FR2764597A1 - COMPOSITION OF MINERAL WOOL - Google Patents

Abstract

The invention concerns "bi-component" mineral fibres obtained by joint fibre drawing of two different mineral compositions, in particular two glass compositions based on SiO2, alkaline oxides and earth-alkaline oxides: the two mineral compositions have a coefficient of thermal expansion alpha with a difference DELTA alpha of at least 20.10<-7> K<-1>: they have a minimum viscosity fibre drawing temperature Tlog3 between 830 and 1010 DEG C; they have a working temperature level of at least 30 DEG C; they each comprise in all less than 3 wt. % of the following components; TiO2, ZnO, BaO, Li2O, and preferably less than 1 wt.% of each; they have in weight percent, differences in boron oxide B2O3 and in sodium oxide Na2O contents respectively such that: (i) DELTA B2O3 > 2 %, (ii) DELTA Na2O > 2 %.

Description

- 1 -

COMPOSITION OF MINERAL WOOL

The present invention relates to the field of artificial mineral wools. It relates more specifically to mineral wools intended for manufacturing thermal and / or acoustic insulation materials or soil-less culture substrates, and in particular those commonly referred to under the term

of glass wool.

The mineral wools of the glass wool type of interest to the invention are generally obtained by so-called internal centrifugation fiberizing processes, consisting, schematically, in pouring the vitrifiable raw materials, once in the molten state, inside centrifuges the peripheral strip of which is pierced with a large number of orifices, from which the molten mass is projected in the form of filaments which are entrained and drawn into fibers by a gas current of high temperature and speed at the periphery

centrifuges.

An adaptation of the previously described internal centrifugation technique has been developed, an adaptation consisting, again very schematically, in supplying with two glass fillets having different chemical compositions, each of the orifices of the fiberizing plate. The glass compositions being chosen so as to have different coefficients of thermal expansion, the fibers obtained are found to be "bicomponent" fibers which, on cooling, exhibit great flexibility, and a "curvilinear" appearance. final product a particularly airy appearance, particularly "swelling", with a high recovery of thickness after compression.

US Patents 2,998,620, WO-95/12554 and WO-96 / 34837.

- 2- Studies have also been carried out in order to develop the most judicious "pairs" of glass compositions to obtain the

sought-after property.

Thus, the aforementioned patent application WO-95/12554 describes combinations of two types of glass compositions, the difference between the thermal expansion coefficients of which is at least 20.10-7K. However, the two types of compositions retained have a temperature corresponding to a viscosity in poise equal to log 3, which is between 1010 C and 1121 C. Concretely, this temperature, called Tlog3, is an indicator for humans of the minimum fiberizing viscosity temperature art. However, the previous temperature range 1010-1121 C is particularly high, which is not without drawbacks in terms of fiber drawing: this implies in particular increased energy expenditure for the melting of raw materials, a risk of premature corrosion of the plates.

1 5 of fiberization.

The aforementioned patent application WO-96/34837, for its part, chose in particular to add oxides of the Li20, ZnO, BaO or TiO2 type to the compositions in order to best modulate the thermal expansion coefficients thereof, or else to use rates particularly high boron oxide for compositions with the lowest coefficient of thermal expansion. However, in either case, these choices lead to an increase in

notably the costs of raw materials.

The aim of the invention is to overcome these drawbacks, in particular by developing new combinations of mineral compositions which are capable, once bundled together, of exhibiting the desired wavy appearance thanks to a sufficient difference between their expansion coefficients. respective thermal. But the invention also seeks to ensure that the production of such fibers is feasible, industrially and economically, and in particular is not penalizing in terms of yield, cost of

production, energy costs or raw materials.

The subject of the invention is therefore "two-component" mineral fibers obtained by joint fiber drawing of two different mineral compositions, in particular two glass compositions based on SiO2, alkali metal oxides and -3 - alkaline earth oxides. They are defined by the following characteristics: O a) - the two mineral compositions have thermal expansion coefficients a exhibiting a difference Sa of at least 20.10-7 K-1 between the composition "above a" and the composition " at lower W ', and in particular at least 30.10-7 and even 40. 10 7 K-1, O b) - the two mineral compositions have a minimum viscosity temperature Tlog3 of between 830 and 1010 C, EO c) - the two mineral compositions have a working level defined by the difference between the minimum fiberizing viscosity temperature and the liquidus temperature of at least 30 C, in particular at least 40 C, 10 d) - the two mineral compositions each include in weight percentages , in all less than 3% of the following compounds: TiO2, ZnO, BaO, Li20, and preferably less than 1% of each of them, O e) - the two compositions exhibit, in weight percentages, differences in respective contents boron oxides B203 and sodium oxide Na2O such as: (i) A B203> 2% (ii) A Na2O> 2% According to the invention, the following relationship is also preferably obtained

(iii) 0% i A Na2O - A B2031 <5.

In the context of the invention, the term "A B203" in relation (i) is understood to mean the difference between the content of B203 as a percentage by weight of the composition "at lower oa" and the content of B203 as a percentage by weight of

the composition "above a".

Likewise, by A Na20 in equation (ii), we understand the difference between the Na20 content as a weight percentage of the composition "at higher W 'and the Na20 content as a weight percentage of the composition" at

lower E ".

In relation (iii), it is indeed the absolute value of the difference A Na2O - A B203 which is considered: here, the difference may in fact correspond to a positive or negative value. Furthermore, the temperature value Tmog3 -4 - corresponds to the temperature at which the composition (s) considered is (are)

(are) at a viscosity, expressed in poises, corresponding to log 3.

In view of all the characteristics stated above, the invention has in fact achieved a judicious compromise between the various properties sought for this rather particular type of fiber. Thus, characteristic a) guarantees that we will effectively obtain corrugated fibers, and therefore mineral wool exhibiting the particularly advantageous "swelling" from the thermal and mechanical point of view. Indeed, a minimum difference of 20.10-7K-1 between the two coefficients of thermal expansion is necessary. Preferably, an ASc of the order of 30 or

even 40 to 50.10-7K-1.

The characteristic b) states a range of advantageous temperature values Tlog3, because if they are below 1010 C, and rather between 850 and 1010 C, and in particular at least 860 C, or even possibly at least 890 C C, that is to say relatively low temperatures, which is obviously very interesting, both in terms of energy cost of fiberizing and of production tools. Indeed, the centrifugation plates are thus not too thermally stressed, and have normal wear.

without resorting to expensive materials suitable for high temperatures.

Preferably, the values of Tlog3 of two compositions are close, advantageously with a difference of at most 30 C, in particular at most 25 C, more particularly at most 20 C, to guarantee optimum compatibility.

of their fiberizing conditions.

Characteristic c) is a working level, previously defined, large enough to allow fiberizing under standard conditions. Of

preferably, this level is at least 40 C, and even advantageously at

above 50 C.

The characteristic d) goes in the direction of limiting the cost linked to the raw materials: in fact, the invention makes it possible to obtain fibers with the desired property, without having to resort to components in

quantities such that their cost would penalize the profitability of manufacturing.

Characteristic e) of the invention highlights the relationships (i) and (ii) between the Na 2 O and B 2 O 3 contents of the two compositions. The invention has in effect shown that sodium oxide and boron oxide have an influence on the coefficient of thermal expansion α, in similar proportions but in opposite manner, sodium oxide tending to increase. the coefficient a whereas the boron oxide tends to decrease it. Rather than adding very specific oxides to influence the coefficient (t, oxides having only this role and being generally very expensive such as Li20 or ZnO, the invention is therefore based on compositions with the usual constituents: I Sodium oxide and boron oxide are well known components for adjusting the viscosity of the composition, included among the fluxes and / or network modifiers in the mineral composition. The invention therefore attributes to them a secondary role, that of of "regulators> of the coefficient (x, of

so as to obtain the desired coefficient difference between the two compositions.

And what is astonishing is that this "second role" therefore led to choosing minimum differences between Na20 and B203 contents, defined by relations (i) and (ii), without these adjustments in Na20 contents. and B203 do not interfere with their primary function. It was thus possible to maintain, in parallel, values of Tlog3 and liquidus temperatures that were fully adapted to the standard conditions of fiberizing by internal centrifugation. On the contrary, it would have been possible to s Expect such adjustments to have unintended consequences on the "fibrability" of the compositions. In fact, one can "afford", within the framework of the invention, to choose two compositions whose contents of sodium oxide and boron oxide remain in proportions which are not necessarily unusual, since it is on deviations that

we reason.

It should be noted that the invention mainly emphasizes Na20 as an agent capable of increasing the coefficient (x, but that other alkali metal oxides can play this role, most particularly K20. In fact, it is preferred in the invention to use little or no K20, generally at most 10%, in particular at most 8% or 5% or 3%, because it comes from a raw material which tends to be a little more expensive than Na20. alkali metal oxides, it is therefore preferred in the invention to choose the relatively large ratio of the weight percentages Na 2 O / R 2 O. It is possible, without departing from the invention, -6 - to consider in relation (ii) not Na 2 O, but in fact the sum

(Na20 + K20).

Note also that the optional relation (iii) "<translates" the fact mentioned above, which is an opposite influence, but in similar proportions, of these two oxides. From the composition "at high (" to the composition "at low AC", the <"defect" in "boron oxide" is thus "compensated",

at least in part, by an "excess" of sodium oxide and vice versa.

It can be emphasized that, even in the "low ax" composition, which therefore happens to be the richer of the two in B203, it is preferred according to the invention to limit the boron oxide content to at most 20% by weight, a excessive boron oxide content which may prove to be penalizing in terms of material cost

firsts, in particular.

According to a variant of the invention, at least one of the mineral compositions comprises, in weight percentage, at least 0.5 to 1% of aluminum oxide. While it does not appear to have a significant influence on the coefficient of expansion ax, on the other hand providing a certain amount tends to improve the durability of the fibers, in particular with regard to water attack or durability. at high temperature. It may be preferable, however, to

limit the content to at most 3.5% by weight.

According to another variant of the invention, of course compatible with the preceding one, at least one of the two compositions comprises, in weight percentage, from 0 to 3% of P205, in particular either 0% of P205, or of 0.1 or of 0.5 to 2% of P205. This constituent can fulfill an interesting role: it is in fact known that it tends to positively influence the biodegradability of fibers, tested by suspension in a buffered medium simulating a physiological medium, without very significantly modifying the coefficient of thermal expansion a. It is therefore advantageous to use it in the compositions. A maximum rate of 3 or 2% is preferable, so as not to burden the costs of raw materials. According to another variant, still compatible with the preceding ones, at least one of the two compositions can comprise at most 3% of K20 and, preferably between 0 and 2% of this oxide. Indeed, the K20 plays a role of -7 - flux, like the Na2O, and tends to increase the coefficient ci as explained previously. However, it is preferable to limit the content thereof, by keeping the sum of the alkali metal oxide contents of each of the two compositions constant, since potassium oxide tends to be more expensive than sodium oxide. According to another variant compatible with the preceding ones, at least one of the compositions may contain from 0 to 3% by weight of Fe 2 O 3 (total iron expressed

in this form), and / or contain up to 3% by weight of fluorine.

According to another variant, compatible with all the previous ones, at

least one of the compositions may contain less than 3% by weight of BaO.

The invention defines below four main types of mineral compositions of glass type, denoted A, B, C, D and classified with a coefficient of thermal expansion (decreasing. The most advantageous combinations between two compositions belonging to different types In each of these families, and in all the compositions exemplified below, it should be understood that these compositions may optionally contain elements / oxides other than those explicitly mentioned. options mentioned above of the type P205, Fe203. It is also known to those skilled in the art of glass compositions that these can include, without limitation, also a certain content of impurities, generally

not more than 2% by weight.

The first family of compositions is said to be of type A. It has a coefficient of thermal expansion (a between 110 and 140.10-7 K1, and it comprises sodium oxide, boron oxide, optionally K20 in the following proportions, in weight percentage: - B203 <7%, preferably less than 6%, in particular from 0 to 4% or O to 3%,% - + Na20> 18%, preferably from 19 to 25%

- Na2O + B203 + K20 between 18 and 33%, in particular between 22 and 30%.

This sum (Na2O + B203 + K20) is an interesting index of the overall cost of raw materials necessary for the formulation. In fact, it can be considered that in the compositions according to the invention, the main constituents of which are the standard constituents of the glass compositions, it is sodium oxide and boron oxide which, by the amounts used and

their prices define a significant part of the overall cost of the composition.

Another important point is that this sum (Na20 + B203 + K20) largely determines the value of Tlo, 3 of the composition. Preferably, the type A composition comprises the following compounds, in weight percentages: SiO2 46 to 62%, preferably 48 to 60% Na2O 18 to 26%, preferably 19 to 25% B203 0 to 7%, preferably 0 at 4% A1203 0 to 8%, preferably 0 to 5% K20 0 to 8%, preferably 1 to 4% CaO 6 to 13%, preferably 7 to 12% MgO 0 to 5%, preferably 0 to 3 %

P205 0 to 3%

This series is interesting in that it targets compositions by

coefficient ax high or even very high, since, for some of the examples 1A-

18A which illustrate this family in the rest of this text, the coefficient (X

exceeds 130.10-7 K-1.

All the compositions of this family have two points in common: a high level of alkali metal oxides, and more particularly of sodium oxide, and a

level of boron oxide reduced, or even zero.

We can then distinguish several <sub-groups "in this family

according to different criteria linked to their compositions.

Thus, some have a significant aluminum oxide level, of the order of 5 to 8%, while others have a much lower or even almost zero level of aluminum oxide, of the order of 0.5 to 3%. Aluminum oxide tends to increase the durability of the fibers, an excessively high rate which may however not be desirable for other considerations: the invention therefore allows a wide choice in the proportion of alumina, while keeping values of ax and TIo93 in similar values, which can be seen in particular by comparing examples 11 A and 1 6A, or 14A and 16A

detailed below.

It is also possible to distinguish the compositions having P205, in particular between 0.5 and 2%, and those which do not. In fact, the presence of P205 can improve the biodegradability of fibers, especially if it concerns

compositions in which the level of alumina is significant.

One can also distinguish the compositions having boron oxide, in particular in modest proportions of the order of 1 to 3%, and those which

are devoid of it.

As regards the adjustment of the coefficient ac, it is in fact advantageous here to put little or no B203, since it tends to lower this coefficient. Its presence in these "high ac" compositions can however be justified by its

primary function of fondant.

The second family of compositions is said to be of type B. It has a coefficient of thermal expansion ax of between 100 and 109.10-7 K-1, and it comprises sodium oxide and boron oxide, and optionally Potassium oxide in the following proportions, in weighted percentage B203 2 3%, preferably> 4% and in particular from 4 to 7%, - Na20 <22%, preferably <20%, in particular between 16 and 20%, - Na20 + B203 + K20 between 1 5 and 28%, in particular between 1 8 and 25% Preferably, composition B comprising the following compounds, in weight percentages SiO2 56 to 65%, preferably 58 to 62% Na20 15 to 22 %, preferably 16 to 20% K20 0 to 3%, preferably 1 to 2.5% B203 3 to 10%, preferably 4 to 8% A1203 0 to 3%, preferably 1 to 2.5% CaO 6 at 10%, preferably 7 to 9% MgO O at 5%, preferably 1 to 4.5%

P205 0 to 3%

Note that this time, it is a minimum boron oxide level which is imposed, and, on the contrary, a maximum sodium oxide level. It is still more a question of a composition of the "high oc" type (although it is not excluded to make it play the role of a "lower a" composition, for example in association with a. composition of type A), but it covers a range of

coefficients a lower.

This is a family of compositions that is somewhat intermediate between the compositions with a very high level (a previously mentioned and the compositions with very low aL described below under the term of type D family. The level of Na20 tends to be a little lower than in family A, and on the other hand the presence of B203 is required. The sum (Na2O + B203 + K20) also tends to be lower than in family A. The third family of compositions is said to be type C. It has a coefficient of thermal expansion x between 76 and 99.10-7 K-1, and it comprises sodium oxide, boron oxide, and optionally potassium oxide in the proportions following, in weight percentage: '- B203> 10%, preferably> 11% and in particular between 11 and 16%, Na2O <18%, preferably from 15 to 18%

Na2O + B203 + K20 between 22 and 33%, in particular 25 and 30%.

Preferably, it comprises the following compounds, in weight percentages SiO2 52 to 64%, preferably 55 to 63% Na20 13 to 18%, preferably 14 to 18% K20 0 to 2%, preferably O to 1% B203 10 to 15%, preferably 11 to 15% A1203 0 to 4%, preferably 0.5 to 2% CaO 4 to 10%, preferably 4 to 8% MgO 1 to 6%, preferably 3 to 5% P205 0 to 3%, in particular 0 to 2% As for family B, this family of compositions is therefore somewhat intermediate in terms of coefficient ax. The compositions of this family preferably act as a "lower-ac composition", although it is not excluded from the invention that they may act as a "lower-ac composition".

high (a "in combination with a composition with an even lower value of a.

The compositions of family C tend to be richer in B203 and less rich in sodium oxides than those of family B. The sum of Na20 + B203 + K20 generally tends to be higher, because the increase in the level of B203 tends to be generally greater than the decrease in

level of Na20 (and / or K20).

The fourth family of compositions is said to be of type D. It has a thermal expansion coefficient ca between 60 and 75.10-7 K-1. It comprises sodium oxide, boron oxide, and optionally potassium oxide in the following proportions, in percentage by weight: - Na20 <1 3%, in particular between 8 and 1 3% or between 9 and 1 2%, B203> 13%, in particular between 14 and 21% or between 15 and 19%

Na20 + B203 + K20 between 21 and 32%, in particular between 25 and 30%.

Preferably, the inorganic composition "D" comprises the following compounds, in weight percentages: SiO2 53 to 62%, preferably 55 to 60% Na2O 8 to 15%, preferably 9 to 13% K20 0 to 3%, of preferably 0 to 1% B203 13 to 22%, preferably 15 to 19% A1203 0 to 3%, preferably 0.5 to 2% CaO 4 to 10%, preferably 4 to 7% MgO 1 to 9%, of preferably 3 to 8%

P205 0 to 3%

This family of compositions is thus aimed at very low coefficients (t, linked, for a large part, to a high level of boron oxide and a relatively moderate level of sodium oxide. It is therefore used in the invention as a composition " at lower ('. The sum (Na20 + B203 + K20) of this family of compositions does not differ appreciably from that of family C or

of family A, in particular.

This family of compositions can be divided into different sub-

groups. Thus, some of these compositions may contain P205 and not

- 12 -

others. Likewise, some of these compositions may contain little or no alumina (0 to 0.5% by weight) or a more significant content, for example of the order of 1 to 2 or 3%. Likewise, in this family, we tend to

preferably to use a fairly constant CaO content of the order of 3 to 8%.

On the other hand, it may be advantageous to modulate the level of MgO more widely, which can for example also be either of the order of 3 to 5%, so as to have an MgO / CaO ratio of the order of 1, or of the order of 7 to 9%, so as to have an MgO / CaO ratio rather of the order of 2, and so as to also have an overall content of alkaline earth oxides more

high, usually accompanied by a lower SiO2 content.

The fibers according to the invention therefore combine two compositions belonging to two different "types". Three combinations are all

particularly advantageous.

The first consists in associating a composition of type "A" as a composition "at higher a" with a composition of type "C" as a composition "at lower a", with preferably: (i) A B203 > 3%, in particular> 7%, preferably between 8 and 15%,

(ii) A Na 2 O> 4%, in particular> 5%, preferably between 5 and 11%.

The second consists in combining a composition of type <B "as a composition" at higher a "with a composition of type" D "as a composition" at lower a ", with preferably: (i) A B203 23%, especially> 7%, preferably between 8 and 14%,

(ii) A Na 2 O> 2%, in particular> 6%, preferably between 7 and 10%.

The third consists in combining a composition of type "A" as a composition "at higher t" with a composition of type "D" as a composition "at lower a", with preferably: (i) A B203 25%, especially> 9%, preferably between 10 and 19%,

(ii) A Na2O> 5%, especially> 8%, preferably between 8 and 15%.

The fourth consists in combining a composition of type C as a composition "at higher a" with a composition of type D as a composition "at lower a", with preferably: (i) A B203> 3%, in particular> 6%, preferably between 6 and 9%, - 13-

(ii) A Na 2 O> 3%, in particular> 6%, preferably between 6 and 10%.

It is also possible to envisage combining a composition of type A as a composition "at higher a" with a composition of type B as a composition "at lower (C"), with preferably: (i) A B203> 2%, preferably> 3% up to 8%,

(ii) A Na 2 O> 4%, preferably> 5%, in particular between 6 and 8%.

The fibers of the invention as described above can be applied to the manufacture of thermal insulation materials and / or

acoustics, and also in the manufacture of soil-less culture substrates.

The invention will be described in more detail below using examples of

non-limiting realization.

All the mineral wools described below are obtained by internal centrifugation, the technique of which has been adapted to allow fiberizing.

joint of two compositions.

In accordance with this "joint" internal centrifugation technique described in particular in US Pat. No. 2,998,620, a continuous fiberizing plate is fed with a stream of molten glass having a first given composition and with a stream of molten glass exhibiting a second. composition. These compositions are chosen according to the invention to exhibit significantly different ac coefficients. Under the effect of centrifugal force and the adapted design of the orifices with which the plate is fitted, two-component filaments are ejected from the orifices and then drawn using an annular burner generating a ring of hot gas under the 'plate. The fibers thus formed are then optionally impregnated with a sizing composition, annular blowing members then guiding the optionally sized fibers on a suction conveyor belt, the speed of which will make it possible to adjust the basis weight of the final product. The web thus formed is brought into an oven at 200 ° C. equipped with endless belts of lower and upper conformation (which makes it possible to crosslink the resin of the sizing composition if one has been used), and to conform the web to

the desired thickness and therefore the desired density.

- 14 -

The four tables below group together examples of compositions according to the four main families of compositions A to D explained above: CI table 1: type A compositions, examples 1 A to 18A, CI table 2 type B compositions, examples 1 B to 8B, O table 3 compositions of type C, examples 1 C to 1 2C, El table 4 compositions of type D, examples 1 D to 1 3D Each of these tables indicates: the composition of each of the compositions of the examples, as well as their temperatures Tlog3 and Tiiq in C,

their thermal expansion coefficients (a in K- '.

Fe203 should be understood as taking into account all of the iron oxides in the composition, as is accepted in this field.

In all these examples, the contents are to be understood in percentages by weight. When the sum of all the contents of all the i15 compounds is slightly less than 100%, it should be understood that the residual rate corresponds to the impurities and / or minority components not analyzed (for example traces of Fe203, TiO2, S03, ...). If, on the contrary, it is slightly higher than 100%, the reason stems from the tolerances allowed on

analyzes in this area.

- 15 -

TABLE 1

COMPOSITION (A "

EX. 1A EX. 2A EX. 3A EX. 4A EX. 5A EX. 6A EX. 7A EX. 8A EX. 9A

SiO2 56.52 53.48 54.64 51.5 56 54.5 56 50.5 53.5

A1203 4.7 4.6 4.65 7 6.5 7 4.5 7 7

CaO 7 7 7 9 9 8 9 9 9 MgO 2.1 2.05 2.1 2.5 2.5 2.5 2.5 2.5 2.5 Na2O 21.9 22 21.9 25 19 23 23 25 23

K20 1.1 1.1 1.1 2 2 2 2 2 2

B203 5.8 5.8 5.9 3 5 3 3 4 3

Fe203 - 1.4 O, 16 - - - - -

F 0.75 0.75 0.7 -

NiO 0.01 1 1

CoO - 0.85 0.85 - - -

P205 0.05 0.03 0.03 0 0 0 0 0 0

TOTAL 99.93 100.06 100.03 100 100 100 100 100 100

Tlog3 937 896 907 902 978 948 937 889 937

Tliq 860 860 870 - - - - - -

ca 117.10 '117.10' 116.10- '131.10-' 110.10 '123.10-' 123.10 '131.10-' 124.10 '- 16- TABLE 1 - continued

COMPOSITION "A"

EX. 1 OA EX.11A EX.12A EX.13A EX.14A EX.15A EX. 16A EX.17A EX.18A

SiO2 53 50 51 51 51 54.5 55 58.5 60

A1203 8 7 8 7 8 1.5 0.5 2.5 2.5

CaO 12 12 12 12 10 12 12 12 12 MgO 2 2 2 2 2 2 2.5 2 2.5 Na2O 22 25 25 25 25 25 25 22 22

K20 3 2 2 3 3 3 3 0 0

B203 0 0 0 0 0 0 0 1 1

Fe2O3 - - - - - - -

F NiO CoO

P205 0 2 0 0 1 2 2 2 0

TOTAL r 100 100 r 100 100 | 100 100 I 100 100 100 Tlog3 951 913 913 900 923 900 895 948 943 Tliq _ _ __ _ _ _ __ _ _ _ _ _ _.__ 5_ _ _ _ _ _ _ _ _ 122 _ a1

128.10- '138.10-' 137.10- '138.10- - - - -

a 128.10- "138.10-" 137.10 / 138.10- / 137.10- / 135.10- "134.10- / 122.10- / 120.10- / - 17-

TABLE 2

COMPOSITION "(B"

EX. 1B EX. 2B EX. 3B EX. 4B EX. 5B EX. 6B EX. 7B EX. 8B

SiO2 58 60 59.5 59.5 59 58 61 61.8

A1203 2.5 2 2.5 1 2.5 2, 5 7 2.5

CaO 9 9 9 9 9 9 9 6.9 MgO 4 3.5 4 4 4 4 2.5 2.5 Na20O 19 19 19 17.5 18 18 17.5 19, 6

K20 2 2 2 2 2 2 2 1.9

B203 5.5 4.5 4 7 5.5 6, 5 7 4.6

TOTAL 100 100 100 100 100 100 100 99.80

Tlog3 910 925 925 915 930 910 925 1003 Tliq - - - - - - - 890 oz 107.10107. 10- '107.10-' 100.10- '104.10' 103.10- '100.10-' 110.10 'Fold -Ji 18-

TABLE 3

COMPOSITION <(C "

EX. lC EX.2C EX.3C EX.4C EX.5C EX.6C SiO2 58 58.5 61 57.81 59 62.15

A1203 1 0.5 0.5 0.65 0.5 0.04

CaO 7 7 7 7.95 7 10.7 MgO 5 5 3.5 3.4 4.5 0.9 Na2O 14 14 14 17.9 14 13.75

K20 0 0 0 0.02 0 0.02

B203 15 15 14 11.9 15 12.15

BaO 0 0 0 0 0 0 BaO5 O O O O O O

P205 0 0 0 0 0 0

TOTAL 100 100 100 99.63 100 O99.71

Tlog3 956 956 983 929 960 989 Tliq 870 940 x 80.10 '80.10' 80.10- '98.10' 78.10 '85.10-' - - 19- TABLE 3 - Continued

COMPOSITION "C"

EX.7C EX.8C EX.9C EX.10C EX. 1 1C EX.12C

SiO2 58 60.5 52 55.2 53 55

A1203 1 1.5 2 1.35 1 1

CaO 7 7 8 7.6 10 9 MgO 4 3.5 7 3.1 7 7 Na20 15 15.5 15 17.85 15 15

K20 0 0 2 0.5 1 2

B203 15 12 12 12.2 12 1l 1 BaO 0 0 0 2.35 0 0

P205 0 0 2 0 1 0

TOTAL | 100 100 100 | 100.15 | 100 100

oA Io I o o 1 o o Tlog3 947 984 924 920 914 926 Tliq 850 _ 83.10 '87.10' 90.10- '99.10-' 90.10- j 90.10 'i -, I O'D O'1

- 20 -

TABLE 4

COMPOSITION "D">

EX. 1D EX. 2D EX. 3D EX. 4D EX. 5D EX. 6D EX. 7D

SiO2 56.32 57.5 59 59 58.5 57 59

A1203 2.7 1 0.5 1 1 2.5 1

CaO 8.4 8 8.5 9 9 9 9 MgO 3.4 4 5 3, 5 4 4 3.5 Na2O 9.7 11.5 12 10.5 10.5 11.5 11

K20 0.02 0 00 0 0 0

B203 19.29 18 15 17 17 16 16.5

P205O 0 0 0 0 0 D

TOTAL 99.83 100 100 100 J 100 100 J 100

Tlo93 1004 955 973 979 975 971 977 Tiq 970

70.10- '72.10-' 75.10 '70.10-' 70.10- '75.10-' 72.10- '

Pi ", 4 -J

- 21 -

TABLE 4 - Continued

COMPOSITION D "

EX.8D EX.9D EX.10D EX.11D EX.12D EX.13D

SiO2 59 59 57 55.5 53.5 55

A1203 1 1 2.5 0.5 0.5 1

CaO 8 9 9 8 9 8 MgO 4 4 4 8 8 7 Na2O 11 11.5 11.5 9 9 10

K20 0 0 0 0 0 0

B203 17 15.5 16 19 19 19

P205 0 0 0 0 1 O

TOTAL 100 100 100 100 100 100

Tlog3 977 978 971 949 938 941 Tliq_ c 70.10- '74.10-' 75.10 '62.10' 64.1066.10- '

- 22 -

The compositions of a given type are then combined with compositions of another type so as to comply with the conditions of the invention in terms of Na 2 O and B 2 O 3 contents and of coefficient a. The most advantageous combinations are those which combine compositions of type A with compositions of type C (combination "A + C"), combinations of type B with compositions of type D (combinations <B + D "), type A compositions with type D compositions ("" A + D "combinations). It is in fact the combinations which make it possible to ensure the most significant differences in coefficient (k combined with the smallest differences in TIog3. It is thus possible to obtain corrugated fibers without being <at the limit "both in terms of expansion difference

thermal and fiber drawing compatibility.

However, by carefully choosing the compositions, it is possible to combine compositions of type A and B or compositions of type C and D. It is noted that it is also possible to make combinations with compositions belonging to different families, but nevertheless having

fairly similar values of TIog3.

Thus: * from Table 1, we see that the compositions according to family A can exhibit Tlog3 ranging between 880 C and 990 C, * from Table 2, we see that the compositions according to family B can exhibit Tlog3 s' ranging between 890 C and 950 C, with even an example at approximately 1000 C, * of Table 3, it can be seen that the compositions according to family C can exhibit Tlog3 ranging between 900 C and 990 C, * and that finally from Table 4, it can be seen that the compositions according to family D can exhibit Tlog3 values generally between 920 C and 980 C, with even a value of around 1000 C for example 1D. (These ranges of Tlog3 are given only as an indication, and not limited to

each of the families).

Table 5 below highlights the most advantageous combinations, indicating for each of them the values of ANa20, AB203, ANa20-AB203 1 in weight percentages explained at the start of the

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present text, as well as the values of AcE in K- 'corresponding to the difference between the coefficients ca of the composition "at higher (W'" and of the composition "at lower a", and the values of A TIog3 in degrees C corresponding to the difference, in absolute values, between the temperature Tlog3 of the composition "at higher O" and that of the composition "at lower (".

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TABLE 5

Sa A Tlog3 ANa20 AB203 ANa2O- AB203 I "Combination A + C"

EX.1A + EX.1C 37.10- 19 7.9 9, 2 1.3

EX.4A + EX.4C 33.10- 27 7.1 8, 9 1.8

EX.5A + EX.5C 32.10- '18 5 10 5

EX.7A + EX.7C 40.10 '10 8 12 4

EX.10A + EX.7C 45.10- 4 7 15 8

EX.12A + EX.4C 39.10 '16 10 15 5

EX.14A + EX.4C 39.10- 6 7.1 11, 9 4.8

EX.12A + EX.9C 47.10- 11il 10 12 2 c Combination B + D

EX.2B + EX.2D 35.10- '30 7.5 13, 5 6

EX.8B + EX.1D 40.10- 1 9.9 14.69 4.79

EX.5B + EX.12D 40.10- '8 9 13, 5 4.5

-j -, j - 25- TABLE 5 - (continued) A ATIog3 ANa20 AB203 (ANa2O-AB203) "Combination A + D")

EX.6A + EX.13D 57.10 '7 13 16 3

EX.1A + EX.12D 53.10 '1 2.9 13.2 0.3

EX.1OA + EX.2D 56.10- 1 10.5 18 7.5

EX.18A + EX.11D 58.10 '6 13 18 5

* EX.5A + EX.9D 36.10 '0 7.5 10.5 3

"Combination C + D"

EX.4C + EX.11D 36.10- '20 8.9 7.1 1.8

EX.10C + EX.12D 35.10- '18 8.85 6.8 2.05

"Combination A + B"

EX.8A + EX. 6B 28.10 '21 7 2.5 4.5

EX.13A + EX. 4B 38.10- '15 7.5 7 0.5

-I have O1

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Of course, this table is absolutely not limiting of all the possible combinations. It exemplifies combinations which make it possible to obtain corrugated fibers, without encountering particular difficulties during fiber drawing, and without the raw materials necessary for the compositions placing too great a burden on their overall production cost. It can also be noted that even the compositions with a low coefficient (t, which are the richest in B203 have B203 contents which remain, by weight, less than%; and that even the compositions with a higher coefficient (x, which are the

richer in Na20, have Na20 contents which remain at most 25%.

The invention has therefore made it possible to reconcile obtaining mineral wool with very specific properties with acceptable manufacturing conditions.

industrially and economically.

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Claims (21)

1. "two-component" mineral fibers obtained by joint fiber drawing of two different mineral compositions, in particular two glass compositions based on SiO2, alkali metal oxides and alkaline earth oxides, characterized in that: J a) - the two mineral compositions have thermal expansion coefficients at exhibiting a difference Au of at least 20.10-7 K-1 between the composition "at higher ac" and the composition "at lower x", O b) - both mineral compositions have a minimum viscosity temperature TIog3 of between 830 and 101 0 C, I c) - the two mineral compositions have a working level defined by the difference between the minimum viscosity temperature and the liquidus temperatures of at least 30 C, O d) - the two mineral compositions each comprise in weight percentages, in all less than 3% of the following compounds: TiO2, ZnO, BaO, Li20, and preferably less than 1% of each of them, CI e) - the two compositions present in weight percentages, differences in the respective contents of boron oxides B203 and sodium oxide Na20 such as: (i) A B203> 2% (ii) A Na20> 2% 2. Mineral fibers according to claim 1, characterized in that the two compositions respect the relationship (iii) O <A Na20 - A B2031 <5. 3. Mineral fibers according to claim 1 or 2, characterized in that at least one of the two compositions comprises, in percent by weight, at less 0.5% of aluminum oxide A1203. 4. Mineral fibers according to one of the preceding claims, characterized in that at least one of the two compositions comprises, in weight percentage, at most 5%, in particular at most 3.5% of oxide aluminum A1203. - 28 - 5. Mineral fibers according to one of the preceding claims, characterized in that at least one of the two compositions comprises, in weight percentage, from 0 to 3% of P205, in particular from 0.5 to 2% of P205. 6. Mineral fibers according to one of the preceding claims, characterized in that at least one of the two compositions comprises, in percentage by weight, from 0 to 3% of Fe203 expressed as total iron. 7. Mineral fibers according to one of the preceding claims, characterized in that at least one of the two compositions comprises, in weight percentage, at most 8% of K20, and preferably between 0 and 4% of K20. 8. Mineral fibers according to one of the preceding claims, characterized in that one of the two mineral compositions, called "A", has a coefficient of thermal expansion (a between 1 1 0 and 140.1 0-K-1, and in that it comprises oxide of sodium, boron oxide, and optionally potassium oxide in the following proportions, as a percentage by weight: B203 <7%, preferably from 0 to 4%, Na2O> 18%, preferably from 19 to 25 % 18% <Na20 + K20 + B203 <33% 9. Mineral fibers according to claim 8, characterized in that the mineral composition "A" comprises the following compounds, in weight percentages SiO2 46 to 62%, preferably 48 to 60% Na20 18 to 26%, preferably 19 to 25 % K20 O at 8%, preferably 1 to 4% B203 O at 7%, preferably O at 4% A1203 O at 12%, preferably 0.5 to 5% CaO 6 to 13%, preferably 7 to 12 % MgO O at 5%, preferably O at 3% P205 0 to 3% 10. Mineral fibers according to one of claims 1 to 7, characterized in that one of the two mineral compositions, called <"B", has a thermal expansion coefficient a of between 100 and 109.10-7 K ', and in that it - 29 - comprises sodium oxide, boron oxide, and optionally potassium oxide in the following proportions, as a percentage by weight: - B203> 3%, preferably from 4 to 10%, - Na20 <22 %, preferably from 1 5 to 20% '-1 5% <Na20 + K20 + B203 <28% 11. Mineral fibers according to claim 1 0, characterized in that the mineral composition <"B" comprises the following compounds, in weight percentages SiO2 56 to 65%, preferably 58 to 62% Na20 15 to 22%, preferably 1 6 to 20% K20 0 to 3%, preferably 1 to 2.5% B203 3 to 10%, preferably 4 to 8% A1203 0 to 8%, preferably 0.5 to 4% CaO 6 to 10%, preferably 7 to 9% MgO O to 5%, preferably 1 to 4.5% P205 0 to 3% 12. Mineral fibers according to one of claims 1 to 7, characterized in that one of the two mineral compositions, called "C", has a thermal expansion coefficient ax of between 76 and 99.10-7 K- ', and in that it comprises sodium oxide, of boron oxide, and optionally potassium oxide in the following proportions, in percentage by weight: - B203> 9%, preferably from 10 to 16%, 'Na20 <18%, preferably from 1 5 to 1 8% - 22% <Na20 + K20 + B203 <33% 13. Mineral fibers according to claim 1 2, characterized in that the mineral composition "C" comprises the following compounds, in weight percentages SiO2 52 to 64%, preferably 55 to 63% Na20 13 to 18%, preferably 14 to 18% K20 0 to 2%, preferably 0 to 1% B203 1 0 to 1 5%, preferably 11 to 1 5% A1203 0 to 4%, preferably 0.5 to 2.5% - 30 - CaO 4 to 10%, preferably 4 to 8% MgO 1 to 6%, preferably 3 to 5% P205 0 to 3% 14. Mineral fibers according to one of claims 1 to 7, characterized in that one of the two compositions, called "D", has a coefficient of thermal expansion (O between 60 and 75.10-7 K-1, and in that it comprises sodium oxide, boron oxide, and optionally potassium oxide in the following proportions, as a weight percentage: - Na2O <13%, in particular between 8 and 13%, - B203> 13%, in particular between 14 and 21% Na20 + K20 + B203 between 21 and 32% 15. Mineral fibers according to claim 14, characterized in that the mineral composition "D" comprises the following compounds, in weight percentages SiO2 53 to 62%, preferably 55 to 60% Na2O 8 to 15%, preferably 9 to 13 % K20 0 to 3%, preferably 0 to 1% B203 13 to 22%, preferably 15 to 19% A1203 0 to 3%, preferably 0.5 to 2% CaO 4 to 10%, preferably 4 to 7 % MgO 1 to 9%, preferably 3 to 8% P205 0 to 3% 16. Mineral fibers according to claims 8 or 9 and 12 or 13, characterized in that they combine a composition of type "A" as a composition "at higher (x" with a composition of type "C" as a composition "at lower c", with preferably (i) A B203> 3%, especially 27% (ii) A Na20> 4%, especially> 5% 17. Mineral fibers according to claims 10 or 11 and 14 or 15, characterized in that they combine a composition of type "B" as a composition "at higher a" with a composition of type "D" as a composition "at lower (", with preferably - 31 - (i) A B203> 3%, especially> 7% (ii) A Na20> 2%, especially> 6% 18. Mineral fibers according to claims 8 or 9 and 14 or 15, characterized in that they combine a composition of type "A" as a composition "at higher ca '" with a composition of type "D" as a composition "at lower a", with preferably (i) A B203> 5%, in particular> 9% (ii) A Na20 2 5%, in particular> 8% 19. Mineral fibers according to claims 12 or 13 and 14 or 15, characterized in that they combine a "C" type composition as a "higher az" composition with a "D" type composition as a "lower (a" composition), preferably with (i) A B203> 3%, in particular> 6% (ii) A Na20> 3%, in particular> 6% 20. Mineral fibers according to claims 8 or 9 and 10 or 1 1, characterized in that they combine a composition of type "A" as a composition "at higher (C" with a composition of type "B" as a composition "at lower a", with preferably (i) A B203> 2%, especially> 3% (ii) A Na20> 4%, especially> 5% 21. Application of fibers according to one of the preceding claims to the manufacture of thermal and / or acoustic insulation material or of soilless culture substrates.