DE2547860A1 - FOAM LATEX MATERIAL AND METHOD FOR MANUFACTURING IT - Google Patents

Description

Foam latex material and process for its manufacture

The invention relates to a foam latex material, which by pressing can be provided with a profile, as well as a method for its manufacture.

Such foam latex materials are used, for example, for coating the Back of floor carpets, used as a carpet underlay and the like. They are present in a two-dimensional distribution.

It has traditionally been difficult to produce cellular or foamed polymeric material, and particularly elastomeric foamed material

to provide a structure or indentations. One of the attempts known to the person skilled in the art is the processing of the foamed Plate material with indentations producing form rollers at special temperature conditions, the foam in predetermined Areas collapses and thereby the desired

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Pattern is obtained. Chemical processes are also known, beil which the foaming agent or reactants with the material j agent on specified areas of the surface of the polymer mat ^ - riales must be applied before the material is foamed. Either only the areas that will later be raised are foamed should, or instead the areas that should be deepened afterwards are networked so that they do not ger after foaming form foamed areas. j

In the process in which the foam material is compressed using indentation forming rollers, the temperature and pressure must be adjusted very carefully in order to prevent a general collapse of the foamed material. The use of chemical processes presents difficulties because additional work equipment is often required which will place the chemical reagents in precisely the desired areas and because further processing steps are required to ensure that the foam material is fully foamed. ■ and maintains a stable structure. These proceedings have got over it! also proven to be very ineffective when they are to be used with elastomeric foam materials and especially with latex materials that do not belong to the gel type. Such materials: are however commonly used as backing for textile structures and for the production of foam rubber pads. j

There is therefore a need for a method by which foaming

indentations can be made quickly on the sheet material, \

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ORIGINAL IN

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[with which stable indentation patterns can be obtained and which easy in the manufacture of elastomeric foam backed textiles, carpets and the manufacture of elastomeric foam sheets for underlay purposes and the like. Can be used.

The essential features of the invention are set out below, j

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Are moderate amounts of other materials such as I. PVC plastics, polyolefins, waxes and the like in powder form disper-j yaws, the material can simply be provided with indentations after foaming, that the foamed sheet or Web material is passed through cooled, indentation forming rollers. More precisely, foamed latex materials, in which particles with a melting point at or in the Nä-j

are dispersed at the temperature used for foaming, leicljit are thereby provided with indentations that the temperature of the foam material to the melting temperature of the mixed, solid j Particles having material is raised, that then the foamed material under an impression-producing forming roller

that is passed, and that then the material is cooled and / mixed with material "hardened ¹¹ , whereby the foam remains held down in the areas depressed by the forming roller.

The present invention can be used with particular advantage, on the underside of a rear with resilient latex foam provided carpet to generate impression patterns. Which he-

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Finding can also be used to create impressions on one or both of the surfaces of a resilient, foamed Use elastomer underlay material in sheet or sheet form. The impression patterns can easily be of the tendency to occur during use Withstand compression deformation and lose yourself at The ambient temperatures and conditions normally encountered do not result from the foam structure, not even when the material is cleaned, used or stored.

The present invention will now be described in detail.

As a floor covering and the like. Carpet and textile materials used are on the underside with a foamed, resilient elastomer Coated material. This coating or reinforcement is usually carried out in such a way that a rubber-latex foam mass is on the underside Is distributed, in the suitable stabilizing substances, fillers, gel stabilizers, thick matter and the like. Contain are. The further treatment of the coated fabric takes place in such a way that it removes the volatile constituents and in particular is dried to remove water, and then heated to cure the elastomeric foam. If more suitable Composition of the elastomeric foam mass also takes place crosslinking, so that the material is a gelled foamed Structure. However, non-gelled foam materials are also used for the stated purpose. For the stated purpose Common elastomeric materials used include elastomeric styrene butadiene materials mixtures of styrene butadiene

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Materials, and mixtures of styrene-butadiene elastomers with \ natural rubber or polyisoprene. The styrene butadiene rubber can also be a carboxylated rubber of this type. the smaller amounts of a carboxylated monomer such as itaconic acid, citraconic acid, acrylic acid or the like are contained in the elastomeric monomer composition. Such latex elastomeric materials are widely used and sold for these applications; they are commonly called foamable SBR latex materials. i

The solid particulate material which is dispersed in the latex to render the foam compressible is used in the form of a finely divided powder. Among the materials that can be used for the purposes of the invention are polymers and wax-like! Materials that melt or soften in the range of 90 to 200 degrees Celsius; these include polymers present in powder form, such as poly-1 vinyl chloride, polyethylene, polypropylene, polyamides and waxes that melt at high temperatures. The melting or softening point must be in a range in which the foam is to be processed, and it must lie above the highest use temperature; genes that may occur in the envisaged use of the show product. Materials which melt at too low temperatures will with great probability be exposed to temperatures at which the material can be softened and the indentation pattern is destroyed. Materials substantially have a melting point lying above the preferred temperature range, can in practice not ver-i apply, since the foam of a processing that at the Schmel-j

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zen of the material containing particles at a sufficiently high temperature occurs, cannot withstand. In this context, the melting temperature is understood to mean the temperature at which the material in the form of particles has melted or softened to such an extent that it becomes plastic. With pure substances it is a real melting, while at

how
polymeric materials / PVC the change of state is a softening to a semi-molten plastic state. Although this temperature is often referred to as the melting temperature, it should more precisely be referred to as the softening temperature. The materials most suitable for practical use soften or melt in the vicinity of 150 ° C; a typical such material is PVC in powder form.

The incorporation of the particles takes place in that the powder thoroughly; is dispersed in a foamable latex material before it is; is poured or the fabric structure is coated. The dispersing the powder is usually done by simply mixing; uniform dispersion in the latex material is desirable. | The amount of powdered material to be used can be varied over a wide range. Quantities from 2o to 15o:

% By weight of the solid latex components can be aimed at Use for purposes with satisfactory results. The latex mass is then foamed in mixing devices which i Process batches or work continuously, with air or an inert gas being built into the j latex mass, so that a! thick foam-like foam is generated. ;

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The application of the foamed latex mass to the carpet can be based on _; many ways take place, such as by rolling, spraying, supply \ share with a knife or by applying the Latexschauraes i on the surface with a doctor blade. The coated arrangement
is then heated to dry and cure the foam. The j foam is then further heated to the melting temperature of the 'form in the present particulate material, whereby it is softened or melted j; then the foam is processed with a cold, indentation-producing roller, whereby the foam mass | is cooled and solidifies with the indented pattern. j

The present invention is applicable to a wide variety of foamable gel-type and non-gel-type latex compositions;

use. The greatest benefit is when using them together!

achieved with non-gel foam masses, as this was previously more difficult i could be satisfactorily provided with impressions; but also i the application on gel foam masses is within the scope of the!

lying invention. :

ί For a better understanding of the invention, j

! further elucidating some specific embodiments of the

Invention described by way of example. j

The following examples are foam materials, those using a foamable, non-carboxylatedί

Styrene-butadiene latex material. The latex mate- j

rial was mixed in batches in such a way that a foam of medium ι

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[Density was obtained. The foam was then applied to the back [of a 4 mm thick plucked carpet weighing 210 g / m 2 (7 oz / sq) distributed. The coated squares were left to dry and curing the foam in an oven at 140 ° C for 15 minutes. Then they were placed in an oven for 5 minutes. These heated samples were then removed from the oven and passed under a cold indentation forming roller to print the pattern. A typical waffle pattern was used for these experiments; in the case of the pressable one according to the invention However, a variety of patterned forming rolls can be used, including dimpled, corrugated, and foam rolls similar to those widely used in industry.

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ORIGINAL INSPECTED

Table 1

Foam material composition (parts by weight in dry matter)

Sample No.

component

cn ο CD OO to KJ

O KT)

SBR latex (1) loo loo loo loo loo loo κ:
LJ " I. Sulfosuccinamate
(for support
foaming) 3 3 3 3 3 3 -C- VO
1 Amine oxide
(for stabilization
of the foam) o, 5 o, 5 o, 5 o, 5 o, 5 o, 5 Sodium lauryl sulfate 2 2 2 2 2 2 sulfur 2.5 2.5 2.5 2.5 2.5 2.5 zinc oxide 3, ο 3, ο 3, ο 3, ο 3, ο 3, ο Zinc dithiocarbamate 1.5 1.5 1.5 1.5 1.5 1.5 Zinc mercaptobenothiazole l, o l, o l, o l, o l, o l, o Calcium carbonate 15o 15o loo 15o loo - PVC in powder form (2) O 25th 5o 5o loo

Aluminum hydrate

Polyacrylate (for thickening) (3)

Water (4) 6.95

up to the required viscosity
15.95 6.95 21.95

21.95

15o

6.95

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.Remarks:

:1. SBR latex: non-carboxylated styrene butadiene latex with 28% bound styrene. Solids content 61%.

2. Powder PVC: crushed polyvinyl chloride resin. BP Chemicals Ltd. Breon P 13o / l powder, fineness 300 mesh (maximum), sp / c = O _r 6 3 -o, 69, o, 5% in cyclohexanone.

3. Thickener: So much is added that in the finished mixture a Brookfield viscosity of 35oo cps is obtained, RVT # 4 spindle and 50 rpm.

4. Water: So much is added that the solids content of the finished mixture is 77% by weight.

Sample No. 1 is a comparative sample obtained without adding; PVC was made in powder form. This latex material did not leave any indentation patterns produced by the forming roller when it was applied to plucked carpets in the manner described above and provided with indentations. The different amounts PVC powder containing samples no. 2 through 5 retained the indentation pattern when they ran out of the indentation forming roller. This can be explained by the fact that the dispersed, Particle-containing PVC material at the high temperature (150 ° C.) shortly before entering into which the depressions are i

I forming roll has reached a semi-molten state.

The cold forming roller is used to create the foam in the desired shape

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to depress ster and thereby fix the indented pattern, that the material present in particulate form is cooled and converted into the solid state, in particular in the depressed areas. As a result, the depressed sections of the foam material are fixed in their position. It will be understood that an essential condition is that the particulate material used melt or softens and then rapidly solidifies as it cools down. The particulate material does not have to be PVC, other polymers Powdered materials can equally be used, e.g., high melting point wax materials. It is also pointed out that the process of making a foam! - mass with powder particles leads to a heterogeneous dispersion and not to a solution or mixture of the two polymer components.

By using PVC in the present invention obtain further advantageous properties of the finished foam material; this includes increased wear resistance, the adjustability of the generation of pits and the delay of inflammation.

The extent to which depressions remain depends partly on the used amount of dispersed powder particles. With the together When sample 2, which contains only 25 parts of PVC to 100 parts of latex, only slight depressions remain. Against it takes the extent to which pits remain with the amount of dispersed PVC particles up to sample No. 5, at the loo

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ORIGINAL INSPECTS)

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Parts of PVC to loo parts of latex are used.

j In addition, non-indented sheets of foam; i. I.

j material tested in a wear testing device (WIRA Dynamic _:

I j

! Load Tester). When examining a specimen on the · \ disks strikes and the thickness decrease is measured. As from the test results shown in ■ ■ Table 2 below ■

i can be seen, in the compositions of the foam material ¹

les of samples 2 to 5 a significantly improved wear resistance ; preserved. :

Table 2 Test results for the foam materials according to Tab.

Sample No.

Decrease in thickness (% )

for loo surcharges 5.9 3 3.2 2.9 2.7

with 500 serves 8 3.5 4.4 4.2 2.7

for looo surcharges 9 3.5 5 4.2 2.7

Flame tests were carried out with 25.5 cm large, on the back: Carpet pluck samples provided with foam material and prepared according to Samples 1, 3, 5 and 6 as indicated above

were, however, not provided with indentations. j

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j The flame test carried out is in the publication

7 2 / 7ooolo by the British Standards Institution and is usually called the "Hot Nut Test". In this test, a stainless steel hex nut is used with a distance between the flat side surfaces of 9.3 mm (15/16 inch) and with
a weight of 30.2 g heated to a temperature of 90 + 20 ° C; it is then placed on the surface of the foam material and the burn time and char radius are measured. A carpet made with a non-PVC foam material; had been coated according to sample 1, had to see after 18o. ! be erased, and the char radius reached the edges; of the carpet. Sample 3 came after 12o see. by itself to he-; erase with a charring radius of 35 mm. Sample 5:

came to 65 sea. to extinguish, with the charring radius 2o mm i

from I.

fraud. Thus it is seen that PVC powder as dispersive \ giertes material in particle form with a certain improvement when using /: get the opposite of ignition resistance
will.

It should be noted that the invention described above
consists in dispersing particles of a powder material in a latex foam, thereby forming the latex foam, as above
described, the property that he receives with impressions
can be provided. The foam latex composition obtained can be used for
Coating the back of carpets or for manufacturing
Foam material panels are used in particular for underlay purposes. The creation of the indentations can be used as part of the

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Manufacturing steps are carried out; the cured foam product however, it can also be stored initially and only later provided with indentations by bringing it to a temperature is heated sufficient to soften or melt the particulate j component, and in the material

then through a cold forming roller that creates the depressions ; works, whereby the material present in particulate form is rapidly cooled and converted into the solid state and

j thus the foam structure is fixed.

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Claims (5)

Claims 1. Foam latex material that is profiled by indentation can be, characterized in that it has an elastomeric latex matrix in which the particles of a crushed Solid in powder form with a softening temperature! are dispersed in the range of 9o - 2oo ° C, with its con! centration is 25 - loo parts of the latex components. 2. foam latex material according to claim 1, characterized in that | ß the crushed solid present in the form of particles is selected from the group consisting of polyvinyl chloride, polyethylene, Polypropylene and wax is formed. 3. foam latex material according to claim 1 or 2, characterized in that that the elastomeric material is a styrene-butadiene latex elastomeric material. - 16 - 609822/1 060 4. Foam material according to claim 1, characterized in that the elastomeric latex material is a styrene butadiene latex elastomer and the particulate solid is polyvinyl chloride. 5. A process for the production of a foam latex material provided with indentations in sheet or web form, characterized in that that a sheet or sheet of foam latex material according to one of claims 1 to 4 is produced, that the plate or web is heated to a temperature which is sufficient to soften the solid present in particulate form It is sufficient that the sheet or sheet of foam latex material is then provided with indentations in that it carried out by a cold forming roller that produces the indentations is, whereby the indented pattern is printed, and that the particulate solid on a is cooled below the softening point temperature in order to fix the foam material in the shape produced in this way. 609822/1060