JP7325375B2 - Thermosetting silicone composition, sheet, and silicone cured product - Google Patents

Description

The present invention relates to thermosetting silicone compositions cured by organic peroxides.

Light-emitting diodes (LEDs) are characterized by low power consumption, long service life, designability, etc., against the background of remarkable improvement in their luminous efficiency. However, the market for general lighting is also rapidly expanding.

Since the emission spectrum of LEDs depends on the semiconductor material forming the LED chip, the emission colors are limited. Therefore, in order to obtain white light for LCD backlights and general illumination using LEDs, it is necessary to arrange phosphors suitable for the respective chips on the LED chips to convert the emission wavelength. Specifically, a method of placing a yellow phosphor on an LED chip that emits blue light, a method of placing red and green phosphors on an LED chip that emits blue light, a method of placing red, green, and blue phosphors on an LED chip that emits ultraviolet light. For example, a method of installing a phosphor of the above has been proposed. Among these methods, the most widely used method is to place a yellow phosphor on a blue LED and a method to place red and green phosphors on a blue LED in terms of the luminous efficiency and cost of the LED chip. .

As one specific method for placing a phosphor on an LED chip, the phosphor is dispersed in an addition-curable silicone composition in which a hydrogen organopolysiloxane and an alkenyl group-containing organopolysiloxane are reacted on the LED chip. A method has been proposed in which the sheet is stuck. However, in this method, the phosphor sheet must be stored at a low temperature so that the addition reaction does not proceed when the phosphor sheet is produced, and a large amount of an addition reaction control agent must be added to the composition. (Patent Documents 1 to 5).

JP 2013-001791 A JP 2013-001792 A JP 2013-138216 A JP 2014-114446 A JP 2014-116598 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermosetting silicone composition that exhibits excellent stability in the uncured state without the addition of a reaction control agent and gives a cured product of high hardness. .

In order to achieve the above problems, in the present invention,
(A) an organopolysiloxane represented by the following average unit formula (1);
( _SiO2 ) _a1 ( ^R13SiO1 _{/ 2} ) _b1 ( ^X1O1 _/2 ) _c1 (1)
(In the formula, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 50 to 99.9% of the total number of R ¹ are methyl groups, and 0. 1 to 50% are alkenyl groups, X ¹ is a hydrogen atom or an alkyl group, a1 is 0.2 to 0.8, b1 is 0.2 to 0.8, c1 is 0 to 0.1 , a1+b1+c1=1.)
(B) an organopolysiloxane represented by the following average unit formula (2);
( _SiO2 ) _a2 ( ^R23SiO1 _{/ 2} ) _b2 ( ^X1O1 _/2 ) _c2 (2)
(wherein R ² is a monovalent hydrocarbon group that may be the same or different and does not contain a substituted or unsubstituted alkenyl group; X ¹ is a hydrogen atom or an alkyl group; a2 is from 0.2 to 0.8, b2 is 0.2 to 0.8, c2 is 0 to 0.1, and a2+b2+c2=1.)
(C) an organopolysiloxane represented by the following average unit formula (3);
(R ³ ₂ SiO) _a3 (R ³ ₃ SiO _1/2 ) _b3 (3)
(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 20% or more of the total number of R ³ is a methyl group, and 0.0001 to 25 % is an alkenyl group, a3 is 0.9980 to 0.9999, b3 is 0.0001 to 0.002, and a3+b3=1.)
(D) a heat-curable silicone composition comprising an organic peroxide (E) a solvent;

The thermosetting silicone composition of the present invention is excellent in stability in the uncured state without the addition of a reaction control agent, and can give a cured product with high hardness.

The amount of component (B) added is preferably 1 to 100 parts by mass per 100 parts by mass of component (A).

The amount of component (C) added is preferably 5 to 100 parts by mass per 100 parts by mass of component (A).

With such a composition, a cured product having more excellent mechanical properties can be obtained.

Further, it is preferable that (F) 20 to 500 parts by mass of the phosphor is contained with respect to a total of 100 parts by mass of the components (A) to (E).

With such a device, it is possible to efficiently wavelength-convert the light emitted from the optical semiconductor element into light of a desired wavelength.

The present invention also provides a sheet formed from the thermosetting silicone composition described above.

Since such a sheet is excellent in stability in an uncured state, it can be applied to a wide range of applications, and is particularly useful for coating the surface of optical semiconductor devices such as LED elements.

Furthermore, the present invention provides a silicone cured product, which is a cured product of the above thermosetting silicone composition.

Such cured silicone products have excellent mechanical properties. In addition, since it is a cured product of a thermosetting silicone composition with excellent stability in an uncured state, it can be applied to a wide range of applications, and is particularly useful for surface coating applications of optical semiconductor devices such as LED elements. becomes.

The thermosetting silicone composition of the present invention has excellent stability in the uncured state without necessarily adding a reaction control agent, and gives a cured product with high hardness. It is useful for surface coating applications of phosphor sheets and LEDs.

As described above, there has been a demand for the development of a thermosetting silicone composition that exhibits excellent stability in the uncured state and gives a cured product of high hardness without the addition of large amounts of reaction control agents.

As a result of intensive studies on the above problems, the present inventors have found that a specific thermosetting silicone composition containing an organic peroxide can solve the above problems, and have completed the present invention.

That is, the present invention
(A) an organopolysiloxane represented by the following average unit formula (1);
( _SiO2 ) _a1 ( ^R13SiO1 _{/ 2} ) _b1 ( ^X1O1 _/2 ) _c1 (1)
(In the formula, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 50 to 99.9% of the total number of R ¹ are methyl groups, and 0. 1 to 50% are alkenyl groups, X ¹ is a hydrogen atom or an alkyl group, a1 is 0.2 to 0.8, b1 is 0.2 to 0.8, c1 is 0 to 0.1 , a1+b1+c1=1.)
(B) an organopolysiloxane represented by the following average unit formula (2);
( _SiO2 ) _a2 ( ^R23SiO1 _{/ 2} ) _b2 ( ^X1O1 _/2 ) _c2 (2)
(wherein R ² is a monovalent hydrocarbon group that may be the same or different and does not contain a substituted or unsubstituted alkenyl group; X ¹ is a hydrogen atom or an alkyl group; a2 is from 0.2 to 0.8, b2 is 0.2 to 0.8, c2 is 0 to 0.1, and a2+b2+c2=1.)
(C) an organopolysiloxane represented by the following average unit formula (3);
(R ³ ₂ SiO) _a3 (R ³ ₃ SiO _1/2 ) _b3 (3)
(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 20% or more of the total number of R ³ is a methyl group, and 0.0001 to 25 % is an alkenyl group, a3 is 0.9980 to 0.9999, b3 is 0.0001 to 0.002, and a3+b3=1.)
A thermosetting silicone composition containing (D) an organic peroxide (E) a solvent.

Although the present invention will be described in detail below, the present invention is not limited thereto.

[Thermosetting silicone composition]
The thermosetting silicone composition of the present invention contains components (A), (B), (C), (D), (E) and optionally component (F) described later.

<(A) Component>
Component (A) is an organopolysiloxane represented by the following average unit formula (1).
( _SiO2 ) _a1 ( ^R13SiO1 _{/ 2} ) _b1 ( ^X1O1 _/2 ) _c1 (1)
(In the formula, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 50 to 99.9% of the total number of R ¹ are methyl groups, and 0. 1 to 50% are alkenyl groups, X ¹ is a hydrogen atom or an alkyl group, a1 is 0.2 to 0.8, b1 is 0.2 to 0.8, c1 is 0 to 0.1 , a1+b1+c1=1.)

R ¹ is a substituted or unsubstituted monovalent hydrocarbon group, and the alkenyl group in R ¹ is exemplified by vinyl, allyl, butenyl, pentenyl, and hexenyl, particularly vinyl. is preferred.

The proportion of the number of alkenyl groups in the total number of R ¹ is 0.1 to 50%, preferably 0.1 to 30%, particularly preferably 0.3 to 20%. If it is less than 0.1%, the curability of the composition will be insufficient, and if it exceeds 50%, the cured product will become brittle.

Silicon-bonded organic groups other than alkenyl groups in R ¹ include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group and heptyl group; Aryl group; aralkyl group such as benzyl group and phenethyl group; halogenated alkyl-substituted or unsubstituted monovalent hydrocarbon group such as chloromethyl group, 3-chloropropyl group and 3,3,3-trifluoropropyl group. An alkyl group having 1 to 3 carbon atoms is preferred, and a methyl group is most preferred from the viewpoint of heat resistance.

The ratio of the number of methyl groups to the total number of R ¹ is 50-99.9%, preferably 60-97%. If it is less than 50 mol %, the heat resistance of the resulting cured product will be insufficient.

X ¹ is a hydrogen atom or an alkyl group, and examples of this alkyl group include the same organic groups as those exemplified for R ¹ , with methyl and ethyl being particularly preferred.

a1 is 0.2 to 0.8, b1 is 0.2 to 0.8, c1 is 0 to 0.1, and a1+b1+c1=1. If a1, b1 and c1 are outside the above ranges, the hardness and/or strength of the resulting cured product will be insufficient.

a1 is preferably 0.3 to 0.7, particularly preferably 0.4 to 0.6, b1 is preferably 0.3 to 0.7, particularly preferably 0.4 to 0.6, c1 is preferably 0 to 0.05.

The molecular weight of component (A) is not limited, but the weight average molecular weight (Mw) determined by GPC measurement (converted to standard polystyrene) using a toluene solvent is preferably 500 to 20,000, more preferably 700 to 15,000. , particularly preferably 1,000 to 10,000.

(A) component may be used individually by 1 type, or may use 2 or more types together.

<(B) Component>
Component (B) is an organopolysiloxane represented by the following average unit formula (2).
( _SiO2 ) _a2 ( ^R23SiO1 _{/ 2} ) _b2 ( ^X1O1 _/2 ) _c2 (2)
(wherein R ² is a monovalent hydrocarbon group that may be the same or different and does not contain a substituted or unsubstituted alkenyl group; X ¹ is a hydrogen atom or an alkyl group; a2 is from 0.2 to 0.8, b2 is 0.2 to 0.8, c2 is 0 to 0.1, and a2+b2+c2=1.)

Examples of the alkenyl-free monovalent hydrocarbon group for R ² include the same silicon-bonded organic groups other than the alkenyl group for R ¹ in component (A). groups are most preferred.

X ¹ is a hydrogen atom or an alkyl group, and examples of this alkyl group include the same organic groups as those exemplified for R ¹ in component (A), with methyl and ethyl being particularly preferred.

a2 is 0.2 to 0.8, b2 is 0.2 to 0.8, c2 is 0 to 0.1, and a2+b2+c2=1. If a2, b2 and c2 are outside the above ranges, the hardness and/or strength of the resulting cured product will be insufficient.

a2 is preferably 0.3 to 0.7, particularly preferably 0.4 to 0.6, b2 is preferably 0.3 to 0.7, particularly preferably 0.4 to 0.6, c2 can be between 0.01 and 0.1, but preferably between 0 and 0.05.

The molecular weight of component (B) is not limited, but the weight average molecular weight (Mw) determined by GPC measurement (converted to standard polystyrene) using a toluene solvent is preferably 500 to 20,000, more preferably 700 to 15,000. , particularly preferably 1,000 to 10,000.

(B) component may be used individually by 1 type, or may use 2 or more types together.

The amount of component (B) is preferably 1 to 100 parts by mass, more preferably 5 to 70 parts by mass, and still more preferably 7 to 50 parts by mass per 100 parts by mass of component (A), from the viewpoint of the hardness of the cured product. part by mass.

<(C) Component>
Component (C) is an organopolysiloxane represented by the following average unit formula (3).
(R ³ ₂ SiO) _a3 (R ³ ₃ SiO _1/2 ) _b3 (3)
(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 20% or more of the total number of R ³ is a methyl group, and 0.0001 to 25 % is an alkenyl group, a3 is 0.9980 to 0.9999, b3 is 0.0001 to 0.002, and a3+b3=1.)

Examples of R ³ include those similar to those of R ¹ in component (A). Preferred examples of the alkenyl group in R ³ include vinyl, allyl, butenyl, pentenyl, and hexenyl. is particularly preferred.

The proportion of alkenyl groups in the total number of R ³ is 0.0001 to 25%, preferably 0.1 to 20%, particularly preferably 0.3 to 20%. If it is less than 0.0001%, the curability of the composition will be insufficient, and if it exceeds 25%, the cured product will become brittle.

Examples of silicon-bonded organic groups other than alkenyl groups in R ³ include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl and heptyl; Aryl group; aralkyl group such as benzyl group and phenethyl group; halogenated alkyl-substituted or unsubstituted monovalent hydrocarbon group such as chloromethyl group, 3-chloropropyl group and 3,3,3-trifluoropropyl group. Among them, a methyl group is most preferable from the viewpoint of heat resistance. If the content of these monovalent hydrocarbon groups in all ^R3 is 20 mol% or more, it is preferable because stable heat resistance can be imparted, and it is more preferably 40 mol% or more.

The ratio of the number of methyl groups to the total number of R ³ is 20 to 99.9999%, preferably 40 to 99.9%. If it is less than 20 mol %, the heat resistance of the resulting cured product will be insufficient.

a3 is 0.9980 to 0.9999, preferably 0.9985 to 0.9999, more preferably 0.9987 to 0.9999. b3 is 0.0001 to 0.002, preferably 0.0001 to 0.0015, more preferably 0.0001 to 0.0013. Also, a3+b3=1.

(C) component may be used individually by 1 type, or may use 2 or more types together.

The amount of component (C) is preferably 5 to 100 parts by mass, more preferably 10 to 70 parts by mass, and still more preferably 30 to 60 parts by mass based on 100 parts by mass of component (A), from the viewpoint of the hardness of the cured product. part by mass.

<(D) Component>
Component (D) is an organic peroxide that cures the thermosetting silicone composition of the present invention by thermally decomposing to generate radicals.

Specific examples of organic peroxides include diacyl peroxides, peroxyesters, dialkyl peroxides, peroxydicarbonates, peroxyketals, hydroperoxides and silyl peroxides.

Examples of diacyl peroxide include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, and succinic peroxide. , benzoyl peroxytoluene and benzoyl peroxide.

Examples of peroxy esters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t -hexyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-bis( 2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethyl Hexanoate, t-butylperoxyisobutyrate, 1,1-bis(t-butylperoxy)cyclohexane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexa nonate, t-butyl peroxylaurate, 2,5-dimethyl-2,5-bis(m-toluoylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl Monocarbonates, t-hexylperoxybenzoate, t-butylperoxyacetate and bis(t-butylperoxy)hexahydroterephthalate.

Dialkyl peroxides include, for example, α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane and t - butyl cumyl peroxide.

Examples of peroxydicarbonates include di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di-2-ethoxymethoxyperoxydicarbonate, Bis(2-ethylhexylperoxy)dicarbonate, dimethoxybutylperoxydicarbonate and bis(3-methyl-3-methoxybutylperoxy)dicarbonate.

Examples of peroxyketals include 1,6-bis(t-butylperoxycarbonyloxy)hexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1- bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-(t-butylperoxy)cyclododecane and 2,2- Bis(t-butylperoxy)decane can be mentioned.

Hydroperoxides include, for example, diisopropylbenzene hydroperoxide and cumene hydroperoxide.

Silyl peroxides include, for example, t-butyltrimethylsilyl peroxide, bis(t-butyl)dimethylsilyl peroxide, t-butyltrivinylsilyl peroxide, bis(t-butyl)divinylsilyl peroxide, tris(t- butyl)vinylsilyl peroxide, t-butyltriallylsilyl peroxide, bis(t-butyl)diallylsilyl peroxide and tris(t-butyl)allylsilyl peroxide.

As component (D), an organic peroxide having a half-life of 1 hour or more at 100° C. is preferable from the viewpoint of stability in an uncured state.

Component (D) may be used singly or in combination of two or more.

The amount of component (D) may be an effective amount (that is, a so-called catalytic amount), but is preferably 0.01 to 10 parts by mass, particularly 0.1 to 5 parts by mass, per 100 parts by mass of component (A). is preferably blended.

<(E) component>
The solvent of the component (E) is not particularly limited as long as it dissolves the components (A) to (D) constituting the present composition, and known organic solvents can be used. Examples of the solvent include aromatic hydrocarbon solvents such as xylene, toluene and benzene; aliphatic hydrocarbon solvents such as heptane and hexane; halogenated hydrocarbon solvents such as trichlorethylene, perchlorethylene and methylene chloride; Examples include ester solvents such as ethyl acetate, ketone solvents such as methyl isobutyl ketone and methyl ethyl ketone, alcohol solvents such as ethanol, isopropanol and butanol, ligroin, cyclohexanone, diethyl ether, rubber volatile oils, and silicone solvents. Among them, toluene, heptane and ethyl acetate are preferably used.

Component (E) may be used alone or as a mixed solvent in combination of two or more depending on the evaporation rate of the thermosetting silicone composition of the present invention during coating.

The amount of component (E) is not particularly limited, but from the viewpoint of workability during coating work, it is preferably 50 to 200 parts by mass, more preferably 50 to 200 parts by mass per 100 parts by mass of components (A) to (D). 100 to 150 parts by mass.

<(F) Component>
The thermosetting silicone composition of the present invention may contain (F) a phosphor. By mixing and dispersing the phosphor in the thermosetting silicone composition, it is possible to efficiently convert the light emitted from the optical semiconductor element into light of a desired wavelength.

The phosphor absorbs blue light, violet light, and ultraviolet light emitted from the optical semiconductor element and converts the wavelength to red, orange, yellow, green, and blue regions of wavelengths different from the light emitted from the optical semiconductor element. It emits light with a wavelength of As a result, part of the light emitted from the optical semiconductor element and part of the light emitted from the phosphor are mixed to obtain a multicolor optical semiconductor device including white.

The phosphors described above include various phosphors such as a phosphor emitting green light, a phosphor emitting blue light, a phosphor emitting yellow light, and a phosphor emitting red light. Specific phosphors used in the present invention include known phosphors such as organic phosphors, inorganic phosphors, fluorescent pigments, and fluorescent dyes. Examples of organic phosphors include allylsulfamide/melamine formaldehyde co-condensation dyes and perylene phosphors. Perylene phosphors are preferably used because they can be used for a long period of time. Inorganic phosphors are examples of phosphors that are particularly preferably used in the present invention. Inorganic phosphors used in the present invention are described below, but are not limited thereto.

Examples of phosphors that emit green light include SrAl ₂ O ₄ :Eu, Y ₂ SiO ₅ :Ce, Tb, MgAl ₁₁ O ₁₉ :Ce, Tb, Sr ₇ Al ₁₂ O ₂₅ :Eu, (Mg, Ca, Sr , Ba) Ga ₂ S ₄ :Eu and the like.

Examples of phosphors that emit blue light include Sr ₅ (PO ₄ ) ₃ Cl:Eu, (SrCaBa) ₅ (PO ₄ ) ₃ Cl:Eu, (BaCa) ₅ (PO ₄ ) ₃ Cl:Eu, (Mg, at least one of Ca, Sr and Ba) ₂ B ₅ O ₉ Cl: Eu, Mn, (at least one of Mg, Ca, Sr and Ba) (PO ₄ ) _{6 Cl2} : Eu, Mn, etc. be done.

Yttrium-aluminum oxide phosphors activated with at least cerium, yttrium-gadolinium-aluminum oxide phosphors activated with at least cerium, and yttrium-aluminum activated with at least cerium as phosphors emitting green to yellow light - Garnet oxide phosphors and yttrium-gallium-aluminum oxide phosphors activated at least with cerium (so-called YAG-based phosphors). Specifically, Ln ₃ M ₅ O ₁₂ :A (Ln is at least one selected from Y, Gd, and La. M includes at least one of Al and Ca. A is a lanthanide-based ), (Y _1-x Ga _x ) ₃ (Al _1-y Ga _y ) ₅ O ₁₂ :A (A is at least one selected from Ce, Tb, Pr, Sm, Eu, Dy, Ho 0<x<0.5, 0<y<0.5.) can be used.

Examples of phosphors that emit red light include Y ₂ O ₂ S:Eu, La ₂ O ₂ S:Eu, Y ₂ O ₃ :Eu, and Gd ₂ O ₂ S:Eu.

In addition, phosphors that emit _light corresponding to blue _LEDs include _Y3 (Al,Ga) _5O12 :Ce _{, (} Y,Gd) _3Al5O12 :Ce, _{Lu3Al5O12 :} Ce, Y _YAG -based phosphors such as _3Al5O12 :Ce, _TAG - _based phosphors such as _Tb3Al5O12 :Ce _, ( _Ba ,Sr) _2SiO4 : _{Eu -} based phosphors and _{Ca3Sc2Si3O 12} : Ce-based phosphor, silicate-based phosphor such as (Sr, Ba, Mg) ₂ SiO ₄ :Eu, (Ca, Sr) ₂ Si ₅ N ₈ : Eu, (Ca, Sr) AlSiN ₃ : Eu, CaSiAlN ₃ : Nitride phosphors such as Eu, Cax(Si, Al) ₁₂ (O, N) ₁₆ : Oxynitride phosphors such as Eu, and (Ba, Sr, Ca)Si ₂ O ₂ N ₂ : _Eu phosphor, _{Ca8MgSi4O16Cl2} :Eu phosphor _{, SrAl2O4 : Eu , Sr4Al14O25} :Eu and the _like .

Among these, YAG-based phosphors, TAG-based phosphors, and silicate-based phosphors are preferably used in terms of luminous efficiency and brightness.

In addition to the above, known phosphors can be used depending on the application and the intended emission color.

The particle size of the phosphor is not particularly limited, but _D50 is preferably 0.05 μm or more, more preferably 3 μm or more. Also, _D50 is preferably 30 μm or less, more preferably 20 μm or less. Here, _D50 refers to the particle diameter at which 50% of the passage from the small particle side is integrated in the volume-based particle size distribution obtained by the laser diffraction scattering particle size distribution measurement method. When _D50 is within the above range, the phosphor has good dispersibility in the thermosetting silicone composition (for example, the resin composition for wafer-level optical semiconductor devices) of the present invention, and stable light emission can be obtained.

You may use the said fluorescent substance in mixture of 1 type, or 2 or more types.

The content of component (F) is preferably 20 to 500 parts by mass, more preferably 50 to 400 parts by mass or more, based on the total of 100 parts by mass of components (A) to (E). More preferably, it is 300 parts by mass. By setting the phosphor content within the above range, the light conversion efficiency can be enhanced.

The thermosetting silicone composition of the present invention is particularly preferably used as a phosphor sheet for coating the surface of LEDs by blending a phosphor. At this time, by setting the content of the phosphor in the phosphor sheet within the above range, it is possible to obtain an LED light emitting device exhibiting excellent performance.

<Optional component>
The thermosetting silicone composition of the present invention may contain, in addition to the above components (A) to (F), adhesion improvers exemplified below.

As the adhesion improver, an organopolysiloxane or organosilane compound having at least one, preferably two or more silicon-bonded alkoxy groups in one molecule, or an organopolysiloxane or organosilane compound containing a group having an epoxy moiety, or Organosilane compounds are preferred.

The alkoxy group is exemplified by methoxy, ethoxy, propoxy, butoxy, and methoxyethoxy, with methoxy being particularly preferred. In addition, the groups other than the alkoxy group bonded to the silicon atom of the organosilicon compound include the above alkyl group, the above alkenyl group, the above aryl group, the above aralkyl group, the above halogenated alkyl group, etc., which are exemplified for R ¹ and the like. substituted or unsubstituted monovalent hydrocarbon group; acrylic group-containing monovalent organic group such as 3-methacryloxypropyl group; and hydrogen atom. Specific examples include silane coupling agents such as (meth)acrylic group-containing silane coupling agents and partial hydrolysis condensates thereof (oligomers of silane coupling agents). More specifically, silane compounds such as 3-methacryloxypropyltrimethoxysilane; siloxane compounds having at least one silicon-bonded alkenyl group or silicon-bonded hydrogen atom and at least one silicon-bonded alkoxy group in one molecule. , a mixture of a silane compound or a siloxane compound having at least one silicon-bonded alkoxy group and a siloxane compound having at least one silicon-bonded hydroxy group and at least one silicon-bonded alkenyl group per molecule, methyl polysilicate, ethyl Examples include polysilicates and epoxy group-containing ethyl polysilicates.

The group having an epoxy moiety includes glycidoxyalkyl groups such as 3-glycidoxypropyl group and 4-glycidoxybutyl group; 2-(3,4-epoxycyclohexyl)ethyl group, 3-(3,4 -epoxycyclohexylalkyl groups such as propyl groups; epoxy group-containing monovalent organic groups such as oxiranylalkyl groups such as 4-oxiranylbutyl groups and 8-oxiranyloctyl groups.

The adhesion improver is preferably a low-viscosity liquid, and although its viscosity is not limited, it is preferably in the range of 1 to 500 mPa·s at 23°C.

Although the content of the adhesion improver is not limited, it is preferably 0.01 to 10 parts by weight per 100 parts by weight of component (A).

The thermosetting silicone composition of the present invention may also contain inorganic fillers other than component (F), such as fumed silica, fused quartz glass, alumina, and zinc oxide; organic resin fine powder such as polymethacrylate resin; , dyes, pigments, flame retardant agents, and the like.

When inorganic fillers other than component (F) are used, the blending amount is preferably 5 to 500 parts by mass, more preferably 10 to 200 parts by mass, per 100 parts by mass of component (A). Within such a range, the composition of the present invention has better fluidity.

The viscosity at 25° C. of the thermosetting silicone composition of the present invention is preferably 10 to 5,000 mPa·s, more preferably 20 to 2,000 mPa·s. Within such a range, the resulting composition tends to have good workability and handleability, and is less prone to entrainment of bubbles and air during molding and curing. In addition, in this invention, a viscosity can be made into the value when it measures with a rotational viscometer.

The viscosity of the thermosetting silicone composition of the present invention is adjusted by the blending amount and viscosity of components (A) to (E) and other components, and the blending amount and average particle size of component (F).

The thermosetting silicone composition of the present invention has excellent stability in the uncured state without the addition of a reaction control agent, and gives a cured product with high hardness, so it can be applied to a wide range of applications. It is particularly useful for coating the surface of optical semiconductor devices such as LED elements. However, as long as the thermosetting silicone composition of the present invention contains components (A) to (E), it may contain a reaction control agent depending on the purpose.

[Sheet]
The present invention provides a sheet formed from the thermosetting silicone composition described above. The sheet may be a cured composition or an uncured composition, but the uncured composition is preferred. The sheet of the present invention is particularly useful for coating the surface of optical semiconductor devices such as LED elements.

The method for producing the sheet of the present invention is not particularly limited. For example, a sheet (uncured sheet) can be obtained by heating the thermosetting silicone composition of the present invention at a temperature lower than the temperature at which the composition cures (E) to volatilize the solvent.

[Silicone cured product]
A cured product can be obtained by molding and curing the thermosetting silicone composition of the present invention. As a molding method, conventionally used methods such as an injection molding method and a transfer molding method can be applied. Furthermore, since the thermosetting silicone composition of the present invention has high fluidity, it can be molded by a dispensing method, a potting method, or various coating methods.

The heat-curable silicone composition of the present invention is cured by heating, and it is preferable to heat the composition at a high temperature in order to cure it quickly. The curing conditions vary depending on the shape of the molded product, the curing method, etc., and are not particularly limited, but the curing temperature is preferably in the range of 130 to 200° C., and the curing time is preferably 1 minute to 24 hours, more preferably. 5 minutes to 5 hours.

The cured silicone product of the present invention preferably has a Shore D hardness of 20 or more, more preferably 30 to 70.

EXAMPLES The present invention will be specifically described below using Examples and Comparative Examples, but the present invention is not limited to these.

[Example 1]
Structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.40 ((CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 ) _0.05 (A) 100 parts by mass of component, 40 parts by mass of component (B) represented by structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.45 , structural unit ratio ((CH ₃ ) ₂ SiO ) _0.9996 ((CH ₂ ═CH) (CH ₃ ) ₂ SiO _1/2 ) 50 parts by mass of component (C) represented by _0.0004 , and an organic peroxide (Kyaku Akzo Co., Ltd.) as component (D). A thermosetting silicone composition was prepared by mixing 3.5 parts by weight of Kayaren 6-70) manufactured by the company and 200 parts by weight of toluene as component (E).

[Example 2]
150 parts by mass of YAG phosphor was mixed with 100 parts by mass of the thermosetting silicone composition obtained in Example 1 to prepare a phosphor-containing thermosetting silicone composition.

[Example 3]
Structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.40 ((CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 ) _0.05 (A) 100 parts by mass of component, 25 parts by mass of component (B) represented by structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.45 , structural unit ratio ((CH ₃ ) ₂ SiO ) _0.9996 ((CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 ) 40 parts by mass of component (C) represented by _0.0004 , organic peroxide (Kayaku Akzo Co., Ltd.) as component (D) A thermosetting silicone composition was prepared by mixing 3 parts by weight of Kayalen 6-70) manufactured by Kayaren Co., Ltd. and 170 parts by weight of toluene as component (E).

[Example 4]
150 parts by mass of YAG phosphor was mixed with 100 parts by mass of the thermosetting silicone composition obtained in Example 3 to prepare a phosphor-containing thermosetting silicone composition.

[Comparative Example 1]
Structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.40 ((CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 ) _0.05 (A) 100 parts by mass of component, 40 parts by mass of component (B) represented by structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.45 , structural unit ratio ((CH ₃ ) ₂ SiO ) _0.9996 ((CH ₂ ═CH) (CH ₃ ) ₂ SiO _1/2 ) 50 parts by mass of component (C) represented by _0.0004 , platinum 1,3-divinyl-1,1,3,3 - A tetramethyldisiloxane complex (the amount of platinum metal in the complex is 10 ppm by mass with respect to the total of components (A) to (C)), and an organohydrogenpolysiloxane 7 represented by the following formula (4) Parts by weight, 0.2 parts by weight of ethynylcyclohexanol as a reaction controller, and 200 parts by weight of toluene as component (E) were mixed to prepare a thermosetting silicone composition.

[Comparative Example 2]
100 parts by mass of component (B) represented by structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.45 , structural unit ratio ((CH ₃ ) ₂ SiO) _0.9996 ( 50 parts by mass of component (C) represented by (CH ₂ ═CH)(CH ₃ ) ₂ SiO _1/2 ) _0.0004 , and an organic peroxide (Kayalen 6-70 manufactured by Kayaku Akzo Co., Ltd.) as component (D). ) and 150 parts by mass of toluene as component (E) were mixed to prepare a thermosetting silicone composition.

[Comparative Example 3]
Structural unit ratio (SiO ₂ ) _0.55 ((CH ₃ ) ₃ SiO _1/2 ) _0.40 ((CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 ) _0.05 (A) component 100 parts by mass, structural unit ratio ((CH ₃ ) ₂ SiO) _0.9996 ((CH ₂ =CH) (CH ₃ ) ₂ SiO _1/2 ) _0.0004 (C) component 50 parts by mass, A heat-curable silicone composition was prepared by mixing 3 parts by weight of an organic peroxide (Kayalen 6-70 manufactured by Kayaku Akzo Co., Ltd.) as component (D) and 150 parts by weight of toluene as component (E).

The compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were poured into a frame made of Teflon (registered trademark) with a thickness of 2 mm, and heated at 60°C for 1 hour, 80°C for 1 hour, and 100°C for 1 hour in that order. The solvent was volatilized by heating to produce a sheet. The obtained sheet was subjected to the following tests (1) and (2) to confirm physical properties. Table 1 shows the results.

Test (1): After the sheet was exposed to 120°C for 10 minutes, it was checked whether it was soluble in toluene.
Test (2): The sheet was cured at 150° C. for 3 hours, the appearance of the resulting cured product was observed, and the hardness was measured.
- Appearance: The presence or absence of cracks was visually observed.
No cracks (○), cracks (×)
- Hardness: Measured with a durometer type D type hardness tester manufactured by Ueshima Seisakusho Co., Ltd.

As shown in Table 1, the sheets obtained in Examples 1 to 4 were soluble in toluene even after heating at 120° C. for 10 minutes, and remained uncured. It was also shown that a hardened product with high hardness can be obtained by heating at 150° C. for 3 hours.

On the other hand, in Comparative Example 1, which is a composition curable by hydrosilylation, the composition was cured by heating at 120° C. for 10 minutes even in the presence of the reaction inhibitor, and the uncured state could not be maintained. In Comparative Example 2, which did not contain the component (A), the hardness of the cured product was remarkably lowered, and in Comparative Example 3, which did not contain the component (B), cracks occurred in the cured product.

In addition, this invention is not limited to the said embodiment. The above-described embodiment is an example, and any device having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect is the present invention. included in the technical scope of

Claims (4)

(A) an organopolysiloxane represented by the following average unit formula (1);
( _SiO2 ) _a1 ( ^R13SiO1 _{/ 2} ) _b1 ( ^X1O1 _/2 ) _c1 (1)
(In the formula, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 50 to 99.9% of the total number of R ¹ are methyl groups, and 0. 1 to 50% are alkenyl groups, X ¹ is a hydrogen atom or an alkyl group, a1 is 0.2 to 0.8, b1 is 0.2 to 0.8, c1 is 0 to 0.1 , a1+b1+c1=1.)
(B) an organopolysiloxane represented by the following average unit formula (2);
( _SiO2 ) _a2 ( ^R23SiO1 _{/ 2} ) _b2 ( ^X1O1 _/2 ) _c2 (2)
(wherein R ² is a monovalent hydrocarbon group that may be the same or different and does not contain a substituted or unsubstituted alkenyl group; X ¹ is a hydrogen atom or an alkyl group; a2 is from 0.2 to 0.8, b2 is 0.2 to 0.8, c2 is 0 to 0.1, and a2+b2+c2=1.)
(C) an organopolysiloxane represented by the following average unit formula (3);
(R ³ ₂ SiO) _a3 (R ³ ₃ SiO _1/2 ) _b3 (3)
(In the formula, R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, 20% or more of the total number of R ³ is a methyl group, and 0.0001 to 25 % is an alkenyl group, a3 is 0.9980 to 0.9999, b3 is 0.0001 to 0.002, and a3+b3=1.)
(D) A thermosetting silicone composition containing an organic peroxide (E) solvent having a half-life of 1 hour or longer at 100°C ,
The amount of component (B) added is 1 to 100 parts by mass with respect to 100 parts by mass of component (A),
The amount of component (C) added is 5 to 100 parts by mass with respect to 100 parts by mass of component (A), and
A thermosetting silicone composition, wherein component (D) is added in an amount of 0.01 to 10 parts by mass per 100 parts by mass of component (A) . 2. The thermosetting silicone composition according to claim 1, containing 20 to 500 parts by weight of (F) phosphor with respect to a total of 100 parts by weight of components (A) to (E). A sheet formed from the thermosetting silicone composition according to claim 1 or 2 . A cured silicone product which is a cured product of the thermosetting silicone composition according to claim 1 or 2 .