Laminated film comprising ethylene copolymer

Abstract

The invention is a polymer composition for film layer comprising less than 50 wt % of a copolymer of ethylene with silane group(s) containing units and at least 50 wt % of a thermoplastic polyolefine free from silane group(s) wherein the polymer composition has creep of less than 1 mm at 90° C., and an adhesion above 20 N/cm. The invention relates to a laminated article with at least one film layer of the polymer composition and a substrate.

Claims

1. A film layer made of a polymer composition comprising: (A) 10 to 50 wt % of a copolymer of ethylene with silane group(s) containing units having a density of from 910 kg/m.sup.3 to 960 kg/m.sup.3, and (B) at least 50 wt % of a thermoplastic polyolefin free from silane group(s) being a plastomer (E) having a density of from 860 kg/m.sup.3 to 915 kg/m.sup.3, wherein the densities are determined according to ISO1183D using test specimens according to ISO1872-2, wherein the polymer composition has creep of less than 1 mm at 90° C. during 48 hours, and an adhesion of above 20 N/cm.

2. The film layer according to claim 1, wherein the copolymer of ethylene (A) with a with silane group(s) containing units is in an amount from 10 to 45 wt %, based on the total weight of the polymer composition.

3. The film layer according to claim 1, wherein the thermoplastic polyolefin free from silane group(s) (B) is present in an amount from 60 to 90 wt %, based on the total weight of the polymer composition.

4. The film layer according to claim 1, wherein the total amount of silane group(s) in the polymer composition is less than 1 wt %.

5. The film layer according to claim 1, wherein the polymer composition has density of from 860 to 910 kg/m.sup.3 and a MFR.sub.2 of 1-10 g/10 min.

6. The film layer according to claim 1, wherein the polymer composition is free from peroxides.

7. The film layer according to claim 1, wherein the polymer composition has an UV stabilizer and an antioxidant present in an amount of 0.1 to 5 wt %, based on the total weight of the polymer composition.

8. The film layer according to claim 1, wherein the polymer composition comprises a condensation catalyst (F).

9. A laminated article comprising a substrate layer and at least one layer wherein the at least one layer comprises a polymer composition comprising: (A) 10 to 50 wt % of a copolymer of ethylene with silane group(s) containing units having a density of from 910 kg/m.sup.3 to 960 kg/m.sup.3, and (B) at least 50 wt % of a thermoplastic polyolefin free from silane group(s) being a plastomer (E) having a density of from 860 kg/m.sup.3 to 915 kg/m.sup.3, wherein the densities are determined according to ISO1183D using test specimens according to ISO1872-2, wherein the polymer composition has creep of less than 1 mm at 90° C. during 48 hours, and an adhesion of above 20 N/cm.

10. The laminated article according to claim 9, wherein the substrate layer is a glass layer.

11. The laminated article according to claim 9, wherein the polymer composition is laminated at 130° C. to 170° C.

12. The laminated article according to claim 9, wherein the copolymer of ethylene (A) with a with silane group(s) containing units is in an amount from 10 to 45 wt %, based on the total weight of the polymer composition.

13. The laminated article according to claim 9, wherein the thermoplastic polyolefin free from silane group(s) (B) is present in an amount from 60 to 90 wt %, based on the total weight of the polymer composition.

14. The laminated article according to claim 9, wherein the total amount of silane group(s) in the polymer composition is less than 1 wt %.

15. The laminated article according to claim 9, wherein the polymer composition has density of from 860 to 910 kg/m.sup.3 and a MFR2 of 1-10 g/10 min.

16. The laminated article according to claim 9, wherein the polymer composition is free from peroxides.

17. The laminated article according to claim 9, wherein the polymer composition has an UV stabilizer and an antioxidant present in an amount of 0.1 to 5 wt %, based on the total weight of the polymer composition.

18. The laminated article according to claim 9, wherein the polymer composition comprises a condensation catalyst (F).

Description

EXAMPLES

(1) Materials

(2) EVS (1.9 wt %): VTMS-ethylene copolymer produced by a high-pressure tubular reactor in a conventional manner using conventional peroxide initiator, with a max temperature of 285° C., where ethylene monomers were reacted with vinyl trimethoxysilane (VTMS) amounts so as to yield 1.9 wt % silane content in the copolymer. CTA was used to regulate MFR as well known for a skilled person. The melt flow rate (MFR2@190° C.) according to ISO 1133 (190° C., 2.16 kg) which is 1 g/10 min.

(3) UL04331, EVA (43 wt %): Ethylene vinyl acetate (EVA) copolymer, having a melt flow rate (MFR2@190° C.) according to ISO 1133 (190° C., 2.16 kg) which is 31 g/10 min and the content of vinyl acetate which is 43 wt % with regard to the total amount of monomers for the EVA. The saturated polyolefin were prepared by a high pressure polymerisation process. Produced and sold by Exxon Chemicals.

(4) Queo 8201: Copolymer of ethylene and 1-octene having a density of 882 kg/m3 and a melt flow rate according to ISO 1133 (190° C., 2.16 kg) which is 1 g/10 min. The polymer is produced with a metallocene catalyst in a solution polymerisation process. It is commercially available from Borealis.

(5) Queo 2M135: Copolymer of ethylene and 1-octene having a density of 882 kg/m3 and a melt flow rate according to ISO 1133 (190° C., 2.16 kg) which is 7 g/10 min. The polymer is produced with a metallocene catalyst in a solution polymerisation process. It is commercially available from Borealis.

(6) EVS (1.3 wt %) MA (24 wt %) Terpolymer produced by a high-pressure (250MPa) tubular reactor in a conventional manner using conventional peroxide initiator, with a max temperature of 285° C., where ethylene monomers were reacted with vinyl trimethoxysilane (VTMS) and methylacrylate (MA) co-monomers amounts so as to yield 1.3 wt % silane content and 24 wt % MA content in the terpolymer. CTA was used to regulate MFR as well known for a skilled person. The melt flow rate (MFR2@190° C.) according to ISO 1133 (190° C., 2.16 kg) which is 25 g/10 min.

(7) PVB from Solutia, Saflex PVB PA61

(8) Results

(9) Table 1 shows the impact on creep performance when adding EVS (1.9 wt %) with a higher melting temperature. Adding 20% of EVS (1.9 wt %) to Queo 8201 will make the sample pass the creep test at 110° C. In this test is the preferred composition 20% EVS (1.9 wt %), 80% Queo 8201, solving the creep issue while having a limited influence on optical performance.

(10) TABLE-US-00002 TABLE 1 Results on creep test. Tests were sequentially performed starting at 90° C.. Creep Creep Creep EVS 90° C. 110° C. 115° C. (1.9 Queo Movement Movement Movement wt %) 8201 after 48 h after 72 h after 18 h 100 0  0 mm 0 mm  0 mm 80 20  0 mm 0 mm  1 mm 60 40  0 mm 0 mm  5 mm 40 60  0 mm 0 mm 10 mm 20 80  0 mm 0 mm  7 mm 0 100 >20 mm Failure Failure

(11) The results at 115° C. indicates that the absence of creep at 110° C. is a result of the high melting temperature of EVS (1.9 wt %). When passing the melting point of EVS (1.9 wt %) (Tm is 108° C.) the samples start to creep. However, after 48 h at 115° C. the samples had not moved relative to the results after 18 h. Results in Table 2 concludes that a blend of EVS (1.9 wt %): Queo 8201 (20:80) does not need to be crosslinked to pass the creep test at 110° C.

(12) Transmittance of pure plastomer and plastomer/EVS blends using an integrating sphere.

(13) TABLE-US-00003 TABLE 2 Transmittance of blends EVS Total transmittance 400-1150 nm. (1.9 wt %) Queo 8201 Queo 2M135  0% 89.7% 90.4% 10% 88.1% 20% 87.5% 86.6% 30% 85.4% 40% 86.2% 84.3%

(14) By adding up till 40 wt % of an EVS (1.9 wt %) copolymer into the Queo Plastomer material the total transmittance is still on such a high level to make these Queo Plastomer compounds with EVS is an excellent material to be used as film material in a laminated article.

(15) TABLE-US-00004 TABLE 3 Adhesion of the blends of Queo2M135 and EVS (1.9 wt %) Max. Min. Mean Force Force Force Adhesion Sample (N) (N) (N) (N/cm) 100% QUEO 2M135 no adhesion 10% EVS (1.9 wt %) 101 43 55 37 90% Queo 2M135 20% EVS (1.9 wt %) 128 37 99 67 80% Queo 2M135 30% EVS (1.9 wt %) 179 67 118 78 70% Queo 2M135 40% EVS (1.9 wt %) 260 — 264 176 60% Queo 2M135 60% EVS (1.9 wt %) 47 60 40 40% Queo 2M135 70% EVS (1.9 wt %) 68 30 44 29 30% Queo 2M135 80% EVS (1.9 wt %) no adhesion 20% Queo 2M135 90% EVS (1.9 wt %) no adhesion 10% Queo 2M135 100% EVS (1.9 wt %) no adhesion

(16) Pure Queo 2M135 shows no adhesion to glass due to the lack of trimethoxysilane groups, see Table 3. By blending in an EVS copolymer into the plastomer the adhesion increases with the amount of EVS due to the higher amount of silane in the compound. By adding 60 wt % of and EVS copolymer or more the adhesion surprisingly decreases instead of a higher amount of silane groups in the compound.

(17) TABLE-US-00005 TABLE 4 Water uptake EVS 2M135/ 2M135/ 2M135/ EVA (1.3 wt %) EVS (1.9 EVS (1.9 EVS (1.9 UL043 PVB Queo Queo EVS MA wt %) wt %) wt %) 31 Solutia 2M135 8201 (1.9 wt %) (24 wt %) 90/10 wt % 80/20 wt % 70/30 w t% 764 925 13 32 32 185 45 34 32 ppm ppm ppm ppm ppm ppm ppm ppm ppm

(18) The water uptake measurements were done on the extruded films with a thickness of 0.45 mm and a length of 200 mm. The examined films were conditioned for 3 weeks in a constant room at 23° C. and a RH of 50%. The plastomer and EVS copolymer blends have a very low water uptake, see Table 4. Film materials should have very low or near zero water uptake and low water vapour transmission rate.

(19) TABLE-US-00006 TABLE 5 Adding EVS (1.9 wt %) works as process aid for Queo8201 η* 0.05 rad/s η* 300 rad/s SHI MFR [Pa .Math. s] [Pa .Math. s] (0.05/300) (190, 2.16) EVS (1.9 wt %)/ 799 186 4.29 14.68 Queo8230 (20/80) EVS (1.9 wt %)/ 2063 218 9.46 7.87 Queo8230 (40/60) EVS (1.9 wt %)/ 5010 251 19.96 3.81 Queo8230 (60/40) EVS (1.9 wt %)/ 10800 288 37.5 1.68 Queo8230 (80/20) EVS (1.9 wt %)/ 14020 708 19.80 0.96 Queo8201 (20/80) EVS (1.9 wt %)/ 19960 413 48.32 0.72 Queo8201 (80/20)

(20) The samples were compounded as above. The rheological parameters of the blends are given in the table 5. The SHI as calculated by ratio of viscosity at 0.05/300 rad.Math.s−1, clearly shows that with increasing amount of the EVS (1.9 wt %) the shear thinning increases, meaning the processability at high shear stress is improved.

(21) TABLE-US-00007 TABLE 6 blends of Queo and EVS copolymer and EVS MA terpolymer Blend Composition Soft Phase (%) Queo 2M135/EVS (1.9 wt %) 60/40 <0.1 Queo 2M135/EVS (1.9 wt %) 80/20 <0.1 Queo 2M135/EVS (1.9 wt %) 20/80 <0.1 Queo 8201/EVS (1.9 wt %) 20/80 0.2 Queo 8201/EVS (1.9 wt %) 40/60 0.4 Queo 8201/EVS (1.9 wt %) 60/40 0.1 Exact 8230/EVS (1.3 wt %) MA 80/20 7.2 (24 wt %) Exact 8230/EVS (1.3 wt %) MA 60/40 10.0 (24 wt %) Exact 8230/EVS (1.3 wt %) MA 20/80 42.3 (24 wt %)

(22) 0.45 mm films were made as described above. The films were cry cut at −100° Celsius and analysed with an AFM in AC-mode using a cantilever AC 200TS. The results were analysed with Asylum Software Analyse program. The soft phase indicates that the samples have phase separation. The table 6 shows that a copolymer of ethylene and vinyl trimethoxy silane together with a plastomer gives a one phase system while a terpolymer of ethylene, vinyl trimethoxy silane and methylacrylate gives a two phase system, which is bad for optical properties.