ETHYLENE COPOLYMERS AND PROCESS FOR THE PRODUCTION THEREOF

Abstract

The present invention relates to an ethylene copolymer obtained by radical polymerisation through a high-pressure process comprising (i) 78.0 and 99.99 mole % of recurring units derived from ethylene; (it) 0.01 and 22.0 mole % of recurring units derived from comonomer A according to Formula (I), wherein R1 is composed of a saturated aliphatic moiety comprising 5-40 carbon atoms or R1 is composed of a saturated aliphatic moiety and consists of hydrogen atoms and 5-40 carbon atoms; R2 is selected from H or CH.sub.3; R3 is selected from O, (CO)(NH) or (CO)O; n=0 or 1 The ethylene copolymers have a reduced peak melting temperature and reduced enthalpy of fusion, indicating that these ethylene copolymers have a reduced degree of crystallinity and improved clarity, combined with a desired melt mass-flow rate.

##STR00001##

Claims

1. Ethylene copolymer obtained by radical polymerisation through a high-pressure process comprising: (i) 78.0 and 99.99 mole % of recurring units derived from ethylene; (ii) 0.01 and 22.0 mole % of recurring units derived from comonomer A according to Formula (I): ##STR00012## wherein R1 is composed of a saturated aliphatic moiety comprising 5-40 carbon atoms or R1 is composed of a saturated aliphatic moiety and consists of hydrogen atoms and 5-40 carbon atoms; R2 is selected from H or CH3; R3 is selected from O, (CO)(NH) or (CO)O; n=0 or 1

2. Ethylene copolymer according to claim 1 wherein the ethylene copolymer comprises (iii) 0 and 2.00 mole % of recurring units derived from comonomer B according to Formula (II): ##STR00013## wherein R4 is a moiety comprising 1-30 carbon atoms; each of R2 is individually selected from H or CH3; each of R3 is individually selected from O, (CO)(NH) or (CO)O; n=0 or 1; p=0 or 1; and m1 and 10;

3. Ethylene copolymer according to claim 1 wherein the ethylene copolymer comprises (iii) >0 and 2.00 mole % of recurring units derived from comonomer B according to Formula (II): ##STR00014## wherein R4 is a moiety comprising 1-30 carbon atoms; each of R2 is individually selected from H or CH3; each of R3 is individually selected from O, (CO)(NH) or (CO)O; n=0 or 1; p=0 or 1; and m1 and 10;

4. Ethylene copolymer according to claim 1 wherein comonomer A is a compound according to Formula (III): ##STR00015## wherein R1 is composed of a saturated aliphatic moiety comprising 5-40 carbon atoms or R1 is composed of a saturated aliphatic moiety consisting of hydrogen atoms and 5-40 carbon atoms, R2 is selected from H or CH3.

5. Ethylene copolymer according to claim 1 wherein R1 is composed of a saturated aliphatic moiety comprising 5-12 carbon atoms or wherein R1 is composed of a saturated aliphatic moiety and consists of hydrogen atoms and 5-12 carbon atoms.

6. Ethylene copolymer according to claim 1 wherein the comonomer B is a compound according to Formula (IV): ##STR00016## wherein R4 is a moiety selected from the group consisting of: CH2-; [CH2].sub.xCH(CH3)-, wherein x1 and 10; CH2-CH(OH)CH2-; CH2-CHR5-[OCH2-CHR5]q-, wherein q1 and 10, and each R5 individually is selected from CH3 and H; and m1 and 10 and each R2 is individually selected from H or CH3.

7. Ethylene copolymer according to claim wherein comonomer A is a compound selected from the list consisting of lauryl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, 10-udecenyl acrylate, behenyl acrylate, stearyl methacrylate, lauryl acrylate, isodecyl acrylate, isooctyl acrylate, octyl acrylate, tridecyl acrylate, 3,5,5-trimethylhexyl acrylate and isobornyl methacrylate and/or comonomer B is a compound selected from the list consisting of 1,4-butanediol dimethacrylate, hexanediol dimethacrylate, ethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, dodecanediol dimethacrylate, glycerol dimethacrylate, 1,4-butanediol diacrylate, hexanediol diacrylate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, dodecanediol diacrylate, glycerol diacrylate, glycerol 1,3-diglycerolate diacrylate, glycerol 1,3-diglycerolate dimethacrylate, poly(ethylene glycol) dimethacrylate, poly(propylene glycol) dimethacrylate, poly(ethylenepropyleneglycol) dimethacrylate, trimethylol propane trimethacrylate, trimethylol propane triacrylate, 1,4-butanediol divinyl ether, poly(ethylene glycol) divinyl ether, di(ethyleneglycol) divinyl ether, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene and 1,13-tetradecadiene.

8. Ethylene copolymer according to claim 1 wherein the copolymer comprises 78.0 and 99.99 mole % or 78.0 and 99.98 mole % of recurring units derived from ethylene; 0.01 and 22.0 mole % of recurring units derived from comonomer A wherein comonomer A is selected from the list consisting of lauryl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, 10-udecenyl acrylate, behenyl acrylate, stearyl methacrylate, lauryl acrylate, isodecyl acrylate, isooctyl acrylate, octyl acrylate, tridecyl acrylate, 3,5,5-trimethylhexyl acrylate and isobornyl methacrylate and 0 and 2.00 mole % or >0 and 2.00 mole % of recurring units derived from comonomer B wherein comonomer B is selected from 1,4-butanediol dimethacrylate, hexanediol dimethacrylate, 1,3-butylene glycol dimethacrylate, dodecanediol dimethacrylate, glycerol dimethacrylate, 1,4-butanediol diacrylate, hexanediol diacrylate, 1,3-butylene glycol diacrylate, dodecanediol diacrylate, poly(ethylene glycol) dimethacrylate, poly(propylene glycol) dimethacrylate.

9. Ethylene copolymer according to claim 1 wherein the ethylene copolymer has a melt mass-flow rate as determined in accordance with ISO 1133-1 (2011), at a temperature of 190 C. and a load of 2.16 kg, of 0.1 and 150.0 g/10 min.

10. Ethylene copolymer according to claim 1 wherein the ethylene copolymer has a peak melting temperature as determined according to ISO 11357-3 (2011) of 110 C. and an enthalpy of fusion of the melting peak as determined according to ISO 11357-3 (2011) of 120 J/g.

11. Ethylene copolymer according to claim 1 wherein the ethylene copolymer is produced in a tubular reactor.

12. Process for production of ethylene copolymers in a tubular reactor wherein: the process is performed at a pressure of 200 and 350 MPa, and a temperature of 100 and 350 C.; the process is performed in the presence of one or more free-radical initiator selected from organic peroxides and/or azo compounds; a mixture of reactants is introduced into the reactor comprising: (a) 78.0 and 99.99 mole % or 78.0 and 99.98 mole % ethylene; (b) 0.01 and 22.0 mole % of a comonomer A according to Formula (III): ##STR00017## wherein R1 is composed of a saturated aliphatic moiety comprising 5-40 carbon atoms R2 is selected from H or CH3. (c) 0 and 2.0 mole % or >0 and 2.0 mole % of a comonomer B according to Formula (IV): ##STR00018## wherein R4 is a moiety selected from the group consisting of: CH2-; [CH2].sub.x-CH(CH3)-, wherein x1 and 10; CH2-CH(OH)CH2-; CH2-CHR5-[OCH2-CHR5]q-, wherein q1 and 10, and each R5 individually is selected from CH3 and H; and m1 and 10; and each R2 may individually be selected from H or CH3.

13. Process according to claim 12 wherein comonomer A is selected from lauryl methacrylate, lauryl acrylate, hexyl methacrylate, hexyl acrylate, octyl acrylate and decyl acrylate and comonomer B is selected from 1,4-butanediol dimethacrylate, poly(ethylene glycol) dimethacrylate and poly(propylene glycol dimethacrylate).

14. (canceled)

15. Article comprising an ethylene copolymer according to claim 1 wherein the article is an extrusion coated article, a film, a foam, an adhesive, a bitumen modifier, a moulded article, a 3D printed article or a polymer alloy.

16. Article produced according to the process of claim 12.

Description

EXAMPLES

[0208] The materials listed below were used as comonomers in the examples.

TABLE-US-00001 BDDMA 1,4-butanediol dimethacrylate, CAS registry nr. 2082-81-7 LaurylMA Lauryl methacrylate, CAS registry nr. 142-90-5 BenzylMA Benzyl methacrylate, CAS registry nr. 2495-37-6 IsobornylMA Isobornyl methacrylate, CAS registry nr. 7534-94-3 HEMA (Hydroxyethyl)methacrylate, CAS registry nr. 868-77-9

Examples 1-8 and Comparative Example A-C

[0209] Preparation of Ethylene Copolymers

[0210] In a high-pressure stirred autoclave polymerisation reactor, ethylene copolymers were prepared by reacting a feed mixture comprising ethylene and an amount of comonomer as presented in Table I. In addition, a quantity of 1.45 mole % of isopropanol with regard to the molar quantity of ethylene was fed. In examples 5-8, a further quantity of 0.058 mole % propionaldehyde with regard to the molar quantity of ethylene was fed.

[0211] The reaction was performed at a pressure of 200 MPa. The reaction was initiated by addition of 4.0 g/l solution of t-butyl peroxy pivalate (t-BPP) in heptane, in quantities as indicated in Table I. t-BPP was fed in such quantity as to reach the desired temperature. The reaction temperature was kept at the temperature in C. as indicated in Table I. The average residence time in all examples was 45 s. The obtained ethylene polymer was collected.

TABLE-US-00002 TABLE I Exam- Comonomer A Comonomer B t-BPP Temperature ple (mole %) (mole %) (mole %) ( C.) 1 0.20 LaurylMA 0.0007 220 2 0.40 LaurylMA 0.0006 200 3 0.40 LaurylMA 0.0006 220 4 0.10 BenzylMA 0.0002 220 5 0.20 BenzylMA 0.0004 220 6 0.20 IsobornylMA 0.0005 220 7 0.40 LaurylMA 0.02 BDDMA 0.0007 200 8 0.40 LaurylMA 0.02 BDDMA 0.0017 220 A No comonomer 0.0004 220 B 1.2 HEMA 0.0036 220 C 0.2 HEMA 0.00068 220

[0212] The mole % relate to the amount of ethylene, comonomer A, comonomer B, t-BPP, heptane and of isopropanol, wherein sum thereof yield in 100 mole %.

[0213] 1.45 mole % of isopropanol is used as a solvent for the comonomer and 0.32 mole % of heptane is used as solvent for the t-BPP.

[0214] Properties of the Ethylene Copolymers Examples 1-8 and Comparative Examples A-C.

[0215] For each of the ethylene copolymers that were prepared using the feed mixtures and polymerisation conditions as presented in Table I, the material properties were determined as presented in Table II.

TABLE-US-00003 TABLE II Exam- Comonomer A Comonomer B MFR Tm H.sub.F ple (mole %) (mole %) (g/10 min) ( C.) (J/g) 1 1.6 11.8 99 77 2 3.3 10.9 101 89 3 3.0 43.0 101 87 4 0.5 0.50 111 138 5 0.8 10.0 78 47 6 1.4 17.0 106 119 7 3.2 0.2 3.96 99 78 8 3.0 0.2 38.1 107 109 A No comonomer 14.5 114 150 B 7.9 321 108 116 C 1.3 6.7 112 139 [0216] wherein:

[0217] The content of recurring units derived from comonomer A and from comonomer B is determined via NMR, wherein the sample is dissolved in deuterated tetrachloroethane at 120 C. The NMR spectra are recorded with a Bruker Avance 500 NMR spectrometer equipped with a 10 mm diameter cryo-cooled probe head, operating at 125 C., to obtain both .sup.1H-NMR and .sup.13C-NMR spectra, measuring time .sup.13C-NMR 3 hrs, .sup.1H-NMR 30 min.

[0218] Com. A: The quantity of recurring units derived from comonomer A in mole %, as determined via NMR according to the method presented above;

[0219] Com. B: The quantity of recurring units derived from comonomer B in mole %, as determined via NMR according to the method presented above;

[0220] The quantity of recurring units derived from ethylene in mole %, as determined via NMR according to the method presented above;

[0221] The quantities of recurring units derived from comonomer A, comonomer B and ethylene are expressed as molar fraction of the sum of units derived from comonomer A, comonomer B and ethylene, the total adding up to 100 mole %.

[0222] MFR: Melt mass-flow rate in g/10 min as determined in accordance with ISO 1133-1 (2011), at 190 C. under a load of 2.16 kg.

[0223] T.sub.m is the peak melting temperature in C. as determined via differential scanning calorimetry (DSC) according to ISO 11357-3 (2011) using a NETZSCH DSC 200PC differential scanning calorimeter.

[0224] H.sub.F is the enthalpy of fusion of the melting peak in Jig as determined according to ISO 11357-3 (2011) using a NETZSCH DSC 200PC differential scanning calorimeter.

[0225] The examples show that ethylene copolymers according to the present invention have a reduced peak melting temperature and reduced enthalpy of fusion, indicating that these ethylene copolymers have a reduced degree of crystallinity combined with a desired melt mass-flow rate.

[0226] Comparative sample B shows that a similar peak melting temperature and a similar enthalpy of fusion as compared to the inventive samples 1-8 is only obtained at a higher comonomer dosage and a higher mol % of incorporation.

[0227] Comparative sample C shows that at a similar comonomer dosage and a similar mol % of incorporation as compared to the inventive samples 1-8 a higher peak melting temperature and a higher enthalpy of fusion is obtained.

[0228] Especially comonomer B allows to reduce the MFI. Thereby the MFI can be controlled and the desired MFI is obtained. This is demonstrated by sample 7 in comparison to sample 2 and sample 8 in comparison to sample 3.