Composition, preparation method and application thereof

1. A composition comprising:

(a) a polyurethane polymer which is a reaction product of a reaction mixture comprising:

(a1) a polyisocyanate,

(a2) a compound having an isocyanate-reactive group, which comprises a polyester polyol in an amount of more than 10 wt %, based on a total weight of the compound having an isocyanate-reactive group,

(a3) optionally an emulsifier,

(a4) optionally a solvent, and

(a5) optionally a reactive diluent;

(b) an organic antioxidant in an amount of 0.001 wt % to 1 wt %, based on a total weight of solid components of the composition;

(c) a chelating agent;

(d) water;

(e) optionally a stabilizer;

(f) optionally a crosslinking agent; and

(g) optionally an additive,

wherein the polyurethane polymer (a) has a melting enthalpy of more than 15 J/g at 20 to 100° C., based on a first heating curve measured by DSC according to DIN 65467, or a film formed by drying the composition has a melting enthalpy of more than 15 J/g at 20 to 100° C., based on a first heating curve measured by DSC according to DIN 65467.

2. The composition according to claim 1 , wherein the compound (a2) having an isocyanate-reactive group has a melting enthalpy of more than 15 J/g at 20 to 100° C., based on a first heating curve measured by DSC according to DIN 65467.

3. The composition according to claim 1 , comprising from 50 ppm to 5000 ppm of the organic antioxidant (b), based on the total weight of solid components of the composition.

4. The composition according to claim 1 , comprising an amount of from 0.01 wt % to 0.5 wt % of the organic antioxidant (b), based on the total weight of solid components of the composition.

5. The composition according to claim 1 , comprising an amount of from 0.01 wt % to 1.95 wt % of chelating agent (c), based on the total weight of solid components of the composition.

6. The composition according to claim 1 , wherein the chelating agent (c) is present in the form of a water-soluble chelating agent salt, wherein the water-soluble chelating agent salt meets the following conditions: a pH value of an aqueous solution of the water-soluble chelating agent salt having a content of 4.3*10 −7 mol/g is more than 5.

7. The composition according to claim 6 , wherein the water-soluble chelating agent salt comprises an ethylenediamine tetraacetate, a tartrate, a citrate, a pyrophosphate, a tripolyphosphate, a hexametaphosphate, a gluconate, or a combination thereof.

8. The composition according to claim 1 , wherein the stabilizer (e) comprises a carbodiimide compound, an epoxy compound, an oxazoline compound, an aziridine compound, or a combination thereof in an amount of 0.5 wt % to 10 wt % based on the total weight of solid components of the composition.

9. The composition according to claim 1 , wherein the composition is a coating or an adhesive.

10. A method for producing a composition according to claim 1 , comprising mixing, in any desired manner, the polyurethane polymer (a) or the components for preparing the polyurethane polymer (a), the organic antioxidant (b), the chelating agent (c), water (d), optionally a stabilizer (e), optionally a crosslinking agent (f), and optionally an additive (g).

11. The method according to claim 10 , wherein the polyurethane polymer (a) and water (d) are combined to form an aqueous polyurethane dispersion, and then the organic antioxidant (b), the chelating agent (c), optionally a stabilizer (e), optionally a crosslinking agent (f) and optionally an additive (g) are introduced to the aqueous polyurethane dispersion to obtain the composition.

12. The method according to claim 10 , wherein the chelating agent (c) is added in the form of an aqueous solution.

13. A coating method comprising the steps of applying a composition according to claim 1 to a substrate surface and then curing it.

14. A coated product comprising a substrate and a coating formed by applying a composition according to claim 1 to the substrate.

15. A method for producing a bonded product comprising:

i. applying a composition according to claim 1 to at least one surface portion of a substrate;

ii. heating and drying the substrate surface portion to which the composition is applied; and

iii. contacting the substrate surface portion treated in step ii with another portion of the surface of the substrate or with an additional substrate to obtain the bonded product.

16. The method according to claim 15 , further comprising a step iv between step ii and step iii:

iv. irradiating the substrate surface treated in step ii by means of actinic radiation.

17. The method according to claim 15 , wherein the substrate comprises wood, plastic, metal, glass, textile, alloy, fabric, artificial leather, paper, cardboard, EVA, rubber, dermis, glass fiber, ethylene vinyl acetate copolymer, polyolefin, thermoplastic polyurethane, polyurethane foam, polymer fiber, graphite fiber, or a combination thereof.

18. A bonded product produced by the method according to claim 15 .