PROCESS FOR PREPARING A BIAXIALLY ORIENTED MULTILAYERED FILM

• US 20200131321A1
• Filed: 04/19/2018
• Published: 04/30/2020
• Est. Priority Date: 04/21/2017
• Status: Abandoned Application

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Inventors: STROEKS, Alexander Antonius Marie, CHEN, Hao
• Application Number:
  US16/606,424
• Publication Number:
  US 20200131321A1
• Time in Patent Office: Days
• CPC Class Codes: B29C 48/0018 combined with shaping by orienting, stretching or shrinking, e.g. film blowing B29C48/0017 takes precedence
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 55/143 firstly parallel to the direction of feed and then transversely thereto
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/0039 Amorphous
• CPC Class Codes: B29K 2995/004 Semi-crystalline
• CPC Class Codes: B29K 2995/0053 bi-axially
• CPC Class Codes: B32B 2250/24 All layers being polymeric
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/544 Torsion strength; Torsion stiffness
• CPC Class Codes: B32B 2307/546 Flexural strength; Flexion stiffness
• CPC Class Codes: B32B 2307/581 Resistant to cut
• CPC Class Codes: B32B 2307/5825 Tear resistant
• CPC Class Codes: B32B 2307/702 Amorphous
• CPC Class Codes: B32B 2307/704 Crystalline
• CPC Class Codes: B32B 2307/7244 Oxygen barrier
• CPC Class Codes: B32B 2307/7246 Water vapor barrier
• CPC Class Codes: B32B 2307/734 : Dimensional stability
• CPC Class Codes: B32B 2307/75 : Printability
• CPC Class Codes: B32B 2410/00 : Agriculture-related articles
• CPC Class Codes: B32B 2439/70 : Food packaging
• CPC Class Codes: B32B 2439/80 : Medical packaging
• CPC Class Codes: B32B 27/08 : of synthetic resin
• CPC Class Codes: B32B 27/32 : comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/34 : comprising polyamides
• CPC Class Codes: B32B 7/12 : using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08J 2377/06 : Polyamides derived from polyamines and polycarboxylic acids C08J2377/10 takes precedence
• CPC Class Codes: C08J 2423/12 : Polypropene
• CPC Class Codes: C08J 2477/06 : Polyamides derived from polyamines and polycarboxylic acids C08J2477/10 takes precedence
• CPC Class Codes: C08J 5/128 : Adhesives without diluent
• CPC Class Codes: C08J 5/18 : Manufacture of films or sheets
• CPC Class Codes: C08L 2201/10 : Transparent films; Clear coatings; Transparent materials
• CPC Class Codes: C08L 2203/16 : used for films
• CPC Class Codes: C08L 2205/025 : containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 2205/03 : containing three or more polymers in a blend
• CPC Class Codes: C08L 2205/12 : containing additives being liquid crystalline or anisotropic in the melt
• CPC Class Codes: C08L 77/06 : Polyamides derived from polyamines and polycarboxylic acids C08L77/10 takes precedence
• CPC Class Codes: C09J 123/12 : Polypropene
• CPC Class Codes: C09J 2423/10 : Presence of homo or copolymers of propene
• CPC Class Codes: C09J 2423/108 : in the pretreated surface to be joined
• CPC Class Codes: C09J 2477/008 : in the pretreated surface to be joined
• CPC Class Codes: C09J 5/00 : Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers

Abstract

The invention relates to a process for preparing a biaxially oriented multilayered film, the film comprising at least one layer comprising a polyolefin composition and at least one layer comprising a polyamide composition, the process comprising the steps of: a) Melting a polyamide composition comprising: i. a semi-crystalline polyamide Y comprising: ⋅monomeric units derived from caprolactam in an amount of at least 75 wt %; ⋅monomeric units derived from an aliphatic diamine in an amount of between 2.5 and 12.5 wt %; ⋅monomeric units derived from an aromatic diacid in an amount of between 2.5 and 12.5 wt %; wherein the weight percentage is given with respect to the total weight of the polyamide Y; ii. an amorphous polyamide in an amount of between 2.5 and 50 wt % with respect to the total weight of the polyamide composition; wherein the amorphous polyamide comprises: ⋅monomeric units derived from an aliphatic diamine X in an amount of between 30 and 70 wt %; ⋅monomeric units derived from an aromatic diacid in an amount of between 30 and 70 wt %; wherein the weight percentage is given with respect to the total weight of the amorphous polyamide; b) Melting a composition comprising a polyolefin; c) Co-extruding at least the melts obtained from a) and b) to form a film of at least two layers; d) Cooling the film to a temperature of at most 50° C., while the film is transported in a direction, referred to as machine direction; e) Stretching the film obtained in step d) with a stretch ratio of at least 13, at a temperature between the Tg of polyamide Y and Tm of the polyolefin, wherein the stretch ratio is defined as being the product of the stretch ratio parallel to the machine direction and the stretch ratio perpendicular to the machine direction. The invention also relates to a biaxially oriented multilayered film obtainable by the process.

Claims

1. Process for preparing a biaxially oriented multilayered film, the film comprising at least one layer comprising a polyolefin composition and at least one layer comprising a polyamide composition, the process comprising the steps of:

a) Melting a polyamide composition comprising;

b) Melting a composition comprising a polyolefin;

c) Co-extruding at least the melts obtained from a) and b) to form a film of at least two layers;

d) Cooling the film to a temperature of at most 50°

C., while the film is transported in a direction, referred to as machine direction;

e) Stretching the film obtained in step d) at a temperature between the Tg of polyamide Y and Tm of the polyolefin;

wherein the polyamide composition comprises;

i. a semi-crystalline polyamide Y comprising;

monomeric units derived from caprolactam in an amount of at least 75 wt %;

monomeric units derived from an aliphatic diamine in an amount of between 2.5 and 12.5 wt %;

monomeric units derived from an aromatic diacid in an amount of between 2.5 and 12.5 wt %;

 

wherein the weight percentage is given with respect to the total weight of the polyamide Y;

ii. an amorphous polyamide in an amount of between 2.5 and 50 wt % with respect to the total weight of the polyamide composition;

wherein the amorphous polyamide comprises;

monomeric units derived from an aliphatic diamine X in an amount of between 30 and 70 wt %;

monomeric units derived from an aromatic diacid in an amount of between 30 and 70 wt %;

 

wherein the weight percentage is given with respect to the total weight of the amorphous polyamide;

and wherein in step e) the film is stretched with a stretch ratio of at least 13, the stretch ratio being defined as the product of the stretch ratio parallel to the machine direction and the stretch ratio perpendicular to the machine direction.

2. Process according to claim 1, wherein the amorphous polyamide comprises monomeric units derived from an aromatic diacid selected from terephthalic acid (T), isophthalic acid (I), and naphthalic acid.

3. Process according to claim 1, wherein the amorphous polyamide is PA-XI/XT, wherein X denotes the monomeric units derived from an aliphatic diamine X and I and T denote monomeric units derived from an aromatic diacid isophthalic acid (I) and terephthalic acid (T) respectively.

4. Process according to claim 3, wherein the molar ratio isophthalic acid over terephthalic acid is at least 1.5.

5. Process according to claim 1, wherein the amorphous polyamide comprises monomeric units derived from an aliphatic diamine X selected from 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane and 1,7-diaminoheptane.

6. Process according to claim 1, wherein the amorphous polyamide is PA-6I/6T.

7. Process according to claim 1, wherein the polyamide Y is PA-6/6T, wherein the amount of 6T is between 5 and 25 wt % with respect to the total weight of polyamide Y.

8. Process according to claim 1, wherein the polyamide composition employed at step a) substantially consists of PA-6/6T and PA-6I/6T.

9. Process according to claim 1, wherein the composition of step b) comprises a polyolefin selected from polyethylene, polypropylene, polybutylene, polyoctene, polymethylpentene and copolymers thereof.

10. Process according to claim 1, wherein the process further comprises a step of providing an adhesive layer between the layers originating from a) and b), by co-extruding in step c) a functionalized polyolefin.

11. Process according to claim 10, wherein the functionalized polyolefin is selected from maleic-anhydride functionalized polyethylene, epoxy functionalized polyethylene, maleic-anhydride functionalized polypropylene and epoxy functionalized polypropylene.

12. Process according to claim 1, wherein the stretching ratio is at least 15.

13. Process according to claim 1, wherein stretching in step e) is first performed in a direction parallel to the machine direction and subsequently in a direction perpendicular to the machine direction.

14. Process according to claim 1, wherein stretching in step e) is performed simultaneously in a direction parallel to the machine direction and in a direction perpendicular to the machine direction.

15. Biaxially oriented multilayered film obtainable by the process according to claim 1, comprising at least one layer comprising a polyolefin composition and at least one layer comprising a polyamide composition, and having a stretch ratio of at least 13, wherein the stretch ratio is defined as being the product of the stretch ratio parallel to the machine direction and the stretch ratio perpendicular to the machine direction,

wherein the polyamide composition comprises:

i. a semi-crystalline polyamide Y comprising;

monomeric units derived from caprolactam in an amount of at least 75 wt %;

monomeric units derived from an aliphatic diamine in an amount of between 2.5 and 12.5 wt %;

monomeric units derived from an aromatic diacid in an amount of between 2.5 and 12.5 wt %;

 

wherein the weight percentage is given with respect to the total weight of the polyamide Y;

ii. an amorphous polyamide in an amount of between 2.5 and 50 wt % with respect to the total weight of the polyamide composition;

wherein the amorphous polyamide comprises;

monomeric units derived from an aliphatic diamine X in an amount of between 30 and 70 wt %;

monomeric units derived from an aromatic diacid in an amount of between 30 and 70 wt %;

 

wherein the weight percentage is given with respect to the total weight of the amorphous polyamide.