Insulation material

Abstract

The invention relates to a cellulose wool insulation used as thermal and acoustic insulation in buildings, comprising at least cellulose wool fibers produced by crushing and fiberizing recycled paper and / or cardboard or a corresponding raw material, and one or more boron-compound-free flame retardants. According to a preferred embodiment of the invention, the cellulose wool insulation comprises magnesium chloride as a flame retardant and fine-grained, powdered, particulate and / or corresponding clay, which are added to the cellulose wool by dry treatment during the manufacturing process thereof.

Description

[0001] INSULATION MATERIAL

[0002] The invention relates to a composition for producing an insulation material containing flame retardants for use in the thermal insulation of buildings , in particular cellulose wool , according to the preamble of the independent patent claim directed thereto .

[0003] BACKGROUND OF THE INVENTION

[0004] Cellulose wool is an ecological and recyclable insulation material having excellent thermal insulation properties and is commonly used as a thermal and acoustic insulation material in attic and ground floors , intermediate f loors , and external walls of buildings . Cellulose wool is a loosefiber, blowable insulation material manufactured from recycled paper or cardboard, such as newspapers , and it is widely used for building insulation due to its good insulation properties , environmental friendliness , and breathability . In the manufacture of cellulose wool , recycled paper or cardboard i s first shredded into fragments approximately the si ze of postage stamps , after which the shredded material is fiberi zed in a fiberi zer into a thermal insulation fiber mass having a particle si ze of approximately 0-4 mm . In the fiberi zer, chemicals such as flame retardants are added to the fiber mass as a dry treatment , wherein they are mechanically mixed with the thermal insulation fibers . The finished insulation material is then compressed into a compact package and delivered to the installation site to be mechanically blown into the structure to be insulated .

[0005] Cellulose wool is inherently an ecological insulation material . At present, however, flame retardants are generally used in cellulose wool to improve fire safety and prevent ignition of the material . Typically, flame retardants used include boron compounds such as boric acid or borax, aluminum sulfate , magnesium hydroxide , and / or ammonium polyphosphate . Among boron compounds , boric acid mixed with magnesium sul fate is commonly used as a flame retardant in cellulose wool . The typical amount of flame retardants in cellulose wool is approximately 10 wt% . Boron compounds are ef fective flame retardants that prevent the spread of fire and reduce smoke formation; however, there is a need to find ecological alternatives that are lower in cost and suf ficiently available .

[0006] Currently, flame retardants based on phosphates and silicone-based compounds have also been proposed . However , phosphate compounds may be reactive with other chemicals that may be used, such as mold inhibitors , and they may cause corrosion, thereby damaging metal parts in structures . In the case of cellulose wool , conformity i s veri fied in accordance with the testing program of the product standard, wherein corrosion properties related to flame retardants are tested as described in section EN 15101 / ANNEX E of the cellulose wool product standard . Furthermore , silicone-based flame retardants are currently relatively expensive and have limited fields o f application .

[0007] In prior art solutions , attempts have been made to replace the commonly used boron compounds as flame retardants in cellulose wool with alternative compounds . However, their use has so far involved challenges , such as causing corrosion to metal parts o f insulated buildings , which is particularly problematic when using phosphate-based or chlorine-containing materials . On the other hand, some materials currently in use involve other functional or usability-related problems , for example when the functionality of certain materials proposed as flame retardants is limited at the ignition temperature of wood, thereby restricting their use in wooden structures .

[0008] The obj ective of the present invention is to attain a decisive improvement over the problems described above and thereby substantially raise the level of current state o f the art . In order to attain this obj ective the invention is characteri zed by what is set forth in the characteri zing part of the independent patent claim directed thereto .

[0009] OBJECT OF THE INVENTION

[0010] The obj ect of the invention i s to present a thermal insulation material compri sing at least cellulose wool , a flame retardant , and clay . In the insulation material according to the invention, the flame retardant and the clay are preferably intended to be added to the cellulose wool during fiberi zation by dry treatment .

[0011] The basic idea of the invention i s to replace the boron- containing chemicals commonly used as flame retardants in cellulose wool , such as a mixture of boric acid and magnesium sul fate , with a composition that is more advantageous in terms of cost and ecology without impairing flame-retardant functionality . For this purpose , magnesium chloride and clay are added to the cellulose wool during fiberi zation by dry treatment in the insulation material according to the invention . DESCRIPTION OF THE INVENTION

[0012] The insulation material of the invention comprises magnesium chloride functioning as a flame retardant and fine-grained clay, which are added to cellulose wool by dry treatment during f iberi zation . Magnesium chloride i s in itsel f an economical and ef fective flame retardant that has a flame-retardant classi fication by the European Chemicals Agency (ECHA) , but due to its chlorine content , it causes corrosion of metals , which limits its use in cellulose wool employed as thermal insulation in buildings , as it may cause corrosion in nails , screws , or other metallic fastening structures . Magnesium chloride i s highly water-soluble and may form an electrical ly conductive electrolyte solution with water, thereby promoting oxidation of metals . Magnesium chloride is also a highly hygroscopic salt , meaning that it absorbs moisture from the surrounding air, whereby it may form a mixture o f moisture and salt on metal surfaces and maintain a humid environment , which increases the risk of corrosion, particularly in the case of steel and other iron-based metals . When dissolved in water, magnesium chloride produces chloride ions , which are highly reactive and can penetrate protective oxide layers on metal surfaces , damaging or destroying such oxide layers and promoting corrosion .

[0013] In the insulation material of the invention, in addition to magnesium chloride , fine-grained clay is added to the cellulose wool during the manufacturing process in dry form in order to prevent corrosion caused by magnesium chloride . In the insulation material of the invention, the clay used in connection with cellulose wool slows down the access of chlorine , in particular corrosion-causing chloride ions formed upon decomposition of magnesium chloride , to metal surfaces , thereby retarding corrosion . This is made possible in that the clay adsorbs chlorine and / or its compounds , reducing the concentration of free chlorine when magnesium chloride decomposes as it dissolves in water and / or absorbs atmospheric moisture due to its high hygroscopicity . Clay minerals have a high cation exchange capacity, whereby they can bind cations such as chloride ions , thereby reducing corrosion-promoting ef fects . Furthermore , during the blowing process of the cellulose wool , the added clay may form a protective layer on metal surfaces to prevent and / or slow down the access of chlorine to the metal surfaces in order to retard corrosion . Additionally, certain clay types , such as bentonite , have an extremely high water-absorption capacity, whereby adding clay to the cellulose wool makes it possible to reduce the amount of water on metal surfaces . Furthermore , for example the clay mineral glauconite , like many other clay minerals , contains a high amount of aluminum oxide and silicon dioxide , but also relatively high amounts o f iron, potassium, and magnesium, and has particularly good ion exchange properties .

[0014] The most important advantages of the cellulose wool insulation material and its f lame-retardant composition according to the invention include , first of all , low cost and ecological properties . The magnesium chloride used as a flame retardant in the insulation material according to the invention and the clay used in connection therewith are directly compatible with currently used manufacturing processes and equipment . As a preferred embodiment of the invention, the flame retardant , such as magnesium chloride , may be added to the cellulose wool fibers as an aqueous solution .

[0015] DETAILED DESCRIPTION OF THE INVENTION

[0016] The invention relates to an insulation material used as thermal and acoustic insulation in buildings , comprising at least cellulose wool fibers manufactured by crushing and fiberi zing recycled paper and / or cardboard or a corresponding raw material , and one or more flame retardants . According to a preferred embodiment of the invention, the insulation material comprises cellulose wool fibers , magnesium chloride used as a flame retardant , and fine-grained, powdered, particulate and / or corresponding clay, which are added to the cellulose wool fibers by dry treatment during the manufacturing process to produce the insulation material .

[0017] According to a preferred embodiment of the insulation material according to the invention, it preferably comprises 10-20 wt% , most preferably 12-15 wt% , o f magnesium chloride and 1-5 wt% , most preferably 2-3 wt% , of clay based on the total mass of the cellulose wool .

[0018] According to a preferred embodiment of the cellulose wool insulation according to the invention, the proportion of clay in the flame retardant is preferably 10-25 wt% , most preferably 15-20 wt% .

[0019] According to a preferred embodiment of the invention, the clay used in the insulation material comprises at least one of the following : an iron compound, a potassium compound, and a magnesium compound. As a further preferred embodiment of the invention, the clay further comprises iron in the form of iron(III) oxide, i.e. ferric oxide, potassium in the form of potassium oxide, magnesium in the form of magnesium oxide, aluminum oxide, and / or silicon dioxide .

[0020] According to a further preferred embodiment, said clay preferably comprises 4-7 wt% silicon dioxide, 15-20 wt% aluminum oxide, 4-8 wt% iron (III) oxide, 1-4 wt% magnesium oxide, and 3-7 wt% potassium oxide.

[0021] As a preferred embodiment of the cellulose wool insulation of the invention, the clay used in connection with the flame retardant comprises at least one of the following clay minerals: bentonite, kaolinite, glauconite, illite, sepiolite, montmorillonite, smectite, vermiculite, chlorite, palygorskite, ball clay, halloysite, saponite, beidellite, lizardite, nontronite, or a combination thereof .

[0022] According to a further preferred embodiment of the cellulose wool insulation according to the invention, it further comprises an additive added thereto during crushing and / or fiberization by dry treatment and / or as a liquid dispersion, the additive being one or more of the following materials: a mold inhibitor; a surfactant; a pest or insect control agent; and / or a corresponding material improving and / or protecting the properties of the cellulose wool.

[0023] The present invention relates particularly to mechanically blowable cellulose wool insulation, but also to the insulation material per se, which may be used for desired purposes . The insulation material according to the invention is also suitable , i f necessary, for manufacturing board insulation or for other intended uses . It is obvious that the invention is not limited to the embodiments presented or described above , but may be modi fied within the scope of the basic idea of the invention depending on circumstances by using materials best suited for the intended purpose in the cellulose wool insulation with respect to raw materials , flame retardant compositions , and additives .

Claims

CLAIMS1. An insulation material used as thermal and acoustic insulation, comprising cellulose wool fibers and magnesium chloride used as a flame retardant, characterized in that the insulation material further comprises clay for preventing corrosion-promoting effects of chlorine formed from the decomposition of magnesium chloride, and wherein said clay further comprises at least an iron compound, a magnesium compound, and a potassium compound .

2. The insulation material according to claim 1, characterized in that it comprises 10-20 wt%, preferably 12-15 wt%, of magnesium chloride and 1-5 wt%, preferably 2-3 wt%, of clay based on the total mass / volume of the insulation material.

3. The insulation material according to claim 1 or 2, characterized in that it further comprises at least one of the following additives: a mold inhibitor, a surfactant, and a pest control agent.

4. The insulation material according to any one of claims 1-3, characterized in that the iron compound is iron (III) oxide, the magnesium compound is magnesium oxide, and the potassium compound is potassium oxide.