DE2811347A1 - NEW COMPOSED PRODUCT BASED ON FOAM AND FORMO-PHENOLIC LIGHTWEIGHT RESIN AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Description

'811347

The present invention relates to a new composite product containing a foam product _s preferably balls of polystyrene cell _s and a slightly cooked formo-phenolic resin (resine formo-phenoliaue alleged) as well as the process for producing the product.

A method has already been described for obtaining sheets or other shaped articles by molding grains or beads which can be made porous ₉ in a thermoplastic resin; during molding, the possibly preheated grains are kept at a temperature sufficient to foam and stick together so that a single, unitary article is formed.

Many years ago a process for the production of moldings was described, which is characterized in that particles of foamed or foamable polystyrene are connected by means of an adhesive or binder. More than 10 years it has as an adhesive or binder resins proposed _s thermosetting to use _s like "urea - melamine = phenol - formaldehyde resins or cresol - resorcinol resins".

However, the products obtained by these processes did not show the mechanical and insulating properties at the same time j which are desirable for numerous applications.

A new composite product has now been found ^ which has a combination of remarkable properties in comparison with known products of the same type.

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This product is characterized in that it consists of a foam in the form of starting particles which are connected to each other by an easily made formo-phenolic resin.

The particles of foams (or of lightweight materials) usable according to the invention, are spheres made of foamed polystyrene or spheres made of formo-phenol foam or glass spheres made porous or clay or balls made of stone made porous (for example of the "pearlite" type). It is preferable to use balls made of lightweight polystyrene, balls that are im have a substantially spherical shape and a diameter between approximately 0.8 and 10 mm.

It is possible to make particles of foams of various types (mixture of polystyrene and spheres made of porous Glass), and to control the properties of the final product it is advantageous to use mixtures of particles different dimensions (mean diameter) to be used.

The use of spheres of different dimensions allows the natural voids (before the resin is used) between the spheres to be reduced as much as possible. In the concrete industry, a so-called "de valette" method is known, which allows a selection of suitable grain dimensions and minimizes the amount of hydraulic binding agent that must be used to obtain a closed concrete using these grains. According to the invention, for example, a mixture of a volume part of spheres made of porous polystyrene with an average diameter of β vm alt 0 "4" / olumpartchen of spheres made of porous polystyrene with an average diameter of about 0.8 mm.

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A formo-phenolic resin with a density (densite * apparente) of 50 kg per square meter - ⁵ to 500 kg per square meter such as freon. This resole also advantageously contains a surfactant which makes it possible to obtain in the expanded resin-made easily _s closed cells. Obviously, the resole also contains an acidic hardener (catalyst), which ensures the polycondensation reaction of the resole to the easily made resin.

The lightened resin fills all of the voids between the foam particles.

Preferably, in the product according to the invention, the foam particles are in contact or close together. In practice, the volume of the final material is 5 to 25 % more than the volume apparent foisonne * of the foam particles.

For example, if the finished molding is to have a volume of 1 liter, one uses essentially 1 liter (compacted debris volume) of foamed polystyrene spheres with an average diameter of 6 mm and O ₅ 2 to 0.4 to fill the voids between these spheres mm liter balls of expanded polystyrene having an average diameter of 0.8 and a sufficient amount formo-phenolic resin foams of this resin by _$ thus the entire remaining between the balls of polystyrene cavities using a slightly resin made a density between 50 and 500 g / l to be filled.

It is possible for products to be foiled within certain limits Obtain bulk density by:

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- either the density of the easily made resin varies without changing the amount and granulometry of the spheres

- Or keeps the density of the modified resin constant, and the granulometry of the spheres and the amount of balls used (by modifying the amount of small balls in relation to the large ones).

The products according to the invention have remarkable properties, fire resistance, mechanical resistance with regard to their density and electrical insulation (this is often below 0.035 kcal / m / h ° C). They are in the form of blocks in which there are no interconnected cavities, thus avoiding any water absorption by these products and molding resins, filled or does not allow penetration of these resins into the interior of the product on all surfaces of the product.

The invention also relates to a method for producing the new products described above. This procedure is characterized in that a given amount of emulsified resol containing the necessary ingredients (Hardener, pore-forming agent, surface-active agent) contains, in a bed of foam particles, which one previously in a mold brought, injected, then increased the temperature of the mold, so that the foaming and the polycondensation of the Formo-phenolic resole is made until the mold is filled without reaching a temperature that a possible one Softening of the foam particles.

It is noted that the balls of foam particles are never subjected to pressure during manufacture of the product except possibly during the introduction of the particles

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into the mold, this pressure (low) then being used to loosen up the particles (dl £ Oisonner) _{or the like}

Although one non-enveloped foam member away can use ₀ is the preferred method of the invention is to bring about ₀ © di Vorumhüllung of the particles by means of a resin emulsion and introduce the vorumhüllten particles into the mold to cause foaming of the resin ,,

The heating of the formo-phenolic resin to carry out the foaming and crosslinking of the formo-phenolic resin can be effected by any known means. However, it is noted that due to the _s ι fact that initially the foam beads (coated or not), the entire mold fill out "possible and even very advantageous to carry out this Eritfärmen by means of a high-frequency current =.

You could find _s that the products obtained _s had _s even more remarkable thickness a very great homogeneity in carrying out the invention "is understood as ,, that the foam particles are not only fully and regularly distributed throughout the mold volume _a but also that the cells of the easy-made formo-phenolic haraes are completely regular ο This last phenomenon is probably based on the fact _B that the made easy © resin is never in a remarkable thickness <>

Obviously, the invention allows the creation of molded parts of very different shapes, which consist of products according to the invention "If you have in particular mats or fabrics made of glass in the interior or on the surface of the mold " impregnates the formo = phenolic Resin (then used in slightly larger quantities than previously described) the mats or fabric and you get a composite material with interesting properties »

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It is also possible to manufacture parts that contain reinforcing elements or inserts of different nature are arranged inside or preferably in the surface of the parts in products according to the invention. Man can also provide decorative elements on the surface of the products according to the invention.

It has also and very advantageously been possible to produce easily made parts by working inside the parts according to the invention has provided porous fillings, rigid or flexible, which themselves are made with the aid of foam particles (For example, fillings made from expanded polystyrene by agglomeration of beads) was. If a slight excess of formo-phenolic resin is used, the latter will penetrate its expansion into the cavities of the porous fillings by forming a complex material, that has very interesting properties.

The following non-limiting examples illustrate the invention in more detail.

example 1

A mold with an internal volume of 1000 liters (dimensions 2m50 χ 4m χ 0.10m) is filled with a mixture of 1000 liter spheres of foamed polystyrene (density 12 kg in m ') with an average diameter of 6 mm and 400 liter balls made of foamed polystyrene (density 20 kg in m ^) with an average diameter of 0.6 mm. About 40 kg of emulsified formo-phenolic resin, formed from 30 kg of resole, 3 kg of hardener (acidic), 7 kg of pore-forming agent (Freon) and 30 g of surfactant, are injected. The whole is heated to 45 ° C. for about 1 hour. The sheet obtained from the mold is hardened in a drying oven at 70 ^° C. for about 2 hours.

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Example 2 to 6

The technique used in these examples is the Vorumhüllung said _s which in a preliminary operation for covering the balls of expanded polystyrene (density 12 kg / m ^) is made with a certain amount formo-phenolic resin which is in the form of an emulsion and a propellant (for example 20 to 30 wt% _s calculated on the resin) ", a surface-active agent (for example used in a ratio of 1 to 3 wt% _s calculated on the resin) and an acidic catalyst (for example 2 to 10 wt% _s calculated on the resin) contains _s then in a second step these pre-coated balls are placed in a mold _s closes the mold and heats the material in the mold by means of high frequency (27 kHz sent through the panels) «The duration of the heating is considerably shorter than with the classical technique, since this duration is of the order of one minute.

By varying the amount of the spheres and the resin _s has been obtained sheets with the following properties;

ystyrene balls formo-
phenolic
resin Compression
resistance
(kg / cm2) Isolation
coefficient
(kcal / m / m2 / h / oc m3 of 6 mm in diameter
m3 from 0.8 to 2 mm in diameter 20 kg 1.66 O ₉ O296 m3 of 6 mm in diameter
m3 from 0.8 to 2 mm in diameter 30 kg 2 _s 4l O _s O292 m3 of 6 mm in diameter
m3 from 0.8 to 2 mm in diameter 80 kg 2 _s 6l O _s O32 m3 of 6 mm in diameter 40 kg 2.49 0.0282 m3 from 0.8 to 2 mm in diameter 40 kg 3 _a 7O O _s O36O

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Example 7

A composite panel has been made with a glass mat on both surfaces and in the middle contains a material according to the invention. One lays completely

ρ first a first glass mat (mat of 300 g / m and a Thickness of about 0.7 mm) on the bottom of the mold, then the normal amount is placed on this mat according to the invention Polystyrene balls made with the help of an emulsion of formophenolic Resin (as described in Example 2) are pre-wrapped and another amount is added Emulsion of formo-phenolic resin added about the same 1.2 kg of resin per square meter of the panel to be produced, a second glass mat, identical to the first, is placed on the upper surface of the spheres, and the mat is closed Form and one subjects the whole to a heating (for example up to 40-5O ° C) to the formo-phenolisehe To foam and crosslink resin.

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Claims (8)

OUR ACTS: 2279 / IO SOCIETE INDUSTRIELLE ET COMMERCIALE DES CHARBONNAGES - SICCA 6 rue de Tehran, F-75OO8 Paris (France) New composite product based on foam and formo-phenolic resin and process for its manufacture, claims: 1. New composite product, characterized in that it consists of foam particles _s whose volume is 75 to 95 % of the bulk volume of the particles and between these particles has an easily made formo-phenolic resin with a density between 50 and 500 g / l. 2. Product according to claim I _9, characterized in that the show particles are spheres made of foamed polystyrene. 3. Product according to claim 1 or 2, characterized in that spheres with at least two different granulometries used · " 809838 / 090B 4. New product with at least one layer of one Product according to claim 1, characterized in that it also contains reinforcing elements or inserts or lightweight elements which is bound to the product of claim 1 by the easily made formo-phenolic resin are. 5. A process for the manufacture of a composite product consisting of foam particles, the volume of which is 75 to 95% of the various volumes of the particles and between the particles an easily made formophenolic resin having a density between 50 and 500 g / l is provided, characterized in that, that a mold is filled with the particles and an appropriate amount of the resin containing a foaming agent and an acidic catalyst, and that the whole is heated to a temperature sufficient to cause foaming and crosslinking of the resin but below the softening temperature the particle lies. 6. The method according to claim 5, characterized in that the formo-phenolic resin contains an emulsifier and in Form of an emulsion is used. 7. The method according to claim 6, characterized in that the particles and the resin in the form of with a resin emulsion coated particles are brought into the mold. 8. The method according to any one of claims 5 and 7, characterized in that the heating of the material in the mold caused by high frequency. 809838/0909