JP2013091772A - Condensation-curable polysiloxane composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condensation-curable polysiloxane composition with preferable storage stability.SOLUTION: The condensation-curable polysiloxane composition obtained by mixing an organopolysiloxane of (i) below, an organosilicon compound of (ii) below and a compound of (iii) below has preferable storage stability. (i) The organopolysiloxane has a polysiloxane main chain including at least one kind selected from a diarylsiloxane unit and an alkylarylsiloxane unit as the monomer unit, and condensing functional groups binding respectively to silicon atoms at both terminals of the main chain. (ii) The organosilicon compound has at least one aryl group binding to a silicon atom in one molecule, and at least three condensing functional groups in one molecule each binding to a silicon atom, the number of pieces among the condensing functional groups, not binding to a silicon atom where the aryl group is bound, is two or less. (iii) The compound is a gallium compound.

Description

  The present invention relates to a condensation curable polysiloxane composition.

  A condensation-curable polysiloxane composition is used as a sealing material for white LED that requires heat resistance and light resistance. The condensation-curable polysiloxane composition is typically an organopolysiloxane having two or more condensable functional groups in one molecule and an organosilicon compound having three or more condensable functional groups in one molecule. And a condensation catalyst.

  As an example of a condensation catalyst that can be used in the condensation-curable polysiloxane composition, a compound containing a metal such as zirconium, hafnium, tin, zinc, or titanium is known. Tin compounds have been pointed out to corrode electrodes, and in recent years, their use tends to be refrained in consideration of environmental effects. It has also been proposed to use a gallium compound as a condensation catalyst (see Patent Document 1).

JP 2010-1111756 A

One of the requirements for the condensation curable polysiloxane composition is an improvement in storage stability.
The main object of the present invention is to provide a condensation-curable polysiloxane composition having good storage stability.

  The present inventors have found that a condensation reaction involving a condensable functional group bonded to a silicon atom to which an aryl group is bonded is strongly influenced by temperature in the presence of a condensation catalyst containing gallium, and completed the present invention. I let you.

Embodiments of the present invention include the following condensation curable polysiloxane compositions.
(1) Condensation-curable polysiloxane composition obtained by mixing an organopolysiloxane (i) below, an organosilicon compound (ii) below, and a compound (iii) below:
(I) Organopoly having a polysiloxane main chain containing at least one selected from a diarylsiloxane unit and an alkylarylsiloxane unit as a monomer unit, and having a condensable functional group bonded to silicon atoms at both ends of the main chain. Siloxane;
(Ii) having at least one aryl group bonded to a silicon atom in one molecule and having at least three condensable functional groups bonded to a silicon atom in one molecule, and among the condensable functional groups, an aryl group An organosilicon compound in which the number of non-bonded silicon atoms is 2 or less;
(Iii) Gallium compound.
(2) The condensation-curable polysiloxane composition according to (1), wherein the organopolysiloxane of (i) includes a diphenylsiloxane unit as a monomer unit in the polysiloxane main chain.
(3) The condensation-curable polysiloxane composition according to (1), wherein the organopolysiloxane of (i) includes a methylphenylsiloxane unit as a monomer unit in the polysiloxane main chain.
(4) The condensation-curable polysiloxane composition according to (3), wherein the organopolysiloxane of (i) includes a poly (methylphenylsiloxane) unit in the polysiloxane main chain.
(5) The condensation-curable polysiloxane composition according to any one of (1) to (4), wherein the organopolysiloxane of (i) includes a dialkylsiloxane unit as a monomer unit in the polysiloxane main chain.
(6) The condensation-curable polysiloxane composition according to (5), wherein the dialkylsiloxane unit includes a dimethylsiloxane unit.
(7) The condensation-curable polysiloxane composition according to (6), wherein the organopolysiloxane of (i) includes a poly (dimethylsiloxane) unit in the polysiloxane main chain. (8) The condensation-curable polysiloxane composition according to any one of (1) to (7), wherein the organosilicon compound (ii) is an organopolysiloxane or an organosilane.
(9) The condensation according to any one of (1) to (8), wherein all the condensable functional groups of the organosilicon compound of (ii) are bonded to a silicon atom to which an aryl group is bonded. Curable polysiloxane composition.
(10) The condensation-curable polysiloxane composition according to any one of (1) to (9), wherein the aryl group of the organosilicon compound of (ii) includes a phenyl group.
(11) The condensation-curable polysiloxane composition according to (10), wherein the organosilicon compound of (ii) includes phenyltrimethoxysilane.
(12) The condensation-curable polysiloxane composition according to (10), wherein the organosilicon compound of (ii) includes a polysiloxane compound containing a phenylmethoxysiloxane unit.
(13) The hydrocarbon group bonded to the silicon atom does not contain a hydrocarbon group other than a phenyl group or a methyl group, and is expressed in molar ratio (content of methyl group bonded to the silicon atom) / (in the silicon atom The condensation-curable polysiloxane composition according to any one of (1) to (12), wherein the content of bonded phenyl groups is 1.0 to 10.
(14) The condensation-curable polysiloxane composition according to any one of (1) to (13), wherein a refractive index at 20 ° C. measured using a sodium D line is 1.48 or more.
(15) The condensation-curable polysiloxane composition according to any one of (1) to (14), wherein the gallium compound of (iii) includes at least one selected from gallium acetylacetonate and gallium acetate.
(16) The condensable functional group of the organopolysiloxane of (i) and the condensable functional group of the organosilicon compound of (ii) are each selected from a hydroxy group and an alkoxy group, The condensation-curable polysiloxane composition according to any one of 1) to (15).
(17) The condensation-curable polysiloxane composition according to any one of (1) to (16), wherein the viscosity at a liquid temperature of 25 ° C. is 500 mPa · s or more.
(18) The condensation-curable polysiloxane composition according to any one of (1) to (17), wherein the viscosity after standing at room temperature for 6 months is within 110% of the initial viscosity.

The condensation-curable polysiloxane composition described in each of (1) to (18) includes the organopolysiloxane (i), the organosilicon compound (ii), and the gallium compound (iii) It is intended to include those obtained by increasing the viscosity of the mixture by heat treatment or the like. Therefore, the condensation-curable polysiloxane compositions described in the above (1) to (18) each include a part or all of the polysiloxane (i) and the organosilicon compound (ii) of the condensation reaction product. It may be contained in a form.
In addition, the condensation-curable polysiloxane compositions described in the above (1) to (18) can be used as they are, or any additive for the purpose of controlling physical properties, imparting various functions, and modifying. Can also be used after mixing. The form of such an additive can be particulate, molecular or the like. For example, viscosity can be increased or thixotropy can be imparted by adding fumed silica to the condensation-curable polysiloxane compositions described in the above (1) to (18). In addition, the effective refractive index can be increased by adding nano-sized titanium oxide particles.

  The condensation curable polysiloxane resin according to the embodiment of the present invention is excellent in storage stability.

It is a conceptual diagram showing the one aspect | mode of the semiconductor light-emitting device using the condensation-curable polysiloxane composition of this invention.

  Hereinafter, the present invention will be described in detail according to embodiments. However, the present invention is not limited to the embodiments explicitly or implicitly described in this specification.

The condensation-curable polysiloxane composition according to the embodiment of the present invention can be obtained by mixing the following raw materials A to C.
(Raw material A) Organo having a polysiloxane main chain containing at least one selected from a diarylsiloxane unit and an alkylarylsiloxane unit as a monomer unit and having a condensable functional group bonded to silicon atoms at both ends of the main chain Polysiloxane.
(Raw material B) It has at least one aryl group bonded to a silicon atom in one molecule and has at least three condensable functional groups bonded to a silicon atom in one molecule. An organosilicon compound in which the number of groups not bonded to a bonded silicon atom is 2 or less.
(Raw material C) Gallium compound.

  An example of the raw material A is an organopolysiloxane (hereinafter referred to as “OPS-1”) represented by the following formula (1).

  In the above formula, Me represents a methyl group, and Ph represents a phenyl group. m is an integer of around 32, and n is an integer of around 7.

OPS-1 is dimethylsiloxane unit as a monomer unit (-SiMe ₂ O-) and has a polysiloxane backbone comprising diphenylsiloxane unit (-SiPh ₂ O-), silicon atoms at both ends of the main chain Each is bound with a hydroxy group which is a condensable functional group. In other words, OPS-1 has silanol groups at both ends of the siloxane main chain. There are two types of silanol groups, one is dimethylsilanol group (-SiM
e ₂ OH), and the other is a diphenylsilanol group (—SiPh ₂ OH). OPS-1 includes a species having a dimethylsilanol group at both ends, a species having a diphenylsilanol group at both ends, and a species having a dimethylsilanol group at one end and a diphenylsilanol group at the other end. .

  An example of the raw material B is an organosilicon compound (hereinafter referred to as “OSC-1”) represented by the following formula (2).

  OSC-1 is a polysiloxane (oligomer) having a low polymerization degree, and m is 4, for example. One phenyl group and two methoxy groups, which are condensable functional groups, are bonded to the silicon atoms at both ends. Therefore, OSC-1 has four condensable functional groups bonded to a silicon atom in one molecule, and all four of them are bonded to a silicon atom bonded to an aryl group.

An example of the raw material C is gallium acetylacetonate [Ga (acac) ₃ ] (also called gallium (III) 2,4-pentanedioate, tris (acetylacetonato) gallium, etc.).

The mixture of OPS-1, OSC-1, and Ga (acac) ₃ can be used as a thermosetting resin even if it has just been mixed, but usually it has increased to a predetermined viscosity. Things are put to use as finished products. Thickening is performed by subjecting the mixture to heat treatment to polycondensate raw material A and raw material B. The temperature of the heat treatment is preferably 100 to 130 ° C.
The mixture after thickening may be substantially free of OPS-1 and OSC-1 present in an unreacted state.
A mixture that has been thickened by heat treatment and returned to room temperature can be stored for a long period of time while maintaining fluidity. The composition can be cured by heating again.

The reason why this mixture exhibits such properties is considered as follows.
That is, when OPS-1, OSC-1, and Ga (acac) ₃ are mixed, condensation between dimethylsilanol groups contained in OPS-1 is gradually performed immediately after mixing due to the catalytic action of Ga (acac) _3. The reaction proceeds. Eventually, the dimethylsilanol groups contained in OPS-1 are exhausted, and most of OPS-1 and its condensate contained in the mixture have diphenylsilanol groups at both ends. The condensation reaction stops at this point.
The reason for the termination of the condensation reaction is that the condensation reaction involving the diphenylsilanol group does not proceed at room temperature even in the presence of a gallium compound due to steric hindrance due to the bulky phenyl group. For the same reason, the condensation reaction involving the methoxy group contained in OSC-1 does not proceed at room temperature. If the condensation reaction is stopped, the thickening of the mixture will not proceed.

The fact that the mixture thickens when heat-treated is due to the fact that the condensation reaction involving the diphenylsilanol group contained in OPS-1 and the methoxy group contained in OSC-1 proceeds in the presence of Ga (acac) ₃ at high temperatures. It shows that However, as described above, since this condensation reaction does not proceed at room temperature, the thickening stops when the mixture is returned to room temperature. Therefore, the mixture after thickening can be stored at room temperature for a long time.

The present inventors have confirmed that such a property cannot be obtained when a zirconium compound is used as a catalyst.
For example, a composition obtained by replacing the catalyst mixed with OPS-1 and OSC-1 from Ga (acac) ₃ to Zr (acac) ₃ does not thicken even when subjected to heat treatment, and has sufficient thermosetting properties. Not shown. Presumably, the catalytic activity of the zirconium compound is lower than that of the gallium compound, so that the condensation reaction involving the diphenylsilanol group contained in OPS-1 or the methoxy group contained in OSC-1 is sufficient even under heating. This is probably because it does not occur.

  Hereinafter, embodiments of the present invention will be described in more detail.

[1] Method for Producing Condensation Curable Polysiloxane Composition [1-1] Raw Material In the condensation curable polysiloxane composition according to the embodiment of the present invention, raw material A, raw material B and raw material C are mixed as described above. Is obtained.
[1-1-1] Raw material A
As described above, the raw material A has a polysiloxane main chain containing at least one kind selected from a diarylsiloxane unit and an alkylarylsiloxane unit as a monomer unit, and a condensable functional group bonded to silicon atoms at both ends of the main chain. It is an organopolysiloxane having a group. Here, the condensable functional group is a functional group that generates a siloxane bond by a condensation reaction with another condensable functional group.
The raw material A is not limited to the above-described OPS-1, and various materials can be used.

The aryl group in the diarylsiloxane unit or the alkylarylsiloxane unit is preferably exemplified by a phenyl group, but is not limited thereto.
The alkyl group in the alkylarylsiloxane unit is preferably exemplified by a methyl group, but is not limited thereto.

  Preferred examples of the condensable functional groups bonded to the silicon atoms at both ends of the polysiloxane main chain include, but are not limited to, hydroxy groups, alkoxy groups, acetoxy groups, enoxy groups, oxime groups, amino groups It may be a group, an amide group, a halogen group or the like. Preferable examples of the alkoxy group include an alkoxy group having 1 to 3 carbon atoms, that is, a methoxy group, an ethoxy group, and a propoxy group.

  Suitable examples of the raw material A include poly (methylphenylsiloxane) represented by the following formula (3), in which hydroxy groups are bonded to silicon atoms at both ends of the polysiloxane chain.

In the formula (3), m is an integer, preferably 6 or 7. A compound obtained by condensing the compound represented by the formula (3) to lengthen the polysiloxane chain can also be preferably used as the raw material A. In this case, a gallium compound such as Ga (acac) ₃ or gallium acetate can be preferably used as the condensation catalyst.

  Furthermore, preferred examples of the raw material A include organopolysiloxanes represented by the following formula (4).

  In the formula (4), m and n are each an integer, preferably 6 or 7. M and N are integers of 1 or more. The compound of formula (4) contains poly (methylphenylsiloxane) units and poly (dimethylsiloxane) units in the main chain. This compound can be obtained by condensing the organopolysiloxane of the formula (3) and the organopolysiloxane represented by the following formula (5).

In the formula (5), n is an integer, preferably 6 or 7. The condensation of the organopolysiloxane of the formula (3) and the organopolysiloxane of the formula (5) can be performed using a gallium compound such as Ga (acac) ₃ or gallium acetate as a catalyst.

In addition, the organopolysiloxane obtained by condensing the organopolysiloxane of the formula (1) and the organopolysiloxane of the formula (5) can also be used as the raw material A.
It is also possible to use a combination of two or more organopolysiloxanes as the raw material A. The combination and mixing ratio in that case can be appropriately set according to the purpose.

  The polystyrene equivalent weight average molecular weight of the raw material A is preferably 500 or more, and usually 700,000 or less, preferably 50000 or less, and more preferably 30000 or less. When the molecular weight of the raw material A is low, the cured product of the resulting condensation-curable polysiloxane composition tends to be hard and brittle. Moreover, when the molecular weight of the raw material A is too high, miscibility with the raw material B may worsen.

[1-1-2] Raw material B
As described above, the raw material B has at least one aryl group bonded to a silicon atom in one molecule and has at least three condensable functional groups bonded to a silicon atom in one molecule. An organosilicon compound in which the number of groups not bonded to a silicon atom to which an aryl group is bonded is 2 or less.
The raw material B is not limited to the aforementioned OSC-1, and various materials can be used.

For example, an organic silicon compound represented by the following formula (6) can be used as the raw material B.
SiX ₃ Y (6)
In the above formula (6), X represents a condensable functional group, and Y represents an aryl group.

  Specific examples of the condensable functional group X include a hydroxy group, an alkoxy group, an acetoxy group, an enoxy group, an oxime group, an amino group, an amide group, and a halogen group. As a preferable alkoxy group, a C1-C3 alkoxy group, ie, a methoxy group, an ethoxy group, and a propoxy group is mentioned.

  The aryl group Y is preferably a phenyl group, but is not limited thereto.

  Specific examples of the raw material B represented by the above formula (6) include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, p-aminophenyltrimethoxysilane, (p-chloromethyl) phenyltrimethoxysilane, 4-chlorophenyltrimethoxysilane and the like can be mentioned.

  Among these, phenyltrimethoxysilane and phenyltriacetoxysilane are particularly preferable.

  Raw material B can also be various organopolosiloxane compounds including OSC-1 described above. When the raw material B is a polysiloxane compound, the polysiloxane chain may be linear or branched. Moreover, as an organic group couple | bonded with the silicon atom contained in a polysiloxane chain, not only a methyl group and a phenyl group but a vinyl group, (gamma) -aminopropyl group, (gamma) -glycidoxypropyl group, (beta)-(3,4-). Epoxycyclohexyl) ethyl group, γ- (meth) acryloxypropyl group, γ-mercaptopropyl group, γ-chloropropyl group, β-cyanoethyl group, methylphenyl group, p-aminophenyl group, N- (2-aminoethyl) ) -3-Aminopropyl group, aminoethyl group, aminomethyl group, phenethyl group, 4-aminobutyl group, N- (6-aminohexyl) aminopropyl group, 3-chloropropyl group, (p-chloromethyl) phenyl Various organic groups such as 4-chlorophenyl group, styrylethyl group, 2-methoxyethoxy group, trifluoropropyl group, etc. Get.

It is also possible to use any combination of two types of organosilicon compounds as the raw material B.
The mixing ratio of the raw material B to the raw material A is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the raw material A.

[1-1-3] Raw material C
The raw material C is a gallium compound as described above. This gallium compound is a catalyst for polycondensing the raw material A and the raw material B.

  The gallium compound is not particularly limited as long as it is a compound containing gallium as a metal atom, and various forms such as an oxide, a salt, and a chelate complex can be used. Specific examples include gallium acetylacetonate, gallium acetate, gallium oxyacetate, triethoxygallium, tris (8-quinolinolato) gallium, gallium oxalate, gallium ethylxanthate, diethylethoxygallium, and gallium maleate. . Of these, gallium acetylacetonate and gallium acetate are particularly preferable. Two or more kinds of gallium compounds can be used in any combination.

  The amount of the gallium compound used is preferably 0.01 to 0.3 parts by weight with respect to 100 parts by weight of the raw material A.

[1-1-4] Other raw materials The condensation-curable polysiloxane composition according to the embodiment uses the raw material A and the raw material B as essential raw materials, but is further flexible by mixing the following raw material D. A cured product having excellent properties can be provided.
(Raw material D) Organopolysiloxane compounds other than Raw material A and Raw material B, which have two condensable functional groups bonded to silicon atoms in one molecule.
Examples of the raw material D include poly (dimethylsiloxane) in which a condensable functional group is bonded to each silicon atom at the end of the polysiloxane chain.

[1-1-5] Methyl group content / phenyl group content in raw material In the condensation-curable polysiloxane composition according to the embodiment of the present invention, the alkyl group content is reduced with respect to the aryl group content. Thus, the refractive index can be increased and the gas barrier property can be improved. When the hydrocarbon group bonded to the silicon atom contained in the raw material mixture is only a phenyl group and a methyl group, it is represented by a molar ratio (content of methyl group bonded to the silicon atom) / (in the silicon atom These effects can be obtained by setting the content of the bonded phenyl group to 10 or less.

  On the other hand, when this molar ratio is too small, the viscosity of the raw material mixture becomes higher than necessary due to the effect of pseudo-crosslinking due to the interaction between phenyl groups, and the cured product becomes brittle. In addition, since the gas barrier ability is increased, the condensation reaction product (water or alcohol) generated by curing in the deep part is inhibited from leaving the resin, resulting in a large difference in the curing speed between the surface and the deep part. The problem of wrinkles on the surface arises. Therefore, this molar ratio is preferably 1.0 or more.

[1-2] Thickening The condensation-curable polysiloxane composition according to the embodiment of the present invention may be a mixture of the raw material A, the raw material B, and the raw material C, but is usually thickened by a polycondensation reaction. It is considered as a finished product after going through.

  The viscosity of the condensation-curable polysiloxane composition according to the embodiment of the present invention is preferably in the range of 500 to 3000 mPa · s at a liquid temperature of 25 ° C. Viscosity can be measured using a Brookfield viscometer.

The polycondensation reaction is performed by heating the raw material mixture in a range of preferably 100 ° C. or higher and 130 ° C. or lower while blowing nitrogen gas at normal pressure or under reduced pressure.
The polycondensation reaction time is preferably in the range of 1 hour or more and 5 hours or less. The reaction time is preferably adjusted based on molecular weight control.

If the time for the polycondensation reaction is too short or the temperature is too low, more low molecular weight components remain in the composition. This low molecular weight component volatilizes at the time of curing and also causes insufficient strength of the cured product. When the reaction temperature is too high, the viscosity of the mixture rapidly increases, and it becomes difficult to control the target end point viscosity. In particular, when the reaction temperature is higher than the boiling point of the low molecular raw material, the low molecular raw material may volatilize before contributing to the reaction.
Of course, a reaction time that is too long and a reaction temperature that is too high are not preferable from the viewpoint of production cost. If the reaction is attempted for a long time at a low temperature, the catalyst may be deactivated by hydrolysis before thickening starts.
The conditions for the polycondensation reaction must be set based on the above matters.

  A solvent may be used when the inside of the system is separated during the polycondensation reaction and becomes non-uniform. As the solvent, for example, lower alcohols having 1 to 3 carbon atoms, dimethylformamide, dimethyl sulfoxide, acetone, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, methyl ethyl ketone, toluene, water and the like can be arbitrarily used. In order to prevent the polycondensation reaction from being affected, one that does not show strong acidity or basicity is selected.

  It is preferable to use the minimum amount of solvent. Moreover, it is preferable to select a solvent having a boiling point of 100 ° C. or lower, more preferably 80 ° C. or lower so that it can be easily distilled off in a later step.

  By distilling off the solvent, it is possible to prevent the occurrence of cracks due to desolvation shrinkage when the composition is cured.

  The raw material mixture thickened by the polycondensation reaction (condensation-curable polysiloxane composition according to the embodiment) is stored at room temperature or lower until use.

[1-3] Purification In order to remove foreign substances from the raw material mixture after thickening, to remove slight coloring components, and to remove halides such as trace metal impurities and chlorine compounds, it is particularly preferable to carry out purification. preferable. Purification methods include distillation (including multistage distillation), thin film distillation, water washing / separation,
Operations such as crystallization and adsorption of unnecessary components by an adsorbent are used. Among these, adsorption removal by an adsorbent is particularly preferably used. Suitable adsorbents include cation exchange resins, anion exchange resins, synthetic adsorbents, silica gel, alumina, activated carbon, activated clay, various clays, and the like. Of these, activated carbon is most suitable.

  If some or all of the gallium catalyst component is removed during the purification process using an adsorbent or the like, it is preferable to add a necessary amount of the gallium compound after the purification step.

[2] Method of curing condensation curable polysiloxane composition In order to obtain a polysiloxane cured product by curing the condensation curable polysiloxane composition according to the embodiment of the present invention, it is usually 100 ° C or higher, preferably 120 ° C or higher. More preferably, it may be maintained at a temperature of 150 ° C. or higher.

The time for maintaining the curing temperature (curing time) is determined according to the catalyst concentration, the thickness of the member to be formed with the composition, and the like. Usually, it is 0.1 hour or longer, preferably 0.5 hour or longer, more preferably 1 hour or longer.
By gradually raising the temperature to the curing temperature, foaming due to residual solvent or dissolved water vapor in the composition can be prevented, and the difference in curing speed between the deep part and the surface can be reduced. That is, it is possible to obtain a cured product having a smooth appearance, free from wrinkles, and cured uniformly to the deep part and having a good appearance. Further, when a method of curing at a low temperature and then performing a subsequent curing at a high temperature is used, internal stress is hardly generated in the obtained polysiloxane cured product, and cracks and peeling can be prevented.

[3] Application Examples The condensation-curable polysiloxane composition according to the embodiment of the present invention can be used as a sealing material for various inorganic semiconductor devices and organic semiconductor devices. Specific devices include semiconductor light emitting devices such as light emitting diodes (LEDs) and semiconductor lasers, photodetectors, electro-optical displays, organic light emitting diodes (OLEDs), electroluminescent displays, organic solar cell (OPV) devices, and lighting devices. Etc. Furthermore, it can also be used for an optical element material such as a lens, a light guide plate, and a light diffusion plate, or an adhesive for the optical element.

  As an example, FIG. 1 shows a cross-sectional view of a semiconductor light emitting device using a condensation curable polysiloxane composition according to an embodiment of the present invention. The semiconductor light emitting device shown in FIG. 1 includes a semiconductor light emitting element 1, a resin molded body 2, a bonding wire 3, a sealing material 4, and a lead frame 5.

  The semiconductor light emitting element 1 is any one of a near ultraviolet LED, a purple LED, and a blue LED.

The resin molded body 2 is molded together with the lead frame 5.
The lead frame 5 is made of a conductive metal and plays a role of supplying a current to the semiconductor light emitting element 1.

  The bonding wire 3 has a role of electrically connecting the semiconductor light emitting element 1 and the lead frame 5.

The semiconductor light emitting element 1 is installed in a recess provided in the resin molded body 2 and sealed with a sealing material 4.
For the sealing material 4, the condensation-curable polysiloxane composition according to the embodiment of the present invention is used. That is, the sealing material 4 is a cured product of this condensation-curable polysiloxane composition.

A particulate phosphor is disposed inside the sealing material 4. For example, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu
Blue phosphor such as Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Sr, Ba) ₂ SiO ₄ : Eu, β-type sialon: Green phosphor such as Eu, Y ₃ Al ₅ O ₁₂ : Ce, (Y, Gd) ₃ Al ₅ O ₁₂ : Yellow phosphor such as Ce, (Sr, Ca, Ba, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) ₂ Si ₅ (N, O ) ₈ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (La, Y) ₂ O ₂ S: Eu, K ₂ SiF ₆ : Mn is a red phosphor such as Mn.

The refractive index of the sealing material 4 that is a cured product of the condensation-curable polysiloxane composition according to the embodiment of the present invention is substantially the same as the refractive index of the composition. Increasing the refractive index of the sealing material 4 is useful for preventing light from being trapped inside the phosphor particles surrounded by the sealing material 4. This is because the refractive index of the inorganic phosphor is usually higher than that of polysiloxane.
For this reason, the refractive index of the sealing material 4 at 20 ° C. measured using sodium D line (wavelength 589 nm) is preferably 1.48 or more, more preferably 1.50 or more.

  An Abbe refractometer (using sodium D line (589 nm)) can be used to measure the refractive index.

  The sealing material 4 may further contain inorganic oxide fine particles such as silica, barium titanate, titanium oxide, zirconium oxide, niobium oxide, aluminum oxide, cerium oxide, yttrium oxide, and diamond fine particles.

  These inorganic fine particles are added to the sealing material 4 for the purpose of a light scattering material, an aggregate, a thickener (thixotropic agent), a refractive index adjusting agent, and the like.

Generally, the hardness of the sealing material 4 is preferably 10 or more and 80 or less in Shore A (or JIS Type A). More preferably, it is 20 or more and 80 or less, More preferably, it is 30 or more and 70 or less. If the hardness is below this range, the purpose of protecting the semiconductor light emitting device 1 cannot be achieved. On the other hand, if the hardness exceeds this range, the function of relaxing the thermal stress is reduced, so that the bonding wire 3 is cut and the resin molded body 2 and the sealing material 4 are likely to be peeled off.

  In addition, the condensation-curable polysiloxane composition according to the embodiment of the present invention can also be used as a die bond agent for bonding the semiconductor light emitting element 1 to the resin molded body 2 or the lead frame 5.

[Experimental result]
The results of trial production and evaluation of the condensation-curable polysiloxane composition conducted by the present inventors will be described below.
1. Raw materials Table 1 shows the raw materials of the condensation curable polysiloxane composition used in the following experimental examples and comparative experimental examples. When referring to each raw material in the following description, the abbreviations shown in Table 1 are used.

YF3804 contains an organopolysiloxane having a structure represented by the formula (1) as a main component.
XC96-723 contains an organopolysiloxane having a structure represented by the above formula (5) (n is 6 to 7 on average) as a main component.
The FLD 516 contains an organopolysiloxane having a structure represented by the formula (3) (m and n are 6 to 7 on average) as a main component.
DC3037 contains an organopolysiloxane having a structure represented by the formula (2) (m is 4) as a main component.
KR213 is an organopolysiloxane containing a siloxy unit represented by the following formula (7), a siloxy unit represented by the following formula (8), and a siloxy unit represented by the following formula (9) in a molar ratio of 6/13/13. A siloxane composition (a mixture of organopolysiloxane oligomers).

2. Measurement / Evaluation Method 2.1 Methyl / Phenyl Molar Ratio In the condensation curable polysiloxane composition, expressed as a molar ratio (content of methyl group bonded to silicon atom) / (content of phenyl group bonded to silicon atom) ¹ H-NM in deuterated chloroform of each material at room temperature using NMR AL-400 manufactured by JEOL Ltd.
R was measured and calculated from the integration ratio.

2.2 Shore A hardness An 8 mm-thick measurement sample was prepared by stacking eight cured products of a condensation-curable polysiloxane composition formed into a disk shape having a thickness of 1 mm, and a rubber hardness meter KR manufactured by Furusato Seiki Seisakusho Co., Ltd. Measurement was carried out with a load of 1 kgf using -24A.
2.3 Refractive Index The refractive index at the wavelength of sodium D-line was measured at 20 ° C. using a Refractometer RX-7000α manufactured by Atago Co., Ltd. for the condensation curable polysiloxane composition and the cured product thereof.
2.4 Viscosity The viscosity of the condensation-curable polysiloxane composition was measured using a Brookfield RV viscometer RVDV-2 + Pro.

3. Synthesis and Evaluation 3.1 Experimental Example 1
300 g of YF3804 as raw material A, 16.5 g of DC3037 as raw material B, and 0.3 g of Ga (acac) ₃ as raw material C were weighed, and these were placed in a three-necked Kolben equipped with a stirring blade and a condenser. Mixing was stirred at room temperature for 15 minutes until the catalyst was fully dissolved. Thereafter, the mixture was heated to 100 ° C., and the pressure was reduced to 1.3 kPa for 1 hour, then further heated to 130 ° C. and the pressure was reduced to 1.3 kPa for 3 hours and 45 minutes. The polycondensation reaction was carried out by heating and stirring while distilling off the low-boiling silicon component and by-products, thereby obtaining a solvent-free condensation-curable polysiloxane composition. This composition had a refractive index of 1.48, a methyl / phenyl molar ratio of 4.68, and a viscosity of 502 mPa · s.

  An independent circular transparent elastomer having a thickness of about 1 mm is obtained by placing 2 g of the condensation-curable polysiloxane composition obtained in the above procedure in a Teflon (registered trademark) petri dish having a diameter of 5 cm and holding it at 150 ° C. for 3 hours under a slight breeze. A film (cured product) was obtained. This film had a Shore A hardness of 34. The refractive index of this film was 1.48, which was the same as the value of the composition before curing.

3.2 Experimental example 2
A condensation-curable polysiloxane composition was obtained in the same manner as in Experimental Example 1 except for the following points.
-FLD516 was used instead of YF3804.
-KR213 was used instead of DC3037.
The conditions for the polycondensation reaction at 100 ° C. for 1 hour were changed from 1.3 kPa under reduced pressure to normal pressure in a nitrogen gas atmosphere.
The polycondensation reaction time at 130 ° C. and 1.3 KPa reduced pressure was reduced from 3 hours 45 minutes to 40 minutes.
The resulting condensation-curable polysiloxane composition had a refractive index of 1.55, a methyl / phenyl molar ratio of 0.97, and a viscosity of 930 mPa · s.

  Preparation and evaluation of a cured product of this condensation-curable polysiloxane composition were performed in the same manner as in Experimental Example 1. As a result, the Shore A hardness was 47, and the refractive index was 1.55.

3.3 Experimental example 3
A condensation-curable polysiloxane composition was obtained in the same manner as in Experimental Example 2 except for the following points.
-PTMS was used instead of KR213.
-The polycondensation reaction time under reduced pressure of 130 ° C and 1.3 KPa was extended to 50 minutes.
The resulting condensation-curable polysiloxane composition had a refractive index of 1.55, a methyl / phenyl molar ratio of 0.97, and a viscosity of 1043 mPa · s.

Preparation and evaluation of a cured product of this condensation-curable polysiloxane composition were performed in the same manner as in Experimental Example 1. As a result, the Shore A hardness was 46 and the refractive index was 1.55.
Table 2 shows the results of examining the change in viscosity when the condensation-curable polysiloxane composition obtained in Experimental Example 3 was stored at room temperature. In addition, it represents with a relative value when an initial value is set to 100%.

3.4 Experimental Example 4
A condensation-curable polysiloxane composition was obtained in the same manner as in Experimental Example 3 except for the following points.
The conditions for the polycondensation reaction under reduced pressure of 1.3 KPa were changed from 130 ° C. and 50 minutes to 120 ° C. and 65 minutes.
The resulting condensation-curable polysiloxane composition had a refractive index of 1.55, a methyl / phenyl molar ratio of 0.97, and a viscosity of 1050 mPa · s.

  Preparation and evaluation of a cured product of this condensation-curable polysiloxane composition were performed in the same manner as in Experimental Example 1. As a result, the Shore A hardness was 38 and the refractive index was 1.55.

3.5 Comparative Experiment Example 1
A condensation-curable polysiloxane composition was obtained in the same manner as in Experimental Example 4 except for the following points.
-YF3804 was used instead of FLD516.
· Ga _{(acac) 3} instead of using _{Sn (C 8 H 15 O 2} ) 2.
-The conditions for the polycondensation reaction under normal pressure in a nitrogen gas atmosphere were changed from 100 ° C for 1 hour to 25 ° C for 30 minutes.
-The polycondensation reaction conditions of 130 ° C. and 1.3 KPa under reduced pressure for 50 minutes were changed to 25 ° C. and 1.0 KPa under reduced pressure for 30 minutes.
The resulting condensation-curable polysiloxane composition had a refractive index of 1.48 and a methyl / phenyl molar ratio of 4.38.
Production of a cured product of this condensation-curable polysiloxane composition and measurement of hardness were carried out in the same manner as in Experimental Example 1. As a result, the Shore A hardness was 25.

3.6 Comparative Experiment Example 2
A condensation-curable polysiloxane composition was obtained in the same manner as in Comparative Experimental Example 1 except for the following points. -DC3037 was used instead of PTMS.
-The conditions for the polycondensation reaction were 15 minutes under the pressure.
The conditions for the polycondensation reaction at 25 ° C. were changed from 30 minutes under reduced pressure of 1.0 KPa to 15 minutes under normal pressure.
The resulting condensation-curable polysiloxane composition had a refractive index of 1.48 and a methyl / phenyl molar ratio of 5.08.

  Production of a cured product of this condensation-curable polysiloxane composition and measurement of hardness were carried out in the same manner as in Experimental Example 1. As a result, Shore A hardness was 24.

3.7 Comparative Experiment Example 3
300 g of a 1: 1 (weight ratio) mixture of YF3804 and XC96-723 as raw material A, 30 g of PTMS as raw material B, and 0.64 g of Zr (acac) ₄ as raw material C were weighed and mixed under normal pressure. The reaction was carried out in a nitrogen gas atmosphere at 120 ° C. for 2 hours, and then nitrogen gas was blown in with SV20, and the resulting methanol, water and by-product low-boiling silicon components were distilled off, and the mixture was further stirred for 6 hours at 120 ° C. The reaction proceeded. Here, “SV” is an abbreviation for “Space Velocity” and means the volume of blown volume per unit time. SV20 means blowing nitrogen gas in a volume 20 times that of the reaction liquid in one hour.

  After stopping the blowing of nitrogen gas and once cooling the reaction solution to room temperature, the reaction solution is transferred to an eggplant type flask, and heated on an oil bath at 120 ° C. under a reduced pressure of 1 kPa for 20 minutes using a rotary evaporator. The remaining methanol and moisture and low boiling silicon component were distilled off to obtain a condensation curable polysiloxane composition. This curable composition had a refractive index of 1.47 and a methyl / phenyl molar ratio of 9.12.

  Preparation of a cured product of this condensation-curable polysiloxane composition and measurement of hardness were attempted in the same manner as in Experimental Example 1. However, the cured product was brittle, and the hardness tester needle stuck in the sample at a numerical value of about 20, and it was impossible to measure the hardness accurately. From this result, it is considered that the cured product of Comparative Experimental Example 3 had a large amount of unreacted material and insufficient crosslinking.

3.8 Comparative Experiment Example 4
a. Synthesis of raw material A 210 g of FLD516, 90 g of XC96-723, and 0.10 g of Ga (OAc) ₃ were weighed, and these were measured at 120 ° C. in a three-necked Kolben equipped with a stirring blade and a condenser. Stir for minutes to mix. Thereafter, under reduced pressure of 1.3 kPa, while distilling off the generated moisture and by-product low boiling silicon components, the mixture was heated and stirred at 120 ° C. for 1 hour to proceed the polycondensation reaction. A composition was obtained. Ga (OAc) ₃ used for the catalyst remains in the obtained composition.

The refractive index of this polysiloxane composition was 1.50.
This polysiloxane composition contains an organopolysiloxane having a structure represented by the formula (4).

b. Synthesis and Evaluation of Condensation Curable Polysiloxane Composition As a raw material A, a. A condensation curable polysiloxane composition was synthesized using MTMS as the raw material B and Ga (OAc) ₃ remaining in the raw material A as the raw material C.

Specifically, the a. The polysiloxane composition (containing Ga (OAc) ₃ ) and MTMS obtained in 1 above are produced in a three-necked Kolben equipped with a stirring blade and a condenser at low pressure of methanol, water and by-products produced under normal pressure. While distilling off the silicon component, the polycondensation reaction was carried out by heating and stirring at 100 ° C. for 30 minutes to obtain a solvent-free condensation-curable polysiloxane composition.

The refractive index of this curable polysiloxane composition was 1.50.
Subsequently, production and evaluation of a cured product of this condensation-curable polysiloxane composition were performed in the same manner as in Experimental Example 1. As a result, the Shore A hardness was 50 and the refractive index was 1.50.

3.9 Comparative Experiment Example 5
A condensation-curable polysiloxane composition was obtained in the same manner as Comparative Experimental Example 4 except for the following points. -Ga (acac) ₃ was used instead of Ga (OAc) ₃ .

The resulting condensation curable polysiloxane composition had a refractive index of 1.50.
Subsequently, production and evaluation of a cured product of this condensation-curable polysiloxane composition were performed in the same manner as in Experimental Example 1. As a result, the Shore A hardness was 37 and the refractive index was 1.50.

3.10 Comparative Experiment Example 6
a. Synthesis of Raw Material A A polysiloxane composition for raw material A was obtained in the same manner as in Comparative Experimental Example 4 except for the following points. In the synthesis of raw material A, YF3804 was used instead of XC96-723 (mixed with 240 g of FLD516 and 60 g of YF3804).
-In the synthesis | combination of the raw material A, the time of the polycondensation reaction under 120 degreeC and 1.3 KPa pressure reduction was shortened from 1 hour to 30 minutes.

  The refractive index of the polysiloxane composition obtained as the raw material A was 1.53.

b. Synthesis and Evaluation of Condensation Curable Polysiloxane Composition A condensation curable polysiloxane composition was prepared in the same manner as in Comparative Example 5 except that the raw material A was changed and the mixing ratio of the raw material A and the raw material B was changed. Tried to get.

However, although the composition had fluidity at the stage immediately after the polycondensation reaction step (viscosity 3000 mPa · s), the contents of the reaction vessel were allowed to stand for about half a day until the temperature in the reaction vessel dropped to room temperature. The whole was completely gelled.
Thus, in Comparative Experimental Example 6, a curable polysiloxane composition that could be stored at room temperature could not be obtained. The condensation-curable polysiloxane compositions of Comparative Experimental Examples 4 and 5 also had a rapid increase in viscosity during storage, and the storage stability was not good.

3.11 Experimental example 5
A blue LED chip having an emission wavelength of 450 nm is mounted on an LED package (NCI7070 (silver electrode)) having a ceramic reflector manufactured by Nippon Carbide Industries, Ltd., and the condensation-curable polysiloxane composition obtained in Experimental Example 4 is used. And sealed. The polysiloxane composition was cured by holding at 110 ° C. for 3 hours and then at 150 ° C. for 3 hours under a slight breeze. The LED samples thus obtained were subjected to the following durability test.

  The LED sample was lit by continuously flowing a current of 350 mA in each atmosphere of 25 ° C./55% RH, 85 ° C./90% RH, and 60 ° C./90% RH. The output retention rate (compared with the initial lighting) at the time when 631 hours had elapsed was measured using a 4-inch integrating sphere spectroscopic system (spectrometer: USB4000) manufactured by Ocean Optics, Inc., under a 25 ° C./55% RH atmosphere. The values were 98% for lighting up, 97% for lighting under 85 ° C./90% RH atmosphere, and 96% for lighting under 60 ° C./90% RH atmosphere.

3.12 Summary Tables 3 to 5 show a summary of sample preparation conditions and evaluation results in Experimental Examples 1 to 4 and Comparative Experimental Examples 1 to 6 described above.

  The application of the condensation curable polysiloxane composition of the present invention is not particularly limited and may be used for any application, but can be suitably used for an application of a sealing material for a semiconductor device.

DESCRIPTION OF SYMBOLS 1 Semiconductor light emitting element 2 Resin molding 3 Bonding wire 4 Sealing material 5 Lead frame

Claims (18)

Condensation-curable polysiloxane composition obtained by mixing organopolysiloxane (i) below, organosilicon compound (ii) below, and compound (iii) below:
(I) Organopoly having a polysiloxane main chain containing at least one selected from a diarylsiloxane unit and an alkylarylsiloxane unit as a monomer unit, and having a condensable functional group bonded to silicon atoms at both ends of the main chain. Siloxane;
(Ii) having at least one aryl group bonded to a silicon atom in one molecule and having at least three condensable functional groups bonded to a silicon atom in one molecule, and among the condensable functional groups, an aryl group An organosilicon compound in which the number of non-bonded silicon atoms is 2 or less;
(Iii) Gallium compound. The condensation-curable polysiloxane composition according to claim 1, wherein the organopolysiloxane (i) includes a diphenylsiloxane unit as a monomer unit in the polysiloxane main chain. The condensation-curable polysiloxane composition according to claim 1, wherein the organopolysiloxane (i) includes a methylphenylsiloxane unit as a monomer unit in the polysiloxane main chain. The condensation-curable polysiloxane composition according to claim 3, wherein the organopolysiloxane (i) includes a poly (methylphenylsiloxane) unit in the polysiloxane main chain. The condensation-curable polysiloxane composition according to any one of claims 1 to 4, wherein the organopolysiloxane (i) includes a dialkylsiloxane unit as a monomer unit in the polysiloxane main chain.   The condensation-curable polysiloxane composition according to claim 5, wherein the dialkylsiloxane unit comprises a dimethylsiloxane unit. The condensation-curable polysiloxane composition according to claim 6, wherein the organopolysiloxane (i) includes a poly (dimethylsiloxane) unit in the polysiloxane main chain.   The condensation-curable polysiloxane composition according to any one of claims 1 to 7, wherein the organosilicon compound (ii) is an organopolysiloxane or an organosilane.   The condensation-curable polysiloxane according to any one of claims 1 to 8, wherein all the condensable functional groups of the organosilicon compound (ii) are bonded to a silicon atom to which an aryl group is bonded. Composition.   The condensation curable polysiloxane composition according to any one of claims 1 to 9, wherein the aryl group of the organosilicon compound (ii) includes a phenyl group.   The condensation-curable polysiloxane composition according to claim 10, wherein the organosilicon compound (ii) comprises phenyltrimethoxysilane.   The condensation-curable polysiloxane composition according to claim 10, wherein the organosilicon compound (ii) includes a polysiloxane compound containing a phenylmethoxysiloxane unit.   Does not contain any phenyl group or hydrocarbon group other than methyl group as the hydrocarbon group bonded to the silicon atom, and expressed in molar ratio (content of methyl group bonded to silicon atom) / (phenyl bonded to silicon atom) The condensation-curable polysiloxane composition according to any one of claims 1 to 12, wherein the group content is 1.0 to 10.   The condensation-curable polysiloxane composition according to any one of claims 1 to 13, wherein a refractive index at 20 ° C measured using sodium D-line is 1.48 or more. The condensation curable polysiloxane composition according to any one of claims 1 to 14, wherein the gallium compound (iii) includes at least one selected from gallium acetylacetonate and gallium acetate. 16. The condensable functional group of the organopolysiloxane (i) and the condensable functional group of the organosilicon compound (ii) are each selected from a hydroxy group and an alkoxy group. The condensation-curable polysiloxane composition according to any one of the above.   The condensation-curable polysiloxane composition according to any one of claims 1 to 16, wherein the viscosity at a liquid temperature of 25 ° C is 500 mPa · s or more. The condensation-curable polysiloxane composition according to any one of claims 1 to 17, wherein the viscosity after standing for 6 months at room temperature is within 110% of the initial viscosity.