DE1952954A1 - Reinforced foam products - Google Patents

Abstract

Product with foam structure is produced by spraying or impregnating a fibre fleece layer, the fibres of which are not bonded, with a substance consisting of a heat-hardening resin and a foaming agent which produces a gas on heating, placing the substance between the fibres of the fleece, and heating the whole in order to foam the resin and simultaneously harden the substance. In practice, a plurality of such layers is piled up and pressed to form a fibrous body before being subjected to heat treatment.

Description

Foam product and process for its manufacture The invention relates to a foamed product composed of an expanded fibrous nonwoven fabric and a foamed thermoset resin that completely eliminates the voids between fibers the expanded fleece fills, consists.

A method of production also falls within the scope of the invention of such a product.

As foamed products, various synthetic resin foams have hitherto been available known. For the production of such foams one uses, for example thermosetting resins. for example, a phenolic resin foam is made by one method produced, when carried out, a material generated by heating in a resol-type phenolic resin or a phenolic resin containing a curing agent, is concentrated, with a surfactant also optionally being added will. The mixture is then heated for foaming and curing. Further are foams made from urea resins.

Epoxy resins and M melamine resins produced by processes that are im Principle are similar to the method described above.

However, these thermosetting foams are poor in elasticity and are already destroyed by the action of small forces. Also own they do not have particularly pronounced mechanical strength and do not show any particularly Excellent abrasion resistance, as it is slightly powdery when the surface is rubbed Resins can be removed. iesa foams made from heat-cured resins could therefore so far only used in areas of application in which there is no particularly good mechanical strength arrived.

Furthermore, since the foam surface is not particularly decorative, had to the products are usually provided with a surface layer of paint will. Furthermore, decorative materials have been used on the surfaces applied by adhesives.

The aim of the invention is to create foamed products that suitable as construction materials. Foams have hitherto been used for such a purpose made of thermoset resins cannot be used. Through the use according to the invention A fibrous nonwoven can give such foam products the required strength be awarded.

The present invention provides a method of manufacturing a foamed product made available.

This method consists in making a layer of a fibrous Fleece, in which the fibers are not connected to one another, to a mass spray or impregnate composed of a thermosetting resin and a foaming agent consists, wherein the foaming agent generates a gas when heated, a penetration to bring about the wetness through the fiber fleece and then such a structure or a large number of such superimposed structures for a heat treatment To undergo foaming of the mass that has penetrated the fleece, taking at the same time hardening takes place. In this way, the fibrous fleece expands, with the foamed thermosetting resin completely fills the expanded spaces.

According to a particular embodiment of the invention, the above described structure placed on top of one another and forming a fibrous body pre-deformed, with a pressure sufficient for pre-deformation at a temperature below the foaming temperature and the curing temperature of the resin before Heat treatment is applied.

Another embodiment of the invention provides a cover material to be applied to one or more structures placed one on top of the other, so that after the Heat treatment of the obtained fibrous body connected to the cover material is.

The nonwovens used to carry out the invention are similar to nonwovens Materials made from natural organic fibers such as cotton and Cotton waste, Regenerated cellulose staple fibers as well Cellulose acetate fibers, synthetic fibers such as polyester fibers, Polyamide fibers and polyvinyl acetal fibers, as well as inorganic fibers, for example Glass fibers, asbestos fibers, rock wool and slag wool. The implementation of the The material similar to the fleece used in the invention must be made in such a way that that foamable thermosetting resin compositions in a simple manner between the fibers can be brought, with the fleece used during foaming together with the Needs to expand mass.

Thermosetting resins suitable for practicing the invention are phenolic resins, urea resins, melamine resins and epoxy resins. The phenolic resins can consist of either novol or resol-type resins. Such resins are made according to the invention most commonly used due to their high efficiencies. The foaming agents used are substances that are released when heated or when heated in the presence of an acid decompose to generate a gas. One can fall back on such means, how they are used for the production of conventional foams. Examples of such Foaming agents are sodium carbonate, sodium bicarbonate, ammonium carbonate, dinitrosopentamethylente ramine, azobisisobutyronitrile and benzenesulfonylhydrazine.

Curing agent used in the case of Novokol-type phenolic resins are substances that generate formaldehyde when heated, for example hexamethylenetetramine and anhydroformaldehyde aniline. In the case of resol-type phenolic resins acidic substances can be used as hardeners, but also cure these resins without using any curing agent. In case of other thermosetting Resins can be customary hardeners if necessary use. The addition of surface-active agents is also suitable for relief uniform foam formation.

The cover materials that can be used according to the invention, are for example paper, organic wipes made of cotton, regenerated cellulose fibers or other synthetic fibers, inorganic cloth materials made of glass or Asbestos fibers are made, papers made with a synthetic resin like impregnated for example a melamine resin, phenolic resin, urea resin or vinyl resin or synthetic resin-impregnated cloths.

Sheets, foils, films or laminates are also made of synthetic materials Resins, such as melamine resins, benzoguanamine resins, polyester resins, Diallyl phthalate resins, vinyl chloride resins, styrene resins or acrylic resins in question.

It is also possible to use organic film-like materials, for example Resin board. The use of metal sheets is also possible, for example the Use of sheets made of stainless steel, aluminum, iron or zinc. Further inorganic film-like materials can be used, for example Asbestos cloths and plasterboard.

In practicing the present invention, the fibers become a Fiber fleece integrated by means of a thermosetting resin foam. When heated and Foaming becomes a molded article with a desired size without application obtained from an external pressure. In practicing the present invention in practice one can fall back on different methods. For example, can a solid thermosetting resin, a foaming agent and optionally a hardening agent and a surface-active agent are mixed homogeneously, for example in a mixing roller, a "co-kneader", a ball mill or a another mixer, at a temperature below the decomposition temperature of the foaming agent and below the curing temperature of the resin. Afterward the mixture is pulverized to form a powdery resin composition. the resin composition thus formed.

scattered over a layer of a fiber fleece, the on Layer treated in this way is optionally padded, WIL in sufficient To ensure penetration of the mass into the fleece. The impregnation in the Layer can also take place during the production of the layer. Depending on the intended The intended use of the product can include one or more such layers Forming a laminate to be placed one on top of the other. The one obtained in this way Laminate is foamed and hardened by heating, either in the Form in which it is present or after a pre-deformation at a temperature below the foaming temperature of the foaming agent, preferably at one Temperature around the melting point of the resin. That way you can obtain a shaped hemmed product. In some cases they are preformed Laminates placed on top of one another, whereupon the structure formed in this way foamed and is cured, either by heating in the present form or after compressing the structure at the same temperature as at the pre-deformation is adhered to.

Optionally, a liquid or dissolved thermosetting resin condensate, a foaming agent and optionally a Hardeners as well a surfactant mixed homogeneously to form a liquid resin composition will. A layer of the fleece is then combined with the fabric formed in this way Resin mass impregnated and at atmospheric pressure or under reduced pressure as well at normal temperature or at a temperature below the foaming temperature of the foaming agent dried, after which, depending on the intended use of the product, one or more such layers to form a laminate stacked on top of each other. The structure is then foamed and hardened, namely by heating either in the present form or after a pre-deformation the structure at a temperature below the foaming temperature of the foaming agent, preferably at a temperature around the melting point of the Harz lies. In this way, a molded foamed product can be manufactured. During the heat treatment, the fleece is expanded under the pressure created by the Foaming of the resin is produced. The ones that occur between the fibers when they expand Cavities are completely filled with the foamed resin. The received foamed product therefore has a greater thickness than before the heat treatment.

In each of the above cases, the proportion is of the fibrous nonwoven to the resin composition, for example, catfish 1 to 100.

Shall the foamed product obtained in this way, for example be used as a core material for a decorative item, then the Laminate impregnated with the resin can then be deformed after being on its A decorative film impregnated with resin is applied to the surface been is. It is also possible to use a sheet of plywood or metal instead of the one with resin use impregnated decorative film. The cover material is due to the foaming pressure pressed and firmly adheres to the foam by means of the foamed resins without that the use of an adhesive is necessary. That way you can make a decorative item. However, it is not disadvantageous if necessary to apply an adhesive to the cover material beforehand. The deformed surface is free from unevenness and wrinkles and has a pleasing appearance as a cover material Various substances can be used depending on the intended purpose Intended use of the products. In the case of a plate-like product, only one side to be covered with a cover material. Furthermore, both sides can be used cover with the same or different materials.

By means of the present invention it is possible to produce foam products with excellent mechanical properties. Own these products the further advantage that they are heat and sound absorbing. Furthermore it is depending on the type of fibers used, it is possible to manufacture products that have a excellent fire resistance, mechanical strength and other properties own.

Products with surfaces made from different covering materials can can be used directly as lightweight building materials.

The foamed products produced according to the invention can be versatile be used, for example as thermal insulation materials, sound-absorbing materials, core materials or decoration materials. They are particularly suitable as construction materials to the. Manufacture of walls, ceilings and doors.

The following examples illustrate the invention without restricting it.

Example 1 Parts by weight of novolak-like phenolic resin 500 hexamethyltetramine 50 Dinitrosopentamethylenetetramine 10 Surfactant 10 (Emasole-3130, manufactured by Kao Soap Co., Ltd.) The above-mentioned ingredients are kneaded for 10 minutes in a two-roll mixer, one roll with Water is cooled and the other roller is kept at 70 ° C. The mix will then pulverized to obtain a powdery resin mass.

45 g of this powdery resin mass are evenly over a Layer of 5 g / 500 mm x 900 mm of a cotton fiber fleece scattered. Pay attention to this Treated wisely. Layers are laid one on top of the other. Then the structure placed in a mold and heated to 140 ° C over a period of 30 minutes Foaming and curing heated.

The resulting foam product is yellow and does not crumble into a powder. The product has an apparent specific gravity of 0.11 g / ccm and a Flexural strength of 23 kg / cm². So it is a light product that has excellent mechanical properties.

When performing a second test, 8 layers become one Cotton fiber fleece sprinkled with the resin mass described above and at 80 ° C under a pressure of 2 kg / cm², whereupon the structure rose to 140 ° C is heated for foaming and curing for a period of 30 minutes. In this case, a product with an apparent specific weight is obtained of 0.10 g / ccm, a flexural strength of 26 kg / cm², an impact strength (Izod) of 1.31 kg-cm / cm², a tensile strength of 14 kg / cm² and a compressive strength of 5.6 kg / cm². A comparable product without a fiber fleece has flexural strength of 8 kg / cm², an impact strength of only 0.17 kg-cm / cm² and a tensile strength of 5 kg / cm².

Example 2 parts by weight of novolak-like phenolic resin 500 hexamethyltetramine 50 Dinitrosopentamethylenetetramine 10 Surfactant 10 (Shin-Etau Silicone F-239 manufactured by Shin-Etsu-Chemical Industry Co., Ltd.) The above specified components are mixed to produce a resin composition. 500 g this resin composition are in an equal amount of methyl alcohol to form a Impregnating varnish mixed. 100 g of this impregnating varnish are used to impregnate a layer made of 10 g / 300 mm x 300 mm of a cotton fiber fleece is used. Then will the layer dried at 70 ° C. Six layers are treated in the same way and placed on top of each other. The structure is then placed in a mold and during a period of time from 30 minutes to 140 ° C for foaming and curing heated.

In this way a foamed product is obtained that is resistant to decay and an apparent specific gravity of 0.14 g / ccm and a flexural strength of 39 kg / cm².

Example 3 A layer of a 50 g / 300 mm × 300 mm rock wool fiber fleece is impregnated with 150 g of the paint according to Example 2 and dried. Four layers, that have been treated in this way are placed on top of each other, whereupon the Structure in a mold for a period of 30 minutes at 140 ° C for foaming and curing is heated. In this way a foamed product is obtained with an apparent specific gravity of 0.16 g / cc.

Example 4 parts by weight of novolak-like phenolic resin 100 hexamethylenetetramine 15 Dinitrosopentamethylenetetramine 5 Surfactant 1 The above indicated components are kneaded for 10 minutes in a two-roll mixer. One roller of this mixer is cooled with water, while the other roller is kept at 70 ° C. The mixture is used to obtain a powdery resin composition pulverized.

45 g of this powdery resin mass are evenly over a Layer of 5 g / 300 mm x 300 mm of a staple fiber fleece scattered. Afterward the layer treated in this way is shaken to prevent the mass from penetrating into the fleece to favor. Then the fleece is through a pair of heat press rolls (100 ° C) out. Four of the preformed in this way Plates are placed on top of one another, whereupon the structure remains for a period of Is heated to 120 - 150 ° C for 30 minutes for foaming and curing.

In this case, a foamed product with an apparent specific gravity of 0.03 g / ccm, a flexural strength of 3.5 kg / cm², one Impact strength of 0.6 kg-cm / cm² and a tensile strength of 2.9 kg / cm².

Example 5 An impregnating varnish is produced in such a way that 6 g of dinitrosopentamethylene tertamine and 6 grams of a surfactant, 600 grams of a 50% methyl alcohol solution a resol-like phenolic resin can be added. The one obtained in this way Impregnation varnish is used to impregnate a layer of 10 g / 300 mm × 300 mm of a cotton fiber fleece used. The layer is then dried. Seven treated this way Layers are placed on top of one another, whereupon the structure is in a mold at 140 ° V is heated for foaming and curing for a period of 30 minutes. In this way a foamed product with an apparent specificity is obtained Weight of 1.14 g / ccm and a flexural strength of 31 kg / cm².

3eisniel 6 parts by weight of powdery urea resin 350 p-toluenesulfonylhydrazide 7 surfactant 7 ammonium chloride 3.5 The above specified components are in an angel mill to form a powdery Resin mass mixed.

45 g of this powdery heart mass are evenly spread over one layer Eight scattered from 5 g / 300 mm x 300 mm cotton fiber fleece treated in this way Layers are placed on top of each other. The structure is at 50 ° C under a pressure compressed by 20 kg / cm2 and heated to 120 - 14000 for foaming and hardening. The foam product obtained has an apparent specific gravity of 0.16 g / ccm and a flexural strength of 27 kg / cm².

Example 7 6 g of p-toluenesulfonyl hydrazide, 6 g of a surfactant Means and 3 g of ammonium chloride are evenly in 700 g of a 50% aqueous Dispersed solution of a urea resin. The dispersed solution is used for impregnation of six layers each of a 10 g / 300 mm x 300 mm nonwoven cotton fiber was used. The layers are then dried. These layers are on top of each other placed, whereupon the structure is heated to 120 ¢ 14,000 for foaming and hardening. In this way a foam product with an apparent specificity is obtained Weight of 0.15 g / ccm and high flexural strength.

Example 8 parts by weight of novolak-like phonol resin 500 hexamethylene tetramine 75 Dinitrosopentamenthylenetetramine 10 Surfactant 10 The above specified components will last 10 minutes in a two-roll mixer kneaded. One roller of this mixer is cooled with water, while the other is kept at 70 ° C. The mixture is formed into a powdery resin composition pulverized.

50 g of this powdery resin mass are evenly applied to one layer from 5 g / 300 mm x 300 mm of a beaum wool fiber fleece. Eight shifts will be treated that way. The layers are then placed on top of one another, followed by the structure at 100 ° C under a pressure of 1 kg / cm² for a period of time is squeezed for 3 minutes. On one side of the one made in this way Plate-like preformed laminate is a 0.6 mm thick melamine resin decorative film applied, while the other side with a phenolic resin-impregnated paper is coated. The composite is placed in a mold and during a Heated time of 20 minutes to 140 ° C for foaming and curing. The received The foamed product has excellent thermal insulation, sound insulation as well as heat resistance.

Example 9 45 g of the powdery resin obtained in Example 8 are evenly applied to a layer of 5 g / 300 mm × 300 mm of a staple fiber fleece scattered. Eight layers treated in this way are formed to form one Laminate placed on top of one another. Both sides of the violin are 0.3 mm thick Aluminum sheets applied, whereupon the connector to 10,000 under pressure of 1 kg / cm2 is heated for a period of 3 minutes. The plate-like one The pre-formed composite is then placed in a mold and heated to 140 ° C for a period of 20 minutes Foaming and curing heated. The foam product obtained has a sandwich structure and has an aluminum surface on both sides. This material is ideal in Way as a building material.

Example 10 parts by weight of powdery resol-type phenolic resin 100 Dinitrosopentamethylenetetramine 4 Surfactant 2 Those given above Components are kneaded in a roller whereupon the mixture to obtain one powdery resin is pulverized. 50 g of this powdery resin will be sprinkled evenly on a layer of 20 g / 300 mm x 300 mm of a glass fiber fleece. Four layers treated in this way are laid one on top of the other. On one side A 1 mm thick asbestos paper is applied to the structure, while the other side is coated with a 1 mm thick decorative asbestos paper. The composite is placed in a mold and heated to 140 ° C over a period of 30 minutes heated for foaming and hardening. The foam product obtained is a refractory one Sandwich structure with good thermal insulation properties and is suitable in excellent Meadow as building material.

Example 11 Parts by weight of powdered urea resin 100 ammonium chloride 1 p-toluenesulfonyl hydrazide 2 surfactant 2 The above specified components are by means of a ball mill to obtain a powdery Resin mass mixed. 50 g of this powdery resin mass are evenly distributed a layer of 5 g / 300 mm x 300 mm of a rayon staple fiber fleece sprinkled. six Layers treated in the same way are placed on top of one another, whereupon the Structure is heated to 50 ° C under a pressure of 2.0 kg / cm².

On both sides of this plate-like pre-formed laminate polyester resin decorative panels are applied, whereupon the composite material is converted into a Formed and heated to a temperature of 130 ° C for foaming and curing will.

The foam product obtained has a very nice sandwich structure with excellent thermal insulation properties.

Example 12 6 g of dinitrosopentamethylenetetramine and 6 g of a surfactant Means to 400 g of a 50% methyl alcohol solution of a resol-like phenolic resin added to form an impregnating varnish. This impregnation varnish is used for impregnation of four layers each of a 10 g / 300 mm x 300 mm cotton fiber fleece was used. After drying at 80 ° C., these layers are used to form a laminate stacked on top of each other. Melamine resin decorative foils are placed on both sides of this structure applied, whereupon the composite material for a period of 20 minutes Foaming and curing is heated to 140 ° C. That way you get a very nice foam product with sandwich structure.

Example 13 45 g of the powdery prepared according to Example 8 Resin mass are evenly spread over a layer of 5 g / 300 mm x 300 mm of a Reiyon staple fiber fleece. Eight layers treated this way are placed on top of each other. Vinyl chloride resin decorative layers 0.1 mm thick are placed on both sides of this structure applied, whereupon the composite is compressed at 80 ° C under a pressure of 0.5 kg / cm² will. The plate-like preformed composite is then placed in a mold transferred and over a period of 30 minutes to 120 ° C for foaming and Hardening heats up. In this way, a foamed one provided with outer layers is obtained Product.

Claims (3)

Claims 1. Process for the production of a structured foam product, characterized in that a layer of a fiber fleece in which the fibers are not connected to one another, sprinkled with a compound or impregnated, those composed of a thermosetting resin and a foaming agent which when heated a gas is generated, the mass between the fibers in the barrel-like fleece is introduced and then send such a layer or a plurality of such Layers stacked on top of each other to foam the resin mass that is incorporated into the Eats penetrated fleece, as well as for the simultaneous hardening of this mass of a heat treatment be subjected. 2. The method according to claim 1, characterized in that a plurality such layers stacked on top of one another and forming a fibrous body by applying sufficient pressure at a temperature below the Schäu temperature and the curing temperature of the resin composition before the heat treatment is pre-deformed. 3. The method according to claim 1 or 2, characterized in that Covering materials on a plurality of superimposed such layers in one can be applied in such a way that after the heat treatment the obtained fibrous Body is connected to the cover materials.