IL40626A

IL40626A - Non-woven articles based on heatresistant resin and process for preparing the same

Info

Publication number: IL40626A
Application number: IL40626A
Authority: IL
Original assignee: Rhone Poulenc Sa
Priority date: 1971-10-20
Filing date: 1972-10-19
Publication date: 1976-01-30
Also published as: IT969763B; JPS4853063A; DD98959A5; JPS5542173B2; CA995074A; LU66323A1; FR2156452A1; ATA897972A; FR2156452B1; BE790327A; AT326084B; ZA727331B; AU4780972A; CH542901A; NL7213813A; DE2251583A1; GB1400512A; IL40626A0; ES407810A1; BR7207269D0

Abstract

1400512 Non-woven fabrics RHONEPOULENC SA 19 Oct 1972 [20 Oct 1971] 48271/72 Headings D1R and D2B A non-woven fabric consists essentially of a web of fibres bonded to each other by a synthetic polymeric binder, the fibres being made of a material which is non-fusible or has a softening point above 180�C and the binder being obtained by reacting a N, N'-bisimide of an unsaturated dicarboxylic acid of the formula wherein D is a divalent organic radical containing a carbon-carbon double bond and A is a C 2-30 divalent organic radical, with a polyamine R(NH 2 ) x in which x is an integer at least equal to z and R is an organic radical of valency x, 0.55 to 25 mols of bis imide being present per molar-NH 2 group provided by the polamine, and being present in an amount from 5 to 150% by wt. based on the dry wt. of the fibres. The fibres may be of carbon, glass, aluminium oxide, zirconium oxide, asbestos, boron, copper or steel, or polyester, polyacrylonitrile, polytetrafluorothylene, a copolymer of tetrafluorotheylene and hexafluoropropylene, polyamide fibres e.g. wholly aromatic polyamide, or polyamide-imide fibres e.g. of the polytrimellamide-imide type. The polymeric binder may be present in the fabric either in the form of a pre-polymer or a completely cross-linked resin. The web may be formed by dry or wet laying techniques. The polymeric binder can be incorporated in the form of a powder or aqueous solution or dispersion before or after web formation. In a typical example, a polyimide prepolymer, obtained by heating a mixture of N, N'-4, 4'-diphenylmethane-bis-maleimide and bis(4-aminophenyl)methane, is mixed with aromatic polyamide fibres in water and a web is formed from the dispersion using a paper-making machine. The non-woven fabrics may be used for making filters, catalyst supports, and cores for electrical insulating linings. [GB1400512A]

Claims

1. WE CLAIM 10 A non-woven article consisting essentially of a web of fibres bonded to one another by a synthetic polymer, in which: a) the fibres are made of a material which is non-fusible or has a softening point above 180°C, b) the polymer binder is one obtained from a Ν,Ν* — bis-imide of an unsaturated dicarboxylic acid, of the general formul : in which D represents a divalent organic radical containing a carbon-carbon double bond and A represents a divalent organic radical containing 2 to 30 carbon atoms, and from a polyamine of the general formula: in which x is an integer at least equal to 2 and R represents an organic radical of valency x, 0.55 to 25 mols of bis-imide being present per molar -ΝΗ2 group provided by the polyamine, and c) the polymer binder is present in an amount from 5 to 150% by weight based on the dry weight of the fibres.

2. An article according to claim 1, in which the fibres are asbestos, glass or carbon fibres.

3. An article according to claim 1 in which the fibres are aromatic polyamide or polytrimellamide-imxde fibres„ - 26 -

4. An article according to any one of claims 1 to 3 in which D is a radical specifically identified herein.

5. An article according to any one of claims 1 to 4 in which A is a radical specifically identified herein.

6. An article according to any one of the preceding claims in which the bis-imide is N,N,-4,4'-diphenylmethane-bis-maleimide.

7. An article according to any one of the preceding claims in which the polyamine is a diprimary diamine of the general formula: in which E represents a divalent organic radical containing 2 to 30 carbon atoms.

8. An article according to claim 7 in which the polyamine is bis-(4-aminophenyl) -methane.

9. An article according to claim 7 or 8 in which the molar ratio of bis-imide to diamine is 2.5.

10. An article according to any one of the preceding claim3 in which the binder is produced by heating the bis-imide and the polyamine at between 50° and 250°C and has a softening point of between 50° and 200°C.

11. An article according to any one of claims 1 to 9 in which the binder is in the form of a non-fusible resin.

12. An article according to any one of the preceding claims in which the binder is present in an amount from 25 to 100% by weight based on the dry weight - 27 - of the fibres.

13. An article according to claim 1 substantially as hereinbefore described.

14. An article according to claim 1 substantially as described in any one of the Examples.

15. A process for producing an article as claimed in any one of the preceding claims which comprises forming a web of fibres, incorporating the binder, in the form of a powder of particle size between 20 and 250μ, into the we , and binding the fibres by melting the binder ,

16. A process for producing an article as claimed in any one of claims 1 to 14, which comprises mixing an aqueous dispersion of fibres and an aqueous 1 dispersion of binder in the form of a powder of particle 1 size between 20 and 250μ, forming a web by removing the water and then binding the fibres by melting the binder.

17. A process according to claim 15 or 16 in which the binder has a particle size between 40 and 160μ.

18. A process according to any one of claims 15 to 17 in which after melting the binder the article is stoved at a temperature of between 150° and 350°C.

19. A process according to claim 15 or 16 substantially as hereinbefore described.

20. A non-woven article whenever produced by a process as claimed in any one of claims 15 to 19.