Filament winding processes using polyurethane resins and systems for making composites

1. A process for making a composite, comprising:

a) impregnating a plurality of aligned continuous fibers, by passing the aligned fibers through a channel having a polyurethane-forming composition disposed therein, wherein the aligned fibers are contacted with the composition as the fibers pass through the channel; and

b) winding the impregnated aligned fibers about a mandrel which pulls the aligned fibers through the channel,

wherein the polyurethane-forming composition comprises a mixture of components comprising:

(i) an isocyanate-functional component comprising an organic polyisocyanate, and (ii) an isocyanate-reactive component comprising:

(A) at least 50% by weight, based on total weight of (ii), of an amine-initiated polyether polyol having a functionality of at least 3 and a number average molecular weight of from 100 gram/mole to 4000 gram/mole, and

(B) 10 to 50% by weight, based on total weight of (ii), of a hydroxyl-functional hydrophobic vegetable oil or hydroxyl-functional hydrophobic modified vegetable oil,

with the proviso that:

(1) the isocyanate-reactive component comprises no more than 10% by weight of a polyether polyol produced from an initiator other than an amine, based on the total weight of polyether polyol in the polyurethane-forming composition,

or

(2) the isocyanate-reactive component comprises no more than 35% by weight of a polyether polyol produced from an initiator other than an amine, based on the total weight of polyether polyol in the polyurethane-forming composition, and the isocyanate-reactive component comprises at least 5% by weight, based on the total weight of the isocyanate-reactive component of the polyurethane-forming composition, of a non-reactive hydrophobic oil.

2. The process of claim 1 , wherein the polyurethane-forming composition has a viscosity, at 25° C. of no more than 1000 mPa·s for at least 30 minutes after mixture of the isocyanate-functional component and the isocyanate-reactive component.

3. The process of claim 1 , wherein the isocyanate-functional component and the isocyanate-reactive component are mixed in amounts such that the NCO Index is at least 90.

4. The process of claim 1 , wherein the isocyanate-functional component comprises a modified polymeric diphenylmethane diisoceyanate prepolymer.

5. The process of claim 4 , wherein the a modified polymeric diphenylmethane diisocyanate prepolymer has an NCO content of 31.8-32.6 wt % and a viscosity at 25° C. of 30-50 mPa·s.

6. The process of claim 1 , wherein the amine-initiated polyether polyol having a functionality of at least 3 comprises a tri-functional polyether polyol and/or a tetra-functional polyether polyol.

7. The process of claim 6 , wherein the polyurethane-forming composition comprises at least 50% by weight of an amine-initiated polyether triol, based on the total weight of amine-initiated polyether polyol in the composition.

8. The process of claim 6 , wherein the polyurethane-forming composition comprises:

(1) a tri-functional polyether polyol, and

(2) a tetra-functional polyether polyol,

wherein the weight ratio of (1) to (2) in the composition is at least 1:2.

9. The process of claim 6 , wherein the polyurethane-forming, composition comprises

(1) an amine-initiated tetra-functional polyether polyol that has a number average molecular weight of from 1000 to 4000, and/or

(2) an amine-initiated tetra-functional polyether polyol that has a number average molecular weight of from 100 to 600.

10. The process of claim 9 , wherein (1) is present in an amount of 75 to 85% by weight, based on the total weight of amine-initiated tetra-functional polyether polyol used in the polyurethane-forming composition, and (2) is present in an amount of 15 to 25% by weight, based on the total weight of amino-initiated tetra-functional polyether polyol used the polyurethane-forming composition.

11. the process of claim 1 , wherein at least some of the amine-initiated polyether polyol has an overall renewables content of from 20% to 85%.

12. A process for making a composite, comprising:

a) impregnating a plurality of aligned continuous fibers by passing the aligned fibers through a channel having a polyurethane-forming composition disposed therein, wherein the aligned fibers are contacted with the composition as the fibers pass through the channel; and

b) winding the impregnated aligned fibers about a mandrel which pulls the aligned fibers through the channel,

wherein the polyurethane-forming composition comprises a mixture of components comprising:

(i) an isocyanate-functional component comprising an organic polyisocyanate, and ii) an isocyanate-reactive component comprising:

(A) at least 50% by weight, based on total weight of (ii), of an amine-initiated polyether polyol having a functionally of at least 3 and a number average molecular weight of from 100 gram/mole to 4000 gram/mole, and

(B) 10 to 50% by weight, based on total weight of (ii), of a hydroxyl-functional hydrophobic vegetable oil or hydroxyl-functional hydrophobic modified vegetable oil,

with the proviso that the isocyanate-reactive component comprises no more than 10% by weight of a polyether polyol produced from an initiator other than an amine, based on the total weight of polyether polyols in the polyurethane-forming composition.

13. The process of claim 1 , wherein the hydroxyl-functional hydrophobic vegetable oil and/or hydroxyl-functional hydrophobic modified vegetable oil comprises castor oil, a hydroxylated soybean oil and/or a cashew oil-based polyol.

14. The process of claim 13 , wherein the hydroxyl-functional hydrophobic vegetable oil comprises a cashew oil-based polyol haying a viscosity at 25° C. of less than 9000 mPa·s, an OH number of 175 to 550, and a functionality of from 2 to 5.

15. The process of claim 1 , wherein the polyurethane-forming composition comprises a non-reactive hydrophobic oil having a viscosity of 10 to 50 Saybolt universal seconds at 37.8° C. measured according to ASTM D2161.

16. The process of claim 15 , wherein the non-reactive hydrophobic oil is present in an amount of at least 5% by weight and up to 20% by weight, based on the total weight of the isocyanate-reactive component of the polyurethane-forming composition.