JP2906083B2 - Lightweight heat-insulating resin composition - Google Patents

Description

The present invention relates to a lightweight heat-insulating resin composition having excellent adhesiveness, workability, and mechanical properties.

[Conventional technology]

When flying aerospace equipment such as aircraft and rockets, to protect the fuselage from aerodynamic heating and heat around the engine caused by friction between the body of these aerospace equipment and air, etc., and to keep the temperature of each part of the body proper The body is protected by various heat insulating materials. As such a heat insulating material, for example, a sheet heat insulating material in which cork is impregnated with a phenol resin, a micro balloon made of phenol resin in silicone rubber (hereinafter abbreviated as phenol balloon) and / or a micro balloon made of glass (hereinafter, glass) A heat insulator made of a composition in which microballoons such as balloons are mixed is known.

However, the former requires the airframe to be stuck using an adhesive, and thus requires heating equipment such as a pressurizing equipment such as a vacuum bag and an oven for curing the adhesive, and increases the number of work steps. Construction was complicated. In addition, since the thermal conductivity is high, a sufficient heat insulating effect cannot be exerted unless the thickness is made large, so that the weight of the body increases. On the other hand, since the latter composition also requires the use of an adhesive, the workability is similarly poor, and the thickness of the heat insulating material is increased by the adhesive.

Further, US Pat. No. 4,077,921 discloses that a phenol balloon, a glass balloon, glass fiber, bentonishi, an alcohol-based activator, and the like are mixed with an epoxy-modified urethane resin, and an aromatic amine (curing agent) and a solvent are further compounded. A low-density heat controllable composition has been proposed. However, the heat insulating material formed from this resin composition had a tensile elongation of only about 0.5% at most and was poor in flexibility. For this reason, the construction part cannot follow the large deformation at the time of assembling the work body, or a sudden thermal shock such as aerodynamic heating or an impact load when the aerospace equipment separates, cracks from the construction part There was a danger of generation or peeling.

[Problems to be solved by the invention]

An object of the present invention is to provide a lightweight heat-insulating resin composition having excellent adhesiveness and workability that can be applied to an object to be processed such as an aerospace machine body requiring a high degree of heat insulation without using an adhesive. (Hereinafter simply referred to as a resin composition). Another object of the present invention is to provide a flexible light-weight heat-insulating resin composition having excellent mechanical properties that does not cause cracks, peeling, or the like in a construction portion due to large deformation, thermal shock, impact load, and the like.

[Means for solving the problem]

Such an object of the present invention comprises a polyalkylene glycol polymer A having at least two glycidyl groups at the end, an epoxy resin B and an amine compound C, wherein the polyalkylene glycol polymer A and the epoxy resin B
The mixing ratio of the microballoon D made of borosilicate silica and the microballoon E made of phenol resin to the resin component I whose mixing ratio A / B is 25/75 to 75/25 by weight.
Microballoon I whose D / E is 50 / 50-100 / 5.1 by weight
I can be achieved by a resin composition blended such that the mixing ratio I / II is in the range of 25/75 to 75/25 by weight.

In the resin composition of the present invention, the resin component I is a binder for the microballoon II, and at the same time, improves the adhesiveness to an object to be processed made of a non-metal such as a metal or a fiber-reinforced plastic (FRP). Even if no adhesive is used, good adhesiveness is exhibited.

In the resin component I, the polyalkylene glycol polymer A having a glycidyl group at the terminal of the polymer chain imparts adhesiveness and flexibility to the lightweight heat-insulating resin composition, and has a large deformation and thermal shock as described above. In addition, it is possible to reduce the occurrence of cracks and peeling from a construction part due to an impact load or the like. Examples of such a polyalkylene glycol polymer A include, but are not limited to, diglycidyl polyethylene glycol and diglycidyl tetramethylene glycol.

Further, the epoxy resin B in the resin component I improves mechanical properties such as adhesive strength and shape retention at a high temperature such as when the construction part is heated. This epoxy resin B is a reaction product of epichlorohydrin and a polyhydric phenol. Examples of the epoxy resin B include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, triphenylmethane triglycidyl ether, resorcinol diglycidyl ether, triglycidyl-p-aminophenol, diglycidyl aniline,
Tetraglycidylmethylenedianiline, tetraglycidyl-4,4 '-(4-aminophenyl) -p-diisopropylbenzene, tetraglycidyl-4,4'-(4-amino-3,5-dimethylphenyl) -p-diisopropyl Examples include, but are not limited to, benzene, tetraphenolethanetetraglycidyl ether, phenol novolak glycidyl ether, cresol novolak glycidyl ether, bisphenol A novolak glycidyl ether.

The active hydrogen of the amine compound C in the resin component I reacts with the glycidyl group of the polyalkylene glycol polymer A, and enables the resin composition of the present invention to be cured in a low temperature range from room temperature to 60 ° C. . For this reason, when applying the resin composition of the present invention, as in the case of the above-described cork sheet pasting, since pressurizing equipment and heating equipment are not required, the number of steps required for pasting can be reduced, and workability can be reduced. Is improved. In addition, the mechanical properties of the construction part have the same physical properties as when cured at a high temperature. Examples of such an amine compound C include, for example, diethylenetriamine, triethylenetetramine, isophoronediamine, 1,3-bisaminocyclohexane, diethylaminopropylamine, bis (p-aminocyclohexyl) methane, n-aminoethylpiperazine, Aromatic diamines represented by polyamidoamine, diethylenetriamine / diglycidyl ether bisphenol A mixture, and the like can be given, but not limited thereto.

The above-mentioned polyalkylene glycol polymer A and epoxy resin B are mixed such that the mixing ratio A / B is in the range of 25/75 to 75/25 by weight. If the mixing ratio A / B is less than 25/75, the mechanical properties and flexibility at high temperatures deteriorate, making it difficult to follow large deformation during assembly of the work piece, or causing the work surface to suffer thermal shock or impact load. Cracks and peeling are likely to occur. On the other hand, if the mixing ratio A / B exceeds 75/25, the heat resistance deteriorates, and it becomes difficult to suppress the generation of cracks when receiving a sudden thermal shock such as aerodynamic heating.

In the resin composition of the present invention, the microballoon II
Is composed mainly of microballoons (hereinafter abbreviated as silica balloons) D made of borosilicate silica, and microballoons (hereinafter abbreviated as phenol balloons) E made of a phenol resin are used in combination. On the other hand, an excellent heat insulating property for protecting the body from the aerodynamic heating during the flight of the aerospace equipment described above is provided.

Silica balloon D is composed of borosilicate silica as a hollow granular material, has a small loss on heating, and has excellent heat resistance, heat insulation, and shape retention. Imparts a high degree of heat resistance and heat insulation of the resin composition. The shape and physical properties of the silica balloon may be any as long as they can be uniformly mixed in the resin composition and do not impair the mechanical properties, and preferably have a maximum diameter of 125.
μ, minimum diameter 44μ, average particle diameter 70μ ~ 90μ, bulk density 0.14 ~
0.16 g / cm ^3, it is what is true density 0.20~0.30g / cm ^3.

On the other hand, since the phenol balloon E is a hollow granular material, it has a low density and has thermal controllability. That is, when carbonized by aerodynamic heating, hydrocarbons and other gases are generated and reduced in weight, and have the property of absorbing thermal energy by the latent heat. Therefore, it is possible to reduce the weight of the resin composition of the present invention and to impart heat controllability. As a typical example of such a phenol balloon E, a phenol formaldehyde condensate is preferable as a material, and a maximum diameter of 12
0μ, minimum diameter 5μ, average particle diameter 35 ~ 48μ, bulk density 0.10 ~
0.15 g / cm ^3, preferably a true density 0.21~0.35g / cm ^3.

The mixing ratio D / E of the silica balloon D and the phenol balloon E constituting the microballoon II is 50/50 to 10 by weight.
Be in the range of 0/0. When the mixing ratio D / E is less than 50/50, sufficient heat resistance and heat insulation based on silica balloon D cannot be imparted to the resin composition of the present invention, or good shape retention is exhibited. Will not be.

In the present invention, since both the silica balloon D and the phenol balloon E are used, for example, when a surface of a space device such as a satellite launch vehicle is coated with a resin composition containing both of these balloons, In addition, the phenol balloon E absorbs heat and decomposes and evaporates and disappears under the high temperature of the space device during high-speed flight in the atmosphere, and the silica balloon D absorbs heat and melts, forming a glassy coating on the surface of the space device. By forming, the surface of the space device can be sufficiently protected. In addition, the air contained in both of these balloons also exerts heat absorbing and heat insulating effects. Therefore, when only phenol balloon E is used, the balloon disappears due to thermal decomposition and vaporization, and a crack is generated on the surface of the space device. On the other hand, when only silica balloon D is used,
Insufficient heat absorption at high temperature.

As described above, the resin component I and the microballoon II are mixed so that the mixing ratio I / II is in the range of 25/75 to 75/25 by weight to constitute the resin composition of the present invention. .
If the mixing ratio I / II is less than 25/75, the resin composition of the present invention will not exhibit sufficient adhesiveness, workability, and mechanical properties based on the resin component I. On the other hand, the mixing ratio I / II is 75/25
Is exceeded, the microballoon II is added to the resin composition of the present invention.
Therefore, it becomes difficult to sufficiently impart heat insulation.

Furthermore, various reinforcing materials such as whiskers, chopped fibers, beads and the like, fillers, anti-sagging agents such as aerosil and bentonite, and the like can be appropriately added to the resin composition of the present invention according to the use and purpose.

To apply such a resin composition of the present invention, the composition is diluted with a solvent and applied by spraying. In addition, it can be applied by casting or ironing, and can be applied without spray equipment.

Examples of the above-mentioned solvent for dilution include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, butyl acetate, isobutyl acetate, toluene, xylene, methylene dichloride, trichloroethane, n-hexane, cyclohexane, ethylene glycol monomethyl ether and the like. However, the present invention is not limited to these. These solvents can be used alone or as a mixture of at least two types.

The object on which the resin composition of the present invention is applied is mainly an aerospace device such as an aircraft and a rocket fairing, and various heating furnaces, electric heaters such as ovens, and building materials. It can be widely applied without limitation.

Example Two kinds of resin compositions having different composition (parts by weight) shown in Table 1 were produced.

In Table 1, a polyethylene glycol UE101 having a glycidyl group terminal manufactured by Yokohama Rubber Co., Ltd. as a polyalkylene glycol polymer A, an epoxy resin ELM434 manufactured by Sumitomo Chemical Co., Ltd. as an epoxy resin B, an amine compound As C, 1,3-BAC manufactured by Mitsubishi Gas Chemical Co., Ltd. was used.

As silica balloon D, ECCOSPHERE SI manufactured by Nippon Silica Co., Ltd. was used, and as phenol balloon E, BJO-0930 manufactured by UCC was used.

For comparison, urethane-modified epoxy resin 100 parts by weight,
A resin composition comprising 20 parts by weight of polyamidoamine, 120 parts by weight of phenol balloon, and 10 parts by weight of glass chop was prepared (Comparative Example 2).

These three types of resin compositions were applied to a thickness of 3 mm and cured at room temperature (24 ° C.) for 72 hours to produce a heat insulating material.

In this case, the resin compositions of Comparative Example 1 and Example 1 were diluted using methyl ethyl ketone, and Binks 7E2
It was applied to an aluminum plate with a thickness of 3 mm using a spray gun and cured by heating at room temperature (24 ° C.) for 72 hours.

In addition, since the resin composition of Comparative Example 2 was difficult to be diluted with a solvent, it was casted (or coated with iron) as it was.
Similarly, it was applied to the aluminum plate to a thickness of 3 mm (using an oven as a heating facility) and cured by heating at 60 ° C. for 8 hours.

The workability of the resin composition of Comparative Example 2 was inferior to the resin compositions of Comparative Example 1 and Example 1.

Density (g / cm ³ ), thermal conductivity (w / m, k) at 80 ° C, room temperature (24 ° C) and tensile strength at 200 ° C (Kgf / cm ² ), room temperature (24 ° C) ) And flatwise adhesive strength (Kgf / cm ² ) at 200 ° C. were measured. In addition, a heating test was performed. The results were as shown in Table 2.

The density, thermal conductivity, tensile strength, flatwise adhesive strength, and heating test were measured by the following methods.

Density: Measured according to the method specified in ASTM D792.

Thermal conductivity: Measured according to the method specified in JIS-A-1412.

Tensile strength: Measured according to the method specified in ASTM D 638.

Flatwise adhesive strength: Measured according to the method specified in US Military Standard (MIL-STD) 401.

Heating test: Heat with a gas burner and adjust the surface temperature to 500 ° C. The appearance when heated at 500 ° C. for 5 minutes was observed.

From Table 2, the resin composition of the present invention (Example 1) has a lower thermal conductivity than Comparative Example 2, and also has a large tensile strength at room temperature and at a high temperature of 200 ° C. In addition, the flat wise adhesive strength is slightly lower at room temperature but higher at 200 ° C., and it can be seen that the decrease by heating is small. In addition, no cracks or powders are generated by the heating test, and the mechanical properties are excellent. Further, the resin composition of the present invention (Example 1) is inferior in heat conductivity to Comparative Example 1, but at room temperature (24 ° C.).
And high tensile strength at a high temperature of 200 ° C, and excellent flat wise adhesive strength.

〔The invention's effect〕

In the resin composition of the present invention, the resin component I of the matrix containing the microballoons II is composed of the polyalkylene glycol polymer A having a glycidyl group at the end, the epoxy resin B, and the amine compound C. The resin component I itself has remarkably excellent adhesiveness, can be applied without using an adhesive, can be diluted with a solvent, can be applied by spray coating, and can be cured at room temperature. Can be constructed without the need for heating equipment. Further, the construction portion has excellent mechanical properties and flexibility without cracking or peeling due to large deformation, thermal shock, impact load and the like. On the other hand, since the silica balloon D, which is lightweight and has excellent heat insulation and shape retention properties, is used as the microballoon II, heat insulation properties and shape retention properties are exhibited without increasing the thickness, and the weight can be advantageously reduced. Furthermore, by using the phenol balloon E in combination with the silica balloon D, the weight can be further reduced and the heat controllability can be imparted.

Continuation of the front page (51) Int.Cl. ⁶ identification code FI C08L 61:06) (72) Inventor Tomohisa Nakamura 2-4-1 Hamamatsucho, Minato-ku, Tokyo Inside the Space Development Corporation (72) Inventor Fujita Takeshi 2-4-1 Hamamatsucho, Minato-ku, Tokyo Space Development Corporation (72) Inventor Nobuharu Niwa 1 Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries Gifu Plant (72) Inventor Chihiro Motoyama 1 Kawasaki-cho, Kakamigahara City, Gifu Prefecture Kawasaki Heavy Industries, Ltd. Gifu Factory (72) Inventor Yoshiaki Someya 2-1 Oiwake, Hiratsuka-shi, Kanagawa Prefecture Yokohama Rubber Co., Ltd. Hiratsuka Factory (72) Inventor Shuyoshi Kosugi Hiratsuka, Kanagawa Prefecture 2-1 Oitai, Yokohama Rubber Co., Ltd. Hiratsuka Factory (72) Inventor Isamu Fujiwara 2-1 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd. Hiratsuka Factory (56) References JP-A-62-79257 (JP, A) JP-A-54-150498 (JP, A) JP-A-2-124493 (JP, A) JP-A-2-117914 (JP, A) JP-A-63-125519 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08L 63/00-63/10 C08L 61/06 C08G 59/50 C08G 59/20-59 / 38 C08K 7/22-7/28

Claims (1)

(57) [Claims] 1. A mixture comprising a polyalkylene glycol polymer A having at least two glycidyl groups at its terminals, an epoxy resin B and an amine compound C, wherein the mixing ratio A of the polyalkylene glycol polymer A to the epoxy resin B is / B is a resin component I having a weight ratio of 25/75 to 75/25, and a mixing ratio D / E of a microballoon D composed of borosilicate silica and a microballoon E composed of a phenol resin is 50 / weight ratio.
Microballoon II of 50-100 / 5.1, mixing ratio I / II
Is a lightweight heat-insulating resin composition blended such that the weight ratio is in the range of 25/75 to 75/25.