Charge-modified particles and methods of making the same

Patent metadata

Field	Value
Publication number	US-11820844-B2
Application number	US-201916980175-A
Country	US
Kind code	B2
Filing date	Mar 19, 2019
Priority date	Mar 22, 2018
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A charge-modified particle comprising the inorganic core and a shell surrounding the inorganic core, wherein the shell comprises a copolymer comprising monomeric units corresponding to free-radically polymerizable monomers, and wherein at least one of the monomeric units comprises a substituted benzotriazolylphenolate salt. Methods of making the charge-modified particle by admicellar polymerization are also disclosed.

First claim

What is claimed is:

1. A charge-modified particle comprising an inorganic core and a shell surrounding the inorganic core, wherein the shell comprises a copolymer comprising monomeric units corresponding to free-radically polymerizable monomers, and wherein at least one of the monomeric units comprises a substituted benzotriazolylphenolate salt.

2. The charge-modified particle of claim 1 , wherein the shell is covalently crosslinked.

3. The charge-modified particle of claim 1 , wherein the shell further comprises a surfactant.

4. The charge-modified particle of claim 1 , wherein at least a portion of the free-radically polymerizable monomers are hydrophobic.

5. The charge-modified particle of claim 1 , wherein the copolymer is acrylic.

6. The charge-modified particle of claim 1 , wherein the copolymer is a copolymer of styrene and at least one hydrophobic (meth)acrylic monomer.

7. The charge-modified particle of claim 1 , wherein the substituted benzotriazolylphenolate salt is represented by the formula

wherein
Z is an alkylene group having from 1 to 8 carbon atoms;
R is H or methyl; and
M + is an alkali metal cation or a quaternary ammonium ion having from 4 to 50 carbon atoms.

8. The charge-modified particle of claim 1 , wherein the inorganic core comprises boron nitride.

9. A plurality of charge-modified particles according to claim 1 .

10. The plurality of charge-modified particles according to claim 9 , further comprising a flow additive comprising at least one of fumed or precipitated silica, fumed or precipitated alumina, silica nanoparticles, or alumina nanoparticles.

11. A composition comprising the plurality of charge-modified particles of claim 9 retained in an organic binder material.

12. A method comprising electrostatically coating the composition of claim 11 onto a substrate.

13. The method of claim 12 wherein the substrate comprises a curable make layer precursor disposed on a backing.

14. The method of claim 12 , wherein the charge-modified particles comprise boron nitride.

15. A method of making charge-modified particles, the method comprising:
providing an aqueous mixture of inorganic particles and a surfactant;
adding at least one hydrophobic free-radically polymerizable monomer and a free-radically polymerizable substituted benzotriazole phenol to the aqueous mixture to form a free-radically polymerizable mixture, wherein at least a portion of the at least one hydrophobic free-radically polymerizable monomer is disposed in a surfactant bilayer that is disposed on the particles;
adding a free-radical initiator to the free-radically polymerizable mixture thereby polymerizing at least a portion of the hydrophobic free-radically polymerizable monomer to form the charge-modified particles, each comprising the inorganic core and a shell surrounding the inorganic core, wherein the shell comprises a copolymer comprising monomeric units corresponding to the at least one hydrophobic free-radically polymerizable monomer and the free-radically polymerizable substituted benzotriazole phenol; and
converting at least a portion of the monomeric units corresponding to the free-radically polymerizable substituted benzotriazole phenol into a substituted benzotriazolylphenolate salt.

16. The method of claim 15 , wherein the shell comprises an organic polymer.

17. The method of claim 16 , wherein the organic polymer comprises an acrylic polymer.

18. The method of claim 15 , wherein the at least one hydrophobic free-radically polymerizable monomer comprises a monomer having at least two free-radically polymerizable groups.

19. The method of any claim 18 , wherein the monomer having at least two free-radically polymerizable groups comprises at least one of divinylbenzene, 1,6-hexanediol di(meth)acrylate, 2,4-dimethyl-1,5-pentanediol di(meth)acrylate, 2-ethyl-4-methyl-1,5-pentanediol di(meth)acrylate, 2,4-di ethyl-1,5-pentanediol di(meth)acrylate, 2-ethyl-4-propyl-1,5-pentanediol di(meth)acrylate, 2,4-dipropyl-1,5-pentanedioldi(meth)acrylate, 2-isopropyl-4-methyl-1,5-pentanediol di(meth)acrylate, 2-ethyl-4-isopropyl-1,5-pentanediol di(meth)acrylate, 2,4-diisopropyl-1,5-pentanediol di(meth)acrylate, 2-isopropyl-4-propyl-1,5-pentanediol di(meth)acrylate, 1,1,1-trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, bis[2-(methacryloyloxy)ethyl] phosphate, or dipentaerythritol penta(meth)acrylate.

20. The method of claim 15 , further comprising isolating the charge-modified particles.

21. The method of claim 15 , wherein the shell further comprises the surfactant.

22. The method of claim 15 , wherein the at least one hydrophobic free-radically polymerizable monomer comprises at least one of styrene, N-(n-octadecyl) (meth)acrylamide, t-amyl (meth)acrylate, t-butyl (meth)acrylate, cyclohexyl (meth)acrylate, isodecyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, N-(n-dodecyl)(meth)acrylamide, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, N-(tert-octyl)(meth)-acrylamide, 2-phenoxyethyl (meth)acrylate, phenyl (meth)acrylate, 2-phenylethyl (meth)acrylate, stearyl (meth)acrylate, undecyl (meth)acrylate, isobornyl (meth)acrylate, tridecyl (meth)(meth)acrylate, 1,4-butanediol di(meth)acrylate, 2-ethylhexyl (meth)acrylate, or neopentyl glycol di(meth)acrylate.

23. The method of claim 15 , wherein the substituted benzotriazolylphenolate salt is represented by the formula

wherein
Z is an alkylene group having from 1 to 8 carbon atoms;
R is H or methyl; and
M + is an alkali metal cation or a quaternary ammonium ion having from 4 to 50 carbon atoms.

24. The method of claim 15 , wherein the inorganic particles comprise boron nitride.

25. The method of claim 15 , further comprising adding a flow additive to the inorganic particles before adding the at least one hydrophobic free-radically polymerizable monomer and free-radically polymerizable substituted benzotriazole phenol to the aqueous mixture, wherein the flow additive comprises at least one of fumed or precipitated silica, fumed or precipitated alumina, silica nanoparticles, or alumina nanoparticles.

Assignees

• 3M Innovative Properties Company

Inventors

• Schultz Nathan E
• Belkin Mikhail A
• Hoffdahl Gerry A
• Baran Jr Jimmie R
• Wu Tien T

Classifications

• C08F220/36 Primary

  containing oxygen in addition to the carboxy oxygen {, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate} · CPC title

• B05D1/007

  using an electrostatic field (B05D1/02 - B05D1/16 take precedence) · CPC title

• B24D3/28

  Resins {or natural or synthetic macromolecular compounds (B24D3/22 takes precedence)} · CPC title

• B24D3/34

  characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties · CPC title

• B32B27/14

  next to a particulate layer · CPC title