JP2019183139A - Manufacturing method of silicone resin composition, and silicone resin composition - Google Patents

Abstract

To provide a manufacturing method of a silicone resin composition capable of manufacturing a high quality cured article, and the silicone resin composition.SOLUTION: There is provided a manufacturing method of a silicone resin composition having a process for stirring a mixture of a silicone resin A and a silicone resin B until satisfying the formula (A). 1.03<Mw/Mw<1.2 (A), wherein Mwis weight average molecular weight of a mixture of the silicone A and the silicone B, and Mwis weight average molecular weight of a product obtained by the process for stirring. Silicone resin A: a silicone resin in which a contained structure unit is practically only a T body, a percentage of a T3 body in the T body is 60 mol% to 90 mol%, and weight average molecular weight is 1500 to 8000. Silicone resin B: a silicone resin in which a contained structure unit is practically only the T body, a percentage of the T3 body in the T body is 30 mol% or more and less than 60 mol%, and weight average molecular weight is 1500 or more.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a silicone resin composition and a silicone resin composition.

  Conventionally, LEDs are used as light sources. As a light source device using an LED as a light source, a configuration is known in which after a LED is attached to a circuit board, a sealing portion that covers the LED is formed with a resin sealing material to protect the LED and the peripheral structure of the LED. ing.

  In recent years, UV (ultraviolet) -LEDs have started to appear on the market. In a light source device using such a UV-LED as a light source, the resin sealing portion is easily deteriorated by the UV light. Therefore, quartz glass may be used for sealing the UV-LED.

  However, since quartz glass is expensive, a low-cost alternative material has been demanded. Moreover, when sealing UV-LED using quartz glass, the obtained light source device becomes a structure in which an air layer exists between UV-LED and quartz glass. In this case, when UV light enters the quartz glass from the air layer, there is a problem that the extraction efficiency of the UV light is low due to the difference in the refractive index at the interface.

  Therefore, it has been proposed to seal the UV-LED with a cured product of a silicone-based resin composition (see, for example, Patent Document 1).

JP 2017-8297 A

  When using the hardened | cured material of a resin composition as a sealing material, it is preferable that the obtained sealing part has high light transmittance, without scattering light. In the light source device in which the LED is sealed with such a sealing portion, the light emitted from the LED can be taken out of the device with high efficiency, and the light emitted from the LED can be effectively used.

  However, when using the hardened | cured material of a resin composition as a sealing material, an external appearance may be impaired by the unevenness | corrugation of the surface of the sealing part obtained, and the bubble mixed in in a sealing part. In such a sealed portion whose appearance is impaired, the light emitted from the LED is reflected and scattered, and it may be difficult to take out the device outside the device with high efficiency. Therefore, there has been a demand for a resin composition that can easily produce a high-quality sealing portion (cured product) having high light transmittance without scattering light.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the manufacturing method and silicone resin composition of a silicone resin composition which can manufacture a high quality hardened | cured material easily.

In order to solve the above-described problems, one aspect of the present invention is a method for producing a silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials, and includes the following silicone resin A and the following silicone resin B: And a method for producing a silicone resin composition comprising a step of stirring the mixture until the following formula (A) is satisfied.
_{1.03 <Mw com / Mw ab <} 1.2 ... (A)
(Mw _ab is the weight average molecular weight of the mixture of the silicone resin A and the silicone resin B, and Mw _com is the weight average molecular weight of the product obtained by the stirring step.)
Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms. T3-form means that all three oxygen atoms of the T-form of the T-form are different from other silicon atoms. It means the structural unit which is connected.)

In order to solve the above-mentioned problem, one aspect of the present invention is a method for producing a silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials, and the silicone resin B is 200 hPa or less. The first step of obtaining a silicone resin B1 having a high molecular weight of the silicone resin B by stirring while heating to 100 ° C. or higher in a reduced pressure environment, and adding the silicone resin A to the silicone resin B1 to obtain a mixture A second step of stirring the mixture while heating to 100 ° C. or higher in a reduced pressure environment of 200 hPa or less, and in the second step, the mixture is stirred until the following formula (A) is satisfied: A method for producing the composition is provided.
1.03 <Mw _com / Mw _ab <1.2 (A)
(Mw _ab is the weight average molecular weight of the mixture of the silicone resin A and the silicone resin B, and Mw _com is the weight average molecular weight of the product obtained in the second step.)
Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms. T3-form means that all three oxygen atoms of the T-form of the T-form are different from other silicon atoms. It means the structural unit which is connected.)

In one aspect of the present invention, in the first step, the silicone resin D containing the silicone resin B1 is stirred while heating the silicone resin B and the following silicone resin C to 100 ° C. or higher in a reduced pressure environment of 200 hPa or less. It is good also as a manufacturing method which obtains.
Silicone resin C: A silicone resin having a mass reduction rate of less than 5% when heated from room temperature to 200 ° C. at a rate of temperature increase of 5 ° C./min and held in air at 200 ° C. for 5 hours.

  In one aspect of the present invention, in the raw material, the mass ratio of the silicone resin A and the silicone resin B is [silicone resin A]: [silicone resin B] = 10: 90 to 60:40. It is good. (Here, [silicone resin A] represents the mass of the silicone resin A, and [silicone resin B] represents the mass of the silicone resin B.)

  In one aspect of the present invention, in the stirring step, the composition containing the mixture may be stirred, and the organic solvent content in the composition may be 1% by mass or less.

  In one aspect of the present invention, the stirring step may be a manufacturing method in which the composition containing the mixture and the reaction promoting catalyst is stirred.

One embodiment of the present invention is a silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials, wherein the horizontal axis is obtained by GPC measurement, the horizontal axis is the molecular weight in terms of standard polystyrene, and the vertical axis is Provided is a silicone resin composition having an evaluation value obtained by the following method of less than 25 based on a molecular weight distribution curve as a detection intensity of a differential refractive index detector.
Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms.
The T3 body means a structural unit in which all three oxygen atoms of the T body in the T body are bonded to other silicon atoms. )
(Method)
In the molecular weight distribution curve, the vertical axis of the molecular weight distribution curve has a peak top intensity of −1 with respect to a peak having a maximum absolute value among peaks having an intensity of less than 0 and having a molecular weight in the range of 245 to 400. Normalize the value of. Surrounded by the normalized molecular weight distribution curve and a straight line (reference line) represented by a linear expression connecting two points of a molecular weight of 140 and a point of 245 in the normalized molecular weight distribution curve The sum of the normalized detection intensity values in the determined area is obtained as the evaluation value.
(The normalized detection intensity value in the region surrounded by the reference line and the normalized molecular weight distribution curve is determined from the reference line at each molecular weight lined up with a molecular weight interval corresponding to a data acquisition time interval of GPC measurement of 0.3 seconds. It means a value obtained by subtracting the normalized detection intensity value.)

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method and silicone resin composition of a silicone resin composition which can manufacture a high quality hardened | cured material easily can be provided.

2 is an appearance photograph of a cured product obtained by curing the silicone resin composition 1 of Example 1. FIG. 2 is an appearance photograph of a cured product obtained by curing the silicone resin composition 5 of Comparative Example 1.

[Method for producing silicone resin composition]
Hereinafter, after explaining each component used for the manufacturing method of the silicone resin composition of this embodiment, the manufacturing method of a silicone resin composition is demonstrated in detail.
In the following description, a composition obtained by the method for producing a silicone resin composition of the present embodiment is referred to as a “silicone resin composition”.
A cured product obtained by curing the silicone resin composition is referred to as a “silicone resin cured product”.

(Silicone resin A)
In the silicone resin A, the structural unit contained is substantially only T-form, the proportion of T3-form in the T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight (Mw) is 1500 or more and 8000 or less. It is a silicone resin. Silicone resin A is commercially available, for example, as a silicone resin that is solid at room temperature.

  In the method for producing the silicone resin composition of the present embodiment, it is preferable to use a silicone resin that is solid at room temperature as the silicone resin A. By using a silicone resin that is solid at room temperature as the silicone resin A, the cured silicone resin is less likely to leave stickiness on the surface.

Here, in this specification, “T-form” means a structural unit containing a silicon atom bonded to three oxygen atoms.
Further, in this specification, “T3 body” means a structural unit in which all three oxygen atoms of the T body in the T body are bonded to other silicon atoms.

  “The structural unit to be contained is substantially only T-form” means that 95 mol% or more of the structural units of the silicone resin A is T-form. In the silicone resin A, 97 mol% or more of the structural units is preferably T-form, more preferably 99 mol% or more is T-form, and the structural unit other than T-form is below the detection limit. preferable.

  In this specification, the value measured by the gel permeation chromatography (GPC) method is used for the weight average molecular weight.

  Specifically, after dissolving the silicone resin in a soluble solvent and removing insolubles from the obtained solution by filter filtration, the obtained filtrate is used with a filler having many pores. Through the column along with the mobile phase solvent.

  In the measurement of the weight average molecular weight by the GPC method, the solvent used for dissolving the silicone resin is preferably the same solvent as the mobile phase solvent used for the GPC measurement. Specific examples of the solvent include tetrahydrofuran, chloroform, toluene, xylene, dichloromethane, dichloroethane, methanol, ethanol, isopropyl alcohol, and the like.

  The column used for GPC measurement is commercially available, and an appropriate column may be used according to the assumed weight average molecular weight.

  In the column, the silicone resin is separated according to the molecular weight. The silicone resin thus separated is detected for each molecular weight by using a differential refractometer, UV meter, viscometer, light scattering detector or the like as a detector.

  GPC dedicated devices are widely available commercially. Moreover, it is common to measure a weight average molecular weight by standard polystyrene conversion. The weight average molecular weight in this specification means what was measured by standard polystyrene conversion using a commercial measuring device.

  More specifically, the silicone resin A is composed of at least one silicon atom selected from the group consisting of a T1 silicon atom and a T2 silicon atom, and a T3 silicon atom. A silicone resin in which the ratio of the content of T3 silicon atoms to the total content of T2 silicon atoms and T3 silicon atoms is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .

Here, the T1 silicon atom is one oxygen atom in the structural unit represented by the following formula (A1) (the oxygen atom is bonded to a silicon atom in another bond unit), one In the structural unit represented by the following formula (A1 ′) or a silicon atom bonded to R ¹ and two R ^{2 s} , one bond (the bond is in other structural units) A silicon atom bonded to one R ¹ and two R ² ) (bonded to an oxygen atom bonded to a silicon atom).

The T2 silicon atom means one oxygen atom (the oxygen atom is bonded to a silicon atom in another structural unit) and one bond in the structural unit represented by the following formula (A2). (The bond is bonded to an oxygen atom bonded to a silicon atom in another structural unit) and is a silicon atom bonded to one R ¹ and one R ² .

The T3 silicon atom is a structural unit represented by the following formula (A3): two oxygen atoms (the oxygen atom is bonded to a silicon atom in another structural unit), one bond (The bond is bonded to an oxygen atom bonded to a silicon atom in another structural unit) and a silicon atom bonded to ^one R ¹ .
The structural unit represented by the above formula (A3) corresponds to “T3 body” in the present invention.

(Here, in formulas (A1), (A1 ′), (A2) and (A3), R ¹ represents an alkyl group having 1 to 3 carbon atoms, R ² represents an alkoxy group having 1 or 2 carbon atoms or a hydroxyl group) Represents.)

  “Substantially composed of at least one silicon atom selected from the group consisting of T1 silicon atom and T2 silicon atom and T3 silicon atom” means that 80 mol% or more of silicon atoms contained in silicone resin A Means any one of a T1 silicon atom, a T2 silicon atom, and a T3 silicon atom. The silicon atom contained in the silicone resin A is preferably 90 mol% or more of any of T1 silicon atom, T2 silicon atom and T3 silicon atom, and 95 mol% or more of T1 silicon atom, T2 silicon atom and T3 silicon. More preferably, it is any atom.

^{R 1} in the structural unit represented by the formula (A1), ^{R 1} in the structural unit represented by the formula (A1 '), ^{R 1} in the structural unit represented by the formula (A2), and, in the formula (A3) R ¹ in the structural unit represented may be the same or different.

^{R 2} of structural unit represented by the formula (A1), ^{R 2} in the structural unit represented by the formula (A1 '), and, ^{R 2} in the structural unit represented by the formula (A2) is a respectively identical Or different.

Two R ² in the structural unit represented by the formula (A1) may be the same or different. Two R ² in the structural unit represented by the formula (A1 ′) may be the same or different.

  The structural unit represented by the formula (A1) and the structural unit represented by the formula (A1 ′) constitute the end of the organopolysiloxane chain. Further, the structural unit represented by the formula (A3) constitutes a branched chain structure composed of an organopolysiloxane chain. That is, the structural unit represented by the formula (A3) forms part of a network structure or a ring structure in the silicone resin.

  In the silicone resin used in the present specification, the type and abundance ratio of the functional group bonded to the silicon atom can be measured by, for example, nuclear magnetic resonance spectroscopy (NMR method). Nuclear magnetic resonance spectroscopy (NMR method) is described in detail in various literatures, and dedicated measuring devices are also widely available on the market.

  Specifically, after dissolving the silicone resin to be measured in a specific solvent, a strong magnetic field and high-frequency radio waves are applied to the hydrogen nucleus or silicon nucleus in the silicone resin to resonate the nuclear magnetic moment in the nucleus. By this, the kind and abundance ratio of each functional group in the silicone resin can be measured.

A method for measuring hydrogen nuclei is called ¹ H-NMR. A method for measuring silicon nuclei is referred to as ²⁹ Si-NMR. As a solvent used for measurement of nuclear magnetic resonance spectroscopy (NMR method), deuterated chloroform, deuterated dimethyl sulfoxide, deuterated methanol, deuterated acetone, deuterated water, etc. may be selected depending on the types of various functional groups in the silicone resin.

The ratio of the content of T3 silicon atoms is the signal area attributed as T1 silicon atom, the signal area attributed as T2 silicon atom, and the signal attributed as T3 silicon atom, as determined in ²⁹ Si-NMR measurement. By dividing the area of the signal attributed as the T3 silicon atom by the total area with the above area, it can be obtained.

  In the silicone resin A, the ratio of the content of T3 silicon atoms to the total content of T1 silicon atoms, T2 silicon atoms, and T3 silicon atoms is preferably 70 mol% or more and 85 mol% or less.

In the structural unit contained in the silicone resin A, R ¹ is an alkyl group having 1 to 3 carbon atoms, and is preferably a methyl group. R ² is an alkoxy group having 1 or 2 carbon atoms or a hydroxyl group. When R ² is an alkoxy group, the alkoxy group is preferably a methoxy group or an ethoxy group.

The silicone resin A preferably has an organopolysiloxane structure represented by the following formula (1). In formula (1), R ¹ and R ² represent the same meaning as described above. p ¹ , q ¹ , a ¹ and b ¹ represent an arbitrary positive number.

The abundance ratio of each structural unit in the organopolysiloxane structure represented by the formula (1) is the number of T2 silicon atoms: x ¹ (= p ¹ + b ¹ × q ¹ ) and the number of T3 silicon atoms: y ¹ The T3 silicon atom content ratio (= y ¹ / (x ¹ + y ¹ )) with respect to the total content of (= a ¹ × q ¹ ) is within the range of 0.6 or more and 0.9 or less. It is preferable that it is in the range of 7 or more and 0.85 or less, and the numerical values of p ¹ , q ¹ , a ¹ , and b ¹ can be appropriately adjusted so as to be in such a range.

  Since the silicone resin A has a high abundance ratio of T3 silicon atoms, by curing the silicone resin A, a cured product in which the organopolysiloxane chain is configured in a network shape is obtained. If the abundance ratio of T3 silicon atoms is 0.9 or less, the thermal shock resistance of the cured silicone resin tends to be sufficiently high. Moreover, when the abundance ratio of T3 silicon atoms is 0.6 or more, the UV resistance of the cured silicone resin tends to be sufficiently high.

  The number of T2 silicon atoms and T3 silicon atoms per molecule of the silicone resin A can be adjusted by controlling the molecular weight of the resin having an organopolysiloxane structure represented by the above formula (1). In the present embodiment, the sum of the number of T2 silicon atoms and the number of T3 silicon atoms per molecule of the silicone resin A is preferably 5 or more.

  The weight average molecular weight of the silicone resin A is 1500 or more and 8000 or less. When the weight average molecular weight of the silicone resin A is too small, the UV resistance of the cured silicone resin tends to be low. When the weight average molecular weight of the silicone resin A is within the above range, a cured silicone resin having more excellent UV resistance can be obtained. The weight average molecular weight of the silicone resin A is preferably 1800 or more and 6000 or less, more preferably 2000 or more and 5000 or less, further preferably 2100 or more and 4500 or less, and particularly preferably 2500 or more and 4000 or less.

  The silicone resin A can be synthesized using an organosilicon compound having a functional group capable of forming a siloxane bond, corresponding to each of the above-described structural units constituting the silicone resin A.

  Here, examples of the “functional group capable of generating a siloxane bond” include a halogen atom, a hydroxyl group, and an alkoxy group. Examples of the organosilicon compound corresponding to the structural unit represented by the formula (A3) include organotrihalosilanes and organotrialkoxylanes. The silicone resin A can be synthesized by reacting such an organic silicon compound, which is a starting material, with a hydrolysis condensation method at a ratio corresponding to the abundance ratio of each structural unit. The silicone resin synthesized in this way is commercially available as a silicone resin or the like.

  In the method for producing a silicone resin of this embodiment, only one type of silicone resin A may be used, or two or more types may be used in combination.

(Silicone resin B)
Silicone resin B is a silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more. is there. Silicone resin B is commercially available, for example, as a silicone oligomer that is liquid at room temperature.

  In the method for producing the silicone resin composition of the present embodiment, it is preferable to use a silicone oligomer that is liquid at room temperature as the silicone resin B. By using a silicone oligomer that is liquid at normal temperature as the silicone resin B, the cured silicone resin has high impact resistance. In addition, the cured silicone resin easily adheres to the substrate or the semiconductor light emitting element.

  “The structural unit to be contained is substantially only T-form” means that 95 mol% or more of the structural units of the silicone resin B is T-form. In the silicone resin B, 97 mol% or more of the structural units is preferably T-form, more preferably 99 mol% or more is T-form, and the structural unit other than T-form is below the detection limit. preferable.

  More specifically, the silicone resin B is substantially composed of at least one silicon atom selected from the group consisting of a T1 silicon atom and a T2 silicon atom, and a T3 silicon atom. It is a silicone resin in which the ratio of the content of T3 silicon atoms to the total content of T2 silicon atoms and T3 silicon atoms is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.

  The T1 silicon atom, T2 silicon atom, and T3 silicon atom in the silicone resin B are the same as those described for the silicone resin A.

  “Substantially consisting of at least one silicon atom selected from the group consisting of T1 silicon atom and T2 silicon atom and T3 silicon atom” means that 80 mol% or more of silicon atoms contained in silicone resin B Means any one of a T1 silicon atom, a T2 silicon atom, and a T3 silicon atom. The silicon atom contained in the silicone resin B is preferably 90 mol% or more of any of T1 silicon atom, T2 silicon atom and T3 silicon atom, and 95 mol% or more of T1 silicon atom, T2 silicon atom and T3 silicon. More preferably, it is any atom.

  The ratio of the content of T3 silicon atom to the total content of T1 silicon atom, T2 silicon atom and T3 silicon atom is preferably 35 mol% or more and 55 mol% or less, and 40 mol% or more and 50 mol% or less. More preferably.

The silicone resin B preferably has an organopolysiloxane structure represented by the following formula (2). In formula (2), R ¹ and R ² represent the same meaning as described above. ^{p 2, q 2, r 2} , a 2 and ^{b 2} represent arbitrary positive number.

In the organopolysiloxane structure represented by the formula (2), the content ratio of T3 silicon atoms to the total content of T1 silicon atoms, T2 silicon atoms, and T3 silicon atoms (= [a ² × q ² ] / [(p ² + b ² × q ² ) + a ² × q ² + (r ² + q ² )]) is in the range of 0.3 to less than 0.6 and in the range of 0.35 to 0.55. It is preferable that it is within the range of 0.4 or more and 0.5 or less.

  The weight average molecular weight of the silicone resin B is 1500 or more. When the weight average molecular weight of the silicone resin B is within the above range, the thermal shock resistance of the cured silicone resin tends to be improved. The weight average molecular weight of the silicone resin B is preferably 1500 or more and 20000 or less, more preferably 1500 or more and 10,000 or less, and still more preferably 1500 or more and 6000 or less. The lower limit value of the weight average molecular weight of the silicone resin B is more preferably 2000 or more, and further preferably 3000 or more.

  The number of T1 silicon atoms, T2 silicon atoms and T3 silicon atoms in one molecule of silicone resin B is adjusted by controlling the molecular weight of the resin having an organopolysiloxane structure represented by the above formula (2). Can do. In the present embodiment, the sum of the number of T1 silicon atoms, the number of T2 silicon atoms and the number of T3 silicon atoms in one molecule of silicone resin B is preferably 5 or more.

  By curing the blend of silicone resin A and silicone resin B, the thermal shock resistance and adhesion between the cured product and the substrate or semiconductor light emitting element are further improved without damaging the high UV resistance of silicone resin A. A cured silicone resin can be obtained.

  The silicone resin B can be synthesized using an organosilicon compound having a functional group capable of forming a siloxane bond, corresponding to each of the structural units described above that constitute the silicone resin B. Here, the “functional group capable of generating a siloxane bond” has the same meaning as described above. Examples of the organosilicon compound corresponding to the structural unit represented by the formula (A3) include organotrihalosilanes and organotrialkoxylanes. Silicone resin B can be synthesized by reacting such an organic silicon compound, which is a starting material, with a hydrolysis condensation method at a ratio corresponding to the abundance ratio of each structural unit. The silicone resin synthesized in this way is commercially available as a silicone oligomer or the like.

  In the method for producing a silicone resin of the present embodiment, only one type of silicone resin B may be used, or two or more types may be used in combination.

(Silicone resin C)
Silicone resin C is a silicone resin having a mass reduction rate of less than 5% when heated from room temperature to 200 ° C. at a temperature rising rate of 5 ° C./min and held in air at 200 ° C. for 5 hours. Here, the temperature raising step from room temperature to 200 ° C. at a temperature raising rate of 5 ° C./min is usually performed in air. Such a silicone resin C is used as a filler.

  It can be said that the silicone resin C has few unreacted functional groups and is thermally stable. Furthermore, the silicone resin C is not easily altered even when irradiated with UV light having higher energy than visible light. Therefore, by blending the silicone resin C, the UV resistance of the cured silicone resin can be further improved.

  The silicone resin C is not particularly limited as long as it is thermally stable, and specifically, a silicone resin having a fine particle structure called silicone rubber powder or silicone resin powder can be used.

Among silicone resins having a fine particle structure, a silicone resin powder made of a polysilsesquioxane resin having a three-dimensional network structure in which a siloxane bond is represented by (RSiO _3/2 ) is preferable. In (RSiO _3/2 ), R is preferably a methyl group.

  When the silicone resin C is a silicone resin powder, various shapes such as a needle shape, a plate shape, and a spherical shape can be adopted as the particle shape. Especially, as a shape of the particle | grains of the silicone resin C, it is preferable that it is a spherical shape without anisotropy in a shape.

  The silicone resin C having a spherical particle shape is preferable because of high dispersibility in the silicone resin composition. In addition, the silicone resin C having a spherical particle shape has less irregularities on the particle surface, and it is difficult to form an air layer at the interface with the silicone resin A and the interface with the silicone resin B in the silicone resin composition. Is preferable because it is difficult to become cloudy.

  When the silicone resin C is a spherical silicone resin powder, the average particle size of the silicone resin powder is preferably 0.1 to 50 μm, more preferably 1 to 30 μm, and 2 to 20 μm. Is more preferable.

  If the average particle size of the silicone resin powder is within the above range (0.1 to 50 μm), the occurrence of peeling at the interface between the cured silicone resin and the substrate, the cloudiness of the cured silicone resin, the light of the cured silicone resin It tends to suppress the decrease in permeability.

  The average particle size of the silicone resin powder can be measured by, for example, a particle size distribution measuring apparatus using the “laser diffraction / scattering method” as a measurement principle. This method measures the particle size distribution of particles by utilizing the fact that when a particle is irradiated with a laser beam (monochromatic light), diffracted light and scattered light are emitted in various directions according to the size of the particle. It is a technique, and the average particle diameter can be obtained from the distribution state of diffracted light and scattered light. Devices using the “laser diffraction / scattering method” as a measurement principle are commercially available from many manufacturers.

  In the method for producing a silicone resin of this embodiment, only one type of silicone resin C may be used, or two or more types may be used in combination.

[Method 1 for producing silicone resin composition]
The production method 1 of the silicone resin composition of the present embodiment is a production method of a silicone resin composition using a silicone resin A and the following silicone resin B as raw materials, and a mixture of the silicone resin A and the silicone resin B is used. And a step of stirring until the following formula (A) is satisfied.
1.03 <Mw _com / Mw _ab <1.2 (A)
(Mw _ab is the weight average molecular weight of the mixture of the silicone resin A and the silicone resin B, and Mw _com is the weight average molecular weight of the product obtained by the stirring step.)

The “mixture of silicone resin A and silicone resin B” is composed only of silicone resin A and silicone resin B.
The “product obtained by the stirring step” is a reaction product resulting from the condensation reaction between the functional groups of the silicone resin A and the silicone resin B.

  The product (silicone resin composition) after stirring is a liquid having a viscosity of 100000 cP or less at normal temperature and normal pressure (25 ° C., 1 atm). 1 cP is 1 mPa · s.

  Silicone resin A and silicone resin B have an alkoxy group or a hydroxyl group bonded to a silicon atom as described above. In the mixture of the silicone resin A and the silicone resin B, a crosslinking point is formed by the condensation reaction between the silicone resin A and the silicone resin B, and the mixture becomes high molecular weight and cured. At that time, the silicone resin A and the silicone resin B are cured while producing desorption products such as alcohol and water in accordance with the condensation reaction.

  Thus, the elimination | release product produced | generated from the mixture of silicone resin A and silicone resin B may vaporize on the temperature conditions of a condensation reaction, and may produce a bubble in the hardened | cured material obtained by a condensation reaction.

  In addition to the above-described desorption products, the following may be considered as the cause of bubbles.

  First, the cause of the bubbles may be an organic solvent used in the production process of the silicone resin composition. When the organic solvent remains in the silicone resin composition, when the mixture of the silicone resin A and the silicone resin B undergoes a condensation reaction to become a cured product, it is vaporized under the temperature conditions of the condensation reaction, and bubbles are generated in the cured product. Sometimes.

Moreover, the low molecular weight silicone compound contained in the silicone resin A and the silicone resin B is also considered as a cause of bubbles. Examples of the “low molecular weight silicone compound” include cyclic siloxane which is a raw material of the silicone resin A and the silicone resin B and remains in the silicone resin A and the silicone resin B. The cyclic siloxane is, for example, a trimer to a 10-mer of — (CH ₃ ) ₂ Si—O— units.

  Examples of the “low molecular weight silicone compound” include chain siloxanes that are contained in the silicone resin A and the silicone resin B and have a molecular weight similar to that of the above-described cyclic siloxane.

  In addition, air mixed during mixing of raw materials in the production process of the silicone resin composition can also cause bubbles.

  Bubbles generated in the silicone resin composition emerge at the interface between the silicone resin composition and the ambient atmosphere gas. When bubbles break at the interface of the silicone resin composition, the surface of the resulting cured product may be roughened. That is, the bubbles generated in the silicone resin composition cause unevenness on the surface of the cured product to be generated.

  Further, when the condensation reaction is completed while the bubbles generated in the silicone resin composition remain in the silicone resin composition, the obtained cured product has bubbles inside.

  Such irregularities on the surface of the cured product and bubbles inside the cured product can be a scattering source that scatters light. Therefore, if the LED is sealed using such a cured product having surface irregularities and internal bubbles, the light emitted from the LED may be scattered, and the performance of the light source device using the LED as a light source may be deteriorated. is there.

On the other hand, in the manufacturing method of the silicone resin composition of this embodiment, the mixture of silicone resin A and silicone resin B is stirred under reduced pressure until 1.03 < _Mwcom / _Mwab is satisfied.

By the above stirring, the mixture of the silicone resin A and the silicone resin B proceeds to a high molecular weight until the condensation reaction proceeds until 1.03 <Mw _com / Mw _ab is satisfied. Therefore, in the mixture of silicone resin A and silicone resin B, a desorption product corresponding to the amount of the condensation reaction has been released.

  Moreover, in the manufacturing method of the silicone resin composition of this embodiment, the said stirring is performed under reduced pressure. Therefore, the elimination product generated by the condensation reaction is easily removed out of the reaction system.

Therefore, when the mixture of silicone resin A and silicone resin B is stirred under reduced pressure until 1.03 <Mw _com / Mw _ab is satisfied, the mixture of silicone resin A and silicone resin B is preliminarily polymerized. A resin composition is obtained.

  In the resulting silicone resin composition, the desorption products generated in the above-described high molecular weight are removed during the production process. Therefore, the amount of the desorption product generated when the obtained silicone resin composition is cured is smaller than the amount of the desorption product generated when the above-mentioned mixture before high molecular weight is cured. Therefore, the resulting silicone resin composition suppresses the generation of bubbles when cured.

In the method for producing the silicone resin composition of the present embodiment, the mixture of the silicone resin A and the silicone resin B is preferably stirred under reduced pressure until 1.035 <Mw _com / Mw _ab is satisfied, and 1.04 < It is more preferable to stir until _Mwcom / _Mwab is satisfied.

Moreover, in the manufacturing method of the silicone resin composition of this embodiment, the mixture of silicone resin A and silicone resin B is stirred under reduced pressure until _Mwcom / _Mwab <1.2 is satisfied.

As described above, the mixture of the silicone resin A and the silicone resin B is stirred to increase the molecular weight. On the other hand, if the mixture becomes too high in molecular weight as Mw _com / Mw _ab is 1.2 or more, the resulting product becomes highly viscous and difficult to handle. For example, when the silicone resin composition produced by the production method of the present embodiment is too high in viscosity, the fluidity is lowered, and it is difficult to seal the LED by dropping (potting) on the LED. In addition, if the condensation reaction between the silicone resin A and the silicone resin B proceeds excessively, the condensation reaction is more likely to proceed while the obtained silicone resin composition is being stored, and may solidify during storage.

On the other hand, by suppressing the condensation reaction of the mixture of the silicone resin A and the silicone resin B at Mw _com / Mw _ab <1.2, the fluidity of the resulting silicone resin composition is ensured and easy to handle. Become. For example, when the silicone resin composition has an appropriate viscosity, it can be dropped (potted) on the LED to seal the LED, and at the same time as the sealing, the surface of the sealing portion is made into a lens-like convex. It can be a curved surface.

In the method for producing the silicone resin composition of the present embodiment, the mixture of the silicone resin A and the silicone resin B is preferably stirred under reduced pressure until Mw _com / Mw _ab <1.15 is satisfied, and Mw _com / Mw it is more preferable to stir until satisfy _{ab <1.10,} it is more preferable to stir until it meets the Mw _com / Mw ab <1.09.

Therefore, when the mixture of the silicone resin A and the silicone resin B is stirred under a reduced pressure environment until 1.03 <Mw _com / Mw _ab <1.2, the mixture of the silicone resin A and the silicone resin B undergoes a condensation reaction. The resulting elimination product produced can be excluded.

  When the resulting product (silicone resin composition) is used as a sealing material and the LED is sealed, compared to the case where the mixture before stirring is used as the sealing material, after potting on the LED, until the sealing portion is formed The total amount of desorption products generated in the curing reaction is reduced. Furthermore, in the production process of the silicone resin composition, by causing heating and stirring and depressurization, the cause of bubbles other than the desorption product can be easily removed from the silicone resin composition. Therefore, the silicone resin composition produced by the production method of the silicone resin composition of the present embodiment suppresses the amount of substances that cause bubbles such as desorption products, and easily produces a high-quality cured silicone resin. It becomes possible.

In the step of stirring, it may be confirmed that the mixture of silicone resin A and silicone resin B satisfies 1.03 <Mw _com / Mw _ab <1.2 by appropriately measuring the polymerization average molecular weight by the GPC method. Further, when the method for producing the silicone resin composition of the present embodiment is repeatedly performed, it is preliminary that the mixture of the silicone resin A and the silicone resin B satisfies 1.03 < _Mwcom / _Mwab <1.2. It is good to confirm by experiment and to stir under the confirmed conditions.

_Mwcom is preferably 2500 or more and less than 24000, more preferably 2500 or more and 7200 or less, and further preferably 3500 or more and 5500 or less.

Mw _ab is preferably 1500 or more and 15000 or less, more preferably 1500 or more and 6000 or less, further preferably 2100 or more and 6000 or less, and further preferably 3400 or more and 5000 or less.

When Mw _com and Mw _ab are in the above ranges, the thermal shock resistance of the cured silicone resin formed from the silicone resin composition tends to be improved. Moreover, it exists in the tendency for a silicone resin hardened | cured material to show the more outstanding UV tolerance.

  In the step of stirring, the composition containing the mixture may be stirred. In this case, the content of the organic solvent in the composition is preferably 1% by mass or less.

  When the composition with reduced organic solvent is stirred under reduced pressure, the resulting silicone resin composition is less likely to contain an organic solvent. Therefore, when the silicone resin composition is cured, bubbles due to the organic solvent contained in the silicone resin composition are hardly generated, and surface unevenness and internal bubbles are hardly generated in the cured silicone resin obtained from the silicone resin composition. Become. Furthermore, the organic solvent can be oxidized or decomposed by heating and cause coloring of the cured product. However, such coloring can be suppressed by making the content rate of an organic solvent into 1 mass% or less.

  In the manufacturing method of a silicone resin composition, the silicone resin A and the silicone resin B which are raw materials are mixed in arbitrary ratios. In the raw material, the mass ratio of the silicone resin A and the silicone resin B is preferably [silicone resin A]: [silicone resin B] = 10: 90 to 60:40.

  Here, [silicone resin A] indicates the mass of silicone resin A, and [silicone resin B] indicates the mass of silicone resin A. Moreover, the boundary value of the said range shall be contained in the range.

  In the silicone resin composition, the content of the silicone resin A with respect to the total amount of the silicone resin A and the silicone resin B is preferably 10% by mass or more. When the content rate of silicone resin A is the said value, the UV tolerance of a silicone resin hardened | cured material can be improved.

  When the phosphor resin or other filler-like powder is further added to and mixed with the silicone resin composition produced in this embodiment, the silicone resin composition preferably has appropriate fluidity. When the silicone resin A is solid at room temperature, in the silicone resin composition, the content of the silicone resin A with respect to the total amount of the silicone resin A and the silicone resin B is preferably 60% by mass or less. When the content rate of silicone resin A is the said value, in a silicone resin composition, mixing with various powder becomes easy.

  Since the silicone resin composition can be easily handled and high UV resistance can be imparted to the cured silicone resin, the content of the silicone resin A relative to the total amount of the silicone resin A and the silicone resin B is 30% by mass or more and 50% by mass. % Or less ([silicone resin A]: [silicone resin B] = 30: 70 to 50:50) is more preferable.

  The manufacturing method of the silicone resin composition of this embodiment may stir the composition which added the silicone resin C further to the mixture of the silicone resin A and the silicone resin B as needed in the process to stir.

Silicone resin C is usually insoluble in the solvent. In the measurement of the weight average molecular weight by the GPC method, when the silicone resin C is included in the measurement sample, the silicone resin C is removed by filter filtration when preparing a solution for GPC measurement. Therefore, even when the silicone resin composition is produced using the silicone resin C, the mixture of the silicone resin A and the silicone resin B is stirred until 1.03 <Mw _com / Mw _ab <1.2. can do.

  The content (resin content) of the silicone resin C with respect to the total amount of the silicone resin A, the silicone resin B, and the silicone resin C is preferably 20 to 60% by mass, and 30 to 50% by mass. More preferably. When the silicone resin composition in which the resin content of the silicone resin C is within the above range is cured, a cured product having a good balance between thermal shock resistance and UV resistance tends to be obtained.

[Method 2 for producing silicone resin composition]
In the stirring step described above, the mixture of the silicone resin A and the silicone resin B may be stirred from the beginning of stirring, or the silicone resin A and the silicone resin B may be stirred separately. Specifically, in the step of stirring described above, the first step of stirring the silicone resin B, and the silicone resin A added to the high molecular weight silicone resin B obtained in the first step are mixed to form a mixture. It is good also as what has a 2nd process which stirs.

That is, the manufacturing method 2 of the silicone resin composition of the present embodiment is a manufacturing method of a silicone resin composition using the silicone resin A and the following silicone resin B as raw materials, and the silicone resin B is in a reduced pressure environment of 200 hPa or less. The first step of obtaining a silicone resin B1 having a high molecular weight of the silicone resin B by stirring while heating to 100 ° C. or higher, and adding the silicone resin A to the silicone resin B1 to obtain a mixture, the mixture is reduced to 200 hPa or less. And a second step of stirring while heating to 100 ° C. or higher in a reduced pressure environment. In the second step, the mixture is stirred until the following formula (A) is satisfied.
1.03 <Mw _com / Mw _ab <1.2 (A)
(Mw _ab is the weight average molecular weight of the mixture of the silicone resin A and the silicone resin B, and Mw _com is the weight average molecular weight of the product obtained in the second step.)

“Silicone resin B1” is a polymer obtained by condensing silicone resin B in the first step to increase the molecular weight.
The “product obtained by the second step” is a reaction product resulting from the condensation reaction between the functional groups of the silicone resin A and the silicone resin B1.

(First step)
In the first step, the silicone resin B may be stirred while being heated to 100 ° C. or higher in a reduced pressure environment of 200 hPa or less.

  The pressure condition in the first step is preferably 200 hPa or less, more preferably 100 hPa or less, further preferably 50 hPa or less, and particularly preferably 20 hPa or less.

  The heating temperature in the first step is preferably 100 ° C. or higher, and more preferably 120 ° C. or higher. Further, the heating temperature in the first step is preferably 180 ° C. or lower, and more preferably 170 ° C. or lower. The upper limit value and the lower limit value can be arbitrarily combined.

By setting the heating temperature in the first step within the above range, Mw _com / Mw _ab can be easily managed to be less than 1.2, and the product obtained in the first step is difficult to increase in viscosity. Therefore, handling of the product obtained in the first step becomes easy.

  The stirring time after reaching the heating temperature in the first step is preferably 15 minutes or more, and more preferably 30 minutes or more. Further, the stirring time after reaching the heating temperature in the first step is preferably 10 hours or less, and more preferably 8 hours or less. The upper limit value and the lower limit value can be arbitrarily combined.

By setting the stirring time in the first step within the above range, Mw _com / Mw _ab can be easily managed to be less than 1.2, and the product obtained in the first step is difficult to increase in viscosity. Therefore, handling of the product obtained in the first step becomes easy.

  About each condition of the pressure of the 1st process mentioned above, heating temperature, and stirring time, if the content rate of the organic solvent contained in silicone resin B1 obtained at the 1st process is 1 mass% or less, it can combine arbitrarily. it can.

In this embodiment, the value measured by the gas chromatography method (GC method) is employ | adopted for the content rate of the organic solvent in silicone resin B1 obtained at a 1st process.
In the measurement of the organic solvent content by the GC method, the solvent used may be a solvent in which a silicone resin is soluble, such as tetrahydrofuran, acetone, methanol, ethanol, isopropyl alcohol, γ-butyrolactone, and hexane.

  As an example, the first step is performed by heating and stirring the silicone resin B at 140 ° C. and 10 hPa for 1 hour.

  By performing the first step, the condensation reaction of part of the silicone resin B proceeds to become the silicone resin B1. Further, the elimination product generated by the condensation reaction is removed from the silicone resin B1.

(Second step)
In the second step, the silicone resin A is added to the silicone resin B1 obtained in the first step to obtain a mixture. Thereafter, the obtained mixture may be stirred while being heated to 100 ° C. or higher under a reduced pressure environment of 200 hPa or less.

  The pressure condition in the second step is preferably 200 hPa or less, more preferably 100 hPa or less, further preferably 50 hPa or less, and particularly preferably 20 hPa or less.

  The heating temperature condition in the second step is preferably 100 ° C. or higher, and more preferably 120 ° C. or higher. Further, the heating temperature in the second step is preferably 180 ° C. or lower, and more preferably 170 ° C. or lower. The upper limit value and the lower limit value can be arbitrarily combined.

By setting the stirring time in the second step within the above range, Mw _com / Mw _ab can be easily managed to be less than 1.2, and the product obtained in the second step is difficult to increase in viscosity. Therefore, handling of the product obtained in the second step becomes easy.

  The stirring time after reaching the heating temperature in the second step is preferably 15 minutes or more, and more preferably 30 minutes or more. Further, the stirring time after reaching the heating temperature in the second step is preferably 10 hours or less, and more preferably 8 hours or less. The upper limit value and the lower limit value can be arbitrarily combined.

By setting the stirring time in the second step within the above range, Mw _com / Mw _ab can be easily managed to be less than 1.2, and the product obtained in the second step is difficult to increase in viscosity. Therefore, handling of the product obtained in the second step becomes easy.

The above-mentioned conditions of the pressure, heating temperature, and stirring time in the second step are arbitrarily combined as long as the obtained silicone resin composition satisfies the condition 1.03 < _Mwcom / _Mwab <1.2. be able to.

  As an example, the second step is performed by heating and stirring the silicone resin B at 140 ° C. and 10 hPa for 1 hour.

  Each condition of the first step and each condition of the second step may be the same or different.

  By performing the second step, the silicone resin A and the silicone resin B1 are dissolved together, and the condensation reaction of the mixture of the silicone resin A and the silicone resin B1 proceeds. Further, the desorption product is removed from the mixture of the silicone resin A and the silicone resin B1.

By such a production method, the mixture of the silicone resin A and the silicone resin B1 may be stirred under reduced pressure until 1.03 <Mw _com / Mw _ab <1.2.

In addition, when manufacturing a silicone resin composition using the silicone resin C in addition to the silicone resin A and the silicone resin B, the silicone resin B and the silicone resin C are mixed in the first step under a reduced pressure environment of 200 hPa or less. It is good to obtain the silicone resin D containing the silicone resin B1 by stirring while heating to 100 ° C. or higher.
Hereinafter, “silicone resin D including silicone resin B1” is simply referred to as “silicone resin D”.

  In the first step, when the silicone resin D is prepared by mixing the silicone resin B and the silicone resin C, the powdered silicone resin C entrains air so that bubbles are included in the silicone resin D. May be.

  Therefore, when the silicone resin B and the silicone resin C are mixed in the first step, the conditions of the pressure, the heating temperature, and the stirring time in the first step described above are the bubbles in addition to the organic solvent content described above. Can be arbitrarily combined under the condition that the surface does not appear on the surface of the silicone resin D.

  The silicone resin composition produced by the method for producing a silicone resin composition in this way has a small residual amount of air that can be mixed in during the production process, and the generation amount of desorption products that cause surface irregularities and bubbles. Can be suppressed. Therefore, a high-quality cured product can be easily manufactured.

(Other additives)
In the method for producing the silicone resin composition of the present embodiment, a silane coupling agent, a reaction promoting catalyst, and other additives may be further added to the mixture of the silicone resin A and the silicone resin B.

(Silane coupling agent)
The silane coupling agent has an effect of improving the adhesion between a cured product obtained by curing the silicone resin composition and the semiconductor light emitting device or the substrate. The silane coupling agent has at least one group selected from the group consisting of vinyl group, epoxy group, styryl group, methacryl group, acrylic group, amino group, ureido group, mercapto group, sulfide group and isocyanate group. A silane coupling agent is preferable, and a silane coupling agent having an epoxy group or a mercapto group is more preferable.

  Specific examples of the silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycol. Sidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned.

When the silane coupling agent is contained in the silicone resin composition produced by the production method of the present embodiment, silicon atoms contained in the silane coupling agent are also detected as ²⁹ Si-NMR signals. Therefore, in the present specification, when calculating the signal area of the silicone resin composition (signal area attributed as T1 silicon atom, signal area attributed as T2 silicon atom and signal area attributed as T3 silicon atom) Coupling agent signals should also be included.

  The content of the silane coupling agent used in the method for producing the silicone resin composition of the present embodiment is 100 parts by mass of the total content of the silicone resin A and the silicone resin B, or the silicone resin A, the silicone resin B, and the silicone resin C. Preferably it is 0.0001-1.0 mass part with respect to 100 mass parts (resin content) of total content, More preferably, it is 0.001-0.1 mass part. If the content of the silane coupling agent is higher than the above range, the silane coupling agent itself may absorb light, thereby reducing the transparency of the cured product obtained by curing the silicone resin composition.

(Catalyst for reaction promotion)
In general, a reaction promoting catalyst such as an acidic compound, an alkaline compound, or a metal compound may be added to the silicone resin composition. In the method for producing the silicone resin composition of the present embodiment, a reaction promoting catalyst may be added to the mixture of the silicone resin A and the silicone resin B in the stirring step.

By adding the reaction promoting catalyst, in the stirring step, the time until the mixture of the silicone resin A and the silicone resin B satisfies 1.03 < _Mwcom / _Mwab <1.2 is shortened. Alternatively, by adding a reaction promoting catalyst, the heating temperature in the step of heating and stirring can be lowered as compared with the case where the reaction promoting catalyst is not used.

  In the case of using the reaction promoting catalyst, various catalysts can be used as the reaction promoting catalyst as long as they can promote the condensation reaction of the silicone resin composition.

  When the functional groups of the silicone resin A and the silicone resin B are an alkoxy group or a hydroxyl group, an inorganic acid or an organic acid can be used as a reaction promoting catalyst in order to promote a hydrolysis condensation reaction. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. Examples of the organic acid include formic acid, acetic acid, succinic acid, citric acid, propionic acid, butyric acid, lactic acid, and succinic acid.

  In addition, an alkaline compound can be used as the reaction promoting catalyst. Examples of the alkaline compound include ammonium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

  In addition, the content of the reaction accelerating catalyst is 0. 0% relative to the total content of the silicone resin A and the silicone resin B or the total content (resin content) of the silicone resin A, the silicone resin B, and the silicone resin C. It is preferably 5% by mass or less, and more preferably 0.05% by mass or less.

  In the method for producing the silicone resin composition of the present embodiment, when a metal catalyst is used as the reaction promoting catalyst, the content of the metal catalyst is preferably 0.05% by mass or less, and 0.01% by mass. More preferably, it is more preferably 0.001% by mass or less.

(Other additives)
Examples of other additives include silicone resins, silicone oligomers, and silicone compounds that are different from silicone resin A, silicone resin B, and silicone resin C. Specific examples of other additives include general modifying silicone compounds that are commercially available. When the silicone resin composition of the present embodiment includes the modifying silicone compound, flexibility can be imparted to the cured silicone resin. Examples of the modifying silicone compound include polymers and oligomers having a dialkylsiloxane structure whose main chain is R ₂ SiO _2/2 (where R represents an alkyl group).

When a silicone compound is contained in the silicone resin composition produced by the production method of the present embodiment, silicon atoms contained in the silicone compound are also detected as ²⁹ Si-NMR signals. Therefore, in the present specification, silicone is calculated when calculating the signal area of the silicone resin composition (signal area attributed as T1 silicon atom, signal area attributed as T2 silicon atom and signal area attributed as T3 silicon atom). Compound signals should also be included.

  In the manufacturing method of the silicone resin composition of the present embodiment, the amount of the silicone compound used is 100 parts by mass of the total content of the silicone resin A and the silicone resin B, or the total of the silicone resin A, the silicone resin B, and the silicone resin C. Preferably it is 0.1-20 mass parts with respect to 100 mass parts (resin content) of content, More preferably, it is 0.5-10 mass parts. When content of a silicone compound is higher than the said range, transparency of the hardened | cured material obtained by hardening a silicone resin composition may be impaired.

  Other examples of the additive include, for example, an antifoaming agent for suppressing bubbles generated when the silicone resin composition is mixed.

(Silicone resin composition)
The following silicone resin composition can be produced by the method for producing a silicone resin composition as described above.

  The silicone resin composition of this embodiment is a silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials. The horizontal axis is obtained by GPC measurement, the horizontal axis is the molecular weight in terms of standard polystyrene, and the vertical axis The evaluation value obtained by the following method is less than 25 based on the molecular weight distribution curve in which is the detection intensity of the differential refractive index detector.

Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms.
The T3 body means a structural unit in which all three oxygen atoms of the T body in the T body are bonded to other silicon atoms. )

(Evaluation value calculation method)
In the molecular weight distribution curve, the peak value of the vertical axis of the molecular weight distribution curve is such that the peak top intensity is −1 for the peak having the maximum absolute value among the peaks having a molecular weight of 245 to 400 and less than 0 intensity. To standardize.
Surrounded by the normalized molecular weight distribution curve and a straight line (reference line) represented by a linear expression connecting two points of a molecular weight of 140 and a point of 245 in the normalized molecular weight distribution curve The sum of the normalized detection intensity values in the determined area is obtained as an evaluation value.
(The normalized detection intensity value in the region surrounded by the reference line and the normalized molecular weight distribution curve is the above-mentioned reference line for each molecular weight arranged at a molecular weight interval corresponding to a data acquisition time interval of 0.3 seconds for GPC measurement. It means the value obtained by subtracting the normalized detection intensity value.)

  The evaluation value calculated | required by the said method is a value used as the parameter | index for evaluating content of the low molecular weight component contained in a silicone resin composition. It can be evaluated that the smaller the evaluation value, the less the low molecular weight component contained in the silicone resin composition.

  In obtaining the evaluation value in the present invention, the silicone resin composition is subjected to GPC measurement under the following conditions, and the obtained molecular weight distribution curve is used. The molecular weight distribution curve is determined using a chromatogram obtained by GPC measurement and a calibration curve indicating the relationship between the molecular weight of standard polystyrene with respect to GPC elution time determined in advance using standard polystyrene.

<GPC measurement conditions>
Apparatus: Tosoh HLC-8220
Column: TSKgel Multipore HXL-M × 3 + Guardcolumn-MP (XL)
Flow rate: 1.0 mL / min Detection condition: RI (polarity +)
Concentration: 100 mg + 5 mL (THF)
Injection volume: 100 μL
Column temperature: 40 ° C
Eluent: THF (tetrahydrofuran)
Molecular weight standard: Standard polystyrene data acquisition time interval: 0.3 seconds

  In the molecular weight distribution curve obtained for the silicone resin composition, it is considered that low molecular weight components contained in the silicone resins A and B are detected in the molecular weight range of 140 to 400. Such a low molecular weight component is considered to be a low molecular weight silicone contained in the silicone resins A and B. In the technical field of silicone resin compositions, the content of such low-molecular-weight components derived from raw materials is very small, but in this embodiment, low-molecular-weight components contained in small amounts can cause the above-mentioned bubbles. Therefore, the inventors paid attention to the amount of the low molecular weight component.

  According to the inventors' investigation, in the silicone resin composition produced by the above-described method for producing the silicone resin composition of the present embodiment, components having a molecular weight in the range of 140 to 245 among low molecular weight components are reduced. I understood. This is presumably because low molecular weight components having a molecular weight in the range of 140 to 245 were volatilized and removed by heating and stirring or reducing pressure in the method for producing the silicone resin composition of the present embodiment. Since it tends to volatilize, a low molecular weight component having a molecular weight in the range of 140 to 245 is considered to cause the above-mentioned bubbles.

  On the other hand, in the silicone resin composition produced by the above-described method for producing the silicone resin composition of the present embodiment, the components having a molecular weight in the range of 245 to 400 among the low molecular weight components are silicone resins. It turned out that it does not reduce even if it performs heating stirring and pressure reduction in the manufacturing method of a composition.

  Therefore, in this embodiment, in order to evaluate the amount of the low molecular weight component in the molecular weight range of 140 to 245, which is reduced by the method for producing the silicone resin composition, the evaluation value obtained by the above method is defined. According to the study by the inventors, it was found that the silicone resin composition having an evaluation value of less than 25 is less likely to be mixed with bubbles in the obtained cured product, and a high-quality cured product can be obtained.

  The above evaluation value is preferably 20 or less, more preferably 15 or less, and further preferably 10 or less. The lower limit is not particularly limited, but is preferably 0.5 or more, more preferably 1.0 or more, still more preferably 1.5 or more, and particularly preferably 2.0 or more. When the lower limit value of the evaluation value is within the above range, the silicone resin composition appropriately contains a low molecular weight component, thereby improving the flexibility of the cured product obtained by curing the silicone resin composition, and thermal shock. High tolerance can be achieved.

  The silicone resin composition produced by the method for producing a silicone resin composition of the present embodiment includes silicone resin A and silicone resin B. Further, in the obtained silicone resin composition, the silicon atom contained in the resin composition is substantially composed of at least one silicon atom selected from the group consisting of T1 silicon atom and T2 silicon atom, and T3 silicon atom. , The ratio of the content of T3 silicon atom to the total content of T1 silicon atom, T2 silicon atom and T3 silicon atom is 50 mol% or more and 99 mol% or less, and the side chain bonded to the silicon atom is carbon It contains a C 1-3 alkyl group and a C 1 or C 2 alkoxy group, and the molar ratio of the alkoxy group is 5 or more with respect to the alkyl group 100.

  The T1 silicon atom, T2 silicon atom, and T3 silicon atom in the silicone resin composition are the same as those described for the silicone resin A.

  In the obtained silicone resin composition, the molar ratio of the hydroxyl group contained in the side chain bonded to the silicon atom is preferably 10 or more with respect to the alkyl group 100.

  The silicone resin composition produced by the production method of this embodiment is useful for producing a cured product exhibiting high thermal shock resistance. Since such a cured product has high UV transparency and high UV resistance (light resistance), it can be suitably used as a sealing material for UV-LED.

  In this specification, the thermal shock resistance of the cured silicone resin is high, for example, a temperature cycle of 100 ° C. for 30 minutes at −30 ° C. and then 30 minutes at 85 ° C. This means that cracks are hardly generated in the cured silicone resin even when repeated thermal shock is applied.

  In this specification, the high UV resistance of the cured silicone resin means that the cured silicone resin has little deterioration such as discoloration and occurrence of cracks even when the cured silicone resin is irradiated with UV light. . Here, the UV light means light having a wavelength of about 250 to 400 nm.

  Furthermore, in the silicone resin composition produced by the method for producing a silicone resin composition of the present embodiment, the amount of desorption products generated when cured is such that the mixture of silicone resin A and silicone resin B is cured. Less than the amount of desorption product produced. Therefore, surface unevenness is hardly generated in the obtained cured product, and bubbles are not easily mixed inside the cured product.

  Therefore, according to the method for producing a silicone resin composition having the above configuration, a high-quality cured product can be easily produced.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

<GPC measurement>
In this example, the GPC method was used for molecular weight measurement of the silicone resin and the silicone resin composition. During preparation of the solution for GPC measurement, insoluble matters in the solution were removed using a disposable filter unit (manufactured by Advantech Toyo Co., Ltd., DISMIC-25HP, pore size 0.45 μm). About the obtained preparation solution, the weight average molecular weight of standard polystyrene conversion was measured on condition of the following.
The measurement conditions were as follows.

<GPC measurement conditions>
Apparatus: Tosoh HLC-8220
Column: TSKgel Multipore HXL-M × 3 + Guardcolumn-MP (XL)
Flow rate: 1.0 mL / min Detection condition: RI (polarity +)
Concentration: 100 mg + 5 mL (THF)
Injection volume: 100 μL
Column temperature: 40 ° C
Eluent: THF (tetrahydrofuran)
Molecular weight standard: Standard polystyrene data acquisition time interval: 0.3 seconds

<Calculation of evaluation value of content of low molecular weight component>
Hereinafter, the evaluation value of the content of the low molecular weight component contained in the silicone resin compositions obtained in Examples and Comparative Examples was obtained by analyzing the molecular weight distribution curve obtained under the above GPC measurement conditions. The horizontal axis of the molecular weight distribution curve indicates the molecular weight in terms of standard polystyrene, and the vertical axis indicates the detection intensity of the differential refractive index detector.

  First, in the obtained molecular weight distribution curve, the vertical axis of the molecular weight distribution curve is such that the peak top intensity is −1 for the peak having the maximum absolute value among the peaks having a molecular weight of 245 to 400 and less than 0 intensity. Axis values were normalized.

  Next, it is surrounded by a normalized molecular weight distribution curve and a straight line (reference line) expressed by a linear expression connecting two points of a molecular weight of 140 and a point of 245 in the normalized molecular weight distribution curve. The sum of the normalized detection intensity values in each region was obtained. Here, the standardized detection intensity value in the region surrounded by the reference line and the standardized molecular weight distribution curve is the standard for each molecular weight arranged at a molecular weight interval corresponding to a data acquisition time interval of GPC measurement of 0.3 seconds. It means a value obtained by subtracting the normalized detection intensity value from a line. The sum of the obtained normalized detection intensity values was used as the evaluation value.

<Specification of silicon atom type in silicone resin and silicone resin composition and measurement of abundance ratio of substituents>
In this example, the solution ¹ H-NMR method or the solution ²⁹ Si-NMR method was used as a means for specifying the type of silicon atom in the raw material silicone resin and measuring the abundance ratio of substituents in the silicone resin. It was.

<Solution ¹ H-NMR measurement conditions>
Device name: ECA-500 manufactured by JEOL RESONANCE
Observation nucleus: 1H
Observation frequency: 500.16 MHz
Measurement temperature: room temperature measurement solvent: DMSO-d ₆
Pulse width: 6.60 μsec (45 °)
Pulse repetition time: 7.0 sec
Integration count: 16 times Sample concentration (sample / measuring solvent): 300 mg / 0.6 ml

<Solution ²⁹ Si-NMR measurement conditions>
Device name: 400-MR manufactured by Agilent
Observation nucleus: ²⁹ Si
Observation frequency: 79.42 MHz
Measurement temperature: room temperature measurement solvent: CDCl ₃
Pulse width: 8.40 μsec (45 °)
Pulse repetition time: 15.0 sec
Integration count: 4000 times Sample concentration (sample / measuring solvent): 300 mg / 0.6 ml

<GC measurement conditions>
In this specification, the value measured by the gas chromatography (GC) method was used for the organic solvent content of the silicone resin composition. The measurement conditions were as follows.

<GC measurement conditions>
Apparatus: Agilent 6890 type column: CP-PorabbondQ (0.25 mmφ × 30 m, 0.25 μm)
Carrier gas: helium split ratio: 40: 1
Column temperature: held at 50 ° C for 5 minutes, heated at 10 ° C / minute, held at 300 ° C for 10 minutes Inlet temperature: 200 ° C
Detector: FID
Detector temperature: 250 ° C
IS reagent: Diluting solvent for methyl isobutyl ketone: γ-butyrolactone

(Silicone resin)
As the silicone resin A, a silicone resin 1 having an organopolysiloxane structure represented by the above general formula (1) (R ¹ = methyl group, R ² = methoxy group or hydroxyl group in the above general formula (1)) was used. . Table 1 shows the abundance ratio of each structural unit of the silicone resin 1.

  When the weight average molecular weight of the silicone resin 1 was measured, it was Mw = 3100.

As the silicone resin B, a silicone resin 2 having an organopolysiloxane structure represented by the above general formula (2) (R ¹ = methyl group, R ² = methoxy group in the above general formula (2)) was used. The abundance ratio of each structural unit of the silicone resin 2 is shown in Table 2.

  When the weight average molecular weight of the silicone resin 2 was measured, it was Mw = 5600.

As silicone resin C, silicone resin 3 manufactured by Shin-Etsu Chemical Co., Ltd. (trade name “KMP-701”, R: RSiO _3/2 in the formula: RSiO _3/2 is a methyl group, and methoxy group and hydroxyl group are functional groups capable of forming a siloxane bond. Used.). When the silicone resin 3 was heated from room temperature to 200 ° C. at a rate of temperature increase of 5 ° C./min and held in air at 200 ° C. for 5 hours, the mass reduction rate was 0.6%.
The silicone resin 3 is a silicone resin powder having an average particle size of 3.5 μm (catalog value) and a particle size distribution of 1 to 6 μm (catalog value).

Example 1
15 g of silicone resin 2 and 25 g of silicone resin 3 are added to a glass container for a rotary evaporator and heated and stirred at 140 ° C. for 1 hour in a reduced pressure environment of 10 hPa to obtain white transparent viscous silicone resin 4. It was. This operation corresponds to the “first step” in the above embodiment.

  The content of the organic solvent in the resulting viscous silicone resin 4 was not more than the detection lower limit.

  10 g of the silicone resin 1 was added to the obtained silicone resin 4, and the mixture was further heated and stirred at 140 ° C. for 1 hour under a reduced pressure environment of 10 hPa to obtain the silicone resin composition 1 of Example 1. Silicone resin composition 1 was white and transparent. This operation corresponds to the “second step” in the above embodiment.

A mixture of 15 g of silicone resin 2 and 10 g of silicone resin 1 dissolved in THF was measured for weight average molecular weight (Mw _ab ) by the above-mentioned GPC measurement. Mw = 3900 (average value of n = 2) Met.
Moreover, when the weight average molecular weight ( _Mwcom ) of the silicone resin composition 1 was measured, it was Mw = 4200 (n = 2 average value).
That is, _Mwcom / _Mwab = 1.08.
Furthermore, with respect to the silicone resin composition 1, the evaluation value of the low molecular weight component content calculated from the molecular weight distribution curve at the time of measuring the weight average molecular weight (Mw _com ) was 4.3.

(Example 2)
A viscous silicone resin 5 was obtained in the same manner as in Example 1 except that 15 g of silicone resin 2 and 20 g of silicone resin 3 were used.

  The content of the organic solvent in the viscous silicone resin 5 obtained in the first step was below the lower limit of detection.

  A second step was performed in the same manner as in Example 1 except that 15 g of the silicone resin 5 and the silicone resin 1 were used, and a silicone resin composition 2 of Example 2 was obtained.

When a weight average molecular weight (Mw _ab ) of a mixture of 15 g of silicone resin 2 and 15 g of silicone resin 1 dissolved in THF was measured, it was Mw = 3700 (average value of n = 2).
Moreover, it was Mw = 3900 (average value of n = 2) when the weight average molecular weight ( _Mwcom ) of the silicone resin composition 2 was measured.
That is, _Mwcom / _Mwab = 1.05.
Furthermore, with respect to the silicone resin composition 2, the evaluation value of the low molecular weight component content calculated from the molecular weight distribution curve at the time of measuring the weight average molecular weight (Mw _com ) was 2.3.

(Example 3)
A viscous silicone resin 6 was obtained in the same manner as in Example 1 except that 17.5 g of silicone resin 2 and 25 g of silicone resin 3 were used.

  The organic solvent content in the viscous silicone resin 6 obtained in the first step was below the lower limit of detection.

  A second step was performed in the same manner as in Example 1 except that 7.5 g of the silicone resin 6 and the silicone resin 1 were used, and a silicone resin composition 3 of Example 3 was obtained.

When a weight average molecular weight (Mw _ab ) of a mixture of 17.5 g of silicone resin 2 and 7.5 g of silicone resin 1 dissolved in THF was measured, Mw = 4200 (average value of n = 2) there were.
Moreover, when the weight average molecular weight ( _Mwcom ) of the silicone resin composition 3 was measured, it was Mw = 4500 (average value of n = 2).
That is, _Mwcom / _Mwab = 1.07.
Furthermore, with respect to the silicone resin composition 3, the evaluation value of the low molecular weight component content calculated from the molecular weight distribution curve at the time of measuring the weight average molecular weight (Mw _com ) was 9.5.

Example 4
A colorless and transparent silicone resin composition of Example 4 was prepared by adding 15 g of silicone resin 2 and 10 g of silicone resin 1 to a glass container for a rotary evaporator and heating and stirring at 140 ° C. for 1 hour in a reduced pressure environment of 10 hPa. Product 4 was obtained.

  The content of the organic solvent in the silicone resin composition 4 was not more than the detection lower limit.

When a weight average molecular weight (Mw _ab ) of a mixture of 15 g of silicone resin 2 and 10 g of silicone resin 1 dissolved in THF was measured, it was Mw = 4000 (average value of n = 2).
Moreover, when the weight average molecular weight ( _Mwcom ) of the silicone resin composition 4 was measured, it was Mw = 4200 (the average value of n = 2).
That is, _Mwcom / _Mwab = 1.05.
Furthermore, with respect to the silicone resin composition 4, the evaluation value of the low molecular weight component content calculated from the molecular weight distribution curve at the time of measuring the weight average molecular weight (Mw _com ) was 8.1.

(Comparative Example 1)
15 g of silicone resin 1 and 5 g of silicone resin 2 were placed in an eggplant flask and dissolved by heating and stirring at 100 ° C. for 3.5 hours to obtain a colorless and transparent silicone resin composition 5 of Comparative Example 1.

  The content rate of the organic solvent in the silicone resin composition 5 was 0.2 mass%.

When a weight average molecular weight (Mw _ab ) of a mixture of 5 g of silicone resin 2 and 15 g of silicone resin 1 dissolved in THF was measured, it was Mw = 3300 (average value of n = 2).
Moreover, it was Mw = 3400 (average value of n = 2) when the weight average molecular weight ( _Mwcom ) of the silicone resin composition 5 was measured.
That is, _Mwcom / _Mwab = 1.03.
Furthermore, with respect to the silicone resin composition 5, the evaluation value of the low molecular weight component content calculated from the molecular weight distribution curve at the time of measuring the weight average molecular weight (Mw _com ) was 28.

(Evaluation)
Appropriate amounts of the silicone resin compositions of Examples 1 to 4 and Comparative Example 1 on an LTCC substrate (Low-temperature Co-fired Ceramics, low-temperature co-fired ceramics, manufactured by Yokoo Co., Ltd.) having a length of 3.5 mm and a width of 3.5 mm. Potting (dropping) was performed.

  At the time of potting, the silicone resin compositions 1, 2, 3, and 6 were able to easily form a lens-like convex curved surface at the time of potting because of the thixotropy due to the added silicone resin 3. On the other hand, in the silicone resin compositions 4 and 5, it was difficult to pot thickly.

  Thereafter, the potted silicone resin composition was cured under curing conditions of keeping at 140 ° C. for 10 hours to obtain a cured silicone resin.

  About the obtained silicone resin hardened | cured material, it observed in detail using the digital microscope (Keyence Co., Ltd. VHX-2000). The surface unevenness state of the cured silicone resin and the presence or absence of bubbles in the cured silicone resin were evaluated.

The case where the surface of the cured silicone resin was smooth and the cured silicone resin did not contain any bubbles having a diameter of 10 μm or more was defined as “pass”.
When the surface of the cured silicone resin had irregularities or contained bubbles in the cured silicone resin, it was determined as “Fail”.

  As a result of the evaluation, the cured silicone resin obtained by curing the silicone resin compositions 1 to 4 of Examples 1 to 4 showed no irregularities on the surface, and no bubbles were observed inside the cured silicone resin.

  On the other hand, the cured product obtained by curing the silicone resin composition 5 of Comparative Example 1 had irregularities on the surface, and air bubbles remained in the cured product.

  1 is an appearance photograph of a cured product obtained by curing the silicone resin composition 1 of Example 1, and FIG. 2 is an exterior photograph of a cured product obtained by curing the silicone resin composition 5 of Comparative Example 1. As can be seen from the figure, the cured product of FIG. 1 has no distortion and no surface irregularities in the portion surrounded by a broken line in the center (indicated by α in the figure) compared to the cured product of FIG. .

  As mentioned above, it turned out that this invention is useful.

Claims (7)

A method for producing a silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials,
A method for producing a silicone resin composition, comprising a step of stirring a mixture of the following silicone resin A and the following silicone resin B until the following formula (A) is satisfied.
1.03 <Mw _com / Mw _ab <1.2 (A)
(Mw _ab is the weight average molecular weight of the mixture of the silicone resin A and the silicone resin B, and Mw _com is the weight average molecular weight of the product obtained by the stirring step.)
Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms.
The T3 body means a structural unit in which all three oxygen atoms of the T body in the T body are bonded to other silicon atoms. ) A method for producing a silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials,
A first step of stirring the silicone resin B while heating to 100 ° C. or higher in a reduced pressure environment of 200 hPa or less to obtain a silicone resin B1 having a high molecular weight;
A second step in which the silicone resin A is added to the silicone resin B1 to form a mixture, and then the mixture is stirred while being heated to 100 ° C. or higher in a reduced pressure environment of 200 hPa or less,
In the second step, the method for producing a silicone resin composition in which the mixture is stirred until the following formula (A) is satisfied.
1.03 <Mw _com / Mw _ab <1.2 (A)
(Mw _ab is the weight average molecular weight of the mixture of the silicone resin A and the silicone resin B, and Mw _com is the weight average molecular weight of the product obtained in the second step.)
Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms.
The T3 body means a structural unit in which all three oxygen atoms of the T body in the T body are bonded to other silicon atoms. ) The said 1st process stirs, heating the said silicone resin B and the following silicone resin C to 100 degreeC or more under the pressure reduction environment of 200 hPa or less, and obtains the silicone resin D containing the said silicone resin B1. A method for producing a silicone resin composition.
Silicone resin C: A silicone resin having a mass reduction rate of less than 5% when heated from room temperature to 200 ° C. at a rate of temperature increase of 5 ° C./min and held in air at 200 ° C. for 5 hours. The mass ratio of the said silicone resin A and the said silicone resin B in the said raw material is [silicone resin A]: [silicone resin B] = 10: 90-60: 40, Any one of Claim 1 to 3 The manufacturing method of the silicone resin composition as described in any one of.
(Here, [silicone resin A] represents the mass of the silicone resin A, and [silicone resin B] represents the mass of the silicone resin B.) In the stirring step, the composition containing the mixture is stirred,
The content rate of the organic solvent in the said composition is 1 mass% or less, The manufacturing method of the silicone resin composition of any one of Claim 1 to 4.   The method for producing a silicone resin composition according to any one of claims 1 to 5, wherein in the stirring step, the composition containing the mixture and the reaction promoting catalyst is stirred. A silicone resin composition using the following silicone resin A and the following silicone resin B as raw materials,
Silicone resin composition obtained by GPC measurement, based on a molecular weight distribution curve in which the horizontal axis is the molecular weight in terms of standard polystyrene and the vertical axis is the detection intensity of the differential refractive index detector, the evaluation value obtained by the following method is less than 25 object.
Silicone resin A: A silicone resin in which the structural unit contained is substantially only T-form, the proportion of T3-form in T-form is 60 mol% or more and 90 mol% or less, and the weight average molecular weight is 1500 or more and 8000 or less. .
Silicone resin B: A silicone resin in which the structural unit is substantially only T-form, the proportion of T3-form in the T-form is 30 mol% or more and less than 60 mol%, and the weight average molecular weight is 1500 or more.
(T-form means a structural unit containing a silicon atom bonded to three oxygen atoms.
The T3 body means a structural unit in which all three oxygen atoms of the T body in the T body are bonded to other silicon atoms. )
(Method)
In the molecular weight distribution curve, the vertical axis of the molecular weight distribution curve has a peak top intensity of −1 with respect to a peak having a maximum absolute value among peaks having an intensity of less than 0 and having a molecular weight in the range of 245 to 400. Normalize the value of. Surrounded by the normalized molecular weight distribution curve and a straight line (reference line) represented by a linear expression connecting two points of a molecular weight of 140 and a point of 245 in the normalized molecular weight distribution curve The sum of the normalized detection intensity values in the determined area is obtained as the evaluation value.
(The normalized detection intensity value in the region surrounded by the reference line and the normalized molecular weight distribution curve is determined from the reference line at each molecular weight lined up with a molecular weight interval corresponding to a data acquisition time interval of GPC measurement of 0.3 seconds. It means a value obtained by subtracting the normalized detection intensity value.)