Composite system comprising a matrix and scattering elements, process for preparing it and use thereof

Patent metadata

Field	Value
Publication number	US-10563097-B2
Application number	US-201615558672-A
Country	US
Kind code	B2
Filing date	Mar 18, 2016
Priority date	Mar 18, 2015
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A composite system for light diffusion comprises a matrix of a material that is transparent to light; the matrix contains a dispersion of scattering elements having a core that is a nanocluster of inorganic nanoparticles, and a shell comprising silane compounds and dispersing agents; the nanocluster having average dimensions in the range of 20 nm to 300 nm.

First claim

The invention claimed is:

1. A composite system comprising a matrix in which a plurality of scattering elements is dispersed, wherein said matrix is of a material that per se is transparent, said scattering elements have a core, said core having a refractive index that is different from the refractive index of the matrix to provide a scattering of at least a portion of the light transmitted through said system, wherein:
said core comprises a nanocluster of nanoparticles made of inorganic material,
said nanocluster having average dimensions in the range of 20 nm to 300 nm, and
said scattering elements further comprise at least a silane compound and at least a dispersing agent that provide at least part of a shell for said core.

2. A composite system according to claim 1 , wherein said matrix is a polymer matrix.

3. A composite system according to claim 2 , wherein said scattering elements are free from a shell made of the same polymer of the polymer matrix.

4. A composite system according to claim 2 , wherein said matrix is a paint.

5. A composite system according to claim 2 , wherein said polymer matrix is an adhesive material or a film configured for glass lamination.

6. A composite system according to claim 5 , wherein said polymer matrix is selected from ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), and mixtures thereof.

7. A process of glass lamination, wherein a composite system according to claim 2 is used as adhesive material for coupling layers of glass.

8. A composite system according to claim 2 , wherein said matrix is an anti-scratch paint.

9. A composite system according to claim 1 , wherein said inorganic material is selected from TiO 2 , SiO 2 , ZnO, ZrO 2 , Fe 2 O 3 , Al 2 O 3 , Sb 2 SnO 5 , Bi 2 O 3 , CeO 2 .

10. A composite system according to claim 1 , wherein said nanocluster has an average dimension in the range of 50 nm to 200 nm.

11. A composite system according to claim 10 , comprising scattering elements having a core comprising a single nanoparticle and having a shell including at least one silane compound and at least one dispersing agent that provide at least part of a shell for said single nanoparticle core.

12. A composite system according to claim 1 , wherein said at least one silane compound is selected from Triacetoxy(methyl)silane, Di-Tert-butoxydiacet-oxysilane, Phenyltriethoxysilane, (3-Aminopropyl)tris(trimethylsiloxy)silane, N-(n-butyl)-3-amino-propyltrimehoxysilane, N-[3-(Trimethoxysilyl)propyl]aniline, Bis (3-triethoxysilylpropyl) amine, γ-Aminopropyltriethoxysilane, 2-(Allyldimethylsilyl)pyridine, 3-(Trimethoxysilyl)propyl-methacrylate, Vinyltrimethoxysilane, Triphenyl(vinyl)silane, Tris(2-methoxyethoxy)(vinyl)silane, γ-Glycidoxypropyltrimethoxysilane, 3-(Triethoxysilyl)propyl isocyanate, or a mixture thereof.

13. A composite system according to claim 1 , wherein the number of scattering elements within a volume element delimited by a portion of a panel, foil or film surface having an area of 1 m 2 , is N, wherein N≥N min and wherein:

N
min

=

υ
⁢

10

-
29

D
6

·



m
2

+
2

m
2

-
1



2

where υ is a dimensional constant equal to 1 meter 6 , N min is expressed as a number/meter 2 , the effective diameter D, which is given by the scattering element diameter times the matrix refractive index, is expressed in meters and wherein m is equal to the ratio of the refractive index of the nanoparticle core to the refractive index of the matrix material.

14. A composite system according to claim 13 , wherein 2N min ≤N≤13N min .

15. A composite system according to claim 13 , wherein N is in the range 3N min to 10N min .

16. A composite system according to claim 13 , wherein N≈6N min .

17. A composite system according to claim 1 , wherein said nanocluster has an average dimension in the range of 80 nm to 130 nm.

18. A composite system according to claim 1 , wherein the nanocluster is an aggregate of the nanoparticles.

19. A composite system according to claim 1 , wherein single nanoparticles are also dispersed in the matrix.

20. A composite system according to claim 1 , wherein said matrix material does not absorb light.

21. A system comprising a matrix that is a paint configured as a layer on a reflecting element or a mirroring surface, wherein:
a plurality of scattering elements is dispersed in the paint,
the paint is of a material that per se is transparent,
each scattering element has a core that has a refractive index that is different from the refractive index of the matrix to provide a scattering of at least a portion of the light transmitted through the system,
each core comprises a nanocluster of nanoparticles made of inorganic material, the nanocluster having average dimensions in the range of 20 nm to 300 nm, and
the scattering elements further comprise at least a silane compound and at least a dispersing agent that provide at least part of a shell for said nanocluster core.

22. A process for preparing a composite system that is a matrix/nanocluster composite system, wherein a plurality of scattering elements is dispersed in a matrix, wherein the material used for preparing matrix is a material that per se is transparent, the method comprising:
a. selecting at least one inorganic material made of nanoparticles, said nanoparticles having average dimensions in the range of 10-150 nanometers;
b. mixing said material, at least one solvent and at least one dispersing agent, to obtain a dispersion of nanoclusters having average dimensions in the range of 20 to 300 nanometers;
c. adding at least one silane compound to the dispersion obtained in step b) to give a dispersion of scattering elements having an inorganic core that is a nanocluster as per point b) and at least part of a silane shell;
d. dispersing said dispersed scattering elements into the systems from which said matrix will be obtained;
whereby said matrix/nanocluster composite system provides a scattering of at least a portion of the light transmitted through said composite system or through a product containing said system.

23. A process according to claim 22 , wherein said matrix/nanocluster composite system provides a Rayleigh or a Rayleigh-type scattering of at least a portion of the light transmitted through said syste

Assignees

• Coelux Srl

Inventors

• Folcio Franco
• Di Gregorio Antonio Bernardo
• Di Trapani Paolo

Classifications

• B32B2307/41

  Opaque · CPC title

• B32B17/10761

  containing vinyl acetal · CPC title

• C08K9/06

  with silicon-containing compounds · CPC title

• C03C27/10

  with the aid of adhesive specially adapted for that purpose · CPC title

• B32B2307/584

  Scratch resistance · CPC title