CH634255A5 - Non-combustible composite insulating material - Google Patents

Description

The invention relates to non-combustible composite insulation materials, consisting of a core layer A with low density and cover layers B applied on both sides with high density and high mechanical strength. The heat-insulating core layer contains light inorganic particles that are bonded together by high-temperature-resistant organic binders.

In the construction industry there is a need for insulation materials that should not be flammable according to DIN 4102. In addition, they should have good mechanical strengths, in particular high compressive and bending strengths, but also good edge stability and abrasion resistance.

Insulating materials made of inorganic light particles such as perlite and vermiculite are known. Both inorganic binders, such as cement, clay or lime, and organic binders, such as bitumen, starch or acrylic polymers, are used to bond the particles. Temperature-resistant, highly polymeric binders with a long-term use temperature according to DIN 53 446 of more than 100 ° C, such as z. B. are described in German patent application P 2 630 834.

Insulating materials with inorganic binders are characterized by favorable fire properties; However, their densities are generally so high that they do not have a great effect as thermal insulation materials due to their high coefficient of thermal conductivity. If the amount of binder is reduced, lower densities are obtained, but the mechanical strength then decreases very sharply. When using organic binders that have a long-term use temperature lower than 100 ° C, there is the disadvantage that when testing in a fire pit according to DIN 4102, sheet 1 (3rd version from February 1970), paragraphs 3.2 and 4.1, there is an undestroyed remaining length of much less than 35 cm remains. When using organic binders that have a continuous use temperature of over 100 ° C, a building material classification A 2 according to DIN 4102 is obtained, but the desired mechanical strengths are not achieved.

It has now been found that both goals, namely good thermal insulation and non-combustibility on the one hand and high mechanical strength on the other hand, can be achieved if a core layer according to DE-OS 2 630 834, which is responsible for good thermal insulation and non-combustibility, combined on both sides with cover layers, which give the insulation material the necessary me-6o mechanical level.

The invention relates to a composite insulation material comprising a core layer A and two outer layers B, the layers having the following composition:

65 A. Core layer:

99 to 60% by weight of inorganic light particles A1 with an average particle diameter between 0.05 and 3 mm and a bulk density between 30 and 150 kg / m3.

0 to 39% by weight of fibrous or granular inorganic additives A2,

whereby the particles are interconnected by

1 to 30% by weight of a temperature-resistant organic high molecular binder A3 with a continuous use temperature according to DIN 53 446 of more than 100 ° C,

B. Cover layers:

30 to 90% by weight of a flat carrier material B! made of interconnected inorganic or organic fibers or wires.

0 to 60 wt .-% of a fine-grained, water-insoluble mineral filler B2 with a grain size of 1 to 200 (im and a bulk density of greater than 1 g / cm3, and

3 to 30 wt .-% of a temperature-resistant organic high molecular binder B3, with a continuous use temperature according to DIN 53 446 of more than 100 ° C.

The finished composite insulation material preferably has a thickness of 10 to 100 mm, in particular 10 to 60 mm, the cover layers being 0.5 to 5, in particular 0.5 to 2 mm thick. The core preferably has a density of 70 to 300 kg / m3, the top layers of 600 to 2000 kg / m3.

The inorganic light particles Ax have an average particle diameter between 0.05 and 3 mm, preferably between 0.2 and 2 mm. Their bulk density is between 30 and 150, preferably between 40 and 100 kg / m3. Silicate materials are preferably used, such as water-insoluble alkali silicates with an SiO 2: Me20 ratio of greater than 4.5: 1 or silicates of the 2nd and 3rd main group of the periodic table. Expanded pearlite or vermiculite are particularly preferred; However, expanded foam glass, fly ash or expanded plaster are also suitable.

The core layer can optionally contain up to 39% by weight of fibrous or granular inorganic additives A2. Fibrous additives improve the elastic modulus of the building materials. The fibers should generally have a length of 2 mm to 5 cm, preferably 2 mm to 3 cm. Glass fibers which are used in amounts of 2 to 10% by weight and rock or mineral wool which are used in amounts of 5 to 30% by weight, based in each case on the total mixture, are preferred. Granular additives improve the strength of the building materials. The grains should generally have a diameter of 1 to 100 µm. Talc or gypsum are preferred, which are used in amounts of 15 to 30% by weight, based on the mixture as a whole.

In the core layers, the particles Aj and A2 are connected to one another by 1 to 30, preferably 1 to 20 and in particular 2 to 10% by weight of an organic, high-polymer binder A3. In the case of non-combustible insulation materials, the upper limit of the binder concentration is determined by the additional requirement of DIN 4102, according to which the calorific value must be below 4180 J / kg. It depends on the type of binder and can easily be measured experimentally using the test specified in the DIN standard. The lower limit of the binder concentration is given by the desired level of mechanical properties. The binders are preferably polycondensates with a continuous use temperature according to DIN 53 446 of more than 100 °. The continuous use temperature is the temperature at which the substance in question can be stored in air for 25,000 hours without its properties changing noticeably.

In the production of the core layers, preferably 1 to 50, preferably 2 to 10 percent by weight, preferably aqueous, dispersions or solutions of precondensates A3 'curable to form the high polymer binder A3 are used, which optionally include conventional dispersion stabilizers, crosslinking agents, catalysts, leveling agents

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or other additives in small amounts. In principle, the binders can also be used as a dispersion or solution in organic solvents; however, separate solvent processing is then necessary, which leads to energy and environmental problems. The precondensates A3 'cure at elevated temperatures, if appropriate in the presence of crosslinking agents or crosslinking catalysts, with further condensation or crosslinking to give the highly polymeric binder A3. In principle, however, it is also possible to use dispersions or solutions of binders A3 which are already in high molecular weight.

Examples of suitable A3 binders are: polyesterimides, polyamideimides, polyimides, polyesters, polyamides, polybenzimidazoles, polyoxazoles, melamine / formaldehyde resins, urea / formaldehyde resins and phenol / formaldehyde resins, and mixtures of these.

Particularly preferred are fused polycondensates containing imide rings, i.e. Polyesterimides, polyamideimides and polyimides.

Aqueous dispersions of polyesterimides are e.g. described in DE-OS 2 210 484 and 2 351 077. There are polycondensation products of aromatic polycarboxylic acids, polyhydric alcohols and polyhydric amines. They generally contain 0.5 to 7, preferably 1 to 5 wt .-% imide nitrogen in the form of five-membered imide rings, which are fused with aromatic nuclei. The following starting materials can generally be used for their preparation:

10 equivalents of aromatic tri- or tetracarboxylic acids, their anhydrides or esters, e.g. Trimellitic acid, pyromellitic acid or their anhydrides, optionally together with aromatic dicarboxylic acids or their esters, e.g. Terephthalic acid, isophthalic acid or naphthalenedicarboxylic acid, and their lower alkyl esters;

5 to 20 equivalents of lower aliphatic diols, optionally together with trihydric or tetravalent alcohols, for example ethylene glycol, propylene glycol, butanediol, together with glycerol, trimethylolpropane or trishydroxyethyl isocyanurate;

1 to 5 equivalents of di- or triprimeric amines, for example ethylenediamine, hexamethylenediamine, benzidine, di-aminodiphenylmethane, diaminodiphenyl ketone, diaminodiphenyl ether or diaminodiphenyl sulfone, phenylene diamine, toluenediamines, xylylenediamines or melamine.

The starting materials can - preferably in the presence of solvents - either be condensed together, or one can use precondensates, e.g. B. diimide-dicarboxylic acids from 2 moles of trimellitic anhydride and 1 mole of a diprimeric aromatic amine.

The production of polyesterimides is e.g. described in German interpretations 1 445 263.1 495 100, 1 495 152 and 1 645 435, and in DE-OS 2 412 471.

In the aqueous dispersions, the polyesterimides are in particulate form with average particle diameters generally below 50, preferably below 5 .mu.m. They generally contain from 0.01 to 5, preferably 0.1 to 3,% by weight of dispersant, in particular high-polymer organic substances containing polar groups, such as. B. polyvinyl alcohol, cellulose ether, poly-vinyl pyrrolidone, polyacrylic acid, partially saponified copolymers of acrylic esters and acrylonitrile; copolymers of vinyl pyrrolidone and vinyl propionate are preferred. They also contain crosslinking catalysts in amounts of 0.5 to 5% by weight, e.g. Oxotitanates, triethanolamine titanate, titanium lactate or titanium oxalate. They can also contain leveling agents, thickeners, antithixotropic agents and neutralizing agents. When curing at

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At temperatures above 200 to 220 ° C, further condensation and crosslinking of the polyester imides occurs.

Polyamideimides are condensation products of a tricarboxylic anhydride and an aromatic diamine (DE-OS 1 520 968.1 595 797 or DE-AS 1 720 909). Aqueous dispersions of polyamideimide precondensates are e.g. described in DE-OS 2 528 251. They can be prepared by reacting 2 moles of tricarboxylic acid anhydride, preferably trimellitic acid anhydride, with 1 mole of an aromatic diamine in an aliphatic diol as solvent, esterifying the diimide dicarboxylic acids formed with the diol and then displacing it Diols through an aromatic diamine with amide formation. The precondensate obtained generally has a degree of condensation between 1 and 10, preferably between 2 and 5. It can be ground and dispersed in water.

This aqueous dispersion can also contain the usual additives, such as dispersion stabilizers and esterification catalysts. When curing at temperatures above 200 to 220 ° C, further condensation occurs with chain extension.

Polyimides are condensation products of aromatic tetracarboxylic acids or their derivatives and aromatic diamines (DE-AS 1 202 981, DE-OS 1 420 706). Aqueous solutions of polyimide precursors, the polyamic acids, can be prepared by reacting tetracarboxylic acids (preferably pyromellitic acid) with aromatic diamines in aqueous solution in the presence of ammonia and amines (DE-OS 1 720 836, GB-PS 1 176 853). When curing at temperatures above 140 to 160 ° C, further condensation to the polyimide occurs.

Crosslinked polyesters are also suitable, preferably those based on aromatic dicarboxylic acids. Aqueous dispersions or solutions can be prepared here which contain the uncrosslinked or only slightly crosslinked polyester together with polyols as crosslinking agents. When curing at temperatures above about 130 to 150 ° C, further condensation occurs with crosslinking.

Strongly crosslinked melamine / formaldehyde and phenol / formaldehyde resins are also suitable. Pre-condensates made from melamine, phenol, cresol or higher alkyl-substituted phenols with formaldehyde, which have molecular weights between approximately 200 and 1200, are used here. For further crosslinking, formaldehyde can be added as formalin or hexamethylenetetramine. When curing at temperatures above about 120 to 140 ° C, further condensation occurs with crosslinking. If conventional hardeners are added, it can also be crosslinked below 120 ° C.

Component Bi of the cover layers is a flat carrier material made of interconnected inorganic or organic fibers or wires, which preferably do not soften and do not stretch at temperatures below 150 ° C. Glass fiber nonwovens and glass fiber fabrics are particularly suitable; however, loosely laid glass fibers or grids made of fiberglass or metal wires can also be used. Cellulose compositions, e.g. Paper, is suitable. The glass fibers can be provided with the usual layers.

If necessary, fine-grained, water-insoluble mineral fillers with a grain size between 1 and 200 μm, preferably between 1 and 50 μm and a bulk density of greater than 1 g / cm3 are used as component B2 of the outer layers. Gypsum, cement, pumice powder, quartz powder or metal oxides; silicates such as talc, kaolin or mica are preferred.

As component B3, the same temperature-resistant organic high-molecular binders come into question as for component A3 of the core layer. Component B3 is preferably used in amounts of 5 to 20% by weight.

The composite insulation boards according to the invention can be produced by various methods.

In a preferred embodiment, the starting materials of the individual layers are mixed, these are pre-formed without compacting them, the pre-formed layers are placed on top of one another and then pressed using heat. In principle, however, it is also possible to prefabricate the individual layers and to glue them together, preferably non-combustible adhesives, e.g. based on water glass.

The core layer A can basically be pre-formed in two ways:

1. In a suitable embodiment, the light particles At are sprayed with a 1 to 80, preferably 2 to 20 weight percent aqueous dispersion or solution of the binder A3 or a binder precondensate A3 ', the particles being kept in motion in conventional mixing machines. It is a particular advantage of using aqueous binder systems that a particularly fine and even distribution of light particles and binder is obtained. The product is then mechanically freed from part of the water and pressed together with the cover layers in the moist state and, if necessary, hardened in the process. If the core layer is to contain fibers A2, the fibers are first slurried in water, which contains surface-active substances dissolved as conventional disintegrants, with stirring. The binder dispersions or solutions and the light particles are then added and mixed vigorously. The majority of the water is sucked off on a sheet former common in the paper industry.

2. In another embodiment, the aqueous dispersion or solution of a binder precondensate A3 'is sprayed onto the inorganic conductive particles Ar, optionally in a mixture with additives A2, and then dried at temperatures below the curing temperature of the binder. This is preferably done at 100 to 180 ° C., in particular at 110 to 160 ° C. in a fluidized bed or in other conventional mixing units. The dry mixture obtained is then pressed together with the outer layers, the binder precondensates hardening.

The cover layers B can be produced by analog methods. The carrier material Bj is preferably impregnated with a 1 to 80, preferably 40 to 75% by weight aqueous dispersion of the binder B3 or a precondensate B3 'curing to the binder B3 and, if appropriate, the filler B2, the mass is pre-dried and the cover layers thus formed are moist with the pre-formed one Core A is pressed and hardened if necessary.

The core layer A and outer layers B are pressed at temperatures above 100 ° C. or above the curing temperature of the binder precondensates A3 ′ or B3 ′, preferably at temperatures above 150 ° C., in particular between 200 and 300 ° C. at a pressure from 105 to 3 • 10® N / m2, preferably between 10s and 106 N / m2. The curing temperature differs from binder to binder. It is also not a precisely defined temperature, but a temperature range: curing takes a very long time at its lower limit, and curing takes place temporarily at the upper limit. The temperature selected in this process step therefore depends on the dwell time specified by the pressing apparatus. The pressing process

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is used in heated press units, e.g. in belt presses. It generally lasts for about 2 to 20 minutes.

The insulation materials according to the invention can be used for decoration purposes or to increase fire resistance with foils, for. B. on aluminum, laminated. 5

The parts and percentages given in the examples relate to the weight.

Example 1 A. Preparation of the core layer A polyester imide composed of terephthalic acid, glycol, trishydroxyethyl isocyanurate, trimellitic anhydride and diaminodiphenylmethane is used as the 6% strength aqueous suspension as the binder yorkensate. The suspension contains, based on solids, 3% of a copolymer of vinyl propionate and vinyl pyrrolidone and 1% of triethanolamine titanate. 95 parts of expanded perlite with an average particle diameter of 0.7 mm and a bulk density of 70 kg / m3 are sprayed with this dispersion (5 parts of solid), mixed intimately in a gravity mixer and dried at 130 ° C.

B. Production of the top layers Paper with a basis weight of approximately 150 g / m2 is glued to an aluminum foil with a thickness of 15 µm (basis weight 40 g / m2) by 30% (based on solids) of a 70% aqueous phenolic resin of the resol type from 1 kMol Phenol and 1.6 kMol formaldehyde.

C. Production of the composite insulation material The prefabricated cover layers B with the paper side are placed on the core layer A on both sides. A tabular insulating plate is produced by pressing, which is thermally heated to approx. 250 ° C, the binder crosslinking.

The insulating plate has the following properties:

Density: 220 kg / m3

Thermal conductivity: 0.058 W / m • ° K

Compressive strength: 0.75 N / mm2

Flexural strength. 1.0 N / mm2

Water absorption: 25 vol.% (24 h under water)

Example 2

10 A. Production of the core layer

94 parts of a 70% aqueous phenol resin of the resol type, which is obtained from 1 kMol phenol and 1.6 kMol formaldehyde, are used as the binder precondensate in a mixture with 6 parts of an alkylated phenol resin pre-15 condensate based on nonylphenol / formaldehyde. 17 parts of the binder mixture are intimately mixed with 83 parts of pearlite with a bulk density of 75 kg / m3 in a gravity mixer.

20 B. Production of the top layers

35 parts of a glass fleece are impregnated with a pasty mass of 35 parts of kaolin and 30 parts (solid) of the binder mixture described under A and 40% water.

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C. Production of the composite insulation material The insulation board is produced essentially analogously to example 1. Here, however, the mixture is compressed to approx. 200 kg / m3 and heated to approx. 100 ° C. by means of high frequency, the binder hardening.

Characteristics:

Thermal conductivity: 0.058 W / m • ° K

Compressive strength: 0.8 N / mm2

Flexural strength: 0.9 N / mm2

35 water absorption: approx. 1 vol.%

Claims (10)

634255 1 to 30 wt .-% of a temperature-resistant organic high molecular binder A3 with a continuous use temperature according to DIN 53 446 of more than 100 ° C. B. Cover layers: 30 to 90% by weight of a flat carrier material Bj made of interconnected inorganic or organic fibers or wires, 0 to 60% by weight of a fine-grained, water-insoluble mineral filler B2 with a grain size of 1 to 200 µm and a bulk density of greater than 1 g / cm3, and 3 to 30% by weight of a temperature-resistant organic high-molecular binder B3 with a long-term use temperature according to DIN 53 446 of more than 100 ° C. 2. Non-combustible composite insulation material according to claim 1, characterized in that the inorganic light particles A1 are expanded perlite or vermiculite. 2nd PATENT CLAIMS 1. Non-combustible composite insulation material consisting of a core layer A and two outer layers B, characterized in that the layers have the following composition: A. Core layer: 99 to 60% by weight of inorganic light particles Aj with an average particle diameter between 0.05 and 3 mm and a bulk density between 30 and 150 kg / m3, 0 to 39% by weight of fibrous or granular inorganic additives A2, whereby the particles are connected by 3. Non-combustible composite insulation material according to claim 1, characterized in that the additives A2 are glass fibers of a length between 2 mm and 5 cm, preferably between 2 mm and 3 cm. 4. Non-combustible composite insulation material according to claim 1, characterized in that the binders A3 are poly-condensates. 5. Non-combustible composite insulation material according to claim 5 1, characterized in that the binder A3 poly are esterimides and / or polyamideimides. 6. Non-combustible composite insulation material according to claim 1, characterized in that the binders A3 are highly cross-linked melamine / formaldehyde and / or phenol / formaldehyde resins. 7. Non-combustible composite insulation material according to claim 1, characterized in that the flat carrier material is glass fiber fleece or glass fiber fabric. 8. Non-combustible composite insulation material according to claim 15 1, characterized in that the mineral fillers B2 are silicates, preferably talc, kaolin or mica. 9. Non-combustible composite insulation material according to claim 1, characterized in that the binder B3 poly 20 condensates are. 10. A method for producing insulation materials according to claim 1, characterized by the following steps: the starting components Aj and optionally A2 or Bj and optionally B2 are mixed or impregnated with 1 to 25 80% by weight aqueous dispersions or solutions of the binders A3 or B3 or of precondensates A3 'or B3' which can be cured to binders A3 or B3; layers A and B are pre-formed; 30 the pre-formed layers are assembled in the layer sequence B-A-B; finally the pre-formed layers are pressed together at temperatures above 100 ° C and pressures between 10s and 3 • 106 N / m2, the preconditions 35 'A3' and B3 'hardening, if present.