JP2003181988A - Insulated expanded silicone sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulated expanded silicone sheet with such advantages that the tolerance of its use range can be made high and its application for use to low-strength electric/electronic equipment and the like is possible and further, its sufficient compression performance can be expected with the improvement of its ease of handling. <P>SOLUTION: This insulated expanded silicone sheet has an insulating silicone foam 1 and a pair of support sheets 10 integrally laminated and bonded to both face and back of the silicone foam 1. In addition, the silicone foam 1 is molded into an interconnecting cell-type foam by using a silicone rubber material containing 100 pts.wt. of a heat-durable organopolysiloxane composition, 0.1 to 30 pts.wt. of microfiller of a thermally expandable unexpanded organic resin or microhollow filler of an expanded organic resin and 0.5 to 50 pts.wt. of a polyhydric alcohol and one kind or at least two kinds of its derivative. Further, each support sheet 10 is made of an insulating silicone rubber sheet. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating foamed silicone sheet used as a packing material between a liquid crystal display glass and a case or between electronic circuit boards.

[0002]

2. Description of the Related Art A molded product is used as a packing material for mobile phones and the like, and as this molded product, a silicone foam excellent in heat resistance, solvent resistance and electric insulation is suitable. Therefore, conventionally, silicone is foamed to foam an insulating silicone foam, and a molded body made of this silicone foam is used as a packing material. In the conventional silicone foam 1A, a silicone compound, a vulcanizing agent, a foaming agent such as 2,2-azobisisobutyronitrile is used as a foaming agent, and a gas is generated when heat is applied to the foaming agent. It is molded by accumulating the generated gas inside. The silicone foam 1A molded in this way is, as shown in FIG.
Basically, the space 2A is a single foam type of single foam, and has a structure in which air does not flow to the outside.

[0003]

Since the conventional silicone foam 1A generates gas when heat is applied to the foaming agent as described above, foaming control is required unless the temperature during molding is strictly controlled. Is extremely difficult, and
Along with this difficulty in foaming control, the withstand load changes depending on the site of the silicone foam 1A, so there is a problem that the use range tolerance must be narrowed. In addition, the conventional silicone foam 1A is a single-cell type, and since the single-foaming space 2A does not allow air to flow to the outside, a change in volume cannot be expected. As a result, there is a problem that a heavy load is applied and it is difficult to use the electric and electronic device with low mechanical strength in peace.

Further, since the air does not circulate with the outside, the internal air exerts a bad influence on the compression, and a sufficient compression performance cannot be expected. In particular, since the compression set characteristic is about 10 to 20%, a sufficient reaction force cannot be generated at the time of compression, and it must be used in an overcompressed state.
Furthermore, since the silicone foam 1A lacks rigidity, there is a problem in that the handleability is really poor.

The present invention has been made in view of the above, and can be used in wide range of use tolerance, can be used in electric and electronic equipment having low mechanical strength, and can be expected to have sufficient compression performance. It is an object of the present invention to provide an insulating foamed silicone sheet which can be improved in handleability.

[0006]

Means for Solving the Problems The present inventor has made a hollow filler contained in a silicone rubber, and heats it as it is to form a foam, and at the same time, a hole is made in a shell of the hollow filler at the time of this formation. The present invention has been completed by finding that the above problems can be solved by forming continuous cells. In order to achieve the above object, the invention according to claim 1 comprises an insulating silicone foam and a support sheet provided on at least one surface of the silicone foam, the silicone foam. 100 parts by weight of a thermosetting organopolysiloxane composition, a heat-expandable unexpanded organic resin fine filler or an expanded organic resin fine hollow filler 0.1 to 30
It is molded by using a silicone rubber material containing 0.5 to 50 parts by weight of polyhydric alcohol and one or more of polyhydric alcohol and its derivative, and the support sheet is an insulating silicone rubber sheet. I am trying.

The average particle diameter of the fine hollow filler contained in the silicone rubber material is preferably 10 to 200 μm. Further, it is preferable that the compression set characteristic of the silicone foam is 3 to 8% and the compression set characteristic of the support sheet is 4 to 11%.
Further, the support sheet may have a thickness of 5 to 50% with respect to the thickness of the silicone foam.

Here, the support sheet in the claims may be provided on one side of the silicone foam or on both sides of the silicone foam. INDUSTRIAL APPLICABILITY The insulating foamed silicone sheet according to the present invention can be widely used as packing materials, spacers, balancers and the like for mobile phones, information terminal devices, electric and electronic circuit devices.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will be described below with reference to the drawings. An insulating foamed silicone sheet in this embodiment has a substantially plate-shaped cross section as shown in FIGS. The silicone foam 1 is provided with an insulating silicone foam 1 and a pair of support sheets 10 that are integrally laminated and adhered to both front and back surfaces of the silicone foam 1, and the silicone foam 1 is formed by (A) thermosetting organopolysiloxane. 100 parts by weight of the composition, (B) 0.1 to 30 parts by weight of a heat-expandable unexpanded organic resin microfiller or expanded organic resin microhollow filler, and (C) polyhydric alcohol and its derivative An insulative silicone rubber sheet in which each support sheet 10 is molded into an open-cell type using a silicone rubber material containing one or two or more 0.5 to 50 parts by weight and has a substantially plate-shaped cross section. So that the door.

The (A) component thermosetting organopolysiloxane composition forming the silicone foam 1 is an addition reaction-curable organopolysiloxane composition or an organic peroxide-curable organopolysiloxane composition. Is preferred. In this case, the addition reaction-curable organopolysiloxane composition is (1) 100 parts by weight of an organopolysiloxane having an average of 2 or more alkenyl groups in one molecule (2) An average of 2 or more silicon atoms in one molecule. It is preferable that the organohydrogenpolysiloxane having a hydrogen atom bonded to 0.1 to 50 parts by weight (3) addition reaction catalyst comprises a catalytic amount.

The organic peroxide-curable organopolysiloxane composition is (i) 100 parts by weight of organopolysiloxane having an average of two or more alkenyl groups in one molecule (ii) Organic peroxide It is preferable that

As the organopolysiloxane of (1) having an average of two or more alkenyl groups in one molecule, those represented by the following average composition formula (1) can be used. R ¹ _a Sio _{(4-a) / 2} Formula (1) (In the formula, R ¹ is the same or different from each other and has 1 to 10 carbon atoms, preferably 1 to 8 unsubstituted or substituted monovalent hydrocarbon group, a is a positive number in the range of 1.5 to 2.8, preferably 1.8 to 2.5, more preferably 1.95 to 2.05)

The unsubstituted or substituted monovalent hydrocarbon group bonded to the silicon atom represented by R ¹ is, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, Benchle base,
Alkyl groups such as neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, decyl group, aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, phenylethyl group, phenylpropyl group, etc. Alkenyl groups such as aralkyl group, vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group, cyclohexenyl group and octenyl group,
Some or all of the hydrogen atoms of these groups are fluorine, bromine,
Those substituted with a halogen atom such as chlorine, a cyano group, etc., such as a chloromethyl group, a chloropropyl group, a bromoethyl group, a trifluoropropyl group, a cyanoethyl group and the like can be mentioned.

In this case, at least two of R ¹ must be alkenyl groups (in particular, those having 2 to 8 carbon atoms are preferable, and those having 2 to 6 carbon atoms are more preferable). The content of this alkenyl group is in all the organic groups bonded to the silicon atom (that is, in the unsubstituted or substituted monovalent hydrocarbon group as R ¹ in the above average composition formula (1)).
It is preferably 0.001 to 20 mol%, particularly 0.01 to 10 mol%. This alkenyl group may be bonded to a silicon atom at the end of the molecular chain, may be bonded to a silicon atom in the middle of the molecular chain, or may be bonded to both of them, but the organopolysiloxane according to the present invention is It preferably contains at least an alkenyl group bonded to a silicon atom at the terminal of the molecular chain.

The structure of the organopolysiloxane is usually
The main chain consists of repeating diorganosiloxane units,
The diorganopolysiloxane is basically a linear structure in which both ends of the molecular chain are blocked with a triorganosiloxane group, but it may have a partially branched structure, a cyclic structure or the like. There is no particular limitation on the degree of polymerization (or viscosity) of this alkenyl group-containing organopolysiloxane, and it can be used from a low degree of polymerization that is liquid at room temperature (25 ° C) to a high degree of polymerization that is gum-like (gum-like). Usually, the average degree of polymerization (weight average degree of polymerization) is 50 to 20,000, and preferably 100 to 20,000.
10,000, more preferably about 100 to 2,000 is used. The reason why the average degree of polymerization is 50 or more is that when the average degree of polymerization is less than 50, the physical properties of the rubber as a cured product may be insufficient.

The organohydrogenpolysiloxane as the component (2) is represented by the following average compositional formula R ² _b H _c SiO ₍₄ - _b - _{c) / 2} (2) and has at least 2 in one molecule. Individual (usually 2-300
Number), preferably 3 or more, more preferably 3 to 150
Number of silicon-bonded hydrogen atoms (ie SiH groups)
It is necessary to have

In the formula (2), R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. For this R ² ,
The same groups as R ¹ above can be mentioned. b is 0.7-2.
1, c is 0.001 to 1.0, bc is 0.8 to 3.0
Is a positive number, preferably b is 1.0 to 2.0, c
Is preferably 0.01 to 1.0 and bc is preferably 1.5 to 2.5.

At least 2, preferably 3 in one molecule
The SiH groups contained in a number of not less than one may be located at the terminal of the molecular chain, in the middle of the molecular chain, or at both of them. The molecular structure of the organohydrogenpolysiloxane may be linear, cyclic, branched or three-dimensional network structure, but the number of silicon atoms in one molecule (or the degree of polymerization) is usually 2 to 300. , Preferably 4 to 1
It is desirable that about 50 pieces are liquid at room temperature (25 ° C).

Specific examples of the organohydrogenpolysiloxane of the formula (2) include 1,1,3,3-tetramethyldisiloxane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer. , Both ends trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends dimethylhydrogensiloxy group blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy group blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both Methyl hydrogen siloxane / diphenyl siloxane copolymer blocked with trimethylsiloxy groups at both ends, Methyl hydrogen siloxane / diphenyl siloxane / dimethyl silane blocked with trimethylsiloxy groups at both ends Hexane copolymer, both terminals dimethyl siloxane groups at methylhydrogensiloxane-dimethylsiloxane-diphenylsiloxane copolymers, (CH _{3) 2} HSiO _1/2 units and (CH _{3) 3} SiO
Copolymer consisting of _1/2 unit and SiO _4/2 unit, (CH ₃ ) ₂
A copolymer consisting of HSiO _1/2 units and SiO _4/2 units,
(CH ₃ ) ₂ HSiO _1/2 unit, SiO _4/2 unit and (C ₆ H ₅ ) ₂
Examples thereof include copolymers composed of HSiO _1/2 units.

The amount of the organohydrogenpolysiloxane blended is preferably 0.1 to 50 parts by weight, more preferably 0.3 to 20 parts by weight, based on 100 parts by weight of the organopolysiloxane of component (1). Further, the organohydrogenpolysiloxane of the component (2) has an amount of the hydrogen atom (SiH group) bonded to the silicon atom in the component (2) with respect to 1 mol of the alkenyl group bonded to the silicon atom of the component (1). Is 0.5-
It can also be blended in an amount of 5 mol, particularly about 0.8 to 2.5 mol.

As the addition reaction catalyst of the component (3), platinum black, secondary platinum chloride, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, a complex of chloroplatinic acid and olefins, and platinum bis Examples thereof include platinum group catalysts such as acetoacetate, palladium group catalysts and rhodium group catalysts. The addition amount of the addition reaction catalyst can be a catalytic amount, and is usually 0.5 to 1000 p as the platinum group metal.
pm, especially about 1 to 500 ppm is preferable. The addition reaction-curable organopolysiloxane composition has the above-mentioned (1), (2),
(3) Prepared by the component.

On the other hand, the organopolysiloxane composition having an average of two or more alkenyl groups in one molecule of the component (i) of the organic peroxide-curable organopolysiloxane composition is the same as the component (1). Things can be used. As the organic peroxide as the component (ii), known ones can be used. For example, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dicumyl peroxide, 2,5-dimethyl-bis (2,4- t-Butylperoxy) hexane, di-t-butylperoxide, t-butylperbenzoate, 1,1-bis (t-
Examples thereof include butylperoxy) 3,3,5-trimethylsilohexane and 1,6-bis (t-butylperoxycarboxy) hexane.

The compounding amount of the organic peroxide is a catalytic amount,
Usually, it can be 0.01 to 10 parts by weight with respect to 100 parts by weight of the component (i) organopolysiloxane. The organic peroxide-curable organopolysiloxane composition,
It is prepared from the components (i) and (ii).

In the present invention, the thermosetting organopolysiloxane composition as the component (A) contains, as the component (B), a fine filler made of an unexpanded organic resin expandable by heating or an already expanded organic resin. Add a small hollow filler. This filler functions to reduce the specific gravity like sponge rubber by providing a gas portion in the cured rubber.

The filler is vinylidene chloride, acrylonitrile, methacrylonitrile, acrylic ester,
It is preferably formed by a polymer of a monomer selected from methacrylic acid ester or a copolymer of two or more kinds of the above monomers. In this case, the fine filler made of unexpanded organic resin is one in which a volatile substance or a low boiling point substance is included in an organic resin shell. In the present invention, the unexpanded fine filler may be expanded at the same time as it is heated and cured to form a hollow filler, or a preexpanded hollow filler may be blended. When this hollow filler is blended, in order to improve the strength of the hollow filler, it is possible to blend one in which an inorganic filler or the like is attached to the surface.

The above-mentioned filler has a true specific gravity of 0.01 to 0.5 as a hollow filler in its expanded state in order to impart functions such as sufficient reduction of specific gravity and reduction of thermal conductivity in the silicone foam 1. , Preferably 0.01 to 0.3. This is because if it is less than 0.01, compounding and handling will be difficult, and the hollow filler will have insufficient pressure resistance and will be destroyed during molding, making it impossible to reduce the weight. . On the contrary, if the true specific gravity exceeds 0.5, the specific gravity will not be sufficiently reduced.

The fine hollow filler has an average particle diameter of 10 to 200 μm after expansion, preferably 10 to 150 μm.
It is good to have a size of m. This is because when the diameter is greater than 200 μm, the hollow filler is destroyed by the pressure during molding to increase the specific gravity, the space 2 cannot be formed, and the durability is reduced. The average particle size of the micro hollow filler can be obtained as, for example, a weight average value (or median diameter) by a particle size distribution measuring device by a laser diffraction method. The compounding amount is 0.1 to 3 with respect to 100 parts by weight of the organopolysiloxane composition.
The amount is 0 parts by weight, preferably 0.2 to 20 parts by weight, and it may be added so that the volume ratio is 10 to 80%. This is 10
If it is less than%, the specific gravity and the thermal conductivity are not sufficiently reduced, and the open-cell type silicone foam 1 cannot be obtained. On the other hand, when it exceeds 80%, not only molding and compounding become difficult, but also a brittle molded product lacking rubber elasticity may be obtained.

In the present invention, one type or two or more types of the polyhydric alcohol as the component (C) which is an open-cell foaming agent and derivatives thereof are blended. The component (C) functions to improve the compression set. The polyhydric alcohol is composed of a monomer having at least two alcoholic hydroxyl groups in the molecule, or an oligomer or polymer thereof. For example, glycerin, ethylene glycol, propylene glycol, pentaerythritol, glycerin-α-monochlorohydrin and the like, and oligomers or polymers thereof such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polyglycerin, etc. can give. In addition,
These oligomers or polymers have a degree of polymerization of 2
-10, especially about 2-5 is most suitable from the viewpoint of low compression set.

Examples of the polyhydric alcohol derivative include partially etherified products such as ethylene glycol monoethyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether and dipropylene glycol monoethyl ether, glycerin monoacetate,
Examples thereof include partial esterified products such as glycerin diacetate and ethylene glycol monoacetate, and partially silylated products such as monomers having at least one residual alcoholic hydroxyl group in the molecule or oligomers or polymers thereof. The degree of polymerization of the derivative oligomer or polymer is preferably from 2 to 10, and particularly preferably from 2 to 5 for the same reason.

The amount of the polyhydric alcohol or derivative as the component (C) is 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight, based on 100 parts by weight of the organopolysiloxane composition. This is because when it is too small, the effect of imparting the low compression set property is not sufficiently exerted, and when it is too large, the effect on the rubber material is large, and, for example, rubber hardness and strength (tensile strength and tear strength). ) Is lowered or the curability is deteriorated.

The silicone rubber material may be blended with a thixotropic (thixotropic) imparting agent. The thixotropic agent is not particularly limited as long as it can suppress the fluidity of the material and impart thixotropy to the composition, but in general, it is fumes as a solid material. Examples of the silica include fumed silica, fumed titanium oxide, and carbon. These may be used as they are, or may be surface-treated with an organic silicon compound such as hexamethylsilazane, trimethylchlorosilane, polymethylsiloxane and the like. Further, as the liquid material at room temperature, any material may be used so long as it is incompatible with the composition, but a polyethylene having an average degree of polymerization of 20 or more, such as polyethylene oxide, polypropylene oxide, or polyethylene glycol, may be used. Ethers, block polymers of these and siloxanes, copolymers of dimethylsiloxane and diphenylsiloxane, etc. are mainly used.

The thixotropic agent may be used alone or in combination of two or more.
The amount is preferably 0.01 to 30 parts by weight, more preferably 0.03 to 20 parts by weight, based on 100 parts by weight of the component (A) organopolysiloxane. This is because when the amount is less than 0.01 parts by weight, sufficient thixotropic properties may not be obtained.
On the other hand, when it is more than 30 parts by weight, the moldability and the rubber physical properties may be adversely affected.

In order to improve the mechanical strength, heat resistance and flame retardancy of the molded product, various fillers are added to the silicone rubber material in order to improve the mechanical strength, heat resistance and flame retardancy of the molded product. be able to. Examples of the filler include reinforcing fillers such as precipitated silica and pyrogenic silica, non-reinforcing fillers such as ground quartz, diatomaceous earth, asbestos, aminosilicic acid, iron oxide, zinc oxide, calcium carbonate, magnesium carbonate and cerium oxide. Examples of the filler include the filler as it is and the one surface-treated with an organic silicon compound such as hexamethylsilazane, trimethylchlorosilane or polymethylsiloxane.

Furthermore, in addition to the above-mentioned essential components, the silicone rubber material also includes a flame retardant and a fire resistance improver as optional components.
Various additives such as sensitizers, colorants, heat resistance improvers and reducing agents, reaction control agents such as ethynylcyclohexanol, release agents,
Alternatively, a filler dispersant or the like can be added. It is preferable that various kinds of alkoxysilane, carbon functional silane, silanol group-containing low-molecular-weight siloxane and the like used as the dispersant for the filler be kept to a minimum amount so as not to impair the effects of the present invention.

The silicone rubber material is prepared by uniformly mixing the above components with a rubber kneader such as a two-roll roll, a Banbury mixer, a kneader, etc., and adding a heat treatment if necessary. In this case, for example, a part or all of the organopolysiloxane of the first component and an inorganic filler such as silica are mixed in advance with a surface treatment agent as required to prepare a base compound, and the remaining first component is added to the base compound. Organopolysiloxane, second component organohydrogenpolysiloxane, third component addition reaction catalyst, hollow filler, polyhydric alcohol, and other optional components may be mixed.

When the silicone foam 1 according to the present invention is produced, a silicone rubber material comprising the above components is filled in a mold, and heat of 120 to 220 ° C. is applied for 5 minutes to 1 hour to obtain (A). 100 parts by weight of the thermosetting organopolysiloxane composition as a component are cured, and (C) a fine filler made of an unexpanded organic resin or a fine hollow filler made of an expanded organic resin, which is expandable by heat of the component (B), The open cell type silicone foam 1 can be molded by making holes in one or more of the component polyhydric alcohol and its derivative. At this time, care should be taken that pressure does not act as much as possible. This is to prevent the hollow filler from being destroyed by pressure during molding.

The compression set characteristic of the silicone foam 1 is 3
-8%, and the compression set characteristic of each support sheet 10 is 4-11%. This allows
Insulation foam silicone sheet has compression set characteristics of 5-11
Within the range of%. Each support sheet 10 is molded to a thickness of 5 to 50% of the thickness of the silicone foam 1. If the thickness is less than 5%, it is difficult to obtain sufficient rigidity. On the contrary, if the thickness exceeds 50%, the load effect of each support sheet 10 is large and the low load of the silicone foam 1 is exerted. Is lost. The thickness of the pair of support sheets 10 may be 5 to 50% of the thickness of the silicone foam 1.

According to the above construction, since a manufacturing method which does not generate gas is adopted, it is not necessary to strictly control the temperature at the time of molding, and it is not necessary to consider any adverse effects on the human body or the environment. Therefore, it is possible to very effectively solve the problem that the load resistance varies depending on the part of the silicone foam 1 and the use range tolerance becomes narrow. Further, since the silicone foam 1 is a continuous foam type and air flows between the silicone foam 1 and the outside where the support sheet 10 does not exist, a change in volume can be expected greatly. As a result, the load does not increase, so that it can be safely used for electric / electronic devices having low mechanical strength.

Further, since the continuous foaming space 2 allows the air to flow between the outside and the compression set, the compression set and the sufficient reaction force peculiar to the silicone rubber can be generated even under a low load. Will be possible. Therefore, since it does not need to be used in an over-compressed state, it is possible to greatly contribute to the thinning of electric and electronic devices. Further, since the support sheet 10 supports the silicone foam 1 as a support, it is possible to expect a great improvement in handleability. Furthermore,
Since it is possible to control the size of the foaming holes (single foam to continuous foam) to 10 to 200 μm, it is possible to set the compression range used to 10 to 50% of the conventional range from 10 to 25%,
It can be used in a wide range.

[0040]

EXAMPLE An example of the insulating and foamed silicone sheet according to the present invention will be described below with reference to FIG. First,
(A) 100 parts by weight of a thermosetting organopolysiloxane composition, (B) 3 parts by weight of a hollow microfiller made of an expanded organic resin,
And (C) 4 parts by weight of the open-cell foaming agent were kneaded as a silicone rubber material. The silicone rubber material thus obtained was filled in a mold, and heat of 120 ° C. was applied for 10 minutes under a pressure of 1 kg / cm ² to mold an open-cell type silicone foam, and then, on both front and back surfaces of the silicone foam. The support sheets were stacked and adhered. The thickness of the pair of support sheets was 10% of the thickness of the silicone foam.

A compression test was carried out on the insulating foamed silicone sheet according to the present invention and the conventional insulating foamed silicone sheet, and the results shown in FIG. 3 were obtained. The results shown in FIG. 3 are summarized in Table 1.

[0042]

[Table 1]

[0043]

As described above, according to the present invention, it is possible to widen the use range tolerance and to use it for electric and electronic equipment having low mechanical strength, and to expect sufficient compression performance. There is an effect that the handleability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an embodiment of an insulating foam silicone sheet according to the present invention.

FIG. 2 is a cross-sectional explanatory view showing a silicone foam in an embodiment of an insulating foam silicone sheet according to the present invention.

FIG. 3 is a graph showing an example of an insulating foam silicone sheet according to the present invention.

FIG. 4 is an explanatory cross-sectional view showing a conventional silicone foam.

[Explanation of symbols]

1 Silicone foam 2 foam spaces 10 Support Sheet

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F074 AA90 AD04 AG20 BA91 BB02                       BB09 CB62 CC04Y CC06Y                       CC32Y CD02 DA24 DA33                 4F100 AH10B AK01B AK52A AK52B                       AK52C AN00A AN00B AN00C                       BA02 BA03 BA07 BA10A                       BA10C BA25A BA25C DE01B                       DE04B DJ01B GB43 JA02B                       JA20A JA20B JA20C JG04A                       JG04C YY00A YY00B YY00C                 5G305 AA07 AB15 BA18 BA25 CA26                       DA11

Claims (4)

[Claims] 1. An insulating foamed silicone sheet comprising an insulating silicone foam and a support sheet provided on at least one surface of the silicone foam, wherein the silicone foam is a thermosetting organopolysiloxane. 100 parts by weight of the composition, 0.1 to 30 parts by weight of a heat-expandable unexpanded organic resin fine filler or expanded organic resin fine hollow filler, and one or more polyhydric alcohols and derivatives thereof 0 An insulating foamed silicone sheet characterized by being formed using a silicone rubber material containing 0.5 to 50 parts by weight, and the support sheet being an insulating silicone rubber sheet. 2. The insulating foamed silicone sheet according to claim 1, wherein the fine hollow filler contained in the silicone rubber material has an average particle size of 10 to 200 μm. 3. The insulating foamed silicone sheet according to claim 1, wherein the silicone foam has a compression set characteristic of 3 to 8% and the support sheet has a compression set characteristic of 4 to 11%. 4. The thickness of the support sheet is 5 to 50% of the thickness of the silicone foam.
The insulating foamed silicone sheet according to 2 or 3.