DE1217601B - Process for the production of a sound and heat insulating material mixture from particles of a granular material of an organic nature and a foamed binding agent - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

B 29 h

German class: 39 a6- 7/20

Number: 1217 601

File number: D 21523 X / 39 a6

Filing date: October 19, 1955

Opening day: May 26, 1966

The invention relates to a method of manufacture a sound and heat insulating mixture of particles of a granular substance of organic nature and a foamed binder, the granular material of which is preferably made from rubber crumbs, cork or sawdust with a particle size of 0.1 to 3 mm in a ratio of 2 to 14 parts by volume to 1 part by volume Total content of natural rubber or resin in the binder.

One known method is waste sponge rubber used, which is brought into a foamed latex mixture in crushed form, wherein molding the mixture while it is still in its foamed state and then froze. Practice has shown that the product obtained in this way has relatively small pores contains, which are essentially completely enveloped by the walls of the binder foam. This results in a relatively large amount of material and at the same time only in proportion poor insulation against sound and heat.

It is also known to spread a foamed mixture on a substrate before the heat treatment and to carry out the heat treatment in a humid atmosphere.

The invention is based on the object of directing the method described above so that a large number of interconnected cavities are created, which are generally exposed to the outside air are open and in some cases have significantly larger dimensions than the particles of the granular substance, in order to achieve particularly good sound and heat insulating properties with little material expenditure.

In order to solve the aforementioned problem, the method is characterized according to the invention: that particles of the granular substance mixed into the liquid binder, then the mixture foamed and then the foamed mixture is subjected to a heat treatment in which the Gas bubble enclosing envelopes of the binder foam are destroyed before the parts of the granular Start to excrete.

By destroying the envelopes of the binder foam enclosing the gas bubbles, before the When granules begin to separate out, there is a very specific structure in which the particles become granular Materials are locally connected to one another in the form of straight and branched chains and a large one Form a number of communicating cavities which are generally open to the outside air and sometimes have significantly larger dimensions than the particles of the granular material. The through

Process for the production of a sound and
heat-insulating mixture of particles
of a granular substance of an organic nature and
a foamed binder

'Applicant:

Durie & Miller Limited,

Haslingden, Rossendale, Lancashire

(Great Britain)

Representative:

Dr.-Ing. H. Scheller, patent attorney,

Aachen, Zollernstr. 1

Named as inventor:

Frank Somerville Roberts,

Great Meadows, Prestbury, Cheshire

(Great Britain)

The diameter of these cavities can be from a fraction of a millimeter to 3 or even 4 mm.

This special structure gives the product excellent sound and noise compared to the previously known product heat-insulating properties and one when walking (e.g. on the laid carpet) as pleasant perceived softness. The method also has the advantage that with it the generation of the mentioned large cavities is possible in a particularly simple way.

In the process, contrary to all expectations, it has been shown that the fine-grained substance by no means agglomerates and sinks during the destruction of the foaming state. Rather, the above-mentioned cavities remain after drying.
The mixture of substances produced by the process can be used for numerous purposes in industry and household and is particularly suitable as a base for carpets and other floor coverings and can even be attached or attached to the underside of the carpet material in such a way that the carpet material is cut to any shape can be without the edges having to be framed afterwards.

The foamed mixture is expediently placed on a support before the heat treatment spread out.

It is also advantageous that the heat treatment to prevent skin formation on the surface

609 570/232

of the mixture is done slowly in a humid atmosphere.

An exemplary embodiment of the method is explained with reference to the drawing. It shows

F i g. 1 a section through the mixture of substances produced by the method,

F i g. FIG. 2 is a highly enlarged schematic representation of part of the FIG. 1 shown Mixture of substances and the way in which the particles of granular substance form straighter or branched chains are locally connected to one another, and

F i g. 3 schematically shows an embodiment of a device for carrying out the method.

F i g. 2 shows a base α made of burlap to which a layer of the finished material mixture has been applied; the layer is formed from particles b of irregular shape and size of rubber crumbs, which are locally connected to one another by a binder c indicated by the thick lines in the form of straight or branched chains. As can be seen, there are air spaces d between the particles b which extend through the entire depth of the finished substance mixture, with particles b _lt b ₂ , b ₃ forming bridges between the chains.

The structure of this mixture of substances is completely different from that of foam rubber.

In the case of the in FIG. The device shown in FIG. 3, 1 denotes a mixer in which a binding agent is produced with stirring by means of a stirrer 2. From the mixer 1, the binder passes through a valve-controlled line 3 into a foaming device 4. Granular particles b of rubber crumbs are introduced into the device 4 at 5 and the mixture is foamed by means of a stirrer 6.

After the foam has formed, the stirrer 6 is pulled out and the device 4 is tilted about a pivot point 7 in order to empty the foamed mixture at 9 onto a tissue support 8 that is passed by. The foamed mixture then moves under a trowel 10, whereby the application of a layer of uniform thickness to the base 8 is ensured.

In practice, the thickness of the layer can vary between 1 and about 120 mm.

The coated substrate moves through a drying chamber 11, where it is ^{dried at a temperature of, for example, 95 to 105 °} C. to prevent skin formation on the surface of the mixture.

The dry, coated substrate emerges at 12 from the drying chamber 11 and runs between two cutting knives 13 (only one of which is shown) cutting its edges, whereupon the coated substrate is passed over rollers 14 and wound up at 15.

The binder can be a plastic aqueous solution or suspension of an adhesive made of natural or Be synthetic resin. A binder that is preferably used consists of a rubber-latex mixture with the usual additives such as stabilizers, vulcanizing agents and the like Synthetic rubber latexes, copolymers of butadiene and styrene or artificial ones Natural, synthetic or regenerated rubber latexes can be used. Also is it is possible to use aqueous suspensions of synthetic resins such as polyvinyl chloride or polyvinyl acetate.

As particles of the granular material of an organic nature, crumbly rubber waste is preferred, how he z. B. when grinding the rubber of used car tires is obtained, which is usually for the production of rubber soles and heels is used. But it can also be cork or Sawdust can be taken.

The binder, a rubber-latex mixture, can consist of the following components (in parts by weight) :

130 parts of rubber latex concentrate in paste form of thickened latex with 60 to 70% rubber, about 10 ° / ₀ non-rubber components, balance water,
Regenerated dispersion,
Sulfur,

50 parts
2.5 parts
0.75 parts
5 parts
100 parts

Zinc diethyl dithiocarbamate,
Zinc oxide,

a 5% aqueous sodium alginate solution,

, Is required for the desired viscosity, 25 parts of a 10 ° / ₀ aqueous solution of casein and as much water as is.

200 parts by weight of red rubber crumbs corresponding to 2.4 parts by volume of the volume of the rubber in the latex mixture are introduced into this binder produced in the mixer 1 and introduced into the device 4 with vigorous stirring to generate air bubbles in the mixture. After the end of the mixing and foaming process, the device 4 is tilted to place the foamed mixture at 9 on the base 8, e.g. B. made of jute fabric to empty. The foamed mixture is then spread evenly on the base 8 by means of the tartboard 10 and then the coated base is moved into the heated drying chamber 11, where it is slowly heated at a temperature of, for example, 95 to 105 ^° C. in a humid atmosphere to prevent skin formation on the Surface of the mixture is dried.

The binder can also consist of a rubber-latex mixture with the following components:

58.9 kg rubber latex concentrate in paste form made from thickened latex with 60 to 70% rubber, about 10% non-rubber components, the remainder water,

24.95 kg black regenerated dispersion,
10.42 kg of a stabilizer,

73.4 ecm of a 10% solution of a sulfonated

Fatty alcohol,

208.9 g of a sodium salt of a polymeric alkylarylsulfonic acid,

998 g sulfur,

998 g zinc diethyl dithiocarbamate,

998 g mercaptobenzothiozole,

1995 g zinc oxide,

99 g bentonite,

293 g of an antioxidant,

41.8 kg of a 5% aqueous sodium alginate

solution,

41.8 kg of a 10% if aqueous casein solution and as much water as is necessary to achieve the desired viscosity.

This binder is 60.6 kg of granular cork, which is about 5 parts by volume of the rubber in the latex mixture is added at 5 with vigorous stirring to form air bubbles in the mixture. Then the foamed mixture is spread on a base and the coated base in dried in the manner described above.

As a base for the mixture of substances, for example, bases made of loose jute fabric are suitable Cotton fabric, paper or polyamides. However, it is possible as a material for the base Synthetic resin, leather and other, relatively gas-impermeable materials to be used, depending on the Purpose for which the end product is intended.

It is also possible to distribute the mixture of substances on a wire mesh, from which it is after Drying can be stripped.

Claims (3)

Patent claims: 1. Process for the production of a sound and heat insulating mixture of particles a granular substance of organic nature and a foamed binder, its granular Fabric preferably made of crumbs of rubber, cork or sawdust with a particle size of 0.1 to 3 mm in a ratio of 2 to 14 parts by volume to 1 part by volume total content of natural rubber or Resin stands in the binder, thereby characterized in that the particles of the granular substance are mixed into the liquid binder, thereafter the mixture is foamed and then the foamed mixture is subjected to a heat treatment is subjected, in which the gas bubbles enclosing envelopes of the binder foam be destroyed before the particles of the granular matter begin to separate out. 2. The method according to claim 1, characterized in that the foamed mixture before Heat treatment is spread on a pad. 3. The method according to claim 1 or 2, characterized in that the heat treatment for Preventing skin formation on the surface of the mixture slowly in a humid atmosphere he follows. Considered publications:
German Patent Nos. 531989, 914 318, 053; Austrian Patent No. 132,406;
Swiss Patent No. 164135;
French Patent Nos. 866 749, 1 006 149; U.S. Patent No. 2,147,362. 1 sheet of drawings 609 570/232 5.66 © Bundesdruckerei Berlin