CN105713201A - Organosilicon bonding promoter for LED packaging high-refractive-index addition-type silica gel and preparation method and application of organosilicon bonding promoter - Google Patents

Abstract

The invention discloses an organic silicon adhesion promoter for LED packaging high refractive index addition type silica gel, a preparation method and an application thereof. The preparation method is to stir the organic silicon compound containing hydroxyl group and phenyl group, epoxy silane, ester silane and solvent evenly at room temperature, add a titanate catalyst, react at a temperature of 25-60° C. for 6-15 hours, and then The reaction is continued for 2-6 hours at a vacuum degree of 0.05-0.098MPa and a temperature of 60-140° C. to prepare a high-refractive-index organic silicon adhesion promoter containing epoxy groups and ester groups. The adhesion promoter prepared by the present invention has a high refractive index, good compatibility with high-refractive-index addition-type silica gel for LED packaging, and can significantly improve the adhesive performance of silica gel, especially for polyphthalamide and polyterephthalamide. The bonding properties of 1,4-cyclohexanedimethylformyl formate and plastic substrates such as polycarbonate can be widely used in the field of LED device packaging.

Description

Silicone adhesion promoter for LED packaging high refractive index addition type silica gel and its preparation method and application

technical field

The invention relates to the technical field of silicone packaging materials, in particular to a silicone adhesion promoter for LED packaging high refractive index addition type silica gel and a preparation method thereof. The silicone adhesion promoter is used for LED packaging high refractive index addition type. Molded in silicone.

Background technique

In order to improve the stability and reliability of LED devices, it is necessary to package and protect the devices from moisture, salt spray, dust, vibration and shock. When the addition-type encapsulation silica gel is cured, the amount of catalyst is less, no by-products are produced, it can be cured in deep layers, the linear shrinkage rate is low, and the electrical insulation performance is excellent. Especially the addition-type encapsulation silica gel with high refractive index can effectively improve the light extraction efficiency, which is high One of the performance packaging materials. However, most of the surface of the addition-type encapsulation silica gel is non-polar organic groups after curing, which has poor adhesion to the LED substrate. The encapsulated lamp beads are prone to dead lights during reflow soldering. It is easy to fall off from the LED base material or the bracket during impact, which seriously affects the service life of the LED device.

At present, the main method to improve the adhesive performance of addition-type packaging silicone is to add an adhesion promoter. US Patent No. 4,311,739 discloses that the addition of a partial hydrolyzate of alkoxysilane containing a C=C double bond can improve the bonding performance of addition-type silica gel to substrates such as glass, stainless steel, and copper. Chinese invention patent application CN103755963A reports a polysiloxane adhesion promoter containing acryloyloxy, epoxy and isocyanurate groups synthesized by hydrolysis and condensation. Adhesion properties of molded packaging silicone to aluminum and copper sheets. However, there are disadvantages such as difficult control of hydrolysis and condensation reaction, easy to produce gel, and easy ring opening of epoxy groups under strong acidic conditions.

In recent years, with the wide application of high-refractive-index addition-type packaging silica gel, the requirements for its adhesive performance are also getting higher and higher. However, the existing adhesion promoters have a large amount of addition, low refractive index, poor compatibility with high refractive index addition type packaging silica gel, and easily damage the curing performance, light transmittance and mechanical properties of silica gel.

Contents of the invention

The object of the present invention is to address the deficiencies of the prior art and provide a silicone adhesion promoter capable of significantly improving the adhesion performance of LED packaging high refractive index addition type silica gel and a preparation method thereof.

Another object of the present invention is to provide the application of the organic silicon adhesion promoter in high refractive index addition type silica gel for LED packaging.

The purpose of the present invention is achieved through the following technical solutions:

Preparation method of organic silicon adhesion promoter for high refractive index addition type silica gel for LED packaging: stir organic silicon compound containing hydroxyl and phenyl, epoxy silane, ester silane and solvent at room temperature, add the total mass of reactants 0.2% to 5% titanate catalyst, react at a temperature of 25 to 60°C for 6 to 15 hours, and then continue to react at a vacuum of 0.05 to 0.098MPa and a temperature of 60 to 140°C for 2 to 6 hours to obtain a ring-containing Oxygen- and ester-based high-refractive-index silicone adhesion promoters;

The general structural formula of the hydroxyl and phenyl organosilicon compound is:

Wherein, Me is methyl, Ph is phenyl, a is 0-10, b is 0-20, c is 0-10, b+c>0;

The molar ratio of the hydroxyl- and phenyl-containing organosilicon compound to the total amount of epoxy silane and ester silane is 0.8:1 to 2.5:1; the molar ratio of epoxy silane to ester silane is 0.3:1 ~5:1.

To further realize the object of the present invention, preferably, the epoxy silane is 3-(2,3-glycidoxy) propyltrimethoxysilane, 3-(2,3-glycidoxy) propyl Methyldimethoxysilane, 3‐(2,3‐glycidoxy)propyltriethoxysilane, 3‐(2,3‐glycidoxy)propylmethyldiethoxysilane, 2‐(3,4‐epoxycyclohexyl)ethyltrimethoxysilane, 2‐(3,4‐epoxycyclohexyl)ethylmethyldimethoxysilane, 2‐(3, One or more of 4-epoxycyclohexyl)ethyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane.

Preferably, the solvent is one or more of toluene, xylene, acetone, methanol, ethanol and isopropanol.

Preferably, the ester-based silane is 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxy One or more of propyltriethoxysilane and 3‐methacryloxypropylmethyldiethoxysilane.

Preferably, the titanate catalyst is tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate , one or more of tetraoctyl titanate, diisopropyl di(acetylacetonate) titanate and diisopropyl di(ethyl acetoacetate)titanium.

Preferably, the mass ratio of the hydroxyl- and phenyl-containing organosilicon compound to the solvent is 0.4:1˜2:1.

An organic silicon adhesion promoter for LED encapsulating high refractive index addition type silica gel, which is prepared by the above preparation method.

Application of the organic silicon adhesion promoter in high refractive index addition type silica gel for LED packaging. The application method is preferably 100 parts by mass of vinylphenyl silicone resin, 5-60 parts by mass of vinylphenyl silicone oil, 5-30 parts by mass of phenyl hydrogen-containing silicone oil, 0.8-6 parts by mass of adhesion promoter Mix well with 0.002-0.02 parts by mass of 1-ethynyl-1-cyclohexanol, then add 0.05-0.5 parts by mass of platinum catalyst, mix well, defoam, cure at 60-100°C for 1-2 hours, and then Continue curing at 130-150°C for 2-5 hours. The degassing time is preferably 5-30 minutes.

The organosilicon adhesion promoter of the invention is prepared by using titanate as a catalyst, which avoids the disadvantage that epoxy groups are easy to open rings when strong acid or strong base is used as a catalyst, and the reaction process is relatively easy to control. Silicone adhesion promoter contains both C=C double bonds and polar groups such as epoxy groups, ester groups, etc. The former can participate in the curing reaction of addition-type encapsulation silica gel, and the latter can form a stronger interaction with the substrate , thereby improving the adhesive performance of the addition-type LED packaging silicone. The adhesion promoter also contains phenyl chains to make it have a high refractive index, and has good compatibility with the high refractive index addition type silica gel for LED packaging.

Compared with the prior art, the present invention has the following advantages:

1. The organic silicon adhesion promoter prepared by the present invention can significantly improve the adhesion performance of high refractive index addition type silica gel for LED packaging, especially polyphthalamide (PPA), polyterephthalic acid 1,4 ‐ Adhesive properties of plastic substrates such as cyclohexanedimethanol ester (PCT) and polycarbonate (PC). Adding a small amount (generally less than 3 parts by mass) of silicone adhesion promoter to LED packaging silica gel can increase the adhesive strength of silica gel by more than 110%, especially for PPA, PCT and PC substrates. More than 240%.

2. The organic silicon adhesion promoter prepared by the present invention has a high refractive index, good compatibility with high-refractive-index addition-type silica gel for LED packaging, and has little influence on the light transmittance, mechanical properties, viscosity and other properties of the silica gel.

3. The preparation process of the present invention is simple and easy to control, has low requirements on production equipment, cheap and easy-to-obtain raw materials, and is easy to realize industrial production, and has good application prospects.

detailed description

In order to better understand the present invention, the present invention will be further described below in conjunction with the examples, but the embodiments of the present invention are not limited thereto.

Example 1

55.93g of phenylhydroxy silicone oil with molecular formula HO(MePhSiO) ₅ H, 11.82g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 12.42g of 3-methacryloxypropyltrimethoxy Add silane and 60g of toluene into a 250mL three-necked flask equipped with a thermometer, mechanical stirring and a condensing reflux tube, stir evenly at room temperature, add 1.6g of tetraisopropyl titanate, react at a temperature of 30°C for 8h, and then The reaction was continued for 5 hours at 0.08MPa and 80°C to obtain Adhesion Promoter 1 with a refractive index of 1.529.

100 parts by mass of vinyl phenyl silicone resin with a vinyl content of 4 wt%, 15 parts by mass of vinyl phenyl silicone oil with a viscosity of 500mPa·s, 30 parts by mass of phenyl hydrogen-containing silicone oil with an active hydrogen content of 0.45 wt%, 3 parts by mass of adhesion promoter 1 and 0.02 parts by mass of 1-ethynyl-1-cyclohexanol were mixed uniformly under the action of a high-speed mixer, and then 0.4 parts by mass of platinum-methylphenyl polysiloxane was added to compound Mix them evenly, defoam in a vacuum oven for 20 minutes, cure at 80°C for 1 hour, and then continue to cure at 150°C for 3 hours. The properties of the samples are shown in Table 1 and Table 2.

Example 2

61.29g of phenylhydroxy silicone oil with the molecular formula of HO(Ph ₂ SiO) ₃ H, 11.14g of 3-(2,3-epoxypropoxy)propyltriethoxysilane, 17.42g of 3-methacryloxypropyl Add triethoxysilane and 150g of xylene into a 500mL three-necked flask equipped with a thermometer, mechanical stirring and a condensing reflux tube, stir well at room temperature, add 0.45g of tetra-n-butyl titanate, and react at a temperature of 50°C for 6h , and then continue to react for 3 h at a vacuum of 0.06 MPa and a temperature of 110° C. to obtain adhesion promoter 2 with a refractive index of 1.532.

100 parts by mass of vinyl phenyl silicone resin with a vinyl content of 2 wt%, 6 parts by mass of vinyl phenyl silicone oil with a viscosity of 800mPa·s, 14 parts by mass of phenyl hydrogen-containing silicone oil with an active hydrogen content of 0.3 wt%, 2 parts by mass of adhesion promoter 2 and 0.01 parts by mass of 1-ethynyl-1-cyclohexanol were mixed uniformly under the action of a high-speed disperser, and then 0.2 parts by mass of platinum-methylphenyl polysiloxane was added Mix the complex evenly, defoam in a vacuum oven for 15 minutes, cure at 60°C for 2 hours, and then continue to cure at 130°C for 5 hours. The properties of the samples are shown in Table 1 and Table 2.

Example 3

143.92g of phenylhydroxy silicone oil with molecular formula HO(MePhSiO) ₄ (Ph ₂ SiO) ₂ H, 19.71g of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 4.97g of 3-methyl Add acryloyloxypropyltrimethoxysilane and 350g toluene into a 1000mL three-necked flask equipped with a thermometer, mechanical stirring and a condensing reflux tube, stir well at room temperature, add 1.69g tetraethyl titanate, After reacting for 15 hours, the reaction was continued for 2 hours at a vacuum degree of 0.05 MPa and a temperature of 140° C. to obtain adhesion promoter 3 with a refractive index of 1.538.

100 parts by mass of vinyl phenyl silicone resin with a vinyl content of 5 wt%, 30 parts by mass of vinyl phenyl silicone oil with a viscosity of 2000mPa·s, 25 parts by mass of phenyl hydrogen-containing silicone oil with an active hydrogen content of 0.6 wt%, 6 parts by mass of adhesion promoter 3 and 0.008 parts by mass of 1-ethynyl-1-cyclohexanol were mixed uniformly under the action of a high-speed disperser, and then 0.16 parts by mass of platinum-methylphenyl polysiloxane was added Mix the complex evenly, defoam in a vacuum oven for 30 minutes, cure at 70°C for 1 hour, and then continue to cure at 150°C for 3 hours. The properties of the samples are shown in Table 1 and Table 2.

Example 4

The difference between this example and Example 1 is that 3-(2,3-epoxypropoxy)propyltrimethoxysilane is changed to 2-(3,4-epoxycyclohexyl)ethyltriethyl Oxysilane, and its consumption is 14.42g, makes adhesion promoter 4, and its refractive index is 1.527.

The adhesion promoter 1 in Example 1 was changed to the adhesion promoter 4, and its dosage was 4 parts by mass. The properties of the samples are shown in Table 1 and Table 2.

Example 5

The difference between this example and example 2 is that the amount of the adhesion promoter 2 is changed to 3 parts by mass. The properties of the samples are shown in Table 1 and Table 2.

Comparative example 1

100 parts by mass of vinyl phenyl silicone resin with a vinyl content of 4wt%, 15 parts by mass of vinylphenyl silicone oil with a viscosity of 500mPa·s, 30 parts by mass of active hydrogen with a content of 0.45wt% phenyl hydrogen-containing silicone oil and 0.02 parts by mass of 1-ethynyl-1-cyclohexanol was mixed uniformly under the action of a high-speed disperser, and then 0.4 parts by mass of platinum-methylphenylpolysiloxane complex was added, mixed uniformly, and placed in a vacuum oven Degassing for 20 minutes, curing at 80°C for 1 hour, and then curing at 150°C for 3 hours. The properties of the samples are shown in Table 1 and Table 2.

Comparative example 2

100 parts by mass of vinyl phenyl silicone resin with a vinyl content of 2%wt, 6 parts by mass of vinylphenyl silicone oil with a viscosity of 800mPa·s, 14 parts by mass of phenyl hydrogen-containing silicone oil with an active hydrogen content of 0.3%wt Mix well with 0.01 mass parts of 1-ethynyl-1-cyclohexanol under the action of a high-speed disperser, then add 0.2 mass parts of platinum-methylphenylpolysiloxane complex, mix well, and place in a vacuum oven Degassing in medium for 15min, curing at 60°C for 2h, and then curing at 130°C for 5h. The properties of the samples are shown in Table 1 and Table 2.

Comparative example 3

100 parts by mass of vinyl phenyl silicone resin with a vinyl content of 5 wt%, 30 parts by mass of vinyl phenyl silicone oil with a viscosity of 2000mPa·s, 25 parts by mass of phenyl hydrogen-containing silicone oil with an active hydrogen content of 0.6 wt%, and 0.008 parts by mass of 1-ethynyl-1-cyclohexanol was mixed uniformly under the action of a high-speed disperser, and then 0.16 parts by mass of platinum-methylphenylpolysiloxane complex was added, mixed uniformly, and placed in a vacuum oven Degassing for 30min, curing at 70°C for 1h, and then curing at 150°C for 3h. The properties of the samples are shown in Table 1 and Table 2.

The performance test methods of the samples in Table 1 and Table 2 are as follows:

1. According to GB/T2794-1995, measure the viscosity of LED packaging addition type silica gel.

2. According to GB/T2410-2008, measure the light transmittance of LED packaging addition type silica gel.

3. According to GB/T614-2006, measure the refractive index of adhesion promoter and LED packaging addition type silica gel.

4. According to GB/T13936-1992, determine the bonding tensile shear strength of LED packaging addition type silica gel and substrate.

5. According to GB/T528‐2009, determine the tensile strength of LED encapsulation addition molding silica gel.

6. According to GB/T531.1-2008, determine the Shore D hardness of LED packaging addition molding silica gel.

Table 1

It can be seen from Table 1 that when no organic silicon adhesion promoter is added, the adhesive performance of LED packaging high refractive index addition type silica gel is poor, especially the adhesive strength to PPA, PCT and PC substrates is less than 0.63MPa ( See Comparative Examples 1-3). After adding the adhesion promoter synthesized by the present invention, the adhesive performance of LED packaging high refractive index addition type silica gel has been significantly improved, and its adhesive strength can be improved by more than 110%, especially for PPA, PCT and PC substrates. The bond strength was increased by more than 240% (see Examples 1-5). This is mainly because on the one hand, the adhesion promoter contains C=C double bonds that can react with the SiH bonds in silica gel, and on the other hand, the adhesion promoter contains polar groups such as epoxy groups and ester groups that can form bonds with the substrate. Strong interaction, so that the silica gel has better bonding performance. In addition, it can be seen from Table 2 that the addition of the adhesion promoter has little effect on the viscosity, refractive index, light transmittance and mechanical properties of the LED packaging high refractive index addition type silica gel.

Table 2

Claims (10)

1. The preparation method of silicone adhesion promoter for high refractive index addition type silica gel for LED packaging, characterized in that: the organosilicon compound containing hydroxyl and phenyl, epoxy silane, ester silane and solvent are stirred evenly at room temperature , add a titanate catalyst of 0.2% to 5% of the total mass of reactants, react at a temperature of 25 to 60°C for 6 to 15 hours, and then continue to react at a vacuum of 0.05 to 0.098MPa and a temperature of 60 to 140°C for 2 ~6h, to obtain a high refractive index silicone adhesion promoter containing epoxy groups and ester groups; The general structural formula of the hydroxyl and phenyl organosilicon compound is: Wherein, Me is methyl, Ph is phenyl, a is 0-10, b is 0-20, c is 0-10, b+c>0; The molar ratio of the hydroxyl- and phenyl-containing organosilicon compound to the total amount of epoxy silane and ester silane is 0.8:1 to 2.5:1; the molar ratio of epoxy silane to ester silane is 0.3:1 ~5:1. 2. A method for preparing a silicone adhesion promoter for high refractive index addition type silica gel in LED packaging, characterized in that the epoxy silane is 3‐(2,3‐glycidyloxy)propyltrimethoxysilane , 3‐(2,3‐glycidoxy)propylmethyldimethoxysilane, 3‐(2,3‐glycidoxy)propyltriethoxysilane, 3‐(2,3‐ Glycidoxy)propylmethyldiethoxysilane, 2‐(3,4‐epoxycyclohexyl)ethyltrimethoxysilane, 2‐(3,4‐epoxycyclohexyl) Ethylmethyldimethoxysilane, 2‐(3,4‐epoxycyclohexyl)ethyltriethoxysilane and 2‐(3,4‐epoxycyclohexyl)ethylmethyl One or more of diethoxysilanes. 3. The preparation method of organic silicon adhesion promoter for high refractive index addition type silica gel for LED packaging, characterized in that, the solvent is one or more of toluene, xylene, acetone, methanol, ethanol and isopropanol . 4. A method for preparing an organic silicon adhesion promoter for high refractive index addition type silica gel for LED packaging, characterized in that the ester silane is 3-methacryloxypropyltrimethoxysilane, 3-methyl One of acryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane and 3-methacryloxypropylmethyldiethoxysilane one or more species. 5. The preparation method of an organic silicon adhesion promoter for high refractive index addition type silica gel in LED packaging, characterized in that the titanate catalyst is tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate ester, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate, tetraoctyl titanate, bis(acetylacetonate)diisopropyl titanate and bis(ethyl acetoacetate)titanium di One or more of isopropyl esters. 6. A method for preparing an organic silicon adhesion promoter for high refractive index addition type silica gel for LED packaging, characterized in that the mass ratio of the organic silicon compound containing hydroxyl and phenyl to the solvent is 0.4:1-2:1. 7. The organic silicon adhesion promoter for high refractive index addition type silica gel for LED packaging, characterized in that it is prepared by the preparation method described in claim 1. 8. The application of the organic silicon adhesion promoter described in claim 7 in the high refractive index addition type silica gel for LED encapsulation. 9. The application of the organic silicon adhesion promoter according to claim 8 in high refractive index addition type silica gel for LED packaging, characterized in that 100 parts by mass of vinylphenyl silicone resin, 5-60 parts by mass of Vinyl phenyl silicone oil, 5-30 parts by mass of phenyl hydrogen-containing silicone oil, 0.8-6 parts by mass of adhesion promoter and 0.002-0.02 parts by mass of 1-ethynyl-1-cyclohexanol are mixed evenly, and then added 0.05-0.5 parts by mass of platinum-based catalysts are uniformly mixed, defoamed, cured at 60-100° C. for 1-2 hours, and then cured at 130-150° C. for 2-5 hours. 10 . The application of the organic silicon adhesion promoter according to claim 9 in high refractive index addition type silica gel for LED packaging, characterized in that the degassing time is 5-30 minutes. 11 .