Woven/knit fabric with reversible air premeability and production process thereof

1. At least one of a woven fabric and a knit fabric containing composite yarn comprising a multifilament yarn A2 and a multifilament yarn B2, wherein:

the ratio (WA2/DA2) of the yarn length of the multifilament fiber A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn A2 under conditions of 20° C. and 65% humidity (DA2) is 1.02 to 1.30;

the ratio (WA2/DB2) of the yarn length of the multifilament yarn A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn B2 under conditions of 20° C. and 65% humidity (DB2) is 0.9 to 1.1;

the drying shrinkage stress (DS value) of the multifilament yarn A2 is 0.08 cN/dtex or more;

the multifilament yarn A2 is regenerated fibers;

the multifilament yarn B2 is a polyester multifilament yarn having terephthalic acid as a main component thereof and having at least one alkylene glycol as a main glycol component thereof;

a change in yarn length of the multifilament yarn B2 is 0% when comparing the length under conditions of 20° C. and 65% humidity and the length during absorption of moisture and/or water; and

a maximum weight per square meter of the woven fabric or the knit fabric under conditions of 20° C. and 65% humidity is 0.85 times that of the weight per square meter of the woven fabric or the knit fabric during absorption of moisture and/or water.

2. The fabric according to claim 1 , wherein said fabric contains 20% by weight or more of the composite yarn, and wherein the weight per square meter of the fabric when dry is 100 to 350 g/m 2 , wherein:

the amount of change in air permeability is 10% or more: amount of change in air permeability (%)={[(air permeability at water content of 50% by weight)−(initial air permeability when dry)]/(initial permeability when dry)}×100, and

the initial air permeability when dry is 350 cm 3 /cm 2 /sec or less.

3. The fabric according to claim 1 , wherein said regenerated fibers are rayon or cuprammonium rayon.

4. The fabric according to claim 1 , wherein said alkylene glycol is at least one selected from the group consisting of ethylene glycol, trimethylene glycol and tetramethylene glycol.

5. At least one of a woven fabric and a knit fabric containing composite yarn comprising a multifilament yarn A2 and a multifilament yarn B2, wherein:

the ratio (WA2/DA2) of the yarn length of the multifilament fiber A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn A2 under conditions of 20° C. and 65% humidity (DA2) is 1.02 to 1.30;

the ratio (WA2/DB2) of the yarn length of the multifilament yarn A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn B2 under conditions of 20° C. and 65% humidity (DB2) is 0.9 to 1.1;

the drying shrinkage stress (DS value) of the multifilament yarn A2 is 0.08 cN/dtex or more;

the multifilament yarn A2 is regenerated fibers; and

the multifilament yarn B2 is a cellulose triacetate multifilament yarn that has a mean degree of substitution of 2.76 or more.

6. The fabric according to claim 5 , wherein said fabric contains 20% by weight or more of the composite yarn, and wherein the weight per square meter of the fabric when dry is 100 to 350 g/m 2 , wherein:

the amount of change in air permeability is 10% or more: amount of change in air permeability (%)={[(air permeability at water content of 50% by weight)−(initial air permeability when dry)]/(initial permeability when dry)}×100, and

the initial air permeability when dry is 350 cm 3 /cm 2 /sec or less.

7. The fabric according to claim 5 , wherein said regenerated fibers are rayon or cuprammonium rayon.

8. At least one of a woven fabric and a knit fabric containing composite yarn comprising a multifilament yarn A2 and a multifilament yarn B2, wherein:

the ratio (WA2/DA2) of the yarn length of the multifilament fiber A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn A2 under conditions of 20° C. and 65% humidity (DA2) is 1.02 to 1.30;

the ratio (WA2/DB2) of the yarn length of the multifilament yarn A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn B2 under conditions of 20° C. and 65% humidity (DB2) is 0.9 to 1.1;

the drying shrinkage stress (DS value) of the multifilament yarn A2 is 0.08 cN/dtex or more;

the multifilament yarn A2 is a cellulose-based multifilament yarn obtained by deacetylating cellulose acetate; and

the multifilament yarn B2 is a polyester multifilament yarn having terephthalic acid as a main component thereof and having at least one alkylene glycol as a main glycol component thereof.

9. The fabric according to claim 8 , wherein said alkylene glycol is at least one selected from the group consisting of ethylene glycol, trimethylene glycol and tetramethylene glycol.

10. At least one of a woven fabric and a knit fabric containing composite yarn comprising a multifilament yarn A2 and a multifilament yarn B2, wherein:

the ratio (WA2/DA2) of the yarn length of the multifilament fiber A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn A2 under conditions of 20° C. and 65% humidity (DA2) is 1.02 to 1.30;

the ratio (WA2/DB2) of the yarn length of the multifilament yarn A2 during absorption of moisture and water (WA2) to the yarn length of the multifilament yarn B2 under conditions of 20° C. and 65% humidity (DB2) is 0.9 to 1.1;

the drying shrinkage stress (DS value) of the multifilament yarn A2 is 0.08 cN/dtex or more;

the multifilament yarn A2 is a cellulose-based multifilament yarn obtained by deacetylating cellulose acetate;

the multifilament yarn B2 is a cellulose triacetate multifilament yarn that has a mean degree of substitution of 2.76 or more; and

the multifilament yarns A2 and B2 form the claimed composite yarn by imparting interlacing or plying to the multifilament yarns A2 and B2.