Cross-linkable compositions of functionalized polyolefin powders
FIELD: polymer materials.
SUBSTANCE: composition comprises polyolefin A, containing anhydride function and having viscosity at least 20 g/10 min measured at 190°C and loading 2,16 kg, and epoxy function-containing product B destined for cross-linking polyolefin A. Relative proportions of A and B are such that for each epoxy function there are from 0.1 to 1.5 anhydride functions. Composition can be used in slush molding process, in thermal molding of sheets, or in on-rod casting process.
EFFECT: increased flowability resistance and wear resistance.
6 cl, 1 tbl, 6 ex
The scope of the invention
The present invention relates to suitable for the cross-linkage compositions of powders polyolefin with functional groups that can be used in the way slush molding, or thermoforming sheets, or by casting the rod and, in particular, to compositions based on containing functional groups of the polyethylene.
Powders of polyvinyl chloride or polyolefins used to produce coatings with a method of forming at the free leakage of powder on hot form (hereinafter called the way slush molding). Slush molding is used for the manufacture of coatings for instrument panels, door panels and consoles in the field of automotive industry. The powder is introduced into contact with the hot form, using, in particular, the method is free of leakage. The melting of the powder forms a coating. These coatings are very soft to the touch and not have residual stresses that allows you to avoid ageing of the coating of the danger of cracking under the influence of the relaxation of residual stresses.
The dashboard of the cars are very often made of polyurethane and cover with PVC coating, obtained using the method slush molding. Polyvinyl chloride is used less and less because of the risk of pollution resulting from its combustion. In this regard, oznachaet the need to develop polyolefin coatings. In the past, have already been described coating of polypropylene, but these coatings are not sufficiently resistant to the high temperatures that may occur in the car in bright sunlight and Windows closed. The heat resistance of the coatings was measured on the basis of fluidity when heated.
In the patent FR 2721319 described composition powder for slush molding on the basis of polypropylene and ethylene-propylene rubber (EPR). The coating does not have good resistance to creep.
Brief description of the invention
In the present work found a composition of powders of polyolefins suitable for use in the method slush molding, thermoforming sheets or for casting the rod and which can be subjected to cross-linking, resulting in achieving high stability in respect of yield strength and durability. Thus, the present invention relates able to be crosslinked composition powder of polyolefin containing functional groups, which includes:
- containing functional groups of the polyolefin (A)having a MFI of at least 20 (190°C, 2,16 kg) and containing anhydrite and/or epoxy functional group;
- the product (In)designed for crosslinking (A);
while the composition has a grain size distribution from 100 to 400 μis.
In accordance with the first embodiment of the invention (A) is selected from copolymers of ethylene with an anhydride of an unsaturated carboxylic acid, and (C) chosen from copolymers of ethylene with unsaturated epoxide.
In accordance with the second embodiment of the invention (A) is selected from copolymers of ethylene with an anhydride of an unsaturated carboxylic acid, and (C) is selected from polyamines, adsorbed on the zeolite.
In accordance with a third embodiment of the invention (A) is selected from copolymers of ethylene with unsaturated epoxide, and (C) is selected from polyamines, adsorbed on the zeolite.
In the way a slush molding composition according to the invention is converted into the coating in contact with the form. Blending occurs at a temperature higher than the melting point (A)when it is produced in that period of time when the coating is in the form that occurs, for example, in the three embodiments of the invention. Blending occurs at a temperature ranging from room temperature to the softening temperature (A) in the case when the merging is initiated later by the process of diffusion of moisture through the coating, as, for example, in the second and third embodiments of the invention, if resorted to displace moisture amine of the zeolite after the formation of the coating is.
A detailed description of the invention
Relative to the first variant embodiment of the invention.
The copolymers (A) may be polyethylene, on which are grafted anhydride of unsaturated carboxylic acid, or copolymers of ethylene with unsaturated carboxylic anhydride of the acid, which receive, for example, by radical polymerization.
The anhydride of the unsaturated carboxylic acid may be selected from, for example, anhydrides of the following acids: maleic, Takanawa, Tarakanova, allinternal, cyclohex-4-ene-1,2-dicarboxylic, 4-metalenclosed-4-ene-1,2-dicarboxylic, bicyclo(2,2,1)hept-5-ene-2,3-dicarboxylic and x-methylbicyclo-(2,2,1)hept-5-ene-2,2-dicarboxylic. Mostly use of maleic anhydride. Without leaving the scope of the invention, it is possible the entire anhydride or part to replace the unsaturated carboxylic acid such as (meth)acrylic acid.
As for polyethylene, which grafted anhydride of unsaturated carboxylic acid, in this case refers to polyethylene Homo - or copolymers.
As comonomers can be named:
- alpha-olefins, mainly containing from 3 to 30 carbon atoms; and as examples of alpha-olefins can be called propylene, 1-butene, 1-penten, 3-methyl-1-butene, 1-hexene, 4-methyl-1-penten, Z-methyl-1-penten, 1-octene, 1-mission 1-dokusen, 1 tetracosane,1 hexacosane, 1 octacosane and 1 triacetin; these alpha-olefins may be used individually or in mixture of two or more;
- esters of unsaturated carboxylic acids, such as alkyl(meth)acrylates, alkali which can have up to 24 carbon atoms; examples of alkylacrylate or alkylmethacrylamide are, in particular, methyl methacrylate, acrylate, n-butyl acrylate, isobutylamine, 2-ethyl hexyl acrylate;
vinyl esters of unsaturated carboxylic acids, such as vinyl acetate or finalproject;
- diene, such as 1,4-hexadiene;
the polyethylene may contain more of the above-mentioned comonomers.
Polyethylene, which can be a mixture of several polymers, mainly contains at least 50 and preferably 75 mol.% of ethylene. Its density is in the range from 0.86 to 0.98 g/cm3. MFI (viscosity index at 190°C, 2,16 kg) lies mainly in the range from 20 to 1000 g/10 minutes
As an example, polyethylenes can be called:
- low density polyethylene (LDPE)
- high density polyethylene (HDPE)
linear low density polyethylene (LLDPE)
- polyethylene, very low density (VLDPE)
the polyethylene obtained by metallocene catalysis, i.e. the polymers obtained by copolymerization of ethylene with an alpha olefin, such as propylene, butene, g is Xen or octene, in the presence of one catalyst consisting, typically, of a single atom of zirconium or titanium, and two associated with metal cycloalkyl molecules. More specifically, the metallocene catalysts are usually a connection of two related metal cyclopentadienide cycles. These catalysts are often used with alumoxane as socialization or activators, mainly with methylalumoxane (MAO). Hafnium can also be used as a metal, on which is fixed the cyclopentadiene. Other metallocene may include transition metals of groups IVA, VA and VIA. Can also be used metals of the series of lanthanides.
elastomers EPR (ethylene-propylene-rubber)
elastomers EPDM (ethylene-propylene-diene)
- mixtures of polyethylene with one EPR EPDM or one
- copolymers, ethylene-alkyl(meth)acrylate, which may contain up to 60 wt.% (meth)acrylate, mostly from 2 to 40 wt.%.
Grafting is an operation which is known in itself.
As for the copolymers of ethylene with unsaturated carboxylic anhydride of the acid, i.e. copolymers, in which the anhydride of unsaturated carboxylic acid is unvaccinated, in this case we are talking about the copolymers of ethylene anhydride of unsaturated carboxylic acids and, possibly, another monomer that can betweren of comonomers, as mentioned above for the copolymers of ethylene intended for vaccinations.
Mostly use the copolymers of ethylene-maleic anhydride and ethylene-alkyl(meth)acrylate-maleic anhydride. These copolymers contain from 0.2 to 10 wt.% maleic anhydride and from 0 to 40 wt.% and preferably from 5 to 40 wt.% the alkyl(meth)acrylate. Their MFI is in the range from 20 to 100 (190°C, 2,16 kg). The alkyl(meth)acrylates as described above. The melting temperature is in the range from 80 to 120°C.
A commercially available copolymer (A) is the product of a radical polymerization at a pressure of from 200 to 2500 bar. It goes on sale in the form of granules. It can be turned into a powder using microgranulate, for example, using the method of underwater cutting company GALA (Virginie, USA) or cryogenic grinding.
As for the copolymers of ethylene with unsaturated epoxide (In), they can be obtained by copolymerization of ethylene and an unsaturated epoxide or by grafting an unsaturated epoxide on the polyethylene. The vaccine can be produced in phase solvent or in the molten polyethylene in the presence of peroxide. The methods used vaccinations are in themselves known. As for the copolymerization of ethylene with unsaturated epoxide, can be used the so-called methods of radical polymerization is usually conducted under pressure is from 200 to 2500 bar.
As unsaturated epoxides can be named:
complex and simple aliphatic esters of glycidol, such as allylglycidyl ether, vinylpyridine ether, glycidylether and-itaconate, glycidyl(meth)acrylate and
complex and simple alicyclic esters of glycidol, such as 2-cyclohexen-1-glycidyloxy ether, cyclohexene-4,5-diglycidylether, cyclohexen-4-glycidyloxy, 5-norbornene-2-methyl-2-glycidyloxy and endo-CIS-bicyclo(2,2,1)-5-hepten-2,3-digitalliteracy.
As for vaccinations, a copolymer obtained by grafting polyethylene, homopolymer or copolymer as described for (A), except that instead of anhydride grafted epoxide. As for the copolymerization, in this case also there is a similarity with (A), except for using the epoxide. In this case, as in case (A), can be used other comonomers.
The product (C) is predominantly a copolymer of ethylene/alkyl(meth)acrylate/unsaturated epoxide. Preferably the content up to 40 wt.% the alkyl(meth)acrylate, more preferably from 5 to 40 wt.%, and up to 10% of an unsaturated epoxide, more preferably from 0.1 to 8%.
The epoxide is mostly glycidyl(meth)acrylate.
The alkyl(meth)acrylate is chosen mainly from methyl(meth)acrylate, ethyl acrylate, n-butyl acrylate, isobutylacetate 2-ethylhexyl acrylate. The amount of alkyl(meth)acrylate is preferably from 20 to 35%. MFI is preferably from 5 to 100 (g/10 min at 190°and a load of 2.16 kg), melting point ranges from 60 to 110°C. This copolymer can be obtained by radical polymerization of monomers. Transformation into a powder is produced, as in the case of (A).
Without leaving the scope of the invention, the composition may contain multiple polymers (a) and/or more polymers (B). (This applies to all variants of the embodiment of the invention.)
As for the proportions (a) and (b), it is preferable that they were such. to provide from 0.1 to 1.5 (mainly from 0.2 to 0/6) anhydrite functions one epoxy function. It is preferable to use a catalyst, i.e. a product that can accelerate the reaction between anhydrous functions and epoxy functions. This catalyst starts to act after melting (a) and (b), which must be close. The amount of catalyst can be easily determined by the expert, because the reaction between anhydrous and epoxy functions themselves known. The stitching is mainly carried out by heating the shape to a temperature higher than the melting point (A).
Of the compounds capable of accelerating the reaction between the epoxy function is contained in (In), and anhydrite by the function containing the action scene in (A), can be, in particular, are:
- tertiary amines, such as dimethylbenzylamine, dimethylstyrene, N-butylparaben, N,N-dimethylcyclohexylamine, benzyldimethylamine, pyridine, 4-(dimethylamino)pyridine, 1-Mei, tetramethyldisilazane, N,N-dimethylpiperazine, N,N,N',N'-tetramethyl-1,6-diaminohexane, a mixture of tertiary amines containing from 16 to 18 carbon atoms and is known as dimethylsulfone,
- tertiary phosphines, such as triphenylphosphine,
- alkyldiethanolamine zinc,
acids, such as polymers of type Lukalen (ternary copolymer of ethylene/butyl acrylate/acrylic acid),
- magnesium salt such as a mixture of 65% of the salt of stearic acid and 35% of the salt of palmitic acid.
Relative to the second variant embodiment of the invention.
Polyethylene with functional groups (A) was already described for the first variant. (B) is a polyamine adsorbed on the zeolite, which under the influence of temperature increase is desorbed and staples (A). It is enough to choose such a pair polyamine - zeolite to desorption occurred at a temperature at least equal to the melting point (A). Desorption stimulates water or moisture, and why it is recommended to avoid the occurrence of crosslinking during storage to add to the zeolite with adsorbed polyamino another zeolite, which is capable of also biavati moisture. This method of crosslinking a polymer containing groups, carboxylic acid anhydride, using zeolites, releasing polyamine under the influence of temperature or moisture, was described in the patent US 5792816, the content of which is incorporated into the present application.
As an example polyamine can be named: Ethylenediamine, diaminopropane, diaminobutane, diaminopentane, diaminohexane, isomers called amines, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, Diethylenetriamine, Triethylenetetramine, Tetraethylenepentamine, N-amino-ethyl-3-aminopropyltriethoxysilane, triaminopyrimidine, piperazine, AMINOETHYLPIPERAZINE, diaminopimelate, xylylenediamine, ISOPHORONEDIAMINE, 3,3'-dimethyl-4,4'-diaminocyclohexane, 1,4-diaminobenzanilide. Part polyamine may be replaced by polyols or aminoalcohols, such as ethylene glycol, propylene glycol, triethylene glycol, dipropyleneglycol, butanediol, neopentylglycol, cyclohexanedimethanol, hydroquinone-bis-hydroxyl-ether, triethanolamine, methyldiethanolamine, Tripropylamine, N,N-di(2-hydroxy-ethyl)aniline, ethanolamine, diethanolamine, propanolamine, dipropylamine and N-hydroxyacetanilide. As zeolites, mainly those in which the pore size is from 0.3 to 1.5 nm, and preferably zeolite from among the following four (specified pore size):0,38 nm, denoted as type 4A,
of 0.44 nm, denoted as type 5A,
0.8 nm, denoted as type 10X,
0,84 nm, denoted as type I.
All of these zeolites are available with the grading of the order of 20 to 50 μm Along with polyamines in the zeolite can be adsorbed to the catalyst reaction of the anhydride with the amine. Below are various examples of temperature desorption:
|Zeolite||Amin||The temperature of desorption, °|
After the formation of the coating composition can be carried out immediately by heating to a temperature above the melting temperature or later, after removing the coating from the mold, by diffusion of moisture from the environment in which the temperature range from room temperature up to the softening temperature (A).
Relative to the third variant embodiment of the invention.
He is like the second option with the difference that instead of the copolymer of ethylene and carboxylic acid anhydride used is a copolymer of ethylene epoxide and named the copolymer is already described as the polymer (B) for the first variant, it is only necessary that its MFI value was not less than 20.
The crosslinking reaction is carried out in a single or twin screw extruder, in which the polyolefin is introduced from the feed hopper, for example, in the form of granules. In the first zone of the extruder, the polyolefin is heated to melting, and in the second zone in the mass of molten polyolefin injected reagents.
The radical type initiators can be selected from among the peroxides, nakilat, esters of nagkalat peroxide and acetals. They are used in quantities of from 0.01 to 0.5% by weight of grafted polyolefins.
The composition of the invention may also contain protivozmeinaya agents such as Aerosil R972, pseudoviruses agents, such as ethylene-bis-stearamide, agents that facilitate the retrieval of forms, such as calcium stearate or magnesium stearate, and other ingredients such as increasing the adhesiveness of the resin, for example, Regalite resin R1115.
The composition of the invention may also contain technological stabilizers (= processing stabilizers, such as Irgafos 168, DDPP, P-EPQ, TNPP, TPP, 800 PS, PS 802, antioxidants, such as the Irganox 1010, 245, 259, 565, 1035, 1076, 1098, 1135, 1141, 1330, 1425, 3052, 3114, 5057, M, a mixture of antioxidants and process stabilizers, such as Irganos B225, UV filters, such as kit and Tinuvin company CIBA Chimassorb.
The composition of the invention may also contain fillers and coloring pigments such as carbon black and TiO2.
They may also contain deodorizing agents, such as activated carbon: 33 for example, CXV (SES), undecylenoyl acid, ethyl ester undecylenate acid, undecylenic calcium and undecylenate zinc, cyclodextrin, zeolites, such as Flavith, and odorants.
After the formation of the coating by melting a mixture of powders (A)+(b) on hot form, remove the excess of nerasplativshegosya powder, after which you can continue or initiate stitching, bear form in a furnace at a temperature in the range from 200 to 350°C for a time from 10 seconds to 10 minutes After this form is cooled and separated floor. In the second and third embodiments of the invention can also first to separate the coating from the mold and then make the stitching in the presence of moisture.
The composition according to the invention allow to obtain very soft to the touch cover with a shore hardness below 90 without the use of liquid plasticizers which do not exhibit high-temperature yield strength. Preferred the following characteristics of these coatings:
thickness in the range from 0.6 to 1.2 mm
- tensile strength of not less than 5 MPa
- elongation at break of at least 300%
- aging after 500 hours at 100°expressed in change of elongation of not more than 40%
- aging after 250 hours at 120°expressed in change of elongation at break, not more than 50%
- aging after 250 hours at 120°expressed in voltage changing at break of not more than 10%
- elongation after deformation at 140°under the load of 0.5 bar is not more than 30%
- turbidity (Fogging DIN 75201, 3 hours at 100° (C): any precipitate (measurement of migration of phthalates)
- abrasive scratch and abrasion resistance for 30 min in accordance with the rules
- glitter in accordance with the rules
- the resistance (22 hours at 100° (C) in accordance with the rules.
Unless otherwise noted, the composition of products (% of acrylate and the like) and the composition of the powders according to the invention are expressed by weight.
Used the following products:
LOTADER®8900 - copolymer ethylene/methyl acrylate/glycidyl-methacrylate (GMA) with 28% of acrylate and 7.8% GMA, MFI 6
LOTADER®6600 - copolymer ethylene/acrylate/maleic anhydride (MAN) with 27.5% of acrylate and 2.9% MAN, MFI equals 40
LOTADER®7500 - copolymer ethylene/acrylate/maleic anhydride (MAN) with 20% acrylate and 3.0% MAN, MFI equal to 70
LOTADER®AX 8999 - copolymer ethylene/butyl acrylate/glycidylmethacrylate (GMA) with 28% acre is LVL and 1% GMA, MFI is 70
XX 1275 - catalyst, dimethylsulfate (DMS) in the form of 3%of the master mix in the copolymer of ethylene/butyl acrylate/IAS 32% acrylate and 3% MAN, MFI equal to 7
LUCALEN A3110M - copolymer ethylene/butyl acrylate/acrylic acid with 8% of acrylate and 4% acrylic acid, MFI equal to 6-8 (190°C, 2,16 kg)
IRGANOX 225 1: 1 Irganox 1010/Irgafos 168
RESIN adhesive - REGALITE R1125
MM - carbon black
MAGNESIUM STEARATE is a mixture with 65% of the salt of stearic acid and 25% salt of palmitic acid
AEROSIL R972 (Degussa)
ACTIVATED carbon 33 and CXV (SES).
Various of the above components were crushed into powder with granules 200 μm using cryogenic grinding.
Were prepared with different compositions according to the invention by mixing the components in a powder mixer. Were made flooring using method slush molding. The form was heated to a temperature of 250°in the furnace. After that is removed from the furnace uniform was covered with excess powder used in the composition. After 10 seconds prespensis powder was removed by inverting the shape. The form again for 3 min was heated in an oven at 250°C, then cooled in cold water. Then the coating was separated from the form. Compositions and properties are listed in the following table 1.
Examples 5 and 6
Example 5 relates to the black floor, and example 6 on the grey floor. In these examples, achieved the best is e, than in examples 1-4, the results in relation to abrasive wear, mechanical properties and toxicity (no dimethylsulfide), better resistance to thermal ageing (antioxidants) and a weaker smell (activated carbon).
Preparation of the powder, which is the same for all compositions, consists of several stages.
1. The compounding of the composition on the basis of Lotader 7500 (composition a) and Lotader 8900 (composition) (example 5)
The following compositions were compounded on a twin-screw LEISTRITZ extruder with degassing at a temperature of 160°and compounds In compounded on a twin-screw LEISTRITZ extruder with degassing at a temperature of 180°C.
|Example 5 (black)||Composition (parts)||The composition (in parts)|
|Resin and REGALITE R1125||2,0||2,0|
|Coal soot MM||1,0||1,0|
|Lucalen M 3110||-||28,0|
|Activated charcoal 3S||1,0||1,0|
|The asset is qualified coal CXV||1,0||1,0|
2. A dry mixture of granules of the two components in specific proportions
Granules a and b were mixed with formation of a mixture with a mass ratio B/A=1,575
3. Preparation of powder by cryogenic milling and supplementation
The compositions were then subjected to cryogenic grinding into powder with granules 200 μm, then there comes to them in a high-speed mixer were added 2% of magnesium stearate and 0.6% silica AEROSIL.
4. slush molding
The form was processed at 100°With an agent that facilitates the extraction of shape, progulivali 20 min at 120° (Chem-Trend S.A. Mono Coat MC-708A) and heated in a furnace to a temperature of 250-350°C. then removed from the furnace uniform was covered with excess powder used in the composition. After 10 seconds prespensis powder was removed by inverting the shape. The form again within 1-5 min was heated in an oven at 250-300°C, then cooled in cold water. Then the coating was separated from the form.
Components and properties of the compositions of examples 5 and 6 below:
|Connection||Example 5 (black) (parts)||Example 6 (grey) (parts)|
|Lucalen M 3110||10,8||the 10.1|
|Resin and REGALITE R1125||2||2|
|Activated charcoal 3S||1,0||1,0|
|Activated carbon CXV||1,0||1,0|
|Coal soot MM||1||0,3|
|Added (dry mix)|
|Aerosil R 972||0,6||0,6|
|Stress at break (MPa)||>6||>6|
|Elongation at break (%)||>300||>300|
|Creep 0.5 b (min), 140°||>30||>30|
|The change in elongation at break after aging (250 h at 120° (C) (%)||<50||<50|
|The change in the voltage at break after aging (250 h at 120° (C) (%)||<10||<10|
|Fogging DIN 75201 (3 h at 100°)||Nick is someone sediment||Any precipitate|
1. Suitable for crosslinking the composition of the powder of polyolefin with functional groups used in the method of forming at the free leakage of powder on hot form (method slush molding), characterized in that it includes containing functional groups of the polyolefin (A)having a viscosity index MFI of at least 20 g/10 min (measured at 190°and under the pressure of 2.16 kg according to ASTM D 1238) and containing anhydrite functional group; the product (In)designed for crosslinking (A)containing epoxy group, and the relative content (And and (C) such that one epoxy functional group is from 0.1 to 1.5 anhydrite functional groups;
this composition has a grain size distribution from 100 to 400 microns.
2. The composition according to claim 1, characterized in that (A) is selected from copolymers of ethylene with an anhydride of an unsaturated carboxylic acid, and (C) chosen from copolymers of ethylene with unsaturated epoxide.
3. The composition according to claim 2, characterized in that (A) is selected from copolymers of ethylene-alkyl(meth)acrylate-maleic anhydride, which contain from 0.2 to 10 wt.% maleic anhydride and from 5 to 40 wt.% the alkyl(meth)acrylate.
4. The composition according to claim 2 or 3, characterized in that the product (B) is mainly what polimeros ethylene, the alkyl(meth)acrylate/unsaturated epoxide, which can contain up to 40 wt.% the alkyl(meth)acrylate and up to 10 wt.% unsaturated epoxide.
5. Composition according to any one of the preceding paragraphs, characterized in that it additionally contains a catalyst capable of accelerating the reaction between anhydrous and epoxy functional groups selected from tertiary amines, such as dimethylsulfone, tertiary phosphines, such as triphenylphosphine, alkyldiethanolamine zinc, acids, such as ternary copolymers, ethylene/butyl acrylate/acrylic acid, or salts of magnesium.
6. A method of manufacturing a product molded using the method slush molding, such as coverage of instrument panels of cars, including the melting of the composition according to any one of the preceding paragraphs, followed by cross-linking.
< / BR>where a 98,0-to 98.4 mol