HK1116208B

HK1116208B - Silicone composition for encapsulating luminescent element and luminescent device

Info

Publication number: HK1116208B
Application number: HK08106451.1A
Authority: HK
Inventors: 望月纪久夫; 平井信男
Original assignee: 迈图高新材料日本合同公司
Priority date: 2005-01-24
Filing date: 2005-07-22
Publication date: 2012-11-09

Description

Silicone composition for encapsulating light-emitting element and light-emitting device

Technical Field

The present invention relates to a silicone composition for encapsulating a light-emitting element, which is used for encapsulating a light-emitting element such as a diode or a transistor, and a light-emitting device obtained using the same.

Background

In light-emitting devices such as light-emitting diodes (LEDs) and photocouplers, a light-emitting element sealing composition is required to have a function of protecting the light-emitting element from the outside and to be well and stably bonded to the light-emitting element or a supporting base material such as polyphthalamide or ceramics that supports the light-emitting element. In addition, high transparency is also required to prevent a decrease in luminance of the light-emitting element.

Conventionally, as such a sealing composition, for example, an epoxy resin or the like has been used. However, when an epoxy resin or the like is used, cracks or yellowing occurs and the luminance is lowered due to an increase in the amount of heat generation and a decrease in the wavelength of light accompanying the recent increase in luminance of LEDs and the like.

Therefore, an organopolysiloxane composition (silicone composition) is used as a sealing composition having excellent heat resistance and ultraviolet resistance. In particular, an addition reaction type silicone composition using hydrosilylation is widely used because it is cured in a short time by heating, and therefore, it is excellent in production efficiency and does not generate by-products during curing.

As an addition reaction type silicone composition, for example, patent document 1 describes a silicone composition containing: a diorganopolysiloxane containing at least 2 silicon-bonded alkenyl groups and containing SiO_4/2Unit, Vi (R)³)₂SiO_1/2Unit and R₃SiO_1/2Unit (wherein Vi represents vinyl group, R³Represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated bond), an organohydrogenpolysiloxane containing at least 2 hydrogen atoms bonded to silicon atoms in 1 molecule, and a platinum group metal-based catalyst.

However, the silicone composition described in patent document 1 has a larger linear expansion coefficient after curing than that of the supporting base material, and therefore has a problem that residual stress after heat curing is large, and peeling occurs at the interface between the cured product and the supporting base material or the supporting base material is deformed. (see, for example, patent document 1)

Patent document 1: japanese laid-open patent publication No. 2000-198930

Disclosure of Invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a silicone composition for encapsulating a light-emitting element, which has excellent adhesion between a cured product of the silicone composition for encapsulating a light-emitting element and a support base material, and a light-emitting device in which a light-emitting element is encapsulated by the cured product.

The silicone composition for encapsulating a light-emitting element according to embodiment 1 of the present invention is characterized in that: contains (A), (B) and (C), and has a linear expansion coefficient of 10 to 290 x 10 after curing^-6/° c; (A) average unit formula: (SiO)_4/2)_a(ViR₂SiO_1/2)_b(R₃SiO_1/2)_c(wherein Vi represents vinyl, R is the same or different substituted or unsubstituted 1-valent hydrocarbyl except alkenyl, a, b and c are each a positive number, and a/(a + b + c) is 0.2-0.6, b/(a + b + c) is 0.001-0.2) the organopolysiloxane containing vinyl of three-dimensional network structure shown; (B)1 an organohydrogenpolysiloxane having at least 2 silicon atom-bonded hydrogen atoms in a molecule, wherein the amount of the silicon atom-bonded hydrogen atoms is 0.3 to 3.0 moles per 1 mole of vinyl groups bonded to the silicon atoms of component (a); (C) a catalyst for hydrosilylation (catalytic amount).

The silicone composition for encapsulating a light-emitting element according to embodiment 2 of the present invention is characterized in that: contains (A)₁)、(A₂) (B) and (C) and the linear expansion coefficient after curing is 10 to 290 x 10^-6/℃；(A₁) Solid at 25 ℃, average unit formula: (SiO)_4/2)_a(ViR₂SiO_1/2)_b(R₃SiO_1/2)_c(wherein Vi represents a vinyl group, R are the same or different substituted or unsubstituted 1-valent hydrocarbon groups other than alkenyl groups, a, b and cA vinyl group-containing organopolysiloxane having a three-dimensional network structure, each of which is a positive number and has a/(a + b + c) of 0.2 to 0.6 and b/(a + b + c) of 0.001 to 0.2); (A)₂) A linear alkenyl group-containing organopolysiloxane having a viscosity of 1 to 100,000 mPas at 25 ℃ and containing a linear alkenyl group relative to (A)₁) Component (A) and (A)₂) The total amount of the components is 10-80 wt%; (B)1 organohydrogenpolysiloxane having at least 2 silicon atom-bonded hydrogen atoms in the molecule and bonded to (A)₁) Vinyl group bonded to silicon atom in component (A)₂) Wherein the total amount of alkenyl groups of silicon atoms is 1 mol and the amount of Si-H bonds is 0.3 to 3 mol; (C) a catalyst for hydrosilylation (catalytic amount).

A light-emitting device according to claim 1 of the present invention is characterized in that: a light-emitting element is encapsulated with a cured product of the silicone composition for encapsulating a light-emitting element of the above-described embodiment 1.

A light-emitting device according to claim 2 of the present invention is characterized in that: a light-emitting element is encapsulated with a cured product of the silicone composition for encapsulating a light-emitting element of the above-described embodiment 2.

The silicone composition for encapsulating a light-emitting element of the present invention has a linear expansion coefficient after curing of 10 to 290 × 10^-6Therefore, a cured product having a good and stable adhesion over a long period of time can be obtained with a reduced residual stress between the cured product and the supporting base material.

Further, according to the light-emitting device of the present invention, since the cured product and the supporting base material have excellent adhesiveness, high reliability can be obtained.

Drawings

FIG. 1: a cross-sectional view showing an example of the light-emitting device of the present invention is shown.

Detailed Description

Next, preferred embodiments of the present invention will be described. The present invention is not limited to the following embodiments.

The silicone composition for encapsulating a light-emitting element according to the embodiment of the present invention contains (a), (B), and (C): (A) average unit formula: (SiO)_4/2)_a(ViR₂SiO_1/2)_b(R₃SiO_1/2)_c(wherein Vi represents vinyl, R is the same or different substituted or unsubstituted 1-valent hydrocarbyl except alkenyl, a, b and c are each a positive number, and a/(a + b + c) is 0.2-0.6, b/(a + b + c) is 0.001-0.2) the organopolysiloxane containing vinyl of three-dimensional network structure shown; (B)1 an organohydrogenpolysiloxane having at least 2 silicon atom-bonded hydrogen atoms in a molecule; (C) a catalyst for hydrosilylation.

(A) Ingredient (b) is the major ingredient of the resulting composition and is the average unit formula: (SiO)_4/2)_a(ViR₂SiO_1/2)_b(R₃SiO_1/2)_cThe illustrated vinyl group-containing organopolysiloxane having a three-dimensional network structure. It is necessary to have 1 or more vinyl groups bonded to silicon atoms in 1 molecule, and 2 or more vinyl groups are particularly preferable.

In the above formula, Vi represents a vinyl group, R represents the same or different substituted or unsubstituted 1-valent hydrocarbon group other than an alkenyl group, and a, b, and c each represent a positive number.

R represents a substituted or unsubstituted 1-valent hydrocarbon group having 1 to 12, preferably 1 to 8, carbon atoms excluding an alkenyl group. Examples of R include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, cyclohexyl and octyl; aryl groups such as phenyl and tolyl; aralkyl groups such as benzyl and phenethyl; and those in which some or all of the hydrogen atoms of these groups are substituted with a halogen atom such as fluorine, chlorine, bromine or the like or a cyano group, for example, chloromethyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group or the like. Methyl and phenyl are particularly preferred.

In the above formula, a, b and c are positive numbers, and a/(a + b + c) is 0.2 to 0.6, and b/(a + b + c) is 0.001 to 0.2.

I.e. SiO_4/2The unit(s) preferably has a ratio of 0.2 to 0.6, particularly 0.2 to 0.4, in the component (A). In such a range, the present composition can be provided with excellent fluidity.

ViR₂SiO_1/2The unit is a crosslinking point of the resulting composition, and preferably has a ratio of 0.001 to 0.2, particularly 0.001 to 0.1 in the component (A). When the amount is less than 0.001, it is difficult to efficiently synthesize a polymer having a vinyl group without imparting appropriate hardness to a cured product. On the other hand, if it exceeds 0.2, the hardness of a cured product obtained by curing the present composition becomes too high, and it becomes difficult to obtain sufficient rubber elasticity.

Such a vinyl group-containing organopolysiloxane having a three-dimensional network structure can be produced by: the compound which is combined to be a source of each unit in the above ratio is produced by a known method, and is co-hydrolyzed in the presence of an acid such as hydrochloric acid.

(A) The components can be used alone or in combination of 2 or more. (A) The component (B) is a solid or a liquid, and particularly preferably a liquid having a viscosity of 1 to 100,000 mPas at 25 ℃.

When the component (A) is a solid at 25 ℃, it is diluted with, for example, a linear alkenyl group-containing organopolysiloxane having a viscosity of 1 to 100,000 mPas at 25 ℃, and preferably 100 to 100,000 mPas at 25 ℃. In this case, the linear expansion coefficient of the present composition after curing is not more than 290X 10^-6/℃。

The alkenyl group of the linear alkenyl group-containing organopolysiloxane may be present only at both ends of the molecular chain, or may be present at both ends of the molecular chain and in the middle of the molecular chain. Typical examples of such a linear alkenyl group-containing organopolysiloxane include, for example, the following general formula.

[ solution 1]

(in the formula, R¹Is the same or different substituted or unsubstituted 1-valent hydrocarbon group having 1 to 10, preferably 1 to 6 carbon atoms except the alkenyl group, X is the alkenyl group, Y independently represents the alkenyl group or R¹N is an integer of 0 or 1 or more, and m is an integer of 0 or 1 or more. )

As R¹Examples thereof include unsubstituted or substituted alkyl groups having 1 to 3 carbon atoms such as methyl, ethyl, propyl, chloromethyl, bromoethyl, 3, 3, 3-trifluoropropyl, cyanoethyl and the like; and unsubstituted or substituted phenyl groups such as phenyl, chlorophenyl, fluorophenyl and the like.

X is an alkenyl group, and examples thereof include alkenyl groups having about 2 to 8 carbon atoms such as a vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group, and cyclohexenyl group, and lower alkenyl groups having 2 to 4 carbon atoms such as a vinyl group and allyl group are more preferable.

Y is alkenyl or R¹Examples of the alkenyl group include the same alkenyl groups as exemplified for X. R¹As described above, the two Y groups as substituents for silicon atoms bonded to both ends of the molecular chain may be the same or different, and are preferably alkenyl groups.

n is 0 or an integer of 1 or more, preferably 0 to 1000, and more preferably 0 to 800. m is an integer of 0 or 1 or more, preferably 0 to 1000. Furthermore, n and m preferably satisfy 1. ltoreq. m + n. ltoreq.1000, and 0. ltoreq. m/(m + n). ltoreq.1; it is particularly preferable that 100. ltoreq. m + n.ltoreq.800 and 0. ltoreq. m/(m + n) 0.5.

The amount of the linear alkenyl group-containing organopolysiloxane is 10 to 80 wt%, preferably 10 to 60 wt%, based on the total amount (100 wt%) of the component (A). When the amount is less than 10% by weight, it is difficult to impart sufficient fluidity to the composition, and when the amount exceeds 80% by weight, it is difficult to adjust the linear expansion coefficient of the cured product to 290X 10^-6Below/° c.

(B) Component (A) functions as a crosslinking agent for curing the composition by a hydrosilylation reaction with component (A). It is necessary to have 2 or more hydrogen atoms (SiH groups) bonded to silicon atoms on average in 1 molecule. Preferably, the number of the SiH groups is 2 to 200, more preferably 3 to 100. The hydrogen atom bonded to the silicon atom may be bonded to a silicon atom at the end of the molecular chain, may be bonded to any silicon atom in the middle of the molecular chain, and may be bonded to both.

As the component (B), an average composition formula can be used: r² _dH_eSiO_[4-(d+e)]/2The substances shown. In the above formula, R²Is a substituted or unsubstituted 1-valent hydrocarbon group having 1 to 12, preferably 1 to 8, carbon atoms excluding an aliphatic unsaturated hydrocarbon group.

As R²Examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, cyclohexyl and octyl; aryl groups such as phenyl and tolyl; aralkyl groups such as benzyl and phenethyl; and those in which a part or all of hydrogen atoms are substituted with a halogen atom such as fluorine, chlorine, bromine or the like or a cyano group, for example, chloromethyl, bromoethyl, trifluoropropyl, cyanoethyl or the like. Among them, a group having 1 to 4 carbon atoms is preferable, and an alkyl group is preferable from the viewpoint of easy synthesis and cost. Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl are preferred. Methyl is particularly preferred.

In the above formula, d and e are positive numbers respectively, and are numbers satisfying d being 0.8-2.2, e being 0.002-1, d + e being 0.8-3; preferably, the number satisfying 1. ltoreq. d.ltoreq.2.2, 0.01. ltoreq. e.ltoreq.1, and 1.8. ltoreq. d + e.ltoreq.2.5.

The molecular structure may be any of linear, branched or cyclic, and preferably contains diorganohydrogensiloxane units and SiO_4/2The unit is a three-dimensional network structure suitably containing a triorganosiloxane unit or a diorganosiloxane unit.

Examples of the component (B) include 1, 1, 3, 3-tetramethyldisiloxane, methylhydrogenocyclopolysiloxane, methylhydrogensiloxane-dimethylsiloxane cyclic copolymer, methylhydrogensiloxane terminated at both ends with trimethylsiloxy groups, dimethylsiloxane-methylhydrogensiloxane copolymer terminated at both ends with trimethylsiloxy groups, and dimethylpolysiloxane terminated at both ends with dimethylhydrogensiloxy groups.

The viscosity at 25 ℃ is preferably 1 to 500 mPas, particularly preferably 1 to 100 mPas.

The amount of component (B) is as follows, based on 1 mole of the total of the vinyl group bonded to the silicon atom in component (a) and the alkenyl group (particularly vinyl group) bonded to the silicon atom in the linear alkenyl group-containing organopolysiloxane: the amount of Si-H bonds is preferably 0.3 to 3 moles, more preferably 0.4 to 2 moles. This is because sufficient crosslinking cannot be obtained when the amount is less than 0.3 mol, and unreacted Si-H bonds remain in a large amount when the amount exceeds 3 mol, thereby making the physical properties unstable.

(C) The component (A) is a catalyst for promoting the hydrosilylation reaction between the vinyl group (A) and the SiH group (B).

Examples of the component (C) include platinum black, chloroplatinum, chloroplatinic acid, a reactant of chloroplatinic acid and a monohydric alcohol, a complex of chloroplatinic acid and an olefin or a vinyl siloxane, a platinum-based catalyst such as platinum bisacetoacetate (platinum bisacetoacetate), a palladium-based catalyst, a rhodium-based catalyst, and the like.

(C) The amount of the component (B) is not particularly limited as long as it is an amount necessary for curing, and may be appropriately adjusted depending on the kinds of the component (a) and the component (B), a desired curing rate, and the like. Usually, the amount of the platinum component may be in the range of 0.01 to 100ppm based on the total weight of the composition to be obtained, and is preferably in the range of 1 to 50ppm from the viewpoint of light transmittance (transparency) of a cured product and cost.

The silicone composition for encapsulating a light-emitting element according to the embodiment of the present invention may further contain a silane coupling agent in order to impart adhesiveness to various supporting substrates, with the components (a) to (C) described above as essential components. Examples of the silane coupling agent include an epoxy group-containing alkoxysilane, an Si — H-containing alkoxysilane, and a vinyl group-containing alkoxysilane. The amount of the silane coupling agent is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the total amount of the components (A) to (C).

In addition, various fillers may be blended for the purpose of improving strength. In view of transparency of the cured product, the average particle diameter is preferably 100nm or less, and particularly preferably 50nm or less. Examples of the filler include a filler having a specific surface area of 150m measured by the BET method²Fumed silica, wet silica, etc. in an amount of at least one gram. The filler may be used as it is, or may be one obtained by surface-treating the filler with a treating agent such as hexamethyldisilazane or the like in advance, or may be one obtained by reacting the filler with the treating agent during production. The amount of the filler is preferably 0.5 to 100 parts by weight per 100 parts by weight of the component (A). When the amount exceeds 100 parts by weight, the viscosity of the composition at the time of non-curing is remarkably increased, and the workability at the time of molding is deteriorated. On the other hand, if the amount is less than 0.5 parts by weight, the properties imparted to the cured product will be insufficient.

Further, a reaction inhibitor such as a compound of phosphorus, nitrogen, or sulfur, or an acetylene compound may be added, and a dye, a pigment, a flame retardancy-imparting agent, a heat-resistant agent, and the like may be added within a range not affecting the transparency of the cured product.

The silicone composition for encapsulating a light-emitting element according to the embodiment of the present invention can be obtained by uniformly mixing the essential components (a) to (C) and the optional components described above with a stirrer. The composition obtained is preferably liquid, and the viscosity at 25 ℃ is preferably 10,000 mPas or less, and particularly preferably about 500 to 5,000 mPas.

The base components (A) to (C) and the optional components are uniformly mixed by a mixer, and curing is carried out at room temperature or under heating, but heating is preferably carried out for rapid curing. The heating temperature is preferably in the range of 50 to 200 ℃. The cured product thus obtained is rubbery, particularly hard rubbery, or resinous with flexibility.

The linear expansion coefficient after curing is 10-290 multiplied by 10^-6The temperature is preferably 10 to 250 x 10^-6V. C. When the linear expansion coefficient after curing is set to a value close to that of a support base material such as ceramics or plastics, the residual stress between the support base material and the cured product can be reduced, and excellent adhesiveness can be obtained over a long period of time.

The silicone composition for encapsulating a light-emitting element of the present invention can be used as an adhesive, potting agent, protective agent, covering agent, encapsulating agent, or underfill agent for electric and electronic devices. Particularly, since the light transmittance is high, the light-emitting device is preferable for a protective agent, a coating agent, an encapsulant, or the like.

Next, a light-emitting device according to an embodiment of the present invention will be described.

The light-emitting device according to the embodiment of the present invention is a light-emitting device encapsulated with a cured product of the above-described silicone composition for encapsulating a light-emitting element. The method of packaging the light emitting element is not particularly limited, and examples thereof include a light emitting device called a surface mount type as shown in fig. 1.

As shown in fig. 1, a light-emitting device 1 includes a light-emitting element 2, a supporting base 3 having an opening, and a cured product 4 of a silicone composition for encapsulating the light-emitting element.

As a method for sealing the light emitting element 2, the light emitting element 2 is fixed by heating with an adhesive such as silver paste on the supporting base 3 having the lead electrode 5 and made of glass fiber reinforced polyphthalamide resin. Next, the light-emitting element 2 and the lead electrode 5 are connected by a bonding wire 6 such as a gold wire. Thereafter, the silicone composition for encapsulating a light-emitting element according to the embodiment of the present invention is cast and encapsulated on the light-emitting element 2, and heated at 50 to 200 ℃ to be cured. Thereby, the light-emitting device 1 can be obtained.

As the light-emitting element, a diode, a transistor, a thin quartz plate rectifier, a solid-state image pickup element, a semiconductor element in a monolithic integrated circuit and a hybrid integrated circuit can be cited.

Examples of the light emitting device include a diode, a Light Emitting Diode (LED), a transistor, a thin quartz rectifier, a photocoupler, a Charge Coupled Device (CCD), a monolithic integrated circuit, an LSI, and a VLSI, and a Light Emitting Diode (LED), a photocoupler, and the like are preferable.

Here, the glass fiber reinforced polyphthalamide resin is used as the support base material, but the present invention is not limited thereto, and various fiber reinforced plastics, ceramics, and the like may be used.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples. In each example, parts are parts by weight, and the viscosity in the examples is a value measured at 25 ℃.

The properties of the cured product of the silicone composition for encapsulating a light-emitting element were measured as follows.

[ coefficient of linear expansion of cured product ]

The silicone composition for encapsulating a light-emitting element was heated at 150 ℃ for 1 hour to prepare a cured product. The linear expansion coefficient of the cured product was measured at 25 to 150 ℃ by TMA (thermo-mechanical analysis).

[ peeling test of cured product ]

0.85g of the silicone composition for encapsulating a light-emitting element was filled in a 10X 45mm glass cell, and cured by heating at 80 ℃ for 2 hours and further at 150 ℃ for 1 hour to prepare a cured product. Thereafter, moisture was absorbed at 60 ℃ and 90% RH for 24 hours, and then the mixture was heated at 260 ℃ for 10 minutes. After cooling, the interface state between the glass cell and the cured product was observed.

Example 1

Mixing and stirring:

formula 1 as a solid at 25 ℃:

[(CH₃)₃SiO_1/2]₅(SiO_4/2)₈[CH₂＝CH(CH₃)₂SiO_1/2]

62 parts by weight of the vinyl group-containing organopolysiloxane (silicon atom-bonded vinyl group content 1.0mmol/g),

formula 2 having a viscosity of 400 mPas:

[(CH₂＝CH)(CH₃)₂SiO_1/2][(CH₃)₂SiO]₁₃₀[(CH₂＝CH)(CH₃)₂SiO_1/2]

38 parts by weight of a dimethylpolysiloxane having both ends of the linear molecular chain blocked with dimethylvinylsiloxy groups (the vinyl content in bonded silicon atoms: 0.2mmol/g),

formula 3 having a viscosity of 20 mPas:

[(CH₃)₂HSiO_1/2]₂(SiO_4/2)

12.4 parts by weight of the organohydrogenpolysiloxane (silicon atom-bonded vinyl group content: 10mmol/g),

CH as silane coupling agent₂＝C(CH₃)COO(CH₂)₃Si(OCH₃)₃And formula 4:

[(CH₃)HSiO]₃(CH₃)₂SiO

1.5 parts by weight of the reaction product of the organosiloxane shown,

a platinum catalyst in an amount of 5ppm in terms of platinum atom,

formula 5:

[(CH₂＝CH)(CH₃)SiO]₄

0.02 part by weight of a reaction inhibitor,

a silicone composition for encapsulating a light-emitting element was prepared.

The properties of the cured product of the silicone composition for encapsulating a light-emitting element were measured. The results are shown in table 1.

Example 2

Uniformly compounding formula 1 as a solid at 25 ℃:

[(CH₃)₃SiO_1/2]5(SiO_4/2)8[CH₂＝CH(CH₃)₂SiO_1/2]

50 parts by weight of the vinyl group-containing organopolysiloxane (the content of vinyl groups bonded to silicon atoms is 1.0mmol/g),

formula 6 having a viscosity of 50 mPas:

[(CH₃)₃SiO_1/2]₁₃(SiO_4/2)₅[CH₂＝CH(CH₃)₂SiO_1/2]

50 parts by weight of the vinyl group-containing organopolysiloxane (silicon atom-bonded vinyl group content: 0.7mmol/g),

formula 3 having a viscosity of 20 mPas:

[(CH₃)₂HSiO_1/2]₂(SiO_4/2)

14.9 parts by weight of an organohydrogenpolysiloxane (silicon atom-bonded vinyl group content: 10mmol/g),

CH as silane coupling agent₂＝C(CH₃)COO(CH₂)₃Si(OCH₃)₃And formula 4: [ (CH)₃)₃HSiO]₃(CH₃)₂1.5 parts by weight of a reaction product of organosiloxane represented by SiO,

a platinum catalyst in an amount of 5ppm in terms of platinum atom,

formula 5:

[(CH₂＝CH)(CH₃)SiO]₄

0.02 part by weight of a reaction inhibitor,

a silicone composition for encapsulating a light-emitting element was prepared.

Example 3

Uniformly compounding formula 1 as a solid at 25 ℃:

[(CH₃)₃SiO_1/2]₅(SiO_4/2)₈[CH₂＝CH(CH₃)₂SiO_1/2]

40 parts by weight of the vinyl group-containing organopolysiloxane (silicon atom-bonded vinyl group content 1.0mmol/g),

formula 7 having a viscosity of 3,000 mPas:

[(CH₂＝CH)(CH₃)₂SiO_1/2][(CH₃)₂SiO]₃₄₀[(CH₂＝CH)(CH₃)₂SiO_1/2]

60 parts by weight of dimethylpolysiloxane having both ends of the linear molecular chain blocked with dimethylvinylsiloxy groups (the vinyl content in terms of silicon atom bonded thereto was 0.08mmol/g),

formula 3 having a viscosity of 20 mPas:

[(CH₃)₂HSiO_1/2]₂(SiO_4/2)

7.9 parts by weight of the organohydrogenpolysiloxane (silicon atom-bonded vinyl group content: 10mmol/g),

CH as silane coupling agent₂＝C(CH₃)COO(CH₂)₃Si(OCH₃)₃And formula 4: [ (CH)₃)HSiO]₃(CH₃)₂1.5 parts by weight of a reaction product of organosiloxane represented by SiO,

a platinum catalyst in an amount of 5ppm in terms of platinum atom,

formula 5:

[(CH₂＝CH)(CH₃)SiO]₄

0.02 part by weight of a reaction inhibitor,

a silicone composition for encapsulating a light-emitting element was prepared.

Comparative example 1

Uniformly compounding formula 1 as a solid at 25 ℃:

[(CH₃)₃SiO_1/2]₅(SiO_4/2)₈[CH₂＝CH(CH₃)₂SiO_1/2]

10 parts by weight of the vinyl group-containing organopolysiloxane (the content of vinyl groups bonded to silicon atoms is 1.0mmol/g),

formula 7 having a viscosity of 3000 mPas:

90 parts by weight of dimethylpolysiloxane having both ends of the linear molecular chain blocked with dimethylvinylsiloxy groups (the vinyl content in terms of silicon atom bonded thereto was 0.08mmol/g),

formula 3 having a viscosity of 20 mPas:

[(CH₃)₂HSiO_1/2]₂(SiO_4/2)

3.0 parts by weight of an organohydrogenpolysiloxane (silicon atom-bonded vinyl group content: 10mmol/g),

a platinum catalyst in an amount of 5ppm in terms of platinum atom,

formula 5:

[(CH₂＝CH)(CH₃)SiO]₄

0.02 part by weight of a reaction inhibitor,

a silicone composition for encapsulating a light-emitting element was prepared.

[ Table 1]

	Example 1	Example 2	Example 3	Comparative example 1
					<Physical Properties>Coefficient of linear expansion (10)^-6/° c) peel test	250○	190○	280○	330×

Note) that the O symbol shows no peeling from the glass colorimetric groove

X symbol shows stripping from glass cuvette

As is clear from Table 1, in comparative example 1, the linear vinyl group-containing organopolysiloxane was added in an amount exceeding 80% by weight based on the total amount of the linear vinyl group-containing organopolysiloxane and the vinyl group-containing organopolysiloxane having a three-dimensional network structure, and therefore the linear expansion coefficient after curing could not be brought to 290X 10^- ⁶Below/° c. On the other hand, the silicone compositions for encapsulating light-emitting elements of examples 1 to 3 can have a linear expansion coefficient after curing of 10 to 290X 10^-6The adhesiveness between the cured product and the glass cuvette can be significantly improved by/° C.

Industrial applicability

The silicone composition for encapsulating a light-emitting element of the present invention can have a linear expansion coefficient after curing close to that of a support base material such as polyphthalamide. This reduces the residual stress between the support base material and the cured product, and can provide excellent adhesion over a long period of time. Therefore, the resin composition can be used as an adhesive, potting agent, protective agent, coating agent, sealing agent, underfill agent, or the like for electrical and electronic applications. In particular, since the light transmittance is high, the compound is preferably used as a protective agent, a coating agent, a sealing agent, or the like for a light-emitting device.

Claims

1. A silicone composition for encapsulating a light-emitting element, characterized in that: comprises

(A) Average unit formula:

(SiO_4/2)_a(ViR₂SiO_1/2)_b(R₃SiO_1/2)_c

disclosed is a vinyl group-containing organopolysiloxane having a three-dimensional network structure with a viscosity of 1-100,000 mPas at 25 ℃, wherein Vi represents a vinyl group, R is an unsubstituted 1-valent hydrocarbon group other than an alkenyl group, or a 1-valent hydrocarbon group in which some or all of the hydrogen atoms of the groups are substituted with halogen atoms or cyano groups, a, b, and c are each a positive number, a/(a + b + c) is a number of 0.2-0.6, b/(a + b + c) is a number of 0.001-0.2,

(B)1 organohydrogenpolysiloxane having at least 2 silicon atom-bonded hydrogen atoms in the molecule, and the amount of the silicon atom-bonded hydrogen atoms is 149/85 to 3.0 moles per 1 mole of vinyl groups bonded to the silicon atoms of component (a), the organohydrogenpolysiloxane having an average composition formula: r² _dH_eSiO_[4-(d+e)]/2And a viscosity at 25 ℃ of 1 to 500 mPas, wherein R is²Is a 1-valent hydrocarbon group having 1 to 12 carbon atoms excluding an aliphatically unsaturated hydrocarbon group, or a 1-valent hydrocarbon group in which a part or all of hydrogen atoms of these groups are substituted with halogen atoms or cyano groups, d and e are each a positive number satisfying 0.8. ltoreq. d.ltoreq.2.2, 0.002. ltoreq. e.ltoreq.1, 0.8. ltoreq. d + e.ltoreq.3, and

(C) a hydrosilylation reaction catalyst in a catalytic amount;

the linear expansion coefficient after curing is 10-290 multiplied by 10^-6/℃。

2. The silicone composition for encapsulating a light-emitting element according to claim 1, wherein: further contains a silane coupling agent as an adhesion imparting component.

3. The silicone composition for encapsulating a light-emitting element according to claim 1, wherein: the viscosity at 25 ℃ is 10,000 mPas or less.

4. A silicone composition for encapsulating a light-emitting element, characterized in that: comprises

(A₁) Solid at 25 ℃, average unit formula:

(SiO_4/2)_a(ViR₂SiO_1/2)_b(R₃SiO_1/2)_c

the vinyl group-containing organopolysiloxane having a three-dimensional network structure is represented by the following formula, wherein Vi represents a vinyl group, R is an unsubstituted 1-valent hydrocarbon group other than an alkenyl group, or a 1-valent hydrocarbon group in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms or cyano groups, a, b, and c are each a positive number, and a/(a + b + c) is a number of 0.2 to 0.6, b/(a + b + c) is a number of 0.001 to 0.2,

(A₂) A linear alkenyl group-containing organopolysiloxane having a viscosity of 1 to 100,000 mPas at 25 ℃, and is based on (A)₁) Component (A) and (A)₂) The total amount of the components is 10 to 80 wt%,

(B)1 organohydrogenpolysiloxane having at least 2 silicon atom-bonded hydrogen atoms in the molecule and bonded to (A)₁) Vinyl group bonded to silicon atom in component (A)₂) Wherein the total of alkenyl groups of silicon atoms is 1 mol, the amount of Si-H bonds is 149/85-3.0 mol, and the organohydrogenpolysiloxane has an average composition formula: r² _dH_eSiO_[4-(d+e)]/2And a viscosity at 25 ℃ of 1 to 500 mPas, wherein R is²Is a 1-valent hydrocarbon group having 1 to 12 carbon atoms excluding an aliphatically unsaturated hydrocarbon group, or a 1-valent hydrocarbon group in which a part or all of hydrogen atoms of these groups are substituted with halogen atoms or cyano groups, d and e are each a positive number satisfying 0.8. ltoreq. d.ltoreq.2.2, 0.002. ltoreq. e.ltoreq.1, 0.8. ltoreq. d + e.ltoreq.3, and

(C) a hydrosilylation reaction catalyst in a catalytic amount;

5. The silicone composition for encapsulating a light-emitting element according to claim 4, wherein: said (A)₂) The component (A) is represented by the following general formula,

[ chemical formula 1]

In the formula, R¹Are the same or different unsubstituted 1-valent hydrocarbon groups having 1 to 10 carbon atoms except the alkenyl group, or part or all of these groupsA 1-valent hydrocarbon group in which a hydrogen atom is substituted with a halogen atom or a cyano group, X is an alkenyl group, Y independently represents an alkenyl group or R¹N is an integer of 0 to 1000, m is an integer of 0 to 1000, n and m satisfy 1. ltoreq. m + n. ltoreq.1000, and 0. ltoreq. m/(m + n). ltoreq.1.

6. The silicone composition for encapsulating a light-emitting element according to claim 4, wherein: with the (A)₂) Component (A) is diluted with₁) Component (A) such that₁) Component (A) and (B)₂) The viscosity of the mixture of the components is 100 to 100,000 mPas at 25 ℃.

7. The silicone composition for encapsulating a light-emitting element according to claim 4, wherein: further contains a silane coupling agent as an adhesion imparting component.

8. The silicone composition for encapsulating a light-emitting element according to claim 4, wherein: the viscosity at 25 ℃ is 10,000 mPas or less.

9. A light emitting device, characterized in that: a light-emitting element is sealed with a cured product of the silicone composition for sealing a light-emitting element according to claim 1.

10. A light emitting device, characterized in that: a light-emitting element is sealed with a cured product of the silicone composition for sealing a light-emitting element according to claim 4.