Biaxially oriented copolyester film and laminates thereof with copper

A biaxially-oriented polyester film produced from a polyester comprising:

• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues,
• wherein the polyester film has a thickness of 70 to 150 microns,
• wherein the polyester film is produced by stretching an essentially amorphous cast film of thickness between about 450 and 1800 microns at a ratio from about 2.5×2.5 to 3.5×3.5 while being held at a temperature between 90° C. and 130° C., and heat-setting the stretched film at an actual film temperature of from 260° C. to Tm, where Tm is the melting point of the polyester as measured by differential scanning calorimetry (DSC), while maintaining the dimensions of the stretched film, and
• wherein the polyester film undergoes not more than 3% shrinkage when immersed for 10 seconds in a solder bath preheated to 260° C.

A thermoplastic article comprising one or more laminates, wherein at least one of said laminates comprises in order:

• I. a thermally curable adhesive;
• and
• II. a biaxially-oriented polyester film produced from a polyester comprising:
• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues, and
• wherein the polyester film has a thickness of 70 to 150 microns.

A process for the preparation of a thermoplastic article comprising one or more laminates, wherein at least one of said laminates comprises in order:

• I. a copper layer;
• II. a thermally curable adhesive;
• and
• III. a biaxially-oriented polyester film produced from a polyester comprising:
• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues, and
• wherein the polyester film has a thickness of 70 to 150 microns,
• said process comprising heating said laminate at a temperature of about 120 to 180° C. under pressure for a period of time sufficient to cure the thermally curable adhesive.

A flexible electronic circuit board comprising at least one biaxially-oriented polyester film produced from a polyester comprising:

• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues, and
• wherein the polyester film has a thickness of 70 to 150 microns.

A biaxially-oriented polyester film produced from a polyester comprising:

• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues, and
• wherein said polyester film undergoes not more than 3% shrinkage when immersed for 10 seconds in a solder bath preheated to 260° C.

A biaxially-oriented polyester film produced from a polyester comprising:

• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues,
• wherein the polyester film is produced by stretching an essentially amorphous cast film of thickness between about 450 and 1800 microns at a ratio from about 2.5×2.5 to 3.5×3.5 while being held at a temperature between 90° C. and 130° C., and heat-setting the stretched film at an actual film temperature of from 260° C. to Tm, where Tm is the melting point of the polyester as measured by differential scanning calorimetry (DSC), while maintaining the dimensions of the stretched film, and
• wherein the polyester film undergoes not more than 3% shrinkage when immersed for 10 seconds in a solder bath preheated to 260° C.

A thermoplastic article comprising one or more laminates, wherein at least one of said laminates comprises in order:

• I. a thermally curable adhesive;
• and
• II. a biaxially-oriented polyester film produced from a polyester comprising:
• (a) diacid residues comprising between about 95 and about 100 mole percent of terephthalic acid residues;
• (b) diol residues comprising between about 95 and about 100 mole percent of 1,4-cyclohexanedimethanol residues;
• and
• (c) about 0.5 to about 5 mole percent of another dicarboxylic acid or diol residue,
• wherein the polyester comprises a total of 100 mole percent diacid residues and a total of 100 mole percent diol residues, and
• wherein said polyester film undergoes not more than 3% shrinkage when immersed for 10 seconds in a solder bath preheated to 260° C.