Coating processes – With post-treatment of coating or coating material – Heating or drying
Reexamination Certificate
2000-09-12
2003-04-01
Green, Anthony J. (Department: 1755)
Coating processes
With post-treatment of coating or coating material
Heating or drying
C106S018150, C252S008610, C252S608000, C427S419800
Reexamination Certificate
active
06541068
ABSTRACT:
FIELD OF TECHNOLOGY
The invention relates to a technology for producing polymer materials, including textiles, with reduced combustibility, low toxicity of the gases given off during combustion and low smoke-forming capability.
Chemical fibres and textile materials are used in various industries, including for making composition materials used in road transport and in aircraft and ship building. Woven and knitted fabrics are used as decorative finishing materials in places where people are present in large numbers (theatres, clubs, hospitals, museums and hotels), in the building industry and in transport.
Textile materials are widely used in everyday life and for making special clothing for workers in practically every industry.
At the same time, the easy flammability and combustibility of most industrially produced chemical fibres and textile materials constitute a significant problem. They have a low spontaneous combustion temperature and a high burning rate.
PRIOR ART
A method of fire protection impregnation based on the use of orthophosphoric acid and compounds containing nitrogen (dicyanodiamide, carbamide, melamine, guanidine etc.) is widely used on an industrial scale in Russia. In this method, the fabric is treated with a composition including phosphoric acid and one of the listed
nitrogen-containing compounds and is subjected to heat treatment (Ye. A. Blekhman, The Manufacture of Incombustible Cotton Fabrics, Moscow, 1950-189 pp.). This process has considerable faults, namely a marked reduction in the resistance of the fabric to tearing load (a reduction in tearing strength of 40-50%) and low efficiency of the fire resistance effect for fabrics composed of a mixture of synthetic and cellulose fibres.
There is a known fire protection composition (GB application 2273720) for the treatment of fabrics, non-woven materials and carpet products, consisting of an aqueous solution of inorganic salts (ammonium phosphate, ammonium sulphate, ammonium bromide and mixtures of these in quantity 12-20% of the composition) and mineral acid (sulfuric acid-—0.4-0.6 wt. % of the composition), which assists the solution in penetrating into the fibres of the material and which raises the stability of the bonding of the combustion retarder with the fibres of the textile material. A fault of this composition is the low efficiency of the fire protection effect for materials containing synthetic fibres.
The compositions FR Cros 282, 330 and 334, based on ammonium polyphosphates (Catalogue of Combustion Retarders, Bolid GmbH, Frankfurt, 1996), are used for the fire protection of textiles. The composition FR Cros 282 includes modified mono ammonium phosphate with 10% ammonium polyphosphate in combination with melamine and pentaerythritol in the ratio 3:1:1. The concentration of this composition in the aqueous suspension used for the treatment of textiles is 500 g/liter.
The composition FR Cros 330 is an aqueous vinyl acetate suspension with ammonium polyphosphate, in which the content of the solid matter is 50%. The composition FR Cros 334 includes modified ammonium pyrophosphate. It is used for the fire protection of wood, paper and textiles. For all these compositions, the fire protection effect is achieved with the introduction of combustion retarders into the material in quantity 30-40%, which leads to a reduction in the physico-mechanical indicators and feel properties of the fabrics.
There is a known fire protection process for cellulose materials, based on the use of tetra-(hydroxymethyl)-phosphonium chloride (THPC) and polyfunctional compounds containing nitrogen, which has been given the name “Proban” (U.S. Pat. No. 2,912,466). To make cellulose materials fire-resistant by this process, a polycondensation process is first carried out between THPC and carbamide at a molar ratio of the components of 1:1. The cellulose material is impregnated with an aqueous solution of the precondensate and dried.
The formation of a polymer insoluble in water and organic solvents is achieved by treating the material with ammonia solution or gaseous ammonia at 140-160° C. This treatment is called “Probanfinish-210”. The problems with this method include a reduction in the strength of the fabric by 30% and an increase in the stiffness of the material. There are also data indicating high toxicity of the combustion products from cellulose materials containing THPC. When thermolysis of the fire-protected cellulose takes place in the 200-300° C. range, the emission of phosphatin is observed (Spect. Chem., 1984, V. 4, pp. 17-20).
The most effective treatment for cellulose fabrics and for fabrics made of a mixture of cellulose and synthetic fibres is one called “Pyrovatex-CP” (Technico-economic Information Bulletin on Light Industry, 1975, No. 9, pp. 75-76). The fabric is impregnated with an aqueous solution containing N-hydroxymethyldi-(methoxy)-phosphonopropionamide, carbamide, a cross-linking agent and a catalyst. It is then dried, heat-stabilised at a temperature of 140-160° C. and washed. When cotton fabrics are treated by the “Pyrovatex-CP” method, the fire-resistant properties are achieved at a content of 2.0% of phosphorus in the material.
The toxicity of the pyrolysis products of the materials is a significant problem for fabrics protected against fire by the use of N-hydroxymethyldi-(methoxy)-phosphono-propionamide. It has been shown (Textilveredelung, 1970, V. 6, pp. 486-497) that at a temperature of 300-400° C., considerable quantities of methanol are emitted. The relationship revealed rules out the use of fabrics fire-protected in this way for making special clothing for workers and also for the fireproofing of materials used in enclosed spaces.
A study of the comparative effectiveness of the phosphorus-containing preparations “Proban” and “Pyrovatex-CP” has shown that their effectiveness is different for cotton fabrics and fabrics made of a mixture of cotton and polyester fibres.
In all the studied variants of the treatment of fabrics made of a mixture of fibres by the “Pyrovatex-CP” method, the materials had higher fire protection indicators. However, in both cases, fire-protected fabrics can only be produced if they contain not more than 10% of synthetic fibre (Text. Res. J., V. 45, No. 8, p. 586).
The main problem with the known “Proban” and “Pyrovatex-CP” processes is their low effectiveness for materials made of a mixture of cellulose and synthetic fibres and pure synthetic fibres.
UK Patent 2205868 for the fire protection treatment of fabrics based on cellulose with other fibres proposes carrying out the “Proban” method treatment at least twice, and also oxidising the phosphorus into the pentavalent form by treating the fabric dried out after the first or second treatment with a solution of hydrogen peroxide.
U.S. Pat. No. 4,732,789 proposes a two-stage process of treating fabrics made of a mixture of cotton with polyester or nylon. The fabric is initially treated by the “Proban” method, after which hexabromocyclododecane or cyclic phosphonates are used to provide fire protection for the polyester or nylon components. The treated fabric is vulcanised, and if hexabromocyclododecane is used, it is heated to above 182° C. to melt the fireproofing compound. The two-stage nature of the process and the requirement for vulcanisation at high temperatures makes it very difficult for this invention to be applied in practice.
A preparation called “Pyrofix”, based on dialkyl phosphonamide of carbonic acid (Catalogue of Chemical Products, JSC “Ivkhimprom”, 1995, pp. 22-23), has been proposed for imparting fire protection properties to textile materials containing cellulose.
To impart fire protection properties, it is recommended that the impregnating solution should contain the following (g/liter):
pyrofix
350-400,
metazine 6Y
60-80,
polyethylene emulsion
20-30,
orthophosphoric acid
10.
The problem with this preparation is the low efficiency of the fireproofing effect for fabrics made of a mixture of cellulose and synthetic fibres.
USSR Authorship Certificate No. 1427017 describes a fire protection treatm
Berlin Alexandr Alexandrovich
Butylkina Nataliya Grigorievna
Galbraikh Leonid Semenovich
Khalturinsky Nikolai Alexandrovich
Zubkova Nina Sergeevna
Green Anthony J.
Isle Firestop Limited
Pittenger, P.C. James E.
LandOfFree
Method for the flame-retardant processing of textile materials does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for the flame-retardant processing of textile materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for the flame-retardant processing of textile materials will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3086076