Substituted benzimidazole melt additives

Patent metadata

Field	Value
Publication number	US-12467174-B2
Application number	US-202017762228-A
Country	US
Kind code	B2
Filing date	Oct 7, 2020
Priority date	Oct 16, 2019
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Charged polymeric webs, such as electret webs, include a thermoplastic resin and a charge-enhancing additive. The charge-enhancing additive is a substituted-benzimidazole compound. The electret webs may be a non-woven fibrous web or a film. The electret webs are suitable for use as filter media.

First claim

What is claimed is:

1 . An electret web comprising:
a blend of a thermoplastic resin; and a charge-enhancing additive comprising substituted-benzimidazole compound with the general structure of Formula 1:

wherein the groups R 1 , R 2 , R 3 , and R 4 independently comprise a hydrogen atom, an alkyl, an aryl, or a substituted alkyl; and
A comprises a substituted or unsubstituted cyclic or heterocyclic 5- or 6-membered aromatic ring group, wherein the blend is processed by melt extrusion.

2 . The electret web of claim 1 , wherein the web comprises a non-woven fibrous web.

3 . The electret web of claim 1 , wherein the web comprises a film.

4 . The electret web of claim 1 , wherein the A group of Formula 1 comprises a 6-membered cyclic or heterocyclic aromatic group described by the general structure of Formula 2:

wherein X comprises: a —C—R 9 group, wherein R 9 comprises a hydrogen atom, an alkyl, an aryl, a substituted alkyl, hydroxy, or alkoxy; or
a nitrogen atom; and
each R 5 , R 6 , R 7 , and R 8 independently comprises a hydrogen atom, an alkyl, an aryl, or a substituted alkyl; or
a 5-membered cyclic or heterocyclic aromatic group described by the general structure of Formula 3:

wherein Y comprises: a sulfur or nitrogen atom; and
each R 10 and R 11 independently comprises a hydrogen atom, an alkyl, an aryl, or a substituted alkyl.

5 . The electret web of claim 1 , wherein the charge-enhancing additive comprises a compound of Formula 1A, Formula 1B, Formula 1C, or Formula 1D:

6 . An electret filter medium comprising:
a web comprising a blend of:
a thermoplastic resin; and
a charge-enhancing additive comprising substituted-benzimidazole compound with the general structure of Formula 1:

wherein the groups R 1 , R 2 , R 3 , and R 4 independently comprise a hydrogen atom, an alkyl, an aryl, or a substituted alkyl; and
A comprises a substituted or unsubstituted cyclic or heterocyclic 5- or 6-membered ring group, wherein the blend is processed by melt extrusion.

7 . The electret filter medium of claim 6 , wherein the A group of Formula 1 comprises a 6-membered cyclic or heterocyclic aromatic group described by the general structure of Formula 2:

wherein X comprises: a —C—R 9 group, wherein R 9 comprises a hydrogen atom, an alkyl, an aryl, a substituted alkyl, hydroxy, or alkoxy; or
a nitrogen atom; and
each R 5 , R 6 , R 7 , and R 8 independently comprises a hydrogen atom, an alkyl, an aryl, or a substituted alkyl.

8 . The electret filter medium of claim 7 , wherein X comprises:
a —C—R 9 group, wherein R 9 comprises a hydrogen atom; and each R 5 , R 6 , R 7 , and R 8 independently comprises a hydrogen atom.

9 . The electret filter medium of claim 7 , wherein X comprises:
a —C—R 9 group, wherein R 9 comprises a hydroxyl group; and each R 5 , R 6 , R 7 , and R 8 independently comprises a hydrogen atom.

10 . The electret filter medium of claim 7 , wherein X comprises:
a nitrogen atom; and each R 5 , R 6 , R 7 , and R 8 independently comprises a hydrogen atom.

11 . The electret filter medium of claim 6 , wherein the A group of Formula 1 comprises a 5-membered cyclic or heterocyclic aromatic group described by the general structure of Formula 3:

wherein Y comprises: a sulfur or nitrogen atom; and
each R 10 and R 11 independently comprises a hydrogen atom, an alkyl, an aryl, or a substituted alkyl.

12 . The electret filter medium of claim 11 , wherein
Y comprises: a sulfur atom; and each R 10 and R 11 independently comprises a hydrogen atom.

13 . The electret filter medium of claim 6 , wherein the charge-enhancing additive comprises a compound of Formula 1A, Formula 1B, Formula 1C, or Formula 1D:

14 . The electret filter medium of claim 6 , wherein the thermoplastic resin comprises:
polyolefin; polyvinyl chloride; polystyrene; polycarbonate; or polyester.

15 . The electret filter medium of claim 6 , wherein the charge-enhancing additive comprises 0.02-5.0% by weight of the web.

16 . The electret filter medium of claim 6 , wherein the web contains an electrostatic charge, wherein the charge is imparted through corona treatment, hydrocharging, or a combination thereof.

17 . The electret filter medium of claim 6 , wherein the web further comprises at least one additional additive selected from pigments, light stabilizers, nucleating agents, primary and secondary antioxidants, metal deactivators, hindered amines, hindered phenols, fatty acid metal salts, triester phosphites, phosphoric acid salts, fluorine-containing compounds and combinations thereof.

Assignees

• 3M Innovative Properties Company

Inventors

• Li Fuming B
• Schultz Nathan E
• Brandner John M
• Sebastian John M

Classifications

• B03C3/28

  Plant or installations without electricity supply, e.g. using electrets · CPC title

• D04H3/16

  with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion · CPC title

• D04H3/007

  Addition polymers · CPC title

• B01D39/1692

  Other shaped material, e.g. perforated or porous sheets · CPC title

• B01D39/163

  sintered or bonded · CPC title