Methods for preparing phthalonitrile coating compositions

Patent metadata

Field	Value
Publication number	US-12030977-B2
Application number	US-202217572750-A
Country	US
Kind code	B2
Filing date	Jan 11, 2022
Priority date	Jan 20, 2021
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

Methods of preparing phthalonitrile coating compositions are provided, including phthalonitrile sprays, phthalonitrile pastes, and phthalonitrile composite films. In embodiments, such a method comprises, heating a phthalonitrile precursor composition comprising a bisphthalonitrile compound to a temperature and for a period of time to form a phthalonitrile prepolymer composition comprising a bisphthalonitrile prepolymer; cooling the phthalonitrile prepolymer composition to ambient temperature and pulverizing the phthalonitrile prepolymer composition to form particles; combining the particles with a liquid medium to form a phthalonitrile solution; optionally, adding an additive to the phthalonitrile solution; and mixing the phthalonitrile solution to form a phthalonitrile coating composition.

First claim

What is claimed is:

1. A method of preparing a phthalonitrile coating composition, the method comprising:
(a) heating a phthalonitrile precursor composition comprising a bisphthalonitrile compound to a temperature and for a period of time to form a phthalonitrile prepolymer composition comprising a bisphthalonitrile prepolymer;
(b) cooling the phthalonitrile prepolymer composition to ambient temperature and pulverizing the phthalonitrile prepolymer composition to form particles;
(c) combining the particles with a liquid medium to form a phthalonitrile solution;
(d) optionally, adding an additive to the phthalonitrile solution; and
(e) mixing the phthalonitrile solution to form a phthalonitrile coating composition,
further comprising after mixing the phthalonitrile solution, storing the mixed phthalonitrile solution for a second period of time at ambient temperature to form the phthalonitrile coating composition as a phthalonitrile paste.

2. The method of claim 1 , wherein the bisphthalonitrile compound comprises an aromatic ether linking group and an aromatic ketone linking group.

3. The method of claim 2 , wherein the aromatic ether linking group is provided by a bisphenol and the aromatic ketone linking group is provided by a benzophenone.

4. The method of claim 1 , wherein the phthalonitrile precursor composition further comprises a curing agent, a phthalonitrile additive, or both.

5. The method of claim 1 , wherein the phthalonitrile precursor composition and the phthalonitrile coating composition is free of a phthalonitrile additive.

6. The method of claim 1 , wherein the temperature is not more than 250° C. and the period of time is not more than 120 minutes in step (a).

7. The method of claim 1 , wherein the bisphthalonitrile prepolymer has a solubility in the liquid medium in a range of from 0.1 g/mL to 5 g/mL at ambient temperature and atmospheric pressure.

8. The method of claim 1 , wherein the liquid medium comprises a solvent having a boiling point of greater than 150° C.

9. The method of claim 1 , wherein the liquid medium comprises two solvents, each having different boiling points.

10. The method of claim 1 , wherein the phthalonitrile solution comprises at least 30 weight % of the liquid medium and not more than 70 weight % of the phthalonitrile prepolymer composition.

11. The method of claim 1 , comprising step (d).

12. The method of claim 11 , wherein the additive is selected from a group consisting of a filler, a dispersant, a flow agent, a cure promoter, and a surfactant and the phthalonitrile solution comprises from 0.001 weight % to 20 weight % of the additive.

13. The method of claim 12 , wherein the additive is not a phthalonitrile additive and is not a non-reactive plasticizer and the phthalonitrile coating composition is free of the phthalonitrile additive and the non-reactive plasticizer.

14. The method of claim 1 , wherein the mixing is carried out at ambient temperature and ambient atmosphere.

15. The method of claim 1 , wherein the mixing is carried out at a speed in a range of from 1000 rpm to 2300 rpm and for a time in a range of from 10 seconds to 30 minutes.

16. The method of claim 1 , wherein the period of time is in a range of from 1 day to 14 days.

17. The method of claim 1 , wherein the phthalonitrile paste has a shear viscosity of greater than 1,000 cps as measured at ambient temperature and 100 Hz.

18. The method of claim 1 , further comprising applying the phthalonitrile coating composition to a surface of a substrate to form a coating thereon.

19. The method of claim 18 , wherein the substrate is an aerospace component.

20. The method of claim 18 , further comprising heating the coating according to a curing profile to form a thermoset polymer.

21. The method of claim 20 , wherein the thermoset polymer is characterized by a glass transition temperature T g in a range of from 200° C. to 500° ° C., a degradation temperature of greater than 450° C., or both.

22. A method of preparing a phthalonitrile coating composition, the method comprising:
(a) heating a phthalonitrile precursor composition comprising a bisphthalonitrile compound to a temperature and for a period of time to form a phthalonitrile prepolymer composition comprising a bisphthalonitrile prepolymer;
(b) cooling the phthalonitrile prepolymer composition to ambient temperature and pulverizing the phthalonitrile prepolymer composition to form particles;
(c) combining the particles with a liquid medium to form a phthalonitrile solution;
(d) optionally, adding an additive to the phthalonitrile solution; and
(e) mixing the phthalonitrile solution to form a phthalonitrile coating composition, wherein the phthalonitrile coating composition does not comprise a curing agent.

Assignees

• Boeing Co

Inventors

• Ventuleth Michael
• Dustin Ashley M

Classifications

• C09D161/00

  Coating compositions based on condensation polymers of aldehydes or ketones (with polyalcohols C09D159/00; with polynitriles C09D177/00); Coating compositions based on derivatives of such polymers · CPC title

• C09D5/021

  Aerosols (aerosol compositions C09K3/30) · CPC title

• C08J2361/00

  Characterised by the use of condensation polymers of aldehydes or ketones; Derivatives of such polymers · CPC title

• B05D1/12

  Applying particulate materials (B05D1/06, B05D1/10 take precedence) · CPC title

• C08J5/244

  using glass fibres · CPC title