Press jacket and method for the production thereof

1. A press jacket comprising:

at least one polymer layer including or being produced from a polyurethane, said polyurethane being formed from a prepolymer and a cross linking agent,

wherein said prepolymer is a reaction product of phenylene 1,4-diisocyanate (PPDI) and a polyol selected from the group consisting of polyester polyol, polycaprolactone polyol, polyether polyol, polytetramethylene ether glycol (PTMEG), polypropylene glycol (PPG), polyethylene glycol (PEG), polyhexamethylene ether glycol, polycarbonate polyol, polyether carbonate polyol, polybutadiene polyol, and mixtures thereof, and

wherein said cross linking agent comprises:

a first component comprising 1,4-butanediol (BDO) or 1,4-hydroquinone bis(2-hydroxyethyl) ether (HQEE),

a second component comprising at least one aliphatic diamine selected from the group consisting of ethylenediamine (EDA), 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, hexamethylenediamine (HMDA), and mixtures thereof, and

a third component comprising monoethanolamine.

2. The press jacket according to claim 1 , wherein said cross linking agent includes from 60 mol % to 99.9 mol % of said first component.

3. The press jacket according to claim 1 , wherein said cross linking agent includes from 75 mol % to 99.9 mol %, of said first component.

4. The press jacket according to claim 1 , wherein said crosslinking agent includes at most 15 mol % of said second component.

5. The press jacket according to claim 1 , wherein said cross linking agent includes at most 20 mol % of said third component.

6. The press jacket according to claim 1 , wherein said cross linking agent has a fourth component including a catalyst, and said fourth component is selected from the group consisting of:

tertiary amines including 1,4-diazabicyclo[2.2.2]octane (DABCO),

triethylenediamine (TEDA),

triethylamine,

metal compounds,

organometallic compounds including bismuth, bismuth neodecanoate, mercury, aluminum, zirconium, iron, calcium, sodium, potassium, lead, tin, or titanium, and

mixtures thereof.

7. The press jacket according to claim 6 , wherein said cross linking agent includes at most 10 mol % of said fourth component.

8. The press jacket according to claim 6 , wherein said cross linking agent includes at most 5 mol % of said fourth component.

9. The press jacket according to claim 1 , wherein said at least one polymer layer is a radially outermost polymer layer of the press jacket.

10. The press jacket according to claim 1 , which further comprises a reinforcement structure embedded into said at least one polymer layer.

11. The press jacket according to claim 1 , wherein said cross linking agent includes an additional component selected from the group consisting of:

polyester polyol or polycaprolactone polyol;

polyether polyols or polytetramethylene ether glycol (PTMEG),

polypropylene glycol (PPG),

polyethylene glycol (PEG),

polyhexamethylene ether glycol,

polycarbonate polyol,

polyether carbonate polyol,

polybutadiene polyol,

perfluoropolyether polyol,

siliconepolyol, and

mixtures thereof.

12. The press jacket according to claim 1 , wherein said polyol of said prepolymer includes polytetramethylene ether glycol (PTMEG) in a proportion of from 0.01 mol % to 54 mol %.

13. The press jacket according to claim 1 , wherein said polyol of said prepolymer includes polytetramethylene ether glycol (PTMEG) in a proportion of from 44 mol % to 54 mol %.

14. The press jacket according to claim 12 , wherein said polyol of said prepolymer additionally includes a polycarbonate polyol.

15. The press jacket according to claim 1 , wherein said polyol of said prepolymer is exclusively a polycarbonate polyol, except for any possible undesired impurities.

16. A press roll or shoe press roll for a shoe press for the treatment of a web of fibrous material, the press roll comprising at least one press jacket according to claim 1 .

17. A shoe press for the treatment of a web of fibrous paper, paperboard, tissue or pulp material, the shoe press comprising:

a press roll and a counter roll together forming or delimiting a nip; and

said press roll including a surrounding press jacket according to claim 1 .

18. A process for the production of a press jacket, the process comprising the following steps:

a) providing at least one rotatably mounted winding mandrel;

b) providing a cross linking agent containing at least one first component comprising 1,4-butanediol (BDO) or 1,4-hydroquinone bis(2-hydroxyethyl) ether (HQEE), a second component comprising at least one aliphatic diamine selected from the croup consisting of ethylenediamine (EDA), 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, hexamethylenediamine (HMDA), and mixtures thereof, and a third component comprising monoethanolamine;

c) providing a reaction product of phenylene 1,4-diisocyanate (PPDI) and a polyol selected from the croup consisting of polyester polyol, polycaprolactone polyol, polyether polyol, polytetramethylene ether glycol (PTMEG), polypropylene glycol (PPG), polyethylene glycol (PEG), polyhexamethylene ether glycol, polycarbonate polyol, polyether carbonate polyol, polybutadiene polyol, and mixtures thereof;

d) mixing the reaction product and the cross linking agent to produce a polyurethane;

e) spreading a mixture of the reaction-product and the cross linking agent on a surface of the winding mandrel to form at least one polymer layer of the press jacket;

f) hardening the at least one polymer layer; and

g) removing the resultant press jacket from the winding mandrel.

19. The process according to claim 18 , wherein the reaction product of the phenylene 1,4-diisocyanate (PPDI) and the polyol is a prepolymer.

20. A process for using a press jacket for a press or a shoe press, the process comprising treating a web of fibrous paper, paperboard, tissue or pulp material with the press jacket produced according to claim 18 .