TRANSPARENCY REPAIR SYSTEM

Abstract

The present invention provides a composition as well as a method for repairing deep scratches, gouges, etc. and which is particularly useful for aircraft and aerospace transparency repair. The composition is a polishable two-part, solvent-free, composition polyurethane coating for repairing the transparencies and which, after application, cures to a thermoset polyurethane.

Claims

1. A transparency repair composition comprising: a two-part system of: (a) a hydroxy-terminated polyol, a light stabilizer and a catalyst defining Part A; (b) an aliphatic polyisocyanate defining Part B; and Wherein, when cured, provides a thermoset polyurethane.

2. The repair composition of claim 1, wherein Part A further includes a chain extender comprising a short chain diol.

3. The composition of claim 1, wherein the hydroxy-terminated polyol is either a polyether or polyester polyol having at least two primary hydroxy groups and mixtures thereof.

4. The composition of claim 2, wherein the hydroxy-terminated polyol is a polyester triol terminated by primary hydroxyl groups.

5. The composition of claim 4, wherein the hydroxy-terminated polyol is an aliphatic polyester primary hydroxy-terminated triol.

6. The composition of claim 5, wherein the light stabilizer is a liquid hindered amine light stabilizer.

7. The composition of claim 1, wherein the catalyst is a tin-based catalyst.

8. The composition of claim 1, wherein the diisocyanate is an aliphatic diisocyanate.

9. The composition of claim 1, wherein the first part and second parts are present in respect to weight ratio to about 1:1 to about 1:3.

10. A method for preparing an aerospace or aircraft transparency repair kit comprising blending together at ambient conditions with stirring for a period of time ranging about twenty seconds to about thirty seconds, the two-part repair kit being the components of claim 1.

11. A method for repairing an aerospace or aircraft transparency comprising: (a) applying to the transparency the two-part component system of claim 1, (b) thereafter, placing an FEP release film thereover, (c) smoothing the FEP film over the repair composition and, (d) after about two hours removing the film and (e) allowing the coating to cure.

Description

EXAMPLE

[0041] An initial master batch of the Part A component is made by adding together at ambient conditions the resins of Part A in a polyethylene bottle. The bottle is roll mixed for a minimum of two hours to obtain Master Batch A.

[0042] A repair kit is prepared by charging 2.5 parts of Master Batch A into a syringe (Part A syringe). Next, 4.5 parts of a diisocyanate is charged into another syringe (Part B). The two syringes are, then, charged into a suitable reaction vessel such as a mixing dish at room temperature and pressure and mixed for about 20 seconds until the resin is clear.

[0043] Thereafter, the coating is brushed into a damaged area using a painter's brush, as an applicator. An FEP film is, then, placed over the repair area.

[0044] Pressure is thereafter applied with a squeegee to smooth out the repaired area. After about two hours, the film is removed thereby revealing the repaired area.

[0045] Table I below sets forth the ingredients and amounts thereof used to prepare the repair resin system.

TABLE-US-00001 AMOUNT, pbw Batch A Polyester polyol*(1) 88.0 1,4 butanediol 10.5 Tinuvin 1.0 Dibutyltin Dilaurate 0.5 PART B Polyisocyanate*(2) 100 (1)CAPA 3091 (2)DESMODUR N-3300

[0046] When applied to a deeply scratched transparency in the above-described manner a repaired transparency is obtained.

[0047] It should be noted that while the present invention has been described with reference to aircraft and aerospace transparencies it is equally applicable to other plastic transparencies.

[0048] Having thus described the invention, what is claimed is: