BINDER FOR MINERAL FIBRES, COMPRISING LIGNOSULFONATE AND A CARBONYL COMPOUND, AND RESULTING MATS

Abstract

An aqueous binder for mineral fibers, in particular glass fibers, includes at least one ammonium lignosulfonate or one alkali metal or alkaline earth metal salt of lignosulfonic acid, and at least one carbonyl compound of formula: R—[C(O)R.sub.1].sub.x (I) in which: R represents a saturated or unsaturated and linear, branched or cyclic hydrocarbon radical, a radical including one or more aromatic nuclei which consist of 5 or 6 carbon atoms, a radical including one or more aromatic heterocycles containing 4 or 5 carbon atoms and an oxygen, nitrogen or sulfur atom, it being possible for the R radical to contain other functional groups, in particular hydroxyl or alkoxy groups, especially methoxy groups, R.sub.1 represents a hydrogen atom or a C.sub.1-C.sub.10 alkyl radical, and x varies 1 to 10, the binder being devoid of hydrogenated sugar and of melamine.

Claims

1. An aqueous binder for mineral fibers, comprising: at least one ammonium lignosulfonate or one alkali metal or alkaline earth metal salt of lignosulfonic acid, and at least one carbonyl compound of formula:
R—[C(O)R.sub.1].sub.x  (I) in which: R represents a saturated or unsaturated and linear, branched or cyclic hydrocarbon radical, a radical including one or more aromatic nuclei which consist of 5 or 6 carbon atoms, a radical including one or more aromatic heterocycles containing 4 or 5 carbon atoms and an oxygen, nitrogen or sulfur atom, it being possible for the R radical to contain other functional groups, R.sub.1 represents a hydrogen atom or a C.sub.1-C.sub.10 alkyl radical, and x varies from 1 to 10, said binder being devoid of hydrogenated sugar and of melamine.

2. The binder as claimed in claim 1, wherein R.sub.1 represents a hydrogen atom and x is at most equal to 6.

3. The binder as claimed in claim 2, wherein the carbonyl functional group is provided in the form of an acetal or of a hemiacetal of following formula (II): ##STR00004## in which: R.sub.2 represents a C.sub.1-C.sub.10 alkyl radical, and R.sub.3 represents a hydrogen atom or a C.sub.1-C.sub.10 alkyl radical.

4. The binder as claimed in claim 2, wherein the carbonyl compound is chosen from the group consisting of acetaldehyde, propionaldehyde, dimethoxyethanal, butyraldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, 2-hydroxyglutaraldehyde, 3-methylglutaraldehyde, adipaldehyde, suberaldehyde, sebacaldehyde, malealdehyde, fumaraldehyde, poly(acroleins), dialdehyde starch, furfural (2-furancarboxyaldehyde), 5-methylfurfural (2-methyl-5-furancarboxyaldehyde), hydroxymethylfurfural (2-hydroxymethyl-5-furancarboxyaldehyde), 2,5-furancarboxydialdehyde, vanillin and vanillin polymers, cinnamaldehyde and cinnamaldehyde polymers, phthalaldehyde, isophthalaldehyde, terephthalaldehyde and the oligomers of following formulae (III) and (IV): ##STR00005## in which: A represents a divalent —CH.sub.2—, —CH(OH)— or —CH.sub.2—O—CH.sub.2— radical, n varies from 1 to 8, ##STR00006## in which n′ varies from 1 to 9.

5. The binder as claimed in claim 1, wherein the ammonium lignosulfonate or the alkali metal or alkaline earth metal salt of lignosulfonic acid represents from 30 to 95% of the weight of the mixture consisting of ammonium lignosulfonate or the alkali metal or alkaline earth metal salt of lignosulfonic acid and the carbonyl compound of formula (I).

6. The binder as claimed in claim 1, further comprising: at least one vinyl acetate homopolymer or one copolymer of vinyl acetate and of at least one hydrophobic monomer, and at least one polysaccharide.

7. The binder as claimed in claim 6, wherein the homopolymer or copolymer of vinyl acetate and of at least one hydrophobic monomer is present in an amount at most equal to 15 parts by weight per 100 parts by weight of ammonium lignosulfonate or of alkali metal or alkaline earth metal salt of lignosulfonic acid and of carbonyl compound of formula (I).

8. The binder as claimed in claim 6, wherein the polysaccharide is present in an amount at most equal to 50 parts by weight per 100 parts by weight of ammonium lignosulfonate or of alkali metal or alkaline earth metal salt of lignosulfonic acid and of carbonyl compound of formula (I).

9. The binder as claimed in claim 1, further comprising an ammonium lignosulfonate and at least one compound chosen from phosphorus-containing compounds and ammonium sulfate.

10. The binder as claimed in claim 9, wherein the phosphorus-containing compound and the ammonium sulfate are present in an amount at most equal to 20 parts by weight per 100 parts by weight of ammonium lignosulfonate and of carbonyl compound of formula (I).

11. The binder as claimed in claim 1, further comprising the additives below in the following proportions, calculated on the basis of 100 parts by weight of ammonium lignosulfonate or of alkali metal or alkaline earth metal salt of lignosulfonic acid and of carbonyl compound of formula (I): 0 to 1 part by weight of silane, 0 to 5 parts by weight of a silicone, of a vegetable oil or of a fluorinated compound, and 0 to 5 parts of a plasticizing agent.

12. The binder as claimed in claim 1, further comprising an alkali metal or alkaline earth metal salt of lignosulfonic acid and wherein the binder is devoid of nitrogenous compounds.

13. A mat comprising mineral fibers, wherein the fibers are bonded by the binder as claimed in claim 1.

14. The mat as claimed in claim 13, wherein the mat exhibits a weight per unit area which varies from 10 to 1100 g/m.sup.2.

15. The mat as claimed in claim 13, wherein the binder represents from 5 to 40% by weight of said mat.

16. The mat as claimed in claim 13, comprising organic fibers in a proportion at most equal to 20% of the weight of the mineral fibers.

17. The binder as claimed in claim 1, wherein the mineral fibers are rock or glass fibers.

18. The binder as claimed in claim 1, wherein the other functional groups include hydroxyl or alkoxy groups.

19. The binder as claimed in claim 18, wherein the other functional groups include methoxy groups.

20. The binder as claimed in claim 4, wherein the carbonyl compound is n-butyraldehyde or bis-vanillin.

21. The binder as claimed in claim 5, wherein the ammonium lignosulfonate or the alkali metal or alkaline earth metal salt of lignosulfonic acid represents from 40 to 80% of the weight of the mixture consisting of ammonium lignosulfonate or the alkali metal or alkaline earth metal salt of lignosulfonic acid and the carbonyl compound of formula (I).

22. The binder as claimed in claim 21, wherein the ammonium lignosulfonate or the alkali metal or alkaline earth metal salt of lignosulfonic acid represents from 50 to 70% of the weight of the mixture consisting of ammonium lignosulfonate or the alkali metal or alkaline earth metal salt of lignosulfonic acid and the carbonyl compound of formula (I).

23. The binder as claimed in claim 11, comprising 0.1 to 0.5 part by weight of silane, and 0.1 to 1 part by weight of a silicone, of a vegetable oil or of a fluorinated compound, wherein the plasticizing agent is glycerol.

24. The mat as claimed in claim 13, wherein the mineral fibers are rock or glass fibers.

25. The mat as claimed in claim 14, wherein the mat exhibits a weight per unit area which varies from 30 to 350 g/m.sup.2.

26. The mat as claimed in claim 25, wherein the mat exhibits a weight per unit area which varies from 35 to 75 g/m.sup.2.

27. The mat as claimed in claim 15, wherein the binder represents from 10 to 30% by weight of said mat.

Description

EXAMPLES 1 TO 6

[0078] Aqueous binders comprising the constituents appearing in table 1 in proportions expressed as parts by weight of solids are prepared. The reference binder (denoted Ref.) is representative of the state of the art described in WO 2012/172252.

[0079] The binders are prepared by introducing the different constituents into a container containing water at ambient temperature, with moderate stirring.

[0080] The solids content (dry matter) of the binders is equal to 20%.

[0081] Use is made of a mat of filaments of glass E having a diameter of 13 μm and a length of 18 mm. The weight per unit area of the mat is equal to 75 g/m.sup.2.

[0082] The mat is immersed in the binder for 30 seconds and then the excess is removed by suction. The mat is subsequently treated in a drying oven at 210° C. for 60 seconds. In the end, the mat contains 20% by weight of binder.

[0083] The properties of each mat are given in table 1.

[0084] Examples 1 to 3 have an initial breaking stress and a breaking stress after accelerated aging which are improved with respect to the Reference.

[0085] In addition, examples 2, 3 and 6 exhibit, after treatment with water, a better breaking stress with respect to the Reference.

TABLE-US-00001 TABLE 1 Ex. Ex. Ex. Ex. Ex. Ex. 1 2 3 4 5 6 Ref. Composition of the binder Ammonium lignosulfonate.sup.(1) 95 80 60 — — — 60 Sodium lignosulfonate.sup.(2) — — — 80  — — — Magnesium lignosulfonate.sup.(3) — — — — 80  — — Calcium lignosulfonate.sup.(4) — — — — — 80 — Hydroxymethylfurfural 5 20 40 20  20  20 — Glucose — — — — — — 40 Diammonium phosphate — — — — — —  5 Properties of the mat Breaking stress (N/5 cm) Initial 40 63 80 42  62  48 30 After accelerated aging (a) 48 61 77 2 3 41 27 % retention 121 98 96 5 5 86 90 After treatment with water (b) 0 14 33 0 0 29 11 % retention 0 22 41 0 0 60 37 .sup.(1)T11N5, sold by Tembec .sup.(2)Arbo N18, sold by Tembec .sup.(3)Arbo MGLS, sold by Tembec .sup.(4)C12, sold by Tembec