JP2556067B2 - Flame retardant laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is a flame-retardant laminate obtained by bonding a prepreg made of a matrix resin containing at least a resol-type phenol resin and an inorganic filler and an aluminum foil with a urethane adhesive. Regarding goods.

(Prior art and its problems) Up until now, the interior of buildings, vehicles, etc. has been covered with wallpaper in order to give it a beautiful appearance. There are problems that it may cause the spread of fire, may cause a secondary disaster due to smoke generation or flashover, and may be easily damaged by the force from the room due to insufficient strength.

In particular, when it is used in a non-open room such as a high-rise building or high-speed transportation equipment and a fire or the like occurs therein, the damage is great, and it is necessary to solve this problem immediately.

Usually, a so-called flame retardant containing halogen or phosphorus is added to increase the flame retardancy of plastics, but it is effective in improving flame retardancy, but the amount of heat generated by forced combustion. Is not small, and is known to generate toxic gas such as hydrogen halide.

Among plastics, phenol resin is the most excellent from the viewpoint of flame retardancy, but its calorific value during combustion is not so small and its improvement has been desired. In addition, it has the effect of preventing the propagation of flames and lowering the combustion temperature, and also prevents the permeation of moisture and gas other than during combustion, and also uses a laminate containing aluminum foil that also has an electrostatic shielding effect. It can be considered, but in that case, the weak adhesion with the phenol resin was a problem.

(Means for Solving the Problems) The inventors of the present invention have conducted extensive studies to improve such drawbacks, and as a result, prepreg and aluminum foil impregnated with a matrix resin containing a resol-type phenolic resin and an aluminum foil are made of a urethane oligomer. By adhering, a flame-retardant laminate having flame retardancy, a small heat generation amount even when compulsorily burned, and excellent adhesiveness to each layer was found, and the present invention was completed.

The present invention provides at least 20 resole phenolic resins.
At least 1 comprising a matrix resin containing at least 10% by weight of an inorganic filler and a fiber reinforcement.
Provided is a flame-retardant laminate obtained by bonding a layer prepreg and an aluminum foil with a urethane adhesive.

Examples of the prepreg used in the present invention include those detailed below.

(1) Impregnated base material A base material that is impregnated with a normal resin such as a woven cloth, a non-woven cloth, a mat shape, and a paper shape and is dried to be B-staged to form a so-called prepreg, and its form is not limited. Among them, woven cloth is preferable because it is economically the most expensive, but when strength is required. Such a woven fabric may be combined with other base materials such as a woven fabric and a non-woven fabric, a woven fabric and a mat, instead of the single layer, and the combination thereof is not particularly limited. When the flame-retardant laminate is used as an interior surface material, an appropriate grain pattern is applied, but when a woven fabric is used as the base material, the texture may affect the grain pattern, and the price is high. For that reason, other substrates can be used in place of the woven fabric.

Glass fiber, carbon fiber, aramid fiber, other ceramic fiber or the like can be used as the type of fiber constituting the substrate. Especially when aiming for a low price, glass fiber is preferable, and when focusing on weight reduction, aramid fiber is suitable.

(2) Matrix resin As the matrix resin with which the above-mentioned base material is impregnated, a resin containing at least 20% by weight, preferably 30 to 90% by weight of a resole-type phenol resin is used. Further, in order to impart flame retardancy to the matrix resin as an inorganic filler, 10% by weight or more of an inorganic filler such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, alumina molybdenum oxide, antimony oxide, calcium oxide or magnesium oxide is used. 0 to 50 so-called flame retardants containing halogens, phosphorus atoms, etc.
It can be added in a weight percentage. In addition, other thermosetting resins such as epoxy resins and thermoplastic resins such as nylon resins and ethylene vinyl acetate copolymer resins are used in an amount of 0 to 40% by weight for the purpose of improving the strength and flexibility of the matrix resin. Can be mixed.

The resol type phenolic resin used in the present invention preferably has a total of 1.0 to 3.0 times moles of hydroxymethylene groups and methylene groups connecting benzene rings per mole of phenol. Such resol type phenolic resin is a phenol having a hydroxyl group directly bonded to an aromatic ring such as phenol, cresol, resorcinol, caracol, paratertiarybutylphenol, paratertiarybutyl, and catechol, and aldehydes such as formaldehyde, paraformaldehyde and trioxane. It is made by reacting a compound such as tetrazine or tetramine which adds a methylene group under an alkali catalyst. The hydroxymethylene group in the resol-type phenol resin crosslinks during polymerization, which is one of the factors giving low smoke generation performance. If the total of the hydroxymethylene group and the methylene group is more than 3.0 times the molar ratio of phenol, it becomes hard and brittle when polymerized, while if less than 1.0, it becomes difficult to polymerize.

As such a resole-resistant phenol resin, for example, a phenol resin commercially available under the trade name "Priofen" manufactured by Dainippon Ink and Chemicals, Inc. can be used.

Aluminum hydroxide and / or magnesium hydroxide is preferably added to the matrix resin for the purpose of imparting flame retardance and low smoke generation. The amount thereof is preferably added in such a proportion that it accounts for 10 to 60% by weight of the whole resin composition, more preferably 20 to 50% by weight. Of these two, aluminum hydroxide [Al (OH) ₃ ] is more suitable because it has a small proportion of increasing the viscosity of the compound.

The prepreg used in the present invention preferably contains the above-mentioned phenol resin and aluminum hydroxide and / or magnesium hydroxide, which may be contained in a state where they do not react with each other, or a part of them may be pre-reacted. You may contain the thing made to do.

The prepreg used in the present invention has a viscosity adjusted by adding a solvent such as methyl ethyl ketone, acetone, or methanol to a pre-blended matrix resin, and then impregnated into the impregnated base material, followed by removal of the solvent and matrix resin B-
It can be obtained by heating and drying for the purpose of forming a stage.

The prepreg used in the present invention has a suitable resin content of 20 to 50% by weight, for example, a matrix resin composition having a viscosity of 100 centiboise diluted with methyl ethyl ketone of 300 g / m ² is used. It can be obtained by impregnating a woven glass cloth having a weight and drying at 100 ° C. for 10 minutes.

Next, the aluminum foil which is a feature of the present invention will be described.

The thickness of the aluminum foil used in the present invention is not particularly limited, but it is practically used in a thickness of 10 to 100 μm, particularly 10 to 5 μm.
A thickness of 0 μm is optimal. The aluminum foil is not particularly limited, and commercially available aluminum foil can be used.

When the aluminum foil is pressure-molded, its adhesive strength is weak, especially when it is in direct contact with the above-mentioned phenol prepreg. In the present invention, the adhesive strength can be greatly improved by applying the urethane adhesive between them in a thickness of preferably 2 μm or more. Further, when the thickness is 50 μm or more, the adhesive layer burns at the time of burning and remarkably deteriorates the flame retardant property of the whole. Therefore, the more preferable thickness is 4 to 15 μm. As the urethane-based adhesive used, it retains the initial adhesive force when it is used for a considerable time after the adhesive is applied to the aluminum foil, for example, when it is used several months after the adhesive is applied. A thermoplastic urethane adhesive is preferable, and a two-component urethane adhesive of polyol and polyisocyanate can also be used.

The thermoplastic urethane adhesive is a polyurethane obtained by reacting a polyol-containing compound with an isocyanate group-containing compound, preferably having a molecular weight of 500 to 1,000,000, optimally 100 to 100,000 or a solution thereof, or a dispersion thereof. The present invention is not limited to the above, but may be pellets obtained by removing the solution to form a solid product only. The typical ones are listed below. Molecular weight of aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and polyols such as ethylene glycol and neopentyl glycol
As 1000 polyester polyols and isocyanates
4,4'-Diphenylmethane diisocyanate (MDI)
And can be obtained by reacting OH: NCD = 1: 0.97 (molar ratio) in methyl ethyl ketone at 65 ° C. for about 5 hours. In this case, a polyurethane adhesive having a solid content of 30% and a viscosity of 1000 cps is obtained. Typical examples of such a thermoplastic urethane adhesive are commercially available products under the trademarks such as Pandex (a product of Dainippon Ink and Chemicals, Inc.), Chris Bonn (same as left), Bondic (same as left) and the like.

The urethane-based adhesive used in the present invention is usually used by coating it once on an aluminum foil, but it is difficult to react all polyols and polyisocyanates, so some unreacted parts remain. But it's okay. When used for the purpose of higher adhesiveness, unreacted isocyanate is particularly effective, and some unreacted isocyanate may be intentionally left.

Other hot melt adhesives, such as acrylic,
50% by weight of a vinyl-based, polyester-based, polyamide-based hot-melt adhesive to the urethane adhesive of the present invention
It can be added within the range not exceeding.

The flame-retardant laminate of the present invention is one in which the prepreg and the aluminum foil are adhered with a urethane adhesive, and the prepreg is adhered to the front and back of the aluminum foil with a urethane adhesive, or the prepreg is It may be a laminate of two or more layers on one side or both sides of the aluminum foil.

Next, the flame-retardant laminate of the present invention is particularly useful as an interior surface material, and typical examples of the interior surface material are shown below. A transparent film with hot melt adhesive applied on one side is used as the outermost layer. Further, a printed film or paper is laminated on the inside. The film of the outermost layer or the film and paper used for the innermost layer is not particularly limited as long as it can withstand heat and pressure molding, but when used as the outermost layer, it is essential that it is transparent. As such a film, for example, polyester, polyamide, polyvinyl fluoride, polyvinylidene fluoride, polyether ether ketone, polysulfone, polyphenylene sulfide, polythioether sulfone, polyphenylene sulfide, polythioether sulfone, polyimide, etc. are most suitable. is there.
The use of paper is not particularly limited, but a material imparted with flame retardancy is more suitable.

Further, in order to fix the unevenness on the inner surface of the printed film or paper, in order to fix the unevenness, for example, a prepreg is laminated, or a flame-retardant laminate in which both sides of the aluminum foil are laminated with a prepreg is used. It can be laminated. At this time, the prepreg is preferably the phenol prepreg used in the flame-retardant laminate. However, as the base material, use soft organic fibers so that they do not get in the way when making irregularities on the surface, or use hard fibers such as glass fibers in the form of a mat that combines fibers of 10 cm or less, or It is desirable to use it as a mat or paper combined with other soft organic fibers. When used in the form of a woven fabric, it is desirable to use a woven fabric with the finest mesh possible.
When organic fibers are used for a part or all of the base material of the prepreg, a material having both heat resistance and flame retardancy, such as aromatic amide fiber, is most suitable.

When using the laminate according to the present invention as an interior,
A general method is to either stick it to another wall material via an adhesive, or form it integrally with another wall material before use.

In the case of high-speed transport aircraft, especially interior materials such as aircraft,
The honeycomb structure is often used as a base material for a wall material in order to keep the strength as a wall while being lightweight.

As a method of manufacturing an interior material having a honeycomb structure as a base material, first, a sandwich panel having a honeycomb structure made in advance as a core is prepared, for example, the above-mentioned interior surface material, that is, a transparent film, Printed film
An adhesive or pressure-sensitive adhesive in which the transparent film layer is the outermost layer and the sandwich panel in which the prepreg and the flame-retardant laminate of the present invention are sequentially laminated so that the prepreg layer of the flame-retardant laminate is the outer surface. It is a method of sticking. As the adhesive in this case, a two-component type adhesive such as a polyurethane adhesive or an epoxy adhesive which is hardened at room temperature is often used.

The second is a method in which prepregs are applied to both sides of the honeycomb structure, and the interior surface material by the above-mentioned method is applied to the surface side of the honeycomb structure to heat and press-mold it.

In the present invention, the method of use is not particularly limited, and any one of the above methods may be used.

(Example) Next, the present invention will be described according to an example.

[Preparation of prepreg]

60% by weight of a resole-type phenol resin R-53 (manufactured by DIC) having a hydroxymethylene / phenol molar ratio of 1.6 / 1,
As polyamide resin, 15% by weight of laccamide 5003 (manufactured by DIC) and 25% by weight of aluminum hydroxide (first-grade reagent) were uniformly mixed in methanol to obtain a compounding solution having a viscosity of 100 centipoise.

A glass cloth S having a basis weight of 300 g / m ²
Impregnate LS 213B (made by Asahi Fiber Glass Co., Ltd.) at 100 ° C,
Prepreg I was made by drying for 10 minutes. The resin content was 40% by weight.

Reference example 1. Two-component urethane adhesive on one side (Ciba-Geigy)
25 μm thick transparent polyvinyl fluoride film coated with, 38 μm thick polyvinyl fluoride film printed on one side, and epoxy prepreg (Ausbon W-31
00G, manufactured by Dainippon Ink and Chemicals, Inc., 130 ℃, 15kg / cm
^It was press-molded under a pressure of ² for 1 hour to make a laminate having a thickness of 200 μm.

As a result of a vertical combustion test according to JISL-1091A-4, the surface film was extremely heavily burned, and the afterflame time was 25 seconds and the burning distance was 20 μm.

Example 1 A 25 μm thick transparent polyvinyl fluoride film (Du
Two-component urethane adhesive (made by pont)
(Manufactured by the company) with a thickness of 10 μm.

In addition, 38 μm thick polyvinyl fluoride film with one side printed, phenol prepreg (Ausbon W-
6304G, made by Dainippon Ink and Chemicals, Inc.) Aluminum foil with a thickness of 10 μm, both sides of which are coated with thermoplastic urethane adhesive Crisbon AH 810 (made by Dainippon Ink and Chemicals) on both sides, and the above-mentioned phenol prepreg 1 13 sheets in sequence
Press molding under pressure of 0 ℃, 15kg / cm ² for 1 hour to obtain a thickness of 300
A μm laminate was made. The resulting laminate showed good adhesion to aluminum foil. This was subjected to a vertical combustion test according to JIS L-1091A4. The combustion on the surface of the film surface was small, the afterflame time was 5 seconds, and the combustion distance was 10 cm.

Example 2 A two-pack type urethane adhesive was applied to one side of a transparent PPS film having a thickness of 25 μm in a thickness of 10 μm.

In addition, 38 μm thick polyvinyl fluoride film with one side printed, phenol prepreg (Ausbon W
-6304G, manufactured by Dainippon Ink and Chemicals, Inc. 1 each of 20 μm thick aluminum foil coated with thermoplastic urethane adhesive Crisbon AH810 (manufactured by Dainippon Ink and Chemicals) on both sides with a thickness of 6 μm and the above-mentioned phenol prepreg 13 sheets in sequence
Press-molded at 0 ℃ and 15kg / cm ² for 1 hour to obtain a thickness of 300
A μm laminate was made. The resulting laminate showed good adhesion to aluminum foil. When this was subjected to a vertical burning test according to JIS L-1091A4, it was found that the afterflame time was 2.0 seconds and the burning distance was 8 cm, and there was no afterflame on the film surface, and the flammability was clearly superior to the reference example. It was

Claims (1)

(57) [Claims] 1. A urethane-based adhesive comprising at least one layer of a prepreg comprising a matrix resin containing at least 20% by weight of a resol type phenolic resin and at least 10% by weight of an inorganic filler and a fiber reinforcement and an aluminum foil. Flame-retardant laminated board bonded with a chemical.