WO2013190069A1

WO2013190069A1 - Foams containing butene and ethylene

Info

Publication number: WO2013190069A1
Application number: PCT/EP2013/062946
Authority: WO
Inventors: Jean-Pierre Mayeres; Denis Job; Rafaël Zamorano
Original assignee: Nmc Sa
Priority date: 2012-06-21
Filing date: 2013-06-20
Publication date: 2013-12-27
Also published as: BE1020760A3; EP2864403A1

Abstract

The present invention relates to foams containing butene and ethylene and more particularly foams containing 1-butene and ethylene. Foams containing butene and ethylene which comprise at least one polymer which contains ethylene and is rich in ethylene and also at least one polymer which contains butene and is rich in 1-butene, the melting point of the latter being below 135°C.

Description

Foams based on butene and ^ethylene

The present invention relates to butene-based foams and ^ethylene and more particularly 1-butene-based foams and ^ethylene.

Polyethylene foams and LLDPE (Jinear low-density polyethylene

copolymer based on ^ethylene and ^a α-olefin) were already described, for example in the document EP1373401.

The LLDPE used, however, is a copolymer which is very rich in ethylene and poor in oolefin. The foams obtained thus have the characteristics of foams based on polyethylene. These foams consequently have, for example, relatively good insulating properties, but flexibility or flexibility that is too low for certain applications.

On ^the other hand, based foams ^of a blend of polyethylene ^and a polymer based on ^a ooléfine ^or a copolymer of ^ethylene and ^a ooléfine are also disclosed in DE102009028200.

These foams can be richer in oolefin and especially in polybutene-1.

However, when ^one uses a mixture of polyethylene and polybutene-1 or a mixture of polyethylene and ^a copolymer of ^ethylene and butene-1, rich in butene-1 is obtained foams having the mechanical strength is bad. In this respect, it is known that polybutene-1 and polyethylene are not compatible. They form distinct phases (phase separation).

Indeed, this incompatibility is even put to use because of the films ^of a mixture of polybutene-1 and polyethylene are used as the movies "easy peel" (easy peeling). These films are used for example in the field ^of packaging to allow easy opening.On stress the film cracks and splits quickly.

These films, which have nodules of polybutene or a butene-rich dispersed phase (s) in a phase of polyethylene or ethylene-rich, are weakened, because ^the interface between polyethylene and polybutene is fragile. In such ^a film, the cracks easily propagate between and / or especially at the interfaces between the nodules of polybutene or ^a butene-rich dispersed phase (s) and the polyethylene or the ethylene-rich phase. The ^{incompatibility} between polyethylene and polybutene-1 therefore leads accordingly to poor mechanical properties.

However for some applications, it would be interesting to have ^a very flexible foam and still having good mechanical properties. This is possible due to the butene based foams and ^ethylene according to the present invention and according to independent claim 1. In addition, the present invention also relates to a foaming process for ^obtaining the butene based foams and ^ethylene according to the present invention and according to independent claim 12.

^Other embodiments of the foams and the foaming process of the present invention are described in the dependent claims.

The present invention relates to butene-based foams and ^ethylene which comprise at least one polymer based ^on ethylene and ethylene-rich and ^that at least one polymer based on butene-rich butene-1, the temperature melting thereof being less than 135 ° C. This allows to ^obtain very flexible foams and having good mechanical properties.

Indeed, ^the use / ^the addition ^of a polymer based on butene and rich in butene-1 makes it possible ^to greatly increase the flexibility / flexible foams obtained. Moreover, this also makes it possible to maintain excellent flexibility / flexibility of the foams obtained over a wide temperature range. In particular, this ^ensures good flexibility / high-temperature flexibility (eg above 40 ° C) and / or low temperature (eg below 20 ° C).

On ^the other hand, the fact to ^use at least one polymer based on butene-rich polybutene-1, whose melting temperature is lower than 135 ° C, makes it possible, surprisingly, to ^obtain foams with ^excellent mechanical properties. In addition, the polyethylene component ^achieves good properties in terms of ^heat insulation. Furthermore, ^the use / ^the addition ^of a polymer based on butene-rich butene-1 makes it possible optionally ^to further improve these properties ^of thermal insulation.

A polymer based on ^ethylene and ethylene-rich may be for example at least one homopolymer or at least one copolymer of ^ethylene. A polymer based on ^ethylene and ethylene-rich may be for example at least one polymer selected from the following group: polyethylene very low density (PE-TBD / VLDPE), linear low density polyethylene (LLDPE / LLDPE), low density polyethylene (PE-BD / LDPE), polyethylene medium density (PE-MD / MDPE), high density polyethylene (PE-HD / HDPE), very low molecular weight polyethylene (ULMWPE), high molecular weight polyethylene (HMWPE).

A polymer based on ^ethylene can be for example at least one copolymer, at least one block copolymer, at least one gradient copolymer, at least one random copolymer, at least one graft copolymer, at least one interpolymer or at least a copolymer which represents a combination of several of these types of copolymers. A copolymer is a polymer which comprises at least two different monomers.

A foam based on butene and ^ethylene according to the present invention may comprise at least a polymer based on ^ethylene and ethylene-rich, which may preferably include, for example at least 50%, preferably at least 51%, of preferably at least 55%, preferably at least 60%, preferably at least 70%, preferably at least 75%, preferably at least 80%, preferably at least 85%, preferably at least 90%, preferably at least 95%, preferably at least 97%, preferably at least 98% or at least 99% by weight of ^ethylene. Rich in ethylene may therefore mean for example comprising at least 50%, preferably at least 51%, preferably at least 55%, preferably at least 60%, preferably at least 70%, preferably at least 75%, preferably at least 80%, preferably at least 85%, preferably at least 90%, preferably at least 95%, preferably at least 97%, preferably at least 98% or at least 99% by mass ^of ethylene. This allows for example to ^obtain foams having such good properties ^of thermal insulation.

A foam according to the present invention may in one embodiment for example comprise low density polyethylene (PE-BD / LDPE) as ^an ethylene-rich and ethylene-rich polymer. The low density polyethylene may be obtained for example by radical polymerization of ^ethylene. The rate of connection of low density polyethylene is higher than the rate of connection of high density polyethylene (PE-HD / HDPE). The low density polyethylene may for example have a density ^of around 0.91 to 0.935 g / cm ^3.

A foam based on butene and ^ethylene according to the present invention may comprise at least a polymer based on ^ethylene and ethylene-rich, the melting temperature determined by DSC can for example be between 30 ° C and 160 ° C, preferably between 40 ° and 155 ° C, preferably between 45 ° C and 150 ° C, preferably between 60 ° C and 147 ° C, preferably between 70 ° C and 146 ° C, preferably between 80 ° C C and 145 ° C, preferably between 85 ° C and 144 ° C, preferably between 90 ° C and 143 ° C, preferably between 95 ° C and 140 ° C ° C, preferably between 100 ° C and 135 ° C, preferably between 102.5 ° C and 132.5 ° C, preferably between 105 ° C and 130 ° C, preferably between 105 ° C and 1 15 ° C or between 120 ° C and 130 ° C.

The melting temperature ^of a polymer based on ^ethylene and ethylene-rich determined by DSC can for example in the case of low density polyethylene (LDPE / LDPE) be between 90 ° C and 120 ° C, preferably between 105 ° C and 1 18 ° C, preferably between 105.5 ° C and 1 17.5 ° C, preferably between 106 ° C and 1 17 ° C, preferably between 107 ° C and 1 15 ° C, preferably between 107.5 ° C and 1 14.5 ° C, preferably between 1 10 ° C and 1 14.25 ° C, preferably between 1 1 1 ° C and 1 14 ° C. The melting temperature ^of a polymer based on ^ethylene and ethylene-rich, as determined by DSC can for example in the case of high density polyethylene (HDPE / HDPE) be between 1 15 ° C and 135 ° C preferably between 120 ° C and 130 ° C, preferably between 122.5 ° C and 127.5 ° C.

A foam based on butene and ^ethylene according to the present invention may comprise at least a polymer based on ^ethylene and ethylene-rich, which may have a melt index (melt flow index or melt flow rate) for example measured 190 ° C. with a standard mass of 2.16 kg (ISO standard 1,133), which can be for example between 0.1 and 35 g / 10 min, preferably between 0.15 and 30 g / 10 min, of preferably between 0.2 and 25 g / 10 min, preferably between 0.225 and 12 g / 10 min, preferably between 0.25 and 8 g / 10 min, preferably between 0.3 and 5 g / 10 min, of preferably between 0.325 and 4 g / 10 min, preferably between 0.35 and 0.8 g / 10 min, preferably between 0.6 and 0.7 g / 10 min.

A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene and butene-rich, which may preferably include, for example at least 25%, preferably at least 30%, preferably at least 35%, preferably at least 40%, preferably at least 45%, preferably at least 50%, preferably at least 55%, preferably at least 60%, preferably at least 65%, preferably at least 50%; at least 70%, preferably at least 75%, preferably at least 80%, preferably at least 85%, preferably at least 90%, preferably at least 95%, preferably at least 97%, preferably at least 98% or at least 99% by weight of butene-1. However, the butene-1 rich can preferably be used, for example, to comprise at least 50%, preferably at least 51%, preferably at least 55%, preferably at least 60%, preferably at least 70%, preferably at least 70%. minus 75%, preferably at least 80%, preferably at least 85%, preferably at least 90%, preferably at least 95%, preferably at least 97%, preferably at least 98% or at least 99% by weight of butene-1. This allows for example to ^obtain foams having flexibility / flexibility.

A butene-based polymer and / or a butene-based polymer rich in butene-1 may be, for example, a polymer comprising butene-1, 2-butene-2, E-butene-2 and / or or 2-methylpropene.

A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene-rich butene-1, which may preferably include, for example at least 50%, preferably at least 51%, preferably at least 55%, preferably at least 60%, preferably at least 65%, preferably at least 70%, preferably at least 75%, preferably at least 80%, preferably at least 85%, preferably preferably at least 90%, preferably at least 95%, preferably at least 97%, preferably at least 98%, preferably at least 99%, preferably at least 99.5%, preferably at least 99.9%, preferably at least 99%; at least 99.99%, preferably at least 99.999% by weight of butene-1. This allows to ^obtain foams having flexibility / flexibility. Furthermore, a polymer based on butene-rich butene-1 optionally also allows to ^improve tolerance additives (fillers) and / or the properties ^of thermal insulation.

A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene-rich butene-1, which is preferably for example, have a melt index (melt flow index or melt flow rate ) for example, measured at 190 ° C. with a standard mass of 2.16 kg (ISO standard 1,133), which may for example be between 0.3 and 2 g / 10 min, preferably between 0.325 and 1.5 g. / 10 min, preferably between 0.35 and 1 g / 10 min, preferably between 0.45 and 0.95 g / 10, preferably between 0.4 and 0.6 g / 10 min or between 0.7 and 0.9 g / 10min. A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene-rich butene-1, which may for example be a copolymer, a block copolymer, a gradient copolymer, random copolymer, a graft copolymer, an interpolymer or a copolymer, which represents a combination of several of these types of copolymers. A copolymer may be a polymer that comprises at least two different monomers. ^The addition ^of a second and / ^or another monomer and ^the use ^of a copolymer used to modify and / or ^adapt the melting temperature ^of a polymer based on butene easily. In addition, the structure / nature of the copolymer can also influence the melting temperature. This allows for example to reduce the melting temperature and / or to ^obtain a melting temperature e.g. less than 135 ° C while retaining the properties (and particularly the great flexibility / flexibility) of polybutene-1.

A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene, which can be for example a copolymer comprising 1-butene and at least one other ooléfine. A polymer based on butene may be for example a copolymer comprising 1-butene and ^ethylene and / or propylene.

^The use polymer based on butene, which is a copolymer comprising 1-butene and at least one other ooléfine, reduces the polymer melting temperature based on butene. Indeed, ^the incorporation ^of at least one other ooléfine, such as ^ethylene and / or propylene, in a copolymer comprising 1-butene and at least one other ooléfine may optionally allow for example to reduce the temperature of melting of the copolymer for example with respect to polybutene-1.

The ^{incorporation} / I addition ^{^of} at least one other ooléfine, such as ^ethylene and / or propylene, a polymer based on butene to obtain a copolymer comprising 1-butene and at least one other ooléfine , may indeed possibly disturb the crystallization of polybutene-1 and the formation of corresponding crystalline domains. This may, for example, lead to a decrease in the melting temperature of the polymer / copolymer, for example. In addition, the melting temperature ^of a copolymer rich in butene-1 copolymer comprising butene-1 and at least one other ooléfine may preferably e.g. decrease when the content ooléfine (e.g., ethylene and / or propylene) increases. This allows for example to reduce the melting temperature and / or to ^obtain a melting temperature for example below 135 ° C while maintaining the properties (particularly the flexibility / flexibility) of polybutene-1.

A butene-based polymer rich in butene-1 may, for example, be a copolymer comprising two monomers. A polymer based on butene-rich butene-1 can thus for example be a copolymer comprising 1-butene and ^ethylene or propylene. Preferably a polymer based on butene-rich butene-1 may be for example a copolymer comprising 1-butene and ^ethylene. This eventually ^prevents alterations in properties due to the presence ^of one or more types of additional monomers.

A polymer based on butene-rich butene-1 can preferably for example comprise only a few units ^of another monomer. A butene-based polymer rich in butene-1 may, for example, comprise between 0.001% and 10%, preferably between 0.1% and 9%, preferably between 0.2% and 8%, preferably between 0.3% and 7%, preferably between 0.4% and 6%, preferably between 0.5% and 5.5%, preferably between 0.7% and 5%, preferably between 0.9% and and 4.5%, preferably between 1% and 4% ^of a other monomer, for example, another α-olefin such as ^ethylene or propylene. This allows for example to reduce the melting temperature and / or to ^obtain a melting temperature for example below 135 ° C while maintaining the properties (particularly the flexibility / flexibility) of polybutene-1. A polymer based on butene-rich butene-1 may preferably comprise for example not mean ^that approximately 100, 50, 25, 10 or 3 units ^of another monomer. This also allows for example to reduce the melting temperature and / or to ^obtain a melting temperature for example below 135 ° C while maintaining the properties (particularly the flexibility / flexibility of the polybutene-1). A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene and / or a polymer based on butene-rich butene-1, the determined by DSC melting point may be for example less than 135 ° C, preferably less than 134 ° C, preferably less than 133 ° C, preferably less than 132 ° C, preferably less than 131 ° C, preferably less than 130 ° C, preferably less than 129.5 ° C, preferably less than 129 ° C, preferably less than 128.5 ° C, preferably less than 128 ° C, preferably less than 127.5 ° C, preferably less than 127 ° C C, preferably less than 126.5 ° C, preferably less than 126 ° C, preferably less than 125.5 ° C, preferably less than 125 ° C, preferably less than 124.5 ° C, preferably less than 124 ° C, preferably less than 123.5 ° C., preferably less than 123 ° C., preferably less than 122.5 ° C., preferably less than 122 ° C., preferably less than 121.5 ° C., preferably less than 121 ° C. ° C, preferably less than 120.5 ° C, preferably less than 120 ° C, preferably less than 1 19.5 ° C, preferably less than 1 19 ° C, preferably less than 1 18.5 ° C, preferably less than 1 18 ° C, preferably less than 1 17.5 ° C, preferably less than 1 17 ° C, preferably less than 1 16.5 ° C, preferably less than 1 16 ° C preferably less than 1 15.5 ° C, preferably less than 1 15 ° C, preferably less than 1 14.5 ° C, preferably less than 1 14 ° C, preferably less than 1 13.5 ° C C, preferably below 13 ° C, preferably below 12.5 ° C, preferably below 12 ° C, preferably less than 1 1 1, 5 ° C, preferably less than 1 1 1 ° C, preferably less than 1 10.5 ° C, preferably less than 1 10 ° C, preferably less than 107.5 ° C or preferably less than 105 ° C. Experiments conducted in the context of the present invention have found that ^the ^use of a polymer based on butene-rich butene-1, the melting temperature is preferably, for example less than 135 ° C to obtain a mixture ^of a polymer based on ^ethylene and ethylene-rich on ^the one hand and ^a polymer based on butene-rich butene-1 on ^the other hand, ^improves so Surprisingly the mechanical properties of foams based on butene and ^ethylene according to the present invention, obtained with this mixture.

A foam based on butene and ^ethylene according to the present invention may comprise at least one polymer based on butene and / or a polymer based on butene-rich butene-1, the determined by DSC melting point may be for example greater than 60 ° C, preferably greater than 70 ° C, preferably greater than 75 ° C, preferably greater than 80 ° C, preferably greater than 85 ° C, preferably greater than 90 ° C, preferably greater than 95 ° C, preferably greater than 100 ° C, preferably greater than 105 ° C, preferably greater than 106 ° C, preferably greater than 106.5 ° C, preferably greater than 107 ° C, preferably greater than 108 ° C, preferably greater than 109 ° C, preferably greater than 1 10 ° C, preferably greater than 1 1 1 ° C, preferably greater than 1 1 1, 5 ° C, preferably greater than 1 12 ° C, preferably above greater than 12.5 ° C, preferably greater than 13 ° C or preferably greater than 13.5 ° C. This allows for example to ^ensure good mechanical strength of the butene based foams and ^ethylene according to the present invention at a higher temperature.

The melting temperature ^of a polymer ^or copolymer can be determined for example by differential scanning calorimetry (DSC, differential scanning calorimetry). The melting temperature ^of a polymer or ^a copolymer may preferably be the melting temperature corresponding to the maximum (top) ^of a melting peak detected by DSC. The melting temperature ^of a polymer or ^a copolymer may also be a temperature range corresponding to a melting peak (beginning and end of peak) detected by DSC. The melting temperature ^of a polymer or ^a copolymer may also be an average of the start value and the end value ^of a temperature range corresponding to a melting peak detected by DSC (average value start and end value of the peak).

The melting temperature can for example be measured by DSC by heating a sample in a sealed capsule ^up to 180 ° C with a temperature ramp of 10 ° C per minute. Alternatively it is for example also possible to carry out a first heating ^up to 180 ° C with a temperature ramp of 10 ° C per minute, maintaining the temperature at 180 ° C for example for 5 minutes, cooling ^the sample ^up to - 20 ° C with a temperature ramp of 10 ° C per minute, maintaining ^the sample at - 20 ° C for example 5 minutes and then proceed to a second heated ^up to 180 ° C with a temperature ramp of 10 ° C per minute, to measure the melting temperature during this second heating. The melting temperature ^of a polymer or ^a copolymer may preferably be the melting temperature of the major form of this polymer or copolymer. The

melting temperature ^of a polymer ^or copolymer thus may preferably be the melting temperature corresponding to the detected peak in DSC, of which ^the area under the peak is the largest.

The melting temperature ^of a polymer or ^a copolymer may preferably be the melting temperature determined for the thermodynamically most stable form of this polymer or copolymer. For a polymer and / or a copolymer comprising several polymorphic forms, for example polybutene-1 and / or a copolymer comprising butene-1, the melting temperature of the polymer may be the melting temperature of the thermodynamically most stable form. of this polymer (for example Form I in the case of polybutene-1) or copolymer.

A foam based on butene and ^ethylene according to the present invention may comprise at least a polymer based on ^ethylene and ethylene-rich on ^the one hand and at least one polymer based on butene-rich butene-1 ^of on the other hand, so that the difference between the melting temperatures ^of a / the polymer based on ^ethylene and ethylene-rich on ^the one hand and ^a / the polymer based on butene-rich butene-1 d ^{on the} other hand may be for example less than 40 ° C, preferably less than 35 ° C, preferably less than 30 ° C, preferably less than 25 ° C, preferably less than 20 ° C, preferably less than 15 ° C, preferably less than 10 ° C, preferably less than 6 ° C, preferably less than 3 ° C, preferably less than 2 ° C. ^When using several polymers based ^on ethylene and ethylene-rich and / or more polymers based on butene-rich butene-1 the difference between the melting temperatures for each pair of polymers used can be for example less than 40 ° C, preferably less than 35 ° C, preferably less than 30 ° C, preferably less than 25 ° C, preferably less than 20 ° C, preferably less than 15 ° C, preferably less than 10 ° C, preferably less than 6 ° C, preferably less than 3 ° C, preferably less than 2 ° C. Experiments conducted in the context of the present invention have found that ^the use ^of a mixture comprising a polymer based on ^ethylene and ethylene-rich on ^the one hand and a polymer based on butene-rich butene 1 on ^the other hand, the melting temperatures are close / similar, allows ^to further improve the mechanical properties of the resulting foams. This may allow for example to ^avoid a too great difference in the properties and particularly for example in the viscosity and / or crystallinity of the polymer based on ^ethylene and ethylene-rich on ^the one hand and the polymer base butene-rich butene-1 on ^the other hand during the implementation and / or mixing and / or ^extrusion and / or counting and / or foaming. This can therefore possibly for example possible ^to improve the ^homogeneity of the mixture of polymers and thus help to facilitate or improve such implementation and / or mixing and / or ^extruding the mixture of polymers and / or recognition and / or stability of ^the interface between the phase rich in polybutene-1 and the phase rich in polyethylene and / or to improve the mechanical properties of the resulting foams.

A foam based on butene and ^ethylene according to the present invention may comprise at least a polymer based on ^ethylene and ethylene-rich on ^the one hand and at least one polymer based on butene-rich butene-1 ^of on the other hand, so that the difference between ^the melt index (melt flow index or melt flow rate), for example measured at 190 ° C with a standard weight of 2.16 kg (ISO 1133) ^of a / the polymer based on ^ethylene and ethylene-rich on ^the one hand and ^a / the polymer based on butene-rich butene-1 on ^the other hand can preferably be for example less than 25 g / 10 min, preferably minus 24 g / 10 min, preferably minus 23.5 g / 10 min, preferably minus 23 g / 10 min, preferably minus 20 g / 10 min, preferably minus 17.5 g / min. 10 min, preferably minus 15 g / 10 min, preferably minus 12.5 g / 10 min, preferably minus 10 g / 10 min, preferably minus 7.5. g / 10 min, preferably minus 5 g / 10 min, preferably minus 2.5 g / 10 min, preferably minus 2 g / 10 min, preferably minus 1, 5 g / 10 min, preferably minus 1.25 g / 10 min, preferably minus 1.2 g / 10 min, preferably minus 1 g / 10 min, preferably minus 0.8 g / 10 min, preferably minus 0 , 5 g / 10 min, preferably minus 0.3 g / 10 min, preferably minus 0.2 g / 10 min. ^When using several polymers based ^on ethylene and ethylene-rich and / or more polymers based on butene-rich butene-1 the difference between ^the index (melt flow index flow or melt flow rate) e.g. measured at 190 ° C. with a standard mass of 2.16 kg (ISO standard 1,133) for each pair of polymers used can preferably be, for example, less than 25 g / 10 min, preferably minus 24 g / 10 min, preferably minus 23.5 g / 10 min, preferably minus 23 g / 10 min, preferably minus 20 g / 10 min, preferably minus 17.5 g / 10 min, preferably minus 15 g. 10 min, preferably minus 12.5 g / 10 min, preferably minus 10 g / 10 min, preferably minus 7.5 g / 10 min, preferably minus 5 g / 10 min, preferably minus 2.5 g / 10 min, preferably minus 2 g / 10 min, preferably minus 1.5 g / 10 min, preferably minus 1.25 g / 10 min, preferably at least 1.2 g / 10 min, preferably at least 1 g / 10 min, preferably at least 0.8 g / 10 min, preferably at least 0.5 g / 10 min, preferably at least 0, 3 g / 10 min, preferably minus 0.2 g / 10 min. This can further allow for example to ^avoid a too great difference in the properties and particularly for example in the viscosity of the base polymer ^ethylene and ethylene-rich on ^the one hand and the polymer based on butene-rich butene-1 on ^the other hand, particularly in ^the molten state. So it can possibly also help to facilitate or improve such implementation and / or mixing and / ^or extrusion and / or accounting and / or stability of ^the interface between the rich phase polybutene-1 and the polyethylene-rich phase and / or to improve the properties

mechanical foams obtained.

The foams according to the present invention may also comprise at least one additive (filler). These additives may for example comprise at least one additive which improves the ^insulating properties and particularly thermal ^insulation, such as at least one additive comprising carbon black, carbon nanotubes, fullerenes and / or flakes ( flakes) / metal particles, in particular of flakes of ^aluminum. On the other hand, these additives may also comprise at least one additive which facilitates the implementation and / or foaming, such as for example at least one additive comprising talc, a mixture of talc and polyethylene, a mixture of talc and LDPE, one or more clays, titanium dioxide, silicon dioxide, Γ EVA and / or one or more esters of ^fatty acid and / or glycerol esters, such as one or more stearate (s), as for example barium stearate, sodium stearate, glycerol stearate and / or alpha-glycerol monostearate and / or one or more amides of ^fatty acid, such as for example stearamide or palmitamide, and / or at least one derivative of ^at least one of these compounds / additives and / or a mixture ^of at least two of these compounds / additives. In addition, at least one additive may also comprise for example at least one stabilizer, at least one ^UV absorber, at least one plasticizer and / or at least one flame retardant and / or at least one derivative ^of at least one of these compounds / additives and / or a mixture ^of at least two of these compounds / additives. Foams according to the present invention based ^on ethylene and butene may for example have open cells and / or closed cells. Open cell and / or closed cells can be obtained for example according to the conditions ^of extrusion and / or foaming. Open cells may for instance also be obtained by mechanical perforation of closed-cell foams or by means of temperature (temperature of implementation when enough / higher foaming) permitting ^the at least partial opening of the cell walls. The nature of the cells of the foams obtained can, for example, influence their properties. Indeed, closed cell foams may for example be rigid and / or less flexible / flexible and / or less compressible. ^When using ^a mixture ^of a polymer based on ^ethylene and ethylene-rich on ^the one hand and polybutene-1 (butene-1 homopolymer) on ^the other hand, is observed phase separation due to ^{incompatibility} between ^the phase of ethylene or polyethylene rich phase and the polybutene-1 rich or polybutene-1. Moreover, the foams obtained in this case have poor mechanical properties. Indeed, the mixture, which contains nodules / core polybutene-1 or high polybutene-1 dispersed in a phase polyethylene or rich polyethylene is weakened because ^the interface between the nodules of polybutene-1 or rich polybutene-1 and the polyethylene or the polyethylene-rich phase is fragile. Cracks propagate easily between and especially at the interfaces between polybutene-1 or polybutene-1-rich nodules and polyethylene or the polyethylene-rich phase. The ^{incompatibility} between polyethylene and polybutene-1 therefore leads accordingly to poor mechanical properties.

A phase rich in polyethylene may for example be a phase comprising for example at least 50%, preferably at least 51%, preferably at least 55%, preferably at least 60%, preferably at least 65%, preferably at least 55%, preferably at least 70%, preferably at least 75%, preferably at least 80%, preferably at least 85%, preferably at least 90%, preferably at least 95%, preferably at least 97%, preferably at least 98%, preferably at least 99%, preferably at least 99.5%, preferably at least 99.9%, preferably at least 99.99%, preferably at least 99.999% by weight, polyethylene and / or ^ethylene. A phase and / or a nodule / nuclei rich in polybutene-1 may mean for example a phase and / or a nodule / nuclei comprising for example at least 50%, preferably at least 51%, preferably at least 55%, preferably at least 60%, preferably at least 65%, preferably at least 70%, preferably at least 75%, preferably at least 80%, preferably at least 85%, preferably at least 90%, preferably preferably at least 95%, preferably at least 97%, preferably at least 98%, preferably at least 99%, preferably at least 99.5%, preferably at least 99.9%, preferably at least 99.99%, preferably at least 99%. at least 99.999% by weight of polybutene-1 and / or butene-1.

In addition, ^the ^use of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer ^and another ooléfine, such as ^ethylene, rich in butene-1, instead of polybutene-1 (butene-1 homopolymer), does not appear to make it possible ^to significantly improve the dispersion of the polybutene-1 or rich phase polybutene-1 in the polyethylene phase or rich in polyethylene. Indeed, ^the ^use of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer ^and o another olefin such as ^ethylene, butene-1 rich, but nevertheless comprising a further ooléfine, such as ^ethylene (which could potentially play a role of ^counting), does not improve the recognition and the dispersion phase of polybutene-1 rich or polybutene-1 in the phase rich in polyethylene or polyethylene. The size of the nodules of the polybutene-1 or polybutene-1-rich phase hardly changes (does not decrease significantly, but remains similar, see Figure 1 and 2). The rate ^of ooléfine and / or e.g. ^ethylene ^a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a copolymer butene-1 and ^another ooléfine, such as ^ethylene, rich in butene-1, does not seem sufficient to improve the dispersion of the polybutene-1 phase or high polybutene-1 and / or to improve the

recognition of the polybutene-1 phase or high polybutene-1 and the phase rich in polyethylene or polyethylene and / or to act as counting between the two phases, especially at ^the interface therebetween.

However, ^the ^use of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer and ^a ooléfine another, such as ^ethylene, rich in butene-1, however, surprisingly makes it possible to ^obtain foams having good mechanical properties. Indeed, there is no deterioration of foams in case of mechanical stress and particularly in case of repeated mechanical stress. The formation of cracks / cracks is not observed. This may be due for example to a lower degree of crystallinity for a butene-based polymer rich in butene-1, whose melting point is, for example, less than 135 ° C., and / or particularly for a butene-butene copolymer. 1 and ^another ooléfine, such as ^ethylene, rich in butene-1, which results in a lower crystallinity in the nodules of polybutene-1 or high polybutene-1 dispersed in the polyethylene or in a rich phase polyethylene. A lower crystallinity of the polybutene-1 or polybutene-1-rich nodules dispersed in the polyethylene or in a polyethylene-rich phase may, for example, lead to a more amorphous and / or predominantly amorphous interface between the two phases. This can potentially allow for example to promote and / or ^improve the ^{interpenetration} of the two phases at ^the interface therebetween, so that ^the interface between the two phases can be enhanced.

The present invention also relates to a foaming process to obtain foams based ^on ethylene-butene according to the present invention, wherein at least a polymer based on ^ethylene and ethylene-rich and ^that at least one base polymer butene-rich butene-1, the melting temperature of the latter being less than 135 ° C, are foamed ^by means ^of at least one foaming agent. In the foaming process according to ^the invention, foaming and / ^or extrusion may / may for example be carried out (s) with temperature implemented during foaming and / or ^extrusion of less than 150 ° C, preferably less than 145 ° C, preferably less than 140 ° C, preferably less than 135 ° C, preferably less than 132.5 ° C, preferably less than 130 ° C, preferably less than 127.5 ° C C, preferably below 126 ° C, preferably below 125 ° C, preferably below 122.5 ° C, preferably below 120 ° C, preferably below 17.5 ° C, preferably below at 1 16 ° C, preferably below 1 15 ° C, preferably below 1 14.5 ° C, preferably below 1 14 ° C, preferably below 1 13.5 ° C, preferably below 1 13 ° C, preferably less than 12.5 ° C, preferably less than 1 12 ° C, preferably below 1 1 1, 5 ° C, preferably below 1 1 1 ° C, preferably below 1 10.5 ° C, preferably below 1 10 ° C, preferably below 109.5 ° C, preferably below 109 ° C. The implementation temperature during foaming preferably may for example correspond to the mass in maximum die temperature during ^the extrusion and / or foaming.

In the foaming process according to ^the invention, the implementation of temperature during foaming and / or ^extrusion (which may for example correspond to the mass temperature at full die) may for example be between 40 ° C and 150 ° C, preferably 50 ° C and 140 ° C, preferably between 90 ° C and 130 ° C, preferably between 100 ° C and 120 ° C, preferably between 102 ° C and 1 17.5 ° C preferably between 105 ° C and 1 16 ° C, preferably between 106 ° C and 1 15.5 ° C, preferably between 107 ° C and 115 ° C, preferably between 107.5 ° C and 1 14.5 ° C, preferably between 108 ° C and 14 ° C.

Too high a temperature or too low during foaming and / or ^extrusion may for example cause uncontrolled foaming and / or ineffective and / or inhomogeneous. Under these conditions, it can even be difficult or impossible to ^obtain such a relatively homogeneous foam and / or foam with a certain dimensional stability and / or foam with well-defined private property. Moreover, it can for example also be very difficult in these conditions to ^obtain and / or to vary the desired properties. Indeed, the implementation temperature during foaming and / or ^extrusion is such an important parameter, which can help control foaming. A monitoring implementation temperature during foaming and / or ^extrusion thus allows, if necessary, to ^obtain homogeneous foams and / or foams having a certain dimensional stability and / or foams with properties specific and well defined. The experiments conducted in the context of the present invention have determined that, in the foaming method according to ^the invention, during the implementation of temperature foaming and / or ^extrusion (which may preferably correspond, for example to the die bulk temperature) may for example correspond to or be greater than the glass transition temperature or the softening point or the corresponding temperature the top of the melting peak (determined by DSC) or preferably at the polymer melting temperature based ^on ethylene and / or butene-based polymer and rich in butene-1. A temperature can correspond for example to the glass transition temperature or softening point or at a temperature corresponding to the start of the melting peak (determined by DSC) or to the polymer melting temperature based ^on ethylene and ethylene-rich and / or butene-based polymer rich in butene-1, if it is equal to said temperature plus or minus 50 ° C, preferably plus or minus 40 ° C, preferably plus or minus 30 ° C, preferably plus or minus 25 ° C, preferably plus or minus 22.5 ° C, preferably plus or minus 20 ° C, preferably plus or minus 17.5 ° C, preferably plus or minus 15 ° C, more preferably or at least 14 ° C, preferably plus or minus 13 ° C, preferably plus or minus 12 ° C, preferably plus or minus 11 ° C, preferably plus or minus 10 ° C, preferably plus or minus 9 ° C C, preferably plus or minus 8 ° C, preferably plus or minus 7 ° C, more or less 6 ° C preferably plus or minus 5 ° C, preferably plus or minus 4 ° C, preferably plus or minus 3 ° C, preferably plus or minus 2 ° C, preferably plus or minus 1 ° C C, preferably plus or minus 0.75 ° C, preferably plus or minus 0.5 ° C, preferably plus or minus 0.1 ° C, preferably plus or minus 0.01 ° C or preferably more or less 0.001 ° C.

The experiments conducted in the context of the present invention have determined that, in the foaming method according to ^the invention, the implementation of temperature during foaming and / or ^extrusion (which may preferably correspond, for example at maximum die temperature) may, for example, be within plus or minus 50 ° C, preferably at plus or minus 40 ° C, preferably at plus or minus 30 ° C, preferably at plus or minus 25 ° C, preferably at plus or minus 22.5 ° C, preferably at plus or minus 20 ° C, preferably at plus or minus 17.5 ° C, preferably at +/- 15 ° C, preferably at plus or minus 14 ° C, preferably at plus or minus 13 ° C, preferably at plus or minus 12 ° C, preferably at plus or minus 1 1 C, preferably to within + 10 ° C, preferably to plus or minus 9 ° C, preferably at plus or minus 8 ° C, preferably at plus or minus 7 ° C, preferably at plus or minus 6 ° C, preferably at plus or minus 5 ° C, preferably at plus or minus 4 ° C near, preferably within plus or minus 3 ° C of preferably plus or minus 2 ° C or preferably roughly 1 ° C than the polymer melting temperature based ^on ethylene and / or butene-based polymer rich in butene-1. This allows a good mix of polymers and effective foaming. On ^the other hand, experiments in the context of the present invention have also determined that, in the foaming method according to ^the invention, the implementation of temperature during foaming and / or ^extrusion (which can for example preferably correspond to the temperature in the form of a spinneret) may for example preferably be less than 150 ° C. This makes it possible, for example, to retain good control of the foaming. Indeed, beyond this temperature control foaming seems difficult and foaming seems ineffective. The products obtained may for example tend to collapse instead of forming a foam having good dimensional stability.

(The) agent (s) of foaming (s) used in the foaming process according to ^the invention may (can), for example comprise at least one chemical foaming agent and / or at least one physical foaming agent. A chemical foaming agent may for example comprise at least one compound or a mixture of compounds, which can release at least one gas (such as ^nitrogen or C0 _2). A chemical foaming agent may for example comprise ^{azodicarbonamide,} ^of azodiisobutyronitrile, the

benzolsulfonylhydrazide, 4,4-oxybenzolsulfonylsemicarbazide, 4,4-oxybis (benzolsulfonylhydrazid), diphenylsulfon-3,3-disulfonylhydrazide, p-toluolsulfonylsemicarbazide, N, N-dimethyl-N, N-dinitrosoterephthalamide, trihydrazintriazine , N = N-dinitrosopentamethylenetetramine,

dinitrosotriméthyltriamine of ^sodium hydrogencarbonate, sodium bicarbonate, of carbonate ^ammonium, the ^ammonium bicarbonate, potassium carbonate, diazobenzene of diazotoluène, ^the hydrazodicarbonamide of diazoisobutyronitrile carboxylate, barium, 5-hydroxytétrazole and / or at least one derivative and / or a mixture ^of at least two of these compounds.

A physical foaming agent used in the foaming process according to ^the invention may for example comprise at least one gas or at least one liquid, which may preferably be volatile. A physical foaming agent may for example include carbon dioxide, ^nitrogen, ^argon, ^water, ^air, ^helium, aliphatic hydrocarbons with 1 to 6 carbon atoms, aliphatic alcohols having 1 to 3 carbon atoms, fully or partially halogenated aliphatic hydrocarbons having 1 to 4 carbon atoms, methane, ^ethane, propane, n-butane, ^isobutane, n- pentane, ^isopentane, neopentane, ^hexane, ^of isohexane, ^heptane, ^the octane, methylpentane, dimethylpentane, butene, pentene, 4-methylpentene, ^the hexene, 2,2-dimethylbutane, ^of petroleum ether, methanol, ^ethanol, n-propanol, ^isopropanol, aliphatic hydrocarbons completely or partially chlorinated and / or fluorinated, trichlorofluoromethane, trichloromethane, tetrachloromethane, chlorofluoromethane, methyl chloride, methylene chloride of the ^ethyl, the chloride of ^ethylene, 1, 1, 1-trichloroethane, 1, 1, 1 - trifluoroethane, dimethyl ether and / or at least one derivative ^of at least one of these compounds and / or a mixture ^of at least two of these compounds.

In the foaming process according to ^the invention and to obtain foams of ^the invention, foaming may for example take place ^by means of mechanical means, such as a reactor and / or a mixer and / or extruder. In addition, ^the foaming agent may for example be added to the high polymer based on ^ethylene and the polymer based on butene-rich butene-1 ^using mechanical means, such as a reactor and / or a mixer and / or extruder, in the foaming method according to ^the invention and to obtain foams of ^the invention. In the foaming process according to ^the invention and to obtain foams of ^the invention, foaming can therefore preferably be achieved for instance by extrusion. This can allow for example an easy and effective foaming.

In addition, it is possible ^to obtain either foams based ^{ethylene-butene} according to the present having open cells and / or closed cells through a foaming process according to ^the invention, for example according to the conditions ^extrusion and / or foaming. Conditions for example to ^obtain closed-cell foams are given in the following examples. Open cell foams may still be obtained for example through temperature conditions (work during foaming processing temperature enough / highest) for ^the at least partial opening of the cell walls. The nature of the cells of the foams obtained can, for example, influence their properties. Indeed, closed cell foams can for example be rigid and / or less flexible / flexible and / or less compressible than open cell foams.

Examples: 1) Dispersion

A- mixture of polyethylene and polybutene-1 made for comparison to a mixture ^of a polymer based on ^ethylene and ethylene-rich on ^the one hand and polybutene-1 (homopolymer) of ^the other part (70% by weight of LDPE / LDPE, 2601 TX17 from SABIC and 30% by weight of polybutene-1, LYONDELLBASELL homopolymer PB 1), there is a phase separation due to ^{incompatibility} between the polyethylene or ethylene-rich phase and the phase of polybutene-1 or high polybutene-1 (see Figure 1).

Figure 1 is an image ^of a section through the mixing obtained ^using ^an electronic microscope. There are small nuclei / nodules of polybutene-1 or polybutene-1-rich dispersed in a polyethylene phase or rich in polyethylene.

Moreover, the foams obtained in this case have poor mechanical properties.

Indeed, the mixture, which contains nodules of polybutene-1 or high polybutene-1 dispersed in a phase polyethylene or rich polyethylene is weakened because ^the interface between the nodules of polybutene-1 or high polybutene 1 dispersed in a polyethylene phase or rich in polyethylene is fragile.

In case of mechanical stress and particularly in case of repeated mechanical stress, there is a degradation of the foams and their properties, more

particularly for example the formation of cracks / cracks.

Cracks propagate easily between and especially at the interfaces between polybutene-1 or polybutene-1-rich nodules and polyethylene or the polyethylene-rich phase.

The ^{incompatibility} between polyethylene and polybutene-1 therefore leads accordingly to poor mechanical properties.

B Mixture ^of a polymer based on ^ethylene and ethylene-rich and polymer based on butene-rich butene-1

To a mixture ^of a polymer based on ^ethylene and ethylene-rich on ^the one hand and polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C (e.g. a copolymer), on ^the other hand, there is also a phase separation due to ^{incompatibility} between the phase rich in polyethylene rich phase and polybutene-1 (see Figure 2). The mixing conditions are identical.

Figure 2 is an image ^of a section ^of a mixture of 70% by weight of LDPE / LDPE 2601TX17 SABIC and 30% by weight ^of a polymer based on butene-rich butene-1, the melting point is for example less than 135 ° C, KOATTRO KT AR 05, Tf _US = 1 14 ° C, of LYONDELLBASELL, obtained ^using ^an electron microscope (the mixing conditions are identical to the conditions used for mix of polyethylene and ^a butene-1 homopolymer described above). There are small nuclei / nodules of polybutene-1 or polybutene-1-rich dispersed in a polyethylene phase or rich in polyethylene.

^The use ^of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer and ^another ooléfine such as ^ethylene, rich in butene-1, instead of polybutene-1 (butene-1 homopolymer), does not appear to make it possible ^to significantly improve the dispersion of the phase polybutene-1 or high polybutene -1 in the polyethylene phase or rich in polyethylene. Indeed, ^the ^use of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer ^and another ooléfine, such as ^ethylene, rich in butene-1, but nevertheless comprising another ooléfine, such as ^ethylene (which could potentially play a role of counting), n ^', however, improves accounting and dispersing the polybutene-1 or polybutene-1-rich phase in the polyethylene or polyethylene-rich phase. The size of the nodules of the polybutene-1 or polybutene-1-rich phase hardly changes (does not decrease significantly, but remains similar, see Figure 1 and 2).

The rate ^of ooléfine and / or e.g. ^ethylene ^a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a copolymer butene-1 and ^another ooléfine, such as ^ethylene, rich in butene-1, does not seem sufficient to improve the dispersion of the polybutene-1 phase or high polybutene-1 and / or to improve the

However, ^the ^use of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer and ^a ooléfine another, such as ^ethylene, rich in butene-1, however, surprisingly makes it possible to ^obtain foams having good mechanical properties.

Indeed, there is no deterioration of foams in case of mechanical stress and particularly in case of repeated mechanical stress. The formation of cracks / cracks is not observed. This may be due for example to a lower degree of crystallinity for a butene-based polymer rich in butene-1, whose melting point is, for example, less than 135 ° C., and / or particularly for a butene-butene copolymer. 1 and ^another ooléfine, such as ^ethylene, rich in butene-1, which results in a lower crystallinity in the nodules of polybutene-1 or high polybutene-1 dispersed in the polyethylene or in a rich phase polyethylene. A lower crystallinity of the polybutene-1 or polybutene-1-rich nodules dispersed in the polyethylene or in a polyethylene-rich phase may, for example, lead to a more amorphous and / or predominantly amorphous interface between the two phases. This may eventually allow for example to promote and / or ^improve

^{interpenetration} of the two phases at ^the interface therebetween, so that ^the interface between the two phases can be enhanced.

2) Foams based ^on ethylene-butene according to ^the invention and obtaining these foams

Foams according to the present invention were prepared with three different compositions (see entries 1, 2 and 3 of Table 1). In addition, for comparison, a PE-BD / LDPE foam was also prepared under similar conditions (see entry 4, Table 1).

Table 1

In addition, each mixture (1, 2, 3 and 4) further comprises a mixture of several additives:

- 3% by weight (based on the weight of the mixtures of the table) ^of an additive

comprising a mixture ^of glycerol ester (ATMER 122, Croda, 70 mass%) ^and EVA (30 wt%), - 3% by weight (based on the weight of the mixtures of the table) ^of an additive comprising a mixture of 40% of flake ^aluminum in 60% of LDPE / LDPE, and

- 2% by weight (based on the weight of the mixtures of the table) ^of an additive

comprising a mixture of 50% by weight of talc in 50% by weight of PE

BD / LDPE.

The mixtures 1, 2, 3 and 4 are foamed by extrusion ^using ^isobutane through an extruder and using the parameters shown in Table 2.

Table 2

Foaming and / ^or extrusion is / are performed (s) with a temperature of implementation of between 108.8 ° C and one 10.7 ° C. This temperature is in this case the temperature in a die mass. The maximum die mass temperature is therefore in all cases less than 150 ° C. For foams based ^on ethylene and based on butene according to the present invention (see entries 1 to 3 of Table 1) and for the corresponding foaming process, the implementation temperature corresponds for example to plus or minus 5 ° C near the melting temperature of the polymer based on ^ethylene and / or to the polymer melting temperature based on butene-rich butene-1. The foaming is effective and the foams thus obtained for each mixture (1, 2 and 3) have good dimensional stability (no collapse of foams during foaming, nor subsequently at room temperature). The foams obtained are closed cell foams.

In addition, the foams thus obtained for each mixture (1, 2 and 3) exhibit good mechanical properties despite ^the ^{incorporation} of a polymer based on butene-rich butene-1.

Indeed, even in the case of mechanical stress and / or stress, no degradation of the foams or their properties is observed (see also the results of the compression tests below). In particular, we ^do not observe ^spalling or training fissures, cracks, crevices, or ^other signs of deterioration of the foam, even under stress repeatedly and / or for repeated mechanical stress.

Foams thus obtained for each mixture (1, 2, 3 and 4) were characterized by measuring their density and the number of cells per square centimeter.

Table 3

Foams obtained for each mixture (1, 2, 3 and 4) were also characterized by measuring their density after a heat treatment at 50 ° C allowing degassing (see Table 4).

Table 4

It is observed that the density of the foams according to ^the invention comprising a polymer based on butene-rich butene-1 (mixture 1, 2 and 3) decreases during the degassing (see Table 4). In addition, the foams according to the present invention obtained for each mixture (1, 2 and 3) have excellent flexibility / flexibility (see Table 5 and Figure 3). The

flexibility / flexibility of the foams obtained with the mixtures according to the present invention (mixtures 1, 2 and 3) is higher than that ^of a polyethylene foam (mixture 4). Indeed, at equal compression, the flexibility / flexibility of the foams obtained with the mixtures according to the present invention (mixtures 1, 2 and 3) comprising a butene-based polymer and rich in butene-1 is higher and the stress is therefore consequently less important (see Table 5 and Figure 3).

We also observe that the flexibility / flexibility of the foams according to the present invention (mixtures 1, 2 and 3) increases and the stresses decrease accordingly when the rate ^of a polymer based on butene-rich butene-1 increases in the mixture used for foaming (see Table 5 and Figure 3). Table 5

The relative stress-strain characteristics in compression (see Table 5 and Figure 3) are determined by a compression test by measuring the stress (in N / mm ² ) as a function of the compression ratio (in%).

On ^the other hand, the thermal conductivity of the foams obtained was also measured (see Table 6). The thermal conductivity can give an indication about the properties ^of thermal insulation foams.

Table 6

It is found that the thermal conductivity of foams according to the present invention comprising a polymer based on butene-rich butene-1 (mixture 1, 2 and 3) is lower than that ^of a polyethylene foam. The properties ^of thermal insulation foam according to the present invention comprising a polymer based on butene-rich butene-1 (mixture 1, 2 and 3) are therefore accordingly better. In addition, the thermal conductivity decreases when the butene-based polymer content rich in butene-1 increases. The properties ^of thermal insulation foams according to present invention are therefore improved by ^the addition ^of a polymer based on butene-rich butene-1 (mixture 1, 2 and 3).

Open cell foams may for example be obtained similarly, but using temperature (temperature of implementation when enough / higher foaming) permitting ^the at least partial opening of the cell walls.

3) Tensile tests and comparison of properties

As a comparison, ± 30 x 10mm foam rectangles were produced with similar mixtures of low density polyethylene

homopolymer of butene-1, or a butene-based copolymer rich in butene-1, whose melting point is for example less than 135 ° C (see Table 7). The additives used are also indicated in Table 7, as well as some properties of the foams obtained.

Table 7

The resulting foams were compared in tensile tests in the direction of ^extrusion (speed 500 mm / min). ^Input 1 corresponds to a low density polyethylene foam and used as reference. All samples were degassed at room temperature for 15 days prior to tensile testing. Table 8 shows the results of the tensile tests on this set of foams.

Table 8

With respect to a polyethylene foam (input 1), it is observed that ^the elongation at break at ^a tensile stress significantly decreases for foams comprising a blend ^of homopolymer of polybutene-1 and polyethylene (see entries 1 and 2, 3 and 4 of Table 8).

^The elongation at break decreases ^even more, than the amount ^of homopolymer of butene-1, added to polyethylene is important. Indeed, the resulting mixture, which contains nodules of polybutene-1 or high polybutene-1 dispersed in a phase polyethylene or rich polyethylene is weakened because ^the interface between the nodules of polybutene-1 or high polybutene -1 dispersed in a polyethylene phase or rich in polyethylene is fragile. This may contribute to ^the appearance of cracks and degradation of the resulting foams. The foaming ^of a mixture of polybutene-1 and polyethylene thus leads to brittle foams with poor mechanical properties, which can rupture and deteriorate easily, especially when loaded.

For against, ^the addition ^of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, and / or especially ^of a butene-1 copolymer ^and another ooléfine, such as ^ethylene, butene-1 rich, surprisingly makes it possible to ^obtain foams having good mechanical properties.

Indeed, compared with a polyethylene foam (input 1), it is observed that ^the elongation at break at ^a tensile load increases for foams according to the present invention comprising polyethylene as well as ^a polymer or copolymer based on butene and rich in butene-1, whose melting temperature is for example less than 135 ° C (see entries 1 and 5, 6 and 7 of Table 8).

^The elongation at break increases all ^the more as the amount of polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, added to the polyethylene is important.

^The use ^of a polymer based on butene-rich butene-1, whose melting temperature is for example less than 135 ° C, thus surprisingly makes it possible to maintain good mechanical properties and even improved.

Claims

claims

1) foam based on butene and ^ethylene, characterized in ^that it comprises at least a polymer based on ^ethylene and ethylene-rich and ^that at least one polymer based on butene-rich butene-1, the melting temperature of the latter being less than 135 ° C.

2) butene based foam and ^ethylene according to Claim 1, characterized in ^that it comprises at least a polymer based on ^ethylene and ethylene-rich selected from the following group: polyethylene very low density (PE -TBDA LDPE), linear low density polyethylene (PE-BDL / LLDPE), low density polyethylene (PE-BD / LDPE), medium density polyethylene (PE-MD / MDPE), high density polyethylene (PE-HD / HDPE), very low molecular weight polyethylene (ULMWPE), high molecular weight polyethylene (HMWPE).

3) butene based foam and ^ethylene according ^to one of claims 1 or 2, characterized in ^that it comprises at least a polymer based on ^ethylene and ethylene-rich, which comprises at least 50% by weight ^ethylene and / or whose melting temperature is determined by DSC between 30 ° C and 160 ° C and / or ^whose melt index is between 0.1 and 35 g / 10 min.

4) foam based on butene and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one polymer based on butene-rich butene-1 which comprises at least 50% by weight of butene-1 and / or ^whose melt index is between 0.4 and 0.6 g / 10 min. 5) foam based on butene and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one polymer based on butene-rich butene-1 which comprises at least 50% by weight of butene-1 and / or ^whose melt index is between 0.4 and 0.6 g / 10 min.

6) foam based on butene and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one polymer based on butene-rich butene-1, which is a copolymer and / or copolymer comprising butene-1 and at least one other oolefin.

7) foam based on butene and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one polymer based on butene-rich butene-1, which is a copolymer comprising butene-1 and ^ethylene.

8) butene based foam and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one polymer based on butene-rich butene-1, the melting temperature determined by DSC is less at 120 ° C and / or is greater than 60 ° C.

9) foam based on butene and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one polymer based on butene-rich butene-1 and at least one polymer based ^on ethylene and rich in ethylene selected such that the difference between the melting points determined by DSC ^of a / the polymer based on butene-rich butene-1 on ^the one hand and ^a / the polymer based on ^ethylene and ethylene-rich on ^the other hand is less than 40 ° C.

10) based foam butene and ^ethylene according ^to one of the preceding claims, characterized in ^that at least one polymer based on butene-rich butene-1 and at least one polymer based on ^ethylene and rich ethylene selected such that the difference between ^the melt index ^of a / the polymer based on butene-rich butene-1 on ^the one hand and ^a / the polymer based on ^ethylene and ethylene-rich ^{on the} other hand, less than 25 g / 10 min or less than 1 g / 10 min.

1 1) Basic foam butene and ^ethylene according ^to one of the preceding claims, characterized in ^that it comprises at least one additive chosen from:. at least one additive which improves the ^insulating properties and particularly thermal ^insulation, an additive comprising carbon black, carbon nanotubes, fullerenes, flakes (flakes) / metal particles, flakes ^of aluminum, less an additive that facilitates the implementation and / or foaming, at least one additive comprising talc, a mixture of talc and polyethylene, a mixture of talc and LDPE, one or more clays, titanium dioxide, silicon dioxide, Γ EVA and / or one or more esters of ^fatty acid and / or one or more amides of ^fatty acid and / or one or more esters of glycerol, one or more stearate (s), stearate barium, sodium stearate, stearate of glycerol and / or alpha-glycerol monostearate, at least one stabilizer, at least one ^UV absorber, at least one plasticizer and / or at least one flame retardant and / or at least one derivative of ^at least one of these compounds / additives and / or a mixture ^of at least two of these compounds / additives.

12) A process for foaming to obtain foams based ^on ethylene and butene, characterized in ^that at least one polymer based ^on ethylene and ethylene-rich and ^that at least one polymer based on butene-rich butene-1, the melting temperature of the latter being less than 135 ° C, are foamed ^by means ^of at least one foaming agent. 13) A method of foaming for obtaining based foams of ^ethylene and butene as claimed in claim 12, characterized in that the foaming can be carried out (e) with a temperature of implementation during foaming and / or ^the extrusion of less than 150 ° C.

14) A method of foaming for obtaining based foams of ^ethylene and butene according ^to one of claims 12 or 13, characterized in that the foaming can be carried out (e) with a temperature of implementation during foaming and / or ^extrusion which may correspond to or be greater than the glass transition temperature or softening point or at a temperature corresponding to the start of the melting peak (determined by DSC) or to the polymer melting temperature based ^on ethylene and ethylene-rich and / or polymer based on butene-rich butene-1.

15) A method of foaming for obtaining based foams of ^ethylene and butene according ^to one of claims 12 to 14, characterized in that the foaming is carried out ^using ^at least one physical foaming agent and / or chemical selected from: at least one compound or a mixture of compounds, which can release at least one gas, ^{azodicarbonamide,} ^of azodiisobutyronitrile, the benzolsulfonylhydrazide of oxybenzolsulfonylsemicarbazide 4,4, 4,4-oxybis ( benzolsulfonylhydrazid), diphenylsulfon-3,3-disulfonylhydrazide, p-toluolsulfonylsemicarbazide, N, N-dimethyl-N, N-dinitrosoterephthalamide, trihydrazintriazine, N = N-

Dinitrosopentaméthylèntétramine, the dinitrosotriméthyltriamine of ^sodium hydrogencarbonate, sodium bicarbonate, ^ammonium carbonate, the ^ammonium bicarbonate, potassium carbonate, diazobenzene of diazotoluène, ^the hydrazodicarbonamide of diazoisobutyronitrile of barium carboxylate, from 5- hydroxytétrazole, at least one gas or at least one liquid, which may preferably be volatile, carbon dioxide, ^nitrogen, ^argon, ^water, ^air, ^helium, of aliphatic hydrocarbons with 1 to 6 carbon atoms, aliphatic alcohols having 1 to 3 carbon atoms, fully or partially halogenated aliphatic hydrocarbons having 1 to 4 carbon atoms, methane, ^ethane, propane, n- butane, ^isobutane, n-pentane, ^isopentane, neopentane, ^hexane, ^of isohexane, ^heptane, ^the octane, methylpentane, dimethylpentane, butene, pentene, 4-methylpentene, ^hexene, 2,2-dimethylbutane, ^of petroleum ether, methanol, ^ethanol, n-propanol, ^isopropanol, aliphatic hydrocarbons completely or partially chlorinated and / or fluorinated hydrocarbons, trichlorofluoromethane,

trichloromethane, tetrachloromethane, chlorofluoromethane, methyl chloride, methylene chloride, ^ethyl chloride, the chloride ^of ethylene, 1, 1, 1 - trichloroethane, 1, 1, 1 -trifluoroéthane, dimethyl ether and / or at least one derivative ^of at least one of these compounds and / or a mixture ^of at least two of these compounds