DK157116B - Moulded cushion or upholstering material based on foam rubber or polyurethane foam with improved fire resistance, method for production of this material, and application of the material in manufacture of furniture - Google Patents

Description

DK 157116 B

The invention relates to a shaped foam or padding material based on foam rubber or polyurethane foam. The invention further relates to a method of making such material and to the use of the material in the manufacture of furniture. The term "cushion or cushioning material" is here to be taken as broadly understood as encompassing not only material for pillows, such as sleeping pads, and mobile upholstery, but for all forms of blood, elastic or shock absorbing properties desired by eg. for cushions, mats, mattresses, substrates, intermediate layers, etc. The characteristic properties of such pillow or upholstery material are generally bloodiness and elasticity. It is believed that the material according to the invention will be mainly on the basis of molded polyurethane foam, given that such foam predominates in the cushioning and upholstery materials used.

A lot of work has been done on the problem of reducing the risk of fire and the dangers that arise, 20 when a fire occurs. This is of particular interest in mobile companies, as fires can often be traced back to ignition of pillow or upholstery material, e.g. chair cushions or pillows and mattresses. In such cases, deaths may occur due to the inhalation of 25 toxic rye and gases emitted during combustion.

More recent legislation has been introduced or proposed in the United Kingdom and elsewhere to reduce the risk of ignition and spread of fire in padded mobiles and other padded 30 home furnishings. In British Standard no. 5852, there is disclosed a test method, usually referred to as "the smoldering cigarette test". It is important that padded mobiles and other padded home furnishings pass this test to be acceptable to wholesalers and 35 customers. Another test method is set out in British Standard No. DD58: 1978 and is usually referred to as 2

DK 157116 B

"Butane flammeproven".

More recently, methods have been studied to increase the resistance of carbon to char. In some methods, the final foam is dipped in a chemical. In other methods, an additive is incorporated into the latex foam mixture during the foam preparation step. However, none of these methods presently provides the ideal solution to the problem, as, for example, 10 unacceptable deterioration in the properties of the foam rubber may occur. In another attempt to solve the problem, a cellular polychloroprene product in plate form has been used to enclose the upholstery material in chair upholstery, but this is very costly and, in addition, toxic gases (HCl etc) can be formed / if the material becomes attacked by fire.

It has now surprisingly been found that a thin layer of a filler-containing non-gel rubber latex foam based on a hydrocarbon rubber possesses considerable resistance to ignition and flame propagation. In the case of combustion, less toxic materials are developed, as halogen-containing components are not used. It is particularly surprising that a foam made from a hydrocarbon rubber latex, such as styrene-butadiene rubber, is effective in increasing the fire resistance, since such gums were expected to be more, not less flammable.

The material according to the invention is characterized in that it consists of a foam or polyurethane foam shaped or cushioning material which is encased in a thin layer of a filler-containing non-gel latex foam made of a latex containing a styrene-butadiene rubber latex or polybutadiene latex or a mixture thereof and 200-350 parts by weight (per 100 parts by weight of dry rubber) of a fire-retardant filler. As to the peculiarities of the method and application

DK 157116B

3 according to the invention, reference is made to the characterizing part of claim 3 and to claim 5.

Non-gel guiranilatex foams have been known for many years, see, for example, Untiedt, U.S. Patent Nos. 1,777,945 and 1,845,688, and English Patent No. 332,526 (Dunlop).

See also "Textile Month" July 1969, 50-52 and Modem Car-pet back-finishing "R. Pollock, Textile Institute and Industry, January 1979. One of the benefits of such foams is that they can be prepared from blends containing- 10 a large amount of filler, for example 200 to 350 vhg (parts by weight per 100 parts of rubber). For example, as a filler for use as a carpet backing, mention may be made of 1 or calcium carbonate, which is used in the process according to the invention. -gel rubber latex foam is prepared from styrene-butadiene rubber latex or polybutadiene rubber milatex.

For the material of the present invention, a fire retardant filler is used in the non-gel latex foam and as such filler, 20 aluminum trihydrate is preferred. Non-gel foams mixed with 200 to 350 wg of such a filler can be foamed, dispersed and tarred just as in the manufacture of conventional carpet backing or carpet backing. Preferably, the foam is made without stitching material, that is, without hessian or other material as integral backing, using, for example, the "Monocel" technique ("Monocel" is a trademark). The foam then becomes a thickness of e.g. 7 mm on the cushion or cushioning material foam by molding to the inner mold and then laminating by adhesive to form a foam block encased with a thin layer of fire-resistant, non-gel rubber latex foam. This thin layer protects the foam block from ignition caused by an external heat source.

Using a non-gel rubber latex foam layer provides a relatively inexpensive, yet effective

DK 157116 B

effective method for increasing the fire resistance of blunt, foamy pillow or upholstery material. Furthermore, the soft and comfortable feel of the pillow or upholstery material is noticeably enhanced.

Below is a typical mixing formulation for a non-gel foam which is suitable for wrapping a molded foam or polyurethane foam-based cushion or cushioning material to obtain a cushioning or cushioning material. according to the invention, which can pass the smoldering cigarette sample.

By weight Wet weight "INTEX® 100" 1) 100.0 153.8 15 Sodium lauryl sulfate 0.75 2.5

Sodium hexamethapiophate 0.5 5.0

Sulfur 2.5 5.0

Zinc mercaptobenzthiazole 0.5 1.0

Zinc diethyl dithiocarbamate 1.5 3.0 Zinc oxide 3.0 6.0

Antioxidant 1.0 3.0

Emulsifier - long chain sulfosuccinamate ("ALCOPOL FA") 2 ^ 5.0 15.0 25 Aluminum trihydrate 225.0 225.0 1) "INTEJ" is a 65% by weight styrene-butadiene latex containing a bound styrene content of about . 23% and it is sold by EniChem Elastomers, Ltd.

30 2) "ALCOPOL FA" is sold by Allied Colloids Limited.

EXAMPLE

In the process of the invention, a shaped polyurethane foam ("Dunlopillo® grade D7") cushion or cushion material was coated with a 1 cm thick layer of filler-containing non-gel rubber latex foam formula

DK 157116 B

as stated above, using a adhesive by known mobile fabrication technique, a lamination was performed. The material made according to the invention in the form of rectangular blocks was tested by the The Furniture Industries Reseach Association, Stevenage, Hertfordshire, England, together with non-foam layer control samples, in flammability tests in accordance with Bristish Standard Specification 5852 Part 1, 1979, and British Standard Specification DD58: 1978 using various textile fabric cover materials. In the BS 5852 samples, the material passed the sample each time, the foam layer being only superficially damaged. by the more stringent test (BS DD58: 1978), the resistance to ignition was increased, so that the material passed the tests using the sources of ignition 4 and 5, while the result obtained without the foam layer failed.

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Claims (5)

1. Foam or cushion-shaped cushion or cushioning material having improved fire resistance, characterized in that it consists of a cushioned foam or cushioning material made of foam rubber 5 or polyurethane foam, which is covered by a thin layer of a filler-containing non-foaming material. gel latex foam, made from a latex containing a styrene-butadiene rubber latex or polybutadiene latex or a mixture thereof, and 200-350 parts by weight (per 100 parts by weight of rubber) of a fire-retardant filler. Pillow or upholstery material according to claim 1, characterized in that the fire retardant filler is aluminum trihydrate. A method of making a molded pillow or cushioning material according to claim 1 or 2, characterized in that a molded cushioning or cushioning material is made of foam rubber or polyurethane foam with a thin layer of a filler-containing rubber latex foam made of a latex mixture which contains a styrene-butadiene rubber latex or a polybutadiene latex or a mixture thereof and 200-350 parts by weight (per 100 parts by weight of rubber) of a fire retardant filler. 4. A process according to claim 4, characterized in that the flame retardant filler is aluminum trihydrate. Use of the shaped pillow or upholstery material according to claim 1 or 2 in the manufacture of mpbles.