Heat-resistant product

1 . A process in which a heat-resistant product having:

a support chosen from a glass fiber and an assembly of glass fibers, and

a coating extending over the outer surface of said support, in a zone called the “protected zone”, said coating comprising particles having a mean size of less than 100 nm and comprising more than 95% by mass of Al 2 O 3 and/or ZrO 2, referred to as “protective particles”, the protective particles covering more than 50% and less than 90% of the protected zone, as percentage by surface area, wherein said process comprises the step of

subjecting said heat-resistant product to a temperature of greater than 600° C. for a duration of greater than 0.5 hours.

2 . The process as claimed in claim 1 , wherein the support is in the form of an optical fiber, a single yarn, an assembled yarn, a felt, a web, a knit, a ribbon, a braid or a woven fabric.

3 . The process as claimed in claim 2 , wherein the support is in the form of a woven fabric including a network of parallel warp yarns and weft yarns transversely crossing said network, at least some of the warp and/or weft yarns being heat-resistant products as claimed in either of the preceding claims .

4 . The process as claimed in claim 1 , wherein the glass fibers constituting the support is a material having an SiO 2 content of greater than or equal to 55%, as percentage by mass based on the oxides.

5 . The process as claimed in claim 4 , wherein the glass fibers constituting the support is a material having, as percentages by mass based on the oxides:

an SiO 2 content of greater than 90% and an Al 2 O 3 content of greater than 0.1% and less than 5%, oxides other than SiO 2 and Al 2 O 3 constituting the remainder to 100%, or

an SiO 2 content of less than 79.9%, an Al 2 O 3 content of greater than 12.5% and less than 32%, and an MgO content of greater than 4% and less than 20%, oxides other than SiO 2, Al 2 O 3 and MgO constituting the remainder to 100%, or

an SiO 2 content of greater than 99.9%.

6 . The process as claimed in claim 1 , wherein the total surface area of the interstices present in the protected zone between the protective particles and having a size of greater than 250 nm represents less than 50% of the total surface area of the interstices of said protected zone, as percentage by surface area.

7 . The process as claimed in claim 1 , wherein the protected zone represents more than 50% of the outer surface area of the support.

8 . The process as claimed in claim 1 , wherein the protective particles cover more than 75% and/or less than 85% of the protected zone, as percentage by surface area.

9 . The process as claimed in claim 1 , wherein the coating comprises, as percentage by mass based on the total mass of the coating, more than 60% protective particles.

10 . The process as claimed in claim 1 , wherein the mean size of the protective particles is greater than 10 nm and less than 70 nm.

11 . The process as claimed in claim 1 , wherein the coating comprises a dry binder comprising

an organic film former in an amount, as percentage by mass based on the mass of the coating, of greater than 0.3% and less than 57%, and/or

an organic coupling agent in an amount, as percentage by mass based on the mass of the coating, of greater than 0.1% and less than 35%, and/or

an organic constituent other than the film former and the coupling agent and chosen from a lubricant, a surfactant, an emulsifier, a wetting agent and mixtures thereof, in an amount, as percentage by mass based on the mass of the coating, of greater than 0.05% and less than 34%.

12 . The process as claimed in claim 1 , the heat-resistant product comprising a layer at least partially covering the coating, said layer comprising one or more materials chosen from:

a polyvinyl alcohol,

a paraffin,

a polytetrafluoroethylene,

a polymethyl methacrylate,

a polyurethane,

a latex,

a resin,

an organic material capable of constituting a dry binder of said coating,

when the coating comprises a dry binder.

13 . The process as claimed in claim 1 , wherein the heat-resistant product is manufactured according to a process comprising the following steps 1) to 3):

1) preparing the support and a suspension comprising a liquid binder and the protective particles;

2) applying said suspension to the support;

3) drying so as to transform the suspension into a coating having a solid form.

14 . The process as claimed in claim 1 , wherein the heat-resistant product is disposed so as to serve

as a heat shield, in particular

of a drive shaft,

of an engine attachment harness,

of an insulation element of an engine

of an actuating cylinder,

of a pipe,

of a system for attachment of said pipe,

of a cable,

of a conveying roller,

of a system for attaching and driving said rollers,

of a nacelle of an engine,

of an engine,

of a suspension structure of an engine

of a thrust reverser

of a fluid supply element of an engine

of a tube in which a fluid circulates

of a seal,

of a valve;

as a sensor, the support being an optical fiber.

15 . The process as claimed in claim 14 , wherein

the drive shaft is a drive shaft of a land vehicle, aircraft or helicopter engine,

the insulation element is an insulation casing of an engine,

the cable is an electric cable or a thermocouple cable,

the conveying roller is for conveying glass sheets,

the nacelle is a nacelle of an aircraft engine,

the heat-resistant product is disposed so as to serve as a heat shield of an engine in a land vehicle, aircraft, helicopter or space rocket engine,

the suspension structure is struts of an aircraft or helicopter engine,

the thrust reverser is a thrust reverser in an aircraft engine,

the fluid supply element of a space rocket engine,

the tube is a tube in which a heat transfer fluid circulates in a reactor,

the optical fiber incorporates at least one Bragg grating.