IE44706B1 - Fire-proofing preparation and fire-proofed aritcles - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE The invention concern? a flame retardant composition components of lignocellulosic particles. The compositionignifugeante according to the invention is characterized in qu'ellecomprend for each 100 parts by weight of composition, offrom 20 to 75 parts by weight of boric acid, 15 to 75 weight partiesen a substituted halogenated organic compound selected Inthe group consisting by chlorinated paraffins, the decabromo diphenyl, decabromodiphenyl ether, bis-dibromopropylether octachlorodiphényle, the tribromophenoxy-2-3 dibromopro-pane 2-4-6, and mixtures thereof, and from 5 to 45 parts by weight of mineral unoxyde with flame retardant properties. It estutilisable for fireproofing elements of lignocellulosic particles monolayer or multilayer. In the latter case, the flame retardant composition may only be incorporated qu'auxparticules lignocellulosic intended to externesdesdits layer elements.

Description

The present invention relates to a composition for fire-proofing articles made of lignocellulose particles such as panels and plates, and to articles fire-proofed with such a composition.

The production cf articles made of lignocellulose particles has been known for a long time. The method consists, generally speaking, of agglomerating under pressure a mat composed of one or more layers of particles of wood, linseed waste or like material associated with an adhesive mixture generally consisting for part of synthetic resin and of adjuvants such as a hardener. Must frequently, the articles made of iignocellulose particles are formed from a plurality Of layers, generally three layers, with two external layers of mat sandwiching an intermediate layer having lignocellulose particles which are usually of largpr dimensions than those of the outer layers.

Such articles are used principally in the building industry. With safety standards for protection against fire becoming more and more strict in most countries, it has become necessary to fire-proof these articles.

Research Undertaken in order to improve the resistance to fire of these articles has led to the incorporation therein of products such as boric acid and its salts or ammonium salts as in the case of French Patents Nos. 1,223,575 and 1,444,833. Other fire-proofing products, such as urea (French Patent No. 2,171,071) or certain halogenated Τ Ο — *“ compounds known· as Tire-proofing agents for plastics (and described in Preach Patent So. 2,057,456/ have been incorporated in the whole of tne mat of lignocellulose particles. The incorporation of ail tnese compounds has made it possible tc improve the fire resistance of the lignocellulosic articles. However, it does not render the articles fire-preof and it sometimes impairs the ohysico-mechanical characteristics cf the articles. The ammonium salts which have tc- he incorporated in high proportions in order to obtain good fire resistance cause a considerable loss in tha physico-mechanic characteristics and more particularly render the articles less waterproof. Although boric acid and its salts whan used alone cause a lower deterioration in the properties of the articles, good fire-proofing cf the articles is not obtained, whatever the proportion of the boric acid or salt thereof. Moreover, the introduction of the elaborate fire-proofing agents in the whole of the mat often makes the cost of the articles prohibitive.

The aim of the present invention is a fire-proofing composition which, when incorporated in the lignocellulo.se particles and by virtue of the synergy of its components, makes it possible to produce very highly fire resistant lignocellulosic articles whilst retaining the physico25 mechanical properties of these articles and improving their waterproofness. The use of this preparation makes it. possible to obtain articles classed as Ml according to standards NFP 92,501 and HEP S2.5O7 of October 1975.

The fire-proofing composition of the present inven30 tion comprises the following components expressed as percentages by weight of the total compositionί to 75% of boric acid, to 75% cf a halogenated organic compound. to 45/ of an inorganic oxide.

This composition can be associated with the lignocellulose particles in an amount of 16 to 40 parts by weight per 100 parts by weight of the lignocellulose particles, the amount of composition incorporated in an article to be fire-proofed being a function of the chosen composition.

The halogenated organic compounds are preferably brominated and/or chlorinated. They may be aliphatic and/or aromatic. They may also be used alone or as a mixture. Examples of suitable such compounds are the chlorinated paraffins, decabromodiphenyl, decabromodiphenyl ether, bis-dibromopropyletheroctachlorodiphenyl, 2,4,6tribromophenosy-2,3-dibromopropane. The chlorinated paraffin with 70/ chlorine is particularly appropriate for the purposes of the invention.

The inorganic oxide included as an ingredient can be any such oxide known for its fire-proofing properties. Specially good results are obtained with antimony oxide.

As is known in the case of using fire-proofing preparations containing boric acid, it is possible to add to the preparation described a derivative of boron such as borax, borocalcite or colemanite, in order to facilitate the industrial manufacture of the articles made of ligno25 cellulose particles.

The present invention is applicable to the fireproofing, not only of single-layered articles, but also multi-layered articles of lignocellulose particles. In this latter case, excellent results are obtained by associating with the lignocellulose particles intended for one or both of the external layers of the article, preferably 16 to 40 parts by weight of the preparation 4 7 0 6 - 5 according to the invention, per IOC parts by weight of &ry particles, while the lignocellulose particles used to wake the interior layer (whether one or more) are associated with conventional fire-proofing products. It is well-known that the rate of incorporation in an article such as a panel is a function of the £ire-proofing composition chosen. By way of trample, it has been found that boric acid associated with the li-j-nccellulose par-ieles of the internal layer or layers of the article in an amount of 5 to 20 parts by weight per 100 parts nf dry particles gives excellent results.

The firs-proofing composition cf the invention and the conventional fire-proofing agent used for the internal layers (in the case cf multilayered articles) are respect15 ively mixed before agglomeration w'ah the lignocellulose particles intended respectively for the external layers and for the internal layers. They »~a.y be incorporated before, during or after the operation of gluing the lignocellulose particles. The gluing technique is one which it is believed will be well known to those skilled in the art. It consists cf mixing the lignocellulose particles with an adhesive mixture. The adhesive mixture is customarily composed of a synthetic resin and of adjuvants such as a hardener or water.

The synthetic resins currently employed are, inter alia, thermosetting resins such as the urea-formaldehyde and melamine-urea-formaldehyde resins. The quantities of synthetic resin used are generally from 7 to IS parts by weight per 100 parts by weight of dry lignocellulose particles. The adjuvants used are those customarily used and sold commercially for the manufacture of products of agglomerated lignocellulose particles.

Good distribution of the fire-proofing products in the glued mixtures is essential to produce agglomerated products of excellent quality. In order to facilitate this distribution, it may be advantageous to associate one or more Inorganic dispersing agents with the fire-prcofing composition according to the invention and with the fireproofing product intended respectively for the lignocellulose particles of the outer layers and of the inner layer of the agglomerated articles. These inorganic dispersing agents are most frequently used in the form of hydrates, the most common being silica and alumina.

The glued and fire-proofed mixtures according to the invention are treated according to the customary methods of manufacture of agglomerated articles. Employing, for example, the apparatus described in The Official Plastics and Rubber (Journal) April 1974 (no 222) page 236, agglomerated articles with excellent resistance to fire can be prepared for mixtures such as those previously described. Usually, in the case of multiple-layers, a quantity of glued mixture intended for the outer layer is spread, the quantity calculated as a function of the thickness v?hlch it is desired to obtain for the said outer layer. Then, still in quantities calculated as function of the thickness required, this first layer is covered with a glued mixture intended to form the inner layer of the agglomerated article.

Lastly, the inner layer is covered with a glued mixture intended to form the other outer layer in a quantity chosen as a function of the final thickness required.

This sandwich is then compressed while heating. The pressing times are variable and may be from 5 to 20 minutes, according to the thickness and the mass volume of the panel, at a temperature of from 140 to 180°C, at a pressure 4 7 0 6 of from 10 ίο 45 bars.

The Sallowing Sxsmplss serve to illustrate the invention. The fire resistance tests were performed according to standard K3?S S2.5O1 of October 1975 and the classification according to standard N.TP 92,507. The quantities are given in parts by weig.it, unless otherwise stated. iSlriMPLE I k panel of wood particles is made in three layers by separately nixing ir. a gluing machine, ths mixture intended fcr the outac layers, and the mixture intended for the centre. The wood particles are glued by means of an adhssave mixture having 515» by weight of dry cine. The respective fire-proofing compositions ure then carefully mixed with tht glued particles. In this example the adhesive mixture used is based tn urea-formaldehyde rosin.

The composition of the various layers is as follows: Centre dry wood particles loo boric acid 10 dry glue 11 Outer layers dry wood particles 100 boric acid 8 chlorinated paraffin, 70% chlorine 10 antimony oxide 7.5 dry glue it Tne panel is manufactured to n 50-40 proportion of centre/outer layers. It is baked for 10 minutes at 150°C at a maximum pressure of 30 bars. - 8 3 The panel obtained has a density of 770 kg/m and a thiolcness of 19 lam.

The fire resistance tests on unsanded faces result in this panel being classified in category IU.

EffiKPLE 2 A panel of wood particles in three layers is prepared. In contrast to Example 1, the respective fire-proofing compositions are incorporated in the wood particles before gluing. The adhesive mijcture contains 52% by weight of dry glue based on melamine-urea-formaldehyde resin.

The composition of the various layers is as follows; Centre dry wood particles boric acid dry glue Outer layers dry wood particles boric acid chlorinated paraffin, 70% chlorine antimony oxide dry glue The panel is manufactured to a 60/40 proportion of the centre/outer layers. Xt is baked for 5 minutes at 165°C at a maximum pressure of 30 bars.

The panel obtained has a density of 754 kg/m and a thickness of 19 mm.

The fire resistance tests on lightly sanded faces results in this panel being classified in category ML.

EXAMPLE 3 A panel of wood particles in three layers is prepared. 100 100 .7 4.3 4 7 0 s - 9 In this example, the respective fire-proofing compositions are incorporated in the wood particles at the same time as the adhesive mixture. The adhesive mixture contains 50.5% by weight of dry glue based on urea-formaldehyde resin.

Tha composition of the various layers is as follows:Centre dry wood particles 100 boric acid 10 colemanite 2 alumina hydrate 0,6 dry glue 12 Outer layers dry wood particles 100 boric acid 12 colemanite 3 alumina hydrate 0,8 chlorinated paraffin, 70% chlorine 6 antimony oxide 4 dry glue 15 The panel is manufactured tc a 6S/32 ratio of centre/ Q outer layers. It is bated for 7 minutes at 160 C at a maximum pressure of 35 bars.

The panel obtained has a density of 740 kg/m and a thickness of 20. o mm.

The fire resistance tests after sanding of fche faces down to a final thickness cf 19 mm result in this panel being classified in category M 1.

EXAMPLE 4 A panel of wood particles in three layers is prepared. As in Example 1, the respective fire-proofing compositions - 10 are incorporated with the glued wood particles. She adhesive mixture contains 50% by weight of dry glue based on urea-formaldehyde.

The composition of the various layers is as follows: Centre dry wood particles 100 boric acid 12 dry glue 10 Outer layers dry wood particles 100 boric acid 13 decabromodiphenyl 5 antimony oxide 5 dry glue 10 The panel is manufactured to a 60/40 proportion of centre/outer layers. It is baked for 10 minutes at 150°C under a maximum pressure of 30 bars.

The panel obtained has a density of 740 kg/m and a thickness of 19 mm.

The fire resistance tests result in this panel being classified in category Ml.

EXAMPLE 5 A panel of linseed waste in one layer is prepared.

As in Example 1, the fire-proofing composition is incorporated with the glued particles of linseed waste. The adhesive mixture contains 50% by weight of dry glue based on urea-formaldehyde.

The composition of the single layer is as follows: -ι ‘17 U 6 dry particles of linseed «aste 100 boric: acid 12 chlorinated paraffin, 70% chlorine 6 antimony oxide 5 dry gins 12 The panel is based for 10 minutes at 155 c at a maximum pressure of 40 bars.

·? The panel obtained has a density of £30 iK'/ra*' and a 10 thickness of 19 nm.

The fire‘resistance tests result in this panel being classified in category H 1.

Claims (13)

1. A composition useful for fire-proofing articles made of lignocellulose particles, the composition comprising the following components expressed as percentages by weight of the total composition: 20 to 75% of boric acid, 15 to 75% of a’halogenated organic compound, and 5 fo 45% of an inorganic oxide.

2. A composition according to Claim 1, wherein the halogenated organic compound is selected from a chlorinated paraffin, decabromodiphenvl, decabromodiphenylether, bisdibromopropylether-octachlorodiphenyl and, 2,4,6-trxbromophenozy-2,3-dibromopropane.

3. A composition according to Claim 2, wherein the chlorinated paraffin comprises 70% chlorine.

4. A composition according to Claim 1, 2 or 3, wherein the inorganic 03d.de is antimony oxide.

5. A composition according to Claim 1 substantially as described in any one of the foregoing Examples 1 to 5.

6. A lignocellulosic article comprising 16 to 40 parts by weight of a composition as claimed in any one of Claims 1 to 4 per 100 parts by weight of dry particles of lignocellulose.

7. A lignocellulosic article according to Claim 6 substantially as described in any one of the foregoing Examples 1 to 5.

8. A lignocellulosic article comprising two escternal layers and one or more internal layers, all of said layers comprising lignocellulose particles, wherein only one external layer incorporates or both external layers incorporate a fire-proofing composition as claimed in any one of Claims 1 to 5. 0706 - 13

9. ft multi-layered article according to Claim 8, wherein one external layer incorporates or both the external layers incorporate 16 to 40 parts by weight of the said fire-proofing composition per 100 parts by weight of dry 5 particles ox lignocsllulost·.

10. A multi-layered article ac^^rding to Claim 8 or 9, wherein the or each internal layer of the article is fireproofed by means of boric e.cid.

11. A multi-layered article according to Claim 10, 10 wherein the boric acid is present in a proportion of 5 to 20 parts by weight per 100 parte by weight of the dry lignocellulosic particles.

12. A multi-layered article according to Claim 8 substantially as described in any one of the foregoing

13. 15 Examples 1 to 4.