FR2917745A1 - SIZING COMPOSITION FOR MINERAL WOOL COMPRISING THE PRODUCT RESULTING FROM THE OXIDIZING CLEAVAGE OF UNSATURATED OIL AND INSULATING PRODUCTS OBTAINED. - Google Patents

Abstract

The present invention relates to a sizing composition for thermal and / or acoustic insulation products, based on mineral wool, in particular glass or rock, which is in the form of an aqueous emulsion comprising: less a product resulting from the oxidative cleavage of an unsaturated oil, plant or animal, selected from aldehydes, peroxides and mixtures of these compounds, - at least one co-reactant containing at least one hydroxyl, amine or amide function. also relates to a process for preparing the sizing composition and insulating products based on mineral fibers thus obtained.

Description

SIZING COMPOSITION FOR MINERAL WOOL COMPRISING THE PRODUCT

  RESULTING FROM THE OXIDIZING CLEAVAGE OF UNSATURATED OIL AND INSULATING PRODUCTS OBTAINED

  The present invention relates to the field of insulation products, thermal and / or acoustic, based on mineral wool, in particular glass or rock, and an organic binder comprising condensates from the product resulting from the oxidative cleavage of unsaturated oil. The invention more particularly relates to a sizing composition capable of crosslinking to form said organic binder, which contains the product resulting from the oxidative cleavage of an unsaturated oil and a co-reagent, the process for preparing said sizing composition, and the resulting insulating products. The manufacture of insulating products based on mineral wool generally comprises a step of manufacturing the wool itself, which can be implemented by various methods, for example according to the known technique of internal or external centrifugal fiber drawing. 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 under the form of filaments. At the outlet of the centrifugal device, the filaments are stretched and driven to a receiving member by a gaseous stream having a high temperature and speed, to form a sheet of fibers (or mineral wool). To ensure the assembly of the fibers together and allow the web to have cohesion, is projected on the fibers, in the path from the output of the centrifugal device to the receiving member, a sizing composition containing 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 properties Specific features include dimensional stability, tensile strength, compression thickness recovery 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. anti-dust, ... 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 must 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 resin and additives mentioned above.

  In terms of regulation, 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 stage or subsequently - as little as possible of compounds which 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 ability to crosslink in the aforementioned thermal conditions, these resins are soluble in water, have a good affinity for mineral fibers, especially glass, and are relatively inexpensive. These resols are obtained by condensation of phenol and formaldehyde, in the presence of a basic catalyst, in a formaldehyde / phenol molar ratio generally greater than 1 so as to promote the reaction between phenol and formaldehyde and to reduce the phenol content. residual in the resin. The condensation reaction between phenol and formaldehyde is operated by limiting the degree of condensation of the monomers, to avoid the formation of long chains, little hydrophilic, which reduce the dilutability. As a result, the resin contains a certain proportion of unreacted monomer, in particular formaldehyde, the presence of which is not desired because of its proven harmful effects.

  For this reason, resole-based resins are generally treated with urea which reacts with free formaldehyde by trapping it in the form of non-volatile urea-formaldehyde condensates. The presence of urea in the resin also provides a certain economic advantage because of its low cost, because it can be introduced in relatively large quantities without affecting the qualities of use of the resin, including the mechanical properties of the final product , which significantly lowers the total cost of the resin. It has nevertheless been observed that, under the conditions of the temperatures to which the sheet is subjected to obtain the crosslinking of the resin, the urea-formaldehyde condensates are not stable and decompose, giving back formaldehyde and urea, in turn degraded. in ammonia, which are released into the atmosphere of the plant. As environmental protection regulations become more stringent, insulation manufacturers have to look for ways to further reduce unwanted emissions, particularly of formaldehyde. The object of the present invention is to provide a sizing composition for mineral wool-based insulating products which is free of formaldehyde, thus making it possible to have an alternative to resole-based sizing compositions.

  Another purpose is to provide a sizing composition developed from natural compounds from renewable sources, including plant. To achieve these objects, the present invention provides a sizing composition for insulating products based on mineral wool, especially glass or rock, which is in the form of an aqueous emulsion comprising - at least one product resulting from oxidative cleavage of an unsaturated oil, vegetable or animal, selected from aldehydes, peroxides and mixtures of these compounds, and - at least one co-reactant containing at least one hydroxyl, amine or amide function. The product resulting from the oxidative cleavage of an unsaturated oil, plant or animal, is obtained by a process comprising a step of oxidation of the double bonds of the oil followed by a step of cleavage of the oxidation products to form aldehydes and / or peroxides. The preparation of such a product is described in particular in EP 1 198 443 A1. Examples of vegetable oils that may be mentioned include wood oil, especially tung oil, sunflower oil, and cottonseed oil, palm oil, corn oil, mono-, di- and triglyceride oils such as rapeseed oil, linseed oil, soybean oil, oil olive oil, castor oil, mustard oil, peanut oil, and phenolic oils such as cashew nut oil. Preferably, the oil chosen is rapeseed oil.

  Examples of animal oil include herring oil, sardine oil, whale oil, tallow, especially beef, and lard. The oil may consist of one or more vegetable or animal oils, and a mixture of these oils. The first step of oxidation of the oil can be carried out by any oxidative method for cleaving the unsaturated bonds to form aldehydes and / or peroxides, for example by ozonolysis or using hydrogen peroxide, advantageously associated with a catalyst such as ferrous ions and salts of oxidizing metals. Preferably, the oxidation is carried out by ozonolysis.

  The oxidation can be carried out in the presence of a protic solvent such as water and alcohols which participates in the oxidation reaction and leads to the formation of hydroperoxides, or of an aprotic solvent such as a hydrocarbon, chlorinated or not, in which case the oxidation products are ozonides. In the second step, the oxidation products formed are subjected to cleavage to form aldehydes and / or peroxides, and optionally hemiacetals of these aldehydes in the case where the cleavage is carried out in the presence of an alcohol. The conditions necessary to obtain the cleavage of the oxidation products are well known to those skilled in the art; preferably the cleavage is carried out under reducing conditions, for example using a metal such as zinc, advantageously associated with an acid such as acetic acid (see EP 1 198 443 A1). According to a preferred embodiment, the product resulting from the oxidative cleavage is chosen from aldehydes. The co-reactant according to the invention is a compound capable of reacting with the product resulting from the oxidative cleavage of an unsaturated oil under the effect of heat to form a polymer network in the final binder. The co-reactant comprises at least one hydroxy, amine or amide function.

  The compound comprising at least one hydroxyl function is chosen from polyols such as glycols, especially alkylene glycols, in particular ethylene glycol and diethylene glycol, triols such as glycerol, and other polyols such as pentaerythritol. , d-sorbitol and carbohydrates, especially starch, preferably hydrolysed, phenol and polyphenols such as resorcinol, catechol, hydroxyquinone, phloroglucinol and mixtures of polyphenols, in particular of plant origin, such as than lignins and tannins. Resorcinol and tannins are preferred. The compound containing at least one amine function comprises at least one primary or secondary amine function. These compounds as well as the compounds comprising at least one amide function are chosen from urea, ethylene urea, thiourea, melamine, proteins, in particular plant proteins, dicyandiamide, carbohydrazide and acetoacetamide. In the sizing composition, the co-reactant represents 5 to 95% by weight of the oxidative cleavage product of the unsaturated oil, preferably 10 to 50%, and preferably 15 to 45%. The sizing composition may further comprise an acidic or basic catalyst whose function is to adjust the starting temperature of crosslinking. The acidic catalyst is selected from sulfonic acids, especially substituted aromatic sulfonic acids such as para-toluene sulfonic acid. The basic catalyst is selected from alkali metal hydroxides and alkaline earth metal hydroxides, preferably sodium hydroxide.

  The amount of catalyst introduced into the sizing composition can represent up to 5% of the weight of the oxidative cleavage product of the unsaturated oil and the co-reactant, and preferably from 0.30 to 1.6%. According to a preferred embodiment, a basic catalyst is used which has the additional advantage of improving the stability of the emulsion under which the sizing composition is found. The amount of basic catalyst is preferably 0.4 to 1.1% by weight of the oxidative cleavage product of the unsaturated oil and co-reactant. If the sizing composition does not already contain urea, ethylene urea, carbohydrazide, dicyandiamide or acetoacetamide as a co-reactant, it may comprise one or more of these compounds as agent for increasing the rate of crosslinking of the sizing composition. Advantageously, this agent is urea. The amount of this agent in the sizing composition generally represents at most 20% of the weight of the product resulting from the oxidative cleavage of the unsaturated oil and the co-reactant, preferably between 1.5 and 15% and advantageously between 3 and 10%. By varying the amounts of catalyst, in particular basic, and the abovementioned compounds, in particular urea, it is possible to adjust the crosslinking conditions as well as possible and to obtain a good compromise between the temperature at which the composition of the sizing begins to crosslink and the speed of crosslinking. By way of indication, a suitable conventional formophenolic resin has a crosslinking temperature greater than or equal to 130 ° C., preferably greater than or equal to 140 ° C. and a crosslinking rate of between 3 and 4 GPa / C measured under the experimental conditions exposed. further. As indicated above, the sizing composition is in the form of an aqueous emulsion comprising fine droplets of product resulting from the oxidative cleavage of unsaturated oil, preferably having a predominantly submicron size. The fact that the sizing composition is in the form of emulsion has many advantages, in particular: having a fluid sizing composition, which makes it possible to be able to project it easily onto the mineral fibers, in particular by using spray techniques. It is also noted that the viscosity of the sizing composition remains low even when the solids content is important: thus the viscosity of the sizing composition at 30% solids is less than or equal to 100 mPa.s, preferably less than 20 mPa.s, and advantageously between 5 and 10 mPa.s. - have a good wetting of the fibers and a homogeneous distribution of the constituents of the sizing at the junction points thereof, and to reduce to a minimum the phenomena of pre-gelling before the heat treatment in order to obtain the final binder. The sizing composition according to the invention may furthermore comprise the conventional additives hereafter in the following proportions calculated on the basis of 100 parts by weight of product resulting from the oxidative cleavage of unsaturated oil and co-reactant: 0 to 2 parts of silane, in particular an aminosilane, 0 to 20 parts of oil, preferably 4 to 15 parts. 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; oils are anti-dust and hydrophobic agents. The process for preparing the sizing composition is an object of the present invention. It comprises the steps of: a) mixing the product resulting from the oxidative cleavage of unsaturated oil, animal or vegetable, selected from aldehydes, peroxides and mixtures of these compounds and the co-reactant, optionally in the presence of a acidic or basic catalyst and the accelerator of the crosslinking rate, with water b) treat the mixture thus obtained under conditions for forming an aqueous emulsion.

  Step a) is carried out at a temperature below 80 ° C. in order to avoid a reaction between the product resulting from the oxidative cleavage of the unsaturated oil and the co-reactant, with the consequence of increasing the viscosity of the mixture. Preferably, the temperature is between 20 and 60 C.

  More preferably, the mixture under a) is carried out with stirring in order to allow good homogenization of the constituents used. Stage b) of forming the emulsion may be carried out by any means known to those skilled in the art, in particular by subjecting the mixture to vigorous stirring, for example in a reactor stirred at a speed of the order of 500 to 2500 revolutions per minute. It has been found that the step of forming the emulsion does not require the presence of a surfactant. The conditions must make it possible to obtain a stable emulsion for a time sufficient to allow the application to the mineral fibers, especially at least 10 minutes, preferably at least 30 minutes. Step b) can be applied immediately to the mixture or after a period of storage and shortly before spraying on the mineral fibers.

  The sizing composition is intended to be applied to mineral fibers, in particular glass or rock fibers. In a conventional manner, 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 the crosslinking of the 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 formophenolic resin, at a temperature greater than or equal to 110 ° C., preferably greater than or equal to 130, and advantageously greater than or equal to 140 ° C. vs.

  The acoustic and / or thermal insulating products obtained from these sized fibers are also an object of the present invention. These products are generally in the form of a mattress or felt of mineral wool, glass or rock, or a veil of mineral fibers, also glass or rock, intended in particular to form a coating surface of said mattress or felt. These products are characterized by a better heat resistance compared with conventional formophenolic resins, in particular in the temperature range of from 200 to 420 ° C., preferably from 300 to 400 ° C. The following examples make it possible to illustrate the invention without however, limit it. In these examples, the following are measured: the crosslinking start temperature (TR) and the crosslinking speed (V) by the Dynamic Mechanical Analysis (DMA) method which makes it possible to characterize the viscoelastic behavior of a polymeric material. The procedure is as follows: the sizing composition (solids content of the order of 30%) is deposited on a glass slide, then a second glass slide of the same dimensions as the first is applied to the composition of gluing and the set of two blades is fixed horizontally between two fixed jaws. On the upper face of the assembly, there is an oscillating element connected to a device for measuring the stress as a function of the applied deformation which 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 / minute. 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. 1, and the values of the temperature are determined. starting point of crosslinking (TR), in degrees, and the crosslinking speed (V), in GPa / C.

Figure 1

  E (MPa) Slope: crosslinking speed V Beginning of crosslinking TR Temperature (C) - mass loss by thermogravimetric analysis (DTA): the sizing composition is deposited in an aluminum cup, heated at 110 ° C. for 60 minutes then at 180 ° C for 10 minutes. 10 mg of the residue remaining in the cup are removed and placed in an alumina crucible which is then placed in an apparatus which continuously measures the loss of mass during a temperature cycle ranging from 25 to 700 ° C. at a rate of 10 C / minute. On the recorded curve, the loss of mass is determined at 200, 300 and 400 C. EXAMPLES 1 to 7 Sizing compositions comprising the constituents shown in Table 1 are prepared. RSO aldehydes (Rape Seed Oil) are triglyceride aldehydes obtained by ozonolysis of rapeseed oil under the conditions of example 1 of patent EP 1 198 443 A1.

  The RSO aldehydes and resorcinol are introduced into a vessel maintained at 40 ° C., with stirring, for a time sufficient to obtain complete dissolution of the resorcinol in the aldehydes. The sizing compositions are prepared by successively introducing into a container water, urea, sodium hydroxide and the mixture of aldehydes of RSO and resorcinol. The container is sealed and subjected to vigorous stirring until a stable emulsion is obtained. The properties of the sizing compositions listed in Table 1 are evaluated in comparison with a conventional sizing composition containing a formophenolic resin and urea (Reference) prepared according to Example 2, Test 1 of WO 01/96254 A1. The crosslinking start temperature (TR) of the sizing compositions of Examples 1 to 7 is very close to that of the reference. It is noted that for a given amount of sodium hydroxide, the addition of urea makes it possible to significantly increase the rate of crosslinking.

  Example 7 has a viscosity lower than that of Reference for the same solids content (30%), which is particularly interesting in terms of application to mineral fibers, especially when it is carried out by spraying. Example 7 also has a lower contact angle than that of the reference which denotes a better wetting ability of the fibers by the sizing composition. Example 7 shows a lower mass loss than the Reference at temperatures of 200, 300 and 400 C which results in a better thermal resistance for insulation products treated with the sizing composition. Table 1 Ex.

1 Ex.

2 Ex.

3 Ex.

4 Ex.

Ex.

6 Ex.

7 Ref. Composition 7.7 7.7 7.7 7.7 7.7 7.7 7.7 - Triglyceride aldehydes (RSO) (g) Resorcinol (g) 2,3 2,3 2,3 2,3 2, 2,3 2,3 2,3 - NaOH (3 wt.%) (G) 1.07 1.33 1.33 1.33 1.60 1.60 1.60 - Urea (40% w) (g) 0.6 0 0.20 0.60 0 0.20 0.60 - Water (g) 15.91 15.47 15.53 15.67 15.23 15.29 15.43 - Properties 148 151 152 149 159 151 149 145 Start-up temperature nTR (C) Cross-linking speed V (GPa / C) 1.19 1.02 1.68 2.56 1.60 1.67 2.10 3.58 Viscosity at 25 ° C (mPa. $) (1) n. d n. d n. d n. d n. d n. d 6.7 8.0 Viscosity at 50 C (mPa $) (1) n. d n. d n. d n. d n. d n. d 6.9 6.0 Contact angle () n. d n. d n. d n. d n. d n. d 8 10 Loss of mass (%) n. d n. d n. d n. d n. d n. d 0.53 2.47 at 200 ° C. at 300 ° C. d n. d n. d n. d n. d n. d 4.32 16.41 A 400 C n. d n. d n. d n. d n. d n. d 15.15 37.11 (') emulsion or solution at 30% solids n. d. : not determined

Claims (16)

  1. Sizing composition for insulating products based on mineral wool, in particular rock or glass, characterized in that it is in the form of an aqueous emulsion comprising - at least one product resulting from the oxidative cleavage of unsaturated oil, vegetable or animal, selected from aldehydes, peroxides and mixtures of these compounds, and - at least one co-reactant containing at least one hydroxyl, amine or amide function.   2. Composition according to Claim 1, characterized in that the product resulting from the oxidative cleavage of unsaturated oil is chosen from aldehydes.   3. Composition according to claim 1 or 2, characterized in that the vegetable oil is chosen from wood oil, sunflower oil, cottonseed oil, palm oil, corn oil. mono-, di- and triglyceride oils such as rapeseed oil, linseed oil, soybean oil, olive oil, castor oil, mustard oil, peanut oil, and phenolic oils.   4. Composition according to one of claims 1 or 2, characterized in that the animal oil is selected from herring oil, sardine oil, whale oil, tallow, including beef, and lard.   5. Composition according to one of claims 1 to 4, characterized in that the co-reactant is selected from polyols such as glycols including alkylene glycols, in particular ethylene glycol and diethylene glycol, and triols such as glycerol, and other polyols such as pentaerythritol, d-sorbitol and carbohydrates, especially starch, preferably hydrolysed, phenol and polyphenols such as resorcinol, catechol, hydroxyquinone, phloroglucinol and mixtures of polyphenols, especially of plant origin, such as lignins and tannins, compounds containing at least one primary or secondary amine function, or at least one amide function such as urea, ethylene urea, thiourea , melamine, proteins, in particular plant proteins, dicyandiamide, carbohydrazide and acetoacetamide.   6. Composition according to one of claims 1 to 5, characterized in that the co-reactant is 5 to 95% by weight of the cleavage oxidant unsaturated oil, preferably 10 to 50%, and preferably 15 to 45% .   7. Composition according to one of claims 1 to 6, characterized in that it further comprises an acidic or basic catalyst.   8. Composition according to Claim 7, characterized in that the acidic catalyst is chosen from substituted aromatic sulfonic acids such as para-toluenesulphonic acid and in that the basic catalyst is chosen from alkali metal hydroxides and hydroxides. alkaline earth metals, preferably sodium hydroxide.   9. Composition according to one of Claims 7 or 8, characterized in that the catalyst represents up to 5% of the weight of the oxidative cleavage product of the unsaturated oil and the co-reactant, and preferably of 0.30. at 1.6%.   10. Composition according to one of claims 1 to 9, characterized in that it further comprises at least one accelerating agent of the crosslinking rate selected from urea, ethylene urea, carbohydrazide, dicyandiamide and acetoacetamide, in an amount of not more than 20% by weight of the product resulting from the oxidative cleavage of the unsaturated oil and the coreaactant, preferably between 1.5 and 15% and advantageously between 3 and 10%.   11. Composition according to one of claims 1 to 10, characterized in that it further comprises the additives hereafter in the following proportions calculated on the basis of 100 parts by weight of product resulting from the oxidative cleavage of unsaturated oil and co-reactant: 0 to 2 parts of silane, in particular an aminosilane, 0 to 20 parts of oil, preferably 4 to 15 parts.   12. A method for preparing a sizing composition according to one of claims 1 to 11, characterized in that it comprises the steps of: a) mixing the product resulting from the oxidative cleavage of unsaturated oil, animal or plant, chosen from aldehydes, peroxides and mixtures of these compounds and the co-reactant, optionally in the presence of an acidic or basic catalyst and of the agent for accelerating the crosslinking rate, with water b) treating the mixture thus obtained under conditions making it possible to form an aqueous emulsion.   13. The method of claim 12, characterized in that step a) is performed at a temperature below 80 C, preferably between 20 and 60 C.   14. The method of claim 12 or 13, characterized in that step b) is performed in a stirred reactor at a speed of the order of 500 to 2500 revolutions per minute.   15. Acoustic and / or thermal insulation 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 11.   16. Veil of mineral fibers, especially glass or rock, glued using the sizing composition according to one of claims 1 to 11.15.