Liquid crystal polymer for mounting x-ray window

Patent metadata

Field	Value
Publication number	US-10991540-B2
Application number	US-201916433202-A
Country	US
Kind code	B2
Filing date	Jun 6, 2019
Priority date	Jul 6, 2018
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

An x-ray window can include an adhesive layer sandwiched between and providing a hermetic seal between a thin film and a housing. The adhesive layer can include liquid crystal polymer. The liquid crystal polymer can be opaque, gas-tight, made of low atomic number elements, able to withstand high temperature, low outgassing, low leakage, able to relieve stress in the x-ray window thin film, capable of bonding to many different materials, or combinations thereof.

First claim

What is claimed is:

1. An x-ray window comprising:
a thin film configured for transmission of x-rays;
a housing;
a pair of adhesive layers including a proximal adhesive layer and a distal adhesive layer, the thin film is sandwiched between the proximal adhesive layer and the distal adhesive layer, and the proximal adhesive layer is located closer to the housing than the distal adhesive layer;
the proximal adhesive layer is sandwiched between and provides a hermetic seal between the thin film and the housing;
the proximal adhesive layer includes an aromatic polyester liquid crystal polymer;
the distal adhesive layer includes liquid crystal polymer;
a ring located at an opposite side of the distal adhesive layer from the thin film, the ring being metallic; and
the proximal adhesive layer, the thin film, and the distal adhesive layer are sandwiched between the ring and the housing.

2. The x-ray window of claim 1 , wherein the liquid crystal polymer of the proximal adhesive layer has shear thinning properties.

3. The x-ray window of claim 1 , further comprising:
a ribbed support structure sandwiched between the thin film and the adhesive layer;
the thin film and the ribbed support structure extending across an aperture of the housing;
the ribbed support structure providing structural support to the thin film across the aperture; and
viscosity of the liquid crystal polymer of the proximal adhesive layer is ≥100,000 cps at 300° C.

4. The x-ray window of claim 1 , wherein a transition temperature of the liquid crystal polymer of the proximal adhesive layer is ≥260° C.

5. The x-ray window of claim 1 , wherein
Young's Modulus of the liquid crystal polymer of the proximal adhesive layer is ≤8 GPa at 25° C.;
tensile strength of the liquid crystal polymer of the proximal adhesive layer is ≥150 MPa and ≤250 MPa at 25° C. for roll-out direction of the liquid crystal polymer of the proximal adhesive layer, transverse to the roll-out direction, or both; and
elongation of the liquid crystal polymer of the proximal adhesive layer is ≥20% and ≤50% at 25° C.

6. The x-ray window of claim 1 , wherein:
≥80% of atoms in the proximal adhesive layer have an atomic number ≤6; and
≥95% of the atoms in the proximal adhesive layer have an atomic number ≤8.

7. The x-ray window of claim 1 , wherein:
the housing has a flange encircling an aperture;
the proximal adhesive layer is located on the flange and has an annular shape encircling the aperture;
1 mm≤W 14 ≤15 mm where W 14 is a width of the proximal adhesive layer on the flange; and
a thickness of the proximal adhesive layer between the thin film and the housing is ≥10 μm and ≤500 μm.

8. The x-ray window of claim 1 , wherein the proximal adhesive layer comprises ≥99% liquid crystal polymer.

9. The x-ray window of claim 1 , wherein the liquid crystal polymer of the proximal adhesive layer includes 4-hydroxybenzaldehyde, 4,4′-biphenol, and terephthalaldehyde.

10. The x-ray window of claim 1 , wherein the liquid crystal polymer of the proximal adhesive layer includes 4-hydroxybenzaldehyde and 6-hydroxy-2-naphthaldehyde.

11. The x-ray window of claim 1 , wherein the liquid crystal polymer of the proximal adhesive layer includes 4-hydroxybenzaldehyde.

12. The x-ray window of claim 1 , wherein the liquid crystal polymer of the proximal adhesive layer includes 6-hydroxy-2-naphthaldehyde.

13. An x-ray window comprising:
a thin film configured for transmission of x-rays;
a housing;
an adhesive layer sandwiched between and providing a hermetic seal between the thin film and the housing;
the adhesive layer including liquid crystal polymer, the liquid crystal polymer including 4-hydroxybenzaldehyde, 6-hydroxy-2-naphthaldehyde, 4,4′-biphenol, ethane-1,2-diol, or combinations thereof.

14. The x-ray window of claim 13 , wherein the liquid crystal polymer includes 4-hydroxybenzaldehyde and 6-hydroxy-2-naphthaldehyde.

15. The x-ray window of claim 13 , wherein the liquid crystal polymer includes 4-hydroxybenzaldehyde, 4,4′-biphenol, and terephthalaldehyde.

16. The x-ray window of claim 13 , wherein the liquid crystal polymer includes 4-hydroxybenzaldehyde.

17. The x-ray window of claim 13 , wherein the liquid crystal polymer includes 6-hydroxy-2-naphthaldehyde.

18. The x-ray window of claim 13 , wherein the liquid crystal polymer includes 4,4′-biphenol.

19. The x-ray window of claim 13 , wherein the liquid crystal polymer includes 4-hydroxybenzaldehyde, terephthalaldehyde, and ethane-1,2-diol.

20. An x-ray window comprising:
a thin film configured for transmission of x-rays;
a housing;
an adhesive layer sandwiched between and providing a hermetic seal between the thin film and the housing, the adhesive layer including a thermotropic liquid crystal polymer; and
the liquid crystal polymer includes 4-hydroxybenzaldehyde and 6-hydroxy-2-naphthaldehyde.

Assignees

• Moxtek Inc

Inventors

• Sommer Jared
• Abbott Jonathan

Classifications

• H01J35/18 Primary

  Windows · CPC title

• H01J2235/183

  Multi-layer structures · CPC title

• C09J167/00

  Adhesives based on polyesters obtained by reactions forming a carboxylic ester link in the main chain (based on polyester-amides C09J177/12; based on polyester-imides C09J179/08); Adhesives based on derivatives of such polymers · CPC title

• H01J5/18

  Windows permeable to X-rays, gamma-rays, or particles · CPC title

• G01T1/16

  Measuring radiation intensity (G01T1/29 takes precedence {; self-powered detectors G01T3/006; using an ionisation chamber filled with a liquid or solid, e.g. frozen liquid, dielectric G01T3/008}) · CPC title