Formaldehyde-free sizing composition for fibres, in particular mineral fibres, and resulting products

Abstract

A formaldehyde-free sizing composition for products based on fibers, in particular mineral fibers, such as glass or rock fibers, which includes: at least one non-reducing sugar, at least one catalyst for the dehydration of the non-reducing sugar, at least one amine, and at least one compound including activated ethylenic unsaturation(s).

Claims

1. Formaldehyde-free sizing composition for fibres, comprising: at least one non-reducing sugar, at least one inorganic dehydration catalyst for the dehydration of the non-reducing sugar, wherein the at least one inorganic dehydration catalyst is selected from the group consisting of a sulphate of a transition metal, a sulphate of a poor metal, an ammonium sulphate, and any mixture thereof, at least one amine, and at least one compound comprising activated ethylenic unsaturation(s), wherein the compound comprising activated ethylenic unsaturation(s) corresponds to the following formula (IV): ##STR00004## in which: R.sub.3 represents a hydrogen atom, a C.sub.1-C.sub.5 alkyl group, a hydroxyl group or a C.sub.1-C.sub.5 alkoxy group, R.sub.4 and R.sub.5, which are identical or different, represent a hydrogen atom, a C.sub.1-C.sub.5 alkyl group or a COR.sub.3 group, and R.sub.6 represents a hydrogen atom or a hydrocarbon chain which can include one or more heteroatoms.

2. Composition according to claim 1, wherein the non-reducing sugar is an oligosaccharide including at most 10 saccharide units.

3. Composition according to claim 2, wherein the non-reducing sugar is a di-, tri-, tetra- or pentasaccharide.

4. Composition according to claim 1, wherein the non-reducing sugar is trehalose, isotrehaloses, sucrose, melezitose, gentianose, raffinose, erlose, umbelliferose, stachyose or verbascose.

5. Composition according to claim 1, wherein the amount of inorganic dehydration catalyst for the dehydration of the non-reducing sugar represents from 1 to 30% of the weight of the non-reducing sugar.

6. Composition according to claim 1, wherein the amine corresponds to the following formula (I):
R-A-NHR.sub.1(I) in which: R is equal to H, OH, NHR.sub.1 or NR.sub.1, A represents an optionally branched alkylene, arylalkylene, arylene or alkylarylene group, a CO group or a group of following formula (II): ##STR00005## in which: X is equal to O or NR.sub.2 with R.sub.2 equal to H, (CH.sub.2).sub.zNH.sub.2 or a divalent (CH.sub.2).sub.t group which forms, with a neighbouring nitrogen atom, a ring comprising 6 atoms, x, y, z and t vary from 1 to 5, n is equal to 1, 2, 3 or 4, R.sub.1 is a hydrogen atom or a C.sub.1 to C.sub.5 hydroxyalkyl group.

7. Composition according to claim 6, wherein the amine is selected from the group consisting of monoethanolamine, diethanolamine, urea, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), aminoethyltriethylenetetramine (AETETA), N-(aminoethyl)tetraethylenepentamine and N-(aminoethyl)tetraethylenepentamine (AETEPA), bis(piperazine)ethylene (BISPIP), aminoethyl piperazinylethylethylenediamine (AEPEEDA), piperazinylethyldiethylenetriamine (PEDETA), aminoethylpiperazinylethyldiethylenetriamine (AEPEDETA), piperazinylethyltriethylenetetramine (PETETA), tris(aminoethyl)aminoethylpiperazine (TRISAEAEP) and piperazinylethylaminoethyldiethylenetriamine (PEAEDETA).

8. Composition according to claim 7, wherein the amine is urea, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and the mixtures of abovementioned amines in which TEPA is predominant.

9. Composition according to claim 1, wherein the compound is acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, citraconic acid, itaconic acid and the anhydrides of these acids.

10. Composition according to claim 1, wherein the amount of amine in the composition is such that the molar ratio of the compound comprising activated ethylenic unsaturation(s) to the amine varies from 1 to 3.5.

11. Composition according to claim 1, wherein the amount of compound comprising activated ethylenic unsaturation(s) in the composition is such that the molar ratio of the compound comprising activated ethylenic unsaturation(s) to the sum of the constituent saccharide units of the non-reducing sugar varies from 0.05 to 1.5.

12. Composition according to claim 1, further comprising the additives below in the following proportions, calculated on the basis of 100 parts by weight of non-reducing sugar, inorganic dehydration catalyst for the non-reducing sugar, amine and compound comprising activated ethylenic unsaturation(s): from 0 to 2 parts of silane, from 0 to 20 parts of oil, from 0 to 5 parts of a silicone, from 0 to 30 parts of an extender.

13. Process for the manufacture of an acoustic and/or thermal insulating product, the process comprising: manufacturing a mineral wool or mineral fibres, applying a sizing composition to said wool or said fibres, and treating said wool or said fibres at a temperature which makes possible the crosslinking of the size and the formation of an infusible binder, wherein the sizing composition is a formaldehyde-free sizing composition, comprising at least one non-reducing sugar, at least one inorganic dehydration catalyst for the dehydration of the non-reducing sugar, wherein the at least one inorganic dehydration catalyst is selected from the group consisting of a sulphate of a transition metal, a sulphate of a poor metal, an ammonium sulphate, and any mixture thereof, at least one amine, and at least one compound comprising activated ethylenic unsaturation(s), wherein the compound comprising activated ethylenic unsaturation(s) corresponds to the following formula (IV): ##STR00006## in which: R.sub.3 represents a hydrogen atom, a C.sub.1-C.sub.5 alkyl group, a hydroxyl group or a C.sub.1-C.sub.5 alkoxy group, R.sub.4 and R.sub.5, which are identical or different, represent a hydrogen atom, a C.sub.1-C.sub.5 alkyl group or a COR.sub.3 group, and R.sub.6 represents a hydrogen atom or a hydrocarbon chain which can include one or more heteroatoms.

14. Process according to claim 13, wherein the non-reducing sugar is an oligosaccharide including at most 10 saccharide units.

15. Process according to claim 14, wherein the non-reducing sugar is a di-, tri-, tetra- or pentasaccharide.

16. Process according to claim 13, wherein the non-reducing sugar is trehalose, isotrehaloses, sucrose, melezitose, gentianose, raffinose, erlose, umbelliferose, stachyose or verbascose.

17. Process according to claim 13, wherein the amount of inorganic dehydration catalyst for the dehydration of the non-reducing sugar represents from 1 to 30% of the weight of the non-reducing sugar.

18. Process according to claim 13, wherein the amine corresponds to the following formula (I):
R-A-NHR.sub.1(I) in which: R is equal to H, OH, NHR.sub.1 or NR.sub.1, A represents an optionally branched alkylene, arylalkylene, arylene or alkylarylene group, a CO group or a group of following formula (II): ##STR00007## in which: X is equal to O or NR.sub.2 with R.sub.2 equal to H, (CH.sub.2).sub.zNH.sub.2 or a divalent (CH.sub.2).sup.t group which forms, with a neighbouring nitrogen atom, a ring comprising 6 atoms, x, y, z and t vary from 1 to 5, n is equal to 1, 2, 3 or 4, R.sub.1 is a hydrogen atom or a C.sub.1 to C.sub.5 hydroxyalkyl group.

19. Process according to claim 17, wherein the amine is selected from the group consisting of monoethanolamine, diethanolamine, urea, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), aminoethyltriethylenetetramine (AETETA), N-(aminoethyl)tetraethylenepentamine and N-(aminoethyl)tetraethylenepentamine (AETEPA), bis(piperazine)ethylene (BISPIP), aminoethylpiperazinylethylethylenediamine (AEPEEDA), piperazinylethyldiethylenetriamine (PEDETA), aminoethylpiperazinylethyldiethylenetriamine (AEPEDETA), piperazinylethyltriethylenetetramine (PETETA), tris(aminoethyl)aminoethylpiperazine (TRISAEAEP) and piperazinylethylaminoethyldiethylenetriamine (PEAEDETA).

20. Process according to claim 13, wherein the compound is acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, citraconic acid, itaconic acid and the anhydrides of these acids.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 represents the curve of variation in the modulus of elasticity E (in MPa) as a function of the temperature (in C.).

(2) The following examples make it possible to illustrate the invention without, however, limiting it.

(3) In these examples, the following are measured: the crosslinking start temperature (T.sub.C) by the Dynamic Mechanical Analysis (DMA) method, which makes it possible to characterize the viscoelastic behaviour of a polymeric material. The procedure is as follows: a sample of Whatman paper is impregnated with the sizing composition (content of organic solids of the order of 30%) and is then fixed horizontally between two jaws. An oscillating component equipped with a device for measuring the stress as a function of the strain applied is positioned on the upper face of the sample. The device makes it possible to calculate the modulus of elasticity E. The sample is heated to a temperature varying from 20 to 250 C. at the rate of 4 C./min. The curve of variation in the modulus of elasticity E (in MPa) as a function of the temperature (in C.) is plotted from the measurements, the general appearance of the curve being given in FIG. 1. The value of the crosslinking start temperature (T.sub.C), in C., is determined on the curve. the tensile strength according to Standard ASTM C 686-71T on a sample cut out by stamping from the insulating product. The sample has the shape of a torus with a length of 122 mm, a width of 46 mm, a radius of curvature of the cut-out of the outer edge equal to 38 mm and a radius of curvature of the cut-out of the inner edge equal to 12.5 mm.

(4) The sample is positioned between two cylindrical mandrels of a test machine, one of which is movable and is moved at a constant rate. The breaking force F (in newtons) of the sample is measured and the tensile strength TS, defined by the ratio of the breaking force F to the weight of the sample, is calculated (N/g).

(5) The tensile strength is measured after manufacture (initial tensile strength) and after accelerated ageing in an autoclave at a temperature of 105 C. under 100% relative humidity for 15 minutes (TS 15). the initial thickness of the insulating product and the thickness after compressing for 1 hour and 30 days with a degree of compression (defined as being the ratio of the nominal thickness to the thickness under compression) equal to 4.8/1. The thickness measurements make it possible to evaluate the dimensional behaviour of the product. the thermal conductivity coefficient according to Standard EN 13162, expressed in W/(mK). the tear strength according to Standard NF EN 1607, expressed in kPa, the compressive strength according to Standard EN 826, expressed in kPa.

EXAMPLES 1 TO 11

(6) Sizing compositions are prepared which comprise the constituents appearing in Table 1, expressed as parts by weight:

(7) a) the compound comprising activated ethylenic unsaturation(s) and the amine are mixed beforehand in a first container and the mixture is left at a temperature of the order of 20 to 25 C. for 15 minutes,

(8) b) the sizing compositions are prepared by introducing, into a second container containing water, the non-reducing sugar, the dehydrating catalyst and the mixture obtained in a) with stirring until the constituents are completely dissolved.

(9) The performance of a sizing composition comprising 82 parts by weight of a phenol-formaldehyde-monoethanolamine resin (Example 1 of WO 2008/043960) and 20 parts by weight of urea (Ref.) is also shown in Table 1.

(10) Examples 4, 6 and 9 exhibit lower crosslinking start temperatures than the reference. However, the highest crosslinking start temperatures (Examples 1, 7 and 8) remain acceptable.

(11) Ammonium sulphate (Example 9) makes it possible to reduce the crosslinking start temperature more effectively than copper sulphate (Example 1), aluminium sulphate (Example 7) or iron(II) sulphate (Example 8).

EXAMPLES 12 TO 18

(12) These examples illustrate the manufacture of insulating products on an industrial line.

(13) The sizing compositions of Examples 1 to 3 and 8 and the reference size (Ref.) are used to form products based on mineral wool exhibiting a nominal density equal to 17.5 kg/m.sup.3 and a thickness equal to 75 mm. The content of binder (crosslinked size) represents 4.7% by weight of the product.

(14) Sizing compositions 4M and 6M, having the compositions given in Examples 4 and 6 respectively modified in that the copper sulphate is replaced by ammonium sulphate, are also used.

(15) Glass wool is manufactured on a pilot-scale line by the internal centrifugation technique in which the molten glass composition is converted into fibres by means of a tool, referred to as centrifuging disc, comprising a basket forming a chamber for receiving the molten composition and a peripheral band pierced by a multitude of orifices: the disc is rotated about its vertically positioned axis of symmetry, the composition is ejected through the orifices under the effect of the centrifugal force and the material escaping from the orifices is drawn into fibres with the assistance of a drawing gas stream.

(16) Conventionally, a size spraying ring is positioned beneath the fiberizing disc so as to uniformly distribute the sizing composition over the glass wool which has just been formed.

(17) The mineral wool, thus sized, is collected on a belt conveyor with a width of 2.4 m equipped with internal extraction boxes which hold the mineral wool in the form of a web at the surface of the conveyor. The web passes continuously through an oven maintained at 270 C., where the constituents of the size polymerize to form a binder. The amount of binder represents 4.7% by weight of the final insulating product.

(18) The properties of the insulating products appear in Table 2.

(19) The products using ammonium sulphate (Examples 16 and 17) have the best properties.

(20) The product of Example 16 is comparable to that of the reference.

EXAMPLES 19 TO 23

(21) These examples illustrate the manufacture of other insulating products on a pilot-scale line.

(22) The sizing compositions of Examples 4 to 6 and 4M and the reference size (Ref.) are used to form products exhibiting a nominal density equal to 10.6 kg/m.sup.3 and a thickness of 144 mm. The content of binder (crosslinked size) represents 4.7% by weight of the product.

(23) The mineral wool is obtained under the conditions described in Examples 12 to 18 modified in that the sized mineral wool is cut up before being introduced into an oven at 210 C. for 5 minutes and then the mineral wool is again placed in the oven, after having been turned upside down, for an additional 5 minutes.

(24) The properties of the insulating products appear in the following Table 3.

(25) TABLE-US-00001 TABLE 3 Example 19 20 21 22 23 Sizing composition Ex. 4 Ex. 5 Ex. 6 4M Ref. Properties Tensile strength (N/g) Initial 2.7 2.4 2.5 2.9 3.7 After ageing (TS 15) 2.3 2.2 2.0 2.9 3.4 Thickness (mm) After 1 hour 129.7 139.1 133.8 141.4 140.8 After 30 days 98.3 n.d. 96.5 101.0 107.3 (W/(m K)) 0.033 0.033 0.033 0.033 0.034 n.d.: not determined

(26) The product using ammonium sulphate (Example 22) has better properties than that using copper sulphate (Example 19).

EXAMPLES 24 AND 25

(27) These examples illustrate the manufacture on an industrial line of insulating products based on rock wool.

(28) The insulating product is manufactured by the free centrifuging technique, in which the rock, in the molten state, is conveyed to the periphery of centrifuging wheels (three or four) and is entrained by these wheels in such a way that a portion of the molten rock is detached therefrom and is converted into fibres under the effect of the centrifugal force. The remaining unconverted portion is conveyed to another wheel or, after the final wheel, falls to the ground in the form of shot. A stream of air at the periphery of the centrifuging wheels makes it possible to assist in the formation of the fibres by a drawing effect, to pick up the fiberized material, separating it from the non-fiberized material (shot), and to convey the fiberized material to a conveyor belt equipped with extraction boxes which transports the fibres downstream of the line to a lapper and an oven for polymerizing the sizing composition and for conditioning the product.

(29) The final product has a density equal to 90 kg/m.sup.3, a thickness equal to 52 mm and a content of binder representing 2.5% of the product.

(30) The product of Example 23 uses the sizing composition according to Example 4 and the product of Example 24 uses the reference composition (Ref.).

(31) The properties of the insulating products appear below:

(32) TABLE-US-00002 Ex. 25 Ex. 24 (comparative) Tear strength (kPa) 4.0 4.9 Compressive strength (kPa) 13.3 14.6

(33) TABLE-US-00003 TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 11 Ref. Sizing composition Sucrose 61.0 76.0 85.5 57.0 68.0 76.6 61.0 61.0 61.0 68.0 76.6 Copper sulphate 3.0 4.0 4.5 10.0 12.0 13.4 Aluminium sulphate 3.0 Iron(II) sulphate 3.0 12.0 13.4 Ammonium sulphate 3.0 Tetraethylenepentamine (TEPA).sup.(1) 17.6 9.8 4.9 16.2 9.8 4.9 17.6 17.6 17.6 9.8 4.9 Maleic anhydride 18.4 10.2 5.1 16.8 10.2 5.1 18.4 18.4 18.4 10.2 5.1 Properties Crosslinking start temp. T.sub.c ( C.) 175 169 162 149 157 143 177 175 129 167 164 151 pH.sup.(2) 4.2 3.6 3.5 n.d. n.d. n.d. 5.2 4.9 5.7 n.d. n.d. 6.0 .sup.(1)Sold by Huntsman (mixture of TEPA (predominant), AETETA, AEPEEDA, PEDETA and BISPIP) .sup.(2)Solids content: 30% n.d.: not determined

(34) TABLE-US-00004 TABLE 2 Example 18 12 13 14 15 16 17 (comparative) Sizing composition Ex. 1 Ex. 4 Ex. 6 Ex. 8 4M 6M Ref. Properties Tensile strength (N/g) Initial 3.8 3.8 3.4 3.7 4.1 3.8 4.3 After ageing (TS 15) 3.8 3.2 2.8 3.6 3.9 3.6 3.8 Thickness (mm) After 1 hour 78.1 79.3 80.4 78.9 79.7 79.8 82.5 After 30 days 75.3 70.7 73.0 75.0 70.5 71.0 77.2 (W/(m K)) 0.033 0.034 0.033 0.033 0.032 0.033 0.034