FR3032197A1 - SIZING COMPOSITION FOR MINERAL WOOL BASED ON ALKALI OR ALKALINE-TERROUS METAL SALT OF LIGNOSULFONIC ACID AND A CARBONYL COMPOUND, AND INSULATING PRODUCTS OBTAINED - Google Patents

Abstract

The present invention relates to a sizing composition for insulating products based on mineral wool, in particular glass or rock, which comprises - at least one alkaline or alkaline earth metal salt of lignosulfonic acid, and - at at least one carbonyl compound of formula R- [C (O) R 1] x (I) in which: R represents a saturated or unsaturated, linear, branched or cyclic hydrocarbon-based radical, a radical containing one or more aromatic rings consisting of or 6 carbon atoms, a radical containing one or more aromatic heterocycles containing 4 or 5 carbon atoms and an oxygen, nitrogen or sulfur atom, the radical R possibly containing other functional groups, in particular hydroxyl or alkoxy groups , in particular methoxy, - R1 represents a hydrogen atom or a C1-C10 alkyl radical, and - x varies from 1 to 10. It also relates to the mineral fiber-based insulating products obtained and their process of manufacture. we.

Description

CIPO - Patent acoustic, based on mineral wool, especially glass or rock, and an organic binder free of formaldehyde. More particularly, the invention relates to a sizing composition capable of crosslinking to form said organic binder which contains at least one alkali metal or alkaline earth metal salt of lignosulfonic acid and at least one carbonyl compound, as well as the products of insulation that result. The manufacture of insulating products based on mineral wool generally comprises a step of manufacturing the wool itself, which can be carried out by various methods, for example according to the known technique of internal or external centrifugal fiber drawing. In particular, the internal centrifugation consists in introducing the molten mineral material (glass or rock) into a centrifugal device comprising a multitude of small orifices, the material being projected towards the peripheral wall of the device under the action of the centrifugal force and escaping in the form of filaments. At the outlet of the centrifugal device, the filaments are drawn and driven to a receiving member by a gaseous stream of high temperature and velocity to form a web of fibers (or mineral wool). To ensure the assembly of the fibers together and to allow the web to have cohesion, a sizing composition is sprayed onto the fibers in the path from the outlet of the centrifugal device to the receiving member. a thermosetting resin. The layer of fibers coated with the sizing is subjected to a heat treatment, at a temperature generally greater than 100 ° C., in order to effect the polycondensation of the resin and thus to obtain a thermal and / or acoustic insulation product having specific properties, including dimensional stability, tensile strength, thickness recovery after compression and a homogeneous color. The sizing composition to be sprayed on the mineral wool is generally in the form of an aqueous solution containing the thermosetting resin and additives such as a resin crosslinking catalyst, an adhesion promoter silane and a mineral oil. Dust control, The sizing composition is most often applied to the fibers by spraying.

The properties of the sizing composition depend to a large extent on the characteristics of the resin. From the point of view of application, it is necessary that the sizing composition has good sprayability and can be deposited on the surface of the fibers in order to bind them effectively.

The resin should be stable for a given period of time before being used to form the sizing composition, which composition is generally prepared at the time of use by mixing the above-mentioned resin and additives. At the regulatory level, it is necessary for the resin to be considered as non-polluting, that is to say that it contains - and that it generates during the sizing step or later - as little as possible of compounds that may be harmful to human health or the environment. The thermosetting resins most commonly used are phenolic resins belonging to the family of resoles. In addition to their good cross-linking ability under the aforementioned thermal conditions, these resins are water-soluble, have good affinity for mineral fibers, especially glass fibers, and are relatively inexpensive. Resols are generally obtained by reacting a phenol and an aldehyde under basic conditions, a proportion of which of which unreacted compounds are found in the final resin. The most used aldehyde is formaldehyde, the presence of which in the form of free formaldehyde is not desired because of its proven harmful effects. As environmental protection regulations become more stringent, insulation manufacturers have to look for ways to further reduce unwanted emissions, particularly of formaldehyde, at the manufacturing level. insulation products or their use. Solutions for replacing the resols in the sizing compositions are known and are based on the use of a carboxylic acid polymer and a hydroxyl compound. In US 5,340,868, the sizing comprises a polycarboxylic polymer, a p-hydroxylamide and an at least trifunctional monomeric carboxylic acid.

Sizing compositions are also known which comprise a polycarboxylic polymer, a polyol and a catalyst, which catalyst is a phosphorus-containing catalyst (US 5,318,990, US 5,661,213, US 6331,350, US 2003/0008978), fluoroborate (US 5,977,232) or cyanamide, dicyanamide or cyanoguanidine (US 5,932,689).

Sizing compositions comprising an alkanolamine containing at least two hydroxyl groups and a polycarboxylic polymer (US 6,071,994, US 6,099,773, US 6,146,746, US 2002/0091185) associated with a copolymer (US 6) are also known. 299,936). It has also been proposed to replace all or part of the hydroxyl compound with a saccharide. In US 2005/0215153, there is described a sizing formed from a pre-binder containing a carboxylic acid polymer and a polyol, and a dextrin as a co-binder. On the other hand, there are known saccharide adhesive compositions which can be used as adhesives for mineral wool. In US 5,895,804, the composition comprises a polycarboxylic polymer having at least two carboxylic acid functional groups and a molecular weight of at least 1000, and a polysaccharide having a molecular weight of at least 10000. In VVO 2009/080938, the The sizing composition comprises a monosaccharide and / or a polysaccharide and a polycarboxylic organic acid of molar mass less than 1000, optionally in combination with a catalyst for adjusting the crosslinking start temperature. Also known is a formaldehyde-free aqueous sizing composition which comprises a Maillard reaction product, in particular combining a reducing sugar, a carboxylic acid and ammonia (NO 2007/014236). In VVO 2009/019232 and VVO 2009/019235, it is proposed to substitute the carboxylic acid with an acid precursor derived from an inorganic salt, especially an ammonium salt which has the additional advantage of being able to replace all or part of the ammonia. Finally, VVO 2012/172262 discloses a sizing composition for mineral wool which comprises a lignosulfonic acid salt, an oligosaccharide and a crosslinking catalyst. The present invention aims to provide an alternative to sizing compositions for insulating products based on mineral wool, which contains no formaldehyde and nitrogen compounds, and which has improved physico-chemical properties compared to those described. in 15 \ NO 2012/172262. This object is achieved according to the invention by the sizing composition for insulating products based on mineral wool, in particular glass or rock, which comprises - at least one alkaline or alkaline-earth metal salt of lignosulfonic acid and at least one carbonyl compound of formula R - [C (O) R 1] x (I) in which: - R represents a hydrocarbon radical, linear, branched or cyclic, saturated or unsaturated, a radical containing one or more aromatic rings consisting of 5 or 6 carbon atoms, a radical containing one or more aromatic heterocycles containing 4 or 5 carbon atoms and an oxygen, nitrogen or sulfur atom, the radical R possibly containing other groups functional groups, especially hydroxyl or alkoxy, in particular metho> C y, - R 1 represents a hydrogen atom or a C 1 -C 10 alkyl radical, and x varies from 1 to 10. The alkali metal or alkaline earth metal salts of lignosulfonic acid are usually mixtures complexes of several lignosulphonic acids in salified form, commonly referred to as "lignosulphonates". Lignosulphonates are by-products from the treatment of wood for the manufacture of paper pulp using the "sulphite" process. This process, which uses a sulfite or a bisulfite, allows depending on the nature of the counterion employed to obtain in particular alkali or alkaline earth metal salts of lignosulfonic acid. In the present invention, the preferred lignosulfonic acid alkali metal salts are sodium or potassium lignosulfonates, preferably sodium, and the preferred lignosulfonic acid alkaline earth metal salts are magnesium or calcium lignosulfonates. . The preferred carbonyl compound is an aldehyde of the formula (1) in which the radical R 1 represents a hydrogen atom and x is at most equal to 6. The carbonyl function of the aldehyde can in this case be form of an acetal or a hemiacetal of formula (11) below: OR2 1 R-C-OR3H (II) in which R2 represents a C1-C10 alkyl radical, and R3 represents a hydrogen atom or a C1-C10 alkyl radical. Even more preferably, the carbonyl compound of formula (I) is a monofunctional or polyfunctional aldehyde selected from the group consisting of acetaldehyde, propionaldehyde, dimethoxyethanal, butyraldehyde, especially n-butyraldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, 2-hydroxyglutaraldehyde, 3-methylglutaraldehyde, adipaldehyde, sualaldehyde, sebacaldehyde, malaldehyde, fumaraldehyde, poly (acroleins), starch dialdehyde, furfural (2-furancarboxyaldehyde) ), 5-methylfurfural (2-methyl-furancarboxyaldehyde), hydroxymethylfurfural (2-hydroxymethyl-5-furancarboxyalkyl), 2,5-furancarboxydialdehyde, vaniline and vanilin polymers, especially bis-vanillin. , cinnamaldehyde and cinnamaldehyde polymers, phthalaldehyde, isophthalaldehyde, terephthalaldehyde and the oligomers of formulas (III) and (IV) below: wherein: A represents a divalent radical -CH2-, -CH (OH) - or -CH2-O-CH2-, n varies from 1 to 8, (IV) in which n 'varies from 1 to 9. Hydroxymethylfurfural is particularly preferred.

In the sizing composition, the alkali metal or alkaline earth metal salt of lignosulfonic acid is generally 10 to 95% by weight of the mixture consisting of the lignosulfonic acid alkali or alkaline earth metal salt and the carbonyl compound. of the formula (I), preferably 20 to 80%, advantageously 30 to 70% and more preferably 40 to 60%. The sizing composition according to the invention may further comprise the conventional additives hereafter in the following proportions. calculated on the basis of 100 parts by weight of alkali metal or alkaline earth metal salt of lignosulfonic acid and of carbonyl compound of formula (I): 0 to 5 parts of silane, in particular an aminosilane, 20 - 0 to 20 parts oil, preferably 4 to 15 parts, 0 to 30 parts of glycerol, preferably 0 to 20 parts, 0 to 5 parts of a silicone, 0 to 40 parts of an organic phosphate, preferably 0 to to 30 parts, - 20 parts of an extender, in particular s carbohydrates such as molasses or dextrin, and animal or vegetable proteins, especially soya. The role of the additives is known and briefly recalled: the silane is a coupling agent between the fibers and the binder, and also acts as an anti-aging agent; the oils are anti-dust and hydrophobic agents; the glycerol plays the role of plasticizer and prevents the pregelling of the sizing composition; silicone is a hydrophobic agent whose function is to reduce the absorption of water by the insulation product; the organic phosphate and the nitrogen compound act as an anti-fire agent. The sizing composition according to the invention is free of nitrogen compounds, which is advantageous because, as a result, the gas emissions generated during the heat treatment intended to crosslink the sizing composition do not contain nitrogen. The treatment of discharges at the outlet of the oven in industrial plants is thus easier to implement. The sizing composition is intended to be applied to mineral fibers, in particular glass or rock fibers. Conventionally, the sizing composition is projected onto the mineral fibers at the outlet of the centrifugal device and before they are collected on the receiving member in the form of a sheet of fibers which is then treated at a temperature permitting crosslinking. sizing and the formation of an infusible binder. The crosslinking of the sizing according to the invention is carried out at a temperature comparable to that of a conventional fornophenolic resin, at a temperature greater than or equal to 110 ° C., preferably greater than or equal to 130 ° C., advantageously greater than or equal to at 140 ° C, and more preferably at most equal to 300 ° C. The acoustic and / or thermal insulating products obtained from these glued fibers also constitute an object of the present invention. These products are generally in the form of a mattress 30 or a felt of mineral wool, glass or rock, or a veil of mineral fibers, also glass or rock, intended in particular to form a surface coating of said mattress or felt. The following examples illustrate the invention without limiting it. In these examples, the following are measured on the sizing compositions: - the pH, at a solids content equal to 30%, - the viscosity, in rnPa.s, at a solid content equal to 30 c / o, by means of a plane-plane rotational type rheometer with a shear of 100 s-1, at 25 ° C and 50 ° C, - the contact angle, on a CM210 glass plate with a content of materials solids equal to 30%, - the crosslinking start temperature (TR) and the crosslinking speed (V) by the Dynamic Mechnical Analysis (DMA) method which make it possible to characterize the viscoelastic behavior of a polymeric material. The procedure is as follows: a sample of Whatmann paper is impregnated with the sizing composition (solids content of the order of 30%), then it is fixed horizontally between two jaws. An oscillating element provided with a device for measuring the stress as a function of the deformation applied is disposed on the upper face of the sample. The device makes it possible to calculate the modulus of elasticity E. The sample is heated at a temperature ranging from 20 to 250 ° C. at a rate of 4 ° C./min. From the measurements, the variation curve of the modulus of elasticity E (in MPa) is established as a function of the temperature (in ° C.) whose general shape is given in FIG. values corresponding to the crosslinking start temperature (TR), in ° C, and the slope corresponding to the crosslinking speed (V), in MPa / ° C, - the mass loss by thermogravimetric analysis (TGA). The sizing composition is deposited in an aluminum cup, heated at 110 ° C for 60 minutes, then at 190 ° C for 10 minutes. 25 mg of the remaining residue is taken from the cup and placed in an alumina crucible. The crucible is placed in a device that continuously records the mass variation as a function of time for a temperature cycle ranging from 25 to 700 ° C at a rate of 10 ° / min. On the recorded curve, mass loss is determined at 200, 300 and 400 ° C.

EXAMPLES 1 TO 7 Sizing compositions comprising the constituents shown in Table 1 (in parts by weight) are prepared. The reference sizing composition (denoted Ref.) Is representative of the state of the art described in WO 2012/172262. The sizing compositions are prepared by adding the alkali metal or alkaline earth metal salt of lignosulfonic acid in a vessel containing water under stirring until complete dissolution, and then successively introducing the other compounds with vigorous stirring up to to obtaining a stable emulsion. The solids content of the sizing compositions is equal to 30%. The results are given in Table 1. Examples 1 to 7 in accordance with the invention have a lower contact angle than the reference which results in better wetting of the glass fibers. Examples 3, 4, 6 and 7 have a lower crosslinking start temperature than the Reference. Calcium lignosulfonate (Examples 6 and 7) further provides a higher starting rate of crosslinking than the Reference. Table 1 Ex.

1 Ex.

2 Ex.

3 Ex.

4 Ex.

Ex.

6 Ex.

7 Ref. Sizing composition Sodium lignosulfonate (1) 95 - - 80 - - - - Magnesium lignosulfonate (2) - 95 - - 80 - - - Calcium lignosulfonate (3) - - 95 - - 80 60 - Ammonium lignosulphonate (4) - - - - - - - 60 Hydroxymethylfurfural 5 5 20 20 20 40 - Glucose - - - - - - 40 Diammonium phosphate - - - - - - - 5 Properties PH 7,8 3,4 4,8 7 , 1 3.2 4.7 4.8 6.4 Victim (mPa $) - at 25 ° C 5.4 3.1 3.9 2.9 2.2 2.9 4.1 3.8 - at 50 ° C 2.9 1.7 2.1 1.9 1.4 2.0 2.0 2.3 Contact angle (°) 19 19 18 18 13 16 11 24 Start temperature cross-linking TR (° C) 158 n. d. 128 115 n. d.

108 113 140 Start velocity crosslinking V (MParC) 7 n. d. 5.3 8.2 n. d.

11 19 8 Loss of mass (%) - at 200 ° C 3 4 3 3 4 3 4 2 - at 300 ° C 16 16 20 15 13 17 15 16 - at 400 ° C 30 36 34 30 33 30 25 26 Arbo N18 sold by Tembec (2) Arbo MGLS sold by Tembec (3) C12 sold by Tembec (4) T11N5 marketed by Tembec n. d. : not determined

Claims (9)

REVENDICATIONS1. Sizing composition for insulating products based on mineral wool, especially rock or glass, characterized in that it comprises - at least one alkaline or alkaline earth metal salt of lignosulfonic acid, and - at least one carbonyl compound of formula R - [C (O) R 1] x (I) in which: - R represents a hydrocarbon radical, linear, branched or cyclic, saturated or unsaturated, a radical containing one or more aromatic rings consisting of 5 or 6 carbon atoms, a radical containing one or more aromatic heterocycles containing 4 or 5 carbon atoms and an oxygen, nitrogen or sulfur atom, the radical R possibly containing other functional groups, in particular hydroxyl or alkoxy, in especially methoxy, - R1 represents a hydrogen atom or a C1-C10 alkyl radical, and - x varies from 1 to 10. 2. Composition according to claim 1, characterized in that the alkali metal is sodium or potassium, preferably sodium, and the alkaline earth metal is magnesium or calcium. 3. Composition according to claim 1 or 2, characterized in that R1 represents a hydrogen atom and x is at most equal to 6. 4. Composition according to Claim 3, characterized in that the carbonyl function is in the form of an acetal or a hemiacetal of the following formula (II): OR 2 R - C - OR 3 H in which R 2 represents an alkyl radical in C1-C10, and R3 represents a hydrogen atom or a C1-C10 alkyl radical. 5. Composition according to claim 3 or 4, characterized in that the carbonyl compound is chosen from the group consisting of acetaldehyde, propionaldehyde, dimethoxyethanal, butyraldehyde, in particular n-butyraldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, 2-hydroxyglutaraldehyde, 3-methylglutaraldehyde, adipaldehyde, sualaldehyde, sebacaldehyde, malaldehyde, fumaraldehyde, poly (acroleins), starch dialdehyde, furfural (2-furancarboxyaldehyde), 5-methylfurfural (2-methyl-5-furancarboxyaldehyde), hydroxymethylfurfural (2-hydroxymethyl-5-furancarboxyaldehyde), 2,5-furancarboxydialdehyde, vanilin and vanilin polymers, especially bis-vaniline, cinnamaldehyde and cinnamaldehyde polymers, phthalaldehyde, isophthalaldehyde, terephthalaldehyde and oligomers of the following formulas (III) and (IV): wherein: A represents a divalent radical -CH2-, -CH (OH) - or -CH2-O-C1-12-, n varies from 1 to 8, 20 (IV) in which n 'varies from 1 to 9. 6. Composition according to one of claims 1 to 5, characterized in that the alkali metal or alkaline-earth metal salt of lignosulfonic acid represents 10 to 95% of the weight of the mixture consisting of the alkali metal salt or alkali metal salt. lignosulfonic acid and the carbonyl compound of formula (I), preferably 20 to 80%, advantageously 30 to 70% and more preferably 40 to 60%. 7. Composition according to one of claims 1 to 6, characterized in that it further comprises the conventional additives hereafter in the following proportions calculated on the basis of 100 parts by weight of alkali metal salt or alkaline earth metal lignosulfonic acid and carbonyl compound of formula (I): 0 to 5 parts of silane, in particular an aminosilane, 0 to 20 parts of oil, preferably 4 to 15 parts, 0 to 30 parts of glycerol, preferably 0 to 20 parts, 0 to 5 parts of a silicone, 0 to 40 parts of an organic phosphate, preferably 0 to 30 parts. - 20 parts of an extender, in particular carbohydrates such as molasses or dextrin, and animal or vegetable proteins, especially soya. 8. Composition according to one of claims 1 to 7, characterized in that it is free of nitrogen compounds. 9. Acoustic and / or thermal insulating product based on mineral wool, in particular glass or rock, bonded with the aid of the sizing composition according to one of claims 1 to 8.