SI9520005A - Man-made vitreous fibre wool - Google Patents

Abstract

The production and physiological dissolution rate of mineral wool formed of MMV fibres containing 35-66 % SiO2, up to 10 % Al2O3, 10-45 % CaO, 2-30 % MgO, up to 10 % FeO, 0-7 % Na2O + K2O and 0-10 % TiO2 is improved by including both P2O5 and B2O3 in the composition.

Description

ROCKWOOL INTERNATIONAL A / S

501 Hovedgaden 501

2640 Hedehusene (DENMARK)

ARTIFICIALLY MADE OF GLASS FIBERS

The present invention relates to artificial fiberglass wool (MMVF) containing iron and a relatively high amount of alkaline earth metals and a low amount of alkali metals, commonly known as rock, slag or basalt wool.

Different types of MMV fibers are known.

It is known that when manufacturing conventional glass fibers, components that provide boric oxide (borate) are included in the glass melt. Glass and glass melt can improve this. However, raw materials containing borate are expensive and usually not even added, if possible, especially if the product contains iron and has a low alkali content and a high alkaline earth content than conventional melt stones, rocks and slag.

Glass wool products typically have a relatively high alkali metal content (often above 13% Na20 + K2O). For the purposes of this specification, all analyzes are expressed in terms of mass relative to the total composition calculated as oxides. Glass fiber and glass wool are usually iron-free, but Road also contains boron. Typically they contain less than 7%

AI2O3 «However, E-glass is a fibrous or other non-wool product and may have a lot of aluminum and little or no alkali metal. JP-A-50090719, for example, describes an Esteklo containing 15-16% Al2θ3 »9.5-10.5% & 2θ3 i ⁿ 5% P2O5. It is free of iron and sodium.

EP-A-9418 describes glass fibers that may be wide

-2 range of optional components, including iron, boron and phosphorus. None of the compounds shown as examples contain both boron and phosphorus and all have more than 13% alkali metal oxide.

W093 / 07741 describes fibers for use in horticulture containing 0 to 4% P7O5, above 13% Na20 and up to 8% ^^ 2 ^ 3 · 82θ3 ' ^venc iar total amount of impurities (including all θ2θ3' included) may be present ) should not be greater than 1%.

EP-A-412878 describes glass wool having a high alkali metal content (above 13%) and containing borate. It is iron free. Phosphorus is an optional component. This is allegedly incorporated to improve the solubility of the fibers.

We are concerned with improving the solubility of fibers in those wools, which are commonly referred to as mineral, stone, slag or basalt wool, and which typically contain iron, low aluminum (below 10 l), low alkali metal (below 7%) and a significant amount alkaline earth metals (above 12%).

It was suggested that it would be appropriate to provide such wools in which MMV fibers are soluble in physiological medium, especially in the fluid of urban plantations and parks.

It is known that the composition of a fiber can significantly affect its solubility. WO87 / 05007, for example, illustrates that fibers with a low alumina content, especially with less than 10 wt.% Of alumina in the composition, have improved solubility in a physiological environment. It is also known that the incorporation of phosphorus can improve solubility in a physiological medium. This was exemplified in the case of stone wool fibers, for example, in EP-A-459,897. This report reports stone wool fibers containing 1 to 10% phosphorus as P7O5. It is said that this component provides solubility in physiological

-3media. It can be assumed that by increasing the amount of phosphorus in this range, the solubility increases.

During the manufacture of MMVF wool, the components that make up the fibers are melted in a furnace, such as an electric, shaft, tub, or dome. This creates a melt that can then be processed into fibers. Typically, the melt has a melting point of about 1,400 to 1,600 ° C and is then heated in an oven above that temperature. It has been found that the incorporation of significant amounts of phosphorus into the melt can lead to some problems. For example, phosphorus can evaporate in the oven, leading to difficulty in controlling the composition. In particular, increasing the amount of phosphorus can adversely affect the viscosity and properties of the melt. This increases the risk of melt separation (containing iron and low or low C alkali metals and low aluminum), separation of the phases, and a constant stagnation. This leads to the formation and accumulation of solid or slag material in or on the machine used to extract the melt and convert the melt into fibers, and can cause an increase in the formation of fine grains during the fiber forming process to reduce material yield and increase costs .

It would therefore be appropriate to develop MMVF wool with solubility characteristics of the type as would be expected from such wool due to the use of relatively high phosphorus content, while avoiding manufacturing problems associated with relatively high phosphorus content.

The tendency of these problems is that they increase with the phosphate content of the melt. Problems can occur, for example, when phosphorus levels are increased by more than 5%. In some furnaces, up to 10% phosphate may be used, but in general it is undesirable for processing purposes to include more than this.

Even at low levels of aluminum oxide and in particular, Ce

-4 melt with very low levels of aluminum oxide cannot be guaranteed, however, the dissolution rates of the fibers are not as high as would be desirable at these levels of phosphate.

It would therefore be appropriate to improve the solubility of MM V fibers in physiological medium without the need to use quantities of phosphate leading to processing problems.

Fibers containing phosphorus and boron are mentioned in WO94 / 23801, of which this application takes priority.

According to the invention, we provide MMVF wool made from fibers made from a composition (in oxides by weight, with iron expressed as FeO), containing:

S i 0 7 35-66% A1 9 0 3 up to 10% CaO 10-45% MgO 2-30% FeO up to 10% N a 2 0 + K 2 0 0-7% T i 0 ₂ 0-10% P 7 0 3 + 8 2 0 3 and other elements -

and which includes both, P _? 0 3 and 8 ₂ 0 3.

It is surprising to note that the use of a melt containing phosphate and borate can give fibers with adequate physiological solubility made from the melt with a combination of favorable processing, viscosity and temperature characteristics, especially if the amount of AI2O3 is low.

It is noted that an upper limit of 10 t in the amount of phosphate helps to reduce manufacturing problems, especially phase separation. The amount is preferably 6% or less and is usually below 5 We find that the incorporation of borate increases the physiological solubility of the fibers without the need to use larger amounts of phosphate and to allow the use of phosphate even in quantities below 5%, while maintaining adequate physiological solubility. It is further noted that the additional advantage of borate is that it enhances the physical properties of the melt, especially helping to reduce the melt melting point by reducing the risk of phase separation.

We also find that the use of boron in phosphorus-containing fibers results in improved fiber properties. For example, tensile strength, elastic modulus and length-to-diameter ratio can be improved. The tensile strength may be> 700 MPa. The elastic modulus of fibers can be <150 GPa. The length-to-fiber ratio may be> 700, especially if the fibers are made with a cassette rotary machine.

At 1400 ° C, the melt viscosity of the composition is preferably 10-70 poises, especially 15 to 30 poises.

At pH 7.5, the dissolution rate of the fibers is preferably at least 30 nm / day and especially at least 50 or at least 60 nm / day when measured by the stationary layout of the method described in Environmental Health Perspectives, Vol. 102, Supplement 5, October 1994, pages 83-86.

The wool of the invention may be prepared by any known route. The invention also provides a process for the manufacture of MMVF wool made from fibers having the composition as defined above, the method comprising preparing the raw materials for the production of the composition, determining the furnace, placing the raw materials in the furnace and heating them to a temperature between 1,400 ° C. and 1,600 ° C to produce the melt, process the melt into fibers and collect the fibers as wool.

In this process we find all the advantages in the processing characteristics discussed above. The wools of the invention are preferably made according to the process of the invention.

In the process of the invention, the raw materials used to make the melt can be any known raw material that provides components for the composition. Raw materials that can be used include, for example, diabase, cement, clay, olivine sand, sand sand, waste foundry sand, waste, c o1 emanite and other boron-containing materials, converter slag, blast furnace slag, electric arc furnace slag, iron oxide, rock wool scrap, asbestos waste, lime, soda, glass waste, dolomite, bauxite, iron silicate, kaolin, calcium phosphate, quartz sand and other known melt components.

The composition of the melt and therefore the composition of the manufactured fibers preferably contains at least 45%, often at least 47 or 48% S1O2 · The amount is usually below 64 or 65 t, preferably below 60%. often the amount of S1O2 is from 53.5 to 64

The composition preferably has a low concentration of aluminum oxide, typically below 6% and preferably below 4%. In general, it is very expensive to provide raw materials that do not contain aluminum oxide at all. Thus, Al 2 ^ 3 is present to some degree, usually in amounts of at least 0.5%, although generally the amounts of aluminum oxide are kept as low as possible, preferably below 3 or 2%. Quantities 1-4% are often measurable.

The composition typically comprises at least 5%, usually at least 10% and preferably at least 15% of the alkaline earth metal oxides (CaO and MgO). The quantity is generally not more than 50%. The CaO content is preferably in amounts between 10 and 35%. In some formulations, amounts of 10-20% are preferred, and in others, 15 to 30% are preferred. MgO is usually present in an amount of at least 1%, often 5 to 20, preferably up to 20%. It can be, for example, in the range 5-15 I.

The composition contains iron and the amount measured as FeO is up to 10% (by weight) relative to the total composition. Preferably, the iron is present in amounts of at least 0.5 or 1%. quantities of up to 4% are often suitable, but the amounts may be up to 9 or 10%, for example in the range of 6.5-9%.

The composition may contain alkali metals (Na 2 O and K 2 O) in amounts of 0 to 6 w or 7%. In general, Na 2 O is present in amounts from 0 to 4 and 1 0 is present in amounts up to 2%. Typically, each is present in an amount of at least 0.1%, but both are optional and may be omitted.

Phosphate is usually present in the composition in amounts of between 0.5 and 10, measured as PiOc and often in the range of 3 to 6%. For processing purposes, it is desirable to keep the amount of phosphate as low as possible, although sufficient to cause it. suitable dissolution effect. The amount of phosphate is preferably at least 0.5% but below 5% (for example up to 4.5%), more preferably below 4%. It is usually at least 2% or 3%

Borate is mixed in effective amounts up to 10 measured as 82O3. The quantity is preferably greater than 0.5 or 1 Generally, it should be added sufficiently to increase the rate of saline adequately, but the inclusion of large quantities of borate results in the use of very expensive raw materials. Quantities of borate below 5% (for example 4.5 and less) can give good results at an economical price, but sometimes we prefer quantities up to 7% or 8%. The quantity must be large enough to give a useful effect, and is usually above 0.5 or 1% and preferably at least 3%. The quantity θ2 ° 3 -ΐθ for economic reasons is usually below the quantity ^ 2 ^ 5 ·

T1O2 is optional, if present, its amount '8 is usually 0.1 to 2%. The melt composition may additionally comprise 0 to 20% of other constituents, such as BaO, ZnO, Zr02> F2 'MnO,

Li20, SrO. The total amount of other constituents is usually no higher than 5% or maximum 10%.

The melt and fiber composition contains a particular priority:

SiO2 45 64%, preferably 47-60 or 48-60%

A1203 0.5 to 4 ° F,

CaO 10-35%

MgO 5-20%, preferably 5-15 or 7-15 ° and FeO 1-10%, preferably 1 to 9%

At ₂ 0 0 to VŽ

K ₂ 0 0 to 2?

Ti0 ₉ 0 to 2%

P2O5 at least 0.5 but preferably less than 5%,

B 2 0 at least 0.5%, but preferably below 5%, of the other elements 0 to 5%, with all percentages being by weight relative to the overall composition and the iron oxides measured as FeO.

The raw materials are placed in peC where they are heated to a temperature between 1,400 ° C and 1,600 ° C in order to make the melt. They are generally heated to a minimum of 1,450 ° C, preferably between

1,450 and 1,540 ° C, mostly about 1,480 ° C to 1,520 ° C.

The furnaces that can be used in the present invention to produce the melt to be converted into fibers include domed furnaces, oil or gas fired shaft or tub furnaces or electric furnaces. The invention is particularly useful in these furnaces, although the composition also shows advantages when other known types of furnace are used. Preference is given to furnaces in which significant amounts of air are flowing. Slag formation and any evaporation problems can be minimized by the invention.

The melt is processed into fibers in any known manner. Especially

... g may be processed into fibers by casting into a fast-rotating shingle having essentially a horizontal base and perforated side walls from which they emerge as fibers or by casting on one or more rotating wheels. Wheel or. all wheels are mounted on separate horizontal axes. The melt poured onto the circumference of a rotating wheel is ejected as fibers, although a single wheel may be used, a cascade system is preferably used, in which it is poured onto the initial rotor of a series of rotating rotors, each arranged around a different , essentially horizontal axes, and is positioned such that the melt is thrown from the starting rotor to the next rotor or to each subsequent rotor in a row so that the mineral fibers are dumped from the rotor or each subsequent rotor into the collecting chamber. Any known machine may be used to process mineral melt into fibers so as to produce wool, but it is a particularly preferred machine described in our patent publication W092 / 06047.

The fibers can then be collected as a net or multilayer net. The net may be cross-linked to form a multilayered net. The multilayered veil can be combined into the desired MMVF wool product in a known manner.

Typically, a multilayered veil contains a binder. This can be, for example, a syringe between fibers before being collected as a net or a multilayer net,

The wool may be in the form of molded multilayer fabrics or other elements, or it may be in the form of flakes or granules of mineral wool fibers or in the form of objects made of such flakes or granules.

MMVF wool can be used for any purpose common to MMVF wool, for example as a horticultural breeding aid, for sound or thermal insulation and protection, for resistance and protection against fire and as a filler, or

-10-reinforcement.

The following are examples of suitable compositions (determined by X-ray fluorescence analysis and calculated as mass fractions) and their dissolution rate at pH 7.5 in nm per day. Each composition can be melted in a dome furnace and processed into fibers as in W092 / 06047.

Within the scope of the invention, compositions 1, 2, 3 and 4, while 1A, 18, 2A, 3A and 4A are approximate comparisons and show that boron omission reduces the rate of dissolution. Comparative compositions without borate tend to form slag, especially those with high phosphorus content.

For R0CKW00L INTERNATIONAL A / S 501 Hovedgaden 501 2640 Hedehusene (DENMARK);

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Claims (1)

1. Mineral wool made from MMV fibers with a composition expressed as not having a n and a n content of oxides in the total composition, indicated by the complexion that Si0 ₂ Al ₂ 0 ₃ CaO MgO FeO 35-66% to 10% 10-45% 2-30% to 10% N a ₂ 0 + W ₂ 0 0-7% Ti0 ₂ 0-10% ^P 2 ° 5 ⁺ 8 ₂ θ3 and other elements up to 20 % and n which includes both, P ₂ 0g and 8? 0 ₃ . 2. Wool v according to claim 1, characterized by a complexion, Yes jo do 4% A1 ₂ 0 ₃ in that each of P ₇ O _{3 or} B ₇ 0 ₃ to 10 G. 3. Wool v according to claim 1 or claim 2, OZ oppressed .s t one that it is 53.5 to 65% Si0 ₂ , is 10-30% CaO, it is 5 to 20% MgO and n is up to 9% FeO. 4. Wool v according to claim 1, marked s ten, Yes sesta- in a includes S and 0 2 53.5-64% (by weight) A! ₂ 0 ₃ up to 4% (by weight) CaO 10-20% (by weight) MgO 10-20% (by weight) FeO 6.5-9% (by weight) ^p 2 ° 3 ⁺ B ₂ 03 to 20% by weight, each pa is up to 10 %. 5. Wool v according to claim 1, marked s ten, Yes sesta- va includes S and 0. 53.5-65% (by weight) Al ₂ 0 ₃ to 4% (by weight) CaO 15 -30% (by weight) MgO 5- 15% (by weight) FeO to 4 § (percentage by weight) W ₂ ° 3 + B ₂ 0 ₃ to 20 l (weight), each is up to 10 t. 6. Wool in accordance with claim 1, characterized by a complexion, Yes sesta- va includes P ₂ 0 ₃ and B 2 ° 3 ^1ri Si0 ₂ 45 to 60% Al ₂ 0 ₃ 0.5 to 4% CaO 10 to 35% MgO 5 to 15 Š FeO 1 to 10 1 At ₂ 0 0 to 4% k ₂ o 0 to 2? Ti0 ₂ 0 to 2% other h elements 0 to 5% 7. Wool in compliance with any of the foregoing claims, marked with tan to contain Ρ ₂ θ5 ^{in an} amount of 1 to 5% in in an amount of 1 to 10, preferably 1 to 5 ^b 2 ° 3 Wool according to any one of the preceding claims, characterized in that the quantity P ₂ 0 ^ θ · ^{Β is} up to ^B and / or the amount is 8 ₂ 0 ₃ θ · ^B up to · 5 · Wool according to any one of the preceding claims, characterized in that it has a dissolution rate of at least 30 nm / day at pH 7.5. A process for making MMVF wool as defined in any one of the preceding claims, characterized in that it comprises the preparation of raw materials for the manufacture of the composition, the determination of the furnace, the heating of the furnace livers to a temperature between 1,400 'C and 1,600 ° C, melt is prepared, melt is processed into fibers and fiber is collected as wool. A method according to claim 9, characterized in that the furnace is a domed oven.