Soft hand copolyamide composition

Abstract

Composition comprising, on a weight basis, the total being equal to 100%: from 98% to 100% of at least one copolyamide bearing amide units and polyether units, having a melting point (T.sub.m) from about 90 to about 150 C., in particular from about 100 C. to about 125 C., and having a flexural modulus of less than 100 MPa, as determined according to standard ISO 178 (2010); from 0 to 2% of at least one additive chosen from stabilizers and dyes, or a mixture thereof,
for the manufacture of a heat-sensitive adhesive, in particular a veil, a film, granules, a filament, a grate, a powder or a suspension.

Claims

1. A method of using a heat-sensitive adhesive in the textile industry, comprising the steps of: a) forming a heat-sensitive adhesive composition of a HMA (hot-melt adhesive), consisting of on a weight basis, the total being equal to 100%: from 98% to 100% of at least one copolyamide bearing amide units and polyether units, having a melting point (T.sub.m) from about 100 C. to about 125 C., and having a flexural modulus less than 100 MPa, as determined according to standard ISO 178 (2010); the said amide unit being 6/12, with a weight proportion of the long chain aliphatic repeat unit C12 of the amide unit being from 70% to 80%, the polyether units being derived from polytetramethtylene glycol (PTMG), the weight proportion of polyether units in the copolyamide being greater than 50%, from 0 to 2% of at least one additive chosen from stabilizers and dyes, or a mixture thereof wherein said heat-sensitive adhesive is selected from the group consisting a veil, a film, in granules, a filament, and a grate; b) melting said heat-sensitive composition by heating; c) applying said adhesive to two parts of a textile; d) allowing said heat-sensitive adhesive composition to cool.

2. The method of claim 1, wherein said method results in end-to-end bonding of the two parts of a textile.

3. The method of claim 1, wherein said Method results in two parts of a textile joined together without stitching.

4. The method according to claim 1, said adhesive having a thickness of from 5 to 30 micrometers for a veil, 20 to 100 micrometers for a film and 10 to 50 micrometers for a grate, and said adhesive having an adherence to a textile, of greater than 3 N/cm, as determined by the T peel test at 100 mm/min.

5. The method according to claim 4, said adhesive having an adherence to a textile, of greater than 5 N/cm, as determined by the T peel test at 100 mm/min.

6. The method according to claim 4, wherein the adherence is determined at a lamination temperature of from 120 to 180 C.

7. The method according to claim 1, having a loss of adherence after at least two washes at 40 C. from about 2% to about 18%.

8. The method according to claim 1 having a loss of adherence after at least two washes at 60 C. from about 2% to about 30%.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows the initial adhesion (or adherence) force in N/cm as a function of the lamination temperature, of films of 30 m or 60 m of TPU (1: Tm=100 C., 2: Tm=120 C., 3: Tm=150 C.) or of the invention (6/12/PTMG (1000/1000, MW amide units and polyether units, respectively): composition 1, Tm=110 C.) laminated on cotton (cotton: 90%, polyester: 10%) or Lycra at various temperatures.

(2) From left to right:

(3) Lamination temperature=120 C.: 14 N/cm: 6/12/PTMG and 4 N/cm: TPU1 (films of 30 m on cotton);

(4) Lamination temperature=120 C.: 12 N/cm: 6/12/PTMG and 6 N/cm: TPU1 (films of 30 m on Lycra);

(5) Lamination temperature=140 C.: 11 N/cm: 6/12/PTMG and 2 N/cm: TPU2 (films of 60 m on cotton);

(6) Lamination temperature=160 C.: 16 N/cm: 6/12/PTMG, 4 N/cm: TPU2 and 2 N/cm: TPU3 (films of 60 m on cotton);

(7) Lamination temperature=180 C.: 22 N/cm: 6/12/PTMG and 3 N/cm: TPU3 (films of 60 m on cotton).

(8) Irrespective of the film thickness, the fabric used and the lamination temperature, the adhesion (or adherence) of the films of the invention is very markedly superior to that of the three TPUs used.

(9) FIG. 2 shows the resistance to washing at 40 C. of films of 60 m of TPU (2: Tm=120 C., 3: Tm=150 C.) or of the invention (6/12/PTMG (1000/1000 MW amide units and polyether units, respectively): composition 1, Tm=110 C.) on cotton (cotton: 90%, polyester: 10%) as a function of the lamination temperature.

(10) From left to right:

(11) Lamination temperature=140 C.: 82%: 6/12/PTMG and 50%: TPU2;

(12) Lamination temperature=160 C.: 98%: 6/12/PTMG, 79%: TPU2 and 50% TPU3;

(13) Lamination temperature=180 C.: 98%: 6/12/PTMG and 67%: TPU3.

(14) The resistance to washing at 40 C. of the films of the invention is very markedly superior to that of the TPUs irrespective of the lamination temperature.

(15) FIG. 3 shows the resistance to washing at 60 C. of films of 60 m of TPU (1: Tm=100 C., 2: Tm=120 C., 3: Tm=150 C.) or of the invention (6/12/PTMG (1000/1000, MW amide units and polyether units, respectively): composition 1, Tm=110 C.) on cotton (cotton: 90%, polyester: 10%) or Lycra as a function of the lamination temperature.

(16) Lamination temperature=120 C.: 91%: 6/12/PTMG and 17%: TPU1 (films of 30 m on cotton);

(17) Lamination temperature=120 C.: 89%: 6/12/PTMG and 71: TPU1 (films of 30 m on Lycra);

(18) Lamination temperature=140 C.: 73%: 6/12/PTMG and 25%: TPU2 (films of 60 m on cotton);

(19) Lamination temperature=160 C.: 75%: 6/12/PTMG, 66%: TPU2 and 25% TPU3 (films of 60 m on cotton);

(20) Lamination temperature=180 C.: 96%: 6/12/PTMG and 60%: TPU3 (films of 60 m on cotton).

(21) The resistance to washing at 60 C. of the films of the vention is very markedly superior to that of the TPUs irrespective of the lamination temperature, the textile used or the thickness of the film.

EXAMPLES

Example 1

Compositions of the Invention

(22) Compositions are prepared according to the techniques known to those skilled in the art.

(23) The melting point is measured by DSC (differential scanning calorimetry) according to standard 11357-3 (2013) or according to DIN 53736, Volume B (visual determination of the melting point of semi-crystalline polymers) optically using a heating bench and a microscope.

(24) Composition 1: 6/12/PTMG (1000/1000, PA6/PA12 (30/70). DSC 1.sup.st heating: 114.8 C. The composition is detailed in Table I below:

(25) TABLE-US-00007 TABLE I Starting material Weight Unit Sebacic acid 4.63 kg PTMG1000 22.46 kg Lactam 6 5.40 kg Lactam 12 12.60 kg Water 4.00 kg Anti-UV 225.00 g Antioxidant 135.00 g Zirconium 67.50 g butoxide

(26) Composition 2: 6/12/PTMG (1000/1000, PA6/PA12 (25/75)).

(27) DSC 1.sup.st heating: 124.6 C. The composition is detailed in Table II below:

(28) TABLE-US-00008 TABLE II Starting material Weight Unit Sebacic acid 4.63 kg PTMG1000 22.46 kg Lactam 6 4.50 kg Lactam 12 13.50 kg Water 4.00 kg Anti-UV 225.00 g Antioxidant 135.00 g Zirconium 67.50 g butoxide

(29) Composition 3: 6/11/12/PTMG (1000/1000, PA6/PA11/PA12 (20/10/70)). DSC 1.sup.st heating: 116.5 C. The composition is detailed in Table III below:

(30) TABLE-US-00009 TABLE III Starting material Weight Unit Sebacic acid 4.63 kg PTMG1000 22.46 kg Lactam 6 3.60 kg Amino 11 1.80 Lactam 12 12.60 kg Water 4.00 kg Anti-UV 225.00 g Antioxidant 135.00 g Zirconium 67.50 g butoxide

Example 2

Test of Adhesion (or Adherence) of the Compositions of the Invention

(31) Lamination machine: model HP-450M,MS Pressure: 1.0 kg/cm.sup.2 Bonding time: 25 sec Peeling machine: Hongda Tensometer Peel test at 100 mm/min Type of HMA 6/12/PTMG (composition 1) 3 different types of aliphatic or aromatic TPU: TPU1: Tm=100 C., TPU2: Tm=120 C., TPU3: Tm=150 C., sold by Bayer under the brand name Desmapan or BASF under the brand name Elastollan. Types of textiles: Cotton (cotton 90%, polyester 10%) Lycra The adhesion (or adherence) tests are presented in FIG. 1.

Example 3

Resistance to Washing

(32) The various heat-sensitive adhesives are subjected to two machine washes for 1 hour 30 minutes for each wash and then to drying.

(33) The washing tests are presented in FIGS. 2 and 3.

(34) Comparison of the Heat-Sensitive Adhesive Properties

(35) Table IV presents the comparison of the properties of a heat-sensitive adhesive consisting of a composition of the invention (6/12/PTMG: 1000/1000): composition 1 with those of TPU or of a standard copolyamide.

(36) TABLE-US-00010 TABLE IV PROPERTIES TPU Standard CoPA Composition 1 Soft hand ++ + Resistance to Up to 40 C. From 40 C. to 90 C. Up to 60 C. washing Yellowing + + Implementation + +

(37) means that the product does not have the property under consideration.

(38) + means that the product has the property under consideration in satisfactory manner.

(39) ++ means that the product has the property under consideration in an excellent manner.

(40) The soft hand determines the flexibility of the compound.

(41) The comparison of the observed properties shows that only the adhesive of the invention has the four properties described in this figure.

(42) Table V shows the comparison of the major properties of various heat-sensitive adhesives.

(43) TABLE-US-00011 TABLE V 6/6.12/11/PEG.12 6/12/PTMG at 25/20/25130 (1000/1000) PROPER- Standard Comparative Composition TIES TPU CoPA composition 1 Modulus 5 300 200 90 at 23 C. Resistance to Up to From Up to 40 C. Up to 60 C. washing 40 C. 40 C. to 90 C. Tm 80 to 80 to 100 C. 110 C. 150 C. 135 C.

(44) The TPUs have a suitable modulus but are not resistant to washing. Moreover, they are difficult to implement for the preparation of films.

(45) The standard CoPAs show very good resistance to washing but have an excessively high modulus for the heat-sensitive adhesive application.

(46) 6/6.12/11/PEG.12 shows poor resistance to washing and moreover has an excessively high modulus for the heat-sensitive adhesive application.

(47) Only the compounds of the invention of CoPA/PTMG type have both satisfactory modulus and wash-resistance values.