Latex-bound fireproofing material.

(42) Date of commencement of the patent: 15. 7.1990 (45) Date of issue: 25. 1.1991

<td>(56) Documents:</td><td>(73) Patent owner:</td>

<td>U.S. Patent 4,253,518 DE-0S3625080 JP-A-54-085249</td><td>CHEMIE LINZ SOCIETY MBH A-4021 LINZ, UPPER AUSTRIA (AT).</td>

<td></td><td>(72) Inventor:</td>

<td></td><td>HORACEK HEINRICH DR. LINZ, UPPER AUSTRIA (AT). WUDY HERMANN WELS, UPPER AUSTRIA (AT).</td>

(54) LATEX-CONTAINED FIRE-PROTECTION MATERIAL (57) Thermally expandable fire-protection compound consisting of expandable graphite, a carboxyl-containing, preferably aqueous chloroprene latex and substances which form a paracrystalline carbon skeleton in case of fire.

CQ

AT 392,078

Π® 0078818

AT 392 078 B

The invention relates to thermally expandable fire protection compounds or fire-resistant laminates containing expandable graphite, a chloroprene latex containing carboxyl groups and substances which form a paracrystalline carbon skeleton in the event of fire, and to a process for their preparation.

Thermally expandable fire protection materials which consist of expanded graphite, chloroprene rubber, a phenol resin, an organic solvent, and optionally additionally of aluminum hydroxide and inorganic fibers, are described for example in AT-PS 360,130. They prove to be particularly effective in preventive fire protection because of their excellent resistance to moisture, frost, heat, light and industrial climate, as well as due to their high inflation pressure. When exposed to heat and fire they expand in the event of fire in the opening to be protected with relatively low flowability. As a result, the expanding mass does not deviate from obstacles even in an incomplete orifice, and forms a tightly sealed barrier due to its high inflation or expansion pressure, which is usually greater than 2 bar, which reduces further propagation of heat, fire, and fumes or delayed or is completely prevented. This sealing material has a high mechanical strength even in the expanded state. However, a disadvantage of the production, processing and use of such compositions is their brittleness and low flexibility. Another disadvantage is that in their preparation organic solvents are used, the increased equipment complexity and increased work required for solvent recovery and to minimize any environmental pollution and health hazards caused by solvent.

The object of the invention was to eliminate these disadvantages occurring in the known fire protection compounds, and in particular to obtain less brittle masses, in the preparation of which no organic solvents are required. The object could be achieved by using a latex with a defined content of carboxyl groups for the fire protection compounds.

The present invention accordingly provides a thermally expandable fire protection composition, which comprises expanded graphite, a chloroprene latex having at least 0.3 moles of carboxyl groups per 1 kg of latex solids, in the event of fire a paracrystalline carbon skeleton-forming substances, and optionally further additives.

It proves to be particularly advantageous if the fire protection compositions contain no organic solvents, but if aqueous latex dispersions are used in the preparation. Due to the existing residual water content 'show these fire protection compounds a more favorable fire behavior than when using organic solvents. Because of the absence of organic solvents, they can be made much easier and much more environmentally friendly and processed. The fire protection compositions according to the invention are less brittle, so that plates or laminates produced therefrom are easier to handle because of their flexibility and, for example, can also be better wound into rolls.

The expanded graphite used can be prepared, for example, by acid treatment of a natural graphite with fuming nitric acid, as described in H. Spatzek, Carbon 86 (1986).

The chloroprene latex is usually prepared by copolymerization of chloroprene with acrylic acid or methacrylic acid. Such latices are for example as Skyprene ^ (Toyo soda), Bayprene ^ (Bayer), Butaclor ^ (Distugil), Denka Chloroprene ^ (Druki Kagaku Kogyo), Nairit ^ (USSR) or Neoprene ^ (Du Pont) in the trade.

The fire protection composition usually contains 25 to 60 wt.% Expanded graphite, 5 to 25 wt.%, Calculated as a solid, a chloroprene latex, Sustanzen that form a paracrystalline carbon skeleton in case of fire, and optionally additives.

Suitable substances which form a paracrystalline carbon skeleton in the event of fire are, for example, polyvinyl chloride (PVC), polyvinylidene chloride, polyacrylonitrile, cellulose or derivatives thereof, phenol-formaldehyde resins, polyfurfuryl alcohol or polyimides. When heated in the event of fire, these substances initially crosslink, wherein the strong intermolecular bonds are retained even during the further thermal stress, which leads to the pyrolytic decomposition and finally to the formation of the paracrystalline carbon skeleton. (Chemistry Ing.-Techn. 42 No. 9/10 (1970), p. 659-669). Three-dimensionally crosslinked thermosets, such as phenolic resins, prove to be particularly suitable.

Additives which modify the reaction to fire are, for example, melamine and its derivatives, various graphite salts, cyanuric acid derivatives, dicyandiamide, halogenated hydrocarbons, polyammonium phosphates and guanidine salts. These substances also inflate on exposure to heat with decomposition. Since they have a different decomposition temperature of expandable graphite, increases in case of fire with the rising temperature and the inflation pressure, whereby a firmer foreclosure of the opening takes place.

In addition, other additives that improve especially the strength of the sealant in the expanded state, solidify the crust and increase cohesion, such. B. inorganic fibers, for example mineral or glass fibers, glass powder, vermiculites, bentonites, silicic acid, silicates, borax, starch, sugars, chloiparaffins, aluminum sulfate, aluminum hydroxide or magnesium hydroxide. Furthermore, flame retardants may be added, for example halogenated or phosphorus-containing

-2AT392 078B

Hydrocarbons, such as. Tris-chloropropyl phosphate, dibromoneopentyl glycol, or antimony trioxide. Furthermore, such additives are also considered, which help to increase the foaming in the case of flame treatment. Such are, for example, salicylic acid, p-hydroxybenzoic acid, PVC, and nitrogen or sulfohydrazides, triazoles, urea dicarboxylic anhydride and ammonium carbonate

The fire protection composition of the invention can be used both as a paste, as well as in the form of plates, strips, tapes or Formkörpem. Fire protection laminates in which the fire protection compound is laminated onto a carrier web, for example a glass fiber fleece, are particularly advantageous and easy to use. For decorative reasons, or for example to protect the fire protection compound laminates or plates with a cover layer, such as a plastic sheet, for. B. a PVC film, paper or aluminum sheet, be covered on one or both sides. It is also possible to equip the fire-resistant laminates or boards with an adhesive layer, which is then advantageously covered with a release film.

The preparation of the fire protection compositions according to the invention is carried out by mixing and homogenizing expandable graphite, a carboxy-containing, voizugsweise aqueous latex dispersion, a fire in the event of a paracrystalline carbon skeleton-forming substance, eg. B. a phenol-formaldehyde resin or polyimide resin, and optionally further fire-behavior modifying additives, for example in a kneader, dissolver or mixer. The mass thus obtained can either be used as such, or it can be applied to a carrier web, for example to a film or a fleece (z. B. with the help of a squeegee) are applied. After drying, the laminate can be compressed on a calender, possibly with embossing roll, possibly with simultaneous lamination with a cover layer, for example made of PVC or aluminum.

The fire protection compositions according to the invention are used for fire protection sealing or Partitioning of openings in a fire compartment forming components, such. B. Joints between walls, hollow or Gaps, wall openings, cable glands or the like used. Similarly, door seals, window seals or other seals that foam in the event of fire and seal the upstream slot or opening can be made. The connection between the glass and the frame in fire-resistant glazings with the aid of the fire protection compounds or laminates according to the invention likewise results in optimum fire protection. The production of whole bricks is also possible, with which breakthroughs for cables or pipes are lined, and form a barrier when exposed to fire. In case of fire, these masses foam up due to the effects of heat and seal the opening, so that the further passage of fire and smoke and thus the further spread of the fire is prevented.

Examples 1 -15 and Comparative Example 16

The feedstocks listed in Tables 1 and 2 (in parts by weight) were added in the following order in a stirred tank: Additives, A1 (OH)₃, Phenolic resin, 50% aqueous Chloroprenlatexdispersion, expandable graphite, mineral fibers (Inorphil ^ 061-60, GM Langer, FRG). The mass was homogenized in each case for 1 hour by means of a dissolver with toothed disc at 30 ° C. and a pH of 10 (adjusted by means of KOH). The viscosity was about 4 Pas, measured at 30 ° C in the Brookfield viscometer (spindle 7, 20 rpm). The resulting fire protection composition was then applied to a glass fleece with a λ

Basis weight of 50 g / m aufgerakelt and dried at 190 ° C.

Commercially available latex dispersions based on a copolymer of chloroprene and methacrylic acid were used. The content of carboxyl groups given in Tables 1 and 2 was set by mixing the following latexes with different carboxyl groups: Neoprene ^ 115 (Du Pont): 0.33 mole COOH per 1 kg latex solids, neoprenes ^ 750 and neoprenes ^ 824A: no COOH content , Bayprene ^ 4R (Bayer): 0.23 moles of COOH per 1 kg of latex solids. In Comparative Example V 16, a 10% chloroprene solution in toluene was used under otherwise identical conditions in place of the aqueous latex dispersion

The properties of the fire-resistant laminates are also given in Tables 1 and 2. The inflation pressure was measured at 250 ° C on 113 mm diameter specimens sandwiched between two heatable metal plates. The pressure generated during inflation was transferred from the lower plate to a pressure transducer. The inflating material was not demarcated laterally and could spread unhindered in the plane. The swelling height was measured on samples with a diameter of 50 mm, which were inserted in a metal cylinder of 100 mm height and an inner diameter of 50 mm. The cylinder with the sample preloaded over a 100 g punch was heated in an oven at 300 ° C for 10 minutes.

-3AT392078B

Table 1 (starting materials in parts by weight)

<td>example</td><td>1</td><td>2</td><td>3</td><td>4</td><td>5</td><td>6</td><td>7</td><td>8th</td>

<td>Mole of carboxyl per 1 kg of latex solids</td><td>0.33</td><td>0.33</td><td>0.05</td><td>0.33</td><td>0.05</td><td>0.33</td><td>0.33</td><td>0.33</td>

<td>latex</td><td>21</td><td>30</td><td>30</td><td>27</td><td>21</td><td>27</td><td>27</td><td>27</td>

<td>phenolic resin</td><td>3</td><td>4</td><td>4</td><td>4</td><td>10</td><td>10</td><td>4</td><td>12</td>

<td>Inorphil ^)</td><td>-</td><td>2</td><td>2</td><td>-</td><td>2.1</td><td>-</td><td>-</td><td>-</td>

<td>expandable graphite</td><td>57</td><td>53</td><td>53</td><td>57</td><td>57</td><td>48</td><td>57</td><td>57</td>

<td>A1 (OH)₃</td><td>-</td><td>11</td><td>-</td><td>-</td><td>9.9</td><td>-</td><td>-</td><td>4</td>

<td>additives ^</td><td>19 / A</td><td>-</td><td>11 / B</td><td>12 / B</td><td>-</td><td>12 / B</td><td>12 / C</td><td>-</td>

<td colspan="9">characteristics</td>

<td>unexpanded¹</td><td>+</td><td>+</td><td>-</td><td>+</td><td>-</td><td>+</td><td>+</td><td>+</td>

<td>distended²</td><td>+</td><td>+</td><td>-</td><td>+</td><td>-</td><td>+</td><td>+</td><td>+</td>

<td>Thickness (mm)</td><td>2.4</td><td>2.5</td><td>2.8</td><td>2.5</td><td>2.5</td><td>2.4</td><td>2.6</td><td>2.2</td>

<td>grammage</td><td>2.56</td><td>2.02</td><td>2.16</td><td>2.50</td><td>2.50</td><td>2.43</td><td>2.47</td><td>2.05</td>

<td>(Kg / m²) Inflation pressure (bar)</td><td>12.5</td><td>6.8</td><td>7</td><td>8th</td><td>6</td><td>8.5</td><td>9.6</td><td>8.7</td>

<td>Blowing height (mm)</td><td>19</td><td>17</td><td>20</td><td>20</td><td>13</td><td>15</td><td>13</td><td>17</td>

<td>¹ + flexible, - brittle 9 + stable, - unstable 3 A aluminum sulphate B dicyandiamide C melamine</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td colspan="9">Table 2 (Starting materials in parts by weight)</td>

<td>example</td><td>9</td><td>10</td><td>11</td><td>12</td><td>13</td><td>14</td><td>15</td><td>V16</td>

<td>Moles of carboxyl per 1 kg Latex solid</td><td>0.33</td><td>0.17</td><td>0</td><td>0.23</td><td>0.33</td><td>0.33</td><td>0.23</td><td>0</td>

<td>latex</td><td>27</td><td>27</td><td>27</td><td>27</td><td>25</td><td>40</td><td>22</td><td>55 (toluene)</td>

<td>phenolic resin</td><td>4</td><td>4</td><td>4</td><td>4</td><td>6</td><td>7</td><td>6.5</td><td>5</td>

<td>Inorphil ^</td><td>-</td><td>-</td><td></td><td>-</td><td>1.4</td><td></td><td>1.5</td><td>1.3</td>

<td>expandable graphite</td><td>57</td><td>57</td><td>57</td><td>57</td><td>54.6</td><td>37</td><td>42</td><td>29.3</td>

<td>A1 (OH)₃</td><td>-</td><td>-</td><td>-</td><td>-</td><td>13</td><td>5</td><td>14</td><td>9.4</td>

<td>additives ^</td><td>12 / D</td><td>12 / E</td><td>12 / F</td><td>12 / G</td><td>-</td><td>11 / H</td><td>14 / H</td><td>-</td>

<td colspan="9">characteristics</td>

<td>unexpanded¹</td><td>+</td><td>-</td><td>-</td><td>-</td><td>+</td><td>+</td><td>-</td><td>+/-</td>

<td>distended²</td><td>+</td><td>-</td><td>-</td><td>-</td><td>+</td><td>+</td><td>-</td><td>+</td>

<td>Thickness (mm)</td><td>2.3</td><td>2.5</td><td>2.2</td><td>2.2</td><td>2.5</td><td>2.6</td><td>2.5</td><td>2.5</td>

<td>grammage</td><td>2.79</td><td>3.53</td><td>2.47</td><td>1.84</td><td>3.6</td><td>2.8</td><td>3.0</td><td>2.5</td>

<td>(Kg / m²) Inflation pressure (bar)</td><td>12</td><td>13</td><td>8.6</td><td>8.8</td><td>13</td><td>10</td><td>8th</td><td>3</td>

<td>Blowing height (mm)</td><td>12</td><td>19</td><td>13</td><td>17.5</td><td>19</td><td>17</td><td>12</td><td>18</td>

-4AT392078B + flexible, - brittle, +/- less flexible + stable, - unstable ³ D strength E Borax

F guanylurea sulfate G guanidine phosphate H guanidine carbonate

Example 17:

Small firing test with laminates according to Example 13 and V16

In order to detect the effective in case of fire sealing an opening with the fire protection composition according to the invention, two 20 cm long PVC pipes with an outer diameter of 16 cm and a wall thickness of 3.5 mm, each 230 g of a 15 cm wide fire protection laminate according to Example 13, the Fleece side was additionally laminated with a 0.05 mm thick aluminum foil, wrapped, with the expanded graphite tube side came to rest. The wrapped tubes were each packed in a zinc plate cuff and inserted into each one bore (22 cm diameter) of a 10 cm thick lightweight concrete slab (Ytong ^ ü). The tubes protruded 5 cm from the bore on both sides of the plate.

In two further, similar holes in the lightweight concrete slab two tubes wrapped in an analogous manner were inserted, but instead of the fire protection laminate according to the invention, a fire protection laminate according to Comparative Example V 16 was used. The somewhat less flexible laminate showed small cracks and slight breakages during winding.

Subsequently, the lightweight concrete slab was installed on the basis of DIN 4102 in a small fire chamber, and according to the uniform temperature curve from one side to a temperature of about 1000 ° C flames. The fire protection compounds started by the heat after approx. 4 To inflate minutes, with all 4 PVC pipes softened and compressed. The foreclosures with the laminates according to Example 13 were after 13 or 14 Minutes, those with the laminates according to Comparative Example V 16 to 13 or 17 Minutes completely closed, so that no flue gases, fire or soot penetrated more outward. After 40 minutes, the outwardly projecting pipe stumps of the foreclosure according to the invention began to break apart, while the pipe stumps of the foreclosures according to the comparative example began to melt. After 60 minutes, the pipe stumps were completely broken off or melted, the temperature of the expanding foam according to Example 13 was 290 ° C, that of the expanding foam according to Comparative Example V16 at 310 or 370 ° C.

After 80 minutes, the experiment was stopped without flame or flue gas breakthroughs were detectable. It was also found that when using the fire protection composition according to Example 13 on the side facing away from the fire in the course of the fire test a 20- 80 ° C lower temperature prevailed than when using the conventional fire protection composition according to Comparative Example V 16th