Fire resistant material

Abstract

The present invention relates to inorganic-organic hybrids (IOHs), methods for their preparation and their use as fire resistant materials or components of fire resistant materials. More specifically, the invention relates to polyamide fire resistant formulations containing IOHs which have application in the production of fire resistant articles or parts thereof for use in the transportation, building, construction and electrical or optical industries.

Description

[0001] The present invention relates to inorganic-organic hybrids (IOHs), methods for their preparation and their use as fire resistant materials or components of fire resistant materials. More specifically, the invention relates to polyamide fire resistant formulations containing IOHs which have application in the production of fire resistant articles or parts thereof for use in the transportation, building, construction and electrical or optical industries. BACKGROUND OF THE INVENTION [0002] Materials based on organic polymeric systems (plastics) are widely used in the transportation, building and construction industries. A drawback of many types of organic polymers is flammability which limits their suitability in applications requiring flammability resistance and where regulatory authorities govern flammability standards. [0003] In commercially produced polymeric systems, flame-retarding species may be added during processing or forming of the materials to reduce the end product...

AI Technical Summary

Benefits of technology

[0067] It is known in the art that metal cations or anions associated with layered inorganic materials may be exchanged with organic ions through ion exchange processes. In a typical process, the layered inorganic material is first swollen or expanded in a suitable solvent(s) prior to ion exchange and then collected from the swelling solvent following agglomeration using methods such as filtration, centrifugation, evaporation or sublimation of the solvent. Ion exchange techniques with suitable molecules are known to be a useful method of increasing the compatibility between clay and organic polymeric binders, thus aiding dispersion of clay platelets into polymeric based matrices on a nanometer scale.

[0102] The present invention is useful for producing polyamide materials with favourable rheological properties for moulding including thin or intricate articles or parts thereof which maintain mechanical properties close to or exceeding that of the virgin polyamide matrix and which show improved fire performance in standard tests through resisting combustion by self-extinguishing when ignited, limiting flame propagation, and generating low smoke and toxic gas emissions. Such articles or parts thereof are useful for applications which require superior fire performance and in industries that are regulated for fire performance including transport, for example, air, automotive, aerospace and nautical; building and construction; and electrical or optical, for example, cables, wires and fibres.

Problems solved by technology

A drawback of many types of organic polymers is flammability which limits their suitability in applications requiring flammability resistance and where regulatory authorities govern flammability standards.

Although the addition of fire retardants to polymeric systems may improve their fire performance other important properties are often adversely effected for example: Mechanical performance Surface finish Durability Rheology Stability Smoke generation Toxicity Cost Recyclability

Furthermore, there has been considerable recent impetus to reduce the use of some flame-retardant classes due to toxicological or environmental concerns.

Such legislation has placed pressure on the use of halogenated compounds and certain metal oxide synergists.

Phosphorus-based flame-retardants such as phosphonates and elemental (red) phosphorus are also undesirable due to their regulation under chemical weapon acts and considerable manufacturing danger.

However, such compositions are undesirable due to the danger associated with handling of elemental phosphorus.

Clearly any use of halogenated flame retardant is undesirable.

In many polymeric systems, however, this flame retarding system is undesirable since they require moulding or forming at temperatures between 100° C. to 150° C. Inoue and Hosokawa (JP 10081510 (1998) Showa Denko K.K.) investigated the use of fluorinated synthetic mica exchanged with melamine (0.1-40%) and melamine salts (<10%) as a means of flame proofing plastics in a two step extrusion process.

The use of synthetic clays and multiple step processing is clearly undesirable from a commercial viewpoint.

Inoue and Hosokawa do not disclose highly desirable chemistries and methodologies associated with triazine based formulations which effect mechanical and fire performance.

Furthermore, they do not disclose important methodologies to flame retarded thin parts known by those in the art to be extremely difficult to render flame resistant whilst simultaneously reducing toxic gas and smoke generation during combustion.

The poor rheological properties of highly rigid polyamide formulations limit the inventions usefulness in preparing components made by conventional processing techniques such as rotational or blow moulding, that are complex or thin walled or which require high ductility or impact performance.

Images