylic acid monomer, 3-6 parts of photoinitiator, 10-25 parts of filler and 1-5 parts of white pigment.

[0007] In a specific embodiment, the acrylic monomer is a combination of one or more of isobornyl acrylate, isooctyl acrylate, tetrahydrofuran acrylate, lauryl acrylate, acryloylmorpholine, 2-phenoxyethyl acrylate, cyclotrimethylolpropane methylal acrylate, trimethylolpropane trimethacrylate, and dicyclopentenyl ethoxy methacrylate.

[0008] In a specific embodiment, the photoinitiator is a combination of one or more of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone.

[0009] In a specific embodiment, the filler is a combination of one or more of talc, calcium carbonate, and glass microspheres.

[0010] In a specific embodiment, the isocyanate acrylate prepolymer is made of 80-100 parts of isocyanate, 40-50 parts of isobornyl methacrylate, 30-40 parts of hydroxyethyl methacrylate, 30-40 parts of polyether polyol, 0.4-0.6 parts of catalyst, and 0.2-0.4 parts of inhibitor.

[0011] In a specific embodiment, isocyanate refers to a class of organic compounds containing -N=C=O functional groups, including but not limited to HDI, MDI, HMDI, XDI, IPDI trimer; Polyether polyol: a combination of one or more of polyoxypropylene diol, polyoxypropylene triol and polytetramethylene glycol; Catalyst: a combination of one or more of dioctyltin dilaurate, dibutyltin dilaurate, stannous octoate, dibutyltin oxide, and dibutyltin diacetate; Inhibitor: a combination of one or more of p-hydroxyanisole, hydroquinone, p-benzoquinone and 2-tert-butylhydroquinone.

[0012] In a specific embodiment, the isocyanate acrylate prepolymer is prepared by polymerization of hexamethylene diisocyanate trimer and polytetramethylene glycol, the catalyst is dibutyltin dilaurate, and the inhibitor is p-hydroxyanisole.

[0013] A method for preparing an electronic paper edge sealing adhesive comprises the following steps: a. Prepare an isocyanate acrylate prepolymer, sequentially add 40-50 parts of isobornyl methacrylate, 80-100 parts of isocyanate and 0.4-0.6 parts of a catalyst, under a nitrogen atmosphere, control the temperature at 60-70 ° C, add dropwise 30-40 parts of a polyether polyol while stirring, and react for 2H after the addition is completed; Add 30-40 parts of hydroxyethyl methacrylate and continue the reaction for 2 hours; stop heating, add 0.2-0.4 parts of polymerization inhibitor under stirring to obtain a self-made isocyanate acrylate prepolymer; b. Add homemade isocyanate acrylate and acrylic monomer, mix and stir for 10 minutes, vacuum degree -0.08MPa, control temperature at 25-30℃; c. Add photoinitiator, mix and stir for 15 minutes, vacuum degree -0.08MPa, and control the temperature at 25-30℃; d. Add filler and white pigment, stir for 15 minutes, vacuum degree -0.08MPa, and control the temperature at 25-30℃; e. The mixture obtained in step d) is packaged and degassed to obtain UV moisture-curable electronic paper edge sealing adhesive.

[0014] It can be seen from the above technical solution that, compared with the prior art, the electronic paper edge sealing adhesive prepared according to the above technical solution has the following advantages: 1. Fast and efficient curing performance. This application is a UV curing system. The edge sealant uses a photoinitiator (3-6 parts), such as 1-hydroxycyclohexyl phenyl ketone, which can quickly generate free radicals under ultraviolet light to start the polymerization reaction of acrylate and achieve rapid curing. In addition to UV curing, the edge sealant also has moisture curing ability and can continue to cure under insufficient UV irradiation or subsequent environmental conditions to ensure the complete curing and stability of the edge sealant.

[0015] 2. Excellent bonding strength and mechanical properties, isocyanate acrylate prepolymer (40-60 parts): generated by the reaction of various isocyanates such as HDI and MDI with polyether polyols to form a high molecular weight prepolymer, providing excellent bonding strength and mechanical properties; acrylic monomer (20-40 parts): such as isobornyl acrylate, lauryl acrylate, etc., to increase the cross-linking density of the polymer chain and enhance the overall mechanical strength and durability; A strong chemical bond is formed between the prepolymer and the substrate, ensuring that the edge banding adhesive is not easy to debond or peel off during use.

[0016] High mechanical strength and wear resistance enable the edge sealing adhesive to remain stable under stress such as bending and stretching, extending the service life of electronic paper products.

[0017] 3. Good flexibility and weather resistance, the combination of various acrylic monomers: such as tetrahydrofuran acrylate, dicyclopentenyl ethoxy methacrylate, etc., give the edge sealing adhesive good flexibility and weather resistance; The addition of fillers such as talcum powder, calcium carbonate, and glass beads not only improves the mechanical strength, but also maintains the flexibility of the edge banding adhesive to prevent brittle cracking.

[0018] 4. Optimized processing technology and production control, precise ratio and step control: by strictly controlling the weight of each component and the order of addition, the uniformity and stability of the prepolymer and the final edge sealant are ensured.

[0019] Vacuum degassing process: Vacuum (-0.08MPa) is used during the mixing process to remove bubbles and improve the sealing and surface quality of the edge sealing adhesive. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Embodiment 1 The electronic paper edge sealing adhesive in the present invention needs to use a self-made isocyanate acrylate prepolymer, and the raw material components of the self-made isocyanate acrylate prepolymer are as follows: Isocyanates (HDI, MDI, HMDI, XDI, IPDI trimer) Isobornyl Methacrylate Hydroxyethyl Methacrylate Polyether polyol: a combination of one or more of polyoxypropylene diol, polyoxypropylene triol and polytetramethylene glycol; Catalyst: a combination of one or more of dioctyltin dilaurate, dibutyltin dilaurate, stannous octoate, dibutyltin oxide, and dibutyltin diacetate; Inhibitor: a combination of one or more of p-hydroxyanisole, hydroquinone, p-benzoquinone, and 2-tert-butylhydroquinone; Preparation method of homemade isocyanate acrylate prepolymer: a. Sequentially add 40-50 parts of isobornyl methacrylate, 80-100 parts of isocyanate and 0.4-0.6 parts of catalyst, under a nitrogen atmosphere, control the temperature at 60-70 ° C, add dropwise 30-40 parts of polyether polyol while stirring, and react for 2H after the addition is completed; b. Add 30-40 parts of hydroxyethyl methacrylate and continue the reaction for 2 hours. Stop heating and add 0.2-0.4 parts of polymerization inhibitor under stirring. The self-made isocyanate acrylate prepolymer is obtained.

[0022] In a specific implementation, the homemade isocyanate acrylate prepolymer composition is as follows: Isocyanate: hexamethylene diisocyanate trimer (80 parts); Isobornyl methacrylate (45 parts); Hydroxyethyl methacrylate (30 parts); Polyether polyol: polytetramethylene glycol (30 parts); Catalyst: dibutyltin dilaurate (0.5 parts); Inhibitor: p-hydroxyanisole (0.2 parts); The self-made isocyanate acrylate prepolymer was prepared by polymerization of hexamethylene diisocyanate trimer and polytetramethylene glycol.

[0023] In Examples 1, 2 and 3, the self-made isocyanate acrylate prepolymers mentioned are all prepared by the above-mentioned method and raw material ratio.

[0024] A UV moisture-curable electronic paper edge-sealing adhesive, the raw materials of which are proportioned by weight as follows: Homemade isocyanate acrylate prepolymer 60 parts Acrylic acid monomer Isobornyl acrylate 15 parts Acrylic acid monomer tetrahydrofuran acrylate 15 parts Photoinitiator 1-hydroxycyclohexyl phenyl ketone 2 parts Photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide 1 part Filler talcum powder 15 parts White pigment titanium dioxide 1 part Follow these steps to prepare UV moisture-curable electronic paper edge sealant: Step a: Mixing prepolymer and acrylic monomer In a clean mixing container, add the homemade isocyanate acrylate prepolymer (60 parts) and isobornyl acrylate (15 parts) and tetrahydrofuran acrylate (15 parts).

[0025] The mixture was stirred for 10 minutes to ensure that the components were evenly dispersed.

[0026] Perform vacuum treatment to reach a vacuum degree of -0.08MPa to remove bubbles during the mixing process.

[0027] Control the mixing temperature at 25-30℃.

[0028] Step b: Adding photoinitiator Photoinitiators (1-hydroxycyclohexylphenyl ketone, 2 parts, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 1 part) were added to the mixture.

[0029] Continue mixing for 15 minutes to ensure that the photoinitiator is evenly dispersed.

[0030] The vacuum treatment was performed again to reach a vacuum degree of -0.08MPa.

[0031] The mixing temperature was controlled to be maintained at 30°C.

[0032] Step c: Add filler and white pigment Filler (talc, 15 parts) and white pigment (titanium dioxide, 1 part) were added to the mixture.

[0033] Stirring was carried out for 15 minutes to ensure that the filler and white pigment were evenly dispersed in the mixture.

[0034] Perform vacuum treatment to reach a vacuum degree of -0.08MPa.

[0035] The mixing temperature was controlled to be maintained at 30°C.

[0036] Step d: Packaging and degassing The mixture obtained above was divided into portions and placed in sealed containers.

[0037] Vacuum degassing equipment is used to further remove bubbles in the mixture to ensure the sealing and surface quality of the edge sealing adhesive.

[0038] Finally, the UV moisture-curable electronic paper edge sealing adhesive is obtained.

[0039] Embodiment 2 The homemade isocyanate acrylate prepolymer is as shown in Example 1, except that: Homemade isocyanate acrylate prepolymer 50 parts Acrylic acid monomer dicyclopentenyl ethoxy methacrylate 15 parts Acrylic acid monomer cyclotrimethylolpropane formal acrylate 5 parts Acrylic acid monomer lauryl acrylate 15 parts Photoinitiator 1-hydroxycyclohexyl phenyl ketone 2 parts Photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone 1 part Filler calcium carbonate 15 parts White pigment titanium dioxide 1 part Embodiment 3

[0040] The homemade isocyanate acrylate prepolymer is as shown in Example 1, except that: Homemade isocyanate acrylate prepolymer 50 parts Acrylic acid monomer dicyclopentenyl ethoxy methacrylate 15 parts Acrylic acid monomer Isobornyl acrylate 10 parts Acrylic acid monomer acryloyl morpholine 10 parts Photoinitiator 1-hydroxycyclohexyl phenyl ketone 2 parts Photoinitiator 2,2-dimethoxy-2-phenylacetophenone 1 part Filler talcum powder 15 parts White pigment titanium dioxide 1 part Comparative Example 1 60 parts of difunctional polyurethane acrylate oligomer Acrylic acid monomer Isobornyl acrylate 15 parts Acrylic acid monomer tetrahydrofuran acrylate 15 parts Photoinitiator 1-hydroxycyclohexyl phenyl ketone 2 parts Photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide 1 part Filler talcum powder 15 parts White pigment titanium dioxide 1 part The following are the test results of the products in the above examples and comparative examples. The curing conditions used were: UV curing energy 2000 mj / cm2, 25°C / 50%RH curing for 24 hours.

[0041] Example 1 Example 2 Example 3 Comparative Example 1 Shear strength (PC / PC) / MPa (UV curing) 3.6 3.2 3.8 3.5 Shear strength (PC / PC) / MPa (UV+moisture curing) 4.5 4.0 5.2 3.6 <![CDATA[Water vapor transmission rate at 60 °C, 90% RH (g / m 2 .24H)]]> 40 34 26 60 From the analysis of the test results, it can be seen that the UV moisture-curable electronic paper edge sealing adhesive of the present invention has good water vapor barrier ability and strong bonding strength.

[0042] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0043] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A UV moisture-curable electronic paper edge-sealing adhesive, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of isocyanate acrylate prepolymer, 20-40 parts of acrylic monomer, 3-6 parts of photoinitiator, 10-25 parts of filler and 1-5 parts of white pigment.

2. The electronic paper edge sealing adhesive according to claim 1, characterized in that: in, The acrylic monomer is a combination of one or more of isobornyl acrylate, isooctyl acrylate, tetrahydrofuran acrylate, lauryl acrylate, acryloylmorpholine, 2-phenoxyethyl acrylate, cyclotrimethylolpropane formal acrylate, trimethylolpropane trimethacrylate, and dicyclopentenyl ethoxy methacrylate.

3. The electronic paper edge sealing adhesive according to claim 1, characterized in that: in, The photoinitiator is a combination of one or more of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone.

4. The electronic paper edge sealing adhesive according to claim 1, characterized in that: in, The filler is a combination of one or more of talc, calcium carbonate and glass microspheres.

5. The electronic paper edge sealing adhesive according to any one of claims 1 to 4, characterized in that: The isocyanate acrylate prepolymer is prepared from 80-100 parts of isocyanate, 40-50 parts of isobornyl methacrylate, 30-40 parts of hydroxyethyl methacrylate, 30-40 parts of polyether polyol, 0.4-0.6 parts of catalyst and 0.2-0.4 parts of inhibitor.

6. The electronic paper edge sealing adhesive according to claim 5, characterized in that: in: Isocyanates include but are not limited to HDI, MDI, HMDI, XDI, and IPDI trimer; The polyether polyol is a combination of one or more of polyoxypropylene diol, polyoxypropylene triol and polytetramethylene glycol; The catalyst is a combination of one or more of dioctyltin dilaurate, dibutyltin dilaurate, stannous octoate, dibutyltin oxide, and dibutyltin diacetate; The polymerization inhibitor is a combination of one or more of p-hydroxyanisole, hydroquinone, p-benzoquinone and 2-tert-butylhydroquinone.

7. The electronic paper edge sealing adhesive according to claim 6, characterized in that: The isocyanate is hexamethylene diisocyanate trimer, the polyether polyol is polytetramethylene glycol, the catalyst is dibutyltin dilaurate, and the inhibitor is p-hydroxyanisole.

8. A method for preparing the electronic paper edge sealing adhesive according to claim 6 or 7, characterized in that: The method comprises the following steps: a. preparing an isocyanate acrylate prepolymer, sequentially adding 40-50 parts of isobornyl methacrylate, 80-100 parts of isocyanate and 0.4-0.6 parts of a catalyst, controlling the temperature at 60-70° C. under a nitrogen atmosphere, dripping 30-40 parts of a polyether polyol while stirring, and reacting for 2 hours after the dripping is completed; Add 30-40 parts of hydroxyethyl methacrylate and continue the reaction for 2 hours; stop heating, add 0.2-0.4 parts of polymerization inhibitor under stirring to obtain a self-made isocyanate acrylate prepolymer; b. Add homemade isocyanate acrylate and acrylic monomer, mix and stir for 10 minutes, vacuum degree -0.08MPa, control temperature at 25-30℃; c. Add photoinitiator, mix and stir for 15 minutes, vacuum degree -0.08MPa, and control the temperature at 25-30℃; d. Add filler and white pigment, stir for 15 minutes, vacuum degree -0.08MPa, and control the temperature at 25-30℃; e. The mixture obtained in step d) is packaged and degassed to obtain UV moisture-curable electronic paper edge sealing adhesive.