Meta-xylylene diamine/aliphatic dicarboxylic acid polyamide film

Claim 2

A biaxially drawn film of a polyamide which is produced by subjecting an undrawn film of polyamide to simultaneous or stepwise biaxial drawing at a temperature within a range as calculated according to the following inequality in the case of simultaneous drawing: -10W + 120 + 12 log (δ/1000) > T ≧ -6W + 80 or according to the following inequality in the case of stepwise drawing: -10W + 130 + 7 log (δ/1000) > T ≧ -6W + 80 wherein W is the moisture content in % by weight of the undrawn film, δ is the speed in % per minute and T is the drawing temperature in ° C., said polyamide containing not less than 70 mole % of repeating units of an α,δ-aliphatic dicarboxylic acid having 6 to 10 carbon atoms and metaxylylendiamine or a mixture of metaxylylenediamine and paraxylylenediamine, the amount of paraxylylenediamine present in the polyamide being not more than 30 mole % of the total amount of metaxylylenediamine and paraxylylenediamine, the balance of said polyamide being units of a polyamide-forming monomer copolymerizable with said repeating units.

Claim 3

A biaxially drawn film of a polyamide which is produced by subjecting an undrawn film of polyamide to simultaneous or stepwise biaxial drawing at a temperature within a range as calculated according to the following inequality in the case of simultaneous drawing: -10W + 120 + 12 log (δ/1000) > T ≧ -6W + 80 or according to the following inequality in the case of stepwise drawing: -10W + 130 + 7 + log (δ/1000) > T ≧ -6W + 80 wherein the moisture content W is from 0.1 to 5% by weight, the drawing speed δ is from 500 to 50,000 %/min in the case of simultaneous drawing and from 500 to 500,000 %/min in the case of stepwise drawing and T is the drawing temperature in ° C., said polyamide containing not less than 70 mole % of repeating units of an α,ω-aliphatic dicarboxylic acid having 6 to 10 carbon atoms and metaxylylenediamine or a mixture of metaxylylenediamine and paraxylylenediamine, the amount of paraxylylenediamine present in the polyamide being not more than 30 mole % of the total amount of metaxylylenediamine and paraxylylenediamine, the balance of said polyamide being units of a polyamide-forming monomer copolymerizable with said repeating units and being selected from the group consisting of aliphatic amines, alicyclic diamines, aromatic diamines, aromatic dicarboxylic acids, lactams, ω-aminocarboxylic acids and aromatic aminocarboxylic acids, said drawn film having an oxygen permeability coefficient of from 2.6 × 10 -13 to 5 × 10 -13 ml. cm/cm..sup. 2 sec. cm Hg, a breaking strength of from 14 to 29.8 kg/mm 2 , a breaking elongation of from 30 to 150%, a yield strength of from 7 to 13.8 kg/mm 2 , a yield elongation of from 2 to 6%, a plane orientation index of from 0.025 to 0.040, and a degree of balance of from 0.003 to 0.045.

Claim 4

A biaxially drawn film of a polyamide which is produced by subjecting an undrawn film of polyamide to simultaneous or stepwise biaxial drawing at a temperature within a range as calculated according to the following inequality in the case of simultaneous drawing: -10W + 120 + 12 log (δ/1000) > T ≧ -6W + 80 or according to the following inequality in the case of stepwise drawing: -10W + 130 + 7 + log (δ/1000) > T ≧ -6W + 80 wherein the moisture content W is from 0.1 to 5% by weight, the drawing speed δ is from 500 to 50,000 %/min in the case of simultaneous drawing and from 500 to 500,000 %/min in the case of stepwise drawing and T is the drawing temperature in ° C., said polyamide containing not less than 70 mole % of repeating units of an α,ω-aliphatic dicarboxylic acid having 6 to 10 carbon atoms and metaxylylenediamine or a mixture of metaxylylenediamine and paraxylylenediamine, the amount of paraxylylenediamine present in the polyamide being not more than 30 mole % of the total amount of metaxylylenediamine and paraxylylenediamine, the balance of said polyamide being units of a polyamide-forming monomer copolymerizable with said repeating units and being selected from the group consisting of aliphatic amines, alicyclic diamines, aromatic diamines, aromatic dicarboxylic acids, lactams, ω-aminocarboxylic acids and aromatic aminocarboxylic acids, said drawn film having an oxygen permeability coefficient of from 2.6 × 10 -13 to 5 × 10 -13 ml. cm/cm..sup. 2 sec. cm Hg, a breaking strength of from 14 to 29.8 kg/mm 2 , a breaking elongation of from 30 to 150%, a yield strength of from 7 to 13.8 kg/mm 2 , a yield elongation of from 2 to 6%, a plane orientation index of from 0.025 to 0.040, and a degree of balance of from 0.003 to 0.045.

Claim 5

The drawn film according to claim 1, wherein the undrawn film is made of a polyamide having a relative viscosity of about 2.0 to 4.0 as measured with a solution thereof in 96% sulfuric acid at a concentration of 1 g/100 ml at 25° C.

Claim 6

The drawn film according to claim 1, wherein the drawing is effected simultaneously with a drawing speed of from about 500 to 50,000 %/min.

Claim 7

The drawn film according to claim 1, wherein the drawing is effected stepwise with a drawing speed of about 500 to 500,000 %/min. in the longitudinal direction and a drawing speed of about 500 to 50,000 %/min. in the latitudinal direction.

Claim 8

The drawn film according to claim 1, wherein the drawing is effected at a draw ratio of about 2 to 6 in each of the longitudinal and latitudinal directions.

Claim 9

The drawn film according to claim 1, wherein the undrawn film has a moisture content of 0.1 to 5% by weight.

Claim 10

The drawn film according to claim 1, wherein the drawn film is further subjected to heat treatment at a temperature between about 5° C., above the drawing temperature during the production of the drawn film and the melting temperature of the drawn film.

Claim 11

The drawn film according to claim 8, wherein the heat treatment is effected for a period of not more than about 5 minutes.

Claim 12

The drawn film according to claim 1, wherein the drawn film is further subjected to heat treatment at a temperature between about 5° C. above the drawing temperature during the production of the drawn film and the melting temperature of the drawn film, whereby the degree of crystallinity of the film is increased and the strain produced on the film in the drawing process is eliminated, thereby substantially improving the mechanical properties and the size stability thereof.

Claim 13

The drawn film according to claim 2, wherein said oxygen permeability coefficient is 2.6 × 10 -13 to 4.6 × 10 -13 ml. cm/cm. 2 sec. cm Hg, said breaking strength is 14.1 to 29.8 kg/mm 2 , said breaking elongation is 38 to 117%, said yield strength is 11.1 to 13.8 kg/mm 2 , said yield elongation is 3.1 to 4.2%, said plane orientation index is 0.026 to 0.040, and said degree of balance is 0.003 to 0.014.

Claim 14

The drawn film according to claim 1, wherein said copolymerizable polyamide-forming monomer is selected from the group consisting of aliphatic amines, alicyclic diamins, aromatic diamines, aromatic dicarboxylic acids, lactams, ω-aminocarboxylic acids and aromatic aminocarboxylic acids.