JP2013221082A - Addition-curing type silicone resin composition, and sheet comprising the composition, sheet-like cured product, and die attach material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an addition-curable type silicone resin composition in which a conductive filler is uniformly dispersed in a dispersion state stable with the passage of time and which can easily be handled, and to provide a silicone resin composition sheet which comprises the composition and can readily be formed into, for example, ITO of a solar battery surface, silicon wafer or the like with a conventional assembly device.SOLUTION: An addition-curing type silicone resin composition includes (A) an organopolysiloxane of a resin structure containing a structure which comprises RSiOunits, RSiOunits, and RRSiOunits, wherein at least a part of the RSiOunits are continuously repeated, and the repeating number is 10-50, (B) an organo hydrogen polysiloxane of a resin structure containing a structure which comprises RSiOunits, RSiOunits, and RHSiOunits, wherein at least a part of the RSiOunits are continuously repeated, and the repeating number is 10-50, (C) a platinum group metal-based catalyst, and (D) a conductive filler, characterized in that the composition has a solid-like state or a semi-solid-like state at room temperature.

Description

  The present invention relates to an addition-curable silicone resin composition, in particular, a conductive filler-containing silicone resin composition, and a sheet, a sheet-like cured product, and a die attach material comprising the composition.

  Pastes containing conductive fillers made of various metal powders such as silver particles are widely used as electrode materials and semiconductor chip adhesives that require electrical conductivity (Patent Documents 1 and 2). Silicone resin is attracting attention as a binder resin for silver particles because of its excellent flexibility and reflow resistance (Patent Document 3).

  In general, when using a conductive filler-containing paste, for example, it is applied to a substrate by a printing method, or dropped onto a substrate by a potting method and then brought into close contact with a target by pressing a chip, and then heated. The method of hardening is taken. However, since the paste that has flowed out other than necessary portions causes contamination and cracks, a film-like electrode material and an adhesive have been desired.

  In addition, since the conductive filler generally has a higher specific gravity than the resin, it is likely to settle in a liquid resin paste and it is difficult to obtain a stable dispersion state. For this reason, in order to obtain a resin having a uniform conductive filler distribution, it is necessary to solidify immediately after the dispersion, which limits the working time and the like.

JP 2011-066134 A JP 2010-238979 A Japanese Patent Application Laid-Open No. 10-289962

  The present invention has been made in view of the above problems, and the addition-curable silicone resin composition in which the conductive filler is uniformly dispersed, the dispersion state is stable over time, and is easy to handle, and the An object of the present invention is to provide a silicone resin composition sheet comprising a composition, which can be easily formed on, for example, ITO (Indium-Tin-Oxide) or a silicon wafer on the surface of a solar cell using a conventional assembly device. And

In order to solve the above problems, the present invention provides:
(A) R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , And R ³ independently represents any of a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, and a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, and a is 0, 1 or 2 , B is 1 or 2, and a + b is 2 or 3.)
An organopolysiloxane having a resin structure including a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50;
(B) R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² and R ³ is independently as described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.
Resin-structured organohydrogenpolysiloxane comprising a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50: in the component (A) The amount of hydrogen atoms bonded to silicon atoms in component (B) relative to the total of vinyl groups and allyl groups is 0.1 to 4.0 by molar ratio,
Provided is an addition-curable silicone resin composition comprising (C) a platinum group metal-based catalyst: an effective amount for curing, and (D) a conductive filler, which is solid or semisolid at room temperature. .

  Such an addition-curable silicone resin composition of the present invention is handled because the conductive filler is uniformly dispersed, the dispersion state is stable over time, and is solid or semi-solid at room temperature. It is easy.

It is preferable that 100 to 1500 parts by mass of the conductive filler of the component (D) is contained with respect to 100 parts by mass of the total of the components (A) to (C).
If it is such content, the composition of this invention can be widely utilized as an adhesive agent etc. of an electrode material or a semiconductor chip.

Moreover, it is preferable that the electrical resistivity in 20 degreeC of the conductive filler of the said (D) component is 0.1 ohm * m or less.
If the conductive filler has such an electrical resistivity, the volume resistance of the composition can be kept low, and the electrical conductivity becomes better.

Moreover, it is preferable that the conductive filler of the component (D) is silver.
Silver is preferred because of its low electrical resistivity and particularly excellent electrical conductivity.

Moreover, this invention provides the silicone resin composition sheet formed by shape | molding the said composition in a sheet form.
Since such an addition curable silicone resin composition sheet of the present invention is solid or semi-solid at room temperature in an uncured state (under non-heat treatment), it is easy to handle and has good workability.

The present invention also provides a die attach material comprising the composition.
Such a die attach material is easy to handle, and in addition, since the conductive filler is uniformly dispersed, the die attach material is composed of the composition of the present invention having good electrical conductivity. Become a material.

Moreover, this invention provides the sheet-like hardened | cured material formed by hardening | curing the said silicone resin composition sheet.
Such a sheet-like cured product has advantages that it is a hard resin, has excellent flexibility, has little surface tack, and can be easily molded by a conventional molding apparatus.

Furthermore, this invention provides the die attach material which consists of the said sheet-like hardened | cured material.
Since such a die attach material is made of the sheet-like cured product of the present invention having the advantage that the conductive filler is uniformly dispersed therein and the stability of the dispersibility is high, the die attach material has a high quality. Become a material.

  As described above, the addition-curable silicone resin composition of the present invention and the composition sheet comprising the same are easy to handle and have good workability because they are solid or semi-solid at room temperature in an uncured state. Therefore, the composition sheet can be easily disposed and bonded to a solar battery cell or a silicon wafer. Moreover, since it is solid or semi-solid in an uncured state, the filled conductive filler does not separate or settle during storage of the composition or composition sheet. In addition, the silicone resin composition sheet can be easily disposed and adhered to a solar battery cell or a silicon wafer even with a mounting device such as an ordinary die bond mounter. Then, by curing the thus bonded composition sheet, a cured resin layer in which the conductive filler is uniformly dispersed can be efficiently and stably formed with a uniform layer thickness. Therefore, if the composition sheet of the present invention is used, a solar cell module and a semiconductor element can be manufactured with excellent mass productivity. Moreover, since the conductive filler is uniformly dispersed in the conductive filler-containing silicone resin layer of the obtained solar cell module or the like, the electrical conductivity is good. Furthermore, this silicone resin layer is excellent in flexibility while being a hard resin, and has little surface tack.

Hereinafter, the present invention will be described in more detail.
As mentioned above, since the paste containing the conventional conductive filler is easy to settle, it is necessary to solidify quickly after being dispersed, so there is a limitation in working time, etc. There was a problem in handling, such as the paste flowing out to cause contamination and cracks.

  As a result of intensive studies to solve the above problems, the present inventors have found that the composition containing an organopolysiloxane having a characteristic structure of D units and an organohydrogenpolysiloxane has the above problems. The present invention has been completed.

That is, the addition-curable silicone resin composition of the present invention is
(A) R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , And R ³ independently represents any of a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, and a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, and a is 0, 1 or 2 , B is 1 or 2, and a + b is 2 or 3.)
An organopolysiloxane having a resin structure including a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50;
(B) R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² and R ³ is independently as described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.
Resin-structured organohydrogenpolysiloxane comprising a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50: in the component (A) The amount of hydrogen atoms bonded to silicon atoms in component (B) relative to the total of vinyl groups and allyl groups is 0.1 to 4.0 by molar ratio,
(C) Platinum group metal catalyst: It contains a curing effective amount and (D) a conductive filler, and is solid or semi-solid at room temperature.

Hereinafter, the present invention will be described more specifically, but the present invention is not limited thereto.
In the present specification, “normal temperature” means an ambient temperature in a normal state, usually a temperature in the range of 15 to 30 ° C., and typically 25 ° C.

The “solid” composition of the present invention has plasticity.
“Semi-solid” means a state of a substance that has plasticity and can retain the shape for at least 1 hour, preferably 8 hours or more when formed into a specific shape. Thus, for example, a flowable material having a very high viscosity at room temperature is essentially flowable, but changes to the applied shape in a short time of at least 1 hour (ie, breakage) due to the very high viscosity. ) Cannot be seen with the naked eye, the substance is in a semi-solid state.
In such a solid or semi-solid state, the composition has good handleability and high workability.

[Addition-curing silicone resin composition]

-(A) Resin-structured organopolysiloxane-
The organopolysiloxane having a resin structure (that is, a three-dimensional network structure), which is an important component (A) of the composition of the present invention, includes R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ^3. _a R ⁴ _b SiO _{(4-ab) / 2} units (wherein R ¹ , R ² , and R ³ represent a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group) , R ⁴ independently represents a vinyl group or an allyl group, a is 0, 1 or 2, b is 1 or 2, and a + b is 2 or 3.
A structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions is 10 to 50, preferably 15 to 45, more preferably 20 to 35, is partially Is an organopolysiloxane having a resin structure.

When the number of R ² ₂ SiO _2/2 units is 9 or less, the composition does not have plasticity, the handling property is poor, or the sheet-like cured product when the composition is cured is Since it will be in a very weak state and it will become difficult to maintain a sheet shape, it is not preferable. Moreover, when the R ² ₂ SiO _2/2 unit exceeds 50, the composition cannot maintain a solid or semi-solid state, or the sheet-like cured product becomes very soft. Handling and workability deteriorate, which is not preferable.

（ここで、ｍは１０〜５０の整数）
で表される直鎖状ジオルガノポリシロキサン連鎖構造を意味する。 The structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50 is the following general formula (1):

(Where m is an integer from 10 to 50)
The linear diorganopolysiloxane chain structure represented by these is meant.

(A) At least a part of the entire R ² ₂ SiO _2/2 unit present in the organopolysiloxane of the component, preferably 50 mol% or more (50 to 100 mol%), particularly 80 mol% or more (80 to 100 Mol%) preferably forms a chain structure represented by the general formula (1) in the molecule.

In the molecule of component (A), the R ² ₂ SiO _2/2 unit works to stretch the polymer molecule in a straight line, and the R ¹ SiO _3/2 unit branches the polymer molecule or forms a three-dimensional network. Let R ³ _a R ⁴ _b SiO _{(4-ab) / 2} R ⁴ (independently a vinyl group or an allyl group) in the unit is R ³ _c H _d SiO _(4- It serves to cure the composition of the present invention by hydrosilylation addition reaction with hydrogen atoms (ie, SiH groups) bonded to _{cd) / 2} units of silicon atoms.

(A) The molar ratio of the three essential siloxane units constituting the component, that is, R ¹ SiO _3/2 units: R ² ₂ SiO _2/2 units: R ³ _a R ⁴ _b SiO _{(4-ab) / 2} unit has a molar ratio of 90 to 24:75 to 9:50 to 1, particularly 70 to 28:70 to 20:10 to 2 (provided that the total is 100). preferable.

  Moreover, when the polystyrene conversion weight average molecular weight of this (A) component by gel permeation chromatography (GPC) exists in the range of 3,000-1,000,000, especially 10,000-100,000, workability | operativity is. From the viewpoint of curability and the like.

  Such an organopolysiloxane having a resin structure is obtained by combining compounds as raw materials for each unit so that the above three kinds of siloxane units have a required molar ratio in the produced polymer, for example, in the presence of a catalyst such as an acid. It can be synthesized by carrying out cohydrolytic condensation.

Here, as raw materials for the R ¹ SiO _3/2 unit, MeSiCl ₃ , EtSiCl ₃ , PhSiCl ₃ (hereinafter Me represents a methyl group, Et represents an ethyl group, Ph represents a phenyl group), n-propyltrichlorosilane, Examples include chlorosilanes such as cyclohexyltrichlorosilane, alkoxysilanes such as methoxysilane corresponding to these chlorosilanes, and the like.

（ここで、ｍ１＝８〜４８の整数（平均値）、ｍ２＝５〜４８の整数（平均値）、ｍ３＝０〜４３の整数（平均値）、ただし、ｍ２＋ｍ３は８〜４８の整数）
等を例示することができる。 As a raw material of R ² ₂ SiO _2/2 unit,

(Where m1 = integer of 8-48 (average value), m2 = integer of 5-48 (average value), m3 = 0-43 (average value), where m2 + m3 is an integer of 8-48
Etc. can be illustrated.

Further, R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units are R ³ R ⁴ SiO _2/2 units, R ³ ₂ R ⁴ SiO _1/2 units, and R ⁴ ₂ SiO _2/2 units. , And R ³ R ⁴ ₂ SiO _1/2 means one siloxane unit or a combination of two or more siloxane units. The raw materials include chlorosilanes such as Me ₂ ViSiCl, MeViSiCl ₂ , Ph ₂ ViSiCl, PhViSiCl ₂ (hereinafter Vi represents a vinyl group), alkoxysilanes such as methoxysilane corresponding to each of these chlorosilanes, and the like Can be illustrated.

In the present invention, when the organopolysiloxane of component (A) is produced by co-hydrolysis and condensation of the above raw material compounds, the resulting organopolysiloxane of component (A) is added to R ¹ SiO _3/2. The unit, R ² ₂ SiO _2/2 unit and / or R ³ _a R ⁴ _b SiO _{(4-ab) / 2} unit may contain a siloxane unit having a silanol group. The organopolysiloxane of component (A) is usually 10 mol% or less (0.1 to 10 mol%), preferably 5 mol% or less (0.1 mol%) of the silanol group-containing siloxane unit with respect to the total siloxane units. It is preferable to contain about ~ 5 mol%).

Examples of the silanol group-containing siloxane units include (HO) SiO _3/2 units, R ² ′ (HO) SiO _2/2 units, (HO) ₂ SiO _2/2 units, and R ⁴ (HO) SiO _{2 / 2} units, R ⁴ ₂ (HO) SiO _1/2 units, R ³ ′ R ⁴ (HO) SiO _1/2 units, R ⁴ (HO) ₂ SiO _1/2 units (where R ² ′ and R ³ 'Is a group as defined above for R ² and R ³ other than a hydroxyl group, and R ⁴ is as defined above.
Note that the hydroxyl groups in R ^1, R ² and R ^3, means a hydroxyl group in the silanol-containing siloxane units.

  It is preferable that the silanol group-containing siloxane unit is contained within the above range because adhesion to substrates such as ITO, silicon wafer, metal, and resin is improved.

As the structural ratio of the structure of the organopolysiloxane (A), for example, (PhSiO _3/2 ) _x1 (Me ₂ SiO _2/2 ) _m1 (Me ₂ ViSiO _1/2 ) _y1 , (PhSiO _3/2 ) _x1 ( Me ₂ SiO _2/2 ) _m1 (MeViSiO _2/2 ) _y1 , (PhSiO _3/2 ) _x1 (Me ₂ SiO _2/2 ) _m2 (Ph ₂ SiO _2/2 ) _m3 (Me ₂ ViSiO _1/2 ) _y1 , (PhSiO _3/2 ) _x1 (Me ₂ SiO _2/2 ) _m2 (MePhSiO _2/2 ) _m3 (Me ₂ ViSiO _1/2 ) _y1 , (HOSiO _3/2 ) _x1 (Me ₂ SiO _2/2 ) _{m1 (Me 2 ViSiO 1/2) y1 (} PhSiO 3/2) x1 (Me 2 SiO 2/2) m1 (Me (OH) ViSiO 1 / _{) Y1, (HOSiO 3/2) x1} (Me 2 SiO 2/2) m2 (Ph 2 SiO 2/2) m3 (Me 2 ViSiO 1/2) y1, (PhSiO 3/2) x1 (Me 2 SiO 2 _{/ 2) m2 (Ph 2 SiO} 2/2) m3 (Me (HO) ViSiO 1/2) can be exemplified _y1 like.
M1, m2, and m3 are as defined above, and x1 and y1 are positive integers such that x1: m1: y1 or x1: m2 + m3: y1 satisfies 90-24: 75-9: 50-1. X1 + m1 + y1 and x1 + m2 + m3 + y1 are 100.

-(B) Resin-structured organohydrogenpolysiloxane-
An organohydrogenpolysiloxane having a resin structure (that is, a three-dimensional network structure), which is an important component (B) of the composition of the present invention, has R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² , and R ³ are as described above, c is 0, 1 or 2, and d is 1) Or 2 and c + d is 2 or 3.
A structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions is 10 to 50, preferably 15 to 45, more preferably 20 to 35, is partially Is an organopolysiloxane having a resin structure.

When the number of R ² ₂ SiO _2/2 units is 9 or less, the composition has no plasticity, the handling property is poor, or the sheet-like cured product is obtained when the present composition is cured. However, since it will be in a very weak state and it will become difficult to maintain a sheet shape, it is not preferable. Moreover, when the R ² ₂ SiO _2/2 unit exceeds 50, the composition cannot maintain a solid or semi-solid state, or the sheet-like cured product becomes very soft. , Handling and workability deteriorate, which is not preferable.

The structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions is 10 to 50 means that the component (B) At least a part of the R ² ₂ SiO _2/2 units present in, preferably 50 mol% or more (50 to 100 mol%), particularly 80 mol% or more (80 to 100 mol%) of the component (B) It means that a linear diorganopolysiloxane chain structure represented by the general formula (1) is formed in the molecule.

In the molecule of component (B), the R ² ₂ SiO _2/2 unit works to stretch the polymer molecule in a straight line, and the R ¹ SiO _3/2 unit branches the polymer molecule or forms a three-dimensional network. Let The hydrogen atom bonded to silicon in the R ³ _c H _d SiO _{(4-cd) / 2} unit undergoes a hydrosilylation addition reaction with the alkenyl group of the component (A) described above, whereby the composition of the present invention. Plays a role in curing.

(B) The molar ratio of the three essential siloxane units constituting the component, that is, R ¹ SiO _3/2 units: R ² ₂ SiO _2/2 units: R ³ _c H _d SiO _{(4-cd) /} The molar ratio of the _two units is preferably 90 to 24:75 to 9:50 to 1, particularly 70 to 28:70 to 20:10 to 2 (however, 100 in total) from the viewpoint of the properties of the cured product obtained. .

  In addition, the weight average molecular weight in terms of polystyrene by GPC of the component (B) is in the range of 3,000 to 1,000,000, particularly 10,000 to 100,000. From the point of view, it is preferable.

  Such a resin-structured organohydrogenpolysiloxane is a combination of compounds that are raw materials for each unit such that the three siloxane units in the resulting polymer have the required molar ratio, for example, the presence of a catalyst such as an acid. Can be synthesized by co-hydrolysis under.

Here, examples of the raw material of the R ¹ SiO _3/2 unit include MeSiCl ₃ , EtSiCl ₃ , PhSiCl ₃ , n-propyltrichlorosilane, cyclohexyltrichlorosilane, and alkoxysilane such as methoxysilane corresponding to each chlorosilane. it can.

（ここで、ｍ１＝８〜４８の整数（平均値）、ｍ２＝５〜４８の整数（平均値）、ｎ＝０〜４３の整数（平均値）、ただし、ｍ２＋ｍ３＝８〜４８の整数）
等を例示することができる。 As a raw material of R ² ₂ SiO _2/2 unit,

(Where m1 = integer (average value) of 8-48, m2 = integer of 5-48 (average value), n = 0-43 (average value), but m2 + m3 = integer of 8-48
Etc. can be illustrated.

Also, R ³ _c H _d SiO _{(4-cd) / 2} unit is R ³ HSiO _2/2 unit, R ³ ₂ HSiO _1/2 unit, H ₂ SiO _2/2 unit, R ³ H ₂ SiO. It shows that it is an arbitrary combination of one type or two or more types of siloxane units selected from _½ units, and the raw materials thereof include chlorosilanes such as Me ₂ HSiCl, MeHSiCl ₂ , Ph ₂ HSiCl, PhHSiCl _{2, and the} like Examples include alkoxysilanes such as methoxysilanes corresponding to these chlorosilanes.

In the present invention, when the organohydrogenpolysiloxane of component (B) is produced by co-hydrolysis and condensation of the above raw material compounds, the resulting organopolysiloxane of component (B) is added to R ¹ SiO _3. A siloxane unit having a silanol group may be contained in the _{/ 2} unit, R ² ₂ SiO _2/2 unit and / or R ³ _c H _d SiO _{(4-cd) / 2} unit. The organohydrogenpolysiloxane of component (B) is usually 10 mol% or less (0.1 to 10 mol%), preferably 5 mol% or less (0 mol%) of the silanol group-containing siloxane unit based on the total siloxane units. About 1 to 5 mol%).

Examples of the silanol group-containing siloxane unit include (HO) SiO _3/2 units, R ² ′ (HO) SiO _2/2 units, (HO) ₂ SiO _2/2 units, and H (HO) SiO _{2/2. units,} H 2 _{(HO) SiO 1/2 ^{units, R 3 'H (HO)}} SiO 1/2 _units, H (HO) _{2 SiO 1/2} units (wherein, ^{R 2'} and ^{R 3} 'are other than hydroxyl Group as defined above for R ² and R ³ ).
Note that the hydroxyl groups in R ^1, R ² and R ^3, means a hydroxyl group in the silanol-containing siloxane units.

  It is preferable that the silanol group-containing siloxane unit is contained within the above range because adhesion to substrates such as ITO, silicon wafer, metal, and resin is improved.

As the structural ratio of the structure of the organopolysiloxane (B), for example, (PhSiO _3/2 ) _x2 (Me ₂ SiO _2/2 ) _m1 (Me ₂ HSiO _1/2 ) _y2 , (PhSiO _3/2 ) _x2 ( Me ₂ SiO _2/2 ) _{m 1} (MeHSiO _2/2 ) _{y 2} , (PhSiO _3/2 ) _{x 2} (Me ₂ SiO _2/2 ) _{m 2} (Ph ₂ SiO _2/2 ) _{m 3} (Me ₂ HSiO _1/2 ) _{y 2} , (PhSiO _3/2 ) _{x 2} (Me ₂ SiO _2/2 ) _{m 2} (MePhSiO _2/2 ) _{m 3} (Me ₂ HSiO _1/2 ) _{y 2} , (HOSiO _3/2 ) _{x 2} (Me ₂ SiO _2/2 ) _{m1 (Me 2 HSiO 1/2) y2 (} PhSiO 3/2) x2 (Me 2 SiO 2/2) m1 (Me (OH) HSiO 1/2) y2, _{HOSiO 3/2) x2 (Me 2 SiO} 2/2) m2 (Ph 2 SiO 2/2) m3 (Me 2 HSiO 1/2) y2, (PhSiO 3/2) x2 (Me 2 SiO 2/2) m2 (Ph ₂ SiO _2/2 ) _m3 (Me (HO) HSiO _1/2 ) _{y2 and the} like can be exemplified.
M1, m2, and m3 are as defined above, and x2 and y2 are positive integers such that x2: m1: y2 or x2: m2 + m3: y2 satisfies 90-24: 75-9: 50-1. X2 + m1 + y2 and x2 + m2 + m3 + y2 are 100.

  The blending amount of the organohydrogenpolysiloxane of component (B) is the molar ratio of hydrogen atoms (SiH groups) bonded to silicon atoms in component (B) relative to the total amount of vinyl groups and allyl groups in component (A). The amount is 0.1 to 4.0, particularly preferably 0.5 to 3.0, and more preferably 0.8 to 2.0. When the curing reaction proceeds well at 0.1 or more and a silicone cured product can be obtained, and 4.0 or less, the amount of unreacted (residual) SiH groups in the cured product becomes small, and the physical properties of the cured product are deteriorated over time. This is preferable because there is no fear of change.

-(C) Platinum group metal catalyst-
This catalyst component is blended in order to promote the addition curing reaction of the composition of the present invention, and there are platinum-based, palladium-based and rhodium-based ones. As the catalyst, any conventionally known catalyst for promoting the hydrosilylation reaction can be used. In consideration of cost and the like, platinum-based materials such as platinum, platinum black, and chloroplatinic acid, such as H ₂ PtCl ₆ · nH ₂ O, K ₂ PtCl ₆ , KHPtCl ₆ · nH ₂ O, K ₂ PtCl ₄ , K ₂ PtCl ₄ · nH ₂ O, PtO ₂ · nH ₂ O, (where n is a positive integer), etc., and complexes thereof with hydrocarbons such as olefins, alcohols, or vinyl group-containing organopolysiloxanes Etc. can be illustrated. These catalysts can be used singly or in combination of two or more.

  The compounding amount of the component (C) may be an effective amount for curing, and is usually 0.1 to 500 ppm in terms of mass as a platinum group metal with respect to the total amount of the component (A) and the component (B). Preferably it is used in the range of 0.5 to 100 ppm.

-(D) Conductive filler-
The conductive filler of component (D) is not particularly limited as long as it does not react with other components in the present composition and stable thermal conductivity and electrical conductivity are ensured. For example, various metals such as gold powder, silver powder, copper powder, nickel powder, carbon powder and alloys thereof, silica, alumina, organic resin, and powders made of an insulating material such as silicone rubber, the various metals described above. The powder which carried out vapor deposition or plating is mentioned, These can be used individually by 1 type or in mixture of 2 or more types.

  The range of 100-1500 mass parts is preferable normally with respect to 100 mass parts of all the components (A)-(C), and the range of 400-1000 mass parts is more preferable.

  The conductive filler of component (D), for example, as a particle size range in particle size distribution measurement by a laser beam diffraction method such as a cirrus laser measuring device, usually has a particle size of 10 nm or more, preferably 10 nm. One having a thickness of about 100 μm, more preferably about 100 nm to 50 μm is used.

  Among these, as the conductive filler of component (D), those having an electrical resistivity at 20 ° C. of 0.1 Ω · m or less are preferred, and silver (silver powder) is more preferred.

-Other ingredients-
In addition to the components (A) to (D) described above, various additives known per se can be blended with the composition of the present invention as necessary.

・ Inorganic filler:
Examples include reinforcing inorganic fillers such as fumed silica and fumed titanium dioxide, and non-reinforcing inorganic fillers such as calcium carbonate, calcium silicate, titanium dioxide, ferric oxide, carbon black, and zinc oxide. it can. These inorganic fillers can be appropriately blended in the range of 600 parts by mass or less (0 to 600 parts by mass) per 100 parts by mass in total of the components (A) and (B).

・ Adhesion aid:
Moreover, in order to provide adhesiveness to the composition of this invention, an adhesion assistant can be added as needed. Examples of the adhesion assistant include a hydrogen atom (SiH group) bonded to a silicon atom in one molecule, an alkenyl group (for example, Si—CH═CH ₂ group) bonded to a silicon atom, and an alkoxysilyl group (for example, trimethoxysilyl). Group) and an epoxy group (for example, glycidoxypropyl group, 3,4-epoxycyclohexylethyl group) a linear or cyclic silicon atom containing at least two, preferably two or three functional groups 4 to 50, preferably about 4 to 20 organosiloxane oligomers, organooxysilyl-modified isocyanurate compound represented by the following general formula (2) and / or hydrolysis condensate thereof (organosiloxane-modified isocyanurate compound) Etc.

〔式中、Ｒ^５は、下記式（３）

（ここで、Ｒ^６は水素原子又は炭素原子数１〜８の一価炭化水素基であり、ｖは１〜６、特に１〜４の整数である。）
で表される有機基、又は脂肪族不飽和結合を含有する一価炭化水素基であるが、Ｒ^５の少なくとも１個は上記式（３）の有機基である。〕

[Wherein R ⁵ represents the following formula (3)

(Here, R ⁶ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, and v is an integer of 1 to 6, particularly 1 to 4.)
Or a monovalent hydrocarbon group containing an aliphatic unsaturated bond, at least one of R ⁵ is an organic group of the above formula (3). ]

The monovalent hydrocarbon group containing an aliphatic unsaturated bond represented by R ⁵ in the general formula (2) includes a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a pentenyl group, and a hexenyl group. C2-C8 cycloalkenyl groups, such as C2-C8 alkenyl groups, especially cyclohexenyl groups, and the like. Examples of the monovalent hydrocarbon group for R ⁶ in the above formula (3) include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include alkyl groups such as cyclohexyl groups, alkenyl groups and cycloalkenyl groups exemplified for R ⁵ above, and monovalent hydrocarbon groups having 1 to 8 carbon atoms, particularly 1 to 6 carbon atoms such as aryl groups such as phenyl groups, An alkyl group is preferred.

（式中、ｇ及びｈは各々０〜５０の範囲の正の整数であって、しかもｇ＋ｈが２〜５０、好ましくは４〜２０を満足するものである。） Furthermore, examples of the adhesion assistant include compounds represented by the following formula.

(In the formula, g and h are each a positive integer in the range of 0 to 50, and g + h satisfies 2 to 50, preferably 4 to 20.)

  Among the above-mentioned organosilicon compounds, compounds having particularly good adhesion to the resulting cured product have a silicon atom-bonded alkoxy group and an alkenyl group or silicon atom-bonded hydrogen atom (SiH group) in one molecule. It is an organosilicon compound.

  The compounding amount of the adhesion assistant is usually 10 parts by mass or less (that is, 0 to 10 parts by mass), preferably 0.1 to 8 parts by mass, more preferably 0.2 to 100 parts by mass of the component (A). About 5 parts by mass can be blended. If it is 10 parts by mass or less, the hardness of the cured product will not be adversely affected and the surface will not be tacky.

  Further, if necessary, the addition-curable silicone resin composition of the present invention maintains a solid or semi-solid at room temperature, and a liquid silicone component can be added to such an extent that it does not become liquid. As such a liquid silicone component, those having a viscosity of about 1 to 100,000 mPa · s at room temperature (25 ° C.) are preferable, and examples thereof include vinyl siloxane, hydrogen siloxane, alkoxy siloxane, hydroxy siloxane, and mixtures thereof. The addition amount is a condition that the addition-curable silicone resin composition maintains a solid or semi-solid at room temperature, and is usually 50% by mass or less based on the entire addition-curable silicone resin composition.

・ Curing inhibitor:
In the composition of the present invention, a curing inhibitor can be appropriately blended as necessary for the purpose of adjusting the curing rate. Examples of the curing inhibitor include high vinyl group-containing organopolysiloxanes such as tetramethyltetravinylcyclotetrasiloxane and hexavinyldisiloxane, triallyl isocyanurate, alkyl maleates, acetylene alcohols and their silane-modified products and siloxanes. Examples thereof include compounds selected from the group consisting of modified products, hydroperoxides, tetramethylethylenediamine, benzotriazole, and mixtures thereof. The curing inhibitor is usually added in an amount of 0.001 to 1.0 part by mass, preferably 0.005 to 0.5 part by mass per 100 parts by mass of the component (A).

-Silane coupling agent In order to improve the dispersibility to resin, the electroconductive powder of this invention can be processed with a silane coupling agent. As a silane coupling agent, a compound represented by the following general formula (A),
R ⁷ Si (OR ⁸ ) ₃ (A)
(Here, R ⁷ is an aliphatic alkyl group, and R ⁸ is a methyl group or an ethyl group.)
It _{consists of} R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , and R ³ Independently represents a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, or a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, a is 0, 1 or 2, and b is 1 or 2 And a + b is 2 or 3.)
A polysiloxane comprising a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated, the number of repetitions of which is 5 to 50, and the terminal is blocked with ₃ units of Si (OR ⁸ ) (Here, R ⁸ is the same as above.)
Is mentioned.

  A typical example of the composition of the present invention is a composition substantially composed of the components (A) to (D). Here, “consisting essentially of the components (A) to (D)” means that the composition comprises at least one of the above-mentioned optional components other than the components (A) to (D) according to the purpose, etc. It means that it can be included if necessary.

-Preparation-
The addition-curable silicone resin composition of the present invention is prepared by uniformly mixing required components. Usually, it is stored at a low temperature in a refrigerator or a freezer so that the curing does not proceed, and it is cured immediately by heating when necessary.

[Silicone resin composition sheet]
The composition sheet of the present invention is a sheet comprising the above-described addition-curable silicone resin composition, and the thickness is usually 1 to 500 μm, preferably 10 to 300 μm. The thickness and the content of the conductive powder are appropriately adjusted depending on the application.

  The composition sheet of the present invention is processed into a sheet shape and then stored, for example, frozen. And it can harden | cure immediately by heating when needed, and can form the flexible cured resin layer without high hardness and surface tack.

Examples of means for processing the composition of the present invention into a sheet include a film coater and a hot press. In order to process the composition into a sheet using these means, for example, the composition is sandwiched between a pressurizing base film and a release film, and usually 60 to 120 ° C., preferably 70, using a hot press machine. Compression molding is performed at a temperature of -100 ° C. under a pressure of 0.5 to 10 t / cm ² , preferably 1 to 7 t / cm ² for 1 to 30 minutes, preferably 2 to 10 minutes.

  Examples of the base film for pressurization include PET film, fluorine resin film, polyethylene film, polypropylene film, and examples of the release film include PET film coated with fluorine resin, PET film coated with silicone resin, fluorine resin film, and the like. Can be mentioned.

  The composition of the present invention and the composition sheet formed as described above are easy to handle because they are solid or semi-solid at room temperature. In addition, since the conductive filler is uniformly dispersed, the electrical conductivity is good, so that it is useful as an electrode material for solar cells or a die attach material for semiconductor elements. In particular, when the composition sheet is used as a die attach material, handling is easier and workability is better.

  As a method of using the composition sheet as a die attach material, any one of a method of first separating the sheet and then incorporating it into a semiconductor device or the like, and a method of pasting the sheet on a silicon wafer or the like and then individualizing the entire wafer. But it ’s okay. Note that the heat curing step may be performed before or after the individualization step.

  Curing of the composition sheet of the present invention is usually performed at a temperature of 50 to 200 ° C., particularly 70 to 180 ° C., and the heating time may be 1 to 30 minutes, particularly about 2 to 10 minutes. Further, secondary curing (post-cure) can be performed, and the temperature for this is usually 50 to 200 ° C., particularly 70 to 180 ° C., and the time may be 0.1 to 10 hours, particularly 1 to 4 hours. Usually, secondary curing is performed after primary curing.

  The sheet-like cured product obtained by curing the silicone resin composition sheet has the advantage that it is a hard resin, has excellent flexibility, has little surface tack, and can be easily molded by a conventional molding apparatus. is there.

  In addition, the sheet-like cured product has the advantage that the conductive filler is uniformly dispersed therein, and the stability of the dispersibility is high, so that it can be used as an electrode material for solar cells or a die attach material for semiconductor elements. Useful.

  As a method of using the sheet-like cured product as a die attach material, any one of a method in which a sheet is first separated and then placed on a semiconductor device, or a method in which a sheet is bonded to a silicon wafer or the like and then the wafer is separated into pieces. But it ’s okay.

  EXAMPLES Hereinafter, although a synthesis example, a preparation example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. Ph represents a phenyl group, Me represents a methyl group, and Vi represents a vinyl group.

The weight average molecular weight mentioned in the present invention refers to a weight average molecular weight using polystyrene as a standard substance by gel permeation chromatography (GPC) measured under the following conditions.
[Measurement condition]
Developing solvent: THF
Flow rate: 0.6mL / min
Detector: Differential refractive index detector (RI)
Column: TSK Guardcolom SuperH-L
TSKgel SuperH4000 (6.0 mm ID × 15 cm × 1)
TSKgel Super H3000 (6.0 mm ID × 15 cm × 1)
TSKgel SuperH2000 (6.0 mm ID × 15 cm × 2)
(Both manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Sample injection volume: 20 μL (0.5% by mass THF solution)

[Synthesis Example 1]
-Vinyl group-containing organopolysiloxane resin (A1)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₂₃ SiMe ₂ Cl: 1 mol, Me ₂ ViSiCl: 6 mol was dissolved in a toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A1).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₂₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27. [—SiMe ₂ O— (Me ₂ SiO) ₂₃ —SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.06 This resin had a weight average molecular weight of 65,000 and a melting point of 58 ° C.

[Synthesis Example 2]
-Hydrosilyl group-containing organopolysiloxane resin (B1)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₂₃ SiMe ₂ Cl: 1 mol, Me ₂ HSiCl: 6 mol dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B1).

This resin has a constitutional ratio of a siloxane unit constituting and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₂₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 23 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.06. This resin had a weight average molecular weight of 56,000 and a melting point of 56 ° C.

[Synthesis Example 3]
-Vinyl group-containing organopolysiloxane resin (A2)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₂₃ SiMe ₂ Cl: 1 mol, MeViSiCl ₂ : 3 mol was dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, alkali After neutralization and dehydration by washing, the solvent was stripped to synthesize a vinyl group-containing resin (A2).

This resin has a constitutional ratio of a siloxane unit constituting and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₂₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ -SiMe ₂ O- (Me ₂ SiO) ₂₃ -SiMe ₂ O _2/2 ] _0.01 [MeViSiO _2/2 ] _0.03 . This resin had a weight average molecular weight of 62,000 and a melting point of 60 ° C.

[Synthesis Example 4]
-Hydrosilyl group-containing organopolysiloxane resin (B2)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₂₃ SiMe ₂ Cl: 1 mol, MeHSiCl ₂ : 3 mol were dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, alkali After neutralization and dehydration by washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B2).

This resin has a constitutional ratio of a siloxane unit constituting and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₂₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ -SiMe ₂ O- (Me ₂ SiO) ₂₃ -SiMe ₂ O _2/2 ] _0.01 [MeHSiO _2/2 ] _0.03 . This resin had a weight average molecular weight of 58,000 and a melting point of 58 ° C.

[Synthesis Example 5]
-Vinyl group-containing organopolysiloxane resin (A3)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₃₃ SiMe ₂ Cl: 1 mol, Me ₂ ViSiCl: 3 mol was dissolved in a toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A3).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₃₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 33 -SiMe 2 O 2/2] 0.01 [Me 2 ViSiO 1/2] 0.03. This resin had a weight average molecular weight of 63,000 and a melting point of 63 ° C.

[Synthesis Example 6]
-Hydrosilyl group-containing organopolysiloxane resin (B3)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₃₃ SiMe ₂ Cl: 1 mol, Me ₂ HSiCl: 3 mol dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B3).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₃₃ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 33 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.03. This resin had a weight average molecular weight of 57,000 and a melting point of 56 ° C.

[Synthesis Example 7]
-Vinyl group-containing organopolysiloxane resin (A4)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₈ SiMe ₂ Cl: 1 mol, Me ₂ ViSiCl: 6 mol dissolved in toluene solvent, dropped into water, cohydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A4).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₈ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27. [—SiMe ₂ O— (Me ₂ SiO) ₈ —SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.06 . This resin had a weight average molecular weight of 45,000 and a melting point of 56 ° C.

[Synthesis Example 8]
-Hydrosilyl group-containing organopolysiloxane resin (B4)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₈ SiMe ₂ Cl: 1 mol, Me ₂ HSiCl: 6 mol dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B4).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₇ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 8 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.06. This resin had a weight average molecular weight of 42,000 and a melting point of 60 ° C.

[Synthesis Example 9]
-Vinyl group-containing organopolysiloxane resin (A5)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₄₈ SiMe ₂ Cl: 1 mol, Me ₂ ViSiCl: 6 mol was dissolved in a toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A4).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₈ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27. [—SiMe ₂ O— (Me ₂ SiO) ₄₈ —SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.06 . This resin had a weight average molecular weight of 60,000 and a melting point of 62 ° C.

[Synthesis Example 10]
-Hydrosilyl group-containing organopolysiloxane resin (B5)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₄₈ SiMe ₂ Cl: 1 mol, Me ₂ HSiCl: 6 mol were dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B4).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₇ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 48 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.06. This resin had a weight average molecular weight of 58,000 and a melting point of 54 ° C.

[Comparative Synthesis Example 1]
-Vinyl group-containing organopolysiloxane resin (A4)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₇ SiMe ₂ Cl: 1 mol, Me ₂ ViSiCl: 6 mol was dissolved in a toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A4).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₇ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27. [—SiMe ₂ O— (Me ₂ SiO) ₇ —SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.06 . This resin had a weight average molecular weight of 45,000 and a melting point of 56 ° C.

[Comparative Synthesis Example 2]
-Hydrosilyl group-containing organopolysiloxane resin (B4)-
Organosilane represented by PhSiCl ₃ : 27 mol, ClMe ₂ SiO (Me ₂ SiO) ₇ SiMe ₂ Cl: 1 mol, Me ₂ HSiCl: 6 mol dissolved in toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B4).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₇ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 7 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.06. This resin had a weight average molecular weight of 42,000 and a melting point of 54 ° C.

[Comparative Synthesis Example 3]
-Vinyl group-containing organopolysiloxane resin (A5)-
Organosilane represented by PhSiCl ₃ : 27 mol, HOMe ₂ SiO (Me ₂ SiO) ₉₈ SiMe ₂ OH: 1 mol, Me ₂ ViSiCl: 6 mol dissolved in a toluene solvent, dropped into water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A5).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₉₈ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27. [—SiMe ₂ O— (Me ₂ SiO) ₉₈ —SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.06 . This resin was in the form of a paste having a weight average molecular weight of 64,000.

[Comparative Synthesis Example 4]
-Hydrosilyl group-containing organopolysiloxane resin (B5)-
Organosilane represented by PhSiCl ₃ : 27 mol, HOMe ₂ SiO (Me ₂ SiO) ₉₈ SiMe ₂ OH: 1 mol, Me ₂ HSiCl: 6 mol, dissolved in toluene solvent, dropped into water, cohydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B5).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₉₈ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 98 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.06. This resin was in the form of a paste having a weight average molecular weight of 62,000.

[Comparative Synthesis Example 5]
-Vinyl group-containing organopolysiloxane resin (A8)-
Organosilane represented by PhSiCl ₃ : 27 mol, HOMe ₂ SiO (Me ₂ SiO) ₄₉ SiMe ₂ OH: 1 mol, Me ₂ ViSiCl: 6 mol dissolved in a toluene solvent, dropped into water, cohydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a vinyl group-containing resin (A8).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₉₈ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27. [—SiMe ₂ O— (Me ₂ SiO) ₄₉ —SiMe ₂ O _2/2 ] _0.01 [Me ₂ ViSiO _1/2 ] _0.06 . This resin was in the form of a paste having a weight average molecular weight of 64,000.

[Comparative Synthesis Example 6]
-Hydrosilyl group-containing organopolysiloxane resin (B8)-
Organosilane represented by PhSiCl ₃ : 27 mol, HOMe ₂ SiO (Me ₂ SiO) ₄₉ SiMe ₂ OH: 1 mol, Me ₂ HSiCl: 6 mol are dissolved in a toluene solvent, then dropped in water, co-hydrolyzed, further washed with water, After neutralization and dehydration by alkali washing, the solvent was stripped to synthesize a hydrosilyl group-containing resin (B8).

This resin has a constitutional ratio of a siloxane unit and a structure represented by [—SiMe ₂ O— (Me ₂ SiO) ₉₈ —SiMe ₂ O _2/2 ] represented by the formula: [PhSiO _3/2 ] _0.27 [ represented by _{-SiMe 2 O- (Me 2 SiO)} 49 -SiMe 2 O 2/2] 0.01 [Me 2 HSiO 1/2] 0.06. This resin was in the form of a paste having a weight average molecular weight of 62,000.

[Preparation Example 1]
Vinyl group-containing resin (A1) obtained in Synthesis Example 1: 189 g, hydrosilyl group-containing resin (B1) obtained in Synthesis Example 2: 189 g, acetylene alcohol-based ethynylcyclohexanol as a reaction inhibitor: 0.2 g, Octyl alcohol modified solution of chloroplatinic acid: 0.1 g was added to prepare a base composition. After adding 76 parts by mass of silver powder (AgC-237; manufactured by Fukuda Metal Foil Powder Industry) to 10 parts by mass of the base composition, the mixture was thoroughly stirred with a planetary mixer heated to 60 ° C., and the silver-containing silicone Resin composition 1 was prepared. Composition 1 was a plastic solid at 25 ° C.

  The composition 1 thus obtained was subjected to the following measurements and evaluated.

[Example 1]
1) Volume resistance measurement The composition 1 is sandwiched between a PET film (pressing base film) and a fluororesin-coated PET film (peeling film), and a pressure of 5 t / cm ² at 80 ° C. using a hot press machine. The film was compression-molded for 5 minutes to form a film having a thickness of 50 μm. Further, this was heated and cured at 150 ° C. for 4 hours, and the volume resistance of the cured product was measured using a four-terminal method.

2) Evaluation of mechanical properties Composition 1 was compression-molded with a compression molding machine and heat-molded at 150 ° C for 5 minutes to obtain a cured product. Furthermore, about this which was secondarily cured at 150 ° C. for 4 hours, in accordance with JIS K 6251 and JIS K 6253, tensile strength (0.2 mm thickness), hardness (using a type D spring tester) Measurement) and elongation at break (0.2 mm thickness) were measured.

3) Evaluation of surface tackiness Similar to the evaluation of the mechanical properties described above, the tackiness of the cured surface of the cured product was confirmed by touch.

4) Evaluation of dispersion stability The composition 1 immediately after preparation was put into a recess having a diameter of 6 mm and a center depth of 2 mm formed on an alumina substrate, and the thickness was obtained by heating and curing as in the case of the evaluation of the mechanical properties. A disk-shaped molded product having a diameter of 2 mm and a diameter of 6 mm was formed. A part of each of the upper surface layer (a layer having a thickness of 0.5 mm from the upper surface) and the lower surface layer (a layer having a thickness of 0.5 mm from the lower surface) is cut out from each of the molded products. By heating and ashing, the content (mass%) of silver powder in the obtained ash was measured, and the contents in the upper part and the lower part were compared.

  Furthermore, after the composition 1 was stored in a freezer at −20 ° C. for 3 months, it was molded in the same manner as described above, and the silver powder content in the upper part and the lower part was compared in the same manner. Thus, the dispersion stability of the silver powder was measured.

  Table 1 shows the measurement results of the evaluation items 1) to 4).

[Preparation Example 2]
Vinyl group-containing resin (A-2) obtained in Synthesis Example 3 instead of vinyl group-containing resin (A-1): 189 g, obtained in Synthesis Example 4 instead of hydrosilyl group-containing resin (B-1) A silver-containing silicone resin composition 2 was prepared in the same manner as in Preparation Example 1, except that 189 g of hydrosilyl group-containing resin (B-2) was used. Composition 2 was a plastic solid at 25 ° C.

[Example 2]
The composition 2 obtained in Preparation Example 2 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Preparation Example 3]
Vinyl group-containing resin (A-3) obtained in Synthesis Example 5 instead of vinyl group-containing resin (A-1): 189 g, obtained in Synthesis Example 6 instead of hydrosilyl group-containing resin (B-1) Silver-containing silicone resin composition 3 was prepared in the same manner as in Preparation Example 1, except that 189 g of hydrosilyl group-containing resin (B-3) was used. Composition 3 was a plastic solid at 25 ° C.

[Example 3]
The composition 3 obtained in Preparation Example 3 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Preparation Example 4]
189 g of the vinyl group-containing resin (A-4) obtained in Synthesis Example 7 instead of the vinyl group-containing resin (A-1), and obtained in Synthesis Example 8 instead of the hydrosilyl group-containing resin (B-1). A silver-containing silicone resin composition 4 was prepared in the same manner as in Preparation Example 1, except that 189 g of hydrosilyl group-containing resin (B-4) was used. Composition 4 was a plastic solid at 25 ° C.

[Example 4]
The composition 4 obtained in Preparation Example 4 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Preparation Example 5]
Instead of vinyl group-containing resin (A-1), vinyl group-containing resin (A-5) obtained in Synthesis Example 9: 189 g, obtained in Synthesis Example 10 instead of hydrosilyl group-containing resin (B-1) Silver-containing silicone resin composition 5 was prepared in the same manner as in Preparation Example 1, except that 189 g of hydrosilyl group-containing resin (B-5) was used. Composition 4 was a plastic solid at 25 ° C.

[Example 5]
The composition 5 obtained in Preparation Example 5 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Preparation Example 6]
Vinyl group-containing resin (A-6) obtained in Comparative Synthesis Example 1 instead of vinyl group-containing resin (A-1): 189 g, obtained in Comparative Synthesis Example 2 instead of hydrosilyl group-containing resin (B-1) Silver-containing silicone resin composition 6 was prepared in the same manner as in Preparation Example 1, except that 189 g of the obtained hydrosilyl group-containing resin (B-6) was used. This composition 6 was solid at 25 ° C., but had no plasticity.

[Comparative Example 1]
The composition 6 obtained in Preparation Example 6 was evaluated in the same manner as in Example 1. However, the cured product was very fragile and could not be evaluated because the shape could not be maintained.

[Preparation Example 7]
Vinyl group-containing resin (A-7) obtained in Comparative Synthesis Example 3 instead of vinyl group-containing resin (A-1): 189 g, obtained in Comparative Synthesis Example 4 instead of hydrosilyl group-containing resin (B-1) A silver-containing silicone resin composition 7 was prepared in the same manner as in Preparation Example 1, except that 189 g of the obtained hydrosilyl group-containing resin (B-7) was used. The composition 7 was pasty at 25 ° C. and could not retain its shape.

[Comparative Example 2]
The composition 7 obtained in Preparation Example 7 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Preparation Example 8]
Vinyl group-containing resin (A-7) obtained in Comparative Synthesis Example 3 instead of vinyl group-containing resin (A-1): 189 g, obtained in Comparative Synthesis Example 4 instead of hydrosilyl group-containing resin (B-1) Silver-containing silicone resin composition 8 was prepared in the same manner as in Preparation Example 1, except that 189 g of the obtained hydrosilyl group-containing resin (B-7) was used. This composition 8 was pasty at 25 ° C. and could not retain its shape.

[Comparative Example 3]
The composition 8 obtained in Preparation Example 8 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4]
In Preparation Example 1, instead of 10 parts by mass of the base composition, KJR-632 (trade name, Shin-Etsu Chemical Co., Ltd.), a commercially available addition reaction curable silicone varnish mainly composed of a vinyl group-containing organopolysiloxane resin that is liquid at room temperature. A silver-containing silicone resin composition 9 (liquid at 25 ° C.) was prepared in the same manner as Preparation Example 1 except that 10 parts by mass was used.
About this composition 9, it carried out similarly to Example 1, and evaluated each characteristic. The results are shown in Table 1.

[Comparative Example 5]
In Preparation Example 1, instead of 10 parts by mass of the base composition, KJR-632L-1 (trade name, Shin-Etsu) is a commercially available addition reaction curable silicone varnish mainly composed of a vinyl group-containing organopolysiloxane resin that is liquid at room temperature. A silver-containing silicone resin composition 10 (liquid at 25 ° C.) was prepared in the same manner as in Preparation Example 1, except that 10 parts by mass of Chemical Industry Co., Ltd. was used.
About this composition 10, it carried out similarly to Example 1, and evaluated each characteristic. The results are shown in Table 1.

As shown in Table 1, the conductive addition-curable silicone resin composition shown in the present invention (in which the number of repeating R ² SiO _2/2 units is in the range of 10 to 50: Examples 1 to 5 ) Is solid at room temperature, the handling property and the stability of the dispersibility of the conductive filler made of silver powder are good. Moreover, since the cured sheet-like product has no surface tack and low volume resistance, the electrical conductivity is good.
On the other hand, in Comparative Example 1 in which the number of repeating R ² SiO _2/2 units is 9, the cured product is very brittle, and Comparative Examples 2 and 3 exceeding 50 have a surface on the cured sheet-like cured product. I was able to tack. In Comparative Examples 4 and 5, since the composition was liquid at room temperature, it easily settled, and a stable dispersion state of the conductive filler made of silver powder could not be obtained.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Claims (8)

(A) R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _a R ⁴ _b SiO _{(4-ab) / 2} units (where R ¹ , R ² , And R ³ independently represents any of a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, and a phenyl group, R ⁴ independently represents a vinyl group or an allyl group, and a is 0, 1 or 2 , B is 1 or 2, and a + b is 2 or 3.)
An organopolysiloxane having a resin structure including a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50;
(B) R ¹ SiO _3/2 units, R ² ₂ SiO _2/2 units, and R ³ _c H _d SiO _{(4-cd) / 2} units (where R ¹ , R ² and R ³ is independently as described above, c is 0, 1 or 2, d is 1 or 2, and c + d is 2 or 3.
Resin-structured organohydrogenpolysiloxane comprising a structure in which at least a part of the R ² ₂ SiO _2/2 unit is continuously repeated and the number of repetitions thereof is 10 to 50: in the component (A) The amount of hydrogen atoms bonded to silicon atoms in component (B) relative to the total of vinyl groups and allyl groups is 0.1 to 4.0 by molar ratio,
(C) Platinum group metal-based catalyst: an addition-curable silicone resin composition comprising a curing effective amount and (D) a conductive filler, and is solid or semi-solid at room temperature.   The conductive filler of the component (D) is contained in an amount of 100 to 1500 parts by mass with respect to a total of 100 parts by mass of the components (A) to (C). Addition-curable silicone resin composition.   The addition-curable silicone resin composition according to claim 1 or 2, wherein the conductive filler of the component (D) has an electrical resistivity at 20 ° C of 0.1 Ω · m or less.   4. The addition-curable silicone resin composition according to claim 1, wherein the conductive filler of the component (D) is silver.   The silicone resin composition sheet formed by shape | molding the composition as described in any one of Claims 1-4 in a sheet form.   The die-attach material which consists of a composition as described in any one of Claims 1-4.   A sheet-like cured product obtained by curing the silicone resin composition sheet according to claim 5.   The die attach material which consists of a sheet-like hardened | cured material of Claim 7.