AU2008234986A1

AU2008234986A1 - Insulating product in particular thermal containing a binder based on phenol-formaldehyde resin and method for making same

Info

Publication number: AU2008234986A1
Application number: AU2008234986A
Authority: AU
Inventors: Philippe Espiard; Bruno Mahieuxe
Original assignee: Saint Gobain Isover SA France
Current assignee: Saint Gobain Isover SA France
Priority date: 2000-06-13
Filing date: 2008-10-21
Publication date: 2008-11-27
Anticipated expiration: 2021-06-13
Also published as: AU2008234986B2; AU2006202926A1

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant(s): SAINT-GOBAIN ISOVER Invention Title: INSULATING PRODUCT IN PARTICULAR THERMAL CONTAINING A BINDER BASED ON PHENOL-FORMALDEHYDE RESIN AND METHOD FOR MAKING SAME The following statement is a full description of this invention, including the best method for performing it known to me/us: P47913AU 2 PaLSLFrng Appftaton 2008-10-20.doc (M) -1A- 00 INSULATION PRODUCT, ESPECIALLY HEAT INSULATION

PRODUCT,

AND MANUFACTURE

THEREOF

0 The invention relates to the field of insulation products, especially heat or sound insulation products, based on mineral wool and on an organic binder based on \O a phenol-formaldehyde resin. The invention relates more 00 particularly to the reduction of various pollutant CC emissions during the manufacture of such products based ci 10 on mineral wool [lacuna] comprises a first step of 00 manufacture of the wool itself by forming and drawing, and a shaping step in which the mineral wool is collected on a receiving member in the form of a lap.

To ensure cohesion of the lap, the wool is sprayed, during its passage toward the receiving member, with a sizing composition that contains a thermosetting resin.

The lap thus treated is then subjected to a heat treatment in an oven to crosslink the resin and obtain a product having the desired properties, such as dimensional stability, mechanical strength, recovery of thickness after compression and uniform color.

The sizing compositions are generally in the form of an aqueous composition containing a phenol-formaldehyde resin and additives such as resin-curing catalyst, adhesion-promoting silane, dust-preventing mineral oils, etc.

In order for the composition to be able to be distributed more generally by spraying, the resin should be sufficiently dilutable in water. To this end, it is common practice to perform the condensation reaction between formaldehyde and phenol by limiting the degree of condensation of the monomers, in order to avoid the formation of long, relatively nonhydrophilic chains which reduce the dilutability. Consequently, the resin contains a certain proportion of unreacted monomers, in particular formaldehyde, whose volatility 2 00 O may lead to undesirable emissions of organic compounds CI into the plant atmosphere.

0 For this reason, the phenol-formaldehyde condensation C- 5 product is generally reacted with urea, which traps the free formaldehyde forming nonvolatile condensation IND products. The presence of urea in the resin also affords oo 0 a major economic advantage associated with its low cost, since it may introduced in relatively large amount with 0 10 substantially affecting the qualities of the resin 0o Sespecially with respect to the mechanical properties of C-I the final product, while appreciably lowering the total cost of the resin.

Nevertheless, it has been observed that this solution is not entirely satisfactory as regards atmospheric pollution, since the urea-formaldehyde condensation products have been found to be relatively heat-unstable, such that, during the use of the resin for sizing mineral wool, in the course of which the resin is subjected to temperatures above 100 0 C, the urea-formaldehyde condensation product regenerates urea, formaldehyde and ammonia by the effect of heat, which are released into the plant atmosphere.

Advantageously, the present invention may render the manufacture of insulating products less polluting, more particularly as regards the emissions of ammonia on the manufacturing line, without penalizing the production cost of the insulating product.

The invention is based on the observation that it is possible to significantly reduce the emissions of ammonia in the manufacture of an insulating product while at the same time using a size that retains a certain proportion of urea and that is thus of competitive cost.

H;\Simeona\Keep\Speci\200126763 .dc 14/10/05 3 00 O In this regard, one subject of the invention is an CI insulating product based on mineral wool sized with a o binder based on a phenol-formaldehyde resin, characterized in that the binder comprises, as a mixture: to 90 parts by weight of a phenol-formaldehyde ND resol having a content of free formaldehyde of less 00 than or equal to 25% (by weight relative to the dry Sweight of resin) and a content of free phenol of less 00 10 than or equal to 2.5% by weight relative to the dry weight of resin obtained, by condensation in basic (N medium of phenol and formaldehyde in an F/P molar ratio from about 2.5 to 4, until the condensation product neutralized with sulfuric acid has a dilutability in water of greater than 500% and less than or equal to 1 500%; to 40 parts by weight of urea.

The free phenol content is first limited by forcing the condensation reaction to a degree that is sufficient for almost complete consumption of this minority starting material. With an F/P ratio of greater than 1, but not too high, preferably less than or equal to 3.2, the condensation takes place forming species of moderately high molecular weight, with, consequently, a higher consumption of formaldehyde than that which would give very long chains of phenol-formaldehyde condensates.

Next, once the condensation reaction of the resol is complete, the remaining formaldehyde molecules present in free form are captured by means of urea, the amount of which may be proportionately smaller the lower the free formaldehyde content of the resol.

H: \Simeouia\Keep\Speci\20012676 3 7 -dC 14/10/oS 4 00 The proportion of urea in the binder mixture may thus be c limited, while conserving low contents of free volatile O organic compounds in the binder. Limitation of the emissions of volatile organic compounds such as phenol and C 5 formaldehyde is thus achieved, while at the same time reducing the amount of ammonia released onto the DO manufacturing line.

00 Mn To monitor the reaction progress for formation of the OO 10 resol under the conditions required for the invention, Sthree characteristic magnitudes are measured: the content of free phenol and of free formaldehyde, which characterize the reaction progress, the dilutability of the neutralized resol, which characterizes the length of the condensates formed.

The free phenol content in the resol before addition of urea is less than or equal to 2.5% by weight of phenol relative to the dry weight of resin, for a resol solids content of about 35% to 45%. Preferably, the free phenol content is less than or equal to 2% relative to the dry weight of resin, and advantageously 1.7% relative to the dry weight of resin. It may especially be from about to for example from 0.7% to 1.6% relative to the dry weight of resin.

The free formaldehyde content in the resol is less than or equal to 25% by dry weight of resin for a resol solids content of between 35 and 45 [lacuna]. Preferably, the free formaldehyde content is less than or equal to relative to the dry weight of the resin, advantageously 15.5% and in particular 12%. It may especially be from about 2% to 4%.

H:\imeona\Keep\peci\2001267637.doC 14/10/05 5 00 The dilutability of the resol corresponds to the maximum c dilution factor of the resol for which the formation of O permanent cloudness of the dilution is not observed. The 0 dilutability is expressed by the volume of water, as a percentage of the volume of resol, that may be added to the resol before bringing about the formation of permanent D cloudiness. Thus, a dilutability of 1 500% means that O0 ml of resin may be diluted with 15 x 10 ml of water Swithout the mixture becoming cloudy. In general and CO 10 according to the invention, this measurement is performed 00 Susing for the dilution temperate deionized water, i.e.

Cy water at room temperature, of about 15 to 25 0 C, generally about 20 0 C (in this temperature range, the dilutability does not vary significantly).

The progress of the condensation is monitored by measuring the dilutability of the resol neutralized with sulfuric acid. Specifically, it is generally found that the resol synthesized in basic medium has a high dilutability at basic pH (in general at pH 9) with relatively small variation, even when it contains species of very high molecular weight. In contrast, when the resol is neutralized with sulfuric acid, the dilutability varies markedly less as the molecular weight of the phenolformaldehyde condensates increases. The appearance of compounds of undesirable molecular weight may thus be monitored.

The resols used are thus characterized by a dilutability of greater than 500% and less than or equal to 1 500% in the form neutralized with sulfuric acid; preferably, the dilutability is from more than 500% to 1 000% in the neutralized form. The term "neutralization" means the addition of an amount of H 2

SO

4 that is sufficient to react with all the hydroxyl OH- introduced via the basic catalyst.

H: \Simona\Keep\Speci\2001267637.doc 14/10/05 11 00 filaments before they are received on a conveyor belt 3 containing a receiving chamber equipped with suction c_ means for forcing the glass wool onto the belt. The O conveyor belt passes into a shaping zone in which the glass wool may be compressed vertically and optionally longitudinally, and the shaped mass is then conveyed into an oven for crosslinking the binder, in which a

\O

00 temperature of about 280°C prevails.

The binder content of the product is measured by the 00 loss on ignition of said product, which in this case is of the total weight of product.

The gaseous emissions are collected at all the points in the manufacturing line, especially in the forming zone, and at the oven inlet and outlet, and the phenol, formaldehyde and ammonia contained in these collected emissions are assayed. The cumulative emissions for the entire line are given in table 1 below.

Test 1 shows that by adding ammonium sulfite, the level of ammonia emissions does admittedly increase slightly as a consequence of the presence of the ammonium ions, but the level of free formaldehyde is remarkably low.

One advantageous variant consists in omitting the aqueous ammonia while retaining the ammonium sulfite, optionally in reduced amount.

Test 2, which uses a resin urea premix and does not employ aqueous ammonia, gives very good emissions results as regards both formaldehyde and ammonia.

The addition of aqueous ammonia to the premix of test 3 makes it possible to reduce the level of emitted formaldehyde, with a level of emitted ammonia that remains tolerable.

12 00 Finally, the addition of ammonium sulfite in test 4 makes it possible to reduce the level of emitted Sformaldehyde, with a level of emitted formaldehyde that O also remains tolerable.

00 00 2008234986 21 Oct 2008 13 Example (test) 1(1) 1 (2) 1(3) 1(4) 2(1) 2(2) TABLE 1 Formulation (resin/urea)*/ammonium sulfate/20% aqueous ammonia/ammonium sulfite (resin/urea) in parentheses in the case of a premix 80/20/2.5/5/5 (75/25)/1/0/0 (75/25/2 20% aqueous ammonia)/2/0/0 (75/25/2 20% aqueous ammonia)/2/0/2 (70/30/2 20% aqueous ammonia)/2/3/0 (70/30/2 20% aqueous ammonia)/2/0/0 Emissions (g/kg of glass) Free phenol Formaldehyde 0.7 0.2 0.6 0.4 0.6 0.3 0.6 0.3 0.4 0.6 0.3 0.6 Ammoniai 1.2 1.2 1.2 0.9 1.4 1.3 14 00 0EXAMPLE 2 A phenol-formaldehyde resin is prepared by introducing O into a reactor with stirring, which will be maintained throughout the manufacturing cycle, 100 kg of phenol and 276 kg of formaldehyde as an aqueous 37% solution, and the temperature in the reactor is brought to 450C.

00 The formaldehyde/phenol molar ratio is 3.2.

12.7 kg of sodium hydroxide as an aqueous 47% solution, oo i.e. a sodium hydroxide/phenol weight ratio of i.e.

a molar ratio of 14.1%, are introduced uniformly over a period of 30 minutes, while maintaining the temperature at 45 0

C.

Immediately after the end of this addition, the temperature is raised to 700°C over 30 minutes, and this temperature is maintained for a period of about 130 minutes. At the end of this period, the dilutability of the resol neutralized with sulfuric acid is 1 200%.

The reactor and the reaction mixture are then cooled from 70°C to 35°C over 35 minutes.

The pH of the reaction medium is then adjusted to 7.3 with sulfamic acid as an aqueous 15% solution (about 88 kg). The operation takes about 90 minutes, while cooling the reaction mixture to 200C.

The neutralized resol has a free formaldehyde content of 2.5% and a free phenol content of 0.5% by weight of the resol, for a solids content of 36%.

The dilutability of the resol neutralized with sulfamic acid is 1 800% and falls to 1 300% after three weeks of storage at 120°C with gentle stirring.

15 00 This resin is used to formulate two size compositions C based on a premix of resol and urea, the formulations of

C)

O which are given in table i.

C- 5 These sizes are used as in example 1 for the manufacture of an insulating product based on glass wool, and the IND results of gas emissions measurements are given in table 00 1.

00 10 Test 1 shows that, despite the presence of aqueous ammonia in the size, the level of emitted ammonia remains C- tolerable, and may be very simply reduced if the aqueous ammonia is omitted, as shown by the partial omission of aqueous ammonia in test 2.

The level of emissions of formaldehyde and phenol in these two tests are, moreover, very satisfactory.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. Thus, for claims defining the presence of an integer within a range or at a given amount or level, the term comprising should not be interpreted as suggesting that there may be a greater amount or level of that integer.

H:\Simcona\Keep\Speci\2001267637.doc 14/10/05

Claims

1. An insulating product based on mineral wool sized with a binder based on a phenol-formaldehyde resin, C-i 5 characterized in that the binder comprises, as a mixture without heating: -1 60 to 90 parts by weight of a phenol-formaldehyde 00 resol having a content of free formaldehyde of less cthan or equal to 25% by weight relative to the dry 00 10 weight of resin and a content of free phenol of less 8 than or equal to 2.5% by weight relative to the dry c-i weight of resin obtained, by condensation in basic medium of phenol and formaldehyde in an F/P molar ratio from about 2.5 to 4, until the condensation product neutralized with sulfuric acid has a dilutability in water of greater than 500% and less than or equal to 1 500%; 10 to 40 parts by weight of urea.

2. The insulating product as claimed in claim 1, characterized in that the free phenol content of the resol before adding urea is less than or equal to 2% relative to the dry weight of resin.

3. The insulating product as claimed in claim 2, characterized in that said phenol content is from about to 1.7% relative to the dry weight of resin.

4. The insulating product as claimed in any one of claims 1 to 3, characterized in that the free formaldehyde content before adding urea is less than or equal to relative to the dry weight of resin.

5. The insulating product as claimed in any one of the preceding claims, characterized in that the ratio F/P is from about 2.5 to 3.2. H:\marieag\Keep\Speci\200126,63,.doc 24/02/06 17 00 O

6. The insulating product as claimed in any one of the c preceding claims, characterized in that the resol is o obtained by reacting phenol and formaldehyde, in the presence of a basic catalyst, at a temperature from about C- 5 50 to 80 0 C, for a period from about 80 to 200 minutes.

7. The insulating product as claimed in claim 6, 00 characterized in that said temperature is from about 60 to 0 C. 00

8. The insulating product as claimed in claim 6, C-I characterized in that said temperature is from about 70 0 C.

9. The insulating product of any one of claims 6 to 8, characterized in that said period is from about 90 to 150 minutes.

The insulating product as claimed in any one of claims 6 to 9, characterized in that said basic catalyst is sodium hydroxide.

11. The insulating product as claimed in any one of the preceding claims, characterized in that the resol is neutralized with at least one acid chosen from boric acid or an equivalent borate, sulfamic acid or an equivalent sulfamate, and an amino acid.

12. The insulating product as claimed in any one of the preceding claims, characterized in that the mixture comprises 60 to 90 parts by dry weight of resol per 40 to parts by weight of urea.

13. The insulating product as claimed in any one of the preceding claims, characterized in that the mixture comprises at least 65 parts by dry weight of resol per not more than 35 parts by weight of urea. H \Simeona\Keep\Spei2001267637.doc 14/10/05 18 00

14. The insulating product as claimed in any one of the C- preceding claims, characterized in that the mixture O comprises from 70 to 85 parts by dry weight of resol per 0 15 to 30 parts by weight of urea. CM The insulating product as claimed in any one of the IND preceding claims, characterized in that the binder also, 00 00 comprises from 1 to 10 parts by weight of ammonium sulfite Sper 100 parts by dry weight of resol and urea.

CM 00

16. A size composition for an insulating product, characterized in that it comprises, as a mixture without heating: 60 to 90 parts by weight of a phenol-formaldehyde resol having a content of free formaldehyde of less than or equal to 25% by weight relative to the dry weight of resin and a content of free phenol of less than or equal to 2.5% by weight relative to the dry weight of resin obtained, by condensation in basic medium of phenol and formaldehyde in an F/P molar ratio from about 2.5 to 4, until the condensation product neutralized with sulfuric acid has a dilutability in water of greater than 500% and less than or equal to 1 500%; to 40 parts by weight of urea.

17. The size composition as claimed in claim 16, characterized in that the mixture comprises 60 to 90 parts by dry weight of resol per 40 to 10 parts by weight of urea.

18. The size composition as claimed in claim 16 or 17, characterized in that the mixture comprises from 70 to parts by dry weight of resol 15 to 30 parts by weight of urea. H \marieag\Keep\Speci\20o12676 3 .doc 24/02/06 19 00 0

19. The size composition as claimed in any one of claims C-I 16 to 18, characterized in that it also comprises from 1 O to 20 parts by weight of ammonium sulfite per 100 parts by O dry weight of resol and urea. The use of a size composition as claimed in any one \D of claims 16 to 19 to reduce the ammonia emissions during 00 0 the manufacture of an insulating product.

C' 10

21. A process for manufacturing an insulating product 00 Sbased on mineral wool sized with a formaldehyde-phenol C- binder, characterized in that a size composition as claimed in any one of claims 16 to 19 is sprayed onto the mineral wool, and in that the cumulative ammonia emissions is for all the manufacturing steps are less than 10 grams of ammonia per kilogram of mineral wool.

22. An insulating product, a process for manufacturing an insulating product, or size composition for an insulating product or uses thereof in the manufacture of an insulating product, substantially as herein described with reference to the examples herein. N\Melbourn\Cese\Paen\47OOO-47999\P479 13AU I\SpeciS\P479 3AU I Specification 2008.3-14 doc