NZ216100A - Thermoplastic compositions containing ethylene polymer and ethylene-maleic anhydride copolymer - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £16100 216100 Priority Date(s): Complete Specification Filed: Chss: . 7/ofa 2& 6 fc "' Publication Date: . ...3 0 MAY 1999 P.O. Journal, Nc: .

NO DRAWINGS PATENTS FORM NO: 5 PATENTS ACT 1953 COMPLETE SPECIFICATION "THERMOPLASTIC COMPOSITION COMPRISING A COPOLYMER BASED ON ETHYLENE AND MALEIC ANHYDRIDE, AND ARTICLES OBTAINED THEREFROM" WE, SOCIETE CHIMIQUE DES CHARBONNAGES S.A. of Tour Aurore Place des Reflets F-92080 Paris La Defense Cedex 5, France, a company organised and existing under the laws of France, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (Followed by page la) 2 16100 - lo - The present invention relates to thermoplastic compositions comprising a copolymer based on ethylene and maleic anhydride, intended especially for the manufacture of films having good adhesive properties. These compositions may also contain mineral fillings and may be used for making industrial articles which have an improved impact strength.

A first object of the present invention is a thermoplastic composition comprising, per 100 parts by weight, from 1 to 93 parts by weight of at least one polymer or copolymer (A) based on ethylene having a density lying between 0.905 and 0.945, characterized in that it additionally comprises from 7 to 99 parts by weight of at least one copolymer (B) based on ethylene and maleic anhydride.

"Polymer or copolymer (A) based on ethylene" is to be understood as a homopolymer of ethylene obtained by free radical polymerization, or indeed a copolymer of ethylene and at least one a-olefin having at least 3 carbon atoms, obtained in the presence of catalysts of the Ziegler type, or again a free-radical copolymer of ethylene and small quantities of at least one polar comonomer such as, especially, vinyl acetate, the alkyl (meth)acrylates wherein the alkyl group has from 1 to 6 carbon atoms, or carbon monoxide. Homopo 1 yiners or copolymers obtained by the free radical route generally have a density lying between 0.910 and 0.935. The degree of crystal 1inity of . r-,,v;v J ti 216100 polymer (A) is advantageously at least equal to 30X, especially from the standpoint of obtaining a composition having a satisfactory temperature stability.

The copolymer (8) may be obtained by direct copolymer-05 ization of ethylene and maleic anhydride, for example under high pressure and at high temper ature, or a 11ernative1y by grafting maleic anhydride onto polyethylene by any known method. It may further comprise groups derived from at least one ester of (meth)acrylic acid. In that case it may 10 be obtained by terpolymerization. for example under the i 3 conditions described in the documents FR-A-2 498 609, { FR-A-2 569 411 and FR-A-2 569 412, or further by grafting I maleic anhydride onto a copolymer of ethylene and of at least one ester of (meth)acryl ic acid. Such a copolymer 1 15 (B) advantageously comprises: from 83 to 98.7 mole percent of groups derived from ethylene, from 1 to 14 mole percent of groups derived from at least , one ester of (meth)acrylic acid, and ■ 20 from 0.3 to 3 mole percent of groups derived from maleic I anhydride. i ; The fluidity index of copolymer (B), measured under the I j standard conditions (190*C, sample of 2.16 kg) of the ASTM j 1238 standard, advantageously lies between 0.5 and j 25 200 dg/m i n.

Among the compositions according to the invention, those which comprise from 67 to 93 parts of polymer (A) and from 7 to 33 parts of copolymer (B) per 100 parts by weight, may further comprise at least one mineral filling to the extent 30 of up to 100 parts by weight per 100 parts by weight of the mixture of the polymers (A) and (B). This filling may be chosen especially from glass fibres, glass beads, mica, talc, clays, aluminates and silicates, for example those of calcium, alumina, alumina hydrate, carbon black, carbon or 35 boron fibres, asbestos, the oxide, hydroxide, carbonate and < ' L ■-> :i - 3 sulfate of magnesium or calcium, the oxides of iron, antimony, zinc, titanium dioxide, barium sulfate, benton-ite. diatomaceous earth, kaolin, silica, quartz, feldspar.

Among the compositions of the invention, those which 05 comprise from 1 to 67 parts by weight of polymer (A) and from 33 to 99 parts by weight of copolymer (B) per 100 parts by weight, are more especially intended for conversion into films. ■* For obtaining compositions having a range of acceptable 10 properties, the ratio of the standard fluidity index of the copolymer (8) to the standard fluidity index of the polymer (A) advantagously lies between 1 and 400.

The compositions according to the invention may be obtained according to a method chosen from: simultaneous mixing by any known means, especially in a kneading machine or an extruder, of polymers (A) and (B) and, optionally, the mineral filling; mixing a master batch of any two constituents of the composition, when the latter contains a mineral filling, 20 with the third constituent of the composition; when the composition includes a mineral filling, mixing of the polymer (A) and of the mineral filling previously coated with the copolymer (B), coating having been effected by introducing the filling into a solution of copolymer 25 (B), and then evaporating the solvent. Suitable solutions of copolymer (8) are obtained when the solvent is chosen from among the aliphatic, eye 1oa 1iphatic and aromatic hydrocarbons having from 5 to 12 carbon atoms, the ketones, the chlorinated hydrocarbons, the acetates and ethers of 30 polyols, and when the concentration of the copolymer (B) in the solvent does not exceed 153! by weight.

A second object of the invention is industrial articles containing at least one product obtained by conversion of a composition as described above. We may be principally e 216100 : concerned with films having adhesive properties (in this | case the fluidity index of the copolymer (B) will be chosen ; for preference between 0.05 and 30 dg/tnin) or again with moulded filled articles having an improved impact strength 05 which makes them especially interesting for all applications where that quality is required, especially in the automobile sector and for the manufacture of household and industrial articles.

^ Thanks to the noteworthy dimensional stability of the compositions according to the invention, films obtained by extrusion-b1owing of said compositions (of thickness generally lying between 15 and 200 ^im) may be used for producing laminates which have to withstand repeated v exposure to temperatures lying for example between 110* and i. | 15 130*C. They can be submitted to after-treatments, for ] example of the Corona type.

They may likewise form part of the constitution of articles of complex structure such as multi-layer films obtained by coextrusion by means of annular nozzles or plates, the 20 other layer(s) of such films consisting for example of a film of thermoplastic material such as low density free-radical polyethylene, high density polyethylene, poly-propylene, a polyamide or a copolymer of ethylene and hydrolyzed vinyl acetate.

The non-limiting examples which follow are given in order ■O to illustrate the invention. The standards used for measuring the properties of products employed or obtained are as follows: the ASTM D 1238-73 standard for the standard fluidity index measured at 190'C under 2.16 kg and expressed in dg/min; w! the ISO R 179 standard for the Charpy impact resistance o expressed in kJ/m and measured, with the immediately following exceptions, on a non-grooved test piece of the dimensions 4 x 6 x 50 mm^. 2 16100 - 5 Examples 1 to 5 Compositions are prepared by hot kneading of: x parts by weight of (A j) an ethylene/butyl acrylate copolymer containing 0.44 mole percent of butyl acrylate, 05 having a density of 0.926 and a standard fluidity index of 0.18 dg/m in: (100-x) parts by weight of (B) a terpolymer containing 92.; mole percent of groups derived from ethylene, 6.7 mole percent of groups derived from ethyl acrylate and 1 mole 10 percent of groups derived from maleic anhydride, having a standard fluidity index of 20 dg/min.

The characteristics of the compositions obtained are shown in table I. The Vicat temperature is measured according to the ASTM 0 1525 standard and expressed in degrees Celsius. 15 SO is the dimensional stability measured at 115°C according to the ASTM D 1204 standard and expressed in %. RR is the breaking strain expressed in MPa and AR is the elongation at break expressed in X, these two quantities being determined according to the ASTM 0 638 standard. TSC is 20 the critical surface tension expressed in dynes/cm and determined according to the ASTM D 2578 standard.

Examples 1 and 5 are comparative examples.

TABLE I I Example | 1 1 1 ? 1 1 1 3 1 4 | 1 1 1 1 x I 100 1 75 | 50 1 25 | 0 I 1 Vicat | 100 1 83 | 69 1 49 | 47 | 1 TSC 1 32 1 — | | 1 SD 1 -3 1 -3 1 -6 1 -15 | -20 | | RR 1 21 1 17 1 1 12 1 | I AR I 650 | 660 | 660 1 740 1 830 | 2 t 6100 6 - r>.

The composition of example 3 is converted to film of thickness 50 fjm by extrusion blowing. This film is used for heat sealing at 145*C by calendering po1yurethane-polyether foam and polypropylene fabric. The following 05 peeling forces, determined according to the ASTM 0 903-49 standard, are measured: between fabric and film: 13 N/5 cm: between film and foam: 8 N/5 cm.

When the film is additionally submitted to a Corona 10 treatment at 45 dynes/cm, the peeling force between film and foam reaches 13 N/5 cm.

A film (of the same thickness) of the polymer ''a, leads to a peeling force between film and foam ^ .. N/5 cm, Examples 6 and 7 Compositions are prepared by hot mixing of: x parts by weight of (A^) an ethylene/l-butene copolymer obtained by Ziegler type catalysis, having a density of 0.945 and a standard fluidity index of 0.18 dg/min; (100-x) parts by weight of the terpolymer (B) described in 20 ex amp 1es 1 to 5 .

The Vicat temperature as well as the melting temperature F (expressed in degrees Celsius) of the composition are reported in table II hereunder. Example 6 is * comparative ex ample.

TABLE II O I Example 6 7 | 1 8 1 1 x 100 50 | 0 1 I F 130 128 | 78 | 1 Vicat 122 75 | 47 | 216100 The composition of example 7 is converted into a film of [thickness] 50 jjm by extrusion blowing. This film is used for heat sealing at 145"C by calendering of the poly-urethane-polyether foam and the polypropylene fabric. The following peeling forces, determined according to the ASTM 0 903-49 standard are measured: between fabric and film: 10 N/5 cm; between film and foam: 5.5 N/5 cm, A film (of the same thickness) of the polymer (A^) alone leads to a peeling force between film and foam of 1 N/5 cm.

Examples 8 to 12 Compositions are prepared by hot kneading of: x parts by weight of (A^) a homopolymer of ethylene obtained by the free radical route and having a standard fluidity index of 3 dg/min; (100-x) parts by weight of (B) a terpolymer containing 97.9 mole percent of groups derived from ethylene, 1.2 mole percent of groups derived from butyl acrylate and 0.9 mole percent of groups derived from maleic anhydride and having a standard fluidity index of 4 dg/min.

The composition is extruded through a draw-plate to film of thickness 35 jjm which is coated at 297°C onto aluminium foil passing at a speed of 100 m/min. The adhesion of the composition to the substrate is measured by the peeling force in the longitudinal dimension FPL expressed in N/15 mm and determined according to the ASTM D 903-49 standard (width of the polymer web: 15 mm instead of 25 mm). The results are reproduced in table III, examples 8 and 12 being given for purposes of comparison. 216100 3 TABLE II! I E x amp 1e | 8 9 111 12 x I 100 JL 50 1 25 | 15 I 0| FPL J_ 0.4 | 6.4 | 6.1 1 5.7 | 5.3 | Example 13 (comparative) A composition is prepared consisting of: 50 parts by weight of a copolymer of ethylene and 1-butene of density equal to 0.940 and fluidity index equal to 4 dg/min marketed by the applicant under the designation LOTREX PG 0456. 50 parts by weight of alumina hydrate marketed by SAFIC-ALCAN under the designation HYORAL 710.

The preparation is carried out by mixing on a calender mixer at a temperature of 180 * C for 15 minutes. Using this mixture, plates of thickness 4 mm are compression-moulded at 180* C and subsequently cut into bars of dimensions 4 x 6 x 50 mm. The Charpy impact strength measured on these bars is equal to 7.8 kJ/m^ at -30°C.

Example 14 Using the operating conditions of example 13, a composition is prepared consisting of: 45 parts of the ethylene/1-butene copolymer used in ex amp 1e 13. 55 parts of the alumina hydrate used in example 13, previously coated in a terpolymer having a fluidity index equal to 7.8 dg/min. and consisting of 85.9 mole percent of ethylene, 13 mole percent of ethyl acrylate and 1.1 mole percent of maleic anhydride. The proportion by weight of the terpolymer to the alumina hydrate is 9/91.

Claims (14)

1. r
2. The Charpy impact strength of the composition, measured as
3. O in example 13. is equal to 55 kJ/m at -30*C.;216100;- 9 -;216100;- 10 -;WHAT WE CLAIM IS:;1. Thermoplastic composition comprising, per 100 parts by weight, from 1 to 93 parts by weight of at least one polymer or copolymer (A) based on ethylene, having a;05 density lying between 0.905 and 0.945, characterized in that it additionally comprises from 7 to 99 parts by weight of at least one copolymer (B) based on ethylene and maleic anhydr ide.;2. Thermoplastic composition according to claim 1.;10 characterized in that the polymer (A) is a copolymer of ethylene and at least one of-olefin having at least 3 carbon atoms.;3. Thermoplastic composition according to claim 1, characterized in that the polymer or copolymer (A) is 15 obtained by the free radical route and has a density lying between 0.910 and 0.935.;
4. 4. Thermoplastic composition according to one of claims 1 to 3, characterized in that the copolymer (B) also comprises groups derived from at least one ester of;—20 (meth)acry1ic acid.;
5. 5. Thermoplastic composition according to claim 4, characterized in that said copolymer (B) comprises:;from 83 to 98.7 mole percent of groups derived from ethylene,;\;-J 25 from 1 to 14 mole percent of groups derived from at least one ester of (meth)acry1ic acid, and from 0.3 to 3 mole percent of groups derived from maleic an hyd ride.;2 1 * » OCT -li-
6. 6. Thermoplastic composition according to one of claims 1 to 5. characterized in that the standard fluidity index of the copolymer (3) lies between 0.5 and 200 dg/min.
7. 7. Thermop1 astic composition according to one of claims 1 to 6, characterized in that it comprises, per 100 parts by weight, from 67 to 93 parts by weight of the polymer (A) and from 7 to 33 parts by weight of the copolymer (B).
8. 8. Thermop1 astic composition according to claim 7, characterized in that it also contains at least one mineral filling in a proportion of up to 100 parts by weight per 100 parts by weight of the mixture of the polymers (A) and (B).
9. 9. Thermoplastic composition according to one of claims 1 to 6, characterized in that it comprises, per 100 parts by weight, from 1 to 67 parts by weight of polymer (A) and from 33 to 99 parts by weight of copolymer (8).
10. 10. Thermoplastic composition according to one of claims 1 to 9. characterized in that the degree of crysta 11inity of the polymer (A) is not less than 30%.
11. 11. Thermoplastic composition according to claim 9, characterized in that the ratio of the standard fluidity index of the copolymer (B) to the standard fluidity index of the polymer (A) lies between 1 and 400.
12. 12. Industrial articles comprising at least one product obtained by conversion of a composition in accordance with one of claims 1 to 11.
13. 13. A thermoplastic composition as claimed in Claim 1 216100 and substantially as hereinbefore described with reference to any one of Examples 1 to
14. 14. SOCIETE CHIMIQUE DES CHARBONNAGES S.A. by their authorised agents - P.L. BERRY & ASSOCIATES per: ^ ^ /iu l- N.