JP2021001296A - Radical curable silicone composition and cured product - Google Patents

Abstract

To provide a radical curable silicone composition that has quantum dots dispersed therein and can be cured at low temperature.SOLUTION: A radical curable silicone composition contains (A) a linear organopolysiloxane represented by the formula (1) and (B) a polymerization initiator. (R1R22SiO1/2)a(R3R22SiO1/2)b(R22SiO2/2)c(R3R2SiO2/2)d(R1R2SiO2/2)e (1), where R1 is a C2-8 alkenyl group, R2 is a C1-8 alkyl group or a C6-12 aryl group, 10 mol% or more of all the R2 is aryl groups, R3 is a group represented by the formula (2). a-e each represent a number of 0 or more and satisfying a+b>0, b+d>0, a+b+c+d+e=1. In the formula (2), R4 is a C1-8 bivalent hydrocarbon group, R5 is an H atom, a C1-8 alkyl group, or a C6-12 aryl group. * is a bond to a silicon atom).SELECTED DRAWING: None

Description

The present invention relates to a radical curable silicone composition and a cured product thereof.

In recent years, with the spread of personal computers, televisions, smartphones, etc., the demand for image display devices has been increasing. LEDs (light emitting diodes) are widely used as backlights of such image display devices. Since the emission spectrum of an LED depends on the semiconductor material forming the LED chip, its emission color is limited. Therefore, in order to obtain white light for a backlight of a liquid crystal display or general lighting using an LED, it is necessary to arrange a phosphor suitable for each chip on the LED chip and convert the emission wavelength. Specifically, the method of placing a yellow phosphor on an LED chip that emits blue light and the method of placing red and green phosphors on an LED chip that emits blue light are currently most widely adopted.

When an LED is used as the backlight of a display, the color reproduction range of the display widens as the half width of the emission spectrum of the phosphor narrows. However, the half width of the emission spectrum of the phosphor is relatively wide. Therefore, when an LED using a yellow phosphor is used as a backlight of a display, the color reproduction range is not sufficient.

In recent years, quantum dots have been attracting attention as a wavelength conversion material. Since the bandgap of quantum dots can be adjusted according to the particle size, the half-value width of the emission spectrum can be narrowed by making the particle size uniform, and light with excellent distributed color purity can be generated, making it suitable for backlight applications. Suitable.

Such quantum dots are dispersed in a matrix material and used as a sealing material or a filter. Acrylic resins, epoxy resins, and the like are used as the matrix, and such resins have problems of durability and crack resistance (Patent Documents 1 and 2).
Further, since the heat resistance of the quantum dots themselves is low, a matrix material that can be cured at a low temperature is required. It is also necessary for the quantum dots to be uniformly dispersed in the matrix without agglomeration.

Japanese Unexamined Patent Publication No. 2018-13724 Special Table 2016-536641

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radical-curable silicone composition in which quantum dots are dispersed and curable at a low temperature.

（式中、Ｒ^４はそれぞれ独立に置換または非置換の炭素原子数１〜８の二価炭化水素基であり、Ｒ^５は水素原子、置換または非置換の炭素原子数１〜８のアルキル基、置換または非置換の炭素原子数６〜１２のアリール基のいずれかであり、＊は隣接ケイ素原子との結合を表す。）、
及び、
（Ｂ）重合開始剤
を含有するものであることを特徴とするラジカル硬化型シリコーン組成物を提供する。 In order to solve the above problems, the present invention
(A) Linear organopolysiloxane represented by the following formula (1) (R ¹ R ² ₂ SiO _1/2 ) _a (R ³ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO _{2 / 2} ) _c (R ³ R ² SiO _2/2 ) _d (R ¹ R ² SiO _2/2 ) _e (1)
(In the formula, R ¹ is an alkenyl group having 2 to 8 carbon atoms, R ² is an alkyl group having 1 to 8 carbon atoms independently substituted or unsubstituted, or 6 to 8 substituted or unsubstituted carbon atoms. There are 12 aryl groups, except that at least 10 mol% of the total R ² is the aryl group, R ³ is a group represented by the following formula (2), and a, b, c, d and e are each. , A ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, e ≧ 0, and a + b> 0, b + d> 0, a + b + c + d + e = 1.

(In the formula, R ⁴ is an independently substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms, and R ⁵ is a hydrogen atom, substituted or unsubstituted alkyl group having 1 to 8 carbon atoms. , Either a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and * represents a bond with an adjacent silicon atom.),
as well as,
(B) Provided is a radical curable silicone composition characterized by containing a polymerization initiator.

The radical-curable silicone composition of the present invention can disperse quantum dots well, and can be cured at a low temperature by radical curing.

The radical-curable silicone composition of the present invention preferably further contains (C) quantum dots.

With such a radical-curable silicone composition, the quantum dots are uniformly dispersed without agglutination in the matrix, so that an excellent wavelength conversion material can be obtained.

Further, in the radical curable silicone composition of the present invention, it is more preferable that each of the R ² is independently a methyl group or a phenyl group.

Such a linear organopolysiloxane (component (A)) having R ² is industrially easily available.

In the radical curable silicone composition of the present invention, the polymerization initiator is preferably an organic peroxide or a photopolymerization initiator.

Such a polymerization initiator can cure the composition of the present invention more effectively.

In this case, it is more preferable that the organic peroxide has a 10-hour half-life temperature of 50 to 150 ° C.

Such an organic peroxide is excellent in storage stability and curability controllability of the composition, and when it contains (C) quantum dots, it can be cured at a low temperature. The thermal effect on the quantum dots can be suppressed.

The present invention also provides a cured silicone composition, which is a cured product of the radical curable silicone composition.

Since the cured silicone product of the present invention has excellent transparency and good hardness, it is useful for applications such as display backlights and lighting. Further, when the cured product further contains (C) quantum dots, the quantum dots are uniformly dispersed without agglutination in the matrix, so that they are excellent as a wavelength conversion material, and are excellent as a sealing material or a sealing material. It is useful for applications such as filters.

The radical-curable silicone composition of the present invention has good dispersibility of quantum dots and can be cured at a low temperature by radical curing, so that it is useful for applications such as display backlights and lighting.

As a result of diligent studies to achieve the above object, the present inventors have found that the above problems can be solved if the silicone resin composition containing the components (A) and (B) described later is used, and complete the present invention. It was.

（式中、Ｒ^４はそれぞれ独立に置換または非置換の炭素原子数１〜８の二価炭化水素基であり、Ｒ^５は水素原子、置換または非置換の炭素原子数１〜８のアルキル基、置換または非置換の炭素原子数６〜１２のアリール基のいずれかであり、＊は隣接ケイ素原子との結合を表す。）、
及び、
（Ｂ）重合開始剤
を含有するものであることを特徴とするラジカル硬化型シリコーン組成物である。 That is, the present invention is a radical curable silicone composition.
(A) Linear organopolysiloxane represented by the following formula (1) (R ¹ R ² ₂ SiO _1/2 ) _a (R ³ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO _{2 / 2} ) _c (R ³ R ² SiO _2/2 ) _d (R ¹ R ² SiO _2/2 ) _e (1)
(In the formula, R ¹ is an alkenyl group having 2 to 8 carbon atoms, R ² is an alkyl group having 1 to 8 carbon atoms independently substituted or unsubstituted, or 6 to 8 substituted or unsubstituted carbon atoms. There are 12 aryl groups, except that at least 10 mol% of the total R ² is the aryl group, R ³ is a group represented by the following formula (2), and a, b, c, d and e are each. , A ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, e ≧ 0, and a + b> 0, b + d> 0, a + b + c + d + e = 1.

(In the formula, R ⁴ is an independently substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms, and R ⁵ is a hydrogen atom, substituted or unsubstituted alkyl group having 1 to 8 carbon atoms. , Either a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and * represents a bond with an adjacent silicon atom.),
as well as,
(B) A radical-curable silicone composition containing a polymerization initiator.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[Radical curable silicone composition]
The radical curable silicone composition of the present invention contains the components (A) and (B) described later as essential components. This composition may further contain any component other than the essential component, if necessary.
Hereinafter, each component will be described in detail.

（式中、Ｒ^４はそれぞれ独立に置換または非置換の炭素原子数１〜８の二価炭化水素基であり、Ｒ^５は水素原子、置換または非置換の炭素原子数１〜８のアルキル基、置換または非置換の炭素原子数６〜１２のアリール基のいずれかであり、＊は隣接ケイ素原子との結合を表す。）、 [(A) component]
The component (A) is a linear organopolysiloxane represented by the following formula (1).
(R ¹ R ² ₂ SiO _1/2 ) _a (R ³ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO _2/2 ) _c (R ³ R ² SiO _2/2 ) _d (R ¹ R ²⁾ SiO _2/2 ) _e (1)
(In the formula, R ¹ is an alkenyl group having 2 to 8 carbon atoms, R ² is an alkyl group having 1 to 8 carbon atoms independently substituted or unsubstituted, or 6 to 8 substituted or unsubstituted carbon atoms. There are 12 aryl groups, except that at least 10 mol% of the total R ² is the aryl group, R ³ is a group represented by the following formula (2), and a, b, c, d and e are each. , A ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, e ≧ 0, and a + b> 0, b + d> 0, a + b + c + d + e = 1.

(In the formula, R ⁴ is an independently substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms, and R ⁵ is a hydrogen atom, substituted or unsubstituted alkyl group having 1 to 8 carbon atoms. , Either a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and * represents a bond with an adjacent silicon atom.),

In the above formula (1), examples of the alkenyl group having 2 to 8 carbon atoms represented by R ¹ include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, an octenyl group and the like, and in particular, a vinyl group. Is preferable. The hydrogen atom in these groups may be further substituted with an arbitrary substituent (halogen atom or the like).

Examples of the alkyl group having 1 to 8 carbon atoms represented by R ^2, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group and the like, especially Methyl groups are preferred. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group and a naphthyl group, and a phenyl group is particularly preferable. The hydrogen atom in these groups may be further substituted with an arbitrary substituent (halogen atom or the like).
At least 10 mol% or more of the total R ² is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, preferably 15 mol% or more. If the aryl group is less than 10 mol% of the total R ² , the dispersibility of the quantum dots becomes poor, and the transparency of the composition and its cured product may be impaired.

It is particularly preferable that R ² is independently a methyl group or a phenyl group. Such a linear organopolysiloxane (component (A)) having R ² is industrially easily available.

The divalent hydrocarbon radical of a substituted or unsubstituted 1-8 carbon atoms represented by R ^4, a methylene group, an ethylene group, a propylene group, a trimethylene group, a pentamethylene group, hexamethylene group, heptamethylene group, A linear, branched or cyclic alkylene group having 1 to 8 carbon atoms such as an octamethylene group, preferably one having 1 to 4 carbon atoms, particularly a methylene group, an ethylene group, a propylene group and a trimethylene group. preferable. The hydrogen atom in these groups may be further substituted with an arbitrary substituent (halogen atom or the like).

R ⁵ is any of a hydrogen atom, an alkyl group having 1 to 8 substituted or unsubstituted carbon atoms, and an aryl group having 6 to 12 substituted or unsubstituted carbon atoms, and may be a hydrogen atom or a methyl group. preferable.

The linear organopolysiloxane represented by the above formula (1) is in units of (R ¹ R ² ₂ SiO _1/2 ) (also referred to as “a unit”; the same applies hereinafter), (R ³ R ² ₂ SiO). _1/2) units (b _{^{units), (R 2 2 SiO 2/2}} ) units (c _{^{unit), (R 3 R 2 SiO}} 2/2) units (d _{^{units), (R 1 R 2 SiO}} 2/2 ) Units (e units), and the constituent ratios a, b, c, d, and e of each unit are a ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, and e ≧ 0, respectively. , A + b> 0, b + d> 0, a + b + c + d + e = 1. It said linear organopolysiloxane, one of the b units and d units contains as an essential unit, an R ³ group either end of the molecular chain and the molecular chain non-end portion only, or with both. The component (A) can be radically cured at a low temperature due to the presence of ³ R groups that are easily radically crosslinked, and the hardness of the cured product is improved by the radical crosslinking. In addition to this, the radical-curable silicone composition of the present invention has an aryl group of 10 mol% or more of the total R ² , and quantum dots are uniformly dispersed in the matrix without agglomeration, so that it can be used as a wavelength conversion material. Especially useful.

（式中、括弧内のシロキサン単位の配列は任意であり、＊は隣接ケイ素原子との結合を表す。）

（式中、括弧内のシロキサン単位の配列は任意である。）

（式中、括弧内のシロキサン単位の配列は任意である。）

Suitable examples of the component (A) are shown below, but are not limited thereto. In the formula, Me represents a methyl group and Ph represents a phenyl group (the same applies hereinafter).

(In the formula, the arrangement of the siloxane unit in parentheses is arbitrary, and * represents the bond with the adjacent silicon atom.)

(In the formula, the arrangement of siloxane units in parentheses is arbitrary.)

(In the formula, the arrangement of siloxane units in parentheses is arbitrary.)

The component (A) may be used alone or in combination of two or more.

The viscosity of the component (A) is preferably 10 to 100,000,000 mPa · s, and particularly preferably oily in the range of 200 to 10,000 mPs · s. Unless otherwise specified below, the viscosity is a value measured by a rotational viscometer at 25 ° C.

[(B) component]
The component (B) is a polymerization initiator that polymerizes the polymerizable functional group of the component (A), and the component (B) is an organic peroxide that generates radicals by heat or radicals by light such as ultraviolet rays. A photopolymerization initiator to be used can be used.

As the organic peroxide, an organic peroxide having a 10-hour half-life temperature of 50 to 150 ° C. is preferable from the viewpoint of controlling the storage stability and curability of the composition and the heat-resistant temperature of the quantum dots. More preferably, it is an organic peroxide at 60 to 110 ° C.

Specific examples of the organic peroxide include benzoyl peroxide, t-butyl perbenzoate, o-methylbenzoyl peroxide, p-methylbenzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 1,1 -Bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-di-tetrabutylperoxy-cyclohexane, 2,5-dimethyl-2,5-di (t-butylperoxy) Hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexin, 1,6-bis (p-toroil peroxycarbonyloxy) hexane, di (4-methylbenzoylperoxy) hexamethylene Examples thereof include biscarbonate, 2,5-dimethoxy-2,5-di (2-ethylhexanoylperoxy) hexane, and 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane. ..

Organic peroxides are also commercially available, for example from NOF CORPORATION. Specifically, Perbutyl NHP (50.6), Perhexyl PV (53.2), Perbutyl PV (54.6), Perloyl 355 (59.4), Perloyl L (61.6), Perocta O (65. 3), Perloyl SA (65.9), Perhexa 25O (66.2), Perhexyl O (69.9), Niper-PMB (70.6), Perbutyl O (72.1), Niper BMT (73.1) ), Niper BW (73.6), Perhexa MC (83.2), Perhexa TMH (86.7), Perhexa HC (87.1), Perhexa C (90.7), Pertetra A (94.7), Perhexyl I (95.0), Perbutyl MA (96.1), Perbutyl355 (97.1), Perbutyl L (98.3), Perbutyl I (98.7), Perbutyl E (99.0), Perhexyl Z (99.4), Perhexa 25Z (99.7), Perbutyl A (101.9), Perhexa 22 (103.1), Perbutyl Z (104.3), Perhexa V (104.5), Perbutyl P (119) .2), Park Mill D (116.4), Perhexyl D (116.4), Perhexa 25B (117.9), Perbutyl C (119.5), Perbutyl D (123.7), Permenta H (128.0) ), Perhexin 25B (128.4), Park Mill P (145.1) and the like. The numbers in parentheses following the compound name are the respective 10-hour half-life temperatures (unit: ° C.).

Of the above organic peroxides, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane is preferable from the viewpoint of compatibility with the component (A) and a 10-hour half-life temperature. (Perhexa (registered trademark) 25O manufactured by Nichiyu Co., Ltd., 10-hour half-life temperature 66.2 ° C.).

These organic peroxides can be used alone or in combination of two or more.

The amount of the organic peroxide added may be an effective amount, but is usually 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). is there.

Specific examples of the photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (Irgacure 651 manufactured by BASF), and 1-hydroxy-cyclohexyl-phenyl-ketone. (BASF Irgacure 184), 2-Hydroxy-2-methyl-1-phenyl-propan-1-one (BASF Irgacure 1173), 2-Hydroxy-1- {4- [4- (2-Hydroxy-2-) Methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (BASF Irgacure 127), phenylglycoxylic acid methyl ester (BASF Irgacure MBF), 2-methyl-1- [4-] (Methylthio) Phenyl] -2-morpholinopropan-1-one (BASF Irgacure 907), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone (BASF Irgacure 369) , Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (Irgacure 819 manufactured by BASF), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Irgacure TPO manufactured by BASF) and the like.

Of the above photopolymerization initiators, 2,2-diethoxyacetophenone and 2-hydroxy-2-methyl-1-phenyl-propane-1-one (manufactured by BASF) are preferable from the viewpoint of compatibility with the component (A). Irgacure 1173), bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (BASF's Irgacure 819), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (BASF's Irgacure TPO).

These photopolymerization initiators can be used alone or in combination of two or more.

The amount of the photopolymerization initiator added is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the component (A) from the viewpoint of curability.

[Component (C)]
The radical curable silicone composition of the present invention can further contain quantum dots as the component (C). The component (C) (quantum dot) acts as a wavelength conversion material. Quantum dots are usually particles having an average particle size of 20 nm or less, and can absorb and convert light energy. The color of light can be adjusted by changing the particle size of quantum dots. Since the band gap is determined by the size of the particle size, it is possible to obtain light with high color purity by making the particle size uniform. Further, the radical curable silicone composition containing quantum dots as the component (C) is an excellent wavelength conversion material because the quantum dots are uniformly dispersed in the matrix without agglutination.

Examples of the quantum dots that radiate in the visible light region include CdSe-based particles having shells such as CdS, ZnSe, and ZnS. Cadmium-free quantum dots such as InP, CuInS ₂ , AgInS ₂ , Te, PbS, and InAs can also be used. Any conventional quantum dot can be used in the present invention.

The component (C) can be used alone or in combination of two or more. Further, those previously dispersed in an organic solvent or the like may be used.

The amount of the component (C) added is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the component (A).

[Other ingredients]
The radical-curable silicone composition of the present invention contains a known antioxidant such as 2,6-di-t-butyl-4-methylphenol in order to suppress the occurrence of coloring, cloudiness, oxidative deterioration, etc. of the cured product. May be blended. Further, in order to impart resistance to photodegradation, a light stabilizer such as a hindered amine stabilizer may be added. Further, if necessary, an inorganic filler such as fumed silica may be blended in order to improve the strength, or a dye, a pigment, a flame retardant or the like may be blended. An adhesive aid (such as a silane coupling agent) may be added to improve the adhesive strength.

[Curing method and conditions]
Among the radical-curable silicone compositions of the present invention, known methods and conditions can be adopted as the curing method and curing conditions of the thermal radical curing type containing an organic peroxide. As an example, it can be cured in a nitrogen atmosphere at 70 to 150 ° C. for 10 minutes to 5 hours. When the polymerization initiator is an organic peroxide having a 10-hour half-life temperature of 50 to 150 ° C., low-temperature curing is possible.
Further, the photocurable type radical curable silicone composition containing a photopolymerization initiator can be cured by irradiating with light such as ultraviolet rays. Examples of the light source of ultraviolet rays include UV LED lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, carbon arc lamps, xenon lamps and the like. The irradiation amount (integrated light amount) of ultraviolet rays is preferably 1 to 10,000 mJ / cm ² and more preferably 10 to 10 mJ / cm ² with respect to a sheet obtained by molding the composition of the present invention into a thickness of about 2.0 mm. It is 9,000 mJ / cm ² . That is, when ultraviolet rays having an illuminance of 100 mW / cm ² are used, they can be cured by irradiating the ultraviolet rays for about 0.01 to 100 seconds.

Hereinafter, the present invention will be specifically described with reference to Examples, but these Examples do not limit the present invention in any way.

（式中、括弧内のシロキサン単位の配列は不定である。）

[Synthesis Example 1]
In a 2 L 4-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, 1,000 g of organopolysiloxane represented by the following formula (3) is dissolved in 500 g of toluene, and 85 using an oil bath. Heated to ° C. To this, 1 g of a toluene solution of platinum hexachloride 1,3-divinyltetramethyldisiloxane (0.5% by mass in terms of platinum) was added, and the organohydrogendisiloxane 44 represented by the following formula (4) was stirred while stirring. .3 g was added dropwise. After completion of the dropping, the mixture was stirred at 95 ° C. for 2 hours and then cooled to 25 ° C. Then, 5 g of activated carbon was added, the mixture was stirred at room temperature for 1 hour, and then removed by filtration. Toluene was distilled off under reduced pressure to obtain 842.3 g of a colorless and transparent oily reaction product (A-1) (viscosity at 25 ° C.: 6180 mPa · s).

(In the formula, the sequence of siloxane units in parentheses is indefinite.)

（式中、括弧内のシロキサン単位の配列は不定である。） [Synthesis Example 2]
In a 2 L 4-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, 1,000 g of organopolysiloxane represented by the following formula (5) is dissolved in 500 g of toluene, and 85 using an oil bath. Heated to ° C. To this, 1 g of a toluene solution of platinum hexachloride 1,3-divinyltetramethyldisiloxane (0.5% by mass in terms of platinum) was added, and the organohydrogendisiloxane 46 represented by the above formula (4) was stirred with stirring. .9 g was added dropwise. After completion of the dropping, the mixture was stirred at 95 ° C. for 2 hours and then cooled to 25 ° C. Then, 5 g of activated carbon was added, the mixture was stirred at room temperature for 1 hour, and then removed by filtration. Toluene was distilled off under reduced pressure to obtain 987.23 g of a colorless and transparent oily reaction product (A-2) (viscosity at 25 ° C.: 4,000 mPa · s).

(In the formula, the sequence of siloxane units in parentheses is indefinite.)

（式中、括弧内のシロキサン単位の配列は不定である。） [Synthesis Example 3]
200 g of organopolysiloxane represented by the following formula (6) is dissolved in 100 g of toluene in a 2 L four-necked flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, and heated to 85 ° C. using an oil bath. It was heated. To this, 0.2 g of a toluene solution of platinum hexachloride 1,3-divinyltetramethyldisiloxane (0.5% by mass in terms of platinum) was added, and the organohydrogenge represented by the above formula (4) was stirred with stirring. 30.7 g of siloxane was added dropwise. After completion of the dropping, the mixture was stirred at 95 ° C. for 2 hours and then cooled to 25 ° C. Then, 5 g of activated carbon was added, the mixture was stirred at room temperature for 1 hour, and then removed by filtration. Toluene was distilled off under reduced pressure to obtain 216.6 g of a colorless and transparent oily reaction product (A-3) (viscosity at 25 ° C.: 2,400 mPa · s).

(In the formula, the sequence of siloxane units in parentheses is indefinite.)

[Comparative Synthesis Example 1]
In a 2 L 4-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, 500 g of organopolysiloxane represented by the following formula (7) is dissolved in 250 g of toluene and heated to 85 ° C. using an oil bath. It was heated. To this, 0.1 g of a toluene solution of platinum hexachloride 1,3-divinyltetramethyldisiloxane (0.5% by mass in terms of platinum) was added, and the organohydrogenge represented by the above formula (4) was stirred with stirring. 7.8 g of siloxane was added dropwise. After completion of the dropping, the mixture was stirred at 95 ° C. for 2 hours and then cooled to 25 ° C. Then, 2.5 g of activated carbon was added, the mixture was stirred at room temperature for 1 hour, and then removed by filtration. Toluene was distilled off under reduced pressure to obtain 485 g of a colorless and transparent oily reaction product (A-4) (viscosity at 25 ° C.: 6,000 mPa · s).

（式中、括弧内のシロキサン単位の配列は不定である。） [Comparative synthesis example 2]
500 g of organopolysiloxane represented by the following formula (8) is dissolved in 250 g of toluene in a 2 L 4-neck flask equipped with a stirrer, a cooling tube, a dropping funnel and a thermometer, and the temperature is adjusted to 85 ° C. using an oil bath. It was heated. To this, 0.1 g of a toluene solution of platinum hexachloride 1,3-divinyltetramethyldisiloxane (0.5% by mass in terms of platinum) was added, and the organohydrogenge represented by the above formula (4) was stirred with stirring. 7.8 g of siloxane was added dropwise. After completion of the dropping, the mixture was stirred at 95 ° C. for 2 hours and then cooled to 25 ° C. Then, 2.5 g of activated carbon was added, the mixture was stirred at room temperature for 1 hour, and then removed by filtration. Toluene was distilled off under reduced pressure to obtain 480 g of a colorless and transparent oily reaction product (A-5) (viscosity at 25 ° C.: 5,000 mPa · s).

(In the formula, the sequence of siloxane units in parentheses is indefinite.)

[Examples 1 to 6 and Comparative Examples 1 to 6]
The components (A-1) to (A-6) shown below and the component (C) are mixed according to the compositions shown in Tables 1 and 2 (the numerical values in the table represent parts by mass), and 80 under reduced pressure conditions. Toluene was distilled off at ° C. Then, the component (B) was added and mixed uniformly to prepare a radical curable silicone composition.

（式中、括弧内のシロキサン単位の配列は不定であり、アスタリスク（＊）は隣接ケイ素原子との結合を表す。） (A) Ingredient:
(A-1) Organopolysiloxane represented by the following formula obtained in Synthesis Example 1

(In the formula, the arrangement of the siloxane unit in parentheses is indefinite, and the asterisk (*) represents the bond with the adjacent silicon atom.)

（式中、括弧内のシロキサン単位の配列は不定である。） (A-2) Organopolysiloxane represented by the following formula obtained in Synthesis Example 2

(In the formula, the sequence of siloxane units in parentheses is indefinite.)

（式中、括弧内のシロキサン単位の配列は不定である。） (A-3) Organopolysiloxane represented by the following formula obtained in Synthesis Example 3

(In the formula, the sequence of siloxane units in parentheses is indefinite.)

（Ａ−５）比較合成例２で得られた下記式で表されるオルガノポリシロキサン

（Ａ−６）上記式（３）で表されるオルガノポリシロキサン Comparative component:
(A-4) Organopolysiloxane represented by the following formula obtained in Comparative Synthesis Example 1

(A-5) Organopolysiloxane represented by the following formula obtained in Comparative Synthesis Example 2

(A-6) Organopolysiloxane represented by the above formula (3)

(B) Ingredient:
(B-1) Perhexa (registered trademark) 25O (manufactured by NOF CORPORATION, 10-hour half-life temperature 66.2 ° C)
(B-2) Irgacure 1173 (manufactured by BASF)

(C) component:
(C-1) InP / ZnS core-shell type quantum dots (manufactured by SIGMA-ALDRICH, 5 mg / mL toluene solution (quantum dot content: 0.6% by mass), emission peak: 530 nm)

The compositions obtained in Examples and Comparative Examples were evaluated by the following methods, and the results are shown in Tables 3 and 4.

[appearance]
The appearance of each composition and the cured product obtained by curing the composition under the following curing conditions were visually observed and evaluated as ◯ when the transparency was maintained and × when the composition was cloudy.

[Hardness]
-The hardness of the cured product having a thickness of 2 mm prepared by heating the thermosetting composition in a hot air circulation oven at 80 ° C. for 2 hours in a nitrogen atmosphere was measured for type A hardness at 23 ° C.
-The ultraviolet curable organopolysiloxane composition was irradiated with ultraviolet light having a wavelength of 365 nm at 25 ° C. in a nitrogen atmosphere using an eye UV electronic controller (model UBX0601-01) manufactured by Eye Graphics Co., Ltd. The type A hardness at 23 ° C. was measured for the hardness of the cured product having a thickness of 2 mm, which was cured by irradiating ultraviolet rays so as to be 000 mJ / cm ² .

As shown in Table 3, in Examples 1 to 6 using the radically curable silicone composition of the present invention, the dispersibility of the quantum dots was excellent, and the transparency was maintained even after curing. On the other hand, as shown in Table 4, in Comparative Examples 1 to 4 in which an organopolysiloxane having no phenyl group (aryl group) or a low content was used instead of the component (A) of the present invention, the quantum dots White turbidity occurred due to aggregation. In Comparative Examples 5 and 6 using the organopolysiloxane having no group (R ³ ) represented by the above formula (2), curing did not occur under the above curing conditions.

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

Claims (6)

(A) Linear organopolysiloxane represented by the following formula (1) (R ¹ R ² ₂ SiO _1/2 ) _a (R ³ R ² ₂ SiO _1/2 ) _b (R ² ₂ SiO _{2 / 2} ) _c (R ³ R ² SiO _2/2 ) _d (R ¹ R ² SiO _2/2 ) _e (1)
(In the formula, R ¹ is an alkenyl group having 2 to 8 carbon atoms, R ² is an alkyl group having 1 to 8 carbon atoms independently substituted or unsubstituted, or 6 to 8 substituted or unsubstituted carbon atoms. There are 12 aryl groups, except that at least 10 mol% of the total R ² is the aryl group, R ³ is a group represented by the following formula (2), and a, b, c, d and e are each. , A ≧ 0, b ≧ 0, c ≧ 0, d ≧ 0, e ≧ 0, and a + b> 0, b + d> 0, a + b + c + d + e = 1.

(In the formula, R ⁴ is an independently substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms, and R ⁵ is a hydrogen atom, substituted or unsubstituted alkyl group having 1 to 8 carbon atoms. , Either a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and * represents a bond with an adjacent silicon atom.),
as well as,
(B) A radical-curable silicone composition containing a polymerization initiator. The radical-curable silicone composition according to claim 1, further comprising (C) quantum dots. The radical-curable silicone composition according to claim 1 or ^2, wherein each R ² is independently a methyl group or a phenyl group. The radical-curable silicone composition according to any one of claims 1 to 3, wherein the polymerization initiator is an organic peroxide or a photopolymerization initiator. The radical curable silicone composition according to claim 4, wherein the organic peroxide has a 10-hour half-life temperature of 50 to 150 ° C. A silicone cured product, which is a cured product of the radical curable silicone composition according to any one of claims 1 to 5.