JP2001205720A - Method of manufacturing honeycomb core for sandwich structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a honeycomb core which keeps excellent characteristics of heat insulation, sound insulation, rigidity, etc., and is uniform in the content of foams of each cell. SOLUTION: A mixture containing a dispersion or water solution of a phosphoric acid or the like (a), a curing agent (b), a urethane prepolymer having an NCO group (c) and a foaming agent as occasion demands (4) is filled in the cells of a honeycomb body of a cell size 3-100 mm and voids 92-99.5%, with a temperature maintained at -15-+15 deg.C, and foamed and cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a honeycomb core material for a sandwich structure, and a sandwich structure using the manufactured honeycomb core material.

[0002]

2. Description of the Related Art Conventionally, a sandwich structure in which a honeycomb core material is sandwiched by a rigid surface material such as a steel plate has excellent characteristics such as light weight, rigidity, sound insulation, and heat insulation. Etc. are widely used as interior or exterior panels of building materials, and structural materials for aircraft, vehicles and the like. Among various characteristics of these structures, a honeycomb core material in which cells of a honeycomb body are filled with a resin foam in order to improve sound absorption and heat insulating properties is also disclosed in JP-B-3-61581 and JP-A-8-174773. It is disclosed in the gazette

However, in recent years, there has been an increasing demand for non-combustibility in order to ensure safety in the event of fire. In the honeycomb core material filled with the above resin foam, since the resin is an organic substance such as a phenol resin, it is used in applications as a non-combustible material. Had limitations.

In a conventional honeycomb core material filled with a resin foam, since the resin foam filled in the cells is hard and brittle, the foam tends to fall out of the cells when it is bent due to transportation or the like. The transportability and handleability were poor. Alternatively, in a state in which the resin foam is not filled in the entire cells of the honeycomb core material, the heat insulating property of the honeycomb core material was uneven or poor. For this reason, Japanese Patent Laid-Open No. 1-30
In Japanese Patent No. 1329, a foam is prevented from falling off by providing a cutout at one end of a cell wall of a honeycomb core material in one direction. However, in this case, there is a problem that the mechanical strength, particularly the shear strength is inferior because the partition walls are not continuous.

In addition, when the resin foam filled in the cells is hard, when the foam is unevenly filled or shrinks upon curing when producing a flat sandwich structure, it is difficult to obtain the resin foam. The resulting honeycomb core flexed and did not form a uniform flat surface, so that the resulting sandwich structure also had poor smoothness. For this reason,
Japanese Patent Application Laid-Open No. Sho 60-210429 discloses a honeycomb core material in which a gap is bent with a spacer interposed therebetween. However, in this case, it takes time and effort to insert a spacer, and since the honeycomb core material and the surface material are not directly bonded, the adhesiveness is poor, and the obtained sandwich structure is not uniformly filled with cells. Therefore, there is a problem that the mechanical strength, particularly the shear strength is inferior.

Further, conventionally, when it is attempted to obtain a sandwich structure having a curved surface, it is difficult to form a curved surface shape after manufacturing with a hard resin foam, so that the honeycomb body is set on the curved surface in advance and the foam is filled. I had to take such a method.

On the other hand, Japanese Patent Application Laid-Open No. 9-157061 discloses phosphoric acid foams which can be molded with a foam under normal temperature and normal pressure conditions and have excellent nonflammability and fire resistance. . However, such foams are flexible and elastic, and as such, may not be sufficient as structures requiring rigidity.

[0008]

Accordingly, the present inventors have developed a flame-retardant honeycomb comprising an inorganic foam comprising phosphoric acid and a foam hardener thereof, and an organic foam comprising a urethane prepolymer having an NCO group. It is filled with a composite foam, and while maintaining the heat insulation and sound insulation of a honeycomb core material filled with a conventional resin foam, it has flexibility and elasticity, and cannot be obtained with a conventional resin foam. Honeycomb that is excellent in flame retardancy and nonflammability, and has high adhesiveness between the honeycomb body and the resin foam, so that transportability and handleability are improved, and the honeycomb can also be used for manufacturing a sandwich structure having a curved surface shape. Patent Application No. 11-3359
No. 02 was proposed.

[0009] However, in the honeycomb core material proposed above, the content of the foam in each honeycomb cell may not be uniform, and the honeycomb cell may vary, and therefore, the honeycomb core material may be formed on both surfaces of the honeycomb core material. It has been found that the sandwich structure to which the surface material is adhered has variations in terms of heat insulation, sound insulation, rigidity, and the like, and has a problem that it is difficult to obtain uniform performance.

[0010] The present invention solves the above-mentioned problems, and maintains the excellent characteristics of the honeycomb core material filled with the composite foam, while ensuring that the content of the composite foam in each honeycomb cell is uniform. Accordingly, the present invention provides a method for manufacturing a honeycomb core material having uniform performance even in a sandwich structure formed from the honeycomb core material without variation in heat insulation, sound insulation and rigidity. is there.

[0011]

According to the study of the present inventor, the variation in the content of the foam generated in each honeycomb cell of the honeycomb core material is caused by the above-mentioned organic and inorganic composite in the manufacturing process of the honeycomb core material. It has been found that the foaming reaction of the foam is due to an unexpectedly fast foaming reaction. That is, in the process of filling the mixture of each of the above-described components that are the raw materials of the foam into the cells of the honeycomb body, uniformly diffusing the mixture into all the cells performs adjustment such as reducing the viscosity of the mixture. However, it is surprisingly difficult, and therefore, it is difficult to uniformly fill the mixture forming the foam into the honeycomb cells, and as a result, the content of the foam in each cell varies, resulting in non-uniformity.

In the present invention, the present invention has been achieved as a result of repeated studies to find a means for easily filling the mixture as a raw material of the foam to eliminate the dispersion of the mixture and to make the mixture uniform.

[0013] Thus, the present invention relates to JIS-A6931.
For a honeycomb cell having a cell size of 3 to 100 mm and a porosity of 92 to 99.5%, a dispersion or aqueous solution of phosphoric acids (a), a curing agent (b), and an NCO group are defined. Urethane prepolymer (c) having
And if necessary, a mixture containing a foaming agent (d),
A method for manufacturing a honeycomb core material for a sandwich structure, characterized in that the material is filled at a temperature of + 15 ° C. and foamed and cured.

According to the present invention, by controlling the temperature of the mixture forming the foam, especially the dispersion of the phosphoric acid which is a component of the mixture or the temperature of the aqueous solution (a) in a specific range, the rise of the foaming of the mixture is started. By controlling the time, the mixture can be uniformly and sufficiently diffused and easily filled in the honeycomb cells.According to the present invention, the content of the foam in each cell varies. A small and highly uniform honeycomb core material can be obtained.

[0015] Thus, the honeycomb core material according to the present invention comprises:
In addition to the above points, since the foam contained in the cell is a composite foam of inorganic and organic, it has excellent flame retardancy and non-flammability that cannot be obtained with conventional organic foam, and the conventional inorganic foam. It is flexible and elastic that cannot be obtained by the body. Further, since the foaming and expanding power of the foam gives extremely large adhesion between the honeycomb and the filler in combination with the adhesion of the originally large urethane polymer, the honeycomb core material according to the present invention comprises It is easy to transport and handle without falling off, and it has flexibility, so it can be deformed after manufacturing, it has good flat surface material attachment, and it can be applied to structures with curved surfaces It is possible to do.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The honeycomb body forming the honeycomb core material of the present invention,
It has a form having substantially continuous geometric cells (through holes), such as polygons such as hexagons, squares, and triangles, circles, and non-equilateral polygons, which are separated by partition walls made of a continuous member. The cell size and porosity of the honeycomb body are as follows:
It relates to the stiffness of the manufactured honeycomb core material,
Specified by IS-A6931. The cell size is shown in FIG.
m, especially 5 to 50 mm, is suitable. The porosity is (the volume occupied by the honeycomb body-the volume of the partition wall material of the honeycomb body).
定義 Defined by the volume occupied by the honeycomb body. In the present invention, 92 to 99.5%, particularly 93 to 98% is appropriate.

When the porosity of the honeycomb body is smaller than the above range, the foam easily adheres to the partition walls of the cell during filling, making the filling difficult, and the proportion of the honeycomb material occupied by the honeycomb material increases, so that the honeycomb material easily conducts heat. By increasing the amount of C, the heat insulating properties of the honeycomb core material decrease. On the other hand, when it is large, the proportion of the honeycomb material is small, and the strength of the honeycomb core material is reduced, which is inappropriate. The wall thickness of the partition wall of the honeycomb body has an inverse relationship with the porosity, but is preferably 0.02 to 3 mm.

The thickness of the honeycomb body is shown in FIG. 1 (g), and is appropriately selected depending on the required heat insulation, sound insulation, fire protection and the like. For example, in an office partition, 50m
m or less, and preferably 40 mm or more when fire protection and fire resistance are required. In addition, in the case of a refrigeration panel or the like that requires heat insulation, 20
0 to 400 mm is preferred.

Examples of the material of the honeycomb body include metal honeycombs such as aluminum, stainless steel, and steel; paper honeycombs such as kraft paper, aramid paper, paper containing magnesium silicate or aluminum hydroxide; plastics such as vinyl chloride, polypropylene, and polyethylene. Honeycomb; ceramic honeycomb such as cordierite and mullite; ceramic paper honeycomb such as alumina and alumina silica fiber. Among them, for reasons of fire resistance, flame retardancy, lightness of unit weight and price, etc., 40% by weight of the ash residue in the test specified in JIS-P8128 such as aluminum honeycomb, steel honeycomb, magnesium silicate or aluminum hydroxide. % Is preferred.

As the aluminum honeycomb, JI
5052, 5056, 2 specified in S-H4000
Generally, a foil using an aluminum alloy such as 024, 3003, 3004, etc. is used. As the above-mentioned steel honeycomb, a foil of a relatively low carbon steel is bonded with an adhesive, and is used after being spread. Is preferred. Further, the metal honeycomb may be a so-called corrugated honeycomb obtained by bonding a metal foil formed into a corrugated shape, and these metal honeycombs are subjected to a corrosion-resistant coating treatment as necessary.

The flame-retardant paper honeycomb containing aluminum hydroxide or magnesium silicate is obtained by forming aluminum hydroxide or magnesium silicate together with organic fibers such as pulp or inorganic fibers such as glass fibers into a paper. Are preferably bonded and then spread.

The filler to be filled in the honeycomb body according to the present invention comprises an inorganic foam comprising a dispersed or aqueous solution of phosphoric acid (a), a curing agent (b) and, if necessary, a foaming agent (d);
It is composed of a composite foam with an organic foam composed of a urethane prepolymer (c) having an O group. The curing agent (b) and the foaming agent (d) forming the inorganic foam may be a single agent having both functions, or may be different from each other. Such an inorganic foam is excellent in flame retardancy and rigidity, but there is a danger of brittleness, but the foam of the present invention is significantly improved in brittleness by being composited with an organic foam made of a urethane prepolymer. You.

The ratio of the inorganic foam to the organic foam in the composite foam is determined by the physical properties of the filler in the present invention, and
Although related to the characteristics of the honeycomb core material, the ratio (weight basis) of inorganic foam / organic foam is preferably 3/1 to 5
0/1. When this ratio is 3/1 or more, flame retardancy and fire resistance are good, while when it is 50/1 or less, the film does not become brittle and has good adhesion and flexibility. Especially, this ratio is more preferably 10/1 to 50/1.

The honeycomb core material of the present invention comprises a dispersion or aqueous solution of phosphoric acid (a), a curing agent (b), a urethane prepolymer having an NCO group (c), and, if necessary, a foaming agent. A mixture comprising (d)
The temperature is adjusted to −15 ° C. to + 15 ° C., the temperature is maintained at the temperature, filling is performed, and foaming and curing are performed. In this case, it is important to control the temperature of the mixture within the above range as described above. By controlling the rapid foaming hardening of the aqueous mixture, the unfoamed state, that is, the time having fluidity, becomes longer, for example, the thickness can be made uniform by a doctor blade or the like. Can be uniformly filled. Further, since it becomes possible to fill the cells of the honeycomb body before the aqueous mixture foams, the honeycomb body does not break the foam bubbles, and as a result, stable and uniform foaming is performed, and the honeycomb is formed. It is possible to improve the heat insulating property as the core material and to reduce the weight.

When the temperature of the mixture exceeds 15 ° C., the rate of the foaming and curing reaction of the mixture is increased, the fluidity is reduced, and the mixture is uniformly diffused in the cells of the honeycomb. It becomes difficult to fill the cell. On the other hand, when the above temperature is lower than -15 ° C, the dispersion of the phosphoric acid or the aqueous solution or the reactivity of the urethane prepolymer having an NCO group becomes extremely poor. It causes gradual collapse or hardening of the foam before curing. In particular, the temperature of the mixture is preferably -5 to + 10C.

When controlling the temperature of the mixture, all the components contained may be controlled to the above-mentioned temperature, or may be controlled to the above-mentioned temperature range during or immediately after the mixing. However, from the viewpoint of the easiness of the means and the effect obtained, it is preferable to carry out the treatment by dispersing the phosphoric acids contained therein or controlling the temperature of the aqueous solution. Thus, the temperature of the phosphoric acid dispersion or aqueous solution (a) is preferably adjusted to -2.
0 to + 10 ° C., and other components such as a hardener (b), a urethane prepolymer (c), and, if necessary, a foaming agent (d) in a phosphoric acid dispersion or aqueous solution (a) maintained at such a temperature. ), A mixture in the above temperature range is obtained.

If the temperature of the above-mentioned phosphoric acid dispersion or aqueous solution (a) is lower than -20 ° C., the reactivity of not only the aqueous phosphoric acid solution but also the urethane prepolymer having an NCO group deteriorates, so that the time until curing is reduced. And the foamed cells gradually disintegrate before curing or cause sedimentation of the foam. On the other hand, when the temperature exceeds 10 ° C., the foaming and curing reaction speeds are increased, and the fluidity of the aqueous mixture is reduced. Therefore, it is difficult to uniformly diffuse and fill the honeycomb body. The temperature of the dispersion or aqueous solution (a) of the above-mentioned phosphoric acids is preferably -10
~ + 5 ° C is particularly suitable.

The method for measuring the temperature of the mixture or the dispersion of the phosphoric acid or the temperature of the aqueous solution (a) is not particularly limited, and a mercury thermometer and an alcohol thermometer utilizing thermal expansion, a thermocouple, a platinum resistance, a thermometer, and the like. Non-contact type thermometers such as a contact thermometer using a mr or a radiation thermometer using an infrared ray may be mentioned.In particular, when measuring the above mixture, the mixture starts a reaction and foaming starts. Therefore, it is necessary to measure quickly, and it is preferable to use a radiation thermometer when measuring the mixture.

In the composite foam of the present invention, examples of the phosphoric acid forming a dispersion or aqueous solution (a) of phosphoric acid include phosphoric acid, phosphorous acid, phosphoric anhydride, condensed phosphoric acid, and metals of these phosphoric acids. Salts or mixtures of two or more of these. The metal salt of phosphoric acid herein includes a metal salt of acidic phosphoric acid, and the metal salt of acidic phosphoric acid refers to a metal phosphate having at least one hydroxyl group bonded to a phosphorus atom. The present invention is preferably employed because the use of the above-mentioned acidic metal phosphate can improve the water resistance and moisture resistance of the foam and, as a result, can increase the cell strength of the foam. As the above metals, sodium, potassium, magnesium,
Examples thereof include calcium, aluminum, zinc, barium, and iron, and polyvalent metal salts such as magnesium, calcium, aluminum, zinc, barium, and iron are preferable in terms of further improving the water resistance and cell strength of the foam. Other than the method of adding in the form of these metal phosphates and metal phosphites,
Metal compounds chemically active with phosphoric acid and phosphorous acid, for example, polyvalent metal oxides such as magnesium oxide and calcium oxide, and polyvalent metal hydroxides such as aluminum hydroxide gel, magnesium hydroxide and calcium hydroxide It is also possible to employ a method in which a substance or the like is separately added to an aqueous solution of a phosphoric acid such as phosphoric acid or phosphorous acid in the system and reacted in the system.

Of these, phosphoric acid, magnesium monophosphate, aluminum monophosphate, zinc monophosphate or a mixture of two or more of these is particularly preferred as the phosphoric acid dispersion or aqueous solution (a). . The reason is that the water resistance, the moisture resistance, the cell strength of the foam, and the like are high.
The aqueous solution of phosphoric acid referred to here is a solution of a water-soluble phosphoric acid such as a metal phosphate, phosphoric acid, phosphorous acid or the like in water using a solvent, and is adjusted to 50 to 90% by weight. The use of an aqueous phosphoric acid solution or an aqueous solution of a metal phosphate is preferably used because storage stability and handleability are improved. Further, the aqueous phosphoric acid dispersion refers to a dispersion in which a relatively low solubility in water such as a second metal phosphate is used, and the aqueous phosphoric acid solution and the aqueous phosphoric acid dispersion are They can be used alone, or they can be used in combination with adjusting the water content as needed.

As the phosphoric acid dispersion or aqueous solution (a), an acidic metal phosphate, particularly an aqueous solution of a polyvalent metal salt thereof, is preferably used in combination with a water-soluble amine. Examples of the water-soluble amines include secondary or tertiary alkylamines such as diethylamine, diisopropylamine, diallylamine, triethylamine and triallylamine; pyridine, piperidine, N-methylpiperidine, morpholine, N-methylmorpholine, N-ethylmorpholine. And heterocyclic amines such as lutidine; monoethanolamine, N, N-dimethylethanolamine,
Amino alcohols such as N, N-diethylethanolamine; and water-soluble amines having a boiling point at room temperature to about 200 ° C., such as urea, are preferred. Those that dissolve in water at 1% by weight or more are preferably employed.

The content of the phosphoric acid dispersion or aqueous solution (a) in the foam of the present invention is preferably 3 to 20% by weight in terms of the content of phosphorus atoms in the foam of the present invention. Particularly, 4 to 18% by weight is appropriate. If the content is less than 3% by weight, the fire prevention performance of the obtained foam may decrease. On the other hand, when the content exceeds 20% by weight, the dispersibility of the prepolymer (c) is reduced, and a uniform foamed structure may not be obtained.

In the foam of the present invention, as the curing agent (b), gas is reacted with a metal carbonate (b1), a metal oxide and / or a metal hydroxide (b2), or an acid or alkali to form a gas. The generated light metal (b3) is used.

Preferred examples of the metal carbonate (b1) (including ammonium carbonate) include sodium carbonate, sodium hydrogen carbonate, potassium carbonate, ammonium carbonate, calcium carbonate, barium carbonate, basic magnesium carbonate,
Basic zinc carbonate and the like can be mentioned. Among them, preferred are polyvalent metal carbonates such as basic magnesium carbonate.

Preferred examples of the metal oxide (b2) include sodium oxide, potassium oxide, calcium oxide,
Barium oxide, magnesium oxide, aluminum oxide,
Zinc oxide is exemplified, and the metal hydroxide (b2) is sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, aluminum hydroxide,
Zinc hydroxide. Among them, alkaline earth metal oxides such as magnesium oxide, calcium oxide, and barium oxide, or alkaline earth metal hydroxides such as magnesium hydroxide, calcium hydroxide, and barium hydroxide reduce the reaction time and improve the performance of honeycomb cells. It is preferable that at least one kind of the alkaline earth metal oxide or the alkaline earth metal hydroxide is contained as the curing agent (b), since the content of the foam inside becomes uniform. These alkaline earth metal oxides and alkaline earth metal hydroxides are highly reactive with the phosphoric acid dispersion or aqueous solution, so that self-heating is easily promoted, and the curing of the mixture reacted at a low temperature is more effectively performed. It is considered that the foam cells are easily promoted and the collapse of the foam cells is prevented.

Preferred examples of the light metal (b3) include magnesium, aluminum, zinc and the like.

The amount of the curing agent (b) used is preferably 0.1 to 200 parts by weight, based on 100 parts by weight of the phosphoric acid in the dispersion or aqueous solution (a) of the phosphoric acid. In the case of b1), since it also has the function of a foaming agent, considering the preferable range of the degree of foaming and curing, 1 to 150 parts by weight is particularly suitable.

The foaming agent (d) in the foam of the present invention comprises:
Depending on the type of the hardening agent (b), since it itself functions as a foaming agent, it is not necessary to use what is particularly called a foaming agent (d). That is, in the case of (b1) and (b3),
(B1) and (b3) also have the function of the foaming agent (d), while (b2) has only the function of the curing agent, so the foaming agent (d) is used. As such a foaming agent (d),
Examples include volatile low-boiling organic solvents or organic compounds that generate gas by thermal decomposition.

The above volatile low boiling point (boiling point of 120 ° C. or less)
Examples of the organic solvent include ethers, ketones, hydrocarbons and chlorofluorocarbons.
Preferred are halogenated hydrocarbons and ketones at 0 ° C,
Particularly, halogenated hydrocarbons and acetone which are liquid at room temperature are preferable. These foaming agents can be used alone or as a mixture of two or more.

Preferred examples of the ethers include diethyl ether and dipropyl ether, and preferred examples of the ketones include acetone and methyl ethyl ketone, and preferred examples of the hydrocarbons include pentane, hexane and heptane. , Cyclopentane, cyclohexane and the like. Preferred examples of the halogenated hydrocarbons include chlorinated hydrocarbons such as methylene chloride and trichloroethylene, and 2,2-dichloro-1,1,1,1-trifluoroethane (H
CFC123), chlorinated fluorinated hydrocarbons such as 1,1-dichloro-1-fluoroethane (HCFC141b),
And 1,1,1,2,3,3-hexafluoropropane (HF
C236ea), and fluorinated hydrocarbons such as 1,1,1,1,3,3-pentafluoropropane (HFC245fa).

Preferred examples of the organic compound which generates a gas by thermal decomposition include azo compounds such as azobisisobutyronitrile, azodicarbonamide and azobisformaldehyde; dinitrosopentamethylenetetramine and dinitrosoterephthalamide. A nitroso compound; P-
Sulfonyl hydrazide compounds such as toluenesulfonyl hydrazide, P, P'-oxybis (benzenesulfonyl hydrazide); methyl ethyl ketone peroxide;
Organic peroxides such as benzoyl peroxide and cumene peroxide; hydrazo compounds such as hydrazodicarbonamide, isopropyltolylhydrazinotriamine hydrazodicarboxylate and P-toluenesulfonylsemicarbazide are preferred. Compounds such as 5-phenyltetrazole, ammonium carbonate, ammonium bicarbonate, and urea can also be used.

In the present invention, the amount of the foaming agent (d) is preferably 0.5 to 50 parts by weight, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the phosphoric acid in the aqueous solution (a).
~ 45 parts by weight is suitable. When (b2) is used as the curing agent, the foaming time for the curing reaction can be appropriately adjusted by appropriately selecting the foaming agent with respect to the curing agent in order to use the foaming agent separately. The filling of the foam is sufficient. In addition, since the amounts of the curing agent and the foaming agent can be adjusted respectively, the range is a wide range from desired soft to hard, and it is easy to determine according to the expansion ratio.

In the present invention, the urethane prepolymer having an NCO group (c) is derived from an organic polyisocyanate compound and an active hydrogen-containing compound (h),
And those having an NCO group in the molecule. Preferred examples of the organic polyisocyanate compound have 2 to 2 carbon atoms.
Aliphatic polyisocyanate of 12 (excluding carbon in the NCO group, the same applies to the following isocyanates), alicyclic polyisocyanate of 4 to 15 carbon atoms, and 8 to 12 carbon atoms
And polyaromatic isocyanates having 6 to 20 carbon atoms, or modified products of these polyisocyanates. Preferred examples of these include hexamethylene diisocyanate (HDI),
Isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MD
I), methylcyclohexane-2,4-diisocyanate (hydrogenated TDI), 2,4- or 2,6-toluene diisocyanate (TDI), or 4,4′-diphenylmethane diisocyanate (MDI).

As the active hydrogen-containing compound (h),
For example, a low molecular weight polyol (h1) and a high molecular weight polyol (h2) can be mentioned. Here, (h1) and (h
When the range of each molecular weight in 2) is represented by a hydroxyl value,
The hydroxyl value of (h1) is usually from 300 to 1,000.
Or more, preferably 350-800. or,
The hydroxyl value of (h2) is usually less than 300, preferably 20-250, especially 40-200. The number of functional groups of the active hydrogen-containing compound (h) is (h1), (h
In each case of 2), it is usually 2 to 8 or more.

Examples of the low molecular weight polyol (h1) include the following (h1-1) to (h1-6). (H1-1) aliphatic dihydric alcohols, (h1-2) low molecular weight diols having a cyclic group, (h1-3) trihydric alcohols, (h1-4) tetrafunctional or higher polyhydric alcohols, (H1-5) alkanolamines, (h1-6) compounds of (h1-1) to (h1-5),
Low molar addition products of ethylene oxide and / or propylene oxide.

On the other hand, examples of the high molecular weight polyol (h2) include the following (h2-1) to (h2-6). (H2-1) polyoxyalkylene polyol, (h2-2) polyester polyol, (h2-3) polyolefin polyol, (h2-4) acrylic polyol, (h2-5) castor oil-based polyol, (h2-6) heavy Combined polyol.

Among the low molecular weight polyols (h1), specific examples of the aliphatic dihydric alcohols (h1-1) include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, Pentyl glycol, 1,6 hexanediol, 1,8 octamethylenediol and the like can be mentioned.

Specific examples of the low molecular weight diols (h1-2) having a cyclic group include 1,4-bis (2-hydroxyethoxyphenyl) propane. Specific examples of the trihydric alcohols (h1-3) include glycerin, trimethylolpropane, hexanetriol and the like. Specific examples of the polyhydric alcohols having four or more functional groups (h1-4) include sorbitol and shoux rose. Specific examples of the alkanolamines (h1-5) include triethanolamine and methyldiethanolamine. Specific examples of the low-molar adduct (h1-6) include, in addition to those listed as specific examples of (h1-1) to (h1-5), ethylene oxide and / or propylene oxide having a hydroxyl value of 300. Those having a low molar addition within the above range can be mentioned.

On the other hand, among the high molecular weight polyols (h2), the polyoxyalkylene polyol (h2-1) has been described in the section of the low molecular weight polyol (h1) (h2).
Examples include compounds obtained by adding an alkylene oxide to the compounds of 1-1) to (h1-5), low molecular amines, polyhydric phenols, and the like. Examples of the low molecular amines include low molecular polyamines such as ethylenediamine, tetramethylenediamine, and hexamethylenediamine, and low molecular monoamines such as nbutylamine and stearylamine. Examples of polyhydric phenols include hydroquinone, bisphenol A, bisphenol F, bisphenol S, and the like.

Examples of the alkylene oxide to be added include alkylene oxides having 2 to 4 carbon atoms, for example, ethylene oxide, propylene oxide, butylene oxide and a combination thereof (in the case of a combination, block or random addition). Specific examples of the polyoxyalkylene polyol (h2-1) include polyoxypropylene glycol, polyoxypropylene triol, polyoxyethylene polyoxypropylene glycol, polyoxyethylene polyoxypropylene triol, polyoxypropylene tetraol, and polyoxytetraol. Methylene glycol and the like.

[0051] Examples of the polyester polyol (h2-2) include the following (h2-21) to (h2-23)
Is mentioned. (H2-21) polylactone polyol (h2-23) ethylene carbonate obtained by ring-opening polymerization of condensed polyester polyol (h2-22) lactone obtained by reacting difunctional or higher polyhydric alcohol with dicarboxylic acid; Examples of the dicarboxylic acids constituting the polycarbonate polyol and the condensed polyester polyol (h2-21) obtained by the reaction of 1,6 hexanediol include: aliphatic dicarboxylic acids (succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid) Acids, maleic acid, fumaric acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.), anhydrides of these dicarboxylic acids, lower alkyl (1 to 4 carbon atoms) esters or acid halides (acid chlorides, etc.) And mixtures of two or more of these That. Polylactone polyol (h2
Examples of the lactone used in -22) include ε-caprolactone.

Specific examples of these polyester polyols (h2-2) include polyethylene adipate, polybutylene adipate, polyhexamethylene adipate,
Polyneopentyl adipate, polyethylene polypropylene adipate, polyethylene butylene adipate, polybutylene hexamethylene adipate, polydiethylene adipate, poly (polytetramethylene ether) adipate, polyethylene azelate, polyethylene sebacate, polybutylene azelate, polybutylene sebacate , Polyethylene terephthalate, polycaprolactone diol, polycarbonate diol and the like.

Specific examples of the polyolefin polyol (h2-3) include polybutadiene polyol, hydrogenated polybutadiene polyol, and polyisoprene polyol. Specific examples of the acrylic polyol (h2-4) include a copolymer of hydroxyethyl acrylate and ethyl acrylate, and a copolymer of hydroxyethyl acrylate, ethyl acrylate and styrene. The castor oil-based polyol (h2-5) includes (h
2-51) Castor oil; (h2-52) Polyester polyol of castor oil fatty acid with polyhydric alcohol or polyoxyalkylene polyol, and a mixture of two or more thereof. Specific examples of (h2-52) include mono, di or triester of castor oil fatty acid and trimethylolpropane; and mono or diester of castor oil fatty acid and polyoxypropylene glycol.

As the polymer polyol (h2-6),
Among the high molecular weight polyols exemplified as (h2-1) to (h2-5), those obtained by polymerizing ethylenically unsaturated monomers described in U.S. Pat. No. 3,383,351, such as acrylonitrile and styrene. Is mentioned. The content of the ethylenically unsaturated monomer units constituting the polymer polyol (h2-6) is usually 0.1 to 90% by weight, preferably 5.0 to 80% by weight. Polymer polyol (h2
As a production method of -6), for example, an ethylenically unsaturated monomer in a polyol is used as a polymerization initiator (radical generator, etc.)
(Eg, US Pat. No. 338)
3351).

Among the compounds exemplified above as the active hydrogen-containing compound (h), particularly preferred are ethylene oxide adducts of the polyoxyalkylene polyol (h2-1). It is preferable to use as a part of the compound (h). In this case, the active hydrogen-containing compound (h)
In terms of the content of oxyethylene units,
% By weight, especially 50 to 90% by weight. By using the ethylene oxide adduct, the dispersibility of the prepolymer (c) in forming an aqueous mixture is improved.

The low molecular weight polyol (h1) and the high molecular weight polyol (h2) may be used alone or in combination. The ratio of the low molecular weight polyol (h1) to the high molecular weight polyol (h2) is particularly limited. But, for example,
In order to enhance the effect of improving the brittleness of the foam and to enhance the effect of imparting flexibility, the weight ratio is (h
1): (h2) = (0 to 50): The usage ratio of (h2) may be increased so that (50 to 100). On the other hand,
To make the foam more rigid, (h
It is preferable to increase the usage ratio of (h1) so that 1) :( h2) = (50-100) :( 0-50).

In order to adjust the molecular weight and viscosity of the prepolymer (c), a monool (h3) may be used as a component (h) if necessary. Examples of the monol (h3) include: methanol, ethanol, and isopropanol.
, Butanol, pentanol, 2-ethylhexanol
And aliphatic monohydric alcohols such as toluene and dodecanol, and adducts of alkylphenols (octylphenol, nonylphenol, dodecylphenol, etc.) with alkylene oxides (ethylene oxide, propylene oxide, etc.). The molecular weight of the monol (h3) is usually in the same range as (h1) or (h2). The proportion of the monool (h3) optionally used in the active hydrogen compound (h) is in a range where the average number of functional groups in (h) is usually 2 or more, preferably 2.5 or more.

NC in the urethane prepolymer (c)
The O content is preferably between 0.5 and 30% by weight. Further, the properties of the urethane prepolymer (c) are preferably liquid at room temperature and have a certain degree of molecular weight and molecular composition. Its molecular weight is preferably between 1,000 and 50,000.

The urethane prepolymer (c) is, for example,
It can be produced by charging an organic polyisocyanate and an active hydrogen-containing compound in a reaction vessel and reacting at a temperature of 50 to 120 ° C. The content of the urethane prepolymer (c) unit in the foam in the present invention, that is, the content of (c) with respect to the total solid content during the production of the foam is 3 to 30% by weight, particularly 5 to 25% by weight. Preferably, there is.

The foam of the present invention may contain an inorganic filler if necessary in consideration of physical properties and cost. As inorganic fillers, cement, clay minerals, inorganic lightweight aggregates,
Inorganic fiber, fly ash, silica fume, silica powder,
Other non-water-soluble inorganic powder materials such as ceramic powder, aluminum hydroxide, alumina, and calcium sulfate can be used.
Furthermore, organic fibers can be contained to improve the tensile strength and bending strength of the foam. The amount of these additives is not particularly limited, and is usually 1800 parts by weight or less based on 100 parts by weight of phosphoric acid dispersed or in the aqueous solution (a).
Preferably, 500 parts by weight or less is appropriate.

The foam of the present invention can be foam-cured by adding a flame retardant in order to impart higher fire resistance. Preferred examples of the flame retardant include non-halogen phosphates, halogen-containing phosphates, active hydrogen-containing flame retardants, antimony trioxide, antimony pentoxide, zinc oxide and the like. These can be used in combination of two or more. The amount of the flame retardant to be used is preferably 40 parts by weight or less, particularly preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the urethane prepolymer.

In the present invention, the amount of water in the aqueous mixture containing the above-mentioned phosphoric acid dispersion or aqueous solution (a), curing agent (b), prepolymer (c) and, if necessary, blowing agent (d), It is not necessary to add more water than necessary, as long as the formation is possible, and the more water, the longer the foam and hardens, but the longer it takes to dry. The amount of water is preferably such that the solid content in the mixture is about 50 to 90% by weight.

In the present invention, for example, a catalyst can be used to control the curing rate of the prepolymer (c) forming the organic foam. Preferred examples of the catalyst include dibutyltin dilaurate, alkyl titanates, organosilicon titanates, stannas octoate, lead octylate, zinc octylate, bismuth octylate, dibutyltin diorthophenylphenoxite, tin oxide and Metal-based catalysts such as reaction products of ester compounds (eg, dioctyl phthalate), monoamines (eg, triethylamine), diamines (eg, N, N, N ′, N′-tetramethylethylenediamine), and triamines (eg, N, N, N ',
Amine catalysts such as N ", N" -pentamethyldiethylenetriamine and the like; and cyclic amines (triethylenediamine and the like). The amount of the catalyst is preferably 0.001 to 5 parts by weight based on 100 parts by weight of the prepolymer (c).

In the present invention, a foam stabilizer can be used to control the cell structure of the foam to be formed. Preferable examples of the foam stabilizer include a silicone-based surfactant, for example, "Toray Silicone"
SH-192 "," SH-193 "," SH-194 "," TFA-4200 "manufactured by Toshiba Silicone Co., Ltd." L-5320 "," L-5340 "," L-53 "manufactured by Nippon Unicar
50 "," F-121 "," F-12 "manufactured by Shin-Etsu Silicon Co., Ltd.
2 ". The amount of the foam stabilizer added is preferably 0.001 to 100 parts by weight of the urethane prepolymer.
１1 part by weight.

In the present invention, a preferred specific method for preparing the aqueous mixture and foam-hardening the same in the cells of the honeycomb is as follows. The aqueous mixture is preferably a dispersion or aqueous solution of phosphoric acids (a), a curing agent (b), a prepolymer (c), and a blowing agent (d) optionally used, the temperature of which is controlled at -20 ° C to 10 ° C. ) And inorganic fillers may be mixed and prepared at once. After mixing the prepolymer (c) with the dispersion or aqueous solution (a) of phosphoric acid adjusted to the temperature, the curing agent (b), and the foaming agent (d), if necessary, and the inorganic filler are used. They may be prepared individually or by mixing them in advance to form a slurry. In mixing the above components,
Usually, in addition to a batch mixer such as a homomixer, a continuous mixer using a static mixer or a mixing head is used, but a spiral pin described later is used in view of stability of mixing time, quantitative supply, stirring efficiency, and the like. It is particularly preferable to use a continuous high-speed stirrer such as a mixer.

The temperature of the slurry-like aqueous mixture forming the foam thus obtained is from -15 ° C to 1 ° C as described above.
The temperature can be in the range of 5 ° C. The method for filling the mixture into the cells of the honeycomb body is not particularly limited, and the mixture is spread on a belt, paper, nonwoven fabric or film in a planar manner, and after the slurry-like mixture is applied, the honeycomb material is removed. A method of filling by pressing from above, a method of pouring a slurry-like aqueous mixture into cells of a honeycomb body, a method of filling by spraying, and the like are employed.

In these methods, in any case, when the mixture is filled into a honeycomb body, it is preferable that the mixture has sufficient fluidity. In the present invention, the temperature of the mixture is adjusted to the above-mentioned value. By controlling the foaming rate in the range, the mixture can be uniformly filled.

In particular, after the above mixture is diffused in a plane,
In the method of filling the honeycomb material by pressing it from above, it is possible to more uniformly diffuse and fill the honeycomb material by using equipment for making the thickness uniform, such as a doctor blade. After filling the aqueous mixture, it is preferable that a smooth face material is brought into contact with the face of the filled honeycomb material to sufficiently fix the honeycomb material. This can prevent the foam from expanding out of the cells of the honeycomb material. Also, the mixture need not fill all cells or the entire cell. In this way, it is possible to manufacture a honeycomb core material in which a part of the cells is uniformly filled with the foam along the thickness direction of the honeycomb body.

After the above mixture is filled into the cells of the honeycomb body, it preferably foams within several seconds to several tens of minutes under normal temperature and normal pressure conditions, and then hardening is completed to form a foam. However, in winter, when the temperature is low, or when it is desired to shorten the foaming hardening time in the process, the mixture may be filled into the cells of the honeycomb body and then heated to about 30 ° C to 80 ° C. Thereafter, if necessary, the excess water may be dissipated by heating to 80C to 100C.

The honeycomb core material of the present invention produced as described above has excellent characteristics as described above, but is contained in the above-mentioned aqueous mixture, in particular, metal carbonate (b1), light metal (b3) or By controlling the amount of the foaming agent (d), its specific gravity can be adjusted to a wide range of 0.01 to 1.5. In particular, in the composite foam of the present invention, when the specific gravity is as low as 0.1 or less, the flexibility of the foam is strongly exhibited, and the obtained honeycomb core material has excellent flexibility.

Thus, in the present invention, a honeycomb core material having a composite foam of a wide range of materials from hard to soft can be obtained. Further, in the present invention, the heat insulating performance of the obtained honeycomb core material is also controlled by selecting the material of the honeycomb material and controlling the composition of the aqueous mixture, and particularly by controlling the specific gravity, for example, 0.04 kcal / m · hr · ° C. or less. In addition to providing a low thermal conductivity, a fireproof property equivalent to that of a non-combustible material can be obtained from a noncombustible material.

The surface material of the honeycomb core material in the present invention includes a metal plate, an FRP plate, a plywood, a plastic plate, a natural stone plate, and other inorganic plates. Among them, in terms of fire resistance, flame retardancy, strength, etc., metal plates such as steel plates, aluminum alloy plates, titanium alloy plates, calcium silicate plates,
Inorganic plates such as slate plates, gypsum plates and reinforced ceramics plates, and natural stone plates such as marble, granite, limestone and travertine are preferred. These face materials are subjected to painting, plating, primer, rust prevention, antibacterial and antifungal treatments as necessary.

In the case of joining the honeycomb core material and the surface material, it is possible to use an adhesive, a brazing material, or a method such as diffusion bonding. Above all, a method using an adhesive is generally used. Adhesives include thermosetting adhesives such as epoxy and vinyl phenolic, and thermoplastic adhesives such as synthetic rubber and vinyl acetate.The form is as a solution, paste, or solid. It has a shape such as a shape and a film shape. As for the selection of these adhesives,
It is appropriately selected according to the material of the surface material and the honeycomb material, the adhesive strength, the curing condition, the adhesive equipment, the durability, the price, and the like. Also,
The bonding method includes a turnback method, a pinch roller method, a hot press method, a vacuum back method, an autoclave method, and the like, and these methods can be performed alone or in combination.

[0074]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but it is needless to say that the present invention is not limited to these examples. Example 1 A 50% by weight aqueous solution of magnesium monophosphate (a-1) whose temperature was adjusted to 0 ° C. in a tank A, and a tank C which was replaced with nitrogen so as not to react with moisture in the air Room temperature TDI prepolymer (c-1) and tank B
(B-1) / (b-2) / (b-3) is a combination of basic magnesium carbonate (b-1), magnesium oxide (b-2), and aluminum hydroxide (b-3). A powder mixture was prepared so as to be / 1/3. First, (a-1) and (c-1) were taken out of each of the above tanks so that (a-1) / (c-1) became 50 parts by weight / 5 parts by weight, and a spiral pin mixer ( Immediately after mixing and agitation with a product of Taiheiyo Kiko Co., Ltd., 30 parts by weight of the above powder mixture was added by a vibrating feeder and further mixed to obtain a slurry-like mixture.

While discharging the slurry-like mixture onto a PET (polyethylene terephthalate) film on a moving belt conveyor from a discharge port of a spiral pin mixer, the mixture is sufficiently diffused using a doctor blade.
The thickness was made uniform. The temperature of the mixture at the outlet of the spiral pin mixer was 5 ° C., and the amount of the mixture applied on the PET film was 2.5 kg / m 2. At this time, since the temperature of the slurry-like mixture was controlled through the aqueous solution of monobasic magnesium phosphate, the foaming rate was reduced, and the mixture had sufficient fluidity even when the thickness of the mixture on the slurry was made uniform. Therefore, it was possible to use a doctor blade to diffuse and homogenize the liquid in a state in which there is almost no partial variation in the liquid amount.

Further, a separately prepared cell size of 20 m
m, a porosity of 95.3%, and a thickness of 40 mm, containing a magnesium silicate having a thickness of 40 mm. A flame-retardant paper honeycomb body having an ashing residue of 77% by weight in a test specified in JIS-8128 was placed above the aqueous mixture. A transparent acrylic plate was further placed from above, and was kept at room temperature while being pressed. Here, even though the aqueous mixture has a low temperature of 5 ° C., it has become possible to form a foam without delaying the time until the completion of curing. The formed foam occupies about 90% of the thickness of the honeycomb body, and the content (filling amount) of the foam in each honeycomb cell is uniform, and the cells (foam) of the foam are uniform and regular. It was. Then, by heating and drying at 90 ° C. for 2 hours,
The residual water was evaporated. The weight of the obtained honeycomb core material was 3.9 kg / m ² .

The TDI prepolymer (c-1) used in the present Example 1 and the following Examples represents the following. For 100 parts by weight of TDI-80 (manufactured by Nippon Polyurethane Co., Ltd., trade name: Coronate T-80), polyoxyethylene polyoxypropylene glycol (molecular weight: 2188, 60% by weight of ethylene oxide and 40% by weight of propylene oxide) were used. Block copolymer) 4
A prepolymer obtained by reacting 20 parts by weight. The prepolymer has an NCO content of 6.2% by weight and a number average molecular weight of 1
At 355, a viscous resin solution at room temperature.

Example 2 The temperature of the 50% by weight aqueous solution of monobasic magnesium phosphate (a-1) in tank A was adjusted to -10 ° C., and oxidized instead of magnesium oxide in the powder mixture. A slurry-like mixture was produced in exactly the same manner as in Example 1 except that calcium was used in the same ratio.

The slurry mixture was sufficiently diffused from the discharge port of the spiral pin mixer in the same manner as in Example 1 using a doctor blade to make the thickness uniform. At this time, the temperature of the mixture at the discharge port of the spiral pin mixer was -2 ° C, and the application amount of the mixture on the PET film was 2.7 kg / m ² . Also in this case, by adjusting the temperature of the aqueous solution of magnesium monophosphate in the same manner as in Example 1, the foaming rate was reduced, and the liquid thickness could be made sufficiently uniform.

Further, a separately prepared paper-like honeycomb body similar to that in Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture and kept at room temperature in a state of being pressed. In this case, it was possible to form a foam without delaying the time until the curing was completed, even though the aqueous mixture had a low temperature of -2 ° C.

The formed foam occupies about 90% of the thickness of the honeycomb body, the content (filling amount) of the foam in each honeycomb cell is uniform, and the cells (foam) of the foam are formed.
Was also uniform and well-organized. Thereafter, the residue was dried by heating at 90 ° C. for 2 hours to evaporate the residual water. The weight of the obtained honeycomb core material was 4.0 kg / m ² .

Example 3 A 50% by weight aqueous solution of magnesium monophosphate, whose temperature was adjusted to 0 ° C., in tank A, and monoethanolamine were mixed at a weight ratio of 30: 1, and phosphoric acids were mixed. A mixture of a phosphoric acid mixture (a-2) in which a part of the TDI prepolymer (c-2) was replaced with nitrogen so as not to react with the moisture in the air, and the TDI prepolymer (c-1) at room temperature in the tank C and the tank B (B-1) / (b-2) / (b-3) was mixed with basic magnesium carbonate (b-1), magnesium oxide (b-2) and aluminum hydroxide (b-3). A powder mixture mixed so as to be 1/3 was prepared. In the same manner as in Example 1, first, (a-
2) and (c-1) were taken out so that (a-2) / (c-1) became 50 parts by weight / 5 parts by weight, and immediately after mixing and stirring with a spiral pin mixer, the powder mixture was removed. By adding 30 parts by weight with a vibration feeder and further mixing, a slurry-like mixture was obtained.

The slurry-like aqueous mixture was sufficiently diffused from the discharge port of the spiral pin mixer in the same manner as in Example 1 using a doctor blade to make the thickness uniform.
At this time, the temperature of the aqueous mixture at the outlet of the spiral pin mixer was 4 ° C., and the coating amount of the slurry mixture on the PET film was 2.6 kg / m ² . On this occasion,
By adjusting the temperature of the aqueous solution of magnesium monophosphate and adding the water-soluble amine, the foaming rate of the mixture is further reduced,
It was possible to make the liquid thickness sufficiently uniform. Furthermore,
A separately prepared paper-like honeycomb body similar to that in Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture and kept at room temperature in a pressed state.
In this case, the aqueous mixture was able to form a foam without significantly delaying the time until the completion of curing, despite the low temperature of 4 ° C. and the addition of the water-soluble amine. The formed foam has a honeycomb thickness of about 80
%, And the content (filling amount) of the foam in each honeycomb cell was uniform, and the cells (foam) of the foam were uniform and regular. Thereafter, the residue was dried by heating at 90 ° C. for 2 hours to evaporate the residual water. The weight of the obtained honeycomb core material was 4.0 kg / m ² .

Example 4 A 50% by weight aqueous solution of magnesium monophosphate (a-1) in tank A whose temperature was adjusted to 0 ° C. was replaced with nitrogen so as not to react with moisture in the air. The TDI prepolymer (c-1) at room temperature in tank C and the basic magnesium carbonate (b-1) and aluminum hydroxide (b-3) in tank B were combined with (b-1) / ( A powder mixture was prepared so that b-3) was reduced to 1/2. In the same manner as in Example 1, first, (a-1) and (c-1) were converted from (a-1) / (c-
1) was taken out to 50 parts by weight / 5 parts by weight, and immediately after mixing and stirring with a spiral pin mixer, 30 parts by weight of the above powder mixture was added by a vibrating feeder and further mixed to obtain a slurry-like mixture. I got

From the discharge port of the spiral pin mixer, the slurry-like mixture was sufficiently diffused using a doctor blade in the same manner as in Example 1 to make the thickness uniform. At this time, the temperature of the aqueous mixture at the outlet of the spiral pin mixer was 5 ° C., and the coating amount was 2.7 kg / m ² . At this time, as in Example 1, the temperature of the mixture was adjusted through the aqueous solution of magnesium phosphate, and the foaming speed was reduced, and the liquid thickness was sufficiently uniform. Further, a separately prepared paper-like honeycomb body similar to that of Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture and kept at room temperature in a pressed state. The formed foam occupied about 80% of the thickness of the honeycomb, and the cells (bubbles) of the foam filled in each honeycomb cell were slightly larger than those in Examples 1 to 3. Thereafter, the residue was dried by heating at 90 ° C. for 2 hours to evaporate the residual water. The weight of the obtained honeycomb core material was 4.1 kg / m ² .

Comparative Example 1 In Example 1, 50% by weight of magnesium monophosphate was used.
Except that the temperature of the aqueous solution (a-1) was adjusted to 15 ° C., the slurry mixture was poured from the outlet of the spiral pin mixer into PET on a moving belt conveyor in the same manner as in Example 1.
The liquid was discharged while flowing on the inclined plate so that the thickness became as smooth as possible on the film. At this time, the temperature of the aqueous mixture at the outlet of the spiral pin mixer was 24 ° C., and the application amount of the slurry mixture on the PET film was 2.50 kg / m ² . At this time, since the discharged aqueous mixture has already begun to foam and has low fluidity, it has been extremely difficult to sufficiently uniform the liquid thickness using a doctor blade.

Further, a paper-like honeycomb body similar to that of Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture, and was kept at room temperature while being pressed and pressed. Here, when the honeycomb body was placed, since the foaming of the aqueous mixture had already started, some of the cells being foamed were broken by the honeycomb. The foam formed is
The honeycomb occupied about 80% of the thickness of the honeycomb, but the filling amount thereof varied slightly. Thereafter, the residue was dried by heating at 90 ° C. for 2 hours to evaporate the residual water. The weight of the obtained honeycomb core material was 4.0 kg / m ² .

Comparative Example 2 50% by weight of magnesium monophosphate in Example 4
Except that the temperature of the aqueous solution (a-1) was adjusted to 15 ° C., the slurry-like mixture was poured from the outlet of the spiral pin mixer into PET on a moving belt conveyor in the same manner as in Example 4.
The liquid was discharged while flowing on the inclined plate so that the thickness became as smooth as possible on the film. At this time, the temperature of the aqueous mixture at the outlet of the spiral pin mixer was 22 ° C., and the coating amount was 2.6 kg / m ² . At this time, since the discharged aqueous mixture has already begun to foam and has low fluidity, it has been extremely difficult to sufficiently uniform the liquid thickness using a doctor blade.

Further, a paper-like honeycomb body similar to that in Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture and kept at room temperature while being pressed. Here, when the honeycomb body was placed, since the foaming of the aqueous mixture had already started, some of the cells being foamed were broken by the honeycomb. The foam formed is
The honeycomb occupied about 80% of the thickness of the honeycomb, but the filling amount thereof varied slightly. Thereafter, the residue was dried by heating at 90 ° C. for 2 hours to evaporate the residual water. The weight of the obtained honeycomb core material was 4.0 kg / m ² .

Comparative Example 3 In Example 4, 50% by weight of magnesium phosphate monobasic
Except that the temperature of the aqueous solution (a-1) was adjusted to −25 ° C., the slurry mixture was transferred from the outlet of the spiral pin mixer to the PE on the moving belt conveyor in the same manner as in Example 1.
While discharging onto the T film, diffusion and pressure were sufficiently uniform using a doctor blade. At this time, the temperature of the aqueous mixture at the outlet of the spiral pin mixer was -17.
° C, and the coating amount was 2.6 kg / m ² . At this time, since the temperature of the discharged aqueous mixture was adjusted through the aqueous solution of magnesium phosphate, the foaming rate was reduced, and the liquid thickness could be made sufficiently uniform.

Further, a paper-like honeycomb body similar to that of Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture and kept at room temperature while being pressed. At this time, although the foaming of the aqueous mixture was delayed, the curing reaction took time, and the foam cells being formed were gradually broken, and finally, when the curing was completed, sedimentation of the foam occurred. The foam formed accounted for about 60% of the thickness of the honeycomb and the cells of the foam were non-uniform. Thereafter, by heating and drying at 90 ° C. for 2 hours, the remaining purified water was volatilized. The weight of the obtained honeycomb core material was 4.0 kg / m ² .

Comparative Example 4 A 50 wt% aqueous solution of magnesium monophosphate (a-1) whose temperature was adjusted to 0 ° C. in tank A, tank C
The basic magnesium carbonate (b-1), calcium oxide (b-2), and aluminum hydroxide (b-3) put in a mixture of (b-1) / (b-2) / (b-3) A powder mixture was prepared so as to be / 1/3. From each of the tanks, 30 parts by weight of the powder mixture was added to (a-1) 50 parts by weight using a vibrating feeder and mixed to obtain a slurry mixture.

From the discharge port of the spiral pin mixer, the slurry-like mixture was sufficiently diffused using a doctor blade in the same manner as in Example 1 to make the thickness uniform. At this time, the temperature of the aqueous mixture at the outlet of the spiral pin mixer was 5 ° C., and the coating amount was 2.7 kg / m ² .
Also in this case, by adjusting the temperature of the aqueous solution of monobasic magnesium phosphate in the same manner as in Example 1, the foaming rate of the slurry-like mixture was reduced, and the liquid thickness could be made sufficiently uniform. Further, a separately prepared paper-like honeycomb body similar to that of Example 1 was placed from above the aqueous mixture, and a transparent acrylic plate was placed from above the aqueous mixture and kept at room temperature in a pressed state.

The foam formed accounted for about 50% of the thickness of the honeycomb, and the cells of the foam were non-uniform due to collapse and sedimentation. Thereafter, the residue was dried by heating at 90 ° C. for 2 hours to evaporate the residual water. The weight of the obtained honeycomb core material was 4.0 kg / m ² .

With respect to the honeycomb core materials obtained in the above Examples and Comparative Examples, (1) foaming end time, (2) curing end time, (3) fluidity, (4) filling uniformity, (5) heat insulating property ,
(6) The falling off property of the foam and (7) the nonflammability were evaluated.
Table 1 shows the results. The evaluation methods for the above items are as follows.

(1) Time until foaming of the foamed mixture is completed. The time from when the foamed mixture was discharged from the spiral pin mixer to gradually rise and reached the upper limit in the thickness direction was visually measured. (2) Time until curing of the foamed mixture is completed. The time from when the foamed mixture was discharged from the spiral pin mixer until the foam surface became tack-free was measured by touch.

(3) Whether the doctor blade can be used. It was visually determined whether or not the slurry mixture discharged from the spiral pin mixer had fluidity and could be made uniform in thickness by a doctor blade.

(4) Uniform filling of honeycomb. The variation of the filling amount (filling height) in each cell of 500 mm × 500 mm of the honeycomb after filling was evaluated by a CV value (standard deviation / average value × 100). (5) Thermal conductivity of honeycomb core material. It was measured according to JIS-A1412.

(6) Fall-off property of the foam from the honeycomb body. 600 mm x 300 m supported at two points with a span of 500 mm
m honeycomb core material, amplitude 10mm, 100H
After vibrating at z for 3 minutes, the foam was dropped off and shifted visually. (7) Non-combustibility of the honeycomb core material. The pass / fail of the non-combustible material was evaluated by the test method of the non-combustible material specified in Notification No. 1828 of the Ministry of Construction.

[0100]

[Table 1]

[0101]

According to the production method of the present invention, since the honeycomb cell is filled with the above-mentioned inorganic and organic composite foam, the honeycomb cell has a flame-retardant and non-flammable property which cannot be obtained by a conventional organic foam. Excellent and flexible and resilient which cannot be selected with conventional inorganic foams, and the content of the composite foam in each honeycomb cell is uniform and uniform, and therefore, a sandwich structure formed from the honeycomb core material A honeycomb core material having no unevenness in heat insulation, sound insulation, rigidity, etc., and uniform performance can be obtained.

In addition, since the honeycomb and the filler have extremely large adhesiveness, the filler does not fall off from the honeycomb body, and is easily transported and handled. In addition, since the foam has flexibility and can be deformed after production, a honeycomb core material that has a good attachment of a flat surface material and is suitable for a structure having a curved surface is provided.

Further, in the cells of the honeycomb body, an aqueous mixture containing a dispersion or aqueous solution of phosphoric acid, a curing agent foaming agent and a urethane polymer having an NCO group is foamed and cured substantially simultaneously to form the inorganic foam and the organic foam. Forming a composite foam with a foam simultaneously, and suppressing foam hardening in filling the cells of the honeycomb body with the aqueous mixture, there is no variation in the content of the foam in each cell of the honeycomb body, and evenly A method for manufacturing a formed honeycomb core material is provided.

[0104]

[Brief description of the drawings]

FIG. 1 shows perspective views of some typical examples of a honeycomb body used for a honeycomb core material of the present invention. Each of these cells has the following shape. (1): hexagonal shape,
(2): circular shape, (3): cardboard shape, (4): rib shape, (5): origami shape.

[Explanation of symbols]

 f Cell size g Thickness

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B32B 27/40 B32B 27/40 E04C 2/36 E04C 2/36 A (72) Inventor Koichi Chino Chiyoda, Tokyo 3-6, Kanda Kaji-cho, Ward 3 Asahi Fiber Glass Co., Ltd. F-term (reference) 2E162 CB01 CB02 CB07 CD01 4F100 AA04 AA04B AA04H AA08 AA08H AA17 AA17H AA18B AA18H AA19 AA19H AB01B AH03B AK51BAT00 BA02BAT00B00 DC04B DD12B DG10 DG10B DJ01 EJ02B EJ08B GB07 GB08 GB31 GB33 JH01 JJ02 JJ07 JJ07B JK01 YY00B

Claims (6)

[Claims] 1. A cell size specified in JIS-A6931 of 3 to 100 mm and a porosity of 92 to 100 mm.
A mixture containing a dispersion or aqueous solution of phosphoric acid (a), a curing agent (b), a urethane prepolymer having an NCO group (c), and, if necessary, a foaming agent (d) in a honeycomb body cell having 99.5%. And filling the foam while maintaining the temperature at −15 to + 15 ° C., and foaming and curing the honeycomb core material for a sandwich structure. 2. The dispersion or aqueous solution (a) of the phosphoric acid is
2. The mixture is obtained by maintaining the temperature at 20 to +10 [deg.] C. and mixing the curing agent (b), the urethane prepolymer having an NCO group (c) and, if necessary, the blowing agent (d). Manufacturing method. 3. The material of said honeycomb body is metal or JIS.
-4 ash residues in the test specified in P8128
The production method according to claim 1, which is a flame-retardant paper of 0% or more. 4. The method according to claim 1, wherein the curing agent (b) contains at least an alkaline earth metal oxide and / or an alkaline earth metal hydroxide. 5. The phosphoric acid dispersion or aqueous solution (a) comprises:
The production method according to any one of claims 1 to 4, wherein the production method is a mixed aqueous solution comprising an acidic phosphate and a water-soluble amine. 6. A sandwich structure in which a surface material is sandwiched on both surfaces of a honeycomb core material produced by one of the methods according to claim 1. Description: