JP3021773B2 - Method of coating inorganic filler with silicone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating a silicone with an inorganic filler using polyorganosilsesquioxane as a main raw material, a powder obtained by the coating method, and an electronic component encapsulating the powder. The present invention relates to a resin composition which is preferably used as a resin and has excellent low-stress properties as well as excellent moisture resistance, heat resistance and moldability.

[0002]

Technical Problem of the Background of the Invention Recently, diodes,
BACKGROUND ART Electronic components such as transistors and integrated circuits are widely sealed using a thermosetting resin. This is because it has an economical advantage that the raw material cost is low and that it is suitable for mass production as compared with the hermetic sealing method using glass and metal ceramics. Among the thermosetting resins, epoxy resins are most commonly used as this type of sealing resin.Especially, epoxy resin compositions containing a novolak type phenol resin as a curing agent include other curing agents. Compared to those using, they are excellent in moldability and moisture resistance, are less toxic, and are inexpensive, and thus have become the mainstream of sealing resin materials.

The requirements for the sealing resin include (a)
The fluidity is good, there is no unfilling, (b) the melt viscosity is low, the bonding wire is not deformed, and (c) the resin burr generated on the lead frame is small. Japanese Unexamined Patent Publication (Kokai) No. 61-101520 discloses a technique in which an organic modified silicone oil such as silicone oil or a copolymer of silicone and polyalkylene oxide is used in combination with a molding resin in order to satisfy such requirements. However, it takes time and effort to uniformly disperse a liquid material such as the silicone oil or the copolymer in a solid epoxy resin or a solid novolak-type phenol resin, and further to an inorganic filler. However, there is a problem that bleeding occurs on the surface of the molded product to contaminate the mold, and that printability on the molded product is deteriorated.

On the other hand, recently, high integration of semiconductor chips has progressed, and the chip size has been increasing accordingly. The package shape has been increased due to the high density mounting on the substrate and the surface mounting. Contrary to the increase in size, there is a tendency to become thinner as seen in flat packages. For this reason, a defect phenomenon that has not been seen in the conventional resin sealing has come to occur. That is, the stress of the resin caused by the difference in the coefficient of thermal expansion between the sealing resin and the chip causes cracks in the passivation film, aluminum wiring slides or sealing due to thermal shock in order to enlarge the chip and reduce the thickness of the sealing resin layer. The package itself is exposed to the solder bath temperature due to surface mounting, causing the package to be exposed to the solder bath temperature, causing the moisture in the package to expand rapidly, causing the package to crack and causing a destructive phenomenon such as cracking the semiconductor. It is a factor that lowers the reliability and eventually lowers the reliability.
Therefore, development of a sealing resin having a small stress and excellent solder bath heat resistance is desired. As a method of reducing such stress, it is conceivable to reduce the coefficient of thermal expansion of the resin to reduce the difference from that of the chip, but the difference between the coefficient of thermal expansion of the resin and that of the chip is large. In this case, a large amount of an inorganic filler having a low coefficient of thermal expansion must be incorporated into the resin, which may impair the moldability.

[0005] On the other hand, in order to cope with the above problem, it has been attempted to add a plasticizer to the resin or use a flexible resin to lower the elastic modulus of the resin to reduce the stress. However, the cured product obtained by this method has a drawback that the heat resistance is low. Further, Japanese Patent Application Laid-Open No. 58-10
No. 8220 proposes a method of imparting crack resistance while maintaining heat resistance by dispersing rubber particles in a sealing resin. However, a cured product obtained by this method is used in a method such as a solder bath. There were difficulties such as poor impact resistance at high temperatures exceeding the glass transition temperature of the sealing resin. Further, JP-A-58-219218 discloses a particulate silicone cured product containing 10% by weight or more of a linear siloxane moiety, and JP-A-59-96122 discloses a silicone emulsion composition in hot air. A method for improving the coefficient of thermal expansion and the internal stress by blending a spherical cured product, which has been spray-cured into an elastomer and cured into an elastomer, into a sealing resin has been proposed. However, these cured products have poor cohesiveness and poor dispersibility, and have low strength and are susceptible to destruction during compounding. Therefore, it was insufficient to improve the above problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has excellent interface adhesion between silicone and an inorganic filler, has a uniform silicone coverage, and is blended with various materials and solvents. Silicone coating method of inorganic filler which can sometimes obtain powder having high dispersibility, powder obtained by the coating method, and resin composition excellent in moisture resistance, heat resistance and moldability as well as low stress The purpose is to provide things.

[0007]

According to the present invention, (A) 100 parts by weight of a polyorganosilsesquioxane and (B) 1 to 10,000 parts by weight of an inorganic filler are kneaded while applying mechanical stress in a molten state, and then cooled and solidified. After that, a method of coating the inorganic filler with silicone characterized by being pulverized into a powdery form, and an average particle diameter of 500 μm or less, wherein the inorganic filler obtained by the coating method is coated with silicone. It relates to powder. The present invention further provides (α) a synthetic resin of 75 to 9.9% by weight, (β) (i) a powder having an average particle diameter of 500 μm or less obtained by coating the inorganic filler according to claim 4 with silicone, and (ii) an inorganic material. 25 to 90.1% by weight of a filler, and the component (β) (i) is 0.1 to 90.1% by weight.
The present invention relates to a resin composition characterized by containing by weight.

According to the method of coating the inorganic filler with the silicone of the present invention, the interface between the silicone and the inorganic filler is excellent, the uniformity of the silicone coverage is high, and the compound exhibits high dispersibility when blended with various materials and solvents. Powder can be obtained. In addition, since the powder obtained by this coating method has the above-described characteristics, when used as a modifier for various materials, the modifying function of silicone can be more effectively exhibited. Furthermore, the resin composition according to the present invention has an improved stress property and heat resistance without impairing properties such as moisture resistance and moldability of the base resin by blending an appropriate amount of the powder and the inorganic filler. As a result, it is possible to easily obtain a resin molded product having good moldability, low stress, moisture resistance, heat resistance and the like.

First, before describing the method of coating the inorganic filler with silicone according to the present invention, the polyorganosilsesquioxane as component (A) as a raw material will be described. The polyorganosilsesquioxane of the component (A) used in the present invention is a main polymer component for applying a silicone coating to an inorganic filler, and is the most important component for achieving the present invention. As the polyorganosilsesquioxane, first, a silanol group-containing polyorgano system comprising R ¹ SiO _1.5 (wherein R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group and / or a polyfluoroalkyl group) And silsesquioxane. The R ¹ silanol group-containing organopolysiloxane polysilsesquioxane R ¹ Sun represented by SiO _1.5 units include a methyl group, an ethyl group, a propyl group, an alkyl group such as butyl group, vinyl group, an alkenyl group such as allyl; phenyl An aryl group such as an isopropenylphenyl group; a cycloalkyl group such as a cyclohexyl group;
Or a chloromethyl group in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, etc., a 3,3,3-trifluoropropyl group, a cyanomethyl group; A monovalent hydrocarbon group exemplified by an N-β-aminoethyl-γ-aminopropyl group, a γ-aminopropyl group, and the like, and these hydrocarbon groups may be used alone or as a mixture. The silanol group-containing organopolysilsesquioxane can be obtained by a known method in which a hydrolyzable silane, for example, an organotrichlorosilane or an organotrialkoxysilane is hydrolyzed and condensed with excess water. Such silanol group-containing organopolysesquioxane has a molecular weight of 1000
The above (in terms of standard polystyrene), preferably 2000 or more, more preferably 6000 or more is good. Molecular weight 10
If it is less than 00, a large amount of low-boiling substances is distilled off when the inorganic filler is coated, which is not preferable. If it is less than 2,000, although low-boiling substances are hardly distilled, the components are not uniformly mixed and dispersed because moderate stress is not applied to the mixture of the polyorganosilsesquioxane and the inorganic filler. It may not be possible to apply a suitable silicone coating.

[0010] Further, in order to suppress the condensation reaction between the silanol groups that occurs during melt-kneading, to suppress the interfacial adhesion with the inorganic filler, and to improve the pulverizability of the finally obtained bulk kneaded material. As the component (A), triorganosilylated polyorganosilsesquioxane can also be used. The tri-organo silylated polyorganosilsesquioxane, to the of R ¹ consists of SiO _1.5 units silanol-containing polyorganosilsesquioxane ((a) component) 100 parts by weight, (R ² ₃ Si) _a Z (where
R ² represents an unsubstituted monovalent hydrocarbon group and / or a polyfluoroalkyl group, a represents 1 or 2, and Z represents a hydrogen atom, a halogen atom, a hydroxyl group, —OR ′, —NR when a is 1. '
X, -ONR ' ₂ or -OOCR', when a is 2, -O-, -N
Represents (X)-or -S-. However, here, R ′ has 1 to 1 carbon atoms.
X represents 4 alkyl groups, and X represents a hydrogen atom or 1 carbon atom
To 4 alkyl groups) (component (b)) in an amount of 5 to 100 parts by weight to block the silanol group of component (a).

In this case, the molecular weight of the silanol-containing polyorganosilsesquioxane (a) is 1000 or more (in terms of standard polystyrene), preferably 2000 or more, and more preferably 6000 or more. If the molecular weight is less than 1,000, a compound obtained by triorganosilylation of a silanol group is not only liquid at room temperature but also contains a large amount of volatile components, which is not preferable. If the molecular weight is less than 2000, the triorganosilylated compound has almost no volatile components, but may not become solid at room temperature, making it difficult to use the inorganic filler in the silicone coating method of the present invention.

The unsubstituted monovalent hydrocarbon group for R ² represented by component (b) represented by (R ² ₃ Si) _a Z is the same as the above-mentioned R ¹ and includes a methyl group and an ethyl group. Alkyl groups such as propyl, butyl and the like; alkenyl groups such as vinyl and allyl; aryl groups such as phenyl and isopropenylphenyl; cycloalkyl groups such as cyclohexyl; N-β-aminoethyl-γ-substituted by substituting a chloromethyl group, a 3,3,3-trifluoropropyl group, and a cyanomethyl group in which part or all of the hydrogen atom substituted by a halogen atom, a cyano group, and the like; It is a monovalent hydrocarbon group exemplified by an aminopropyl group, a γ-aminopropyl group and the like. (b) As the compound of the general formula (R ² ₃ Si) _a Z of the component, trimethylsilane, triethylsilane, trimethylchlorosilane, trimethylsilanol, trimethylmethoxylane, trimethylethoxysilane, hexamethyldisilazane, (CH ₃ ) ₃ SiNHCH ₃ ,
_{(CH 3) 3 SiNHC 2 H} 5, (CH 3) 3 SiN (CH 3) 2, (CH 3) 3 SiN (C
_{2 H 5) 2, (CH} 3) 3 SiOCOCH 3, CF 3 (CF 2) 2 (CH 2) 2 Si (CH 3) 2 OCH
₃ , CF ₃ (CF ₂ ) ₂ (CH ₂ ) ₄ Si (CH ₃ ) ₂ OCH ₃ , CF ₃ (CF ₂ ) ₂ (CH ₂ ) ₇ S
i (CH ₃ ) ₂ OCH ₃ , (CF ₃ (CH ₂ ) ₂ (CH ₃ ) ₂ Si) ₂ NH, (CF ₃ (C
_{F 2) 5 (CH 2)} 2 (CH 3) 2 Si ] ₂ NH, and the like can be exemplified. Of the above, silazanes or chlorosilanes are preferable among them because they can easily remove unreacted substances after the silylation reaction, and may be used alone or in combination of two or more.

The silylation reaction of the silanol group-containing polyorganosilsesquioxane with silazanes or chlorosilanes proceeds easily only by mixing the respective required amounts and heating, so that there is no particular problem. The desired triorganosilylated polyorganosilsesquioxane can be obtained.

The amount of the silylating agent of the component (b) used per 100 parts by weight of the component (a) depends on the molecular weight of the component (a) (that is, the amount of residual silanol), but is preferably 5 to 100 parts by weight. If the amount is less than 5 parts by weight, sufficient silylation cannot be carried out, resulting in gelation during the silylation reaction, or impairment of the thermal stability of the obtained silicone compound even without gelation. If it exceeds 100 parts by weight, unreacted component (b) remains as an excess, and
It takes a long time to remove this excess. Moreover, it is economically disadvantageous.

The silylation reaction may be carried out in an organic solvent in order to control the reaction temperature or to suppress a side reaction of dehydration condensation. Such solvents include hydrocarbon solvents such as toluene, xylene, hexane, industrial gasoline, mineral spirits and kerosene; ether solvents such as tetrahydrofuran and dioxane; chlorinated hydrocarbon solvents such as dichloromethane and dichloroethane. can give. Such a reaction is not particularly limited, but the temperature may vary depending on the type or amount of the solvent used, and may be arbitrarily determined in the range of room temperature to 200 ° C. Hydrochloric acid, ammonia or ammonium chloride generated by the silylation reaction can be removed by washing with water or simultaneously with the solvent used for controlling the reaction temperature.

As the polyorganosilsesquioxane of the component (A), the silanol group-containing polyorganosilsesquioxane and the triorganosilylated polyorganosilsesquioxane may be used alone or in combination. It can be used by mixing in a ratio. In addition, when performing the silicone coating of the present invention, the obtained bulk kneaded material is pulverized into a powder at room temperature, and in consideration of handling as a powder, it is composed of this single or several types of mixtures.
The softening point of the polyorganosilsesquioxane (A) is preferably 50 ° C. or higher.

On the other hand, the inorganic filler of the component (B) used in the method of coating the inorganic filler according to the present invention with silicone includes, for example, silica powder, alumina, antimony trioxide, silicon nitride, silicon carbide, zinc oxide, Iron oxide, iron powder, cobalt powder, nickel powder, carbon black,
Examples include talc, calcium carbonate, titanium oxide, clay, asbestos, mica, redwood, glass fiber, carbon fiber, and the like. Among them, silica powder or alumina is preferred. One of these inorganic fillers may be used alone, or two or more thereof may be used in combination.

The above components are used in an amount of (B) based on 100 parts by weight of the polyorganosilsesquioxane (A).
The content of the inorganic filler as a component is in the range of 1 to 10,000 parts by weight, and the usage ratio thereof can be appropriately selected according to the properties to be imparted to the filler by the silicone film.

Further, within a range not to impair the effects of the present invention,
Use of various pigments, heat-resistant agents, adhesion improvers, etc.
it can. For example, to improve the flexibility of the silicone component
Or improve the releasability of the kneaded material from the melt kneading device
Compound polyorganosiloxane for such purposes
And effective. With such a polyorganosiloxane
Is the general formula R^Three _bSiO_{4-b / 2}  (Where R^ThreeIs a substituted or unsubstituted monovalent organic group, and b is 1.
80 to 2.02). This poly
Organosiloxane structure is linear, branched or cyclic
Although not particularly limited, those having a linear structure are preferred.
The molecular weight is not particularly limited.
Weight average molecular weight of 1 × 10^Three~ 1 × 10⁶Range of
Are preferred.

The substituted or unsubstituted monovalent hydrocarbon group contained in the polyorganosiloxane includes, for example, a methyl group, an ethyl group, a propyl group, a vinyl group, a phenyl group, and a halogen atom or a cyano group. And the molecular chain terminals of the polyorganosiloxane may be, for example, a hydroxyl group, an alkoxy group, a trimethylsilyl group, a dimethylvinylsilyl group, a methylphenylvinylsilyl group,
Those blocked with a methyldiphenylsilyl group or the like can be mentioned.

Examples of the pigment include titanium white, titanium yellow, and red iron, and examples of the heat-resistant agent include cerium hydroxide, cerium oxide, iron oxide, and titanium oxide. Furthermore, as an adhesion improver,
For example, an organic silicon compound having both an amino group, a mercapto group, an epoxy group or an alkenyl group and an alkoxysilyl group can be used.

Next, a method of coating the inorganic filler with silicone according to the present invention will be described. The method comprises the steps of:
Mechanical stress to the extent that each component is uniformly mixed and dispersed in a molten state with the component polyorganosilsesquioxane, the inorganic filler (B), and other components used as necessary. After kneading and solidifying by cooling,
Pulverizing into a powder. For the kneading, a roll, a kneader, a Banbury mixer, or the like is used, and for the pulverization, a jet mill, a ball mill, a hammer mill, or the like can be used. The kneading is carried out in a temperature range from [softening point] to [softening point + 50 ° C.] of the polyorganosilsesquioxane, more preferably in a temperature range from [softening point] to [softening point + 30 ° C.]. The pulverization is preferably carried out at a temperature at which the polyorganosilsesquioxane can be cooled and solidified at a temperature of [softening point of -20 ° C] or lower, more preferably at a temperature of [softening point of -30 ° C] or lower. When kneading at a high temperature exceeding [softening point + 50 ° C], sufficient mechanical stress cannot be applied to each component.
Further, pulverization at a temperature higher than [softening point-20 ° C] is not preferable because there is a possibility that some fusion may occur between pulverized particles due to a rise in temperature during pulverization.

Next, the powder of the present invention will be described. The powder of the present invention has an amorphous particle size of 500 μm or less, which is obtained by the above-described method of coating the inorganic filler with silicone. Further, the degree of silicone treatment of the inorganic filler may not be uniform. For example, the filler particles may be completely silicone-coated, partially silicone-coated, or a mixture of particles composed of silicone alone. . However, those mixed with an inorganic filler which is not coated with silicone at all are not preferable because, when dispersed in an organic solvent, the dispersibility is not sufficiently improved and the particle sedimentation is not sufficiently suppressed.

Next, the components constituting the resin composition according to the present invention will be described. The synthetic resin of the component (α) used in the present invention is a base polymer in the composition. Examples of such a synthetic resin include styrene, AS, ABS, polyvinyl chloride, and vinylidene chloride.
Vinyl chloride copolymer resin, polyethylene, polypropylene, polyacetal, polyamide, polycarbonate,
Polyethylene terephthalate, polybutylene terephthalate, epoxy resin, phenol resin, polyester resin, urea resin, melamine resin, diallyl phthalate resin, formaldehyde resin, xylene resin, xylene formaldehyde resin, ketone formaldehyde resin, furan resin, urea resin, imide resin, melamine Resin, alkyd resin, unsaturated polyester resin, aniline resin,
Examples thereof include sulfonamide resins, silicone resins, and copolymer resins thereof. Among them, epoxy resin is one of preferred ones. As long as the epoxy resin is a compound having at least two epoxy groups in its molecule, its molecular structure, molecular weight and the like are not particularly limited, and generally used ones can be widely used. Examples of the epoxy resin include bisphenol type aromatic resins, alicyclic resins such as cyclohexane derivatives, and epoxy novolak resins represented by the following general formula.

[0025]

Embedded image

As the component (α), one type may be used alone, or two or more types may be used in combination.

The powder obtained by coating the inorganic filler of the component (β) (i) with silicone is a powder obtained by the above-mentioned processing method, and is the most important component for achieving the object of the present invention. is there. The powder of the component (β) (i) is prepared by coating the above-mentioned coating method with 1 to 10,000 parts by weight of the inorganic filler of the component (B) in 100 parts by weight of the polyorganosilsesquioxane of the component (A). Silicone coated. The average particle size of this powder is 500 μm or less, preferably 300 μm or less. If it exceeds 500 μm, the resin composition is inferior in moldability due to poor dispersibility of the powder, and sufficient effects such as low stress property and moisture resistance cannot be exhibited.

The inorganic filler of the component (β) (ii) is a component that contributes to imparting mechanical strength to the resin molded product, and includes silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium carbonate, and the like. Examples include white, clay, asbestos, mica, red iron, glass fiber, carbon fiber, and the like. Among them, silica powder or alumina is preferred. One of these inorganic fillers may be used alone, or two or more thereof may be used in combination.

The compounding amount of the powder obtained by coating the inorganic filler of the component (β) (i) with silicone and the inorganic filler of the component (β) (ii) is such that the total amount thereof is 25.0 to 90.1% by weight and the powder of the component (β) (i) in the resin composition
It is selected in the range of 0.1 to 90.1% by weight. If the total amount of both components is less than 25.0% by weight, or if the amount of the powder of the component (β) (i) is less than 0.1% by weight,
The effect of improving low stress, thermal shock resistance, heat resistance and moisture resistance is small. Conversely, if the total amount of both components or the compounding amount of (β) (i) component exceeds 90.1% by weight, the moldability is poor. Becomes

The resin composition according to the present invention contains the above (α)
In addition to the component and the (β) component, if necessary, natural waxes, synthetic waxes, metal salts of linear fatty acids, release agents such as acid amides or esters or paraffins, chlorinated paraffins, bromtoluene And a flame retardant such as hexabromobenzene and antimony trioxide, a coloring agent such as carbon black and red iron oxide, and a silane coupling agent. If necessary, tertiary amines, imidazoles, organic phosphine compounds, metal chelates, and the like can be blended as a curing aid for the thermosetting resin. Of these, organic phosphine compounds are preferred.

As a general method for producing the resin composition according to the present invention, the following method can be applied. That is, the components (α) and (β) of the present invention, and other components to be blended as necessary, are mixed by a mixer or the like so as to be uniform, and then subjected to a melt kneading treatment using a hot roll or a kneader, and then This is a method of pulverizing the cooled and solidified material into an appropriate size, or a method of uniformly kneading with a mixer or the like, melt-kneading with an extruder, and pelletizing.

[0032]

The present invention will be described below with reference to examples. In the examples, all “parts” represent “parts by weight”, and all “%” represent “% by weight”.

First, a polyorganosilsesquioxane was prepared as follows. Reference Example-1 A mixture of 1 mol of methyl isopropoxysilane and 150 parts of toluene was weighed into a flask, and 108 parts of a 1% aqueous hydrochloric acid solution was added dropwise to the mixture over 20 minutes to hydrolyze methyl triisopropoxy silane. After 40 minutes from the dropping, stirring was stopped, and a mixed solution of water and isopropyl alcohol in the lower layer containing a small amount of hydrochloric acid separated into two layers was separated, and then the remaining hydrochloric acid of the resin solution of toluene was removed by washing with water. Toluene was removed under reduced pressure to prepare silanol group-containing polymethylsilsesquioxane P-1 having a molecular weight of 12000 and a softening point of 115 ° C. Next, the silanol group-containing polymethylsilsesquioxane
100 parts, toluene 200 parts, trimethylchlorosilane 10
And 50 parts of hexamethyldisilazane were weighed into a flask, and heated and stirred. At the reflux temperature of toluene, 2
After heating and stirring for a period of time, ammonia, hydrochloric acid or salts thereof produced by the reaction were removed by washing with water, and toluene was further removed under reduced pressure to obtain a trimethylsilylated silicone compound A-1 having a softening point of 80 ° C.

Reference Example 2 A silanol group-containing polymethylsilsesquioxane P-2 having a molecular weight of 2000 was obtained in the same manner as in Preparation Example 1 except that a 0.5% aqueous hydrochloric acid solution was used. Further, P-2 was trimethylsilylated in the same manner as in Reference Example 1 to obtain a trimethylsilylated silicone compound A-2 having a softening point of 10 ° C. Further, the weight ratio of the trimethylsilylated silicone compound A-1 obtained in Reference Example-1 to the trimethylsilylated silicone compound A-2 having a softening point of 10 ° C. obtained here was 1: 1.
A mixture with a softening temperature of 60 ℃
Got 3 In addition, the measuring method of a softening point and a molecular weight is as follows. Measuring method of softening point: According to the ring and ball softening point measuring method of JIS C 2104. Measurement of molecular weight… GPC (Tosoh,
HLC-802U) to make a calibration curve with standard polystyrene,
The molecular weight was determined.

Preparation Example 1 Silanol Group-Containing Polymethylsilsesquioxane P-15
Parts and fused silica powder (average particle size 5 μm, particle size distribution 1
1010 μm) 75 parts were melt-kneaded with a Banbury mixer set at 120 ° C. at 60 rpm for 5 minutes, cooled and solidified, pulverized using a jet mill pulverizer, and coated with silicone-coated powder C-1 having an average particle diameter of 8 μm. I got The following devices were used for measuring the average particle size and the particle size distribution of the silicone-coated powder. Centrifugal Automatic Particle Anaryzer manufactured by HORIBA Preparation Examples 2 to 10 Silicone-coated powders C-2 to C-10 were obtained in the same manner as in Preparation Example 1 except that the components shown in Table 1 were used. Table 1 shows the measurement results of the average particle size of the thus obtained silicone-coated powder. Preparation Examples 11 and 12 The same components as in Preparation Examples 1 and 3 were used at 150 ° C.
The melt kneading was carried out at 60 rpm for a long time using a Banbury mixer set in the above. As a result, in the component system of Preparation Example 1 (Preparation Example 11), the mixer torque continued to increase during kneading, and after 1 hour, a granular material having a particle size of about 1 to 10 mm was obtained. An attempt was made to finely grind the granules using a jet mill grinder, but it was very hard and impossible. On the other hand, in the component system of Preparation Example 2 (Preparation Example 12), the mixer torque did not change even after 2 hours of melt-kneading. At this point, the mixture was cooled and solidified, and pulverized using a jet mill pulverizer. As a result, a silicone-coated powder C-12 having an average particle size of 8 μm was obtained. Preparation Example 13 Silanol group-containing polymethylsilsesquioxane P-1 32
Parts, 8 parts of hydroxyl-terminated polydimethylsiloxane having a degree of polymerization of 8000 and 40 parts of wet silica (Nip Seal LP; manufactured by Nippon Silica Co., Ltd.) were melt-kneaded at 60 rpm for 5 minutes in a Banbury mixer set at 120 ° C., and cooled and solidified. Thereafter, the mixture was pulverized using a jet mill pulverizer to obtain a silicone-coated powder C-13 having an average particle diameter of 4 μm. The powder thus obtained
When 80 g of toluene was added to 20 g of C-13 and mixed, a suspension in which powder was uniformly dispersed was obtained. Further, when the change with time was tracked by measuring the turbidity of the powder, it took one week for 10% of the total amount of the powder to completely settle. For comparison, the above silsesquioxane P-18
When 2 parts of polydimethylsiloxane, 10 parts of wet silica and 80 g of toluene were mixed, most of the silsesquioxane remained without dissolving, and all of the wet silica precipitated immediately after mixing.

[0036]

[Table 1]

Example 1 170 parts of o-cresol novolak type epoxy resin (epoxy equivalent: 200, abbreviated as epoxy resin): 170 parts, novolak type phenol resin (hydroxyl equivalent: 103): 90 parts, silicone-coated powder C-1 150 parts, fused silica Powder (average particle size 5μm) 574
Parts, triphenylphosphine (abbreviated as additive-1) 3
Parts, 5 parts of red phosphorus (abbreviated as additive-2), 1 part of carbon black (abbreviated as additive-3), 3 parts of carnauba wax (abbreviated as additive-4), and γ-glycidoxypropyltri 4 parts of methoxysilane (abbreviated as additive-5)
Using a Henschel mixer, the mixture was stirred and mixed at a rotation speed of 3000 rpm so as to be uniform for 5 minutes. The mixture is then
The mixture was melt-kneaded with a hot roll set at 80 to 100 ° C. for 3 minutes, cooled, and then pulverized to obtain a resin composition. The thermal expansion coefficient, bending elastic modulus, and spiral flow of the molded article using the resin composition thus obtained were measured, and the moisture resistance, thermal shock resistance, solder bath heat resistance, and distortion characteristics were measured. Such a result was obtained.

The measurement or test method is as follows. Coefficient of thermal expansion: According to a measuring method based on ASTM-D696, after transfer molding the resin composition at 170 ° C. for 3 minutes, the resin composition was left in an atmosphere at 180 ° C. for 8 hours to proceed with curing.
It measured about the obtained hardening test body. Flexural modulus: measured according to JIS-K6911. Spiral flow: Measured according to EMMI-1-66. Moisture resistance test: An electric component having two aluminum wirings was transfer-molded at 170 ° C. for 3 minutes using the resin composition, and then cured at 180 ° C. for 8 hours. A moisture resistance test was performed on the obtained 100 electrical components in high-pressure steam at 120 ° C., and the moisture resistance was evaluated based on the time at which 50% disconnection (defect occurrence) due to aluminum corrosion occurred. Thermal shock resistance cycle test: In the same manner as in the case of the humidity resistance test, a test molded product of 30 × 25 × 5 mm was prepared. Next, a copper plate of 25 × 25 × 3 mm was buried in the bottom surface of these test molded articles, and alternately placed in a constant temperature bath at −40 ° C. and 200 ° C. for 30 minutes. The thermal shock resistance was evaluated by obtaining the ratio of the molded products, ie, the number of cracked molded products / the total number of molded products. Solder bath heat resistance test: An electric component having two aluminum wirings was adhered to a normal 42 alloy frame using a resin composition, and transfer molded at 170 ° C. for 3 minutes to form a 5 × 10 × 1.5 mm. Was obtained. The molding was then cured at 180 ° C. for 8 hours.
Next, the molded article was left in an atmosphere at a temperature of 40 ° C. and a relative humidity of 90% for 100 hours to perform a moisture absorbing treatment, and then immersed in a solder bath at 250 ° C. for 10 seconds. Thereafter, a pressure cooker test was performed in saturated steam at 127 ° C. and 2.55 atm. Those broken by aluminum corrosion were counted as defective products, and the solder bath heat resistance was evaluated based on the number of defective products / the total number of molded products. Strain test: A commercially available storage gauge was adhered to the island portion of a DIP 16-pin lead frame, and the strain was measured after curing at 180 ° C. for 8 hours. Adhesion: Use aluminum as test piece material, 18
Specimens obtained under the curing conditions of 0 ° C. and 8 hours were subjected to JIS-K 6850
It measured according to.

Examples 2 to 12, Comparative Examples 1 and 2 Resin compositions were obtained in the same manner as in Example 1 except that the components shown in Table 2 were used. Table 3 shows the results of the evaluation of the resin composition thus obtained in the same manner as in Example 1.

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

As described above, the method for coating the inorganic filler with the silicone according to the present invention provides excellent interface adhesion between the silicone and the inorganic filler, high uniformity in the degree of silicone coverage, and is suitable for various materials and solvents. At the time of compounding, a powder exhibiting high dispersibility can be obtained.

Further, since the powder obtained by this coating method has the above-mentioned properties, when used as a modifier for various materials, the modifying function of silicone is more effectively exhibited. be able to. Furthermore, the resin composition according to the present invention is improved in stress properties and heat resistance without impairing properties such as moisture resistance and moldability of the base resin by blending the powder and the inorganic filler in appropriate amounts. It is possible to obtain a resin molded product having good moldability and excellent in low stress property, moisture resistance, heat resistance and the like. Therefore, for example, when low-pressure transfer molding is performed as a sealing resin material, there is no unfilling, and problems such as open bonding wires, resin cracks, and pellet cracks do not occur. Further, even after immersion in a solder bath at 250 ° C. or higher, it is possible to provide a highly reliable electronic / electric component without deterioration in properties such as moisture resistance and mechanical strength.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yutaka Horie 6-2-31 Roppongi, Minato-ku, Tokyo Toshiba Silicone Co., Ltd. (56) References JP-A-60-229945 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) C09C 3/12 C08K 9/06

Claims (3)

(57) [Claims] (1) (A) polyorganosilsesquioxane
100 parts by weight and (B) 1 to 1000 parts by weight of an inorganic filler are kneaded while applying mechanical stress in a molten state, cooled and solidified, and then pulverized into a powder. Silicone coating method. (2) The polyorganosilsesquioxane of (A) is
The silanol group-containing polyorganosilsesquioxane comprising units of R ¹ SiO _1.5 (wherein R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group and / or a polyfluoroalkyl group). Silicone coating method of inorganic filler. 3. The polyorganosilsesquioxane of (A) is a component (a) R ¹ SiO _{1.5 wherein} R ¹ is a substituted or unsubstituted monovalent hydrocarbon group and / or a polyfluoroalkyl group. against silanol-containing polyorganosilsesquioxane compound 100 parts by weight of the expressed) units, (b) component (R ² in ₃ Si) _a Z (wherein, R ² is and monovalent hydrocarbon radical unsubstituted / Represents a polyfluoroalkyl group, a represents 1 or 2,
Z is a hydrogen atom, a halogen atom, a hydroxyl group, -O when a is 1.
Represents R ', -NR'X, -ONR' ₂ or -OOCR ', when a is 2
Represents -O-, -N (X)-or -S-. Wherein R ′ represents an alkyl group having 1 to 4 carbon atoms, X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and 5 to 100 parts by weight of a compound represented by the formula The method of claim 1, wherein the silanol group of the component (a) is blocked.