INSULATION PRODUCTS

Abstract

The invention relates to a method of making an insulation product and a novel insulation product, wherein the insulation product is made by adhering a facing to at least one major surface of a batt of man-made vitreous fibres in a matrix comprising a binder by the use of an adhesive and curing the adhesive. The adhesive is an aqueous composition which is free of phenol and formaldehyde and comprises: a component (i) in form of one or more lignosulfonate lignins having a carboxylic acid group content of 0.03 to 2.0 mmol/g, such as 0.03 to 1.4 mmol/g, such as 0.075 to 2.0 mmol/g, such as 0.075 to 1.4 mmol/g, based on the dry weight of the lignosulfonate lignins, a component (ii) in form of one or more cross-linkers.

Claims

1. A method of making an insulation product, the method comprising: providing a batt of man-made vitreous fibres (MMVF) in a matrix comprising a binder, wherein the batt of man-made vitreous fibres comprises at least one major surface; providing a facing; fixing the facing to at least one major surface of the batt of man-made vitreous fibres by the use of an adhesive; and curing the adhesive, wherein the adhesive is an aqueous adhesive composition which is free of phenol and formaldehyde and comprises: a component (i) in form of one or more lignosulfonate lignins having a carboxylic acid group content of 0.03 to 2.0 mmol/g, such as 0.03 to 1.4 mmol/g, such as 0.075 to 2.0 mmol/g, such as 0.075 to 1.4 mmol/g, based on the dry weight of the lignosulfonate lignins, a component (ii) in form of one or more cross-linkers.

2. The method according to claim 1, wherein the facing is selected from woven or non-woven glass fibre veils or fabrics, scrims, rovings, glass fibre silks, glass filament fabrics, spunbonded polyester webs, vapour membranes, vapour barriers, roof underlay foils, aluminium foil and housewraps.

3. The method according to claim 1, wherein the facing is a non-woven glass veil having an area weight in the range of 30 to 150 g/m.sup.2.

4. The method according to claim 1, wherein the facing is a mineral coated non-woven glass veil having an area weight in the range of 150 to 350 g/m.sup.2.

5. The method according to claim 1, wherein the facing is a glass fibre silk or glass filament fabric having an area weight in the range of 90 to 180 g/m.sup.2.

6. The method according to claim 1, wherein the facing has at least one major surface and the method comprises applying adhesive to a major surface of the facing and/or the batt, and then applying said major surface of the facing to a major surface of the batt of man-made vitreous fibres.

7. The method according to claim 1, comprising applying the adhesive by spraying.

8. The method according to claim 1, wherein the step of curing the adhesive is carried out at a temperature of from 100 to 300 C., preferably 170 to 270 C., preferably 180 to 250 C., preferably 190 to 230 C.

9. The method according to claim 1, wherein the step of fixing the facing to at least one major surface of the batt is carried out when the binder for the MMVF is uncured, and the step of curing the adhesive also cures the binder in the matrix of MMVF.

10. The method according to claim 1, wherein the step of fixing the facing to at least one major surface of the batt is carried out after curing the binder for the MMVF.

11. The method according to claim 1, wherein the batt has a density in the range of 20 to 200 kg/m.sup.3.

12. The method according to claim 1, wherein the loss on ignition (LOI) of the batt of man-made vitreous fibres bonded by the binder is within the range of 0.5 to 8 wt %, preferably 2 to 5 wt %.

13. The method according to claim 1, wherein the insulation product has a thickness in the range of 20 to 400 mm.

14. The method according to claim 1, wherein the adhesive is applied in an amount of 40 to 400 g/m.sup.2, preferably 50 to 200 g/m.sup.2, more preferably 60 to 150 g/m.sup.2 of a liquid adhesive.

15. The method according to claim 1, wherein the method further comprises applying a coating to the facing after fixing the facing to the batt.

16. The method according to claim 1, wherein the insulation product is selected from the group consisting of an external faade, a ventilated faade, an interior ceiling insulation product, an interior wall insulation product, a roof insulation product, a ventilation duct or channel acoustic absorption product.

17. The method according to claim 1, wherein the binder in the batt of man-made vitreous fibres (MMVF) is a binder composition which prior to curing is an aqueous composition which is free of phenol and formaldehyde and comprises: a component (i) in form of one or more lignosulfonate lignins having a carboxylic acid group content of 0.03 to 2.0 mmol/g, such as 0.03 to 1.4 mmol/g, such as 0.075 to 2.0 mmol/g, such as 0.075 to 1.4 mmol/g, based on the dry weight of the lignosulfonate lignins, a component (ii) in form of one or more cross-linkers.

18. A method of making an insulation product, the method comprising: providing a batt of man-made vitreous fibres (MMVF) in a matrix comprising uncured binder, wherein the batt of man-made vitreous fibres comprises at least one major surface; providing a facing; applying the facing to at least one major surface of the batt of man-made vitreous fibres; and curing the binder so as to fix the facing to the major surface, wherein the binder is an aqueous binder composition which is free of phenol and formaldehyde and comprises: a component (i) in form of one or more lignosulfonate lignins having a carboxylic acid group content of 0.03 to 2.0 mmol/g, such as 0.03 to 1.4 mmol/g, such as 0.075 to 2.0 mmol/g, such as 0.075 to 1.4 mmol/g, based on the dry weight of the lignosulfonate lignins, a component (ii) in form of one or more cross-linkers.

19. A method according to claim 18, wherein the facing is selected from woven or non-woven glass fibre veils or fabrics, scrims, rovings, glass fibre silks, glass filament fabrics, spunbonded polyester webs, vapour membranes, vapour barriers, roof underlay foils, aluminium foil and housewraps.

20. The method according to claim 18, wherein the step of curing the binder is carried out at a temperature of from 100 to 300 C., preferably 170 to 270 C., preferably 180 to 250 C., preferably 190 to 230 C.

21. An insulation product obtained by the method according to claim 1.

22. An insulation product comprising an insulation element which is a batt of man-made vitreous fibres (MMVF) bonded with a binder, wherein the batt of man-made vitreous fibres comprises at least one major surface, and comprising a facing, wherein the facing is fixed to at least one major surface of the insulation element by an adhesive, wherein the adhesive before curing is an aqueous adhesive composition which is free of phenol and formaldehyde and comprises: a component (i) in form of one or more lignosulfonate lignins having a carboxylic acid group content of 0.03 to 2.0 mmol/g, such as 0.03 to 1.4 mmol/g, such as 0.075 to 2.0 mmol/g, such as 0.075 to 1.4 mmol/g, based on the dry weight of the lignosulfonate lignins, a component (ii) in form of one or more cross-linkers.

23. A product according to claim 22, the aqueous adhesive/binder composition further comprising a component (iii) in form of one or more plasticizers.

24. A product according to claim 22, wherein component (i) is having a carboxylic acid group content of 0.05 to 0.6 mmol/g, based on the dry weight of lignosulfonate lignins.

25. A product according to claim 22, wherein component (i) is in form of one or more lignosulfonate lignins having an average carboxylic acid group content of less than 1.8 groups per macromolecule considering the M_n wt. average of component (i), such as less than 1.4, such as less than 1.1, such as less than 0.7, such as less than 0.4.

26. A product according to claim 22, wherein component (i) is having a content of phenolic OH groups of 0.3 to 2.5 mmol/g, such as 0.5 to 2.0 mmol/g, such as 0.5 to 1.5 mmol/g. based on the dry weight of lignosulfonate lignins.

27. A product according to claim 22, wherein component (i) is having a content of aliphatic OH groups of 1.0 to 8.0 mmol/g, such as 1.5 to 6.0 mmol/g, such as 2.0 to 5.0 mmol/g, based on the dry weight of lignosulfonate lignins.

28. A product according to claim 22, wherein the component (i) comprises ammoniumlignosulfonates and/or calciumlignosulfonates, and/or magnesiumlignosulfonates, and any combinations thereof.

29. A product according to claim 22, wherein component (i) comprises ammoniumlignosulfonates and calciumlignosulfonates, wherein the molar ratio of NH.sub.4.sup.+ to Ca.sup.2+ is in the range of 5:1 to 1:5, in particular 3:1 to 1:3.

30. A product according to claim 22, wherein the aqueous adhesive/binder composition contains added sugar in an amount of 0 to less than 5 wt.-%, based on the weight of lignosulfonate and sugar.

31. A product according to claim 22, wherein the aqueous adhesive/binder composition comprises component (i) in an amount of 50 to 98 wt.-%, such as 65 to 98 wt.-%, such as 80 to 98 wt.-%, based on the dry weight of components (i) and (ii).

32. A product according to claim 22, wherein the component (ii) is in form of one or more cross-linkers selected from a. -hydroxyalkylamide-cross-linkers, and/or b oxazoline-cross-linkers, and/or c. the group consisting of multifunctional organic amines such as an alkanolamine, diamines, such as hexamethyldiamine, and/or d. epoxy compounds having a molecular weight of more than 500, such as an epoxidised oil based on fatty acid triglyceride or one or more flexible oligomer or polymer, such as a low Tg acrylic based polymer, such as a low Tg vinyl based polymer, such as low Tg polyether, which contains reactive functional groups such as carbodiimide groups, such as anhydride groups, such as oxazoline groups, such as amino groups, such as epoxy groups, and/or e. one or more cross-linkers selected from the group consisting of fatty amines; and/or f. one more cross-linkers in form of fatty amides; and/or g. one or more cross-linkers selected from polyester polyols, such as polycaprolactone; and/or h. one or more cross-linkers selected from the group consisting of starch, modified starch, CMC; and/or i. one or more cross-linkers in form of multifunctional carbodiimides, such as aliphatic multifunctional carbodiimides; and/or j. one or more cross-linkers selected from melamine based cross-linkers, such as a hexakis(methylmethoxy)melamine (HMMM) based cross-linkers.

33. A product according to claim 22, wherein the component (ii) comprises one or more cross-linkers selected from -hydroxyalkylamide-cross-linkers and/or oxazoline-cross-linkers.

34. A product according to claim 22, the adhesive/binder composition comprising component (ii) in an amount of 1 to 50 wt.-%, such as 4 to 20 wt.-%, such as 6 to 12 wt.-%, based on the dry weight of component (i).

35. A product according to claim 22, wherein the component (ii) is in form of one or more cross-linkers selected from a. -hydroxyalkylamide-cross-linkers, such as N-(2-hydroxyisopropyl)amide-cross-linkers, such as N-(2-hydroxyethyl)amide-cross-linkers, such as N-(2-hydroxyethyl)adipamide-cross-linkers, such as N,N,N,N-tetrakis(2-hydroxyethyl)adipamide and/or b. the group consisting of multifunctional organic amines such as an alkanolamine, diamines, such as hexamethyldiamine, and/or c. epoxy compounds having a molecular weight of more than 500, such as an epoxidised oil based on fatty acid triglyceride or one or more flexible oligomer or polymer, such as a low Tg acrylic based polymer, such as a low Tg vinyl based polymer, such as low Tg polyether, which contains reactive functional groups such as carbodiimide groups, such as anhydride groups, such as oxazoline groups, such as amino groups, such as epoxy groups, and/or d. one or more cross-linkers in form of multifunctional carbodiimides, such as aliphatic multifunctional carbodiimides.

36. A product according to claim 22, wherein the component (ii) comprises one or more cross-linkers selected from a. -hydroxyalkylamide-cross-linkers, such as N-(2-hydroxyisopropyl)amide-cross-linkers, such as N-(2-hydroxyethyl)amide-cross-linkers, such as N-(2-hydroxyethyl)adipamide-cross-linkers, such as N,N,N,N-tetrakis(2-hydroxyethyl)adipamide.

37. A product according to claim 22, the adhesive/binder composition comprising component (ii) in an amount of 2 to 90 wt.-%, such as 6 to 60 wt.-%, such as 10 to 40 wt.-%, such as 25 to 40 wt.-%, based on the dry weight of component (i).

38. A product according to claim 23, wherein component (iii) is in form of one or more plasticizers selected from the group consisting of fatty alcohols, monohydroxy alcohols, such as pentanol, stearyl alcohol; and/or one or more plasticizers selected from the group consisting of alkoxylates such as ethoxylates, such as butanol ethoxylates, such as butoxytriglycol; and/or one or more plasticizers in form of propylene glycols; and/or one or more plasticizers in form of glycol esters; and/or one or more plasticizers selected from the group consisting of adipates, acetates, benzoates, cyclobenzoates, citrates, stearates, sorbates, sebacates, azelates, butyrates, valerates; and/or one or more plasticizers selected from the group consisting of phenol derivatives, such as alkyl or aryl substituted phenols; and/or one or more plasticizers selected from the group consisting of silanols, siloxanes; and/or one or more plasticizers selected from the group consisting of sulfates such as alkyl sulfates, sulfonates such as alkyl aryl sulfonates such as alkyl sulfonates, phosphates such as tripolyphosphates; and/or one or more plasticizers in form of hydroxy acids; and/or one or more plasticizers selected from the group consisting of monomeric amides, such as acetamides, benzamide, fatty acid amides such as tall oil amides; and/or one or more plasticizers selected from the group consisting of quaternary ammonium compounds such as trimethylglycine, distearyldimethylammoniumchloride; and/or one or more plasticizers selected from the group consisting of vegetable oils such as castor oil, palm oil, linseed oil, soybean oil; and/or tall oil, and/or one or more plasticizers selected from the group consisting of hydrogenated oils, acetylated oils; and/or one or more plasticizers selected from acid methyl esters; and/or one or more plasticizers selected from the group consisting of alkyl polyglucosides, gluconamides, aminoglucoseamides, sucrose esters, sorbitan esters; and/or one or more plasticizers selected from the group consisting of polyethylene glycols, polyethylene glycol ethers; and/or one or more plasticizers in form of polyols, such as glycerol, such as 1,1,1-Tris(hydroxymethyl)propane; and/or triethanolamine.

39. A product according to claim 23, wherein component (iii) is in form of propylene glycols, phenol derivatives, silanols, siloxanes, hydroxy acids, vegetable oils, polyethylene glycols, polyethylene glycol ethers, triethanolamine, or any mixtures thereof.

40. A product according to claim 23, wherein component (iii) comprises one or more plasticizers having a boiling point of 100 to 380 C., more preferred 120 to 300 C., more preferred 140 to 250 C.

41. A product according to claim 23, wherein component (iii) comprises one or more polyethylene glycols having an average molecular weight of 150 to 50000 g/mol, in particular 150 to 4000 g/mol, more particular 150 to 1000 g/mol, preferably 150 to 500 g/mol, more preferably 200 to 400 g/mol.

42. A product according to claim 23, wherein component (iii) is present in the binder composition in an amount of 0.5 to 60, preferably 2.5 to 25, more preferably 3 to 15 wt.-%, based on the dry weight of component (i).

43. A product according to claim 22, the adhesive/binder composition comprising a further component (iv) in form of one or more coupling agents, such as organofunctional silanes.

44. A product according to claim 22, the adhesive/binder composition further comprising a component (v) in form of one or more components selected from the group of bases, such as ammonia, such as alkali metal hydroxides, such as KOH, such as earth alkaline metal hydroxides, such as Ca(OH).sub.2, such as Mg(OH).sub.2, such as amines or any salts thereof.

45. A product according to claim 22, the adhesive/binder composition comprising a further component in form of urea, in particular in an amount 5 to 40 wt.-%, such as 10 to 30 wt.-%, such as 15 to 25 wt.-%, based on the dry weight of component (i).

46. A product according to claim 22, wherein the batt further comprises a further component (vi) in the form of one or more reactive or nonreactive silicones.

47. A product according to claim 22, wherein the batt does not contain an ammonia-oxidized lignin (AOL).

48. A product according to claim 22, with the proviso that the aqueous composition does not comprise a cross-linker selected from carbonyl compounds selected from aldehydes, carbonyl compounds of the formula R[C(O)R.sub.1].sub.x a. in which: b. 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, c. R.sub.1 represents a hydrogen atom or a C.sub.1-C.sub.10 alkyl radical, and d. x varies from 1 to 10.

49. A product according to claim 22, with the proviso that the aqueous composition does not comprise a cross-linker selected from polyamines.

50. A product according to claim 22, with the proviso that the aqueous composition does not comprise a cross-linker selected from: a. epoxy compounds having a molecular weight M.sub.W of 500 or less.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0471] FIG. 1 shows a commonly used model structure of lignosulfonates.

[0472] FIG. 2 is a cross-sectional view of an insulation product according to the invention;

[0473] FIG. 3 is a diagrammatic illustration of a method of the invention prior to the curing oven stage.

[0474] FIG. 2 shows an insulation product 1 formed by an MMVF batt 2. On its underside the batt is provided with a first facing 3. The first facing 3 can have moisture-proof properties. The facing 3 is connected by means of an adhesive layer 4 to the MMVF batt 2. In this particular embodiment, although not essential in the invention, on its top side the MMVF batt 2 is provided with a layer 5 of adhesive. This adhesive layer 5 is used to fix the insulation product onto the objects to be insulated. So as to facilitate storage and transport, a removable second facing 6 provided with a layer of heat-stable silicone material is arranged on adhesive layer 5. It is noted here that the adhesive layer extends a short distance from the edge of the insulation product in order to facilitate detaching of the cover sheet.

[0475] Production of such an insulation product can proceed as follows, as shown in FIG. 3.

[0476] An MMVF batt 2 is made by air-laying a MMVF web with binder and consolidating it (not shown). Starting from this MMVF batt 2 supplied via a conveyor belt formed by rollers 7, a quantity of adhesive is initially supplied by means of an atomizing device 11 provided with nozzles and sprayed in the form of an aqueous composition as defined in the invention onto a first facing 3, provided from a roller, which in this case is flexible and can for instance take the form of a layer of woven or non-woven glass veil, fabric, foil, plastic or a combination thereof. The first facing 3 is arranged on the underside of the MMVF batt 2 by means of a roller 10.

[0477] A second facing layer 6 in the form of heat-stable silicone PE foil is subsequently arranged on the upper side of the MMVF batt 2 by means of a roller 9. As described for the facing layer 3, and again starting from the MMVF batt 2 supplied via conveyor belt of rollers 7, adhesive 4 of the adhesive layer 5 used to fix the insulation product onto the objects to be insulated is applied by means of spray device 8 onto a major surface of batt 2.

[0478] The adhesive for the first facing 3 and the binder for the MMVF matrix are subsequently cured in conventional manner by passing the MMVF batt through a curing oven (not shown).

EXAMPLES

Example 1Peel Strength

[0479] A fleece (Johns Manville Glass fiber nonwoven Evalith DH 50/20) was cut into 3 cm wide strands. An adhesive was applied onto the fleece by a roller at 40 g/m2 loading level. The fleece with the adhesive was pressed onto a finished MMVF product that has 145 kg/m.sup.3 density with 2500 Pa of pressure and cured at 200 to 225 C. for 45 minutes. The binder in the MMVF product was made as follows:

[0480] 730.0 kg of ammonium lignosulfonate was placed in a mixing vessel to which 8.5 l NH4OH (24.7%) was added and stirred. Afterwards, 151 kg Primid XL552 solution (pre-made 31 wt % solution in water) and 43 kg PEG 200 (100% solids) were added and mixed followed by addition of 13 kg Silane (Momentive VS-142 40% activity, 10% in water) and 40 kg silicone (Wacker BS 1052, 12% in water). Curing oven temperature was set to 275 C.

[0481] After curing of the adhesive, the product was left to cool down at room temperature for 2 hours and the adhesion strength was measured. The measurement was done by pulling the end edge of the fleece in a tensile direction perpendicular to the surface of the MMVF product with Mecmesin force gauge and adhesion strength is expressed in grams.

[0482] This method was carried out for four different adhesives to bind the fleece to the MMVF product.

[0483] Adhesive 1, according to the invention, was made as follows:

[0484] To 200.0 g lignosulfonate solution (50% solids), 2.5 g NH4OH (24.7%) was added and mixed followed by addition by addition of 20.0 g Primid XL552 (100% solids), and 23.0 g PEG 200 (100% solids) and mixing. Finally, 120.3 g water was added and mixed to yield 35% solids and then used for testing the adhesion.

[0485] Comparative Adhesive 1 is made as follows (PUF adhesive):

[0486] A phenol-formaldehyde resin is prepared by reacting 37% aq. formaldehyde (606 g) and phenol (189 g) in the presence of 46% aq. potassium hydroxide (25.5 g) at a reaction temperature of 84 C. preceded by a heating rate of approximately 1 C. per minute. The reaction is continued at 84 C. until the acid tolerance of the resin is 4 and most of the phenol is converted. Urea (241 g) is then added and the mixture is cooled.

[0487] The acid tolerance (AT) expresses the number of times a given volume of a adhesive can be diluted with acid without the mixture becoming cloudy (the adhesive precipitates). Sulfuric acid is used to determine the stop criterion in a adhesive production and an acid tolerance lower than 4 indicates the end of the adhesive reaction.

[0488] To measure the AT, a titrant is produced from diluting 2.5 ml conc. sulfuric acid (>99%) with 1 L ion exchanged water. 5 mL of the adhesive to be investigated is then titrated at room temperature with this titrant while keeping the adhesive in motion by manually shaking it; if preferred, use a magnetic stirrer and a magnetic stick. Titration is continued until a slight cloud appears in the adhesive, which does not disappear when the adhesive is shaken.

[0489] The acid tolerance (AT) is calculated by dividing the amount of acid used for the titration (mL) with the amount of sample (mL):

[00002]$\mathrm{AT}=\left(\mathrm{Used}\mathrm{titration}\mathrm{volume}\left(\mathrm{mL}\right)\right)/\left(\mathrm{Sample}\mathrm{volume}\left(\mathrm{mL}\right)\right)$

[0490] Using the urea-modified phenol-formaldehyde resin obtained, an adhesive is made by addition of 25% aq. ammonia (90 mL) and ammonium sulfate (13.2 g) followed by water (1.30 kg).

[0491] The adhesive solids were then measured as described above and the mixture was diluted with the required amount of water and silane (15% adhesive solids solution, 0.5% silane of adhesive solids).

[0492] Comparative adhesive 2 is made as follows (lignin based adhesive):

[0493] 3267 kg of water is charged in 6000 l reactor followed by 287 kg of ammonia water (24.7%). Then 1531 kg of Lignin UPM BioPiva 100 is slowly added over a period of 30 min to 45 min. The mixture is heated to 40 C. and kept at that temperature for 1 hour. After 1 hour a check is made on insolubilized lignin. This can be made by checking the solution on a glass plate or a Hegman gauge. Insolubilized lignin is seen as small particles in the brown adhesive. During the dissolution step will the lignin solution change color from brown to shiny black. After the lignin is completely dissolved, 1 liter of a foam dampening agent (Skumdmper 11-10 from NC-Verodan) is added. Temperature of the batch is maintained at 40 C. Then addition of 307.5 kg 35% hydrogen peroxide is started. The hydrogen peroxide is dosed at a rate of 200-300 l/h. First half of the hydrogen peroxide is added at a rate of 200 l/h where after the dosage rate is increased to 300 l/h.

[0494] During the addition of hydrogen peroxide is the temperature in the reaction mixture controlled by heating or cooling in such a way that a final reaction temperature of 65 C. is reached.

[0495] The final product was analysed for the COOH group content, dry solid matter, pH, viscosity and remaining H.sub.2O.sub.2.Math.60 g of this oxidized lignin (18.2% solids) was mixed with 1.4 g Primid XL552 (100% solids) and 2.8 g PEG200 (100% solids). 0.6 g Silane (Momentive VS-142 40% activity, 10% in water) and 17.4 g water were added and mixed to yield 15% solids.

[0496] Comparative adhesive 3 is made as follows (formaldehyde free, sugar-based adhesive).

[0497] A mixture of 75.1% aq. glucose syrup (19.98 g; thus efficiently 15.0 g glucose syrup), 50% aq. hypophosphorous acid (0.60 g; thus efficiently 0.30 g, 4.55 mmol hypophosphorous acid) and sulfamic acid (0.45 g, 4.63 mmol) in water (30.0 g) was stirred at room temperature until a clear solution was obtained.

[0498] 28% aq. ammonia (0.80 g; thus efficiently 0.22 g, 13.15 mmol ammonia) was then added dropwise until pH=7.9. The adhesive solids was then measured (21.2%).

[0499] The binder mixture was diluted with water (0.403 g/g binder mixture) and 10% aq. silane (0.011 g/g binder mixture, Momentive VS-142). The final binder mixture for mechanical strength studies had pH=7.9.

[0500] The results are shown in Table 1. As can be seen from Table 1, when the adhesive of the invention is used to glue the fleece to the MMVF product, the peel strength is less than PUF but is acceptable and is improved in comparison to comparative formaldehyde free binders.

TABLE-US-00009 TABLE 1 Comparative adhesive 3 Comparative Comparative adhesive (formaldehyde adhesive 2 adhesive 1 adhesive 1 free) (lignin) PUF strength, g 237 132 233 290

Example 2Peel Strength

[0501] Aluminium foil with a thickness of 40 m was cut into 3 cm wide strands. Binder was applied onto the aluminium foil strand by a roller at 30 g/m2 loading level. The aluminium foil with the binder was pressed onto a finished mineral wool product similar to the one in Example 1 with 4000 Pa of pressure and cured at 200-225C for 90 minutes. After curing, the material was left to cool down at room temperature for 2 hours and the adhesion strength was measured. Measurement was done by pulling the end edge of the aluminium foil strand in a tensile direction perpendicular to the surface of the MMVF product with Mecmesin force gauge and adhesion strength is expressed in grams.

[0502] The same adhesives were used as in Example 1. The results are shown in Table 2. As can be seen from Table 2, when the adhesive of the invention is used to glue the aluminium foil to the MMVF product, the peel strength is less than PUF but is acceptable and is improved in comparison to comparative formaldehyde free binders.

TABLE-US-00010 TABLE 1 Comparative adhesive 3 Comparative Comparative adhesive (formaldehyde adhesive 2 adhesive 1 adhesive 1 free) (lignin) PUF strength, g 292 210 282 307