Stock material or miscellaneous articles – Structurally defined web or sheet – Physical dimension specified
Patent
1990-09-10
1992-11-17
Thibodeau, Paul J.
Stock material or miscellaneous articles
Structurally defined web or sheet
Physical dimension specified
428336, 428458, 428480, 428481, 428483, 15624411, 2642095, B32B 2710, B32B 2732, B32B 2736
Patent
active
051642484
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to oriented composite polyester films exhibiting, in particular, an improved adhesion to various final application coatings and to a process for obtaining them.
The expression "final application coatings", as used in the present invention, indicates coatings which impart to the oriented polyester films properties which make possible extremely diverse industrial applications, well known to the expert. It is known that in the case of a number of industrial applications, the polyester films cannot be employed directly but only after deposition of a coating adapted to each type of application; examples which may be mentioned are matting coatings intended for manual drawing or for tracing tables, photosensitive coatings for photographic applications, diazo coatings for microfilms applications, printing plans or reprography, printing coatings, magnetic coatings for the acquisition of various data (sound, images, data processing), metal coatings, and coatings which modify the gas-permeability properties of polyester films employed as packaging (polyethylene, polyvinyl alcohol or polyvinylidene chloride coatings, for example).
It is also known that, owing to their nature, the bonding of final application coatings to the surface of polyester films is not easy. In fact, biaxially drawn polyester films have a relatively smooth surface and exhibit a limited chemical reactivity and a very low sensitivity to solvents. In most cases it is therefore necessary to use an "adhesion primer" coating, permitting the anchoring of the use layers, according to more or less complex chemical formulae. As a general rule, this adhesion primer (or anchor layer) is applied by the converter. It is therefore easy for the latter to adapt the nature of the primer to the ultimate application.
Film manufacturers themselves have attempted to modify the surface of the films by various means. The use of polymers of various kind as an adhesion primer has been proposed for this purpose. A particularly advantageous class of polymers employed for this purpose consists of copolyesters containing a plurality of hydrophilic groups and especially of hydroxysulphonyl groups or their metal salts (for convenience, free sulphonic acid groups or sulphonic acid salts will be denoted by the expression "oxysulphonyl group " in what follows). The deposition of adhesion primers of this type can be carried out either by coating the base film with an aqueous dispersion or solution (cf. French Patents No. 1,401,581 and 1,602,002), or by coextrusion or lamination (cf. Japanese Patent Application published under No. 79/153,883). In European Patent No. 0,129,674 it has been proposed to use copolyesters containing particular oxysulphonyl groups to obtain composite polyester films with improved adhesion having an adhesion primer deposited by coating. These copolyesters are characterized by a specific composition and in particular by the presence of 15 to 25 mol %, based on the total of the diacid repeat units, of repeat units derived from aliphatic diacids containing from 3 to 13 carbon atoms and from 6 to 15 mol % of units derived from an aromatic dicarboxylic acid containing oxysulphonyl group(s); this particular composition of the sulphonated copolyesters makes them water-dispersible and endows the anchor layers obtained with a wider range of potential applications, since they improve the adhesion of the polyester film both in the case of aqueous final application coatings and in the case of those containing organic solvents. Despite their advantage, the composite films described in European Patent No. 0,129,674 suffer from the disadvantage of having to be manufactured by coating.
The deposition of an adhesion primer of the copolyester type containing oxysulphonyl groups by coating involves resorting to copolyesters with high contents of repeat units containing oxysulphonyl groups in order to enable them to be dispersed or dissolved in water; these contents must be higher than 6 mol %. Resorting to coating, therefore, does not make it pos
REFERENCES:
patent: 4476189 (1984-10-01), Posey et al.
patent: 4525419 (1985-06-01), Posey et al.
patent: 4585687 (1986-04-01), Posey et al.
patent: 4605591 (1986-08-01), Nose et al.
Assante Jean-Pierre
Corsi Philippe
Fleury Etienne
Vovelle Louis
Nakarani D. S.
Rhone-Poulenc Chimie
Thibodeau Paul J.
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