GB2030516A

GB2030516A - Fireproof laminates

Info

Publication number: GB2030516A
Application number: GB7928735A
Authority: GB
Original assignee: Bridgestone Corp
Current assignee: Bridgestone Corp
Priority date: 1978-08-18
Filing date: 1979-08-17
Publication date: 1980-04-10
Also published as: GB2030516B

Abstract

A fireproof laminate comprises a urethane modified polyisocyanurate foam as a core material (4), the foam having on one side thereof an asbestos paper (1) lined with a metal foil (3) having a thickness of less than 0.1 mm, and the foam having on the other side thereof an aluminium foil (5) having a thickness of not more than 0.1 mm, and wherein the core material has a density of 0.02-0.04 g/cm<3>, and the laminate has a total thickness of not more than 30 mm. <IMAGE>

Description

SPECIFICATION Fireproof laminates This invention relates to fireproof laminates using a urethane modified polyisocyanurate foam as a core material. More particularly, the invention relates to fireproof laminates having excellent fireproof properties and low-smoke development, which are obtained by using the above core material having a defined density and an asbestos paper lined with a metal-foil as a surface material for at least one side of the core material.

The fireproof laminate according to the invention are characterized by having Grade 2 incombustibility (quasi-incombustible material) in a test for incombustibility of internal finish materials for buildings according to Japanese Industrial Standard (JIS) A-1321. .

Recently, demands for weight-saving, ease of processability, thermal insulation and the like in building materials have been increased with the proliferation of high-rise buildings. Furthermore, flame-proofing regulations for building materials have been strengthened with the increase of danger resulting from fire.

Moreover, the use of quasi-incombustible materials is not only made necessary in given sectiorls of detached.houses, multiple dwelling houses and the like by the building regulations, but is also highly desirable in other sections.

As building materials such as ceiling materials and wall materials there have hitherto been used materials obtained by using wood or gypsum as a core material and adhering decorative paper, iron plate or other surface material to a side thereof. However, such building materials have a large specific gravity and are heavy even when used as quasi-incombustible materials, so that they have drawbacks such as poor processability, low thermal insulation, large hygroscopicity and a tendency to undergo changes in dimensional stability with time.

stately, there have been proposed building materials manufactured by using as a substrate a foamable resin for rigid polyurethane foam or polyisocyanurate foam, for example, which are advantageous in respect of thermal insulation and weight-saving, admixing or filling the foamable resin layer with a large amount of a flame retardant, a smoke-suppressing agent or inorganic granules, and laminating the foam as a core material with a relatively thick and heavy steal plate such as coloured iron plate as a surface material, a few of which are known as so-called incombustible building panels. However, it can be said that these panels are unsuitable from the point of view of weight-saving and ease of processability.On the other hand, according to JIS A-1321 "Testing method for incombustibility of internal finish materials and procedure of building" in the recently revised building regulations, laminates each composed of a core material and a surface material for use as a ceiling material or wall material are subjected to the annexed test and to a smoke test for toxicity of combustion gases under severe conditions as well as to the conventional surface test in order to examine whether or not they are of Grade 2 incombustibility (quasi-incombustible material). As a result, a restriction on the thickness of the laminate may be required even in the case of using the above mentioned panels in order for the laminate to be acceptable. Therefore, these panels can hardly be said to be suitable as building materials having a good thermal insulation.

The present inventors have made various studies with respect to the development of building materials having light-weight, good thermal insulation and being of Grade 2 incombustibility, and as a result there has previously been proposed a method of producing modified polyisocyanurate foams of Grade 2 incombustibility (U.S. Patent Application No. 917 238, Japanese Patent Application No. 35,400/77). However, the modified polyisocyanurate foams obtained by this method, while being light-weight and having excellent thermal insulation, are insufficient in respect of appearance, strength, dimensional stability and moisture absorption for direct use as building materials.

Now, the inventors have made various further studies with respect to laminates obtained by using the above modified polyisocyanurate foam as a core material, and arranging a light-weight decorative paper, a sheet or film of plastics such as vinyl chloride resin, mineral paper such as asbestos paper, or an aluminium foil as a surface material on the core material through self-adhesion of the modified polyisocyanurate foam.

However, when using the decorative paper or plastics sheet or film as the surface material, the resulting laminate is not only unacceptable as a quasi-incombustible material because the fireproof properties of the surface material are poor, but also has insufficient dimensional stability and adhesion between the core material and the surface material.On the other hand, when asbestos paper of quasi-incombustibility is used asthe surface material, if the laminate composed of the foam core and the asbestos paper is subjected to the combustion test, significant cracks are formed in the asbestos paper by the decomposition gases generated from the foam, and as a result the surface of the core material is directly exposed to a fire source to cause phenomena such as increase of fuming quantity and enlargement of lingering flame, so that the greater part of the laminates do not have Grade 2 incombustibility.Further, the asbestos paper has poor moisture resistance and flatness, so that the self-adhesion of the core material to the surface material is poqr and hence the density of the core material increases with the decrease of fluidity of the foam forming composition during the laminating and also dimensional change upon moisture absorption is large and the thermal insulation is low. Moreover, deformation of the laminate is caused due to insufficient rigidity of the asbestos paper.

Further, when using aluminium foil as the surface material, if the thickness of the foil is not less that 0.1 mm, laminates satisfying the necessary requirements as building materials can be obtained as mentioned in Japanese Patent Application No. 135,614/77, but they do not have a satisfactory appearance as an internal finish material. If the thickness of the foil is less than 0.1 mm, a flame easily passes through the surface material, so that the resulting laminate does not have Grade 2 incombustibility.

According to a first aspect of the invention, there is provided a fireproof laminate comprising a urethane modified polyisocyanurate foam as a core material, the said foam having on one side thereof an asbestos paper lined with a metal foil having a thickness of less than 0.1 mm as a front surface material for the said core material, the said asbestos paper being united with the core material through the said metal foil by self-adhesion of the foam, and the foam having on the other side thereof an aluminium foil having a thickness of not more than 0.1 mm as a back surface material for the core material, and wherein the core material has a density of 0.02-0.04 g/cm3, and the laminate has a total thickness of not more than 30 mm.

According to a second aspect of the invention, there is provided a fireproof laminate comprising a urethane modified polyisocyanurate foam as a core material, the said foam having on one side thereof an asbestos paper lined with a metal foil having a thickness of less than 0.1 mm as a front surface material for the said core material, the said asbestos paper being united with the core material through the said metal foil by self-adhesion of the foam, there being a matted or woven fibre near the interface between the core material and the said front surface material, and the foam having on the other side thereof an aluminium foil having a thickness of not more than 0.1 mm as a back surface material for the core material, and wherein the core material has a density of 0.02-0.04 g/cm3, and the laminate has a total thickness of not more than 30 mm.

According to a third aspect of the invention, there is provided a fireproof laminate comprising a urethane modified polyisocyanurate foam as a core material, the said foam having on one side thereof as a front surface material for the said core material a three-layer assembly composed of an asbestos paper as an upper layer, a matted or woven glass fibre as a middle layer and a metal foil having a thickness of less than 0.1 mm as a lower layer, the said front surface material being united with the core material through the said metal foil by self-adhesion of the foam, and the foam having on the other side thereof an aluminium foil having a thickness of not more than 0.1 mm as a back surface material for the core material, and wherein the core material has a density of 0.02-0.04 g/cm3, and the laminate has a total thickness of not more than 30 mm.

According to the first and second aspects of the invention urethane modified polyisocyanurate foams having a low density and excellent thermal insulation are used as the core material, and an asbestos paper lines with a metal foil of less than 0.1 mm thickness, which is lighter in weight than the steel plates hitherto used, is used as the front surface material, whereby there can be obtained fireproof laminates useful as building materials which are very light in weight and have excellent thermal insulation, processability and appearance. Further, the rigidity of the surface material itself is improved by lining the asbestos paper with the metal foil, so that the resistance to deformation of the surface material is considerably improved.

Moreover, by uniting the surface material with the core material through the metal foil, there-are overcome phenomena such as degradation of the adhesion between the core material and the surface material, which is a serious problem when using only asbestos paper as the surface material, increase of the density of the core material accompanied by decrease of the fluidity of the foam forming composition, dimensional change of the laminate upon moisture absorption, and decrease of thermal insulation, and further combustion characteristics such as smoke development and time of lingering flame according to the JIS A-1321 combustion test are considerably improved.

In addition, by arranging a matted or woven fibre near the interface between the core material and the surface material, the occurrence of cracks on the asbestos paper can be prevented and consequently the incombustibility of the laminate surface according to the JIS A-1321 combustion test is considerably improved. As a result, there can be provided laminates having a very high levei of Grade 2 incombustibility.

According to the third aspect of the invention, there can be obtained fireproof laminates of very light-weight and having excellent thermal insulation, processability, and appearance, which are useful as building materials, by using a three-layer assembly composed of an asbestos paper as an upper layer, a matted or woven glass fibre as a middle layer and a metal foil of less than 0.1 mm thickness as a lower layer, which is lighter in weight than the steel plates hitherto used, as the front surface material to be arranged on the urethane modified polyisocyanuratefoam having a low density and an excellent thermal insulation and constituting the core material.

According to the invention, it is essential that the density of the urethane modified poiyisocyanurate foam used as the core material is within the range of 0.02-0.04 g/cm3. When the density is less than 0.02 g/cm3, the friability of the core material becomes larger and the self-adhesive property to the surface material, dimensional stability and strength lower, so that the resulting laminates cannot be put to practical use. On the other hand, when the density exceeds 0.04 g/cm3, the fuming quantity increases in the test according to JIS A-1321, so that the smoke development of the laminate cannot reach the standard value meeting Grade 2 incombustibility.

Further, the laminate according to the invention must have a total thickness of not more than 30 mm.

When the total thickness exceeds 30 mm, increase of fuming quantity and enlargement of lingering flame, for example, are caused, whereby the laminate is not of Grade 2 incombustibility according to the JIS A-1321 combustion test.

The urethane modified polyisocyanurate foam to be used as the core material is preferably produced by polymerizing and foaming an organic polyisocyanate with a polyol in the presence of a blowing agent, an isocyanate polymerization catalyst and, if necessary, a surfactant, a modifying agent and other additives.

The organic polyisocyanates to be used in the invention are organic compounds having two or more isocyanate groups in its molecule and include aliphatic polyisocyanates, aromatic polyisocyanates, and mixtures and modified substances thereof. Suitable aliphatic polyisocyanates are hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and methylcyclohexane diisocyanate.

Suitable aromatic polyisycyanates are tolylene diisocyanate (2,4- and/or 2,6-isomers), diphenylmethane diisocyanate, bitolylene diisocyanate, naphthalene diisocyanate (e.g. 1,5-naphthalene diisocyanate), triphenylmethane triisocyanate, dianisidine diisocyanate, xylylene diisocyanate, tris(isocyanate phenyl) thiophosphate, and polynuclear polyisocyanates having the following formula

wherein n is0 or an integer of 1 or more (so-called crude MDI or polymeric isocyanates) obtained by reacting a tow polycondensate of aniline and formaldehyde with phosgene or undistilled tolylene diisocyanate.

Further, prepolymers having two or more isocyanate groups, which are obtained by any conventional method, for example prepolymers having an urethane group, a biuret group, an isocyanurate group, a carbodiimide group or an oxazolidone group, may be used. These polyisocyanates may be used alone or in admixture of two or more polyisocyanates. The organic polyisocyanate is preferably an aromatic polyisocyanate, particularly a polynuclear aromatic polyisocyanate, in view of flameproofing and thermal insulation.

The polyols to be used in the invention are preferably compounds each having two or more terminal hydroxyl groups, which may be used alone or in admixture of two or more compounds. Suitable polyols are (1) polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, hexane triol, pentaerythritol, trimethylol propane, methyl glucoside, sorbitol or sucrose and/or addition products thereof with an alkylene oxide, (2) addition products of ammonia or a polyamine such as ethylene diamine, diethylene triamine or tolylene diamine with an alkylene oxide, (3) a phosphorus containing polyol such as an addition product of phosphoric acid with an alkylene oxide, (4) an addition product of a phenol such as bisphenol A with an alkylene oxide, and (5) an addition product of an intermediate having a phenolic hydroxyl group such as novolac resin or resol resin with an alkylene oxide.

The molecular weight of the potyol and the equivalent ratio of the polyol to the organic polyisocyanate are not limited, but a preferable result can be obtained by defining the molecular weight and equivalent ratio to be within the following ranges. That is, it is preferable to use a polyol having a hydroxyl equivalent of 30-2000, more preferably 50-1000, and a urethane modifying ratio of 0.05-0.5 equivalent, more preferably 0.08-0.3 equivalent, per isocyanate group of the organic polyisocyanate used in view of the fireproof property and the self-adhesive property to the surface material.When the hydroxyl equivalent is less than 30, the friability of the resulting urethane modified polyisocyanurate foam tends to be degraded, while when the hydroxyl equivalent exceeds 2000, even if the preferred urethane modifying ratio is adopted, the amount of the polyol used considerably increases and the flame-proofing is apt to be degraded. Similarly, when the above-mentioned urethane modifying ratio is outside the above defined range, the friability or flameproofing is apt to be degraded.

In the formation of the core material, there may be used any of the well-known isocyanate polymerization catalysts, typical examples of which are as follows: (1) Tertiary amino compounds, such as dialkylaminoalkyl phenols (e.g. 2,4,6-tris(dimethylaminomethyl) phenol), triethylamine, N,N ',N"-tris(dimethylaminoalkyl)-hexahydrotriazines, tetraalkylalkylene diamines, dimethylethanol amine and diazabicyclooctane or its lower alkyl substituted derivatives.

(2) Combinations of tertiary amines with cocatalysts. Suitable cocatalysts are ethyl alcohol, monosubstituted carbamic acid, esters, aldehydes, alkylene oxides, alkylene imines, ethylene carbonate and 2,3-butanedione.

(3) Tertiary alkyl phosphines.

(4) Alkali metal salts of imides, such as potassium phthalimide.

(5) Onium compounds, such as quaternary onium hydroxyl compounds of nitrogen, phosphorus, antimony or arsenic, and onium hydroxyl compounds of sulfur or selenium.

(6) Alkyl substituted ethyleneimines, 'such as N-methylethyleneimine or phenyl-N,N-ethylene urea.

(7) Metal salts of carboxylic acids, such as potassium acetate, potassium 2-ethyl hexanoate, lead 2-ethyl hexanoate, sodium benzoate, potassium naphthenate and potassium caprylate.

(8) Oxides, hydroxides, carbonates, enolic compounds and phenolic compounds of alkali metals or alkaline earth metals.

(9) Epoxy compounds.

(10) Combinations of epoxy compounds with cocatalysts. Suitable cocatalysts are tertiary amines and metal salts of aromatic secondary amines such as a sodium salt of diphenylamine.

(11) Various metal salts, such as stannous octanoate, titanium tetrabutyrate and tributyl antimony oxide.

(12) Friedel-Crafts catalysts, such as aluminium chloride and boron.trifluoride, and (13) Chelate compounds of alkali metals, such as sodium salicylaldehyde.

These catalysts may be used alone or in an admixture thereof, but an alkali metal salt of a carboxylic acid having a carbon number of 2-12 or a combination of such an alkali metal salt with a tertiary amino compound is preferably used in view of catalytic activity and compatibility with the polyol.

The amount of the isocyanate polymerization catalyst used is preferably 0.5-10% by weight of the organic polyisocyanate in view of catalytic activity.

Any blowing agent is used in the production of conventional polyurethane foams and polyisocyanurate foams may be used. For instance, the blowing agent may be carbon dioxide gas generated by adding water to the reaction mixture or supplied from an external source, nitrogen gas or a mixture theroef. However, the preferred blowing agent is a low-boiling inert solvent evaporating by heat of reaction in the foaming process.

Such a solvent is fluorinated and/or chlorinated hydrocarbon having good compatibility, typical examples of which are trichloromonofluoromethane, dichlorodifluoromethane, dichloromonofluoromethane, monoch lorodifluoromethane, dichlorotetrafluoroethane,1,1,2-trichloro-1,2,2-trifluoroethane, methylene chloride and trichloroethane. Further, benzene, toluene, pentane or hexane may be used. These blowing agents may be used alone or in admixture thereof. Among them, trichloromonofluoromethane is preferable as the blowing agent in view of the foam properties and ease of foaming.

The addition amount of the blowing agent should be controlled so as to maintain the density of the urethane modified polyisocyanurate foam as the core material within the defined range of 0.02-0.04 g/cm3.

To this end, the blowing agent is preferably used in an amount of 10-40% by weight of the foam forming composition, though the amount is somewhat dependent upon the kind of the organic polyisocyanate and polyol and upon the previously mentioned urethane modifying ratio of the polyol.

In addition to the above-mentioned ingredients, a surfactant, a modifying agent and other additives may be added, if necessary.

The surfactant may be any surfactant usually used in the production of polyurethane foams, for example an organosilicone surfactant such as an organo-polysiloxane-polyoxyalkylene copolymer or a polyalkenyl siloxane having a polyoxyalkylene side chain. Further, oxyethylated alkyl phenols, oxyethylated aliphatic alcohols and ethylene-propylene oxide block polymers are effective as surfactants. The surfactant is preferably used in an amount of 0.01-5 parts by weight per 100 parts by weight of the organic polyisocyanate.

Other additives are inorganic hollow particles, granulated refractories, fibrous materials and inorganic fillers, which are used for improving the foam properties such as hardness. Suitable inorganic fillers are mica powder, finely divided clay, asbestos, calcium carbonate, silica gel, aluminium hydroxide, calcium hydroxide, magnesium hydroxide,'gypsum and sodium silicate.

Moreover, there may be added a flame retardant usually used in the production of polyurethane foams and urethane modified isocyanurate foams, for example halogenated organic phosphorus compounds such as tris(chloropropyl) phosphate, tris(dichloropropyl) phosphate and tris(dibromopropyl) phosphate, and inorganic flame retardants such as antimony oxide.

According to the first and second aspects of the invention it is essential that an asbestos paper lined with a metal foil having a thickness of less than 0.1 mm is used as a front surface material placed on the urethane modified polyisocyanurate foam core material in view of the appearance of the resulting laminate, and that the asbestos paper is united with the core material through the metal foil.

If asbestos paper were used alone as the surface material, the resulting laminate would have serious problems in respect of the properties required for building materials as mentioned above and further would not have Grade 2 incombustibility relating to the fireproof properties. Moreover, if the front surface material were united with the core material through the asbestos paper instead of the metal foil, the appearance of the resulting laminate would be insufficient and the laminate would only exhibit substantially the same properties (including fireproof properties) as in the case of using only the asbestos paper.

The asbestos paper may be any commercially available asbestos paper. In general, these asbestos papers are obtained by bonding asbestos fibres with a binder such as pulp, starch or synthetic resin and shaping them into a paper by means of for example a press. Although there are available various asbestos papers having a thickness of not less than 0.1 mm, it is preferable to use an asbestos paper having a thickness of 0.1-0.5 mm in view of economy and weight-saving.

The metal foil for lining the asbestos paper may be any commercially available metal foil such as iron foil, copperfoil, aluminium foil or tin foil. In order to provide light-weight building materials, it is preferable to use a metal foil having a thickness of less than 0.1 mm, which is capable of developing satisfactory fireproof properties. Among the above foils, the use of iron and aluminium foils each having a thickness of less than 0.1 mm is preferable in view of weight-saving, economy, and ease of processability. The metal foil is attached to the asbestos paper with a small amount of adhesive. In this case, the amount of the adhesive used is very small, being preferably 0.002-0.003 mm thick, so that it hardly exerts any effect on the fireproof properties.As a result, there may be used many kinds of adhesives, for example polyester resins, epoxy resins and urethane resins.

In the second aspect of the invention, a matted or woven fibre is laid near the interface between the front surface material and the core material. The fibre may be an organic fibre such as nylon fibre, polyester fibre or victoria lawn, or an inorganic fibre such as asbestos fibre, gypsum fibre, Shilas fibre or glass fibre. Among these, it is preferable to use the matted or woven glass fibre or flame retardant victoria lawn. These fibres can develop a satisfactory effect at a thickness of not more than 2 mm. If the thickness is more than 2 mm, it is difficult to penetrate the foam forming composition into the fibres, so that the self-adhesion of the core material to the surface material is degraded.If it is intended to place a matted or woven fibre near the interface between the core material and the surface material to produce a laminate, the fibres spread somewhat toward the core material during the foaming of the foam forming composition, so that the thickness of the fibre layer in the laminate becomes slightly larger than the original thickness of the fibre layer.

In the third aspect of the invention, the front surface material to be placed on the urethane modified polyisocyanurate foam is a three-layer assembly composed of an asbestos layer as an upper layer, a matted or woven glass fibre as a middle layer, and a metal foil having a thickness of less than 0.1 mm as a lower layer, which assembly is united with the core material through the metal foil.

The matted or woven glass fibre can be any commercially available glass fibre, and is preferably a light-weight matted glass fibre having a thickness of not more than 0.5 mm (sold as a trade name of Surface Mat, Filament Mat orthe like). Glass fibres having a thicker thickness and a heavier weight are unfavourable in view of weight-saving and cause a problem in respect of the adhesion between the upper and lower layers.

The metal foil having a thickness of less than 0.1 mm to be used in the lower layer may be suitably aluminium foil, iron foil or copper foil. However, aluminium foil and iron foil are preferable in view of weight-saving and economy.

The front surface material is manufactured by bonding the upper, middle and lower layers one upon the other with a small amount of an adhesive. The adhesive may be suitably a polyester resin, epoxy resin or urethane resin. Moreover, the bonding of these three layers is effected under pressure, so that the thickness of the middle layer becomes slightly thinner than the original thickness.

The outer surface of the asbestos paper constituting the front surface material may be subjected to decoration such as painting or printing if necessary, but so as not to adversely affect the fireproof properties, or may be covered with a fabricated article previously painted or printed. Further, in order to improve the adhesive property between the metal foil and the core material, a primer may be used which will not adversely affect the fireproof properties.

The back surface material to be used in the invention is preferably an aluminium foil having a thickness of not more than 0.1 mm in view of economy and ease of processability. When the thickness of the foil is more than 0.1 mm, degradation of the fireproof property occurs, because of the following. That is, when the thickness of the foil exceeds 0.1 mm, the rigidity of the back surface material becomes higher, so that when the front surface material is exposed to a flame, the decomposition gases generated from the core material cannot expand toward the back surface material and hence expand toward the front surface material, whereby the front surface material is broken.Moreover, if the back surface material were not used in the manufacture of the laminate according to the invention, the dimensional stability upon moisture absorption and the thermal conductivity would be lowered, and as a result the properties of the resulting laminate as a building material would be degraded. Therefore, it is necessary to use aluminium foil having a thickness of not more than 0.1 mm as the back surface material.

The reason why the laminates according to the invention have excellent properties as building materials and develop excellent fireproof properties and low-smoke development of Grade 2 incombustibility is believed to be as follows.

That is, according to the first and second aspects of the invention, the moisture absorption of the asbestos paper can be completely shut off by using the asbestos paper lined with the metal foil, so that dimensional change of the core material upon moisture absorption and decrease of thermal insulation can be prevented, while dimensional change of the core material can also be physically prevented by the rigidity of the metal foil. Further, by uniting the metal foil with the core material, the self-adhesion of the core material to the surface material is improved considerably. Since the metal foil has a good smoothness, the fluidity of the foam forming composition used for the formation of the core material is improved and also an additional effect of making the density of the core material low is obtained.

Referring to the fireproof properties a laminate having only asbestos paper as a surface material would not have Grade 2 incombustibility in the surface test according to the JIS A-1321 combustion test because conspicuous cracks would be formed in the asbestos paper by the decomposition gases generated from the core material and hence the surface of the core material would be directly exposed to a flame to cause phenomena such as increase of fuming quantity and enlargement of lingering flame as previously mentioned.On the contrary, the laminates according to the invention are manufactured by using an asbestos paper lined with metal foil as the front surface material and uniting the asbestos paper with the core material through the metal foil, so that the laminates of the invention have an acceptable Grade 2 incombustibility in the surface test according to the JIS A-1321 combustion test because the surface of the core material is covered with the metal foil even if cracks are formed in the asbestos paper and hence the fuming quantity and the lingering flame become less.

Furthermore, when a matted or woven fibre is laid near the interface between the core material and the front surface material, decomposition gases generated from the core material emanate through the fibre toward the exterior in the surface test according to the JIS A-1321 combustion test. As a result, the deformation of the front surface material by the decomposition gases is suppressed to develop a remarkable effect of preventing the formation of cracks in the front surface material. Moreover, the surface of the core material is covered with the fibre, so that the dissipation of heat inside the core material is suppressed to exhibit better fireproof properties.On the contrary, if the matted or woven fibre were disposed along the middle portion of the core material, if the resulting laminate were subjected to the surface test according to JIS A-1321, the above-mentioned effects could not be obtained and hence satisfactory fireproof properties would not be developed.

According to the third aspect of the invention, the three-layer assembly composed of the asbestos paper as an upper layer, the matted or woven glass fibre as a middle layer and the metal foil as a lower layer is used as the front surface material, so that when the laminate is subjected to the JIS A-1321 combustion test, the glass fibre of the middle layer and the metal foil of the lower layer suppress the expansion of the surface material caused by decomposition gases generated from the urethane modified polyisocyanuratefoam of the core material and develop the effect of completely preventing the formation of cracks in the surface material, and as a result the combustion of the core material is considerably suppressed. Therefore, the resulting laminates have an acceptable Grade 2 incombustibility.

The production of the fireproof laminates according to the invention can be carried out by any well-known process. For instance, the polyol as a urethane modifying agent, the catalyst and a blowing agent are mixed with stirring by adding a foam stabilizer and other additives, if necessary, to form a homogeneous solution, to which is added the organic polyisocyanate with stirring,whereby a foam forming composition is obtained. Then, the foam forming composition is foamed in a space defined by two metal plates as a surface material so asto form a laminate of a predetermined thickness and bonded thereto through the self-adhesion of the resulting polyisocyanurate foam. Moreover, the polyisocyanurate foam may be bonded to the surface material with an adhesive without adversely affecting the fireproof properties.In the latter case, great care must be taken in the selection of the adhesive.

The fireproof laminates according to the invention have the following characteristics, which have never been provideld by the laminates of the prior art.

(a) In the first and second aspects of the invention, the asbestos paper lined with the thin metal foil is used as the front surface material and a urethane modified polyisocyanurate foam having an excellent thermal insulation is used as the core material, so that there are provided laminates having a light-weight, an excellent processability and a very high thermal insulation.

(b) In the third aspect of the invention, the front surface material is a three-layer assembly composed of the asbestos paper as an upper layer, the glass fibre as a middle layer and the metal foil of less than 0.1 mm thickness as a lower layer, so that there are also provided laminates having a light-weight, an excellent processability and a very high thermal insulation.

(c) By uniting the front surface material with the core material through the metal foil, resistance to changes with time such as dimensional change upon moisture absorption and decrease of thermal insulation are considerably improved and further the adhesion between the core material and the surface material is improved, so that the resulting laminate is sufficiently durable for long use.

(d) The density of the core material is limited to a range of 0.02-0.04 g/cm3 and the total thickness of the laminate is restricted to not more than 30 mm, whereby the laminate is of Grade 2 incombustibility according to the JIS A-1321 combustion test.

(e) Since an asbestos paper capable of being subjected to a surface treatment such as printing or painting is used as the front surface material, laminates having a rich design can be used as building materials.

(f) The cost of the front surface material is fairly cheap as compared with the coloured steel plates usually used as the surface material.

(g) A laminate having excellent fireproof properties can be provided starting from a urethane modified polyisocyanurate foam as the core material without adding additives such as a flame retardant or inorganic filler, so that the production of such laminates is advantageous in view of the storage stability of the starting material and the production process.

(h) By laying a matted or woven fibre near the interface between the core material and the surface material, the fireproof properties are further improved and also the dimensional stability is improved considerably.

The invention will be further described with reference to the following illustrative examples. In the examples, all parts and percentages are by weight, unless otherwise stated.

In the examples reference will be made to the accompanying drawings, wherein: Figures 1-3 are fragmentary sectional views of embodiments of fireproof laminates according to the invention, respectively.

Moreover, the effect of the invention is decided on the basis of whether or not the laminate is of Grade 2 incombustibility according to the JIS A-1321 combustion test. The surface test accprding to JIS A-1321 is carried out by placing a test piece with a length, width and thickness of 22 cm x 22 cm x 15-30 cm in a heating furnace and then heating a surface of the test piece for a predetermined period using gas as a sub-heat source and an electric heater as the main heat source.Thereafter, the presence and degree of crack/deformation, time of lingering flame after completion of heating, heat release value (temperature tirne area, "C x min.) calculated from the difference between the exhaust temperature curve of the test piece and a reference curve of a perlite plate as a standard material, and fuming factor calculated from maximum fuming quantity are measured to judge the fireproof properties of the test piece on the basis of acceptable standard values shown in the following Table 1.

Further, the annexed test of the laminate is carried out under the same conditions as described above, except that three holes of 2.5 cm diameter are pierced from the front of the test piece to the rear side thereof.

In this case, the evaluation of the term "crack/deformation" is omitted.

TABLE 1 Acceptable standard values of Grade 2 incom bustibility (quasi-incombustible material) according to JIS A-1321 combustion test Heat release Time of value Fuming lingering Crack/ ("C x min.) factor flame(sec.) deformation Surface not more not more not more no harmful test than 100 than 60 than 30 degree Annexed not more not more not more test than 150 than 60 than 90 Example 1, Comparative Examples 1-3 Laminates were manufactured by using urethane modified polyisocyanurate foams made from the compounding recipe of the following Table 2 as a core material.

TABLE 2 Ingredients Parts by weight Crude diphenylmethane diisocyanate 1) 100 Polypropylene glycol 2) 13.97 Solution of 20 wt.% potassium acetate in dipropylene glycol 3) 4.0 N,N',N"-tris(dimethylaminopropyl) sym-hexahydrotriazine 4) 0.5 Trichloromonofluoromethane 5) 28 Urethane modifying ratio per isocyanate group is 0.083 Note: 1) 44 V-20 (trade name) made by Sumitomo Bayer Urethane Co., Ltd.; isocyanate equivalent = 137 2) PP-2000 (trade name) made by Sanyo Kasei Kogyo Co., Ltd.; hydroxyl equivalent = 1,000 3) The solution is abbreviated as AcOK/DPG hereinafter.

4) Polywat 41 (trade name) made by Abbott Laboratories, hereinafter abbreviated as P-41.

5) The compound is abbreviated as F-il hereinafter.

The laminate including the urethane modified polyisocyanurate foam as the core material was manufactured as follows.

In an aluminium mould 40 cm long and 40 cm wide was placed a surface material having approximately the same size as that of the mould, and then the mould was heated up to about 38"C in an oven. Separately, 300 g of the crude diphenylmethane diisocyanate was weighed in a stainless beaker of 0.5 e capacity, while the ingredients other than the above diisocyanate were weighed in a polythene beaker of 1 4 capacity and thoroughly mixed to form a homogeneous solution. To this solution was added the above diisocyanate and then the resulting mixture was immediately stirred at a high speed for about 6 seconds to obtain a foam forming composition.Then, the composition was cast into the aluminium mould having the surface material therein. (In this case, two moulds were provided and the composition was sequentially cast into these two moulds.) Thereafter, an upper aluminium cover having another surface material at its inner surface was placed on the mould through a spacer of 25 mm thickness and fixed thereto by means of clamp. This assembly was heated in an oven at a temperature of about 50"C for 15 minutes to effect the curing and then the resulting laminate was taken out from the assembly. In this procedure, there were used surface materials as shown in the following Table 3.

The thus obtained laminate was examined according to JIS A-1321 combustion test to obtain a result relating to Grade 2 incombustibility as shown in Table 3.

TABLE 3(A) Comparative Example 1 Comparative Example 2 Aspaal W-3310 1) Wall paper made from vinyl Surface Front (thickness) (0.27 mm) chloride resin (0.07 mm) + material Aspaal &num;3322 2)(0.12mm) Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0281 0.0287 0.0294 0.0293 Heat release value ( Cxmin.) 30 65 36.25 161.25 JIS-A-1321 combustion Fuming factor 62 72 96 102 test Time of lingering flame (sec.) 20 15 17 34 Crack/deformation none/ - none/ middle-large middle-large Judgement unacceptable unacceptable TABLE 3(B) Cormparative Example 3 Example 1 Front (thickness) Aluminium foil (0.05 mm) Aspaal W-3310 (0.27 mm) + Surface Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0298 0.0293 0.0292 0.0299 Heat release value ( Cxmin.) 38.75 28.75 0 16.25 JIS-A-1321 combustion Fuming factor 71.7 45.0 17.1 31.5 test Time of lingering flame (sec.) 45 33 0 28 Crack/deformation none/small - none/small middle Judgement unacceptable acceptable Note: 1),2) asbestos paper of incombustible grade, made by Jujo Seishi Co., Ltd.

In the column "front surface material" of Table 3,A+B means surface material obtained by lining B to A with an adhesive so as to face B to the core material. As the adhesive, Viron (trade name, made by Toyobo Co., Ltd., polyester resin) was used in a coating thickness of about 0.002-0.003 mm.

In each example as mentioned below, the front surface material means the above.

The fireproof laminate of Example 1 comprises a front surface material obtained by lining an asbestos paper 1 with an aluminium foil 3 through an adhesive layer 2, a core material 4 of a urethane modified polyisocyanurate foam, and a back surface material 5 of an aluminium foil as shown in Figure 1.

Moreover, the fireproof properties of the laminate were evaluated by the surface and annexed tests. As apparent from the data of Table 1 the laminate using the surface material according to the invention is of Grade 2 incombustibility according to both the surface and annexed tests, while the laminates using the convention surface material are not of Grade 2 incombustibility according to both the surface and annexed tests.

Examples 2-4, Comparative Example 4 Laminates having a total thickness of about 25mm were manufactured in the same manner as described in Example 1 by using the same compounding recipe as shown in Table 2 and the same front surface material as used in Example 1, except that the amount of F-il was changed so as to change the density of the core material.

In the following Table 4 are shown the amount of F-il, density of the core material and evaluation results relating to Grade 2 incombustibility.

TABLE 4(A) Example 2 Example 3 Front (thickness) Aspaal W-3310 (0.27 mm) + Aspaal W-3310 (0.27 mm) + Surface Aluminium foil (0.015 mm) Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Amount of F-11 (PHl) 30 26 Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0257 0.0261 0.0331 0.0322 Heat release value JIS-A-1321 ( Cxmin.) 0 0 0 40 combustion test Fuming factor 1.4 28 2.1 33.3 Time of lingering flame (sec.) 0 29 10 35 Crack/deformation none/small- - none/small- middle middle Judgement acceptable acceptable TABLE 4(B) Example 4 Comparative Exmparative Example 4 Front (thickness) Aspaal W-3310 (0.27 mm) + Aspaal W-3310 (0.27 mm) + Surface Aluminum foil (0.015 mm) Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Amount of F-11 (PHl) 22 28 Calss Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0388 0.0379 0.0420 0.0418 Heat release value JIS-A-1321 ( Cxmin.) 0 42 7.5 87.5 combustion test Fuming factor 11.7 46.2 72 58.2 Time of lingering flame (sec.) 12 39 43 44 Crack/deformation none/small - none/small Judgement acceptable unacceptable Note: Total thickness of laminate-25.4-25.7 mm From the results of Table 4, it can be seen that when the density of the core material is more than 0.04 g/cm3, the resulting laminate is not of Grade 2 incombustibility due to the degradation of the fireproof properties.

Examples 5-7, Comparative Example 5 Laminates having a different total thickness were manufactured in the same manner as described in Example 1 except that the core material of urethane modified polyisocyanurate foam was made from the compounding recipe as shown in the following Table 5 and the thickness of the spacer was changed.

In the following Table 6 are shown the density of the core material, total thickness of the laminate and evaluation results relating to Grade 2 incombustibility.

TABLE 5 Ingredients Parts by weight Crude diphenylmethane diisocyanate (44V-20) 100 PP-2000 10.77 Solution of 20 wt.% potassium acetate in dipropylene glycol (AcOK/DPG) 4.0 Dipropylene glycol 3.2 2,4,64ris(dimethylaminomethyl) phenol 1) 2.0 L-5340 2) 1.0 F-li 30 Urethane modifying ratio per isocyanate group is 0.143.

Note: 1) made by Sanyo Boeki Co., Ltd.; hereinafter abbreviated as DMP-30.

2) made by Nippon Unicar Co., Ltd.; organopolysiloxane-polyoxyalkylene copolymer.

TABLE 6(A) Example 5 Example 6 Front (thickness) Aspaal W-3310 (0.27 mm) + Aspaal W-3310 (0.27 mm) + Surface Aluminium foil (0.015 mm) Aluminium foil (0.015 mm) material Back (thickness) aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Total thickness of laminate (mm) 15.8 15.4 21.6 21.4 Density of core material (g/cm3) 0.0276 0.0274 0.0268 0.0266 Heat release value JIS-A-1321 ( Cxmin.) 0 0 0 33.75 combustion test Fuming factor 6.0 22.8 6.0 34.5 Time of lingering flame (sec.) 8 24 0 7 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 6(B) Example 7 Comparative Example 5 Front (thickness) Aspaal W-3310 (0.27 mm) + Aspaal W-3310 (0.27 mm) + Surface Aluminium foil (0.015 mm) Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Total thickness of laminate (mm) 25.0 25.2 32.0 31.4 Density of core material (g/cm3) 0.0264 0.0262 0.0259 0.0260 Heat release value JIS-A-1321 ( Cxmin.) 0 31.25 12.5 41.3 combustion test Fuming factor 5.4 40.2 60.9 52.4 Time of lingering flame (sec,) 0 32 48 45 Crack/deormation non/small- - none/small- middle middle Judgement acceptable unacceptable From the results of Table 6, it can be seen that when the total thickness of the laminate exceeds 30 mm, the fireproof properties considerably deteriorate and the laminate is not of Grade 2 incombustibility.

Examples 8-11 Laminates having a total thickness of about 25 mm were manufactured in the same manner as described in Example 1 except that the amount of F-il in the compounding recipe of Example 1 was 26 parts by weight and various asbestos papers lined with aluminium foil of 0.015 mm thickness were used as the front surface material.

In the following Table 7 are shown the surface material used, density of core material and evaluation results relating to Grade 2 incombustibility. TABLE 7(A) Example 8 Example 9 Front (thickness) Aspaal W-11001) (0.35 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0311 0.0306 0.0295 0.0308 Heat release value JIS-A-1321 ( Cxmin.) 0 40 0 37.5 combustion test Fuming factor 25.3 32.4 6.9 31.5 Time of lingering flame (sec.) 23 19 0 18 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 7(B) Example 10 Example 11 Front (thickness) Aspaal M-22822) (0.2 mm) Aspaal M-2282 (0.15 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0304 0.0309 0.0301 0.0312 Heat release value JIS-A-1321 ( Cxmin.) 23.75 37.5 25.0 42 combustion test Fuming factor 51.6 33.9 49.8 37.9 Time of lingering flame (sec.) 28 25 20 22 Crack/deformation none/smali- - none/small- middle middle Judgement acceptable acceptable Note: 1),2) asbestos paper made by Jujo Seishi Co., Ltd.

Total thickness of laminate: 25.0 - 26.0 mm Examples 12-13, Comparative Example 6 Laminates having a total thickness of about 25 mm were manufactured in the same manner as described in Example 1 by using the compounding recipe of Table 5, except that the amount of F-11 was 26 parts by weight and the thickness of the aluminium foil used for lining the asbestos paper was changed.

In the following Table 8 are shown the lining material used, density of core material and evaluation results relating to Grade 2 incombustibility.

For comparison, the fireproof properties of a laminate using only Aspaal W-3310 (thickness: 0.27 mm) as the front surface material are also shown in Table 8.

TABLE 8 Example 12 Example 13 Comparative Example 6 Front asbestos paper (thickness) W-3310 (0.27 mm) W-3310 (0.27 mm) W-3310 (0.27 mm) Surface Lining material Aluminium foil Aluminium foil material (thickness) (0.007 mm) (0.05 mm) Back (thickness) Aluminium foil Aluminium foil Aluminium foil (0.05 mm) (0.05 mm) (0.05 mm) Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Density of core material (g/cm3) 0.0277 0.0275 0.0269 0.0277 0.0278 Heat release value JIS-A-1321 ( Cxmin.) 0 18.75 0 8.75 15.0 combustion not test Fuming factor 35.4 48.0 9.6 42.6 79.5 measured Time of lingering flame (sec.) 24 23 17 21 34 Crack/deformation none/ none/ none/ small - small - smallmiddie Judgement acceptable acceptable unacceptable Examples 14-16, Comparative Example 7 Laminates having a total thickness of about 25 mm were manufactured in the same manner as described in Example 1 except that the core material of urethane modified polyisocyanurate foam was made from the compounding recipe as shown in the following Table 9, the thickness of the back surface material was changed and the heating temperature of the mould was about 60"C.

In the following Table 10 are shown the front and back surface materials used, the density of the core material and evaluation results relating to Grade 2 incombustibility.

TABLE 9 Ingredients Parts by weight Crude diphenylmethane diisocyanate (44V-20) 100 PP-2000 7.57 Solution of 33 wt.% potassium acetate in diethylene glycol 1) 7.2 Diethylene glycol 8.8 2,4,6-tris(dimethylaminomethyl) phenol 0.5 L-5340 1.0 F-li 25 Urethane modifying ratio per isocyanate group is 0.254.

Note: 1) The solution is abbreviated as AcOWDEG hereinafter.

TABLE 10(A) Example 14 Example 15 Front (thickness) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.015 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0277 0.0281 0.0277 0.0277 Heat release value JIS-A-1321 ( Cxmin.) 11.25 0 0 0 combustion test Fuming factor 57.6 31.2 2.1 29.4 Time of lingering flame (sec.) 25 30 0 32 Crack/deformation none/small - none/small Judgemant acceptable acceptable TABLE 10(B) Example 16 Comparative Example 7 Front (thickness) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.1 mm) Aluminium foil (0.15 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0285 0.0282 0.0278 0.0280 Heat release value JIS-A-1321 ( Cxmin.) 0 0 23.75 1.25 combustion test Fuming facotr 55.8 37.5 48.75 33.3 Time of lingering flame (sec.) 22 20 43 21 Crack/deformation none/small - none/small Judgement acceptable unacceptable Note) Total thickness of laminate: 25.0-25.4 mm Examples 17-26 Laminates were manufactured in the same manner as described in Example 1 except that the core material of urethane modified polyisocyanurate foam was made from the compounding recipe as shown in the following Tables 11 and 12.

In Tables 11 and 12 are shown the compounding recipe of the core material, urethane modifying ratio per isocyanate group, density of core material, total thickness of laminate and evaluation results relating to Grade 2 incombustibility.

TABLE 11(A) Example 17 Example 18 Example 19 44V-20 100 44V-20 100 44V-20 100 PP-2000 13.97 PP-2000 13.97 PP-2000 13.97 AcOK/DPG 4.0 AcOK/DPG 40 AcOK/DPG 4.0 P-41 0.5 P-41 0.5 P-41 0.5 Compounding recipe SRX-274C 1) 1.0 SRX-274C 1) 1.0 F-11 26 (part by weight) F-11 26 F-11 26 (addition of silicone (addition of silicone (reduction of surfactant to the surfactant to the F-11 amountin compounding recipe compounding recipe Example 1) of Example 1) of Example 1) Urethane modifying Urethane modifying Urethane modifying ratio=0.083 ratio=0.083 ratio=0.083 Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Total thickness of laminate (mm) 23.8 23.5 19.3 19.5 19.9 20.1 Density of core JIS-A-1321 material (g/cm3) 0.0322 0.0312 0.0330 0.0325 0.0324 0.0326 combustion test Heat release value ( Cxmin.) 0 33.75 8.75 11.25 0 8.75 Fuming factor 50.1 41.4 14.4 33.0 13.8 31.5 Time of lingering flame (sec.) 27 39 22 31 15 21 Crack/deformation none/ - none/ - none/ small small small Judgement acceptable acceptable acceptable TABLE 11(B) Example 20 Example 21 44V-20 100 44V-20 100 PP-2000 7.57 PP-2000 7.57 dipropylene glycol 8.0 dipropylene glycol 8.0 AcOK/DPG 2.0 AcOK/DPG 2.0 Compounding recipe DMP-30 0.5 DMP-30 1.0 (part by weight) L-5340 1.0 L-5430 1.0 F-11 26 F-11 26 (variation of modifying (change of DMP-30 amount agent) in Example 20) urethane modifying urethane modifying fatio = 0.204 tatio = 0.204 Class Surface test Annexed test Surface test Annexed test Total thickness of laminate (mm) 24.0 24.4 24.4 24.7 Density of core JIS-A-1321 material (g/cm3) 0.0324 0.0321 0.0310 0.0319 combustion test Heat release value ( Cxmin.) 0 3.75 0 10 Fuming factor 26.7 36.3 18.0 34.2 Time of lingering flame (sec.) 7 13 20 31 Crack/deformation none/small - none/small Judgement acceptable acceptable Note: 1) made by Nippon Unicar Co., Ltd; organopolysiloxane-polyoxyalkylene copolymer Front surface material: Aspaal W-3310 (0.27 mm) + Aluminium foil (0.015 mm) Back surface material: Aluminium foil (0.05 mm) TABLE 12(A) Example 22 Example 23 Example 24 44V-20 100 44V-20 100 44V-20 100 PP-2000 10.77 00-400 1) 10.03 PP-400 10.03 dipropylene G-300 2) 2.77 G-300 2.77 glycol 4.8 AcOK/DPG 2.0 AcOK/DEG 2.44 AcOK/DEG 2.4 DMP-30 0.5 N,N-dimethyl- N,N-dimethyl Compounding recipe L-5340 1.0 ethanolamine 0.5 ethanolamine 0.5 (part by weight) F-11 30 F-11 26 SH-193 3) 1.0 F-11 26 (change of catalyst amount in the coimpounding recipe of Examples 5-7) urethane modifying urethane modifying urethane modifying ratio=0.143 ratio=0.143 raatio=0.143 Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Total thickness of laminate (mm) 20.5 20.5 24.3 24.5 23.7 24.1 Density of core JIS-A-1321 material (g/cm3) 0.0275 0.0272 0.0330 0.0327 0.0310 0.0315 combustion test Heat release value ( Cxmin.) 0 0 11.25 17.5 0 22.5 Fuming factor 8.4 29.4 23.7 39.0 21.0 44.7 Time of lingering flame (sec.) 0 26 24 35 17 30 Crack/deformation none/ - none/ - none/ small small small Judgement acceptable acceptable acceptable TABLE 12(B) Example 25 Example 26 44V-20 100 44V-20 100 PP-200 4) 11.8 PP-200 7.57 AcOK/DEG 2.4 Diethylene glycol 4.8 Compounding recipe N,N-dimethyl- AcOK/DEG 2.4 (part by weight) ethanolamine 0.5 DMP-30 0.5 SH-193 1.0 L-5340 1.0 F-11 26 fyrol-6 5) 7.70 F-11 26 urethane modifying ratio=0.2 urethane modifying ratio=0.263 Class Surface test Annexed test Surface test Annexed test Total thickness of laminate (mm) 25.0 25.1 24.6 24.2 Density of core JIS-A-1321 material (g/cm3) 0.0277 0.0282 0.0264 0.0264 combustion test Heat release value ( Cxmin.) 0 7.5 0 16.25 Fuming factor 6.6 31.8 3.3 48.9 Time of lingering flame (sec.) 10 25 0 18 Crack/deformation none/small - none/small- middle Judgement acceptable acceptable 1) made by Sanyo Kasei Kogyo Co., Ltd.; polypropylene glycol, hydroxyl equivalent = 200 2) made by Asahi Denka Kogyo Co., Ltd.; addition polyol product of glycerin with propylene oxide, hydroxyl equivalent = 100 3) made by Toray Silicone Co., Ltd.; organosiloxane-polyoxyalkylene copolymer 4) made by Sanyo Kasei Kogyo Co., Ltd.; polypropylene glycol, hydroxyl equivalent- 100 5) made by Stauffer Chemical Corp.; phosphorus containing polyol, hydroxyl equivalent = 127.5 Front surface material : Aspaal W-3310 (0.27mm) + Aluminium foil (0.015 mm) Back surface material : Aluminium foil 0.05 mm Examples 27-3 1 Laminates having a total thickness of about 20 mm were manufactured in the same manner as described in Example 1 by using the compounding recipe of Table 5, except that the front surface material of Aspaal W-3310 (0.27 mm thickness) lined with aluminium foil of 0.015 mm thickness was subjected to various surface treatments.

In the following Table 13 are shown the nature of the surface treatment, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 13(A) Example 27 Example 28 Example 29 Acrylic resin Acrylic resin Acrylic resin Surface treatment coating 1) coating coating (beige) : spraying (beige) : spraying (beige) : spraying Thickness of coating( ) 10.5 20.9 30.8 Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Density of core material (g/cm3) 0.0273 0.0279 0.0280 0.0281 0.0273 0.0281 JIS-A-1321 Heat release combustion value ( Cxmin.) 0 10 0 18.75 0 28.75 test Fuming factor 1.8 35.1 4.5 36.3 2.4 40.5 Time of lingering flame (sec.) 0 20 0 17 10 3 Crack/deformation none/small - none/small - none/small Judgement acceptable acceptable acceptable TABLE 13(B) Example 30 Example 31 Acrylic resin coating 2) (clear) Acryl-urethane resin 4) Surface treatment (spraying) + phenolic resin 3) (grainy printing) + (parinting) butyral resin 5) (printing) Thickness of coating ( ) 7.1 +3.0 6.0 + 6.2 Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0271 0.0274 0.0275 0.0267 JIS-A-1321 Heat release combustion value ( Cxmin.) 0 15.75 0 11.25 test Fuming factor 4.8 30.6 2.1 33.3 Time of lingering flame (sec.) 6 29 0 31 Crack/deformation none/small - none/small Judgement acceptable acceptable Note: 1) made by Rock Paint Corp., trade name Air Rock 2) made by Rock Paint Corp., trade name Air Rock 3) made by Toyo lnk Col, Ltd.

4) made by Dainichi Seika Col., Ltd.

5) made by Dainichi Seika Col., Ltd.

Total thickness of laminate : 20.5-21.4 mm From the results of Table 13, it can be seen that the laminates according to the invention are of Grade 2 incombustibility even when the front surface material is subjected to a surface treatment.

Examples 32-37 Laminates, wherein a matted or woven fibre was laid near the interface between the core material and the front surface material, were manufactured using the compounding recipe of Table 1 as follows: In an aluminium mould 40 cm long and 40 cm wide were placed a surface material having approximately the same size as that of the mould and a matted or woven fibre cut to the same size, and then the mould was heated up to about 38"C in an oven. Separately, 300 g of the crude diphenylmethane diisocyanate was weighed in a stainless beaker of 0.5 e capacity, while the ingredients other than the above diisocyanate were weighed in a polyethylene beaker of 1 "capacity and thoroughly mixed to form a homogeneous solution.To this solution was added the above diisocyanate and then the resulting mixture was immediately stirred at a high speed for about 6 seconds to obtain a foam forming composition. Then, the composition was cast into the aluminium mould having the surface material therein. (In this case, two moulds were provided and the composition was sequentially cast into these two moulds.) Thereafter, an upper aluminium cover having another surface material at its inner surface was placed on the mould through a spacer of 25 mm thickness and fixed thereto by means of clamp. This assembly was heated in an oven at a temperature of about 50"C for 15 minutes to effect the curing and then the resulting laminate was taken out from the assembly.

In the following Table 14 are shown the surface materials and fibre used, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 14(A) Example 32 Example 33 Front (thickness) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium Foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Matted or woven fibre Choppoed Strand Mat Roving Cloth (thickness) EMG-450 1) (0.8 mm) FWR-33 2) (0.4 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0376 0.0346 0.0314 0.0336 Heat release value JIS-A-1321 ( Cxmin.) 52.5 48.75 0 36.25 combustion test Fuming factor 9.9 52 6.3 47.4 Time of lingering flame (sec.) 20 28 24 22 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 14(B) Example 34 Example 35 Front (thickness) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Matted or woven fibre Surface Mat CFG-08 3) Surface Mat SM-3600 4) (thickness) (0.1 mm) (0.2 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0280 0.0287 0.0301 0.0288 Heat release value JIS-A-1321 ( Cxmin.) 0 35.75 0 30.25 combustion test Fuming factor 3.9 40.5 2.4 44.1 Time of lingering flame (sec.) 13 34 0 12 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 14(C) Example 36 Example 37 Front (thickness) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Matted or woven fibre Victoria lawn (flame Glass Paper F-50 5) (thickness) proof type) (0.35 mm) (0.4 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0316 0.0316 0.0361 0.0362 Heat release value JIS-A-1321 ( Cxmin.) 0 72.5 0 52.75 combustion test Fuming factor 13.5 37.5 11.7 48.3 Time of lingering 26 29 22 15 flame (sec.) Crack/deforrmation none/small - none/small Judgement acceptable acceptable Note: 1) made by Nippon Gaishi Seni Co., Ltd.

2) made by Nippon Gaishi Seni Co., Ltd.

3) made by Nippon Gaishi Seni Co., Ltd.

4) made by Nittobo Co., Ltd.

5) made by Undernach Co., Ltd.

Total thickness of laminate : 24.1 - 24.8 mm The fireproof laminate of Example 33 comprises a front surface material of an asbestos paper 1 lined with an aluminium foil 3 through an adhesive 2, a core material 4 of a urethane modified polyisocyanurate foam, a matted glass fibre 6 laid between the front surface material and the core material, and a back surface material 5 of an aluminium foil as shown in Figure 2.

From the results of Table 14, it can be seen that the laminates according to the invention are of Grade 2 incombustibility even when a matted or woven fibre is laid between the front surface material and the core material.

Examples 38-42 Laminates having a total thickness of about 20 mm were manufactured in the same manner as described in Example 33-37 except that the thickness of the spacer was changed from 25 mm to 20 mm.

In the following Table 15 are shown the surface materials and fibre used, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 15(A) Example 38 Example 39 Front (thickness) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Matted or woven fibre Roving Cloth FWR-33 Surface Mat CFG-08 Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0316 0.0336 0.0294 0.0290 Heat release value JIS-A-1321 ( Cxmin.) 18.75 43.75 43.75 31.25 combustion test Fuming factor 9.9 46.2 12.0 37.2 Time of lingering flame (sec.) 19 30 16 15 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 15(B) Example 40 Example 41 Front (thickness) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Matted or woven fibre Surface Mat SM-3600 Victoria Lawn (flameproof type) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0334 0.0328 0.0323 0.0329 Heat release value JIS-A-1321 ( Cxmin.) 0 18.75 67.5 42.5 combustion test Fuming factor 5.1 37.5 27.6 40.2 Time of lingering flame (sec.) 19 7 26 17 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 15(C) Example 42 Front (thickness) Aspaal W-3310 (0.27 mm) Surface + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Matted or woven fibre Glass Paper F-50 Class Surface test Annexed test Density of core material (g/cm3) 0.0381 0.0370 Heat release value JISA-1321 ("C x min.) 0 48.75 combustion test Fuming factor 2.1 46.2 Time of lingering flame (sec.) 17 33 Crack/deformation none/small Judgement acceptable Note: Total thickness of laminate: 18.8 - 20.6 mm Examples 43-44 Laminates having a total thickness of about 25 mm were manufactured in the same manner as described in Example 1 by using the compounding recipe of Table 5, except that the amount of F-il was 26 parts by weight and an iron foil was used as the lining material instead of the aluminium foil.

In the following Table 16 are shown the surface materials used, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 16 Example 43 Exampie 44 Front (asbestos Aspaal W-3310 (0.27 mm) Aspaal M-2282 (0.10 mm) paper, thickness) Surface material Lining material lron foil (0.035 mm) lron foil (0.035 mm) (thickness) Back (thickness Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0280 0.0282 0.0279 0.0290 Heat reiease value JIS-A-1321 ( Cxmin.) 0 12.5 0 15.25 combustion test Fuming factor 2.4 42 6.6 40 Time of lingering flame (sec.) 0 31 0 24 Crack/deformation none/small - none/small Judgement acceptable acceptable Note: Total thickness of laminate : 24.1-24.8 mm Example 45, Comparative Examples 8-9 Laminates were manufactured by using urethane modified polyisocyanurate foams made from the compounding recipe of the following Table 17 as a core material.

TABLE 17 Ingredients Parts by weight Crude diphenylmethane diisocyanate 1) 100 Polypropylene glycol 2) 10.77 Solution of 20 wt.% potassium acetate indipropylene glycol 3) 4.0 Dipropylene glycol 3.2 2,4,6-tris(dimethylaminomethyl) phenol 4) 0.5 L-5340 5) 1.0 Trichloromonofluoromethane 6) 28 Urethane modifying ratio per isocyanate group is 0.143.

Note: 1) 44V-20 (trade name) made by Sumitomo Bayer Urethane Co., Ltd.; isocyanate equivalent = 137 2) PP-2000 (trade name) made by Sanyo Kasei Kogyo Co., Ltd.; hydroxyl equivalent = 1,000 3) The solution is abbreviated as AcOK/DPG hereinafter.

4) made by Sanyo Boeki Co., Ltd.; hereinafter abbreviated as DMP-30.

5) organopolysiloxane-polyoxyalkylene copolymer, made by Nippon Unicar Co., Ltd.

6) The compound is abbreviated as F-il hereinafter.

In an aluminium mould 40 cm long and 40 cm wide was placed a surface material having approximately the same size as that of the mould and then the mould was heated up to about 30"C in an oven. Separately, 300 g of the crude diphenylmethane diisocyanate was weighed in a stainless beaker of 0.5 e capacity, while the ingredients other than the above diisocyanate were weighed in a polyethylene beaker of 1 t capacity and thoroughly mixed to form a homogeneous solution. To this solution was added the above diisocyanate and then the resulting mixture was immediately stirred at a high speed for about 6 seconds to obtain a foam forming composition. Then, the composition was cast into the aluminium mould having the material therein.

(In this case, two moulds were provided and the composition was sequentially cast into these two moulds.) Thereafter, an upper aluminium cover having another surface material at its inner surface was placed on the mould through a spacer of 25 mm thickness and fixed thereto by means of clamp. This assembly was heated in an oven at a temperature of about 50"C for 15 minutes to effect the curing and then the resulting laminate was taken out from the assembly. In this procedure, there were used surface materials as shown in the following Table 18.

The thus obtained laminate was examined according to the JIS A-1321 combustion test to obtain a result relating to Grade incombustibility as shown in Table 18.

TABLE 18 Comparative Example 8 Comparative Example 9 Example 45 Front (thickness) Aspearl W-3310 1) Aluminium foil (0.05 mm) Aspearl W-3310 (0.27 mm) Surface (0.27 mm) + Surface Mat CFG-08 2) material + Aluminium foil (0.015 mm) Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Density of core material (g/cm3) 0.0268 - 0.0286 - 0.0281 0.0288 Heat release value JIS-A-1321 ( Cxmin.) 15.0 0 0 13.75 combustion test Fuming factor 79.5 not 67.2 not 18.9 39.9 measured measured Time of lingering flame (sec.) 34 23 0 36 Crack/deformation none/small none/small none/small Judgement unacceptable unacceptable acceptable Note: 1) asbestos paper made by Jujo Seishi Co., Ltd.

2) made by Nippon Gaishi Seni Co., Ltd.; thickness: 0.1 mm *Total thickness of laminate: 25.0-25.0 mm In the column "front surface material" of Table 18, A+B+C means a surface material obtained by assembling A as an upper layer, B as a middle layer and C as a lower layer together through an adhesive. As the adhesive, Viron (trade name, made by Toyobo Co., Ltd., polyester resin) was used in a coating thickness of about 0.005-0.01 mm. In each example as mentioned below, the front surface material means the above.

The fireproof laminate of Example 45 comprises a front surface material having a three-layer structure composed of an asbestos paper 1 as an upper layer, a matted glass fibre 7 as a middle layer and an aluminium foil 3 as a lower layer, a core material 4 of urethane modified polyisocyanurate foam, and a back surface material 5 of an aluminium foil as shown in Figure 3.

Examples 46-47, Comparative Example 10 Laminates having a total thickness of about 25 mm were manufactured in the same manner as described in Example 45 by using the same compounding recipe as shown in Table 17 and the same front and back surface materials as used in Example 45, except that the amount of F-il was changed so as to change the density of the core material.

In the following Table 19 are shown the amount of F-il, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 19 Example 46 Example 47 Comparative Example 10 Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Front (thickness) + Surface Mat CFG-08 + Surface Mat CFG-08 +Surface Mat CFG-08 Surface + Aluminium + Aluminium foil + Aluminium foil material (0.015 mm) (0.015 mm) (0.015 mm) Back (thickness) Aluminium foil Aluminium foil Aluminium foil (0.05 mm) (0.05 mm) (0.05 mm) Amount of F-11 (PHl) 30 24 17 Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Density of core material (g/cm3) 0.0259 0.0252 0.0321 0.0313 0.0415 0.0421 Heat release value JIS-a-1321 ( Cxmin.) 0 0 0 15.25 0 37.5 combustion test Fuming factor 12.3 32.1 21.3 42.6 30.9 68.5 Time of lingering flame (sec.) 5 27 0 39 0 58 Crack/deformation none/small - none/small - none/small Judgement acceptable acceptable unacceptable From the results of Table 19, it can be seen that when the density of the core material is more than 0.04 g/cm3, the resulting laminate is not of Grade 2 incombustibility due to the degradation of fireproof properties.

Examples 48-49, Comparative Example 11 Laminates having a different total thickness were manufactured in the same manner as described in Example 45 except that the core material of urethane modified polyisocyanurate foam was made from the compounding recipe as shown in the following Table 20, the thickness of the spacer was changed and the heating temperature of the mould was 60"C.

In the following Table 21 are shown the density of core material, total thickness of laminate and evaluation results relating to Grade 2 incombustibility.

TABLE 20 Ingredients Parts by weight Crude diphenylmethane diisocyanate (44V-20) 100 PP-2000 7.57 Solution of 33 wt.% potassium acetate in diethylene glycol 1) 1.2 Diethylene glycol 8.8 2,4,6-tris(dimethylaminomethyl) phenol 0.5 L-5340 1.0 F-li 25 Urethane modifying ratio per isocyanate group is 0.254.

Note: 1) The solution is abbreviated as AcOK/DEG hereinafter.

TABLE 21 Example 48 Example 49 Comparative Example 11 Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Front (thickness) + Surface Mat CFG-08 + Surface Mat CFG-08 + Surface Mat CFG-08 Surface + Aluminium foil + Aluminium foil + Aluminium foil material (0.015 mm) (0.015 mm) (0.015 mm) Back (thickness) Aluminium foil Aluminium foil Aluminium foil (0.05 mm) (0.05 mm) (0.05 mm) Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Total thickness of laminate (mm) 19.9 19.7 25.2 25.2 32.7 32.9 Density of core JIS-A-1321 material (g/cm3) 0.0273 0.0278 0.0277 0.0255 0.0268 0.0270 combustion test Heat release value ( Cxmin.) 0 13.75 0 16.25 12.5 31.25 Fuming factor 2.7 34.2 2.1 37.2 35.4 65.4 Time of lingering flame (sec.) 0 22 0 29 7 44 Crack/deformation none/small - none/small - none/small Judgement acceptable acceptable unacceptable Examples 50-54 Laminates having a total thickness of about 20 mm were manufactured in the same manner as described in Example 45, except that the kinds of the asbestos paper as the upper layer, the glass fibre as the middle layer and the metal foil as the lower layer constituting the front surface material were changed, respectively and the heating temperature of the mould was 60"C.

In the following Table 22 are shown the surface materials used, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 22(A) Example 50 Example 51 Aspaal W-1100 (0.27 mm) 1) Aspaal W-3310 (0.27 mm) Front (thickness) + Surface Mat CFG-08 + Filament Mat MF-30P 2) Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.015 mm) material Back (thickness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) Class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0281 0.0283 0.0284 0.0279 Heat release value JIS-A-1321 ( Cxmin.) 0 0 0 2.5 combustion test Fuming factor 9.9 34.5 10.8 32.4 Time of lingering flame (sec.) 5 28 0 25 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 22(B) Example 52 Example 53 Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27 mm) Front (thickness) + Filament Mat MF-60P 3) + Surface Mat CFG-08 Surface + Aluminium foil (0.015 mm) + Aluminium foil (0.05 mm) material Back (thcikness) Aluminium foil (0.05 mm) Aluminium foil (0.05 mm) class Surface test Annexed test Surface test Annexed test Density of core material (g/cm3) 0.0280 0.0284 0.0277 0.0277 Heat release value JIS-A-1321 ( Cxmin.) 0 3.75 0 0 combustion test Fuming factor 1.8 39.0 2.4 28.5 Time of lingering flame (sec.) 0 12 0 31 Crack/deformation none/small - none/small Judgement acceptable acceptable TABLE 22(C) Example 54 Aspaarl W-3310 (0.27 mm) Front (thickness) + Surface Mat CFG-08 Surface + Iron foil (0.05 mm) material Back (thickness) Aluminium foil (0.05 mm) Class Surface test Annexed test Density of core material (g/cm3) 0.0289 0.0287 Heat release value JIS-A-1321 ("C x min.) 0 16.25 combustion test Fuming factor 3.3 39.6 Time of lingering flame (sec.) 0 21 Crack/deformation none/small - Judgement acceptable Note: 1) asbestos paper made by Jujo Seishi Co., Ltd.

2) made by Nittobo Co., Ltd thickness: 0.2 mm 3) made by Nittobo Co., Ltd. thickness: 0.35 mm Total thickness of laminate: 19.6 - 20.3 mm Examples 55-57 Laminates having a total thickness of about 20 mm were manufactured in the same manner as described in Example 45, except that the core material of urethane modified polyisocyanurate foam was made from the compounding recipe as shown in the following Table 23.

In Table 23 are shown the compounding recipe, urethane modifying ratio per isocyanate group, density of core material and evaluation results relating to Grade 2 incombustibility.

TABLE 23(A) Example 55 Example 56 Example 57 Aspaal W-3310 (0.27 mm) Aspaal W-3310 (0.27mm) Aspaal W-3310 (0.27mm) Front (thickness) + Surface Mat CFG-08 + Surface Mat CFG-08 + Surface Mat CFG-08 Surface + Aluminium foil + Aluminium foil + Aluminiumfoil material (0.015 mm) (0.015 mm) (0.015 mm) Back Aluminium foil Aluminium foil Aluminium foil Crude diphenyl- Crude diphenyl- Crude diphenylmethane methane methane diisocyanate diisocyanate diisocyanate (44V-20) 100 (44V-20) 100 (44V-20) 100 PP-2000 7.57 PP-2000 13.97 PP-400 2) 10.03 Compounding recipe (part by weight) AcOK/DEG 1.2 AcOK/DPG 4.0 G-300 3) 2.77 Diethylene 2,4,6-tris- AcOK/DEG 2.4 glycol 8.8 (dimethylamino N,N',N"-tris- methyl)phenol 2.0 N,N-dimethyl (dimethyl- ethanolamine 0.5 aminopropyl)- F-11 28 sym-hexahydro- SH-193 4) 1.5 triazine 1) 0.5 F-11 26 L-5340 1.0 F-11 25 Urethane modifying ratio 0.254 0.083 0.143 TABLE 23(B) Example 55 Example 56 Example 57 Class Surface Annexed Surface Annexed Surface Annexed test test test test test test Density of core material (g/cm3) 0.0270 0.0279 0.0289 0.0293 0.0307 0.0305 JIS-A-1321 combustion test Heat release value ( Cxmin.) 0 17.5 3.75 21.25 0 0 Fuming factor 18.3 34.2 21.6 37.2 4.8 41.7 Time of lingering flame (sec.) 3 20 11 19 0 35 Crack/deformation none/small - none/small - none/small Judgement acceptable acceptable acceptable Total thickness of laminate: 19.2 - 21.3 mm Note: 1) made by Abbott Laboratories, Polycat 41 (trade name) 2) made by Sanyo Kasei Kogyo Co., Ltd.; polypropylene glycol, hydroxyl equivalent=200 3) made by Asahi Denka Kogyo Co., Ltd.; addition polyol product of glycerin with propylene oxide, hydroxy equivalent=100 4) made by Toray Silicone Col., Ltd; organosiloxane-polyoxyalkylene copolymer

Claims

1. A fireproof laminate cqmprising a urethane modified polyisocyanurate foam as a core material, the said foam having on one side thereof an asbestos paper lined with a metal foil having a thickness of less than 0.1 mm as a front surface material for the said core material, the said asbestos paper being united with the core material through the said metal foil by self-adhesion of the foam, and the foam having on the other side thereof an aluminium foil having a thickness of not more than 0.1 mm as a back surface material for the core material, and wherein the core material has a density of 0.02-0.04 g/cm3, and the laminate has a total thickness of not more than 30 mm.

2. Afireproof laminate comprising a urethane modified polyisocyanurate foam as a core material, the said foam having on one side thereof an asbestos paper lined with a metal foil having a thickness of less than 0.1 mm as a front surface material for the said core material, the said asbestos paper being united with the core material through the said metal foil by self-adhesion of the foam, there being a matted or woven fibre near the interface between the core material and the said front surface material, and the foam having on the other side thereof an aluminium foil having a thickness of not more than 0.1 mm as a back surface material for the core material, and wherein the core material has a density of 0.02-0.04 g/cm3, and the laminate has a total thickness of not more than 30 mm.

3. A fireproof laminate as claimed in claim 2, wherein the said matted or woven fibre is glass fibre or victoria lawn.

4. A fireproof laminate as claimed in any of claims 1 to 3, wherein the said metal foil used for lining the said asbestos paper is an aluminium foil.

5. Afireproof laminate comprising a urethane modified polyisocyanurate foam as a core material, the said foam having on one side thereof as a front surface material for the said core material a three-layer assembly composed of an asbestos paper as an upper layer, a matted or woven glass fibre as a middle layer and a metal foil having a thickness of less than 0.1 mm as a lower layer, the said front surface material being united with the core material through the said metal foil by self-adhesion of the foam, and the foam having on the other side thereof an aluminium foil having a thickness of not more than 0.1 mm as a back surface material for the core material, and wherein the core material has a density of 0.02-0.04 g/cm3, and the laminate has a total thickness of not more than 30 mm.

6. A fireproof laminate as claimed in claim 5, wherein the said metal foil used as the lower layer of the said front surface material is an aluminium foil.

7. Afireproof laminate as claimed in any of claims 1 to 6, wherein the urethane modified polyisocyanurate foam is produced by reacting an organic polyisocyanate with a polyol having a hydroxyl equivalent of 30-2,000 in the presence of an isocyanate polymerization catalyst and a blowing agent.

8. Afireproof laminate as claimed in claim 7, wherein the polyol is used in an amount of 0.05-0.5 equivalent per isocyanate group of the organic polyisocyanate.

9. Afireproof laminate as claimed in claim 7 or 8, wherein the polyol is a compound having two or more terminal hydroxyl groups.

10. A fireproof laminate as claimed in claim 9, wherein the polyol is (1) a polyhydric alcohol and/or an addition product thereof with an alkylene oxide, (2) an addition product of ammonia or a polyamine with an alkylene oxide, (3) an addition product of phosphoric acid with an alkylene oxide, (4) an addition product of a phenol with an alkylene oxide, or (5) an addition product of an intermediate having a phenolic hydroxyl group with an alkylene oxide.

11. A fireproof laminate as claimed in claim 10, wherein the said polyhydric alcohol is ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, diethyiene glycol, dipropylene glycol, glycerin, hexane triol, pentaerythritol, trimethylol propane, methyl glucoside, sorbitol or sucrose.

12. Afireproof laminate as claimed in claim 10, wherein the said polyamine is ethylene diamine, diethylene diamine ortolylene diamine.

13. Afireproof laminate as claimed in claim 10, wherein the said intermediate having a phenolic hydroxyl group is novolac resin or resol resin.

14. Afireproof laminate as claimed in any of claims 10 to 13, wherein the said alkylene oxide is ethylene oxide or propylene oxide.

15. A fireproof laminate as claimed in any of claims 7 to 14, wherein the organic polyisocyanate is an aromatic polyisocyanate.

16. A fireproof laminate as claimed in any of claims 7 to 14, wherein the organic polyisocyanate is a mixture of polymethylene-polyphenyl isocyanates having the following formula

wherein n is O or an integer of 1 or more.

17. A fireproof laminate as claimed in any of claims 7 to 16, wherein the isocyanate polymerization catalyst is an alkali metal salt of a carboxylic acid having a carbon number of 2-12 or a combination of a said alkali metal saltwith a tertiary amino compound.

18. A fireproof laminate as claimed in claim 17, wherein the said alkali metal salt of a carboxylic acid is selected from potassium acetate, potassium 2-ethyl hexanoate, lead 2-ethyl hexanoate, sodium benzoate, potassium naphthenate and potassium caprylate.

19. A fireproof laminate as claimed in claim 17 or 18, wherein the said tertiary amino compound is selected from dialkylaminoalkyl phenols, triethylamine, N,N ',N"-tris(dimethylaminoalkyl)-hexhydrotriazines, tetraalkylalkylene diamines, dimethylethanol amine and diazabicyclooctane or its lower alkyl substituted derivatives.

20. A fireproof laminate as claimed in claim 19, wherein the said dialkylaminoalkyl phenol is 2,4,6-tris(dimethylaminomethyl) phenol.

21. A fireproof laminate as claimed in any of claims 17 to 20, wherein the isocyanate polymerization catalyst is used in an amount of 0.5-10% by weight of the organic polyisocyanate.

22. Afireproof laminate as claimed in any of claims 7 to 21, wherein the blowing agent is a low-boiling inert organic compound.

23. A fireproof laminate as claimed in claim 22, wherein the blowing agent is trichloromonofluoromethane.

24. A fireproof laminate as claimed in any of claims 7 to 23, wherein the blowing agent is used in an amount of 10-40% by weight of the foam forming composition.

25. A fireproof laminate according to claim 1, substantially as herein described in any of the foregoing Examples 1 to 57.