Needling Additive for the Manufacture of Needle Felts of Mineral Wool and Needle Felt Manufactured Therewith

Abstract

A formaldehyde-free and fluorine-free needling additive for the manufacture of needle felts of mineral wool, which contains an aqueous solution or an aqueous dispersion of at least one halogen-free cationic polymer on the basis of azacyclopropane (ethyleneimine). Needle felts of mineral wool that are produced using such needling additive virtually do not emit any aldehydes even in a use of up to 500° C., and are absolutely free of volatile fluorine-containing organic and inorganic compounds, in particular hydrogen fluoride. The needle felts are best suited for heat insulation in household appliances such as ovens, especially those including a high-temperature cleaning program.

Claims

1-10. (canceled)

11. A formaldehyde- and fluorine-free needling additive for the manufacture of needle felts of mineral wool characterized by containing an aqueous solution or an aqueous dispersion of at least one halogen-free cationic polymer on the basis of azacyclopropane (ethyleneimine).

12. The needling additive of claim 11, characterized in that the halogen-free cationic polymer is selected from the group consisting of: a polyethyleneimine, particularly a homopolymer of azacyclopropane, a copolymer of ethan-1,2-diamine and azacyclopropane as well as mixtures thereof.

13. The needling additive of claim 11, characterized in that the halogen-free cationic polymer has a weight average molecular weight (Mw) of between 500 and 3 000 Da, preferably of approximately 800 Da or 1 300 Da.

14. The needling additive of claim 11, characterized in that the aqueous solution has a concentration of 0.05 to 0.5 percent by weight, in particular 0.1 to 0.3 percent by weight, with regard to a fiber mass of halogen-free cationic polymer when being applied onto the fibers of the mineral wool.

15. A needle felt, wherein the needle felt is obtained by needling mineral wool using a formaldehyde- and fluorine-free needling additive characterized by containing an aqueous solution or an aqueous dispersion of at least one halogen-free cationic polymer on the basis of azacyclopropane (ethyleneimine)

16. The needle felt of claim 15, characterized in that, being heated to up to approximately 500° C., substantially neither aldehydes, particularly formaldehyde and/or acetaldehyde, nor halogens or hydrogen halide, in particular HF, are released.

17. A method of using a needling additive for the manufacture of formaldehyde- and fluorine-free needle felts made of mineral wool wherein the needling additive is characterized as containing an aqueous solution or an aqueous dispersion of at least one halogen-free cationic polymer on the basis of azacyclopropane (ethyleneimine).

18. The method of claim 17, characterized in that the halogen-free cationic polymer is selected from the group consisting of: a polyethyleneimine, particularly a homopolymer of azacyclopropane, a copolymer of ethan-1,2-diamine and azacyclopropane as well as mixtures thereof.

19. The method of claim 17, characterized in that the halogen-free cationic polymer has a weight average molecular weight (Mw) of between 500 and 3000 Da, preferably of approximately 800 Da or 1 300 Da.

20. The method of claim 17, characterized in that the aqueous solution has a concentration of 0.05 to 0.5 percent by weight, in particular 0.1 to 0.3 percent by weight, with regard to a fiber mass of halogen-free cationic polymer when being applied onto the fibers of the mineral wool.

Description

EXAMPLE 1

[0055] Polyethyleneimine EAz1300 (CAS 25987-06-8) in water, proportion of solid content of 49.5%, weight average molecular weight 1300 g/mol, water dilutability >1:100 [0056] Solution with 0.2% of solid content: 2.83 kg of EAz1300, 700 kg of water [0057] Solution with 0.1% of solid content: 1.42 kg of EAz1300, 700 kg of water

EXAMPLE 2

[0058] Polyethyleneimine EAz800 (CAS 9002-98-6) proportion of solid content of 93.2%, weight average molecular weight 800 g/mol, water dilutability >1:100 [0059] Solution with 0.2% of solid content: 1.51 kg EAz800, 700 kg of water [0060] Solution with 0.1% of solid content: 0.75 kg EAz800, 700 kg of water

[0061] Determination of formaldehyde by way of a reaction with 2,4-Dinitrophenylhydrazine [0062] 2,4-Dinitrophenylhydrazine (Aldrich, CAS 119-26-6) [0063] Sulphuric acid (VWR, CAS 7664-93-9) [0064] Acetonitrile (Roth for HPLC-MS, CAS 75-05-8) [0065] Ammonium acetate (VWR high purity for analysis, CAS 631-61-8) [0066] Basic standard formaldehyde: (Hach & Lange, CAS 50-00-0) 4000 ppm [0067] DNPH reaction solution: 400 mg 2,4-Dinitrophenylhydrazine (DNPH) with 4 ml of H2SO4 (0.5 M) solved in 1000 ml of acetonitrile (ACN) [0068] Water (VWR, high purity for HPLC-MS)

[0069] Emission analytics GC-MS [0070] Methanol (VWR, SupraSolv for GC-MS) [0071] Tributylamine (Aldrich CAS: 102-82-9, “reagent plus”) C12H27N 185.35 g/mol [0072] Basic standard: 7.6 mg of tributylamine in 15.6837 g of methanol=480 ppm [0073] Decanol (Aldrich, LOCAS: 112-30-1, Kp: 230° C.) [0074] Perfluorooctane (Aldrich, CAS: 307-34-4, Kp: 103-104° C.), C8F18, MG: 438.06 g/mol [0075] Basic standard: 23.1 mg of perfluorooctane in 12.6029 g decanol=1833 ppm [0076] Glass filter (VWR) held for 72 h at 350° C. as carrier material for calibration by way of thermodesorption [0077] Desorption tube, unfilled, with frit base, purified by heating at 280° C. in a nitrogen stream

[0078] Production of needle felt: [0079] Gross density: 50 kg/m3 [0080] Target thickness: 20 mm [0081] Flow-rates: Glass: 591 kg/h [0082] For 0.2% Target proportion EAz1300/EAz800 (0.2%): 419 l/h [0083] Für 0.1% Target proportion EAz1300/EAz800 (0,1%): 416 l/h [0084] Belt speed: 433 strokes/min [0085] Belt speed (receiving belt): 4.3 m/min

[0086] Determination of the emission of formaldehyde by baking out in air at 350° C. and 500° C. in accordance with the provisions of Stiftung Warentest (German consumer organization)

[0087] 10 g each of the corresponding material are positioned in a quartz glass tube and the tube is heated in a tubular furnace to 350° or 500° C. In so doing, dry, synthetic air flows through the sample for 60 min with 1 l/min and the waste gas is led through washing bottles filled with water.

[0088] The emission samples thus obtained are transferred to a 250 ml volumetric flask and filled with water up to a mark. Subsequently, 10 ml of the solution are transferred to a 25 ml flask and filled up with a DNPH reaction solution up to the mark. After 1 hour the sample is analyzed and evaluated.

[0089] HPLC column: [0090] LiChroCART 150-4.6 Purospher Star RP-18e [0091] Oven temperature: 35° C. [0092] Injection volume: 50 μl [0093] Solvent and description of gradient: [0094] A: Water/5% ACN/0.1% CH.sub.3COONH.sub.4; B: MeOH, [0095] Flow: 0.8 ml/min [0096] A: 99%, 0 min; 96%, 5 min; 40%, 10 min; 40%, 20 min; 4%, 22 min; 4%, 25 min; 99%, 26 min; 99%, 30 min [0097] Detection parameter: [0098] UV: 355 nm, 25 min [0099] RT [min]: 19.17 min (Formaldehyde-DNPH); 22.55 min (Acetaldehyde-DNPH) [0100] Determination of concentration: peak area according to calibration function

[0101] Determination of volatile organic substances by way of thermodesorption GC-MS [0102] Calibration tributylamine in methanol: In tared desorption tubes with glass filter as carrier material 1-4*10.sup.−6 g of a standard substance are placed, which corresponds to approximately 10-45 mg of a basic standard in methanol, [0103] Conditions Thermodesorber Calibration [0104] Conditioning: 1 min per mg of standard at 35° C., 20 ml/min of helium [0105] Measuring: 10 min at 250° C., 20 ml/min of helium [0106] Calibration perfluoroctane in decanol: 327.2 mg of basic standard with 813.6 mg of decanol diluted to a content of 526 ppm, in tared desorption tube with glass filter as carrier material 1-4*10.sup.−6 g of a standard substance are placed, which corresponds to approximately 10-45 mg of a basic standard in decanol, [0107] Measuring: 10 min at 150° C., 20 ml/min of helium

[0108] Test arrangement GC-MS: [0109] GCMS-QP2010 Plus Shimadzu [0110] Column: Rxi-624Sil MS 30 m Restek [0111] Detector: MSD 40-800 AMU [0112] Temperature ion source: 200.00° C. [0113] Temperature interface :150.00° C. [0114] Solvent cut time: 0.80 min [0115] Start time: 0.90 min [0116] End time: 61.90 min [0117] ACQ mode: Scan [0118] Event time: 0.20 sec [0119] Scan speed: 5000 [0120] Start m/z : 41.00 [0121] End m/z: 800.00 [0122] In case of decanol end time 37.5 min [0123] Injection temperature: 26.50° C. [0124] Injection mode: without split [0125] Sampling time: 1.00 min [0126] Input pressure: 91.1 kPa [0127] Total flow: 29.3 ml/min [0128] Column flow: 4.39 ml/min [0129] Temperature program:

TABLE-US-00001 Rate [°/min] Temperature [° C.] Hold time (min) — 35 15 2 60 5 5 130 3 10 190 2 10 225 1 [0130] Tributylamine: 46.7-47.6 min, maximum 46.9 min [0131] Perfluorooctane: 1.1-1.9 min, maximum 1.2 min [0132] Integration of standard needle felt:1.0 min-51.8 min [0133] Integration of needle felt with EAz1300/EAz800: 2.4 min-51.8 min

[0134] For determining the emissions of fluorine compounds and VOC 100-200 mg or the respective material sample were used. In table 2, results of a one-time run of the temperature program and a repeated run, five-time herein, of the temperature program are contrasted with each other, the emission for the five runs being added up. It turned out that with the fifth run the emission decreased to the range of the detection limit, so that repeated heating was terminated.

TABLE-US-00002 TABLE 1 Emissions of formaldehyde according to the methods and provisions of Stiftung Warentest (German consumer organization) Formaldehyde Acetaldehyde Sample Concentration Temperature [ppm] [ppm] EAz.sub.800 0.1% 350° C. 2.6 1.2 EAz.sub.800 0.1% 500° C. 3.3 1.5 EAz.sub.800 0.2% 350° C. 4.9 2.4 EAz.sub.800 0.2% 500° C. 6.5 2.9 EAz.sub.1300 0.1% 350° C. 4.8 2.0 EAz.sub.1300 0.1% 500° C. 4.3 3.4 EAz.sub.1300 0.2% 350° C. 7.8 4.1 EAz.sub.1300 0.2% 500° C. 8.7 6.8 Fomblin 0.1% 350° C. 1.7 not detected FE 20C Fomblin 0.1% 500° C. 3.5 not detected FE 20C Fomblin 0.2% 350° C. 4.0 not detected FE 20C Fomblin 0.2% 500° C. 8.2 n.e. FE 20C

TABLE-US-00003 TABLE 2 Emitted fluorine compounds/total emission of volatile organic compounds during single and multiple heating up Single heating up Multiple heating up Sum Needling Fluorine compounds/ Fluorine compounds/ additive VOC [ppm] VOC [ppm] Fomblin FE20C 69.8/—* 186.7/—* EAz1300 n.n./4.3 n.n./11.7 EAz800 n.n./7.8 n.n./13.4 *VOC signal is fully superimposed by the fluorine signal. n.n. not traceable

[0135] The determined fluorine compounds are indicated as perfluorooctane.

[0136] Thus, the needle felts of the present invention are excellently suited for use as heat insulating material in modern household appliances such as ovens or stoves with pyrolytic cleaning at increased temperature.

Comparative Example in Accordance with DE 196 28 477 C1

[0137] For the preparation of the formulation of needling additive an aqueous micro-emulsion of a perfluoroether is used, which is commercially available under the name “Fomblin FE 20C”. The emulsion has a polymer proportion of approximately 20 percent by weight and is stabilized with approximately 18 percent by weight of t-butyl alcohol.

[0138] For preparation of a solution or dispersion ready to use the commercially available solution is diluted with water to a polymer proportion of approximately 12 percent by weight.

[0139] By further adding water an end concentration of approximately 0.1 and 0.2 percent by weight of perfluoropolyether is set and then sprayed onto a glass wool felt, which is then guided under a needle bank and subjected to needling, using the parameters in accordance with examples 1 and 2.

[0140] A needle felt of glass wool produced in such a manner has a gross density of approximately 50 kg/m.sup.3 and a thickness of approximately 20 mm.

[0141] By analogy of the examples 1 and 2, the needle felts thus produced were examined for the emission of formaldehyde and volatile fluorine compounds.

[0142] A formaldehyde content of 2 to 8 ppm was measured (cf. table 1). The value is below the stipulated threshold values, so that a formaldehyde-free product likewise may be assumed.

[0143] However, in measuring the needle felts of the comparative example of volatile fluorine compounds by way of GC-MS values of up to approximately 190 ppm were found (cf. table 2). It thus is to be assumed that the needle felts of the prior art, which were produced using the perfluorinated needling additive, release fluorine compounds to the environment of an oven.