IE43388B1 - A covering material and a process for the manufacture thereof - Google Patents

Abstract

1512357 Bitumen-coated fabric SOPREMA ET USINES ALSACIENNES D'EMULSIONS REUNIES S AR'L 14 June 1976 [30 June 1975] 24505/76 Heading B2E A covering material is obtained by impregnating a web of bonded un-woven polyester fibres with bitumen by passing the web over coating rollers dipping into molten bitumen at between 160‹C and 180‹C, coating the whole of one surface or both surfaces of the impregnated web with a coating mixture at between 180‹C and 200‹C, the mixture being obtained by stirring bitumen in a mixer without causing the bitumen to include air bubbles and mixing into this bitumen a pulverulent polymer and a thermoplastic resin and covering the coated surface or surfaces with an anti-adhesion substance. The anti-adhesion substance may be sand or talc powder, flakes of slate, or coloured granules. The pulverulent polymer may be an elastomer of the copolymer block polystyrene-polybutadiene-polystyrene type and the thermoplastic resin may be of the polydiene hydrocarbon resin type or the polycyclic thermoplastic hydrocarbon resin type.

Description

This invention relates to a covering material and a process for the manufacture thereof, the material being of the kind comprising a non-woven web impregnated with bitumen and covered with sand or other anti-adhesion substances.

Some known materials of the kind referred to have disadvantages, for example lack of tensile strength, liability to crack when bent at normal atmospheric temperatures, very high weight per square metre, high cost, or little resistance to penetration by loads pressing on small areas.

The present invention is intended to provide a process and a material of the kind referred to such that at least some of the indicated disadvantages may be mitigated.

According to the invention there is employed a process for the manufacture of a covering material comprising the following steps:i) causing a web of bonded unwoven polyester fibres to become impregnated with bitumen by passing the web over coating rollers which dip into bath af the molten bitumen at a temperature between 160° and 180°C, ii) coating the whole of one surface or of both surfaces of the impregnated web with coating mixture at a temperature between 180° and 200°C, - 2 43388 the coating mixture being obtained by stirring bitumen in a mixer without causing the bitumen to include air bubbles and mixing into this bitumen a pulverulent polymer and thermoplastic resin, iii) covering the coated surface or surfaces with anti-adhesion substance.

A preferred material when made by the process of the invention is characterised in that: i) the web has the following characteristics:weight between 125 and 500 grammes per square metre, softening point 230° to 250°C, melting point 255°C, water absorption below 0.4’i, fibres bonded by 7% of acrylic binder, rupture resistance to 180 N/cm, in the longitudinal direction and 30 N/cm in the transverse direction, rupture elongation 30K in the longitudinal direction and 40K in the transverse direction, dimensional variation below 12 when raised to a temperature of 18O°C.; ii) the bitumen for impregnating the web has the following characteristics:ball-and-ring softening point between 40° and 50°C, penetration at 25°C between 80 and 100, result below 0.3 mm. for the Oliensis test; iii) the coating mixture comprises direct distillation bitumen with the characteristics of ball-and-ring softening point between 40 and 50°C and penetration at 25°C between 80 and 100, and pulverulent polymer consisting of elastomer of the copolymer block polystyrene-polybutadiene-polystyrene type, and thermoplastic resin of the polydiene hydrocarbon resin type with ball-and-ring softening point between 70 and 125°C and of mean molecular weight - 3 43388 between 1000 and 1300, or of the polycyclic thermoplastic hydrocarbon resin type based on reactive polydiene having a mean insaturation the ball-and-ring softening point of which is between 80 and 115°C, and with molecular weight between 600 and 700.

Hot/ the invention may be put into practice appears from the following Examples.

EXAMPLE I.

Commencing with a web consisting of unwoven polyester fibres bonded together by acrylic binder, and having a weight between 125 and 500 g/sq.m., a covering material is made by the steps of:i) causing the web of bonded unwoven polyester fibres to become impregnated with bitumen by passing the web over coating rollers which dip into a bath of the molten bitumen at a temperature between 160° and 180°C; ii) coating the whole of one surface or of both surfaces of the impregnated web with coating mixture at a temperature between 180° and 200°C, the coating mixture being obtained by stirring bitumen in a mixter without causing the bitumen to include air bubbles and mixing into this bitumen a pulverulent polymer and a thermoplastic resin; iii) covering the coated surface or surfaces with anti-adhesion substance.

EXAMPLE II.

A covering material is made as set forth in Example I, the bitumen selected for the impregnation having a ball-and-ring softening point between 40 and 50°C, a penetration at 25°C between 80 and 100, and giving a result below 0.3 mm. to the Oliensis test relating to exudation phenomena. The web is kept in contact with the molten bitumen only for the time necessary for total saturation, the coating rollers being just covered each with a fine bitumen film. The impregnation rate after non-heating drying of the impregnated web is between 230% and 270%. - 4 43388 EXAMPLE III.

Proceeding as in Example I or II, the preparation of the coating mixture includes mixing a bitumen having a ball-and-ring softening point between 40 and 50°C and a penetration between 80 and 100, in a mixer with an agitator so that the mixing is effective but avoids undue heating or occlusion of air or gas in the bitumen, which is kept at a temperature between 180 and 200°C. There is then introduced into the mixer in the form of fine powder an elastomer the particle size of which is between 200/* and 800/* , in the proportion of 3% to 15%, preferably 6% to 9%, by weight in relation to the bitumen. This mixing of bitumen and elastomer is continued for at least 45 minutes, preferably for an hour. In the course of the mixing of the bitumen and elastomer there is added a thermoplastic resin, for example of the polydiene hydrocarbon resin type, with ball-and-ring softening point between 70° and 125°C, preferably 110° to 120°C, and mean molecular weight between 1000 and 1300. The quantity of resin added is between 2% and 5%, preferably 3%, by weight in relation to the bitumen.

EXAMPLE IV.

The procedure is as in Example III, except that instead of the polydiene resin there is used a polycyclic thermoplastic hydrocarbon resin type based upon reactive polydiene, having a mean insaturation, the ball-andring softening point of which is between 80 and 115°C, preferably 100 to. 11O°C, and of molecular weight between 600 and 700.

EXAMPLE V.

The procedure is as in Example III and IV and to the mixture in the mixer there are added fillers of limestone powder or fly ash or slate powder or other mineral powder, the particle size of which is below 80/* , the quantity of fillers being between 10% and 50% and preferably 40% by weight in relation to the complete mixture. - 5 4338 8 EXAMPLE VI.

The procedure is as in Example V and the coating mixture is then introduced into one ormore surfacing vessels, the impregnated web is then passed over a roller dipping into this coating mixture and coating the lower surface of the impregnated web. At the same time coating mixture is poured onto the upper surface of the impregnated web. According to the regulation of these two operations the thicknesses of the coatings on the two surfaces can be equal or different.

The total thickness of the impregnated and coated web is then regulated by passage through fixed or mobile calenders the space between the rollers of which is regulated according to the desired thickness.

EXAMPLE VII.

The procedure is as in Example VI, the anti-adhesion substance comprising sand or talc powder or coloured granules or mineral flakes or metallic foil or film of synthetic material.

EXAMPLE VIII.

The procedure is as in Example VII, the web being selected so that it owes its strength primarily to the physical bonds existing between the fibres and requires less than 10% of acrylic binder, and the web has the following characteristics:Weight between 1250 and 500 grammes, preferably 350 grammes, per square metre, Temperature resistance: Softening point 230 to 250°C, melting point 255°C, resistance to rotting, resistance to ageing, resistance to corrosion, dimensional stability, water absorption below 0.4%, high rupture resistance due to the length of the fibres.

EXAMPLE IX.

The procedure is as in Example VIII, the web being selected so as to produce the following test results:- Tests Longitudinal direction Transverse direction Rupture resistance N/cm. 180 90 Load at 5% elongation in N/cm. 70 30 Rupture elongation % 30 40 elasticity: about 6%, water vapour permeability, dimensional stability under varying conditions of temperature and humidity, for example variation below 1% for a temperature of 180°C.

EXAMPLE X.

The procedure is as in any one of Examples I to IX, the polymer being a thermoplastic polymer of the copolymer block polystyrene-polybutadienepolystyrene type, and the coating mixture possessing the following characteristics:ball-and-ring softening point higher than 100°C, penetration at 25°C: from 25 to 35 tenths of a millimetre, no cracking on cold folding down to -10°C, elasticity with 100% elastic return, superior to 2000%, and the final composition of the coating mixture being:by weight 80/100 bitumen 50% limestone filler 40% block copolymer 7% resin 3% - 7 4 3 3 8 8 By selection of materials and substances and proceeding as set forth in any one of the Examples it is possible to produce a covering material which possesses the following composition:kg./sq.m.

Web of unwoven bonded polyester fibres 0.350 Impregnating bitumen 0.875 Filled coating mixture 3.575 Surfacing of sand 0.200 Total weight 5 Alternatively there may be produced a covering material with slated auto-protection and possessing the following composition: kg,/sq.m.

Web of unwoven bonded polyester fibres 0.350 Impregnating bitumen 0.875 Filled coating mixture 3.575 Sand 0.100 Slate flakes 0.800 Total weight 5 Such a covering may be used, for example in sealing flat roofs, sealing in car parks under bituminous-coated stone chips, sealing in tunnels, or sealing in ponds or weirs.

It is possible to incorporate a fungicidal agent in the coating · mixture and to utilise the covering material as sealing in flat roof gardens to resist the penetration of roots.

Claims (11)

1. A process for the manufacture of a covering material comprising the following steps:i) causing a web of bonded unwoveh polyester fibres to become impregnated with bitumen by passing the web over coating rollers which dip into a bath of the molten bitumen at a temperature between 160° and 180°C; ii) coating the whole of one surface or of both surfaces of the impregnated web with coating mixture at a temperature between 180° and 200°C, the coating mixture being obtained by stirring bitumen in a mixer without causing the bitumen to include air bubbles and mixing into this bitumen a pulverulent polymer and a thermoplastic resin; iii) covering the coated surface or surfaces with anti-adhesion substance.

2. A process according to Claim 1, wherein the anti-adhesion substance comprises sand or talc powder or other fine mineral material, or flakes of slate or coloured granules, or metal foil.

3. A process according to Claim 1 or 2, comprising the step of filling the coating mixture with pulverulent mineral fillers.

4. A process according to Claim 3 wherein the fillers comprise limestone powder or fly ash or slate powder.

5. A covering material when made by a process according to any one of Claims 1 to 4, characterised in that i) the web has the following characteristics:weight between 125 and 500 grammes per square metre, softening point 230° to 250°C, melting point 255°C, water absorption below 0.4%, fibres bonded by 7% of acrylic binder, rupture resistance 180 N/cm. in the longitudinal direction and 30 N/cm.in the transverse direction, - 9 4 3 3 8 8 rupture elongation 302 in the longitudinal direction and 402 in the transverse direction, dimensional variation below 12 when raised to a temperature of 180°C; ii) the bitumen for impregnating the web has the following characteristics:ball-and-ring softening point between 40° and 50°C, penetration at 25°C between 80 and 100, result below 0.3 mm. for the Oliensis test; iii) the coating mixture comprises direct distillation bitumen with the characteristics of ball-and-ring softening point between 40 and 50°C and penetration at 25°C between 80 and 100, and pulverulent polymer consisting of elastomer of the copolymer block polystyrene-polybutadiene-polystyrene type and thermoplastic resin of the polydiene hydrocarbon resin type with ball-andring softening point between 70 and 125° and of mean molecular weight between 1000 and 1300, or of the polycyclic thermoplastic hydrocarbon resin type based on reactive polydiene having a mean insaturation the ball-and-ring softening point of which is between 80 and 115°C, and with molecular weight between 600 and 700.

6. A covering material according to Claim 3, wherein the coating mixture has the following characteristics:ball-and-ring softening point above 100°C, penetration at 25°C: 25 to 35 tenths of a millimetre, no cracking on cold folding down to -10°C, elasticity with 1002 elastic return higher than 2002.

7. A material according to Claim 5 or 6, wherein the coating mixture comprises by weight:80/100 bitumen 502 limestone filler 402 - 10 43388 block copolymer 7% resin 3%

8. A covering according to Claim 5, 6 or 7 wherein the final composition is as follows:kg/sq.ni.... web 0.350 impregnating bitumen 0.875 filled coating mixture 3.575 pulverulent mineral anti-adhesion material 0.200

9. A covering material according to Claim 6 or 7 wherein the final composition is: kg/sq.ni. web of unwoven polyester fibres 0.350 impregnating bitumen 0.875 filled coating mixture 3.575 sand 0.100 slate flakes 0.800

10. A process according to Claim 1 and as set forth in any one of Examples II to X.

11. A covering material when made by a process according to Claim 10.