CZ33396U1 - Flame-retardant thermoplastic polyolefin mixture - Google Patents

Description

Technical field

The invention relates to a mixture based on thermoplastic polyolefins resistant to flame propagation. It is intended for the production of films for building applications where resistance of materials to flame propagation is required.

BACKGROUND OF THE INVENTION

Various materials, including plastic-based materials, can be used to provide the waterproofing function of flat and slightly sloping roofs. Commonly used materials are waterproofing films prepared from mixtures based on polyvinyl chloride (PVC). PVC waterproofing foils can be made in several versions, as single or multi-layer, homogeneous or heterogeneous, with a reinforcing polyester grid or with a glass fiber fleece. PVC waterproofing membranes are characterized by an excellent combination of features and price. Key features include, in particular, the rigidity and flexibility required for installation, weather resistance that ensures long service life, compliance with flame propagation resistance, the possibility of recycling both scrap and wastes from production / installation, and the use of end-of-life materials. In view of this, it is difficult to replace PVC with halogen-free and plasticizer-free alternative materials.

Non-halogen types of polyolefin waterproofing films appear on the market. Common types of polyolefins such as polyethylene (PE) and polypropylene (PP) are not suitable for this purpose. elastomers, PE or PP type. Thermoplastic polyolefins (TPOs), sometimes referred to as flexible polyolefins (FPOs) or thermoplastic elastomers (TPEs), are combined with other polymers, additives, and fillers to make the resulting blend functional in terms of processability, product properties and applicability, in combination with acceptable price. The starting TPO polymers used for roof waterproofing are always a mixture of hard and soft polymer segments (phases). The type of these hard and soft phases is critical to the ability of the final polymer to meet the technical requirements over a wide temperature range. Rubber or soft phases are important to achieve the good flexibility needed to install roofing sheets in cold weather. On the other hand, the soft phase does not contribute to the strength of the membrane and must therefore be supported by the solid phase of the polymer. It is the hard phase that defines and differentiates the end product. In general, it is problematic to provide non-flammability for polyolefin mixtures, which always results in the need to use a flame retardant in the mixtures. The choice and combination of feedstocks to meet the requirements for the final product applicable in the construction industry is the know-how of individual manufacturers of TPO / FPO / TPE waterproofing films.

The essence of the technical solution

The essence of the invention is that the flame-retardant thermoplastic polyolefin composition comprises 35 to 55 wt. parts of polypropylene-plastomer with a crystallinity of up to 20%, 10 to 20 wt. parts of a random polypropylene copolymer and 30 to 45 wt. parts of a flame retardant based on natural magnesium hydroxide.

The composition according to the invention may further preferably contain up to 8 wt. parts of a UV stabilizing concentrate (masterbatch), optionally 1 to 7 wt. parts of heat resistant paint concentrate (masterbatches).

The ratio of hard to soft phases in the mixture is preferably in the range of 0.30 to 0.45.

- 1 GB 33396 U1

The advantage of the flame retardant used is its natural nature, which in combination with polyolefinic types of polymers gives the mixture an environmental benefit compared to commonly used halogen polymer formulations and plasticizers.

The mixture according to the technical solution is suitable for the production of waterproofing roofing foils that meet the requirements of EN 13501-5 Fire classification of building products and building structures - Part 5: Classification according to the results of tests of roofs exposed to external fire, so-called BROOF test, class (tl) .

Examples of technical solutions

Example 1

The composition for the homogeneous film or for the upper layer of the multilayer film in the exemplary embodiment has the following composition:

Mixture component [masses, parts] PP plastomer (crystallinity up to 20%) 38 PP random copolymer 15 Dec Flame retardant based on natural magnesium hydroxide (brucite> 80%) 35 UV stabilizing concentrate (masterbatch) (stabilization against UV and thermal exposure during processing and application) 5 Masterbatch (with high thermal and weather stability for outdoor applications) 7 The ratio of hard and soft phases in the mixture 0.407

Example 2

In another variant of the exemplary embodiment, the composition has a composition for a homogeneous film, or for the upper layer of a multilayer film, it has the composition:

Mixture component [masses, parts] PP plastomer (crystallinity up to 20%) 46 PP random copolymer 10 Flame retardant based on natural magnesium hydroxide (brucite> 80%) 30 UV stabilizing concentrate (masterbatch) (stabilization against UV and thermal exposure during processing and application) 8 Masterbatch (with high thermal and weather stability for outdoor applications) 6 The ratio of hard and soft phases in the mixture 0.395

-2GB 33396 U1

Example 3

In the exemplary embodiment, the composition for the backsheet of the multilayer film has the following composition:

Mixture component [masses, parts] PP plastomer (crystallinity up to 20%) 46 PP random copolymer 18 Flame retardant based on natural magnesium hydroxide (brucite> 80%) 35 Masterbatch 1 The ratio of hard and soft phases in the mixture 0.398

Example 4

In another variation of the exemplary embodiment, the composition for the backsheet of the multilayer film has the composition:

Mixture component [masses, parts] PP plastomer (crystallinity up to 20%) 50 PP random copolymer 15 Dec Flame retardant based on natural magnesium hydroxide (brucite> 80%) 32 Masterbatch 3 The ratio of hard and soft phases in the mixture 0.318

Industrial applicability

It is possible to produce a film by extrusion or coextrusion from the proposed mixture based on thermoplastic polyolefins and a natural flame retardant. The film may be made as a single layer or a multilayer, while the final structures may also comprise reinforcing materials such as polyester grid, glass fleece or combinations thereof. The resulting material is particularly suitable for use in construction as a waterproofing roofing membrane.

Claims (4)

A composition based on thermoplastic polyolefins resistant to flame propagation, in particular for waterproofing films, characterized in that it contains 35 to 55 wt. parts of polypropylene of a plastomer with a crystallinity of up to 20%, 10 to 20 wt. parts of random polypropylene random copolymer and 30 to 45 wt. parts of a flame retardant based on natural magnesium hydroxide. The thermoplastic polyolefin composition according to claim 1, further comprising up to 8 wt. parts of UV stabilizing concentrate, masterbatch. The thermoplastic polyolefin composition of claim 1, further comprising 1 to 7 wt. parts of heat resistant color concentrate, masterbatch. The thermoplastic polyolefin composition according to claim 1, wherein the ratio of hard and soft phases in the composition is 0.30 to 0.45.