Volcano type polysiloxane packaging glue as well as preparation method and application thereof

Abstract

The invention relates to volcanic polysiloxane packaging glue as well as a preparation method and application thereof. The volcanic polysiloxane packaging glue is prepared from the following raw materials: non-reactive long-chain polysiloxane and a hydrophobic filler. The volcanic polysiloxane packaging glue disclosed by the invention has the use characteristics and various optical and mechanical indexes of a traditional packaging glue process, the appearance and shape of a volcanic lens can be uniform and stable after a starting point is glued, the light emitting angle can be greatly improved, the chip spacing can be increased, the chip use amount can be reduced, the cost is further reduced, and heat production is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, and in particular to a volcanic polysiloxane encapsulation glue and a preparation method and application thereof. Background Art

[0002] At present, the shape of the Mini-LED backlight packaging glue on the market is mostly convex lens after dispensing. However, due to the shape of the convex lens, the light output angle is certain, which means that the chip spacing cannot be too large, which in turn leads to a large number of chips used and high heat generation.

[0003] CN117143559A discloses a Mini LED polysiloxane encapsulation glue with uniform formability and high adhesion, as well as a preparation method and application thereof. A functional additive containing both a polyether segment and a polar group is introduced into the Mini LED polysiloxane encapsulation glue, so that the prepared Mini LED polysiloxane encapsulation glue has excellent bonding strength to a Mini LED substrate coated with ink, high reliability, uniform formability after curing, and high light output efficiency. However, the shape after dispensing is a convex lens, and the light output angle is certain; CN107502279A discloses a high-temperature resistant thixotropic LED encapsulation glue and a preparation method thereof. The light transmittance of the obtained high-temperature resistant thixotropic LED encapsulation glue is not high.

[0004] Therefore, it is of great significance to design and develop a Mini-LED packaging glue with a larger light output angle without affecting the light efficiency. Summary of the invention

[0005] To solve the above technical problems, the present invention provides a volcanic polysiloxane encapsulation glue and its preparation method and application. The volcanic polysiloxane encapsulation glue of the present invention has high stability, can greatly improve the light output angle, increase the chip spacing, reduce the chip usage, reduce costs, and will not affect the light effect.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a volcano-type polysiloxane encapsulating glue, wherein the raw materials for preparing the volcano-type polysiloxane encapsulating glue include: non-reactive long-chain polysiloxane and a hydrophobic filler.

[0008] The present invention adopts specific non-reactive long-chain polysiloxane and hydrophobic filler to jointly regulate the touch control property of the packaging glue, so that the viscosity and thixotropic stability of the polysiloxane packaging glue are greatly improved. During the packaging process, the appearance of a volcano-shaped lens can be obtained by dispensing, and the shape is uniform and stable; after curing, volcano-shaped lamp beads are obtained, so that the light-emitting angle of the chip is much larger than that of the hemispherical lamp beads, the utilization rate of the chip is improved, the amount of chips per unit area is reduced, and then the cost is reduced, the heat generation is reduced, and it is beneficial to increase the service life of the chip. At the same time, the volcano-shaped polysiloxane packaging glue can maintain good optical properties.

[0009] Preferably, the non-reactive long-chain polysiloxane has a structure as shown in Formula I:

[0010] (R 1 3 SiO 0.5 ) m (R 2 2 SiO) n Formula I;

[0011] In formula I, m and n are the number of chain links, and 0<m≤5, 100≤n≤200;

[0012] R 1 , R 2 The same or different, and each independently selected from any one of substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C6-C12 aryl; the substituted substituent is selected from H, C1-C5 alkyl.

[0013] In the structure shown in Formula I of the present invention, m and n are the number of chain links, and 0<m≤5 (for example, it can be 1, 2, 3, 4 or 5), 100≤n≤200 (for example, it can be 105, 110, 120, 130, 140, 150, 160, 170, 180, 190, 195, etc.); if n is less than 100, the viscosity is low and the thixotropic effect is not good. If it is greater than 200, the viscosity is too high, resulting in wire drawing during the preparation process, which is not conducive to actual production and use.

[0014] R 1 , R 2 The same or different, and each independently selected from any one of substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C6-C12 aryl; the substituted substituent is selected from H, C1-C5 alkyl.

[0015] Among them, in the same chain link, R 1 3 It means three R's 1 , R 1 You can choose the same or different; R2 2 It means 2 R 2 , R 2 You can choose to be the same or different; C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12; C6-C12 can be C6, C10 or C12; C1-C5 can be C1, C2, C3, C4 or C5.

[0016] In the present invention, the long-chain polysiloxane is selected from non-reactive long-chain polysiloxanes of a specific structure, which will not undergo addition or polymerization reactions with the branched alkenyl-containing polysiloxanes, but can be well compounded with specific hydrophobic fillers and branched alkenyl-containing polysiloxanes and other components through their molecular entanglement, thereby further improving the viscosity and thixotropic stability of the resulting polysiloxane volcano-type encapsulation glue. In the present invention, the non-reactive long-chain polysiloxane is further preferably a methyl non-reactive long-chain polysiloxane.

[0017] Preferably, the mass of hydroxyl groups in the hydrophobic filler is 0.8-1.5%, for example, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4% or 1.5%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0018] The present invention adopts a specific hydrophobic filler, and when the hydroxyl content is 0.8-1.5% of the mass of the hydrophobic filler, it can well inhibit the absorption of water, and at the same time ensure that the hydroxyl groups remaining on the surface of the filler can form hydrogen bonds between molecules, so as to achieve a good thixotropic effect. When the hydroxyl content is lower than 0.8%, due to the small hydroxyl content, it is easy to disperse. Although the hardness is greatly improved, its viscosity and thixotropic value are both low, and it cannot form an effective concave after dispensing, so it cannot form a volcano-type glue appearance; when the hydroxyl content is higher than 1.5%, due to the high hydroxyl content, it is easy to absorb water, resulting in a large height difference and a large concave depth difference of the volcano-type lens obtained after dispensing and curing, which leads to an unstable light output angle and poor light transmittance. Further, when the hydroxyl content is 1%, the thixotropic effect obtained is the best, and a highly stable volcano-type lens appearance can be obtained after dispensing, and the light output angle reaches the maximum.

[0019] Preferably, the mass ratio of the non-reactive long-chain polysiloxane to the hydrophobic filler is (0.8-1.5):1, for example, it can be 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable.

[0020] In the present invention, by compounding the non-reactive long-chain polysiloxane with a specific hydrophobic filler, the two can play a good synergistic role, thereby making the obtained volcano-type polysiloxane encapsulation glue have good comprehensive performance. The hydroxyl groups remaining on the surface of the filler treated with hydrophobicity can form hydrogen bonds between molecules, thereby achieving a thixotropic effect, and the non-reactive long-chain polysiloxane provides a molecular entanglement effect on the basis of the hydrogen bond, so that the filler treated with specific hydrophobicity can be evenly dispersed in the system, thereby greatly enhancing the thixotropic stability of the obtained polysiloxane encapsulation glue.

[0021] Further, when the mass ratio of non-reactive long-chain polysiloxane to hydrophobic filler is (0.8-1.5): 1, the two can play a synergistic role well, so that the obtained polysiloxane encapsulation glue has good viscosity and thixotropic stability, and can form a specific volcano-type lens appearance after dispensing, with a uniform and stable shape and a large light output angle. When the mass ratio of the two is lower than 0.8: 1, due to the low content of non-reactive long-chain polysiloxane, the depth of the concave formed is unstable, resulting in uneven light output after the chip passes through the lens; when the mass ratio of the two is greater than the mass ratio of the two is higher than 1.5: 1, due to the high content of non-reactive long-chain polysiloxane, the viscosity is large, and the aspect ratio is too high, resulting in a reduced light output angle; further, when the mass ratio of the two is 1: 1, the thixotropic effect is best.

[0022] Preferably, the viscosity of the packaging glue at 25° C. is 12000-20000 mPa·s, for example, it may be 12500 mPa·s, 13000 mPa·s, 14000 mPa·s, 15000 mPa·s, 16000 mPa·s, 17000 mPa·s, 18000 mPa·s, 19000 mPa·s or 19500 mPa·s, but is not limited to the listed values, and other unlisted data within the numerical range are equally applicable.

[0023] Preferably, the thixotropic index of the volcano-type polysiloxane encapsulation glue is 5.8-6.5, for example, it can be 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4 or 6.5, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable.

[0024] Preferably, the viscosity of the non-reactive long-chain polysiloxane at 25° C. is 2000-20000 MPa·s, for example, 3000 MPa·s, 4000 MPa·s, 6000 MPa·s, 8000 MPa·s, 10000 MPa·s, 12000 MPa·s, 15000 MPa·s, 18000 MPa·s or 20000 MPa·s, not limited to the listed values, and other unlisted data within the numerical range are also applicable, preferably 4000-18000 MPa·s, and more preferably 6000-15000 MPa·s.

[0025] Preferably, the refractive index of the non-reactive long-chain polysiloxane is 1.41-1.54, for example, it can be 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.50, 1.52, 1.53 or 1.54, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable, preferably 1.43-1.54, and more preferably 1.45-1.50.

[0026] Preferably, based on the total mass of the volcano-type siloxane encapsulation glue as 100%, the content of the non-reactive long-chain polysiloxane is 4-8%, for example, it can be 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% or 8%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0027] In the present invention, when the content of non-reactive long-chain polysiloxane is 4-8% of the total mass of the packaging glue, better technical effects can be obtained. When its content is lower than 4%, due to the small amount of non-reactive long-chain polysiloxane, the molecular entanglement effect is not strong, resulting in poor storage stability and thixotropic properties of the glue; when its content is higher than 8%, the amount of non-reactive long-chain polysiloxane is too large, and it is easy to precipitate after curing, resulting in the surface of the packaging glue being sticky, foggy, and dusty after curing, affecting the light transmittance, and also affecting the formation of a network structure between the hydrophobically treated fillers, which is not conducive to improving the thixotropic properties of the packaging glue.

[0028] Preferably, the hydrophobic filler comprises fumed silica with a hydrophobic surface treatment.

[0029] In the present invention, the hydrophobic filler is preferably fumed silica with a hydrophobic surface treatment. Ordinary silica and hydrophilic silica have a large number of silanol groups on their surfaces, which will cause a large amount of water to adhere over time, resulting in reduced storage stability, and further leading to unstable thixotropic properties, sedimentation in the later stage of storage, and other problems. The present invention uses silica with a hydrophobic surface treatment to have a hydroxyl content of 0.8-1.5%, which can well inhibit the absorption of water, while ensuring that the hydroxyl groups remaining on the surface of the silica can form hydrogen bonds between molecules, achieving a good thixotropic effect.

[0030] Preferably, the particle size of the hydrophobic filler is 1-100 nm, for example, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 50 nm, 80 nm or 100 nm, not limited to the listed values, and other unlisted data within the numerical range are also applicable, preferably 1-50 nm.

[0031] In the present invention, if the particle size of the hydrophobic filler is too large, although its dispersibility will be improved, its thixotropy will be deteriorated, and its hardness will be reduced, thereby resulting in poor overall performance.

[0032] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the hydrophobic filler is 1-20%, for example, it can be 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18% or 20%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0033] Preferably, the raw materials for preparing the volcano-type polysiloxane encapsulation glue include the following components in percentage by mass:

[0034]

[0035] Preferably, the alkenyl-containing polysiloxane comprises a branched alkenyl-containing polysiloxane and / or a linear alkenyl-containing polysiloxane.

[0036] Preferably, the branched alkenyl-containing polysiloxane has a structure shown in Formula II:

[0037] (R 3 3 SiO 0.5 ) a (R 4 2 SiO) b (R 5 SiO 1.5 ) c (SiO 2 ) d Formula II;

[0038] In formula II, a, b, c, and d are molar ratios, and 0<a≤0.5 (for example, 0.1, 0.2, 0.3, 0.4, or 0.5), 0<b≤1 (for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0), 0<c≤1 (for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0), and 0≤d≤0.5 (for example, 0.1, 0.2, 0.3, 0.4, or 0.5);

[0039] R 3 , R 4 , R 5 are each independently selected from any one of a substituted or unsubstituted C2-C12 alkene group, a substituted or unsubstituted C1-C12 alkyl group, and a substituted or unsubstituted C6-C12 aryl group, and R 3 , R 4 or R 5 Contains at least one olefin group; the substituted substituent is selected from H, C1-C5 alkyl.

[0040] In the present invention, R 3 3 It means three R's 3 , R 3 You can choose the same or different; R 4 2 It means 2 R 4 , R 4 You can choose to be the same or different; C2-C12 can be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12; C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12; C6-C12 can be C6, C10 or C12; C1-C5 can be C1, C2, C3, C4 or C5.

[0041] Preferably, the viscosity of the branched alkenyl-containing polysiloxane at 25° C. is 2000-100000 MPa·s, for example, it may be 5000 MPa·s, 8000 MPa·s, 10000 MPa·s, 20000 MPa·s, 30000 MPa·s, 40000 MPa·s, 50000 MPa·s, 60000 MPa·s, 80000 MPa·s, or 100000 MPa·s, not limited to the listed values, and other unlisted data within the numerical range are equally applicable, preferably 5000-80000 MPa·s, and more preferably 10000-50000 MPa·s.

[0042] Preferably, the refractive index of the branched alkenyl-containing polysiloxane is 1.41-1.54, for example, it can be 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.50, 1.52, 1.53 or 1.54, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable, preferably 1.43-1.54, and more preferably 1.45-1.50.

[0043] Preferably, the mass of the alkenyl group in the branched alkenyl-containing polysiloxane is 1-6% (i.e., the mass of the vinyl group in the branched alkenyl-containing polysiloxane is 1-6% of the mass of the branched alkenyl-containing polysiloxane), for example, it can be 1%, 2%, 3%, 4%, 5% or 6%, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable.

[0044] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the branched alkenyl-containing polysiloxane is 40-60%, for example, it can be 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56% or 58%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0045] Preferably, the straight-chain alkenyl-containing polysiloxane has a structure shown in Formula III:

[0046] (R 6 3 SiO 0.5 ) f (R 7 2 SiO) g Formula III;

[0047] In formula III, f and g are the number of chain links, and 0<f≤5 (for example, it can be 1, 2, 3, 4 or 5), 0<g≤10 (for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10);

[0048] R 6 , R 7 are the same or different and are each independently selected from any one of a substituted or unsubstituted C2-C12 alkene group, a substituted or unsubstituted C1-C12 alkyl group, and a substituted or unsubstituted C6-C12 aryl group, and R 6 , R 7 Contains at least one olefin group; the substituted substituent is selected from H, C1-C5 alkyl.

[0049] In the present invention, in the same link, R 6 3 It means three R's 6 , R 6You can choose the same or different; R 7 2 It means 2 R 7 , R 7 You can choose to be the same or different; C2-C12 can be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12; C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12; C6-C12 can be C6, C10 or C12; C1-C5 can be C1, C2, C3, C4 or C5.

[0050] Preferably, the viscosity of the straight-chain alkenyl-containing polysiloxane at 25° C. is 50-5000 MPa·s, for example, it may be 60 MPa·s, 80 MPa·s, 100 MPa·s, 300 MPa·s, 500 MPa·s, 800 MPa·s, 1000 MPa·s, 3000 MPa·s or 5000 MPa·s, not limited to the listed values, and other unlisted data within the numerical range are also applicable, preferably 100-2000 MPa·s, and more preferably 500-1000 MPa·s.

[0051] Preferably, the refractive index of the straight-chain alkenyl-containing polysiloxane is 1.41-1.54, for example, it can be 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.50, 1.52, 1.53 or 1.54, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable, preferably 1.43-1.54, and more preferably 1.45-1.50.

[0052] Preferably, the mass of alkenyl groups in the straight-chain alkenyl-containing polysiloxane is 1-6% (i.e., the mass of alkenyl groups in the straight-chain alkenyl-containing polysiloxane is 1-6% of the mass of the straight-chain alkenyl-containing polysiloxane), for example, it can be 1%, 2%, 3%, 4%, 5% or 6%, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable.

[0053] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the straight-chain alkenyl-containing polysiloxane is 1-10%, for example, it can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0054] Preferably, the hydrogen-containing polysiloxane has a structure shown in Formula IV:

[0055] (R 8 3 SiO0.5 ) h (R 9 2 SiO) i Formula IV;

[0056] In formula IV, h and i are the number of links, and 0<h≤5 (for example, it can be 1, 2, 3, 4 or 5), 0<i≤20 (for example, it can be 1, 3, 5, 7, 10, 12, 15, 18 or 20, etc.);

[0057] R 8 , R 9 are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C6-C12 aryl, and R 8 , R 9 Contains at least one hydrogen; the substituted substituent is selected from H, C1-C5 alkyl.

[0058] In the present invention, R 8 3 It means three R's 8 , R 8 You can choose the same or different; R 9 2 It means 2 R 9 , R 9 You can choose to be the same or different; C1-C12 can be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11 or C12; C6-C12 can be C6, C10 or C12; C1-C5 can be C1, C2, C3, C4 or C5.

[0059] The number of chain links (also called the number of repeating units or degree of polymerization) described in the present invention refers to the number of basic structural units that appear repeatedly in a polymer molecule. The molar ratio refers to the ratio of different types of basic structural units in a polymer.

[0060] Preferably, the viscosity of the hydrogen-containing polysiloxane at 25° C. is 50-5000 MPa·s, for example, 60 MPa·s, 80 MPa·s, 100 MPa·s, 300 MPa·s, 500 MPa·s, 1000 MPa·s, 1500 MPa·s, 3000 MPa·s or 4500 MPa·s, not limited to the listed values, and other unlisted data within the numerical range are also applicable, preferably 100-2000 MPa·s, and more preferably 100-500 MPa·s.

[0061] Preferably, the refractive index of the hydrogen-containing polysiloxane is 1.41-1.54, for example, it can be 1.42, 1.43, 1.44, 1.45, 1.46, 1.47, 1.48, 1.50, 1.52, 1.53 or 1.54, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable, preferably 1.43-1.54, and further 1.45-1.50.

[0062] Preferably, the mass of hydrogen in the hydrogen-containing polysiloxane is 0.1-1% (i.e., the mass of hydrogen in the hydrogen-containing polysiloxane is 1-6% of the mass of the hydrogen-containing polysiloxane), for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0063] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the hydrogen-containing polysiloxane is 10-30%, for example, it can be 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0064] Preferably, the catalyst comprises a platinum catalyst.

[0065] Preferably, the platinum catalyst includes any one of a chloroplatinic acid catalyst, a Karstedt platinum catalyst or a Willing process catalyst (Willing platinum catalyst) or a combination of at least two thereof.

[0066] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the catalyst is 0.1-0.5%, for example, it can be 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45% or 0.5%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0067] Preferably, the raw materials for preparing the volcano-type polysiloxane encapsulation glue also include auxiliary agents.

[0068] Preferably, the auxiliary agent comprises an adhesive and / or an adhesion promoter.

[0069] Preferably, the adhesive comprises a silane adhesive.

[0070] Preferably, the silane adhesive includes any one of 3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinyltriacetoxysilane or 3-mercaptopropylmethyldimethoxysilane, or a combination of at least two thereof.

[0071] The adhesive selected in the present invention is a substance that can be combined with an organic group and an inorganic group. The end of the adhesive combined with the inorganic group is hydrolyzed to generate a hydroxyl group, which is then combined with the inorganic group on the surface of the substrate.

[0072] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the adhesive is 0.1-5%, for example, it can be 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0073] Preferably, the adhesion promoter includes any one or a combination of at least two of tripropyl borate, tributyl borate, tetrakis(triethanolamine) zirconium, zirconium n-propoxide, neoalkoxy tris(ethylenediamine N-ethoxy) zirconate, neoalkoxy tris(neodecanoyloxy) zirconate, neoalkoxy tris(p-aminophenoxy) titanate, neoalkoxy tris(dioctyl pyrophosphate) titanate, tetraneoalkoxy bis(didecyl phosphite) titanate, bis(acetylacetonato) isopropyl aluminate or epoxy silane oligomer.

[0074] The adhesion promoter in the present invention can improve the activity of reactive groups such as amino groups and hydroxyl groups or other active groups, thereby improving the adhesion activity of the adhesive and giving the product better adhesion.

[0075] Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue as 100%, the content of the adhesion promoter is 0.1-5%, for example, it can be 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0076] Preferably, the raw materials for preparing the volcano-type polysiloxane encapsulation glue include the following components in percentage by mass:

[0077]

[0078]

[0079] The volcanic polysiloxane encapsulation glue provided by the present invention solves the technical problem of low light output angle in the prior art. By selecting the viscosity of the specific raw materials, the situation that the viscosity is too small or too large will lead to inconsistent shapes is avoided, and the encapsulation glue with uniform encapsulation shape is obtained; at the same time, by selecting and optimizing the type and content of the specific raw materials, the problems such as the thixotropic instability caused by the addition of filler gas-phase silica due to its difficulty in dispersion and the excessive addition content that easily affects the light transmittance of the encapsulation glue are solved, and the encapsulation glue with stable thixotropic value is obtained, thereby effectively avoiding the large force of the piezoelectric valve nozzle during the dispensing process, and the inconsistent inner concave depth caused by the unstable thixotropy of the encapsulation glue, which in turn affects the light output effect and causes a low yield, and the encapsulation glue with stable inner concave is obtained.

[0080] In a second aspect, the present invention provides a method for preparing the volcano-type polysiloxane encapsulation glue as described in the first aspect, the preparation method comprising the following steps:

[0081] The components including non-reactive long-chain polysiloxane and hydrophobic filler are mixed and degassed to obtain the volcano-type polysiloxane encapsulating glue.

[0082] Preferably, the mixing is performed under stirring.

[0083] Preferably, the mixing is performed by first stirring the component including the hydrophobic filler at a high speed, and then adding the component including the non-reactive long-chain polysiloxane and stirring at a low speed.

[0084] Preferably, the preparation method of the volcano-type polysiloxane encapsulation glue comprises the following steps: dispersing olefin-containing polysiloxane, hydrogen-containing polysiloxane, and hydrophobic filler at high speed, and then adding a catalyst, an adhesive, a non-reactive long-chain polysiloxane, and an adhesion promoter and dispersing them at low speed to obtain the volcano-type polysiloxane encapsulation glue.

[0085] Preferably, the rotation speed of the high-speed stirring is 1200-1600 rpm, for example, it can be 1250 rpm, 1300 rpm, 1350 rpm, 1400 rpm, 1450 rpm, 1500 rpm, 1550 rpmn or 1600 rpm, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0086] Preferably, the high-speed stirring time is 0.5-2 h, for example, 0.5 h, 1 h, 1.5 h or 2 h, and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0087] Preferably, the rotation speed of the low-speed stirring is 400-600 rpm, for example, it can be 420 rpm, 450 rpm, 480 rpm, 500 rpm, 520 rpm, 550 rpm, 580 rpm or 600 rpm, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0088] Preferably, the low-speed stirring time is 0.5-2 h, for example, 0.5 h, 1 h, 1.5 h or 2 h, and is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0089] In the specific preparation method of the volcano-type polysiloxane encapsulating glue provided by the present invention, the filler and the branched alkenyl-containing polysiloxane, the straight-chain alkenyl-containing polysiloxane and the hydrogen-containing polysiloxane are first stirred and mixed at a high speed (1200-1600 rpm) in a disperser to ensure that the filler is dispersed as evenly as possible; then the catalyst, the adhesive, the long-chain polysiloxane and the adhesion promoter are added and stirred and mixed at a low speed (400-600 rpm), which can effectively avoid the heat generated by the filler and other components during the high-speed stirring and mixing process from affecting some temperature-sensitive components, thereby facilitating the effectiveness and stability of the performance of the obtained volcano-type polysiloxane encapsulating glue.

[0090] In a third aspect, the present invention provides an application of the volcano-type polysiloxane encapsulation glue as described in the first aspect in LED, especially in the field of Mini-LED.

[0091] Compared with the prior art, the present invention has at least the following beneficial effects:

[0092] (1) The present invention adopts specific non-reactive long-chain polysiloxane and hydrophobic filler to control the touch control property of the packaging glue, so that the viscosity and thixotropic stability of the polysiloxane packaging glue are greatly improved. During the packaging process, the appearance of a volcano-shaped lens can be obtained by dispensing, and the shape is uniform and stable; after curing, a volcano-shaped lamp bead is obtained, so that the light-emitting angle of the chip is much larger than that of the hemispherical lamp bead, thereby improving the chip utilization rate and reducing the amount of chips per unit area, thereby reducing costs and reducing heat generation, which is beneficial to increasing the service life of the chip. At the same time, the polysiloxane volcano-shaped packaging glue can maintain good optical properties.

[0093] (2) The present invention compounds the non-reactive long-chain polysiloxane with a specific hydrophobic filler so that the two can play a good synergistic role, thereby making the obtained volcano-type polysiloxane encapsulation glue have good comprehensive performance. The residual hydroxyl groups on the surface of the hydrophobic filler can form hydrogen bonds between molecules, thereby achieving a thixotropic effect, and the non-reactive long-chain polysiloxane provides a molecular entanglement effect based on the hydrogen bond, so that the specific hydrophobic filler can be evenly dispersed in the system, thereby greatly enhancing the thixotropic stability of the obtained polysiloxane encapsulation glue. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 This is a physical picture of the volcano-type polysiloxane encapsulation glue dispensing obtained in Example 1;

[0095] Figure 2 Schematic diagram of the volcanic polysiloxane encapsulation glue obtained in Example 1 after dispensing and curing; wherein, 1, cured glue; 2, light-emitting chip; 3, ink; 4, substrate;

[0096] Figure 3 Schematic diagram of the corresponding test indexes of the volcano-type polysiloxane encapsulation glue after curing; wherein D is the spot diameter; H is the spot diameter; 1 , height; H 2 , concave depth. DETAILED DESCRIPTION

[0097] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0098] Unless otherwise specified, the raw materials used in the specific examples and comparative examples are commercially available, and information on some of the raw materials is as follows:

[0099] (1) The branched alkenyl-containing polysiloxane is represented by A, then

[0100] A-1: (ViMe 2 SiO 0.5 ) 0.2 (PhMeSiO) 0.1 (MeSiO 1.5 ) 0.7 (PhSiO 1.5 ) 0.3 , the viscosity is 40000mPa.s, wherein Vi represents vinyl, Me represents methyl, and Ph represents phenyl;

[0101] A-2; (ViMe 2 SiO 0.5 ) 0.2 (Me2 SiO) 0.4 (MeSiO 1.5 ) 0.5 (PhSiO 1.5 ) 0.5 , the viscosity is 15000mpa.s, wherein Vi represents vinyl, Me represents methyl, and Ph represents phenyl;

[0102] A-1 and A-2 were purchased from Anhui Aiyota Silicone Oil Co., Ltd.;

[0103] (2) The straight chain alkenyl-containing polysiloxane is represented by B, which is (ViMe 2 SiO 0.5 ) 2 (PhMeSiO) 4 (Me 2 SiO) 6 , wherein Vi represents vinyl, Me represents methyl, and Ph represents phenyl; purchased from Anhui Aiyota Silicone Oil Co., Ltd.;

[0104] (3) Hydrogen-containing polysiloxane is represented by C, which is (HMe 2 SiO 0.5 ) 2 (PhMeSiO) 2 (Me 2 SiO) 2 , wherein Me represents methyl and Ph represents phenyl; purchased from Anhui Aiyota Silicone Oil Co., Ltd.;

[0105] (4) Catalyst D was purchased from Shanghai Neutron Star Chemical Technology Co., Ltd., model PC-54, with a Pt concentration of 2000 ppm;

[0106] (5) The adhesive is represented by E, which is 3-glycidyloxypropyltriethoxysilane;

[0107] (6) Long-chain polysiloxane is represented by F, then

[0108] F-1: (Me 3 SiO 0.5 ) 2 (PhMeSiO) 10 (Me 2 SiO) 18 , wherein Me represents a methyl group and Ph represents a phenyl group;

[0109] F-2: Reactive long-chain polysiloxane, (ViMe 2 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO)80 , wherein Vi represents vinyl, Me represents methyl, and Ph represents phenyl;

[0110] F-3: Reactive long-chain polysiloxane, (HMe 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 , wherein Me represents a methyl group and Ph represents a phenyl group;

[0111] F-4: (Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 , wherein Me represents a methyl group and Ph represents a phenyl group;

[0112] F-5: (PhMe 2 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 , wherein Ph represents a phenyl group and Me represents a methyl group;

[0113] F-6: (Et 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 , wherein Et represents ethyl, Me represents methyl, and Ph represents phenyl;

[0114] F-1~F-6 were purchased from Guangzhou Chensi New Material Technology Co., Ltd.;

[0115] (7) Adhesion promoter, denoted by G, was purchased from Nanjing Nengde New Material Technology Co., Ltd., model number HE87M;

[0116] (8) The filler is represented by H, then

[0117] H-1: fumed silica with a surface hydrophobic treatment of dimethyldichlorosilane, particle size of 15 nm, hydroxyl content of 1%;

[0118] H-2: fumed silica without surface treatment, particle size 15 nm, hydroxyl content 2%;

[0119] H-3: Fumed silica with surface deep treated with dimethyldichlorosilane, particle size 15nm, hydroxyl content 0.5%;

[0120] H-4: fumed silica with a surface hydrophobic treatment with dimethyldichlorosilane, a particle size of 15 nm, and a hydroxyl content of 0.8%;

[0121] H-5: fumed silica with a surface hydrophobic treatment with dimethyldichlorosilane, a particle size of 15 nm, and a hydroxyl content of 1.5%.

[0122] H-1~H-5 were purchased from Huifu Nano.

[0123] Example 1

[0124] This embodiment provides a volcanic polysiloxane encapsulation glue, and the raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass:

[0125]

[0126]

[0127] The preparation method of the volcano-type polysiloxane encapsulation glue comprises the following steps:

[0128] A-1, B, C, and H-1 were mixed, dispersed in a high-speed disperser at 1500 rpm for 1 hour, then D, E, F-4, and G were added and mixed, stirred at a high-speed disperser at 500 rpm for 1 hour, and then degassed to obtain the volcano-type polysiloxane encapsulation glue.

[0129] Example 2

[0130] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 only in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) was replaced by F-5((PhMe 2 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ), other components, contents and preparation methods are the same as those in Example 1.

[0131] Example 3

[0132] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 only in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) replaced by F-6((Et 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ), other components, contents and preparation methods are the same as those in Example 1.

[0133] Example 4

[0134] This embodiment provides a volcanic polysiloxane encapsulation glue, and the raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass:

[0135]

[0136]

[0137] The preparation method of the volcano-type polysiloxane encapsulation glue is the same as that in Example 1.

[0138] Example 5

[0139] This embodiment provides a volcanic polysiloxane encapsulation glue, and the raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass:

[0140]

[0141] The preparation method of the volcano-type polysiloxane encapsulation glue is the same as that in Example 1.

[0142] Example 6

[0143] This embodiment provides a volcano-type polysiloxane encapsulation glue, which differs from Example 1 only in that H-1 (hydrophobically treated fumed silica (hydroxyl content is 1%)) is replaced by H-4 (hydrophobically treated fumed silica (hydroxyl content is 0.8%)), and the other components, contents and preparation methods are the same as those in Example 1.

[0144] Example 7

[0145] This embodiment provides a volcano-type polysiloxane encapsulation glue, which differs from Example 1 only in that H-1 (hydrophobically treated fumed silica (hydroxyl content is 1%)) is replaced by H-5 (hydrophobically treated fumed silica (hydroxyl content is 1.5%)), and the other components, contents and preparation methods are the same as those in Example 1.

[0146] Example 8

[0147] This comparative example provides a polysiloxane encapsulation glue, which differs from Example 1 only in that H-1 (hydrophobically treated fumed silica (hydroxyl content is 1%)) is replaced by H-3 (hydrophobically treated fumed silica (hydroxyl content is 0.5%)), and the other components, contents and preparation methods are the same as those in Example 1.

[0148] Example 9

[0149] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) was adjusted from 5% to 3.3%, and the content of H-1 (hydrophobically treated fumed silica (hydroxyl content of 1%)) was adjusted from 5% to 6.7%. The other components, contents and preparation methods were the same as those in Example 1.

[0150] Example 10

[0151] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) was adjusted from 5% to 4.4%, and the content of H-1 (hydrophobically treated fumed silica (hydroxyl content of 1%)) was adjusted from 5% to 5.6%. The other components, contents and preparation methods were the same as those in Example 1.

[0152] Embodiment 11

[0153] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO)80 ) was adjusted from 5% to 6%, and the content of H-1 (hydrophobically treated fumed silica (hydroxyl content of 1%)) was adjusted from 5% to 4%. The other components, contents and preparation methods were the same as those in Example 1.

[0154] Example 12

[0155] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) was adjusted from 5% to 6.6%, and the content of H-1 (hydrophobically treated fumed silica (hydroxyl content of 1%)) was adjusted from 5% to 3.4%. The other components, contents and preparation methods were the same as those in Example 1.

[0156] Example 13

[0157] This embodiment provides a volcanic polysiloxane encapsulation glue, and the raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass:

[0158]

[0159] The preparation method of the volcano-type polysiloxane encapsulation glue is the same as that in Example 1.

[0160] Embodiment 14

[0161] This embodiment provides a volcanic polysiloxane encapsulation glue, and the raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass:

[0162]

[0163]

[0164] The preparation method of the volcano-type polysiloxane encapsulation glue is the same as that in Example 1.

[0165] Embodiment 15

[0166] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 in that A-1 ((ViMe 2 SiO 0.5 ) 0.2 (PhMeSiO) 0.1 (MeSiO 1.5 ) 0.7 (PhSiO1.5 ) 0.3 ) is replaced by A-2((ViMe 2 SiO 0.5 ) 0.2 (Me 2 SiO) 0.4 (MeSiO 1.5 ) 0.5 (PhSiO 1.5 ) 0.5 ), other components, contents and preparation methods are the same as those in Example 1.

[0167] Example 16

[0168] This embodiment provides a volcanic polysiloxane encapsulation glue, which is different from the embodiment 1 only in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) is replaced by F-1((Me 3 SiO 0.5 ) 2 (PhMeSiO) 10 (Me 2 SiO) 18 ), other components, contents and preparation methods are the same as those in Example 1.

[0169] Comparative Example 1

[0170] This comparative example provides a polysiloxane encapsulation glue, which differs from Example 1 only in that F-4((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ) is replaced by F-2((ViMe 2 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ), other components, contents and preparation methods are the same as those in Example 1.

[0171] Comparative Example 2

[0172] This comparative example provides a polysiloxane encapsulation glue, which differs from Example 1 only in that F-4((Me 3 SiO 0.5 ) 2(PhMeSiO) 30 (Me 2 SiO) 80 ) replaced by F-3((HMe 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ), other components, contents and preparation methods are the same as those in Example 1.

[0173] Comparative Example 3

[0174] This comparative example provides a polysiloxane encapsulation glue, which differs from Example 1 only in that F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ), and its reduced content was allocated to H-1 (hydrophobically treated fumed silica (hydroxyl content of 1%)), and the other components, contents and preparation methods were the same as those in Example 1.

[0175] Comparative Example 4

[0176] This comparative example provides a polysiloxane encapsulation glue, which differs from Example 1 only in that H-1 (hydrophobically treated fumed silica (hydroxyl content of 1%)) is not added, and its reduced content is distributed to F-4 ((Me 3 SiO 0.5 ) 2 (PhMeSiO) 30 (Me 2 SiO) 80 ), other components, contents and preparation methods are the same as those in Example 1.

[0177] Comparative Example 5

[0178] This comparative example provides a polysiloxane encapsulation glue, which differs from Example 1 only in that H-1 (hydrophobically treated fumed silica (hydroxyl content is 1%)) is replaced by H-2 (fumed silica without hydrophobic treatment (hydroxyl content is 2%)), and the other components, contents and preparation methods are the same as those in Example 1.

[0179] Directions:

[0180] When in use, the polysiloxane encapsulation glue obtained in Examples 1-16 and Comparative Examples 1-5 is dispensed and then cured.

[0181] Specific application method:

[0182] The substrate was baked at 150°C for 1 hour to volatilize the volatile substances on the surface of the substrate. The polysiloxane encapsulation glue obtained in Examples 1-16 and Comparative Examples 1-5 was dispensed on the substrate chip surface using a piezoelectric injection valve, and the dispensed samples were cured at 150°C for 1 hour before being taken out.

[0183] like Figure 1 As shown, the pattern after dispensing in Example 1 is a volcano shape, and the schematic diagram after curing is as follows Figure 2 shown.

[0184] The performance of the polysiloxane encapsulation glue obtained in the above Examples 1-16 and Comparative Examples 1-5 was tested, and the test method / standard is as follows:

[0185] Glue viscosity test: Use a 25mm flat plate fixture of the rheometer, a fixed gap of 1000μm, a temperature of 25℃, and a shear rate of 20s -1 The viscosity of glue is tested at a rotation speed of ;

[0186] Thixotropic index test of glue: Use a 25mm flat plate fixture of the rheometer, a fixed gap of 1000μm, and a shear rate of 1s -1 The glue viscosity η is tested at a speed of 1 and 10s -1 The viscosity at the speed is η 10 , thixotropic index = η 1 / η 10 ;

[0187] Appearance test after curing: Visually observe the appearance after curing and give the following evaluation:

[0188] When the appearance of the encapsulation glue after curing meets 0.32≤H 1 / D≤0.36,0.15≤H 2 / H 1 When ≤0.2, it is judged as volcanic type (○); otherwise it is judged as non-volcanic type (×). 1 , D are the height and point diameter averages of the encapsulation glue after curing, H 2 is the mean value of the concave depth of the encapsulant after curing;

[0189] Transmittance test after curing: Test according to the method in the national standard GB / T 2410-2008 Transparent Plastic Transmittance Determination;

[0190] Hardness test after curing: Pour polysiloxane encapsulation glue into a cylindrical mold with a length and width of 30 mm and a thickness of 10 mm, and cure it at 150°C for 1 hour. Take out the solid glue block and put it in a 30°C water bath. After the temperature stabilizes, use a Shore D hardness tester to test the hardness of the glue block in accordance with the national standard GB / T 2411-2008.

[0191] Spot diameter test after curing: 100 spots of glue were cured. After curing, the spot diameter D was tested under an electron microscope. Figure 3 As shown, the mean value M of the point diameter is calculated D and the range R D ;

[0192] Height test after curing: 100 glue points are cured, and after curing, the glue is cut in half and placed under an electron microscope to test the height H. 1 ,like Figure 3 As shown, the mean value M of the point diameter is calculated H1 and the range R H1 ;

[0193] After curing, the concave depth test was performed: 100 glue points were cured, and after curing, the glue was cut in half and placed under an electron microscope to test the concave depth H. 2 ,like Figure 3 As shown, the mean value M of the point diameter is calculated H2 and the range R H2 ;

[0194] Light angle test after curing: Use a distribution photometer to test the light distribution curve, calculate the angle of light intensity, and get the light angle.

[0195] The test results are shown in Table 1 and Table 2.

[0196] Table 1

[0197]

[0198] Table 2

[0199]

[0200]

[0201] “ / ” in the table means no data.

[0202] From the test results in Table 1 and Table 2, we can see that:

[0203] (1) It can be seen from Examples 1 to 5 that the present invention obtains a novel volcano-type polysiloxane encapsulation glue with high thixotropic stability by specifically selecting a non-reactive long-chain polysiloxane with a specific structure and a hydrophobic filler and scientifically matching other components. The viscosity of the volcano-type polysiloxane encapsulation glue at 25°C is 12530-15029 mPa·s, and the thixotropic index is 5.9-6.2. At the same time, the specific volcano-type polysiloxane encapsulation glue has good hardness and light transmittance (higher than 95%), a light output angle greater than 170°C, a uniform shape, and the measured point diameter, height, and concave depth data are concentrated. The point diameter range is not higher than 0.0821 mm, the height range is not higher than 0.0523 mm, and the concave depth range is not higher than 0.0253 mm, thereby increasing the chip spacing, reducing the chip usage, and thus reducing costs and heat generation.

[0204] (2) By comparing Example 1 with Examples 9-12, it can be seen that in the present invention, when the mass ratio of the specific non-reactive long-chain polysiloxane to the hydrophobic filler is (0.8-1.5):1, the obtained volcano-type polysiloxane encapsulation glue can have a larger light output angle, and the comprehensive properties such as light transmittance, hardness and thixotropic stability are better; when the mass ratio of the two is lower than 0.8:1, the filler content is high, the depth of the formed concave is unstable, resulting in uneven light output of the chip after passing through the lens; when the mass ratio of the two is higher than 1.5:1, the content of the long-chain polysiloxane is high, the viscosity is large, and the aspect ratio (i.e., H 1 / D) is too high, resulting in a decrease in the light output angle.

[0205] (3) By comparing Example 1 with Examples 13 and 14, it can be seen that when the ratio of non-reactive long-chain polysiloxane to hydrophobic filler is fixed and other raw material components are within the specific content range of the present invention, when the amount of non-reactive long-chain polysiloxane is lower or higher than 4-8% of the polysiloxane encapsulation glue, it will lead to a decrease in its comprehensive performance. Example 14 shows that when the amount of non-reactive long-chain polysiloxane is lower than 4%, the storage stability and thixotropic properties of the glue are poor; Example 13 shows that when the amount of non-reactive long-chain polysiloxane is higher than 8%, it is easy to precipitate after curing, resulting in the surface of the encapsulation glue being sticky, foggy, and dusty after curing, affecting the transmittance, and also affecting the formation of a network structure between the hydrophobically treated silica, which is not conducive to the thixotropy of the encapsulation glue.

[0206] (4) By comparing Example 1 with Example 15, it can be seen that when the viscosity of the branched alkenyl-containing polysiloxane is lower than the specific viscosity range of the branched alkenyl-containing polysiloxane in the present invention, the viscosity and thixotropic index of the polysiloxane encapsulating glue obtained are not high, and the volcano-type polysiloxane encapsulating glue with the specific novel volcano-type appearance in the present invention cannot be formed.

[0207] (5) By comparing Example 1 with Example 2, Example 3 with Comparative Example 1 and Comparative Example 2, it can be seen that the polysiloxane encapsulation glues obtained in Comparative Example 1 and Comparative Example 2 cannot form a volcano-shaped lens in appearance after dispensing, and have poor stability (the height difference is greater than 0.09 mm), which well demonstrates that the specific selection of the non-reactive long-chain polysiloxane of the present invention can obtain a new volcano-shaped polysiloxane encapsulation glue. Furthermore, by comparing Examples 1-3 with Example 16, it can be shown that the non-reactive long-chain polysiloxane of the specific structure of the present invention can well form a volcano-shaped lens in appearance.

[0208] (6) By comparing Example 1 with Comparative Examples 3 and 4, it can be seen that Comparative Example 3 does not add non-reactive long-chain polysiloxane, but only increases the content of hydrophobic filler. Although it can be formed, the concave stability is poor and the light output angle is not high; Comparative Example 4 does not add hydrophobic filler, but only increases the content of non-reactive long-chain polysiloxane, the viscosity is low, and the aspect ratio (i.e., H 1 / D) is low, and no volcano-type lens is formed. This shows that the specific selection and combination of the non-reactive long-chain polysiloxane and the hydrophobic filler in the present invention enable the two to play a synergistic role, thereby obtaining a volcano-type polysiloxane encapsulation glue with good stability and a large light output angle.

[0209] (7) By comparing Example 1, Examples 6-8 with Comparative Example 5, it can be seen that the polysiloxane encapsulation glue obtained in Comparative Example 5 uses fumed silica without surface treatment as filler. Due to the high hydroxyl content, it is easy to absorb water, resulting in large height and depth differences of the volcano-shaped lens obtained after dispensing and curing, which leads to unstable light output angle and poor light transmittance of only 90.2%; the polysiloxane encapsulation glue obtained in Example 8 uses deeply treated fumed silica as filler. Due to the low hydroxyl content, it is easy to disperse. Although the hardness is greatly improved, its viscosity and thixotropy value are both low. After dispensing, it cannot form an effective concave, so it cannot form the appearance of a volcano-shaped glue. It shows that the selection of a hydrophobic filler with a specific hydroxyl content can help to obtain a volcano-shaped polysiloxane encapsulation glue with good light transmittance, uniform shape, and stable concave.

[0210] The present invention adopts specific non-reactive long-chain polysiloxane and hydrophobic filler to control the touch control property of the packaging glue, and scientifically matches branched alkenyl-containing polysiloxane of specific viscosity, so that the viscosity and thixotropic stability of the polysiloxane packaging glue are greatly improved. During the packaging process, the appearance of a volcano-type lens can be obtained by dispensing, and the shape is uniform and stable, and the light output angle is large, thereby increasing the chip spacing, reducing the chip usage, and further reducing the cost, reducing the heat generation, and being beneficial to increasing the service life of the chip.

[0211] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A volcanic polysiloxane encapsulation glue, characterized in that: The raw materials for preparing the volcano-type polysiloxane encapsulation glue include: non-reactive long-chain polysiloxane and hydrophobic filler.

2. The volcanic polysiloxane encapsulation glue according to claim 1, characterized in that: The non-reactive long-chain polysiloxane has a structure shown in Formula I: (R 1 3SiO 0.5 ) m (R 2 2SiO) n Formula I; In formula I, m and n are the number of chain links, and 0<m≤5, 100≤n≤200; R 1 , R 2 are the same or different and are each independently selected from any one of substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C6-C12 aryl; the substituted substituent is selected from H, C1-C5 alkyl; Preferably, the mass of hydroxyl groups in the hydrophobic filler is 0.8-1.5%; Preferably, the mass ratio of the non-reactive long-chain polysiloxane to the hydrophobic filler is (0.8-1.5):1; Preferably, the thixotropic index of the volcano-type polysiloxane encapsulation glue is 5.8-6.

5.

3. The volcano-type polysiloxane encapsulation glue according to claim 1 or 2, characterized in that: The viscosity of the non-reactive long-chain polysiloxane is 2000-20000 mpa·s, preferably 4000-18000 mpa·s, and more preferably 6000-15000 mpa·s; Preferably, the refractive index of the non-reactive long-chain polysiloxane is 1.41-1.54, preferably 1.43-1.54, and more preferably 1.45-1.50; Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue being 100%, the content of the non-reactive long-chain polysiloxane is 4-8%.

4. The volcano-type polysiloxane encapsulation glue according to any one of claims 1 to 3, characterized in that: The hydrophobic filler comprises fumed silica with a hydrophobic surface treatment; Preferably, the particle size of the hydrophobic filler is 1-100 nm, preferably 1-50 nm; Preferably, based on the total mass of the volcano-type polysiloxane encapsulating glue being 100%, the content of the hydrophobic filler is 1-20%.

5. The volcano-type polysiloxane encapsulation glue according to any one of claims 1 to 4, characterized in that: The raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass: Preferably, the alkenyl-containing polysiloxane comprises a branched alkenyl-containing polysiloxane and / or a linear alkenyl-containing polysiloxane; Preferably, the branched alkenyl-containing polysiloxane has a structure shown in Formula II: (R 3 3SiO 0.5 ) a (R 4 2SiO) b (R 5 SiO 1.5 ) c (SiO2) d Formula II; In formula II, a, b, c, and d are molar ratios, and 0<a≤0.5, 0<b≤1, 0<c≤1, 0≤d≤0.5; R 3 , R 4 , R 5 are each independently selected from any one of a substituted or unsubstituted C2-C12 alkene group, a substituted or unsubstituted C1-C12 alkyl group, and a substituted or unsubstituted C6-C12 aryl group, and R 3 , R 4 or R 5 Contains at least one olefin group; the substituted substituent is selected from H, C1-C5 alkyl; Preferably, the viscosity of the branched alkenyl-containing polysiloxane is 2000-100000 mPa·s, preferably 5000-80000 mPa·s, and more preferably 10000-50000 mPa·s; Preferably, the mass of alkenyl groups in the branched alkenyl-containing polysiloxane is 1-6%; Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue being 100%, the content of the branched alkenyl-containing polysiloxane is 40-60%; Preferably, the straight-chain alkenyl-containing polysiloxane has a structure shown in Formula III: (R 6 3SiO 0.5 ) f (R 7 2SiO) g Formula III; In formula III, f and g are the number of chain links, and 0<f≤5, 0<g≤10; R 6 , R 7 are the same or different and are each independently selected from any one of a substituted or unsubstituted C2-C12 alkene group, a substituted or unsubstituted C1-C12 alkyl group, and a substituted or unsubstituted C6-C12 aryl group, and R 6 , R 7 Contains at least one olefin group; the substituted substituent is selected from H, C1-C5 alkyl; Preferably, the viscosity of the linear alkenyl-containing polysiloxane is 50-5000 mPa·s, preferably 100-2000 mPa·s, and more preferably 500-1000 mPa·s; Preferably, the mass of alkenyl groups in the linear alkenyl-containing polysiloxane is 1-6%; Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue being 100%, the content of the straight-chain alkenyl-containing polysiloxane is 1-10%; Preferably, the hydrogen-containing polysiloxane has a structure shown in Formula IV: (R 8 3SiO 0.5 ) h (R 9 2SiO) i Formula IV; In formula IV, h and i are the number of chain links, and 0<h≤5, 0<i≤20; R 8 , R 9 are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C12 alkyl, substituted or unsubstituted C6-C12 aromatic hydrocarbon group, and R 8 , R 9 Contains at least one hydrogen; the substituted substituent is selected from H, C1-C5 alkyl; Preferably, the viscosity of the hydrogen-containing polysiloxane is 50-5000 mpa·s, preferably 100-2000 mpa·s, and further preferably 100-500 mpa·s; Preferably, the mass of hydrogen in the hydrogen-containing polysiloxane is 0.1-1%; Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue being 100%, the content of the hydrogen-containing polysiloxane is 10-30%; Preferably, the catalyst comprises a platinum catalyst; Preferably, based on the total mass of the volcano-type polysiloxane encapsulating glue being 100%, the content of the catalyst is 0.1-0.5%.

6. The volcano-type polysiloxane encapsulation glue according to claim 5, characterized in that: The raw materials for preparing the volcanic polysiloxane encapsulation glue also include auxiliary agents; Preferably, the auxiliary agent comprises an adhesive and / or an adhesion promoter; Preferably, the adhesive comprises a silane adhesive; Preferably, the content of the adhesive is 0.1-5% based on the total mass of the volcanic polysiloxane encapsulation glue as 100%; Preferably, based on the total mass of the volcano-type polysiloxane encapsulation glue being 100%, the content of the adhesion promoter is 0.1-5%.

7. The volcano-type polysiloxane encapsulation glue according to any one of claims 1 to 6, characterized in that: The raw materials for preparing the volcanic polysiloxane encapsulation glue include the following components in percentage by mass:

8. A method for preparing the volcano-type polysiloxane encapsulation glue according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The components including non-reactive long-chain polysiloxane and hydrophobic filler are mixed and degassed to obtain the volcano-type polysiloxane encapsulating glue.

9. The method for preparing the volcano-type polysiloxane encapsulation glue according to claim 8, characterized in that: The mixing is carried out under stirring; Preferably, the mixing is to first stir the component including the hydrophobic filler at a high speed, and then add the component including the non-reactive long-chain polysiloxane and stir at a low speed; Preferably, the speed of the high-speed stirring is 1200-1600 rpm; Preferably, the high-speed stirring time is 0.5-2h; Preferably, the rotation speed of the low-speed stirring is 400-600 rpm; Preferably, the low-speed stirring time is 0.5-2h.

10. Application of the volcano-type polysiloxane encapsulation glue as described in any one of claims 1 to 8 in Mini-LED.

Images