High-transmittance and low-haze photocuring release agent

Abstract

The invention discloses a photocuring release agent with high light transmittance and low haze, and belongs to the technical field of release agents. The photocuring release agent with high light transmittance and low haze prepared by the invention is prepared from the following components in parts by mass: 40 to 60 parts of bio-based siloxane, 15 to 35 parts of polydimethylsiloxane with high vinyl content, 5 to 10 parts of fluorine-containing acrylic monomer, 1 to 3 parts of disulfide bond cross-linking agent, 3 to 6 parts of bimetallic MOF (Metal Organic Framework) catalyst and 0.1 to 0.5 part of hydroxylated boron nitride. The prepared light-cured release agent has the effects of high light transmittance and low haze and is high in peel strength, the bimetallic MOF catalyst is low in price and easy to obtain, and the preparation cost is greatly reduced. Polydimethylsiloxane with high vinyl content is used as a main chain and is matched with a fluorine-containing acrylic monomer, and a bicontinuous network of a hydrophobic fluorine chain segment and a flexible siloxane chain is formed through photopolymerization induced microphase separation, so that the light transmittance of the release agent is effectively improved, and the haze is reduced; therefore, the film has a wider application prospect in the fields of release films for optical display and the like with high requirements on light transmission performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of release agents, and particularly relates to a photocurable release agent with high light transmittance and low haze. Background Art

[0002] Release films have now been widely used in industries such as packaging, printing, flexible circuits, laser anti-counterfeiting, reflective materials, waterproof materials, adhesive products, die-cutting and stamping processing, etc. Release films for optical displays are used as components for various displays such as polarizers and organic ELs for flat panel displays due to their excellent properties. Existing release film products for optical displays generally have the disadvantages of high haze values and low light transmittance. Based on silicone release films, introducing fluorine elements can, to a certain extent, reduce the surface tension of the release coating, produce excellent peeling performance, increase the light transmittance of the release film, and reduce haze, thus being applied to components for various displays such as polarizers, polarizer protective films, and organic ELs for flat panel displays.

[0003] However, generally, noble metal catalysts (such as iridium, platinum, ruthenium, etc.) are used. The use of noble metals significantly increases the production cost, and the high temperature and high energy consumption required for heat curing are not suitable for some substrates. Photocuring takes a long time and has a low curing degree. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a photocurable release agent with high light transmittance and low haze. The photocurable release agent prepared by the present invention has the effects of high light transmittance, low haze, relatively high peeling strength, and the bimetallic MOF catalyst is cheap and easily available, greatly reducing the preparation cost.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] In the first aspect, the present invention provides a photocurable release agent with high light transmittance and low haze, comprising the following components in parts by mass:

[0007] 40 - 60 parts of bio-based siloxane, 15 - 35 parts of polydimethylsiloxane with high vinyl content, 5 - 10 parts of fluorinated acrylic monomer, 1 - 3 parts of disulfide crosslinking agent, 3 - 6 parts of bimetallic MOF catalyst, 0.1 - 0.5 part of hydroxylated boron nitride.

[0008] The present invention uses polydimethylsiloxane with high vinyl content as the main chain, and is combined with a fluorinated acrylic monomer. Through photoinduced phase separation, a bicontinuous network of hydrophobic fluorine segments and flexible siloxane chains is formed, reducing the light scattering path.

[0009] Preferably, the preparation method of the bio-based siloxane is: reacting methyl epoxy ricinoleate, methyltrichlorosilane, and tetramethylammonium hydroxide under alkaline conditions at 80 - 100 °C for 6 h to obtain bio-based siloxane.

[0010] Preferably, the epoxy value of the biobased siloxane is 0.45 to 0.65 eq / kg, and the viscosity is 5000 to 6000 mPa·s.

[0011] Preferably, the molar ratio of the methyl ricinoleate epoxide, methyltrichlorosilane, and tetramethylammonium hydroxide is 10:(1 - 3):0.1.

[0012] Preferably, the vinyl content of the high vinyl content polydimethylsiloxane is 5 to 10%, and the viscosity is 8000 to 10000 mPa·s.

[0013] Preferably, the fluorinated acrylic monomer includes one of perfluorooctyl acrylate, perfluorobutyl acrylate, fluoroacrylamide, pentadecafluorooctanoic acid, and heptadecafluorononanoic acid.

[0014] Preferably, the preparation method of the bimetallic MOF catalyst is as follows: Dissolve zinc nitrate, iron nitrate, 4-pyridinecarboxylic acid, and benzimidazole derivative in DMF, and generate porous MOF particles through hydrothermal reaction, followed by centrifugal washing and drying;

[0015] Mix the MOF catalyst, TPO, diphenylacetone alcohol, and 10-methyl-9-mesityl acridine perchlorate by ball milling.

[0016] Preferably, the molar ratio of zinc nitrate, iron nitrate, 4-pyridinecarboxylic acid, and benzimidazole derivative is 1:1:1.

[0017] Preferably, the hydrothermal reaction temperature is 100 to 120 °C, and the reaction time is 12 to 24 h.

[0018] Preferably, the specific surface area of the bimetallic MOF catalyst is ≥1200 m 2 / g, and the particle size is 50 - 100 nm.

[0019] Preferably, the mass ratio of the MOF catalyst, TPO, diphenylacetone alcohol, and 10-methyl-9-mesityl acridine perchlorate is 1:2:1:0.5.

[0020] The present invention takes zinc-iron bimetal as the center and 4-pyridinecarboxylic acid and benzimidazole derivative as the ligands to form a porous MOF structure, enhancing light absorption and exposure of active sites, and replacing traditional noble metal catalysts. Preferably, the preparation method of the hydroxylated boron nitride is as follows: Immerse spherical boron nitride in 5% hydrofluoric acid for 30 min, wash it with water to neutrality after etching, and then reflux it with silane coupling agent KH-550 in ethanol to obtain surface hydroxylated boron nitride. Through the above scheme, the interfacial compatibility can be improved, and at the same time, light scattering can be reduced.

[0021] Preferably, the particle size of the spherical boron nitride is 10-50 nm.

[0022] Preferably, the dosage of the silane coupling agent KH-550 is 1% of the mass of the spherical boron nitride.

[0023] Preferably, the reflux reaction temperature is 80 °C and the time is 4 h.

[0024] It has at least the following beneficial technical effects:

[0025] The photocurable release agent prepared by the present invention has the effects of high light transmittance and low haze, relatively high peel strength, and the bimetallic MOF catalyst is cheap and easily available, greatly reducing the preparation cost. At the same time, the MOF structure has a high specific surface area, a particle size of 50-100 nm, which can enhance light absorption and exposure of active sites, and has excellent catalytic performance, which can improve the efficiency and degree of the photocuring reaction, and solve the problems of long traditional photocuring time and low curing degree. Based on poly(dimethylsiloxane) with a high vinyl content as the main chain, combined with fluorinated acrylic monomers, a double-continuous network of hydrophobic fluorine segments and flexible silicone chains is formed through photoinduced microphase separation. This unique structure can reduce the light scattering path, effectively improve the light transmittance of the release agent and reduce the haze, making it have a wider application prospect in fields with high requirements for light transmittance performance such as release films for optical displays. Hydroxylated boron nitride is prepared by a specific method, obtained by etching spherical boron nitride in hydrofluoric acid and then reacting with the silane coupling agent KH-550. It can improve the interfacial compatibility, make it better dispersed in the release agent system, and at the same time reduce light scattering, further optimizing the optical properties of the release agent. Detailed Description of the Invention

[0026] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0027] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not used to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded within the range.

[0028] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of this invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0029] Without departing from the scope or spirit of this invention, various modifications and variations can be made to the specific embodiments of the specification of this invention, which are obvious to those skilled in the art. Other embodiments obtained from the specification of this invention are obvious to those skilled in the art. The specification and examples of this application are merely exemplary.

[0030] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0031] As used in this invention, "room temperature" and "normal temperature" are both calculated as 25 ± 2 °C unless otherwise specified.

[0032] Unless otherwise specified, the raw materials or instruments used in the following examples of this invention are all obtained commercially.

[0033] Preparation of bio-based siloxane:

[0034] Weigh methyl ricinoleate, methyltrichlorosilane, and tetramethylammonium hydroxide according to a molar ratio of 10:2:0.1, and react them under alkaline conditions at 90 °C for 6 h to obtain bio-based siloxane.

[0035] The epoxy value of the said bio-based siloxane is 0.55 eq / kg, and the viscosity is 5320 mPa·s.

[0036] Preparation of bimetallic MOF catalyst:

[0037] Weigh zinc nitrate, iron nitrate, 4-pyridinecarboxylic acid, and benzimidazole derivative according to a molar ratio of 1:1:1, dissolve them in DMF, and carry out hydrothermal reaction at 110 °C for 16 h to generate porous MOF particles, which are dried after centrifugation and washing;

[0038] Weigh the MOF catalyst, TPO, diphenylacetone alcohol, and 10-methyl-9-mesityl acridine perchlorate according to a mass ratio of 1:2:1:0.5 and mix them by ball milling.

[0039] The specific surface area of the said bimetallic MOF catalyst ≥ 1200 m 2 / g, and the particle size is 80 nm.

[0040] Preparation of hydroxylated boron nitride:

[0041] The spherical boron nitride with a particle size of 30 nm was immersed in 5% hydrofluoric acid for 30 min, washed with water to neutrality after etching, and then refluxed with 1 wt% silane coupling agent KH-550 in ethanol at 80 °C for 4 h to obtain surface-hydroxylated boron nitride. Through the above scheme, the interfacial compatibility can be improved, and at the same time, light scattering can be reduced.

[0042] Example 1

[0043] This example provides a photocurable release agent with high light transmittance and low haze, which comprises the following components in parts by mass:

[0044] 50 parts of bio-based silicone, 20 parts of polydimethylsiloxane with high vinyl content, 8 parts of perfluorooctyl acrylate, 2 parts of disulfide crosslinking agent, 4 parts of bimetallic MOF catalyst, 0.3 part of hydroxylated boron nitride.

[0045] The vinyl content of the polydimethylsiloxane with high vinyl content is 6%, and the viscosity is 8250 mPa·s.

[0046] The components were mixed evenly to obtain a photocurable release agent with high light transmittance and low haze.

[0047] Example 2

[0048] This example provides a photocurable release agent with high light transmittance and low haze, which comprises the following components in parts by mass:

[0049] 40 parts of bio-based silicone, 15 parts of polydimethylsiloxane with high vinyl content, 5 parts of perpentadecafluorooctanoic acid, 1 part of disulfide crosslinking agent, 3 parts of bimetallic MOF catalyst, 0.1 part of hydroxylated boron nitride.

[0050] The vinyl content of the polydimethylsiloxane with high vinyl content is 5%, and the viscosity is 8000 mPa·s.

[0051] The components were mixed evenly to obtain a photocurable release agent with high light transmittance and low haze.

[0052] Example 3

[0053] This example provides a photocurable release agent with high light transmittance and low haze, which comprises the following components in parts by mass:

[0054] 60 parts of bio-based silicone, 35 parts of polydimethylsiloxane with high vinyl content, 10 parts of heptadecafluorononanoic acid, 3 parts of disulfide crosslinking agent, 6 parts of bimetallic MOF catalyst, 0.5 part of hydroxylated boron nitride.

[0055] The vinyl content of the polydimethylsiloxane with high vinyl content is 10%, and the viscosity is 10000 mPa·s.

[0056] Mix each component evenly to obtain a photocurable release agent with high light transmittance and low haze.

[0057] Comparative Example 1

[0058] This comparative example is the same as Example 1, except that the catalyst is a platinum catalyst.

[0059] Comparative Example 2

[0060] This comparative example is the same as Example 1, except that hydroxylated boron nitride is not added.

[0061] Experimental Example

[0062] The measurement standards for light transmittance and haze are GB / T 2410-2008, and the measurement standard for peel strength is GB / T 25256-2010; the release agents of Examples 1-3 were tested, as shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A light-curing release agent with high light transmittance and low haze, characterized in that: The composition comprises the following components in parts by weight: 40-60 parts of bio-based siloxane, 15-35 parts of high vinyl content polydimethylsiloxane, 5-10 parts of fluorine-containing acrylic monomer, 1-3 parts of disulfide bond crosslinking agent, 3-6 parts of bimetallic MOF catalyst, and 0.1-0.5 parts of hydroxylated boron nitride.

2. The light-curing release agent according to claim 1, characterized in that: The preparation method of the bio-based siloxane is as follows: methyl epoxyricinoleate, methyltrichlorosilane and tetramethylammonium hydroxide are reacted under alkaline conditions at 80-100° C. for 6 hours to obtain the bio-based siloxane.

3. The light-curing release agent according to claim 2, characterized in that: The epoxy value of the bio-based siloxane is 0.45 to 0.65 eq / kg, and the viscosity is 5000 to 6000 mPa·s.

4. The light-curing release agent according to claim 2, characterized in that: The molar ratio of epoxy ricinoleic acid methyl ester, methyltrichlorosilane and tetramethylammonium hydroxide is 10:(1-3):0.

1.

5. The light-curing release agent according to claim 1, characterized in that: The high vinyl content polydimethylsiloxane has a vinyl content of 5 to 10% and a viscosity of 8000 to 10000 mPa·s.

6. The light-curing release agent according to claim 1, characterized in that: The preparation method of the bimetallic MOF catalyst is as follows: zinc nitrate, ferric nitrate, 4-pyridinecarboxylic acid and a benzimidazole derivative are dissolved in DMF, and a porous MOF particle is generated by a hydrothermal reaction, and then dried after centrifugal washing; The MOF catalyst, TPO, diphenylacetophenone alcohol and 10-methyl-9-mesityl acridine perchlorate were mixed and ball-milled.

7. The light-curing release agent according to claim 6, characterized in that: The molar ratio of the zinc nitrate, the ferric nitrate, the 4-pyridinecarboxylic acid and the benzimidazole derivative is 1:1:

1.

8. The light-curing release agent according to claim 6, characterized in that: The specific surface area of ​​the bimetallic MOF catalyst is ≥1200m 2 / g, particle size is 50-100nm.

9. The light-curing release agent according to claim 6, characterized in that: The mass ratio of the MOF catalyst, TPO, diphenyl acetone alcohol, and 10-methyl-9-mesityl acridine perchlorate is 1:2:1:0.

5.

10. The light-curing release agent according to claim 1, characterized in that: The preparation method of the hydroxylated boron nitride is as follows: immersing the spherical boron nitride in 5% hydrofluoric acid for 30 minutes, washing with water to neutrality after etching, and then reflux reacting with silane coupling agent KH-550 in ethanol to obtain surface hydroxylated boron nitride.

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