CS201714B1 - Thermoplastic vulkanizable mixture for manufacturing hydroinsulating roof foils - Google Patents

Description

The invention relates to a thermoplastic composition for the production of waterproofing roofing films.

So far, waterproofing and waterproofing coatings for roof coverings are mainly made of asphalt insulating strips. They are processed either by gluing into hot asphalt coatings or by melting with various types of melting equipment into asphalt substrates. Belts with different types of carrier liners can be used, which then affect the quality of the individual products. The disadvantages of these asphalted strips are limited workability at low temperatures (usable up to + 5 ° C), low ductility, considerable laborious laying. However, these belts have primarily low weather resistance, which results in loss of waterproofing function and short repair cycles.

Mixtures for the production of waterproofing films based on plastics and asphalt, such as films based on ethylene vinyl acetate copolymer asphalt, are known from the literature. Another example of the film-forming compositions may be those based on unvulcanized rubber, plastics and asphalt, or alternatively the rubber may be replaced by regenerated rubber according to U.S. Pat. No. 182416. These types of films can already be processed at temperatures below + 5 ° C, their disadvantage being low mechanical properties, especially at elevated temperatures and cold flux.

This problem is solved by the present invention, which is a thermoplastic vulcanized composition for the production of waterproofing films comprising fully vulcanized rubber. Preferably, so-called dynamic vulcanization can be used in the preparation of this mixture, the nature of which is to knead and vulcanize rubber and other additives in a kneading machine in the presence of a vulcanizing agent. Dynamic vulcanization is described in German Patents 2 202 706 and 2 202 738. The authors disclose here the partial dynamic vulcanization of an ethylene-propylene-diene terpolymer or an ethylene-propylene copolymer in the presence of polypropylene or polyethylene. The mixtures produced in this way are expensive due to the high polymer content and do not achieve good mechanical properties. Complete dynamic vulcanization of mixtures of ethylene propylene diene terpolymers and polypropylene or polyethylene, which results in a thermoplastic elastic mass, requires kneading on high-turn machines, such as a laboratory mixer with a working chamber content of 0.05 L.

On larger and more commonly used kneading machines where the speed is lower, it is not possible to produce these mixtures. On a Banbury-Bridge kneading machine at 30 rpm. irreversibly crosslinked products were obtained at the post-crush time. The dynamic vulcanization of such mixtures apparently requires greater shear forces at high rotor speeds. Such equipment on an industrial scale is not yet available.

The present invention, which is a thermoplastic vulcanized composition for the production of roof waterproofing sealable foils, characterized in that it contains 15 to 60% by weight of vulcanized ethylene-propylene terpolymer or unsaturated diene rubber or its copolymer, 15 to 60% by weight of asphalt 3 to 50% by weight of polyethylene or isotactic polypropylene and 10 to 50% by weight of reinforcing fillers.

Asphalt, which forms a suitable flux of polymer blends, is a decisive component in dynamic vulcanization in operational kneading machines. Isotactic polypropylene or polyethylene can be used as plastics. For economic reasons and also for the purpose of adjusting the properties, the mixtures can be filled, for example, with carbon black, kaolin, plasticizers or resins.

It is preferred that the rubber component of the composition comprises a mixture of ethylene propylene terpolymer and butadiene-styrene or natural rubber in a weight ratio of 1: 2 to 4: 1 and if the composition contains 1 to 10 weight percent of plasticizer.

Curing agents are introduced into the homogenized blend of polymers, asphalt, fillers and plasticizers at a temperature above 100 ° C. Depending on the type of vulcanization system, vulcanization takes place at different speeds in the kneading machine under the influence of shear forces. The vulcanization results in an increase in the power input of the drive unit of the kneading machine. The stirred mixture is discharged at a temperature of 190 to 220 ° C.

The hot mixture can be further processed on a heated double-roll into strips which are processed into granules or can be rolled directly into foils on multi-roll machines. An important fact in the production of these mixtures is the possibility of dynamic vulcanization on commercially available operating kneading machines, the obtained thermoplastic vulcanizate can be processed on rolling or extrusion machines. In the production of, for example, roof waterproofing membranes, the time-consuming vulcanization process is thus eliminated.

The presence of fully vulcanized rubber in the composition increases its ductility, tensile strength and elasticity, especially at elevated temperatures, eliminating the risk of cold flow of the composition. Depending on the content of fully vulcanized rubber, the mixtures are dimensionally stable up to 150 ° C. By a suitable combination of components, materials can be produced that can be compared qualitatively at normal or elevated temperatures with rubber materials produced by a conventional process, i.e. by vulcanizing the rubber mixture, for example in an autoclave or rotary press. Advantageously, materials having plastic-elastic behavior can be produced, which cannot be achieved with rubber waterproofing films.

The advantage of the films is their excellent resistance to weathering and ozone. The plastic-elastic behavior is important when sealing and shaping the roof details. Compared to rubber foils, they have higher pressure water resistance and: better structural strength. The films can be glued to the asphalt substrate by melting or laid in hot asphalt coatings, the joints can be welded by heat sources, while the bond strength is equal to the strength of the film itself.

Example 1

In a 60 L Banbury Bridge Bridge high pressure mixer, the thermoplastic composition of formula 1 was mixed. Rubber, zinc oxide, stearic acid, asphalt, polypropylene, carbon black and plasticizer were introduced into the kneader at an initial temperature of 25 ° C. After 2 minutes of kneading, the temperature at the control sensor reached 140 ° C, at which point vulcanizing agents were added while the water cooling was switched on. Within 2 minutes the power take-off of the drive unit was increased by 10%, after 10 minutes the sensor temperature reached 190 ° C, kneading was stopped and the chamber contents were drained. On a two-roll cylinder at a temperature of 160 ° C, 60 X 5 mm tapes were cut from the mixture and granulated after cooling. A 500 X 1.5 mm foil was extruded from the granulate on a 90 mm screw extruder at a die temperature of 190-200 ° C. Test specimens were punched from the film and mechanical properties determined.

Recipe used 1 parts by weight of ethylene-propylene terpolymer 100 polypropylene 133 asphalt 110 carbon black 50 naphthenic plasticizer 10 zinc oxide 5 stearic acid 1.5 tetramethylthiurammonosulfide 1.5

2-bis benzothiazolyl disulfide 0,5 sulfur 2 mechanical properties of film tensile strength elongation modulus 200% elasticity hardness ductility structural strength Crescent at 25 ° C frost-resistance NIlSP ozone-resistance

300 h, 25 ° C, 50% deformation

8,3 MPa

3,7 MPa 26%

Sh A 44%

35.4 N / mm —42 ° C 300 pphm unchanged

Example 2

mechanical values The mixing procedure is the same as that mass- in Example 1 parts tensile strength 1.8 MPa ductility 145% an ethylene-propylene terpolymer 70 elasticity 12% butadiene-styrene rubber 30 elongation 2Q% polyethylene 50 hardness 43ShA asphalt 50 soot 120 Mixture 2 mass- naphthenic plasticizer 30 parts zinc oxide 5 stearic acid 1 ethylene-vinyl acetate copolymer 100 ALIGN! tetramethylthiurammonosulfide 1.5 asphalt 50 mercaptobenzthiazole 0.7 soot 5 sulfur 2.5 antioxidant 0.4

mechanical properties foil tensile modulus elongation modulus 200% elasticity hardness structural strength Crescent at 25 ° C elongation frost - resistance NIIŠP ozone - resistance 300 pphm. 300 h 25 ° C, 50% deformation

8.5 MPa 432%

6.2 MPa 13%.

Sh A

N / mm 50% —33 ° C unchanged

Examples of thermoplastic compounds used for roof waterproofing membranes are as follows:

Mixture 1

Regenerated rubber mineral filler asphalt softens weight parts of mechanical value

tensile strength ductility elasticity elongation hardness 8,6 MPa 730% 23% 560% 84 Sh A Mixture ethylene-propylene rubber polyethylene asphalt soot chalk 100 ALIGN! 20 May 100 ALIGN! 100 ALIGN! 150 mechanical values tensile strength ductility elasticity elongation hardness 3.7 MPa 500% 25% 420% 69 Sh A

From the comparison, the improved properties of the compositions of the invention are evident.

Claims (4)

SUBJECT OF THE INVENTION Thermoplastic dynamically vulcanized composition for the production of waterproofing roofing foils, characterized in that it contains 15 to 60 weight percent of vulcanized ethylene propylene terpolymer or unsaturated diene rubber or copolymer thereof, 15 to 60 weight percent of asphalt, 3 to 50 weight percent of polyethylene or isotactic polypropylene and 10 to 50 weight percent of reinforcing fillers. 2. The thermoplastic composition of claim 1, wherein the rubber component is a mixture of ethylene-propylene terpolymer and butadiene-styrene rubber or natural rubber in a weight ratio of 1: 2 to 4: 1. 3. The thermoplastic composition of claim 1 comprising from about 1 to about 10 weight percent plasticizer. 4. The thermoplastic composition of claim 1, wherein the reinforcing filler is carbon black or active silica.