JP2003118040A - Composite for impact mitigation - Google Patents

Abstract

(57) [Problem] To provide an impact-mitigating complex which does not have a sticky feeling on its surface and is hardly stained, and which does not bleed oil or the like onto its surface and does not stain its contact partner. SOLUTION: A high hardness silicone rubber coating layer having a hardness of 20 to 90 is provided on the surface of a low hardness silicone rubber layer having a hardness of 15 (durometer unit) or less by adhesion or close contact. It is desirable that the difference in hardness between the two layers is 20 or more. (A1) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to silicon atoms, and (a2) a penetration degree of 5 to 50.
(Mm / min.) Polyorganosiloxane,
(B) a polyorganohydrogensiloxane having at least two hydrogen atoms bonded to silicon atoms;
It can be a cured product of a thermosetting silicone rubber composition containing (c) a silica-based reinforcing filler and (d) a platinum-based catalyst as essential components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorbing composite, and more particularly, it has excellent vibration damping properties and shock absorbing and relaxing properties, and has no sticky feeling on the surface, and bleeding of oil or the like onto the surface. The present invention relates to a composite body which is useful as a member for cushioning human body.

[0002]

2. Description of the Related Art Conventionally, as a shock absorber having excellent soundproofing, vibrationproofing and shock absorption, both sides of a silicone gel layer have been
A composite is known in which stretchable knitted fabrics are superposed so that a silicone gel layer is impregnated (Japanese Patent Publication No. 6-011).
533).

In Japanese Patent Laid-Open No. 6-011533, silicone gel or free silicone oil is used as a shock absorber having flexibility and elasticity used in artificial breasts, pads, knee pads, back pain pads and the like. A laminated body is described in which a coating film in which a silicone rubber having a hardness higher than that of a blended low-hardness silicone rubber and a woven fabric are integrated is laminated, and JP-A-62-189463 (Patent Registration No. 2756557). No.) describes a cut end protection cushioning material for a prosthesis in which a synthetic resin sealed bag is filled with silicone gel.

Further, Japanese Patent Publication No. 7-504937 (Patent Registration No. 2802167) discloses an addition reaction curable low-hardness silicone rubber having a phenyl group (hardness 5 to 55 durometer) as a shock absorber for limbs. A soft tack-reinforced polysiloxane elastomer based on units) is described.

[0005]

However, these conventional shock absorbing / relaxing members have the following problems. That is, in a shock absorbing member having a silicone gel, since the silicone gel has high adhesiveness, a tackiness or a sticky feeling occurs on the surface,
It was easy to get dirty by adsorbing dust in the air. And, in order to prevent such stickiness of the surface, in the member in which the silicone gel is filled in the bag made of synthetic resin, not only the material of the bag may harm human tissues,
The bag was easy to tear, and the silicone gel sealed inside might flow out.

Further, in the shock absorbing member having a low hardness silicone rubber, since a low molecular weight free oil (dimethyl silicone oil etc.) is blended, this free oil leaks out of the system with time (bleed). Then
As a result, there are problems that the contact partner is soiled, the shape is reduced, the hardness is increased, and the feeling of flexibility and elasticity is changed.

The present invention has been made in order to solve these problems and is excellent in shock absorbing / relaxing property, has no sticky feeling on the surface and is not easily soiled, and has no bleeding of oil or the like on the surface. It is an object of the present invention to provide a shock absorbing composite that does not stain a contact partner.

[0008]

According to a first aspect of the present invention, there is provided a shock-absorbing composite body having a hardness of 15 (durometer unit; the same applies hereinafter) on a surface of a low hardness silicone rubber layer. A coating layer made of high hardness silicone rubber having a hardness of 20 to 90 (durometer unit) is adhered or adhered to the coating layer.

In the shock absorbing composite of the present invention, as described in claim 2, it is desirable that the low hardness silicone rubber and the high hardness silicone rubber have a difference in hardness of 20 or more. . Further, as described in claim 3, it is desirable that the thickness of the coating layer made of high hardness silicone rubber is 0.005 to 2 mm.

Further, in the present invention, as described in claim 4, a low hardness silicone rubber is used, and (a1) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom, (A2) a polyorganosiloxane having a penetration of 5 to 50 (mm / min.), (B) a polyorganohydrogensiloxane having at least two hydrogen atoms bonded to silicon atoms, and (c) a silica-based reinforcement. It can be a cured product of a thermosetting silicone rubber composition, which comprises a conductive filler and (d) a platinum-based catalyst as essential components. Further, as described in claim 5, the low hardness silicone rubber comprises (a1) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to silicon atoms, and (a2) a penetration degree of 5 ~
50 (mm / min.) Polyorganosiloxane,
It can be a cured product of a thermosetting silicone rubber composition containing (c) a silica-based reinforcing filler and (e) an organic peroxide as essential components.

Furthermore, according to the present invention, claim 6
As described in, a high-hardness silicone rubber is prepared by using (a) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to silicon atoms and (b) at least 2 hydrogen atoms bonded to silicon atoms. It can be a cured product of a thermosetting silicone rubber composition containing, as essential components, a polyorganohydrogensiloxane having a unit, (c) a silica-based reinforcing filler, and (d) a platinum-based catalyst. Further, as described in claim 7, a high hardness silicone rubber is used, (a) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to silicon atoms, and (c) a silica-based reinforcing filler. And a thermosetting silicone rubber composition containing (e) an organic peroxide as essential components.

In the impact-damping composite of the present invention, the hardness of the low hardness silicone rubber layer having a hardness of 15 or less tested and measured by the durometer has a hardness of 20 to 90 similarly tested and measured by the durometer. The coating layer made of high-hardness silicone rubber is adhered or adhered so that the surface does not feel sticky (sticky or tacky) and does not easily get dirty, and it has a soft and elastic good touch. Have. In addition, since the surface coating layer and the inside are made of the same material, they can follow each other and can be restored even when deformed by an external force. Furthermore, since it does not cause oil bleeding, it has various advantages that it does not stain the contacted person, does not become smaller in shape over time, does not become hard, and is harmless to the human body and affects the hormone system of the living body. Never.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

FIGS. 1 (a) and 1 (b) are a horizontal cross-sectional view and a vertical cross-sectional view, respectively, showing the structure of a shock absorbing composite body according to an embodiment of the present invention. In the figure, reference numeral 1 indicates a low hardness silicone rubber layer, on the surface of which 0.00
A coating layer 2 made of high-hardness silicone rubber having a thickness of 5 to 2 mm is provided so as to adhere or adhere.

In the shock absorbing composite body of the embodiment, the low hardness silicone rubber constituting the main body is made of JlS K624.
The hardness measured by a durometer (type E) defined by 9 has a value of 15 or less, more preferably 0 to 8. Further, the high hardness silicone rubber constituting the coating layer has a hardness of 20 to 90, and more preferably 50 to 70, as measured by a durometer (type A) similarly specified in JIS K6249. Such low hardness silicone rubber and high hardness silicone rubber are
It is desirable to use them in combination so as to have the above hardness differences.

If the hardness of the low-hardness silicone rubber exceeds 15, it is not possible to obtain a composite which is flexible and has sufficient impact absorption / relaxation. When the hardness of the high hardness silicone rubber is less than 20, the surface has tackiness and tackiness, and when it exceeds 90, the silicone rubber itself becomes brittle, and when it is molded or subjected to an external impact. The surface is cracked. In addition, the surface becomes too hard, resulting in poor soft and elastic feeling.

As the low-hardness silicone rubber and the high-hardness silicone rubber, any type can be used as long as it satisfies the above-mentioned characteristics (hardness). Curable thermosetting silicone rubber composition (hereinafter referred to as addition type silicone rubber)
And a cured product of a peroxide curable thermosetting silicone rubber composition (hereinafter referred to as peroxide type silicone rubber) using an organic peroxide. . Then, both low hardness silicone rubber and high hardness silicone rubber are cured products of addition type silicone rubber, both low hardness silicone rubber and high hardness silicone rubber are cured products of peroxide type silicone rubber, and low hardness silicone rubber is addition type silicone rubber. High hardness silicone rubber is a cured product of peroxide type silicone rubber, or low hardness silicone rubber is a cured product of peroxide type silicone rubber and high hardness silicone rubber is a cured product of addition type silicone rubber. It can be used in combination.

The addition reaction-curable thermosetting silicone rubber composition (addition-type silicone rubber) used for the low-hardness silicone rubber includes, for example, at least (a1) an aliphatic unsaturated hydrocarbon group bonded to a silicon atom. Two polyorganosiloxanes and (a2) penetration of 5-5
0 (mm / min.) Polyorganosiloxane,
(B) a polyorganohydrogensiloxane having at least two hydrogen atoms bonded to silicon atoms,
Examples thereof include a composition containing (c) a silica-based reinforcing filler and (d) a platinum-based catalyst as essential components. In addition,
Penetration is a value of penetration measured by a penetration tester of JIS K2808.

The addition type silicone rubber used for the high hardness silicone rubber is, for example, (a) at least 2 aliphatic unsaturated hydrocarbon groups bonded to silicon atoms.
Essential polyorganosiloxane, (b) polyorganohydrogensiloxane having at least two hydrogen atoms bonded to silicon atoms, (c) silica-based reinforcing filler, and (d) platinum-based catalyst. The composition can be mentioned.

Here, each of the component (a1) and the component (a) is a main component of the composition, and specifically, the general formula: R ¹ _a R ² _b SiO _{[4- (a + b)] / 2} The polyorganosiloxane represented by (1) can be mentioned.

In the formula (1), R ¹ has 2 to 10 carbon atoms.
Preferably, it represents a monovalent aliphatic unsaturated hydrocarbon group of 2 to 6, and specifically, a vinyl group, an allyl group, a propenyl group,
Alkenyl groups such as an isopropenyl group, a butenyl group and an isobutenyl group are suitable. It is particularly preferably a vinyl group.

R ² has 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms.
Represents a substituted or unsubstituted monovalent hydrocarbon group. However,
The above-mentioned aliphatic unsaturated hydrocarbon group is excluded.

Specific examples of R ² include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, cyclohexyl group and octyl group. An aryl group such as a phenyl group or a tolyl group; an aralkyl group such as a benzyl group or a phenylethyl group; and some or all of the hydrogen atoms of these groups are a halogen atom such as fluorine, chlorine or bromine, or a cyano group. Substituted ones such as chloromethyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group and the like can be mentioned. Of these, a methyl group, a phenyl group and a trifluoropropyl group are particularly preferable.

Further, a and b in the equation (1) represent numbers satisfying the relationships of 0 <a ≦ 1, 1 <b <3, 1 <a + b <3, respectively. Preferably, 0.0001≤a≤0.
5, 1.8 ≦ b ≦ 2.2, 1.8 ≦ a + b ≦ 2.25.

In the polyorganosiloxane represented by the formula (1), it is necessary that two or more of the above aliphatic unsaturated hydrocarbon groups are bonded to silicon atoms in one molecule. This aliphatic unsaturated hydrocarbon group may be bonded to a silicon atom at the terminal of the molecular chain, or may be bonded to any of the silicon atoms in the middle of the molecular chain, or may be bonded to both. good.

The polyorganosiloxane may have a linear, branched or cyclic molecular skeleton, but it has diorganosiloxane as a repeating unit in the main chain portion, and the molecular chain end is trivalent. Those which are organosiloxanes are common. In addition, the degree of polymerization (Si in the molecule
Number of atoms) is 10 to 20000, preferably 100 to 1
It may be about 5,000.

The component (a2) is a component to be blended in order to adjust the low hardness silicone rubber to a desired hardness (15 or less). Specifically, the general formula: R ³ _c R ⁴ _d SiO _{4 [4] -(C + d)] / 2} ... (2) Polyorganosiloxane (silicone raw rubber) can be mentioned.

In the formula (2), R ³ has 10 carbon atoms.
In the following, a monovalent aliphatic unsaturated hydrocarbon group which is preferably 1 is represented, and specifically, an alkenyl group such as a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group and an isobutenyl group is preferable. To do. It is particularly preferably a vinyl group. R ⁴ is the same as R ² in the formula (1) representing the component (a1) and the component (a) and is substituted or non-substituted with a carbon number of 1 to 12, preferably 1 to 8 excluding an aliphatic unsaturated hydrocarbon group. It represents a substituted monovalent hydrocarbon group.

Here, c and d are 0≤c≤1, respectively.
A polyorganosiloxane having a number satisfying the relationship of 1 <d ≦ 3, 1 <c + d <3, but having a value of c of 0 and having no aliphatic unsaturated hydrocarbon group bonded to a silicon atom is used. Is more desirable. The polyorganosiloxane may have a linear, branched, or cyclic molecular skeleton, but has diorganosiloxane as a repeating unit in the main chain portion, and the molecular chain end is triorganosiloxane. Some are common, and 5 to 50
It has a degree of polymerization adjusted to have a penetration of (mm / min.).

The component (b) is a component which serves as a crosslinking agent for the above-mentioned component (a1) or component (a), and specifically, it has the general formula: R ⁵ _e H _f SiO _{[4- (e + f)] ] / 2} ... (3) The polyorganohydrogen siloxane shown by these can be mentioned.

In the formula (3), R ⁵ has 1 to 1 carbon atoms.
2 preferably represents 1 to 8 substituted or unsubstituted monovalent hydrocarbon group. However, an aliphatic unsaturated hydrocarbon group is excluded.

Specific examples of R ⁵ include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, cyclohexyl group and octyl group; An aryl group such as a phenyl group and a tolyl group; an aralkyl group such as a benzyl group and a phenylethyl group; and some or all of the hydrogen atoms of these groups are substituted with a halogen atom such as fluorine, chlorine or bromine, or a cyano group. Examples thereof include chloromethyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group and the like. Among these, those having 1 to 4 carbon atoms are preferable, and an alkyl group is preferable from the viewpoint of ease of synthesis and cost. A methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a tert-butyl group are preferable, and a methyl group is particularly preferable.

Further, e and f in the equation (3) are 0.8≤e≤2.2 and 0.002≤f≤1,0.8 <e, respectively.
It represents a number that satisfies the relationship of + f <3. Preferably, 1 ≦
It is a number that satisfies the relationship of e ≦ 2.2, 0.01 ≦ f ≦ 1, 1.8 ≦ e + f ≦ 2.5.

The polyorganohydrogensiloxane may have a linear, branched or cyclic molecular skeleton, and contains a diorganohydrogensiloxane unit and a SiO ₂ unit, and is appropriately triorganosiloxane. It may be a resinous material having a three-dimensional network structure containing units or diorganosiloxane units.

In this polyorganohydrogensiloxane, the SiH group in which a hydrogen atom is bonded to a silicon atom is
At least two, preferably three or more are formed in one molecule. In this case, the H atom may be bonded to the silicon atom at the terminal of the molecular chain, may be bonded to any of the silicon atoms in the middle of the molecular chain, or may be bonded to both. The degree of polymerization (the number of Si atoms in the molecule) is
It is preferably from 3 to 400, especially from 4 to 300.

The silica-based reinforcing filler as the component (c) is a filler blended to enhance the strength characteristics of the silicone rubber layer formed. Examples include fumed silica, precipitated silica, fused silica and the like, which are generally blended with silicone rubber, and those having a particle diameter of 20 μm or less are particularly preferable.

The component (c) may be surface-treated with organosilane, organosiloxane, organosilazane or the like in advance, or may be reacted in-process with the above treating agent. good.

The platinum-based catalyst of the component (d) has the above-mentioned (a)
A catalyst for initiating an addition reaction between component 1) or component (a) and component (b), such as platinum or primary chloride
Platinum, chloroplatinic acid, or a platinum group metal compound such as a vinyl siloxane complex thereof or an alcohol-modified solution thereof; a rhodium compound, a palladium compound, or the like can be used.

The addition reaction-curable thermosetting silicone rubber composition essentially contains the above-mentioned components (a1) or (a) to (d), but further includes an acetylene compound, a phosphorus compound, a nitrile compound, and a carboxylate. Well-known reaction control agents such as tin compounds, tin compounds, mercury compounds, and sulfur compounds may be blended in appropriate amounts.

In such a silicone rubber composition, the mixing ratio of the component (a1) or the component (a) and the component (b) is the same as that of the aliphatic unsaturated hydrocarbon group of the component (a1) or the component (a). The amount is adjusted to a molar ratio of 1:10 to 10: 1, and more preferably 1: 3 to 3: 1 with the hydrogen atom of the component (b).

On the other hand, if the blending ratio of the component (c) is too large, the viscosity of the silicone rubber composition at the time of uncured remarkably increases, and the workability at the time of molding deteriorates. On the contrary, if it is too small, it is formed. The strength characteristics of the silicone rubber layer are not sufficient. Therefore, the blending ratio of the component (c) is preferably 5 to 200 parts by weight with respect to 100 parts by weight of the component (a1) or the component (a).

Further, the blending amount of the component (d) is (a1)
0.1 to 1 in terms of platinum for the component or component (a)
The amount may be 000 ppm, and more preferably 1 to 500 ppm.

Examples of the peroxide curable thermosetting silicone rubber composition (peroxide type silicone rubber) used for the low hardness silicone rubber include (a1) an aliphatic unsaturated hydrocarbon bonded to a silicon atom. A polyorganosiloxane having at least two groups and (a2) a penetration degree of 5 to 5 having no unsaturated hydrocarbon group bonded to a silicon atom.
0 (mm / min.) Polyorganosiloxane,
Examples thereof include (c) a silica-based reinforcing filler, and (e) a composition containing an organic peroxide as an essential component.

Examples of the peroxide type silicone rubber used for the high hardness silicone rubber include (a) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom, and (c) ) A silica-based reinforcing filler, and (e) a composition containing an organic peroxide as an essential component.

Here, the component (a1), the component (a2),
Examples of the component (a) and the component (c) are the same as those described above for the addition-type silicone rubber. The organic peroxide of the component (e) is (a)
Component 1) or component (a) that serves as a cross-linking agent, and is benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, ditertiary butyl peroxide, dicumyl peroxide, 2,5-dimethyl-
2,5-di (tert-butylperoxy) hexane and the like can be mentioned.

This peroxide type silicone rubber has
It is prepared by uniformly kneading the component (c) with the component (1) and the component (a2) or the component (a), and then uniformly mixing the organic peroxide as the component (e). The compounding amount of the organic peroxide is set to 0.1 to 5 parts by weight with respect to 100 parts by weight of the component (a1) or the component (a).

The low-hardness silicone rubber and the high-hardness silicone rubber used in the present invention can be obtained by heating and curing a composition obtained by uniformly mixing the above-mentioned respective components. Further, non-reinforcing fillers such as quartz powder, diatomaceous earth, calcium carbonate powder, alumina powder; conductivity imparting agents such as carbon black, various metal powders, various metal oxide powders; pigments such as red iron oxide and titanium oxide. A known heat-resistant agent, flame retardant, adhesion-imparting agent or the like may be added in an appropriate amount.

In the present invention, in order to mold a composite in which a high hardness silicone rubber coating layer is formed on the surface of a low hardness silicone rubber layer, the method shown below is applied according to the state of the silicone rubber composition before curing. Can be taken.

That is, when the silicone rubber composition before curing is in a compound form (millable type), each method of press molding, transfer molding or injection molding can be adopted, and when it is liquid,
It can be molded by injection molding. Further, a high hardness silicone rubber coating layer can be provided on the surface of the low hardness silicone rubber layer by coating. There are two types of coating methods, dip coating and spray coating. The uncrosslinked liquid silicone rubber composition is used as it is, or with toluene, xylene,
It can be used by appropriately diluting it with an organic solvent such as hexane or alcohol or a low molecular weight siloxane.

The above-mentioned addition reaction-curable thermosetting silicone rubber composition and peroxide-curable silicone rubber composition, when uncured products are laminated by a combination of curing mechanisms, are cured into a cured product. When an uncured product is applied, the resulting composite may have poor adhesion. As an example thereof, there is a case in which an uncured product of an addition type high hardness silicone rubber is laminated or applied to a cured product of an addition type low hardness silicone rubber. In that case, the adhesive strength of the coating layer can be increased by applying an adhesive primer to the interface between the low hardness silicone rubber layer and the high hardness silicone rubber coating layer.

The method for producing the impact-damping composite of the present invention will be described in detail below in accordance with the cured state of the low-hardness silicone rubber layer and the high-hardness silicone rubber coating layer.

[Lamination of uncured low-hardness rubber layer and uncured high-hardness rubber coating layer] (1) Uncrosslinked silicone rubber composition adjusted so that the hardness after curing is about 20 (compound Silicone rubber and a cross-linking agent (hardness after curing is 0-8)
To obtain a low hardness silicone rubber compound. next,
A crosslinking agent is added to an uncrosslinked silicone rubber composition (compound-like) having a hardness after curing of 40 to 90 and mixed by a two-roll to dispense into a thickness of 0.5 to 2 mm. Next, the obtained high-hardness silicone rubber compound is attached to the surface of the above-mentioned low-hardness silicone rubber compound and then charged into a mold and heated to cure the silicone rubber.

(2) A silicone raw rubber and a cross-linking agent are added to an uncrosslinked silicone rubber composition (compound form) adjusted to have a hardness after curing of about 20 (hardness after curing is 0 to (Adjusted to 8) Mixing with two rolls and dispensing, this low hardness silicone rubber compound is charged into a mold. Next, the hardness after curing is 40 to 90.
A crosslinking agent is added to the uncrosslinked silicone rubber composition (liquid), mixed and defoamed, and then the liquid silicone rubber is poured into the mold and heated to cure the silicone rubber.

(3) A cross-linking agent is added to an uncrosslinked silicone rubber composition (compounded form) adjusted to have a hardness after curing of 40 to 90 and mixed by a two-roll mill to 0.5.
After dispensing to a thickness of ˜2 mm, this high hardness silicone rubber compound is charged into a mold. Next, the raw silicone rubber and the crosslinking agent are added to the uncrosslinked silicone rubber composition (liquid) (adjusted so that the hardness after curing is 0 to 8), mixed and defoamed, and then the liquid silicone is obtained. The rubber is poured into the mold and heated to cure the silicone rubber.

In the molding methods (1) to (3), a combination of a low-hardness silicone rubber and a high-hardness silicone rubber is used, and both are addition reaction-curable or peroxide-curable, low-hardness silicone rubber. It is possible to use an addition reaction curable type, a high hardness silicone rubber is a peroxide curable type, a low hardness silicone rubber is a peroxide curable type, and a high hardness silicone rubber is an addition reaction curable type.

[Lamination of an uncured high hardness rubber coating layer on a cured low hardness rubber layer] (4) An uncrosslinked silicone rubber composition (compounded form) adjusted so that the hardness after curing is about 20 To, silicone raw rubber and a cross-linking agent are added (the hardness after curing is 0 to 8
After mixing and dispensing with a two-roll mill, this low hardness silicone rubber compound is charged into a mold and heated to cure. Then, the obtained low hardness silicone rubber cured product is taken out from the mold. Next, a crosslinking agent is added to an uncrosslinked silicone rubber composition (liquid) having a hardness after curing of 40 to 90 and mixed and defoamed, and the liquid silicone rubber is then applied to the surface of the low hardness silicone rubber cured product. And heat to cure the liquid silicone rubber.

(5) Silicone raw rubber and a crosslinking agent are added to the uncrosslinked silicone rubber composition (liquid) (adjusted so that the hardness after curing is 0 to 8), mixed and defoamed, and then gold Pour into a mold and heat to cure. Then, the obtained low hardness silicone rubber cured product is taken out from the mold. Next, a crosslinking agent is added to an uncrosslinked silicone rubber composition (compounded form) having a hardness after curing of 40 to 90, and mixed by a two-roll to dispense into a thickness of 0.5 to 2 mm. afterwards,
This high-hardness silicone rubber compound is attached to the surface of the aforementioned low-hardness silicone rubber cured product, and then the whole is charged into a mold and heated to cure the high-hardness silicone rubber compound.

[Lamination of a cured high hardness rubber layer and an uncured low hardness rubber layer] (6) An uncrosslinked silicone rubber composition adjusted to have a hardness after curing of 40 to 90 (compound form) ) Is mixed with two rolls, and the mixture is dispensed to a thickness of 0.5 to 2 mm. Then, this is charged into a mold and heated to cure. Then, the obtained hardened silicone rubber cured product is taken out of the mold and placed in another large mold. Next, a raw silicone rubber and a crosslinking agent are added to the uncrosslinked silicone rubber composition (liquid) (adjusted so that the hardness after curing is 0 to 8), mixed and defoamed, and then this liquid silicone rubber is obtained. Is poured into the above-mentioned mold and heated to cure.

(7) A crosslinking agent was added to an uncrosslinked silicone rubber composition (liquid) adjusted to have a hardness after curing of 40 to 90, and after mixing and defoaming, 0.5 was added to a mold. ~ 2 mm
It is poured to the thickness of and cured by heating. Then, the obtained hardened silicone rubber cured product is taken out of the mold and placed in another large mold. Next, a raw silicone rubber and a crosslinking agent are added to the uncrosslinked silicone rubber composition (liquid) (adjusted so that the hardness after curing is 0 to 8), mixed and defoamed, and then this liquid silicone rubber is obtained. Is poured into the above-mentioned mold and heated to cure.

In the molding methods (4) to (7), the low-hardness silicone rubber and the high-hardness silicone rubber are both peroxide-curable, the low-hardness silicone rubber is an addition reaction-curable, and the high-hardness silicone rubber is a peroxide. A curable type and a low-hardness silicone rubber may be used, and a high-hardness silicone rubber may be an addition reaction curable type. A combination of low-hardness silicone rubber and high-hardness silicone rubber of addition reaction curing type cannot be applied because the adhesiveness at the interface between both layers is deteriorated.

The shock absorbing composite of the present invention is a pad for use in artificial breasts for women who have had their breasts removed, bras for breast augmentation, low back pain pads or shoulder pads, and cut end protection cushion materials for artificial legs. Although it can be preferably used for, for example, sports equipment, martial arts equipment, vehicle-related equipment, toys for infants, general household equipment, etc.
It can be applied as a shock absorber used for protection. It can also be applied to soundproofing equipment and antivibration equipment in facilities. Specifically, the buttocks of sports pants, knee pads or non-slip socks, supporters for keeping warm and cold, pads for ski pants, helmets, toilet seat mats, underlay mats for furniture, shoes bottoms, eyeglass pads, car bumpers,
Child seat, air bag, anti-vibration rubber (CD, D
VD, floppy (registered trademark) drive, etc.), pen grip, golf grip, pillow, bicycle saddle, riding saddle, water hammer prevention tube, electric tool grip, door protector, car engine push, keyboard hand rest It can be used for watches, earpicks, lures, tambo printing, emblems, patches, pressure hoses, etc.

Next, specific examples of the present invention will be described. In the following Examples and Comparative Examples, parts represent parts by weight.

Example 1 40 parts of TSE2523U (trade name of GE Toshiba Silicones Co., Ltd .; millable silicone rubber composition, hardness after curing 30), TSE200 (trade name of GE Toshiba Silicones Co., Ltd.); 60 parts of silicone raw rubber having no reactive group to be bonded to silicon atom and TC-8 (trade name of GE Toshiba Silicone Co., Ltd .; 2,5-dimethyl-2,5-di (tertiarybutylperoxy) hexane) 0.5 parts of 50%) was added and mixed to obtain a compound-like silicone rubber composition A. Then, TSE252
7U (trade name of GE Toshiba Silicone Co., Ltd .; millable silicone rubber composition, hardness after curing 70) 10
Silicone rubber composition B (compound form) obtained by adding 0.8 part of TC-8 to 0 part and mixing was dispensed to a thickness of 1 mm. Then, after sticking this on the surface of the above-mentioned silicone rubber composition A, the whole is charged into a mold, and 1
After press molding at 70 ° C. for 10 minutes, post-crosslinking was performed at 200 ° C. for 4 hours to completely cure.

Example 2 TSE2523U 40 parts, TSE200 60 parts and T
0.5 parts of C-8 was added and mixed, and the obtained silicone rubber composition A (compound form) was charged into a mold, and 170
It was pressed and cured at 10 ° C. for 10 minutes. Then, XE15-645 (A) and XE15-6 were formed on the surface of this cured product.
Liquid silicone rubber composition obtained by mixing 45 (B) (addition reaction curable liquid silicone rubber manufactured by GE Toshiba Silicone Co., Ltd.) in a weight ratio of 1: 1 and depressurizing / defoaming. Was coated and heated in a dryer at 150 ° C. for 10 minutes to cure.

Comparative Example 1 TSE3062 (A) and TSE3062 (B) (trade name of GE Toshiba Silicone Co., Ltd .; room temperature curable silicone gel) were mixed at a weight ratio of 1: 1 and depressurized and defoamed. The liquid polyorganosiloxane composition thus obtained was filled in a bag made of vinyl chloride resin, and heated at 50 ° C. for 1 hour to be cured. As a result, a composite in which a silicone gel was filled in a vinyl chloride resin bag was obtained.

Comparative Example 2 After 0.8 parts of TC-8 was added to 100 parts of TSE2523U and mixed, 100 parts of TSE451-1000 (trade name of GE Toshiba Silicone Co., Ltd .; dimethyl silicone oil, viscosity 1000 cP) was further added. The silicone rubber composition C (compound form) obtained in this way was charged into a mold and press-molded at 170 ° C. for 10 minutes, and then 20
Post-crosslinking was performed at 0 ° C. for 4 hours to completely cure.

Next, the surface adhesion of the composites of the low hardness silicone rubber and the high hardness silicone rubber obtained in Examples 1 and 2 and the sample of the cured silicone rubber obtained in Comparative Examples 1 and 2 were measured. In addition to examining the properties, a drop test and a glass contamination test were performed.

In the drop test, each sample piece was dropped on the floor from a height of 2 m, and the extent of breakage and the state of the floor were examined. Moreover, in the glass contamination test, first, the sample piece (silicon gel in Comparative Example 1) was brought into contact with the glass test piece (25 × 80 mm), a load of 50 g was applied, and the sample was left at room temperature for 10 days.
The sample piece was removed from the surface of the glass test piece. Then
The coefficient of dynamic friction of the surface of this glass test piece was measured using Tribogear TYPE14DR (manufactured by HEIDON Shinto Scientific Co., Ltd.). The friction element has a diameter of 15 mm.
A resin body having a thickness of 5 mm and coated with fluororubber on the outer periphery was used, and washed with IPA before measurement. And vertical load 500g, friction speed 100mm / min, moving distance 4
Under the conditions of 0 mm and room temperature of 23 ° C., the dynamic friction coefficient of the portion of the glass test piece with which the sample piece was in contact was measured. The coefficient of dynamic friction of the glass test piece itself was 1.45.

The results of these tests are shown in Table 1.

[Table 1]

The following can be seen from Table 1. That is, the composites obtained in Examples 1 and 2 do not have a tacky or tacky feeling on the surface, and the components contained inside do not migrate to the glass test piece and are contaminated by the contact. In addition, no damage is caused by dropping, and leakage of components does not occur.

[0071]

As is clear from the above description, the shock absorbing composite material of the present invention is excellent in shock absorbing / relaxing property, has no sticky feeling on the surface, is hard to be soiled, and has an oil on the surface. There is no bleed and does not contaminate the contact partner.

Therefore, it is suitable for artificial breasts, pads used for brassieres for breast augmentation, low back pain pads or shoulder pads, cut end protection cushion materials for artificial legs, etc., and also sports equipment, martial arts equipment, vehicle-related equipment, It can be applied as a shock absorbing / mitigating member for toys for infants, general household appliances, etc.

[Brief description of drawings]

FIG. 1 shows a shock absorbing composite body according to an embodiment of the present invention, in which (a) is a horizontal sectional view and (b) is a vertical sectional view.

[Explanation of symbols]

1 ... Low-hardness silicone rubber layer, 2 ... High-hardness silicone rubber coating layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 83/07 C08L 83/07 F16F 7/00 F16F 7/00 B 15/08 15/08 BF term ( reference) 3J048 AA01 AC01 BA03 BB01 BD04 DA06 3J066 AA02 AA05 AA15 AA30 BA01 BB01 BC01 4F100 AA20A AA20B AA20H AK52A AK52B AK52K AN02A AN02B BA02 BA10B BA16 BA26 CA30A CA30B DD31 JB13A JB13B JK11 JK12A JK12B JL06 YY00A YY00B 4J002 CP03X CP04Y CP13W CP14W DA117 DE197 DJ016 FD016

Claims (7)

[Claims] 1. A coating layer made of a high hardness silicone rubber having a hardness of 20 to 90 is adhered or adhered to the surface of a low hardness silicone rubber layer having a hardness of 15 (durometer unit) or less. A shock absorbing composite characterized by: 2. The impact-damping composite body according to claim 1, wherein the low-hardness silicone rubber and the high-hardness silicone rubber have a difference in hardness of 20 or more. 3. The shock absorbing composite body according to claim 1, wherein the coating layer made of the high hardness silicone rubber has a thickness of 0.005 to 2 mm. 4. The low hardness silicone rubber comprises: (a1) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom; and (a2) having a penetration of 5 to 50 (mm / min.), (b) a polyorganohydrogensiloxane having at least two hydrogen atoms bonded to silicon atoms, (c) a silica-based reinforcing filler, and (d) a platinum-based catalyst. The impact-dampening composite according to any one of claims 1 to 3, which is a cured product of a thermosetting silicone rubber composition as a component. 5. The low hardness silicone rubber comprises: (a1) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom; and (a2) having a penetration of 5 to 50 (mm / min.) polyorganosiloxane, (c) silica-based reinforcing filler, and (e) organic peroxide as essential components, a cured product of a thermosetting silicone rubber composition. Item 1
4. The impact-damping composite according to any one of 1 to 3. 6. The high hardness silicone rubber comprises: (a) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to silicon atoms, and (b) at least 2 hydrogen atoms bonded to silicon atoms. A cured product of a thermosetting silicone rubber composition, which comprises a polyorganohydrogen siloxane having a plurality thereof, (c) a silica-based reinforcing filler, and (d) a platinum-based catalyst as essential components. The impact-damping composite body according to any one of 1 to 5. 7. The high hardness silicone rubber comprises: (a) a polyorganosiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to silicon atoms; (c) a silica-based reinforcing filler; and (e) ) A cured product of a thermosetting silicone rubber composition containing an organic peroxide as an essential component.
6. The impact-damping composite body according to any one of items 1 to 5.