EP2328941A1

EP2328941A1 - Polyolefin derived from renewable resources, and method for producing same

Info

Publication number: EP2328941A1
Application number: EP09748422A
Authority: EP
Inventors: Guillaume Le; Jean-Laurent Pradel; Samuel Devisme; Thomas Roussel; Jean-Luc Dubois
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2008-09-22
Filing date: 2009-09-22
Publication date: 2011-06-08
Also published as: CN102224176A; FR2936249A1; FR2936249B1; WO2010031984A1; US20110196114A1; US8338549B2; JP2012503063A

Abstract

The invention relates to a polymer obtained by polymerizing olefins having 6 to 9 carbon atoms and partially derived from renewable resources. In particular, the polymer according to the invention can be derived from vegetable oil or animal fat. The invention also relates to the method for producing the polymer.

Description

POLYOLEFIN FROM RENEWABLE RESOURCES AND ITS

MANUFACTURING PROCESS

Field of the invention

The present invention relates to a polymer made from renewable raw materials and its method of manufacture.

More specifically, the subject of the invention is a polymer obtained by polymerization of an olefin, derived from renewable materials, having a number of carbons in the range from 6 to 9.

Among the families of polymers, polymers obtained from olefins (or even polyolefins) have very varied properties (for example mechanical properties or melt viscosity). When these polyolefins are oligomers (that is to say when they have a number average molecular weight less than or equal to 2000 g / mol), they are in the liquid or viscous state at room temperature and can be used, for example, as lubricant. When the average molar mass is greater than 2000g / mol, the polyolefins can be solid at room temperature. It is thus possible to manufacture from these polyolefins films, molded or injected parts, tubes or bottles by a variety of shaping techniques. They can be used in many fields, including packaging or automobiles. Polyethylene and polypropylene are the most common polyolefins. Polyolefins comprising olefins having a number of carbon atoms greater than or equal to 5 (for example in the range from 6 to 9) may also be mentioned. These olefins can be polymerized with each other or with other monomers. In particular, they can be polymerized with olefins having a small number of carbon atoms (usually 2 or 3). For example, from ethylene and an olefin having a number of carbon atoms greater than or equal to 5, a polyethylene, for example of the LLDPE (linear low density polyethylene) type, which is a random copolymer of ethylene and an additional olefin having a higher carbon number. The polyolefins can be obtained by the polymerization of olefins from petroleum products. To obtain these olefins, a process comprising a crude oil cracking stage followed by a steam cracking step of the alkanes produced during the previous cracking step is generally used. Various products are obtained, including olefins. A disadvantage of this cracking and steam-cracking process is that it requires large amounts of energy linked to a high temperature during the process (of the order of 800 ^° C. for the steam-cracking stage).

Another disadvantage is that the petroleum products obtained at the end of this process are very diverse: a mixture of products is obtained, among which olefins (but also aromatics, alkanes, etc.). The olefins produced are also diverse.

Olefins can be made from fossil (petroleum) resources by carrying out the oligomerization of ethylene, which is today the most common process. A broad overview of these processes is developed in encycolpédie Ullman 5 ^th Edition, Volume Al 3, pages 238 to 248. These processes produce a range of olefins of C4 / C6 to C20 and more. However, most of them to date produce mixtures of olefins, in particular many isomers, which must then be isolated in order to be polymerized. However, these separation processes, in particular the processes for separating the isomers, are complex and very expensive. Therefore, a process comprising a step for producing predominantly an olefin with a very limited number of isomers has great advantages. Another problem posed by polyolefins from petroleum products is the intense exploitation of fossil resources that inexorably leads to their depletion. The extraction becomes more and more difficult (deep wells), and this therefore requires heavy and expensive equipment. Similarly, a sharp increase in the price of petroleum products since the 1973 crisis has been observed. One consequence is the increase in manufacturing costs of polymers made mainly from petroleum products. For these reasons, polymers derived from renewable raw materials have become increasingly popular in recent years. Indeed, there may be mentioned for example polyesters such as poly (lactic acid) from the polymerization of lactide, a monomer synthesized from beet or corn for example. One can also mention the polyamide 11 obtained from oil extracted from the castor plant (marketed under the trade name Rilsan ^® by the Applicant). One of the advantages of these polymers derived from renewable raw materials concerns the carbon cycle: in fact, these plants absorb the atmospheric carbon dioxide (CO2) so that this carbon is said "Contemporary" unlike fossil carbon (eg from oil or coal). The use and release of fossil carbon causes its accumulation in the atmosphere and the imbalance of the carbon cycle.

In the application WO2008 / 067627, there is described a process for producing polyolefin from olefins comprising from 2 to 4 carbon atoms from renewable resources. In particular, the olefin synthesis step for the manufacture of this polyolefin comprises a biomass gasification step.

This step is carried out at a very high temperature (generally between HOO ⁰ C and

1300 ⁰ C), which implies high energy consumption for this step. If this energy is of fossil origin, then it contributes to the release of greenhouse gases (including CO2) causing the effect of accumulation.

To date, no one has been interested in the synthesis of polymers obtained from olefins having a carbon number in the range of 6 to 9 carbon atoms, derived from renewable resources. This is one of the objects of the present invention.

Surprisingly, the inventors have implemented a process for the industrial manufacture of polyolefins from renewable raw materials.

The method according to the invention makes it possible to overcome, at least in part, raw materials of fossil origin and to replace them with renewable raw materials.

The polyolefins obtained according to the process according to the invention can be used in all the applications in which it is known to use these same polymers derived from petroleum resources.

Summary of the invention

The invention relates to a method for producing a polymer obtained by polymerization of constituent monomers, at least one named olefin (a) is resulting at least partly from renewable resources and has the formula C _n HU wherein n is an integer in the range of from 6 to 9. The process according to the invention makes it possible to synthesize a novel polymer comprising contemporary carbon from olefins having a number of carbon atoms ranging from 6 to 9. Thus, another subject of the invention is a polymer that can be obtained by the process of the invention. The polymer according to the invention solves at least one of the following different problems. The fact that it includes contemporary carbon, this part of carbon does not contribute to the accumulation of CO2 in the atmosphere. The manufacture of this polymer can generate less greenhouse gases than the same polymers of fossil origin because the polymer according to the invention can be manufactured by a less energy consuming process. In addition, the method of manufacturing this polymer is facilitated in comparison with conventional methods using olefins from petroleum products because olefin (a) has fewer isomers. Another advantage is that the manufacturing process can be implemented in production units located at the place of production of the raw materials. In addition, the size of the production units of the process according to the invention is much smaller than the size of a refinery: the refineries are indeed large plants generally located far from the centers of production of raw materials and fed by pipelines. . In addition, the polymers according to the invention comprise olefins having a number of carbon atoms ranging from 6 to 9. These polymers can not be manufactured to the knowledge of the applicant from the known methods for the production of polymers. olefins from renewable resources: indeed, the olefins which constitute these polymers are obtained by fermentation of carbohydrates or by gasification of biomass; however, the fermentation of carbohydrates or the gasification of biomass does not allow the manufacture of olefins having a number of carbon atoms ranging from 6 to 9.

According to the process of the invention, the olefin (a) is obtained from a fatty substance consisting of a vegetable oil and / or an animal fat, which is extracted from renewable resources.

The method of manufacturing the polymer according to the invention comprises the following steps:

A. treating said fatty substance to form an olefin (a) comprising a number of carbon atoms in the range of 6 to 9;

B. polymerization of the constituent monomers of which at least one is the olefin (a). In step A, the fatty substance extracted from renewable resources is treated to form an olefin (a). According to the method, this step A comprises a dehydration reaction of an alcohol obtained from a fatty substance. To perform this step A of the manufacturing method according to the invention, the treatment step A of the body fatty acid comprises one or more reactions to form a saturated alcohol followed by a step of dehydrating said alcohol to form an olefin (a). This dehydration reaction can be written:

R-CHOH-CH-R 'O R-CH = CH-R' + H ₂ O with R being an alkyl group and R 'being either a hydrogen atom or an alkyl group.

According to the method of the invention, at least one fatty acid of the fatty substance comprises a C = C type unsaturation which is cut off. This cleavage is performed either by an oxidative cleavage reaction or by a cracking reaction. Saturated species having a carbon number ranging from 6 to 9 are then formed and comprising, depending on the conditions, an acid, ester, aldehyde or alcohol function.

Thus, the method of the invention relates to a process for producing a polymer, obtained from a fatty substance extracted from renewable resources and at least one fatty acid of the fatty substance comprises a type C unsaturation. = C, comprising the following steps:

A. manufacture of olefin (a) having a carbon number ranging from 6 to 9 by the following steps:

optionally a hydrolysis or transesterification step of the fatty substance to form, respectively, fatty acids or fatty esters;

an oxidative cleavage or cracking reaction of the fatty substance, fatty acids or fatty esters to form saturated species having a number of carbons ranging from 6 to 9, which, depending on the conditions, comprises an acid, ester, aldehyde or alcohol function ; an additional hydrogenation step when the function is aldehyde, acid or ester to form a saturated alcohol;

a dehydration step of the saturated alcohol obtained;

B. polymerization of the constituent monomers of which at least one is said olefin (a).

Other advantages and elements to be able to implement the invention are reported in the detailed description below.

Detailed description of the invention

The polymer according to the invention is obtained from olefin (a) derived from renewable raw materials. A renewable raw material is a natural resource, for example animal or vegetable, whose stock can be reconstituted over a short period on a human scale. In particular, this stock must be renewed as quickly as it is consumed. Plant matter has the advantage of being able to regenerate faster than resources from fossil materials.

Unlike materials from fossil materials, renewable raw materials contain ^14C . All carbon samples from living organisms (animals or plants) are actually a mixture of 3 isotopes: ¹² C (representing about 98.892% ), ¹³ C (about 1, 108%) and ¹⁴ C (traces: 1, 2.10-10%). The ¹⁴ C / ¹² C ratio of living tissues is identical to that of the atmosphere. In the environment, ¹⁴ C exists in two main forms: in the form of carbon dioxide (CO2), and in organic form, that is to say of carbon integrated in organic molecules. In a living organism, the ¹⁴ C / ¹² C ratio is kept constant by the metabolism because the carbon is continuously exchanged with the external environment. The proportion of ¹⁴ C being constant in the atmosphere, it is the same in the body, as long as it is alive, since it absorbs this ¹⁴ C in the same way as the ¹² C ambient. The average ratio of ¹⁴ C / ¹² C is equal to 1, 2xlθ- ¹² . ¹² C is considered stable, that is to say that the number of atoms of ¹² C in a given sample is constant over time. ¹⁴ C is radioactive, the number of atoms of ¹⁴ C in a sample decreases over time (t), its half-life being equal to 5730 years. The ¹⁴ C content is substantially constant from the extraction of the renewable raw materials, to the production of the olefin-based polymer derived from renewable resources used in the invention and even until the end of the use of the object comprising this polymer.

Therefore, the presence of ¹⁴ C in a material, and this, whatever the quantity, gives an indication of the origin of the molecules constituting it, namely that they come from renewable raw materials and not from fossil materials . The amount of ¹⁴ C in a material can be determined by one of the methods described in ASTM D6866-06 (Standard Test Methods for Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis). This standard contains three methods for measuring organic carbon derived from renewable raw materials, referred to in English as "biobased carbon". The proportions indicated for the olefin comprising from 6 to 9 carbon atoms and the polymer of the invention are preferably measured according to the mass spectrometry method or the liquid scintillation spectrometry method described in this standard, and most preferably by mass spectrometry. These measurement methods estimate the ratio of ¹⁴ C / ¹² C isotopes in the sample and compare it to a ratio of ¹⁴ C / ¹² C isotopes in a material of biological origin giving the 100% standard, in order to measure the percentage of organic carbon of the sample. Preferably, the olefin (a) used for the manufacture of the polymer according to the invention comprises a quantity of carbon derived from renewable raw materials greater than 20%, preferably greater than 50% by weight relative to the total mass of carbon olefin comprising from 6 to 9 carbon atoms. In other words, the olefin derived from renewable resources may comprise at least 0.24 10 ^-10 % by mass of ¹⁴ C, and preferably at least 0.6 10 ¹⁰ % by weight ¹⁴ C. Advantageously the amount of carbon derived from renewable raw materials is greater than 75%, preferably equal to 100% by weight relative to the total carbon mass of the olefin (a) comprising from 6 to 9 carbon atoms. Advantageously, the polymer according to the invention comprises a quantity of carbon derived from renewable raw materials greater than 20%, preferably greater than 50%, even more preferably greater than 75% and most preferably equal to 100% by weight relative to the mass. total carbon of the polymer.

According to the process of the invention, this renewable raw material is a fatty substance, for example a vegetable oil or an animal fat. A fatty substance comprises triglycerides having the following form: R '- COOCH ₂ R ² - COOCH R ³ - COOCH ₂

These triglycerides are R-COOH fatty acid triesters; the fatty substances thus comprise fatty acids in the ester form.

Vegetable oils are mainly present in various oleaginous plants such as sunflower, rapeseed, castor oil, lesquerella, olive, walnut, soy, palm, coriander, celery, dill, carrot, fennel, Limnanthes Alba (meadowfoam). Animal fats come from the terrestrial or marine animal world, and in the latter case, both in the form of fish, mammals and algae. This is in general fat from ruminants, fish such as cod or marine mammals.

Vegetable oils are preferably used as fatty substances. It is common to distinguish two types of fatty substances: saturated fatty substances, none of which contains unsaturated fatty acids C = C, and unsaturated fatty substances, of which at least one fatty acid of the fatty substance comprises a type C unsaturation = C. According to the process of the invention, at least one fatty acid of the fatty substance comprises a type unsaturation

C = C.

Advantageously, this fatty substance is a vegetable oil comprising fatty acids in ester form chosen from ricinoleic acid, palmitoleic acid, oleic acid, erucic acid, linoleic acid or linolenic acid. According to a preferred embodiment of the invention, this fatty substance is a vegetable oil comprising ricinoleic acid.

By way of illustration, the mass quantities of the various fatty acids included in the triglycerides of various vegetable oils or animal fats are presented in FIG.

Table 1. It is specified that this list of fatty acid is illustrative and that any type of vegetable oil or animal fat known to those skilled in the art can be used.

As fatty substance, mention may also be made of mustard seeds which comprise about 40% of erucic acid in ester form. The method of manufacturing the polymer according to the invention comprises the following steps:

A. treating said fatty substance to form an olefin (a) comprising a number of carbon atoms in the range of 6 to 9; B. polymerization of the constituent monomers of which at least one is the olefin (a).

According to the process of the invention, it is of course possible to carry out purification steps of the intermediate products or of the polymer according to the invention.

To carry out the manufacturing process according to the invention, fatty substances extracted from renewable resources are used. There are many methods to extract a fat from a plant or animal. These fats are commercially available. The oil can be extracted by first grinding the seeds to obtain a first part of the oil and a residue of crushed seeds; this step is commonly called "trituration". Preferably, a second part of the oil is extracted from the rest of the crushed seeds by a solvent, generally an alkane solvent, for example hexane.

Step A of the manufacturing process

To form the olefin (a) according to the process of the invention, a dehydration step is conducted in a reactor to form a mixture of alkene and water. This dehydration step can be carried out in the presence of a dehydration catalyst, for example based on α-alumina, which can be acidic or basic, in the presence of alcohols obtained from raw materials of renewable origin. The catalyst may be in the form of powder or granule. The amount of Si in the catalyst is preferably less than 500 ppm. According to a first version of the invention, a basic catalyst, for example a Barium-doped alumina, is used to further increase the selectivity of the dehydration. According to a second version of the invention, an acid catalyst is used to improve the yield of the reaction. An example of a catalyst suitable for the dehydration of these alcohols is in particular marketed by the company EUROSUPPORT under the trade name ESM 1 10 ^® . It is an undoped trilobal alumina containing little residual Na2 <0 (usually 0.04%). The temperature and / or the pressure are chosen inside the reactor so that the alcohol is in vaporized form. The dehydration reaction of the formed alcohol can be carried out for example in the temperature range of 250 to 400 ^° C. This dehydration can advantageously be carried out under partial vacuum, for example at a pressure of between 500 and 760 mmHg.

It is also possible to inject with the alcohol a coolant consisting of an inert product for dehydration, this inert product being gaseous under the conditions of the process. Examples include nitrogen, helium, argon, water, methane, propane, butane and other aliphatic and aromatic hydrocarbons. For example, it is possible to use from 0.05 to 10 moles of inert product per one mole of alcohol introduced and preferably from 0.15 to 3 moles. Preferably, the dehydration catalyst comprises at least one alumina chosen with a volume of all the pores included in the alumina greater than 0.9 ml / g, of which at least one of the pores has a maximum radius included in the range from 1 to 9 nm and at least one of the other pores has a maximum radius greater than 25 nm. These include eg PURAL ^® KRL catalyst produced by Sasol. Advantageously, a purification step of the olefin (a) obtained by the known techniques, for example by a distillation step, is carried out. When a saturated alcohol whose only alcohol function is alpha is dehydrated, a single isomer (an alpha-olefin) is obtained; when the saturated alcohol is not alpha, a mixture of two isomers is formed. In all cases, a lower number of isomers is obtained compared to the conventional cracking and steam cracking of fossil resources.

It is possible to carry out a hydrolysis or transesterification reaction of the fatty substance. During the hydrolysis or transesterification reaction of the fatty substance, fatty acids or fatty esters are formed with glycerol, respectively.

This reaction takes the following form, R ⁴ being H in the case of hydrolysis and an alkyl group in the case of transesterification: R '- COOCH ₂

R ² - COOCH + 3R ⁴ OH OR '- COOR ⁴ + R ² - COOR ⁴ + R ³ - COOR ⁴ + glycerol R ³ - COOCH ₂

Transesterification can be carried out with methanol or ethanol, preferably with methanol. Preferably, this transesterification is carried out in a basic medium, for example in the presence of sodium hydroxide, the amount of basic catalyst may be from 0.1 to 1% by weight of the reaction medium. It can be carried out by reacting the fatty substance in a stirred reactor in the presence of a excess alcohol (eg methanol), preferably with a basic catalyst (such as sodium methoxide or sodium hydroxide). This transesterification reaction is preferably carried out at a temperature of between 40 and 120 ^° C. In order to carry out the hydrolysis reaction, the fatty substance is preferably reacted in the presence of an excess of water, preferably with an acid catalyst. The hydrolysis may be carried out for example at a temperature of between 10 and 100 ^° C., preferably of 15 to 60 ^° C. and most preferably of 20 to 50 ^° C. Preferably, the reactor is continuously fed to maintain the molar ratio water / acid or alcohol / ester greater than or equal to 2/1, for example from 3/1 to 10/1. At the end of the reaction, glycerol is separated from the resulting mixture of fatty acids or fatty esters by decantation, and these acids or esters are washed to remove traces of glycerol. Advantageously, the products obtained are isolated, for example by distillation.

According to the process of the invention, the C = C type unsaturation of the fatty substance, the ester or the acid is cut off, this cleavage being carried out by a cracking reaction or by oxidative cleavage, for example ozonolysis.

The ozonolysis reaction (unbalanced), which has an ozonide intermediate (not shown), takes the following form:

R-CH = CH-R '+ 3 O ₃ RCOOH + RCHO + RCHOO + R'COOH + R'CHO + R'CHOO Carboxylic acids, aldehydes and peroxides are formed according to the conditions. An advantage of this oxidative cleavage process is that it is carried out at low temperature, which makes it possible to limit the costs related to the heat supplied to the reaction medium.

To carry out an ozonolysis reaction, the fatty substance, the acids or the esters are placed in a first phase in solution in an organic solvent. To put the reactor in ozonolysis condition, it is stirred in the presence of ozone. Any type of organic solvent, for example selected from esters, acids, alcohols or dimethylsulfoxide (DMSO), may be used for this reaction. Water can also be used as a solvent. Depending on the miscibility of the reactants with the solvent, the reaction medium will be composed of a single phase or an emulsion of one phase in another (this is the case, for example, for unsaturated esters in an aqueous solvent) . It is preferably carried out in DMSO or a solvent of the alcohol, methanol, ethanol, propanol, butanol, methoxyethanol, cyclohexanol or benzyl alcohol type; in the case where the ozonolysis is carried out on the fatty ester, it is advantageous to use the alcohol R-OH corresponding to this one. This reaction can be carried out at low temperature, for example in the temperature range between 20 ^° C. and 60 ^° C., preferably between 25 ° and 40 ^° C.. The ozonide is then formed.

To form the products of ozonolysis, a second phase is carried out either a hydrolysis reaction of the ozonide, or a reduction of the ozonide.

It is possible to carry out a hydrolysis reaction of the ozonide in basic catalysis (for example using concentrated sodium hydroxide) while maintaining the reaction medium in a low temperature ozonolysis condition. The final products are then formed. By performing a final ozonolysis step by acidifying the medium, a mixture of RCOOH and R'COOH acids is then obtained.

It is also possible, in a second embodiment, to reduce the ozonide as described in application FR0854708.

This reduction can be carried out with zinc in acetic acid, with hydrogenation in the presence of a hydrogenation catalyst (for example Pd) or with the aid of a reducing agent such as for example dimethylsulfide (DMS). . A mixture of aldehydes RCHO and R'CHO is obtained.

The preferred variant of this oxidative cleavage step is reductive ozonolysis which can be carried out in the presence of zinc metal, in powder form, or even preferably in the presence of DMS in DMSO; in fact, this DMS will be transformed during the reductive ozonolysis into DMSO, this DMSO being easily reusable.

Other methods are also described in GB810571, WO2007 / 039481, US6455715 and US2819279, or alternatively by Ackman et al. In Ozonolysis of unsoturoted fotty ocids: I. Ozonolysis of oleic ocid (Canadian Journal of Chemistry, Vol. 39, 1961, pp. 1956-1963). For example, if ozonolysis of linoleic acid or fatty substances containing linoic acid is carried out, one of the products is 1-hexanoic acid or hexanal. In the same way, pelargonic acid or nonanaldehyde is formed from oleic acid. The products obtained can advantageously be purified at the end of the oxidative cleavage step, for example by a distillation step.

To carry out a cracking reaction, the fatty substance, the ester or the acid is placed in the reactor and the cracking reaction is carried out by heating the reaction medium under pyrolysis conditions (for example under nitrogen), by selecting the conditions for example temperature and pH of the reaction solution to obtain the desired products. Optionally, cracking catalysts are used acids, such as crystallized aluminosilicate zeolites. The cracking temperature of the fatty substances can be in the range from 180 to 65O ⁰ C. Forms, according to the cracking conditions, carboxylic acids, aldehydes or saturated alcohols. For example, according to a first embodiment, cracking is carried out on a vegetable oil comprising ricinoleic acid in ester form, such as castor oil, in a basic medium, for example in the presence of sodium hydroxide, in a preferred temperature range. ranging from 180 to 300 ⁰ C to form octan-2-ol. This cracking step can optionally be carried out on ricinoleic acid or a ricinoleic acid ester obtained by a step of hydrolysis or transesterification of this vegetable oil. This cracking step is described for example in the documents US6392074 or US3671581.

According to a second preferred embodiment, the cracking reaction of a vegetable oil comprising ricinoleic acid in ester form, such as castor oil, is carried out by vaporizing it in the reactor in the presence of steam.

This cracking step can optionally be carried out by introducing, instead of the oil, ricinoleic acid or a ricinoleic acid ester, for example methyl ricinoleate obtained by transesterification of castor oil with methanol. This fatty acid or this fatty ester is obtained by a step of hydrolysis or transesterification of this vegetable oil. Preferably, the cracking reaction of castor oil or methyl ricinoleate is carried out.

The weight ratio of castor oil / water or alkyl ricinoleate / water is preferably between 1 and 3. The reaction is carried out at a temperature of between 450 and 650 ^° C., preferably between 450 and 575 ^° C., for example 500 ^° C. at 575 ^° C., generally for a period of 5 to 30 seconds. This cracking step is described for example in the book "Petrochemical Processes" by A. Chauvel et al. published by TECHNIP Publishing (1986) in the section devoted to the synthesis of 1-amino-1-undecanoic acid. Among the reaction products, heptaldehyde is obtained. The products obtained can advantageously be purified at the end of the cracking step, for example by a distillation step.

With regard to the hydrogenation reactions of the esters, acids or aldehydes, they take the following form:

R-COOR '+ 2H ₂ O R -CH ₂ OH + R'OH R-COOH + 2H ₂ ' R-CH ₂ OH + H ₂ O

R-CHO + H ₂ O R-CH ₂ OH These hydrogenation reactions can be carried out by reacting the ester, acid or aldehyde obtained from the fatty substance in the presence of excess dihydrogen on a catalyst comprising CuO and ZnO. Advantageously, the CuO / ZnO ratio is between 0.2 and 2. It is also possible to use catalysts based on copper chromite, optionally doped with barium and / or manganese. Preferably, this hydrogenation step is carried out at a temperature of 200 to 230 ^° C. and at a pressure of 3 to 5 MPa. The catalyst can be regenerated by contacting it with steam.

Preferably, a step is carried out for separating the alcohol formed, for example by a distillation step.

Here are several examples of step A of the process according to the invention: In a first example of the process according to the invention where n is equal to 6, the fatty substance comprises a linoleic acid ester in its C18: 2-delta form. 9,12 and step B comprises the following steps:

Hydrolysis of this fatty substance to obtain linoleic acid Cl 8: 2-delta 9,12;

• ozonolysis of linoleic acid;

• distillation of ozonolysis products to obtain hexanoic acid or hexanaldehyde; • hydrogenation of hexanoic acid or hexanaldehyde to form hexan-ol;

Dehydration of hexan-1-ol to form 1-hexene.

In a second example of the process according to the invention where n is equal to 7, the fatty substance is a vegetable oil comprising ricinoleic acid, preferably castor oil, and step A comprises:

A possible step of transesterification of this vegetable oil, for example by treatment with alcohol in a basic medium, preferably in the presence of sodium hydroxide, to obtain the alkyl ricinoleate; Cracking of this oil or of alkyl ricinoleate in the presence of steam under the pyrolysis conditions at a temperature ranging from 450 to 575 ^° C. for 5 to 30 seconds to form heptaldehyde;

• hydrogenation of heptaldehyde to form heptan-1-ol;

Dehydration of heptan-1-ol to form N-heptene. In a third example of the process according to the invention where n is equal to 8, the fatty substance is a vegetable oil comprising ricinoleic acid in ester form and step A comprises the following steps:

• possible transesterification of this vegetable oil by treatment with alcohol in a basic medium, preferably in the presence of sodium hydroxide, to obtain the alkyl ricinoleate;

Cracking of castor oil or of alkyl ricinoleate in basic medium under pyrolysis conditions at a temperature ranging from 180 to 300 ^° C. to form octan-2-ol; Dehydration of octan-2-ol to form a mixture comprising 1-octene and 2-octene.

In a fourth example of the process according to the invention where n is 9, the fatty substance is a vegetable oil which comprises oleic acid in ester form and step A comprises the following steps:

Transesterification of this vegetable oil to form an oleic acid ester;

Ozonolysis of the ester formed to form a pelargonic aldehyde or pelargonic acid; • Hydrogenation of pelargonic aldehyde or pelargonic acid to form nonan-1-ol;

Dehydration of nonan-1-ol to form 1-nonene as olefin (a).

Step B of the manufacturing process according to the invention

Advantageously, the olefin B polymerization step is a solution, fluidized bed, slurry or high pressure polymerization step. The olefin polymerization step (a), with possibly the olefin (b), may be carried out in different ways depending on the type of product to be manufactured. The olefin (a) is advantageously an alpha-olefin; its carbon number is chosen from olefins containing from 6 to 9 carbon atoms.

According to a mode of the invention, the constituent monomers of the polymer comprise, in addition to the olefin (a), a comonomer (b) which is ethylene or propylene. The comonomer (b) is preferably ethylene. The comonomer (b) is advantageously derived, at least in part, from renewable resources. To form ethylene or propylene, it is possible to use the teaching of the application FR0702781 which concerns the manufacture of carbon nanotubes. Their synthesis comprises the steps of: a) synthesis of alcohol (ethanol and / or propanol) by fermentation of at least one plant material comprising sugars; b) and dehydration of the alcohol obtained in a) to produce, in a first reactor, a mixture of alkene (ethylene in the case of ethanol and propylene in the case of propanol) and water: this step of Dehydration is generally carried out in the presence of a catalyst, which may in particular be based on silicalite for propanol or alumina for ethanol. The comonomer (b) can also be synthesized by biomass gasification by following the teaching of the application WO2008 / 067627.

The molar ratio (a) / ((a) + (b)) is advantageously in the range from 0.0001 to 0.5, preferably from 0.001 to 0.3. In general, the more the olefin content (a) is increased, the more the density of the polymer will tend to decrease.

In a particularly advantageous embodiment, the comonomer (b) is ethylene and the polymer is a polyethylene. In the case of polyethylene, one can have: • the high density polymer (HDPE) of density generally between 0.940 and 0.965 g / cm3, this polyethylene is distinguished by a low degree of branching and consequently by strong intermolecular forces and by a high tension force. The low branching is provided by the choice of catalyst and reaction conditions and the molar ratio (a) / ((a) + (b)) is generally less than 0.5%;

The medium density polymer (MDPE) with a density generally of between 0.925 and 0.940 g / cm 3, this polyethylene has good impact properties and the molar ratio (a) / ((a) + (b)) is generally lower than at 1%; • the low density polymer (LDPE) density generally between 0.915 and 0.935 g / cm3, this polymer has a high degree of branching chains (short and long). This polyethylene has a low tensile strength and increased ductility and generally does not include olefin (a); The linear low density polymer (LLDPE) with a density generally between 0.900 and 0.940 g / cm 3, this polymer is in a form substantially linear with a large number of short branches and the molar ratio (a) / ((a) + (b)) is generally between 0.1 and 3%; The very low density polymer (VLDPE) with a density generally of between 0.860 and 0.910 g / cm 3, this polymer is in a substantially linear form with a very large number of short branches and the molar ratio (a) / (( a) + (b)) is generally between 3 and 50%, preferably between 3% and 30%. Preferably, the polymer is chosen from HDPE, MDPE, PEDBL or PETBD.

For step B, it is possible to use known techniques for producing olefin-based polymers derived from fossil materials. The synthesis of the polymer is carried out according to three preferred methods: the solution method, the slurry method and the fluidized bed method (in the gaseous phase), especially for the synthesis of the copolymers based on (a) and (b). It is also possible to use the polymerization methods in high radical pressure (in an autoclave or tubular reactor).

In the case of solution, slurry and fluidized bed methods, a catalyst is used which may be Ziegler-Natta or metallocene or, to a lesser extent, Phillips type. The Ziegler-Natta catalysts conventionally consist of a halogenated derivative of a transition metal of group IV or V of the periodic table of the elements (titanium, vanadium) and of a alkyl compound of a metal of groups I to III . Metallocene catalysts are mono-site catalysts generally consisting of one atom of a metal that may be zirconium or titanium and two metal-linked cyclic alkyl molecules, more specifically, metallocene catalysts are usually composed of 2 linked cyclopentadiene rings. to metal. These catalysts are frequently used with aluminoxanes as cocatalyst or activators, preferably methylaluminoxane (MAO). Hafnium may also be used as the metal to which cyclopentadiene is attached. Other metallocenes may include IVA, VA, and VIA transition metals. Lanthanide metals can also be used.

The Phillips catalysts are obtained by depositing chromium oxide on a support (silica or silica aluminum) with a high specific surface area, of the order of 400 to 600 m ² / g. These catalysts are then reduced and activated at a very high temperature (400-800 ^° C.). The solution method can be implemented by introducing at least one olefin

(a) optionally with an olefin (b) in an autoclave reactor, in the presence of at least one solvent. The reactor can operate adiabatically or be provided with an external refrigerant. The catalyst used may be Phillips type, advantageously Ziegler-Natta, or metallocene.

The temperature of the reactor is generally between 150 and 300 ^° C. and the pressure between 3 and 20 MPa.

At the reactor outlet, the monomer-enriched gas is returned to the reactor inlet and the liquid stream comprising the polymer is treated to separate the polymer from the solvent. The polymer is then conducted in an extruder.

According to the fluidized bed or gas phase method, the reaction medium consists of catalyst particles around which the polymer is formed. The polymer produced is maintained in the solid phase, while the olefins (a) and optionally

(b) form the carrier gas of the fluidized bed. These olefins also make it possible to evacuate the heat of reaction and also the control of the molar mass.

The catalyst used may be Ziegler-Natta, metallocene or Phillips.

The temperature of the reactor is generally between 80 and 105 ^° C. and the pressure between 0.7 and 2 MPa.

For example, in the case of a polymer according to the invention based on ethylene and an olefin (a), the process is carried out in a vertical reactor, the ethylene is compressed to the required pressure and introduced at the inlet (lower part) of the reactor. The control of the ethylene pressure at the reactor inlet allows the control of the reaction pressure. The catalyst and optional cocatalyst and olefin (a) are introduced into the reactor.

At the outlet of the reactor, the gaseous mixture and the LLDPE are extracted from the fluidized bed and the pressure is then reduced in order to separate the polyethylene from the gases. The constituents of the gaseous mixture (ethylene and olefin (a)) are separated and possibly returned to the reactor. LLDPE (solid) is purged to remove any traces of ethylene and conducted in an extruder.

To manufacture PETBD, it is preferred to use a metallocene catalyst, for example using a solution or fluidized bed process.

The polymer may optionally be obtained from monomers other than olefin (a) and optionally olefin (b). The number-average molecular weight of the polymer may be greater than 2000 g / mol. This polymer or a composition comprising it can advantageously be used to manufacture any type of molded piece, blown, injected, a wire, a film, a bag, a bag, a multilayer structure, a container, a tank, a bottle, a sheath electric cable, a pipe, a tube, as impact modifier, softener or as a binder.

According to another version of the invention, the number-average molecular weight of the polymer is less than or equal to 2000 g / mol.

This polymer or a composition comprising it can be advantageously used for the manufacture of engine lubricants, textile lubricants, plasticizers or in household products.

According to one variant, the polymer obtained at the end of step B is then grafted.

As described hereinafter, the grafting of the polymer is carried out with at least one grafting monomer chosen from unsaturated carboxylic acids or their functional derivatives, unsaturated dicarboxylic acids having 4 to 10 carbon atoms and their functional derivatives, and alkyl esters containing C1-C8 or glycidyl ester derivatives of unsaturated carboxylic acids, metal salts of unsaturated carboxylic acids.

Glycidyl methacrylate or even more preferably maleic anhydride is preferred as a grafting monomer.

According to a particular variant of the graft polymer, it is possible to use maleic anhydride comprising carbon atoms of renewable origin. The maleic anhydride may be obtained according to the process described in application FR 0854896 of the Applicant, comprising the following steps: i) fermentation of renewable raw materials and optionally purification to produce a mixture comprising at least butanol; ii) oxidation of butanol to maleic anhydride at a temperature generally of between 300 and 600 ^° C., by means of a catalyst based on vanadium and / or molybdenum oxides; iii) isolating the maleic anhydride obtained at the end of step b). Conventionally, the microorganism used for the fermentation is a Clostridium, advantageously it will be Clostridium ocetobutylicum or one of its mutants. The renewable raw materials used are preferably those comprising sugars, cellulose or hemicellulose.

Preferably, this oxidation reaction of butanol is carried out in the presence of air or another gas comprising molecular oxygen, more preferably, the air or the other gas comprising molecular oxygen. is present in a large excess.

Various known methods can be used to graft a grafting monomer onto the polymer. This can be done by heating the polymer (alone or in mixture) at elevated temperature, from about 100 ⁰ C to about 300 ⁰ C, in the presence or absence of a solvent with or without a radical generator.

Suitable radical generators that can be used include peroxides, preferably peroxy esters, dialkyl peroxides, hydroperoxides or peroxyketals. These peroxides are marketed by ARKEMA under the trademark Luperox®. Examples of peroxy esters include t-butyl peroxy-2-ethylhexanoate (Luperox 26), t-butyl peroxyacetate (Luperox 7), t-amyl peroxyacetate (Luperox 555), tert-butyl perbenzoate (Luperox P ), t-amyl perbenzoate (Luperox TAP) and OO-t-butyl 1- (2-ethylhexyl) monoperoxycarbonate (Luperox TBEC). As dialkyl peroxides, mention may be made of 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane (Luperox 101), dicumyl peroxide (Luperox DC), alpha-alpha'-bis (t-butylperoxy) diisopropylbenzene (Luperox F40), di-t-butylperoxide (Luperox Dl), di-t-amylperoxide (Luperox DTA) and 2,5-dimethyl-2,5-di- (t-butylperoxy) hexyne-3 (Luperox 130). An example of a hydroperoxide is tert-butyl hydroperoxide (Luperox TBH70), for example 1,1-di- (t-butylperoxy) -3,3,5-trimethylcyclohexane (Luperox 231) can be used as the peroxyketal. ethly-3,3-di- (t-butylperoxybutyrate) (Luperox 233) or ethly-3,3-di- (t-amylperoxybutyrate) (Luperox 533).

The grafting reaction can then be carried out according to a batch process in solution or a continuous process with a melt mixing tool.

Another subject of the present invention is a composition comprising the polymer according to the invention and, in addition, at least one additional polymer different from the polymer according to the invention and / or additional additive making it possible to improve the properties of the final material. These additives include antioxidants, UV protection agents, so-called "processing" agents such as, for example, fatty amides, stearic acid and its salts, and fluorinated polymers (known to avoid defects in extrusion), anti-fogging agents, anti-blocking agents such as silica or talc, fillers such as calcium carbonate and nanofillers such as clays, coupling agents such as silanes, agents crosslinking agents such as peroxides, antistatic agents, nucleating agents, pigments, dyes, plasticizers, plasticizers, flame retardant additives, such as aluminum or magnesium hydroxides. These additives may be present for example in contents of between 10 ppm and 100,000 ppm by weight relative to the weight of the final copolymer. Some of these additives can be introduced into the composition in the form of masterbatches.

The additional polymer may be, for example, a polyolefin, particularly a polyolefin based on ethylene.

When the polymer has a number average molecular weight greater than 2000 g / mol, it may for example be used in inks as described in application US2007 / 0276060. In general, the polymer can also be used in the same manner and for the same applications as copolymers derived from fossil materials or compositions based on these copolymers already known. In the case where (a) is copolymerized with (b), according to the ratio (a) / ((a) + (b)), the polymer may for example be used to make yarn, films, bags, sachets, multilayer structures, containers, all types of molded parts, blown or injected such as tanks and flasks. It is also possible to use the polymer in the electrical field (for example to manufacture electric cable sheaths) or to manufacture pipes or tubes for conveying fluids. The polymer can also be used as impact modifier, softener to provide flexibility to a material in the polyolefin thermoplastic elastomers or to enter the binder composition.

When the polymer is an oligomer (average molecular weight less than or equal to 2000g / mol), it has good properties of low temperature fluidity, thermal stability, resistance to oxidation and hydrolysis, combined with low volatility at high temperature and good friction behavior; this oligomer is also slightly toxic and miscible with most mineral oils which makes it very suitable for use as a lubricant, for example in motor oils, compressor or hydraulic systems. It can also be used as a plasticizer or in household product compositions.

Example

An example of implementation of the method according to the invention is presented below. Polyethylene was prepared from ethylene and 1-heptene by carrying out steps A, B and C according to the process of the present application. It is specified that this implementation does not in any way constitute a limitation of the method according to the present invention.

From castor oil obtained by step A, a transesterification reaction of castor oil is carried out by reacting methanol on castor oil at 80 ^° C. catalyzed by sodium methoxide in a reactor. with tubular type stirring. 100 kg of castor oil are introduced into the reactor. The methanol / ester molar ratio is maintained at 6 during the reaction. After one hour, the methyl ricinoleate is separated from the glycerol and washed with water to remove the last traces of glycerin. The cracking of methyl ricinoleate is then carried out by vaporizing at 215 ^° C. in the reactor; it is mixed with steam at 600 ^° C. (ester / water ratio = 2) and reacted for 10 seconds at 500 ^° C.

After distillation, the heptanal is recovered and then the hydrogenation of the heptanal is carried out by introducing 10 kg of heptanal into a reactor to hydrogenate it. After separating N-heptanol from the other compounds, N-heptanol is injected to perform its dehydration in a tubular reactor having a diameter of 127 mm under vacuum (pressure of about 0.8 bar) containing a catalytic bed at a temperature of 345 ^° C. consisting of a layer of alumina ESMl 10 ^® from EUROSUPPORT, representing a volume of 12700 cm ³ and a mass of 6500 g, the hourly space velocity (ratio of the volume flow rate of heptanol to the catalyst volume) being 1 h - ¹ . The mixture of water and 1-heptene produced in the reactor is cooled in a heat exchanger, before being sent to a gas-liquid separator where N-heptene and water are separated.

An N-heptene purification step is carried out before carrying out the polymerization step C of the process. The latter is shown schematically in Figure 1. This implementation is carried out by means of the following device comprising a reactor R, and a gas recycling circuit comprising two C1 and C2 cyclone separators, two heat exchangers E1 and E2, a compressor Cp, a pump P. R reactor comprises a distribution plate (or distributor) D which delimits a lower zone which is a gas and liquid inlet zone and an upper zone

Where the fluidized bed is located.

The distributor D is a plate in which holes are arranged, this distributor is intended to homogenize the flow rate of the gases entering the reactor. According to this implementation, a mixture of ethylene and olefin (a) (1-heptene) is introduced via line 1, then via line 2 into the reactor where the fluidized bed polymerization is carried out.

The fluidized bed comprises the catalyst and preformed polymer particles, this bed is maintained in a fluidized state using a rising gas stream from the distributor D. The volume of the fluidized bed is kept constant by withdrawing the formed polyethylene by means of the discharge pipe 11.

The polymerization of the monomers is an exothermic reaction, the temperature inside the reactor is kept constant by controlling the temperature of the gas

(recycled) introduced into the reactor via line 10. The gas comprising the unreacted ethylene and 1-heptene molecules and a transfer agent (hydrogen) leaves the reactor and enters the recycling circuit via pipe 3. This gas is treated in the cyclone separator Cl to eliminate any fine particles of polyethylene that could have been entrained.

The treated gas is then introduced via line 4 into a first heat exchanger E1 where it is cooled.

The gas leaves the heat exchanger El via the pipe 5, enters a compressor

Cp, the fluid leaves via the pipe 6.

The fluid is cooled in a second heat exchanger E2.

Line 7 brings the fluid of the exchanger E2 to the cyclone separator C2. The gases are separated from the liquids in the cyclone separator C2, the liquids exit the cyclone separator C2 via the pipe 10 and are introduced into the reactor R, the gases exit the cyclone separator C2 through the pipe 8 enter the pump P and are introduced through line 9, then through line 2 into the reactor. The fluid composition at the reactor inlet observed over 3 successive passes was as follows:

The reaction was carried out under the following operating conditions

• pressure in the reactor: 25 bar

Temperature in the reactor: 9O ⁰ C

• gas velocity: 0.6 m / s

• height of the fluidized bed: 15 m

Fluid temperature at the inlet of the reactor: 40 ^° C.

According to these conditions, the yield obtained is for the various tests of about 120 kg / m ³ / h.

The polyethylene obtained has the following properties:

The flow index is measured according to ASTM standard D 1238 (190 ^° C., 2.16 kg). The density is measured according to ASTM D 1505.

Claims

claims

A process for producing a polymer, obtained from a fatty substance extracted from renewable resources and at least one fatty acid of the fatty substance comprising a C = C type unsaturation, comprising the following steps:

Optionally a hydrolysis or transesterification step of the fatty substance to form respectively fatty acids or fatty esters;

A cracking or oxidative cleavage reaction of the fatty substance, of the fatty acids or of the fatty esters to form saturated species having a number of carbons ranging from 6 to 9, which, according to the conditions, comprises an acid, ester, aldehyde or alcohol function ; An additional hydrogenation step when the function is aldehyde, acid or ester to form a saturated alcohol;

A dehydration step of the saturated alcohol obtained;

2. Method according to the preceding claim wherein the fatty substance is a vegetable oil comprising fatty acids in ester form chosen from ricinoleic acid, palmitoleic acid, oleic acid, linoleic acid, erucic acid or linolenic acid.

3. Method according to one of the preceding claims wherein n is equal to 7 or 8 characterized in that the fatty substance is a vegetable oil comprising ricinoleic acid in ester form.

4. Method according to one of the preceding claims wherein the transesterification reaction of the fatty substance is carried out with methanol.

5. Method according to one of the preceding claims wherein the transesterification reaction is carried out in basic medium, for example in the presence of sodium hydroxide.

6. Method according to one of the preceding claims wherein n is equal to 7 characterized in that step A comprises the following steps:

Cracking of a vegetable oil comprising ricinoleic acid in ester form, for example castor oil, or alkyl ricinoleate in the presence of steam under pyrolysis conditions at a temperature ranging from 450 to 575 ⁰ C for 5 to 30 seconds to form heptaldehyde;

The hydrogenation of heptaldehyde to form heptan-1-ol;

Dehydration of heptan-1-ol to form N-heptene as olefin (a).

7. Method according to one of claims 1 to 5 wherein n is equal to 8 characterized in that step A comprises the following steps:

Cracking of a vegetable oil comprising ricinoleic acid in ester form, for example castor oil, or of ricinoleate of alkyl in basic medium under the conditions of pyrolysis at a temperature ranging from 180 to 300 ^° C. to form octan-2-ol;

Dehydration of octan-2-ol to form a mixture comprising 1-octene and 2-octene.

8. Process according to one of claims 1 to 5 from a fatty substance comprising a linoleic acid ester in its C18: 2-delta form 9,12, in which n is equal to 6, characterized in that Step A comprises the following steps: hydrolysis of this fatty substance to obtain linoleic acid Cl 8: 2-delta 9,12;

• ozonolysis of linoleic acid;

• distillation of ozonolysis products to obtain hexanoic acid or hexanaldehyde;

• hydrogenation of hexanoic acid or hexanaldehyde to form hexan-ol;

Dehydration of hexan-1-ol to form 1-hexene.

9. Method according to one of claims 1 to 5 wherein n is equal to 9, from a vegetable oil comprising oleic acid in ester form characterized in that step B comprises the following steps: • trαnsesterification of this vegetable oil to form an oleic acid ester;

Dehydration of nonan-1-ol to form 1-nonene as olefin (a).

10. Method according to one of the preceding claims wherein the polymerization step B is in solution, fluidized bed slurry or high pressure.

1. Process according to one of the preceding claims, in which the constituent monomers of stage B additionally comprise a comonomer (b) of formula Cphbp in which p is an integer chosen in the range from 2 to 3, preferentially ethylene.

12. Method according to one of the preceding claims wherein the comonomer (b) is derived, at least in part, from renewable resources.

13. Polymer obtained by polymerization of constituent monomers of which at least one is an olefin (a) having a carbon number ranging from 6 to 9 made from renewable resources, obtainable by a process according to one of the claims. and the amount of carbon derived from renewable raw materials, measured according to ASTM D6866-06, is greater than 20%, preferably greater than 50% by weight relative to the total weight of carbon of the polymer.

14. Polymer according to the preceding claim, the constituent monomers further comprise an olefin (b) having a carbon number ranging from 2 to 3, preferably made from renewable resources.

15. Polymer according to one of claims 13 or 14, the molar ratio (a) / ((a) + (b)) is between 0.0001 and 0.3.