DE2535180A1 - CUSHIONS, UPHOLSTERY AND MATTRESSES WITH ANTISTATIC PROPERTIES AND THE METHOD OF MANUFACTURING THEM - Google Patents

Description

PATENT LAWYERS

DR. WALTER KRAUS DIPLOMAL CHEMIST DR.-IN S. ANN EKÄTE WEISERT DIPL-ING. SPECIALIZATION CHEMISTRY D - 8 MUNICH 1Θ FLÜGGENSTRASSE 17 TELEPHONE 089/177061 TELEX O5-215145 ZEUS

TELEGRAM CRAUS PATENT

1143/4 - wt / li

G. D. SEARLE & CO. LIMITED, High Wycombe, Buckinghamshire,

Great Britain

Cushions, cushions and mattresses with antistatic properties and processes for their manufacture

The invention relates to the manufacture of pillows, cushions and mattresses and similar articles with antistatic Properties. When cushions, cushions and mattresses are mentioned in the present application, they should include all types of pillows and cushion materials, mattresses and mattress materials, upholstery and cushioning materials such as protective padding, padding materials, etc. are understood.

There are numerous cases in which it is essential or advantageous that cushioning materials such as mattresses or Cushions have antistatic properties, i.e. that they

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are made of materials that contain any static electricity that is formed on their surface, derive. For example, explosive mixtures can result in hospital operations in the operating room Oxygen and anesthetic gases accumulate and the pillows, for example on the operating table or The surgical chair used should be made of materials with antistatic properties be.

Usually such pillows and cushioning materials are used made of foam material that is independently covered with a sheet or sheeting of flexible material is covered with antistatic properties. For example, a piece of foam material can desired shape can be covered with a sheet of conductive rubber material, which is on the desired Cut and trimmed to size and shape. The manufacture or construction of such Pillows or mattresses is a process that requires specialist knowledge and is also a considerable amount of manual work necessary. These factors mean that the product is a little more expensive and that it is difficult to get one to produce a consistent standard product.

The present invention is therefore based on the object of a method for producing inexpensive antistatic To create pillows, cushions or mattresses of consistent quality.

The invention relates to a method for production of pillows, cushions and mattresses and similar objects with antistatic properties, in which a release agent or mold release agent on the mold surfaces is applied in a lockable form,

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a polyurethane transfer coating agent which Contains electrically conductive carbon black on the mold surfaces, which are coated with the mold release agent are, is applied, the transfer coating agent is allowed to dry and then inside the closed Form a plastic foam material. is initiated and then this foam material in Contact with the transfer material can expand, the foam material can set and then the The mold is opened and the molded body is removed therefrom.

The invention also relates to a pillow, a cushion or a cushioning material and mattresses or the like Articles made from foam plastic materials that have an integral surface skin that is formed during the deformation of the object and this skin is polyurethane and electrically conductive carbon black and has antistatic properties.

A particular advantage of the method according to the invention in the production of antistatic pillows, cushions or Mattresses (all of which are included in the term upholstery here) is the option of these upholstery with the required degree of strength, durability or stability. In particular enables the incorporation of conductive material into the polyurethane foam pad by selecting different ones Combinations and types of foam-producing materials to produce conductive foam with different degrees of strength, practically of almost rigid structures to extremely soft upholstery materials. It is therefore possible to consist of many rigid or semi-rigid structures to manufacture lightweight plastic material, whereby the structures have antistatic properties, as

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Alternative to making these structures from metals and metal-coated materials. Another advantage of the present invention is the ability to use upholstery to produce very different shapes and structures according to the special requirements of their use. For example, it is possible to manufacture cushions or cushions for surgical chairs that exactly fit the surface the well-known chairs fit, but are replaceable. Similarly, it is possible to use many upholstery materials with complicated ones Manufacture molds that are produced with the known method only at considerable costs can. Such cushioning materials are widely used to make medical equipment used in clinical operating theaters used to pad. These pads or pillows can also be used in all cases where sparks generated by static electricity present an explosion hazard, such as cushioning material in airplanes or in air traffic as a whole or as cushion and cushioning material in space capsules.

In the single figure of the accompanying drawing, part of a cushion is shown, which is produced according to the invention with the pillow still in the mold.

A mold release agent is first applied to the mold surfaces 1a of the mold 1 (for example, by Spray on) and a transfer coating is then applied to the mold release agent. The transfer coating 2 can be applied to the mold surfaces 1a of the mold by spraying, and it can be any common polyurethane transfer coating material contained in which finely divided soot has been incorporated. The transition coating contains at least 10 96% by weight

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electrically conductive carbon black and preferably 22 to 26%.

The transfer coating 2 is then allowed to dry on the mold surfaces 1a of the mold, although preferred is that only superficial drying occurs without strong crosslinking of the polyurethane material. Polyurethane foam materials are then injected into the mold and expanded to the inside of the Fill in the form.

These polyurethane foam materials can or can be non-conductive material, preferably at least Contains 3% by weight of carbon black. If they do not contain conductive material, then only the surface of the finished object .have antistatic properties and this is perfectly satisfactory. However, there will be the incorporation of conductive material in .the foam materials the conductivity properties of the finished item, and static electricity that is formed on the surface can, not only along the surface of the object, but also through its volume be derived. The cushioning materials thus contain a central foam body 3, which is either is conductive or non-conductive, together with an integrally formed skin 4 with conductive properties. Forming the foam body of the article in the presence of a transfer coating results the fusion of the two materials to form an integral object. This amalgamation is achieved by deforming the polyurethane foam as soon as possible after the transfer coating is created favored.

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The polyurethane foam material used for the body of the The article according to the invention is used should be of the type that has a skin on the surface of the This skin acts as a carrier for the transfer coating, which, while having the desired antistatic properties, has little durability against physical stresses such as tearing. The combination of a skin made of polyurethane foam with the pre-formed transfer coating provides a physically strong surface that the has desired and antistatic properties.

The pads according to the invention show the conductivity properties, that of the British Standards Institute in Specification No. BSS 2050 for Antistatic Articles used in hospital operating rooms. This standard of antistatic Properties is also for other applications of these cushions or upholstery as indicated above satisfactory. The following example explains the invention without restricting it.

example

A mattress according to the invention can be produced in an operating room cart or in the operating room table can be used. Such a mattress must have antistatic properties, to avoid ignition of potentially explosive gas mixtures in operating theaters.

A mattress is produced that has the following dimensions: 1.8 m by 55.8 cm by 2.54 cm thick (6 ft χ 22 ins χ 1 inch). A shape with these interior

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dimensions is made of epoxy resin as described above. The form is made with suitable injection and "Breathing" holes fitted so that the foam material be injected and the air can escape from the mold. The inside surface of the mold gets first sprayed with a common "mold release" agent and then sprayed with a transfer coating. This transfer coating is a varnish based linear polymeric polyurethanes in an organic solvent. It contains finely divided, electrical conductive carbon black (Cabat XC-72) in the proportions of 74 parts to 26 parts by weight. 0.5 Parts of polyoxyethylene, quaternary ammonium salt are also added to this mixture in order to reduce the antistatic properties Properties to improve. The transfer coating is allowed to dry for 1 minute and then the shape becomes locked. The components of the polyurethane foam are made and mixed as described below: 100 parts of a polyol (CARADOL 205/4 - "Shell Chemicals) are in the ball mill with 15 parts grind fine soot. In this mixture are 25 Parts of commercially available Freon (TCFM - Shell Chemicals) and 0.8 parts of accelerator (triethylenediamine) mixed in. The mixture is immediately before injection into the mold with 4,4'-diphenylmethane diisocyanate mixed in ethyl acetate in the ratio of 144 parts to 58 parts. Mixing takes place under Use of the usual mixing head of the injector.

Because of the length of the mattress, the foam materials are injected through an injection tube, which can be slowly withdrawn from the mold while the foam materials are being injected. With the injection is removed from the end of the mattress Injection hole started and the probe slows down

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drawn along the inside of the form, while the material is injected. The mold is therefore progressively filled with expanded foam. By using the skin-forming Foam it is possible to form a tear-resistant skin under the conductive transfer coating, and it is this skin that gives strength to the upholstery surface.

After the foam has set, the form is stripped off and the finished mattress is obtained. With this one Example one obtains a mattress which has a conductive surface, which consists of the transfer cover together with a semi-conductive and thus anti-static interior padding material was formed.

The mattress has a surface resistance of 18 to 25 x 10 and ⁶ ohms
static properties.

18 to 25 x 10 ohms and thus shows considerable anti-

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Claims (6)

Claims 1.j process for the production of pillows, cushions and Nw mattresses and similar items with antistatic Properties, characterized in that one is on the mold surfaces of a closable mold applies a mold release agent, a polyurethane transfer coating material, containing the electrically conductive carbon black, on the mold surfaces, which are covered with the mold release agent are coated, applies, allows the transfer coating material to dry, the interior the closed mold is charged with a plastic foam material and the foam material in contact with the The transfer material can expand, the foam material can set, the mold opens and the foam body takes from it. 2. The method according to claim 1, characterized in that g e k e η η ζ ei chnet that the transfer coating is a lacquer based on a linear polymeric polyurethane in an organic solvent and 22 to 26% by weight is 96 Contains soot. 3. The method according to any one of the preceding claims, characterized in that the plastic foam material is a polyurethane foam that contains electrically conductive carbon black. 4. Process for the production of pillows, cushions, mattresses and others as described in the example. 5. Cushions, cushions, mattresses and similar objects, produced by the method according to one of the claims 1 to 4. 6 0 9 8 0 8/0946 6. pillows, cushions, mattresses or similar items, Made from Schauni plastic material, with an integral Surface skin formed during the molding of the article, the skin being a polyurethane which contains electrically conductive carbon black and has antistatic properties. 60980 8/0946