Core-sheath filaments with a curable composition in the core

Patent metadata

Field	Value
Publication number	US-2023116424-A1
Application number	US-202117904877-A
Country	US
Kind code	A1
Filing date	Mar 16, 2021
Priority date	Mar 31, 2020
Publication date	Apr 13, 2023
Grant date	—

Abstract

A core-sheath filament is provided that includes a curable composition. The curable composition contains an epoxy resin and a photoacid generator. Methods of making the core-sheath filament and methods of using the core-sheath filament for printing and bonding are provided. The core-sheath filaments can be used to form a cured composition having structural bonding performance.

First claim

1 . A core-sheath filament comprising:
a) a core comprising a curable composition comprising curable components comprising
1) an epoxy resin; and
2) a photoacid generator;
b) a sheath surrounding the core, wherein the sheath comprises a thermoplastic material that is non-tacky.

2 . The core-sheath filament of claim 1 , wherein the curable components comprise 30 to 99.99 weight percent epoxy resin and 0.01 to 5 weight percent photoacid generator.

3 . The core-sheath filament of claim 1 , wherein the curable components further comprise a polyol.

4 . The core-sheath filament of claim 1 , wherein the curable components further comprise a film-forming resin.

5 . The core-sheath filament of claim 4 , wherein the film-forming resin comprises ethylene vinyl acetate, a phenoxy resin, a polyester resin, or (meth)acrylate copolymer having pendant hydroxy groups and/or pendant ether groups.

6 . The core-sheath filament of claim 1 , wherein the curable components comprise 30 to 99.99 weight percent epoxy resin, 0 to 30 weight percent polyol, 0 to 70 weight percent film-forming resin, and 0.01 to 5 weight percent photoacid generator based on a total weight of curable components within the curable composition.

7 . The core-sheath filament of claim 1 , wherein the core is a semi-solid.

8 . The core-sheath filament of claim 1 , wherein the core-sheath filament comprises 90 to 99.5 weight percent core and 0.5 to 10 weight percent sheath based on the total weight of the core-sheath filament.

9 . The core-sheath filament of claim 1 , wherein the core-sheath filament has a cross-sectional distance (e.g., diameter) in a range of 1 to 20 millimeters.

10 . The core-sheath filament of claim 1 , wherein the sheath exhibits a melt flow index of less than or equal to 15 grams per 10 minutes as determined using ASTM D1238-13 at 190° C. and with a load (weight) of 2.16 kg.

11 . A method of making a core-sheath filament, the method comprising:
a) forming or providing a core comprising a curable composition comprising curable components comprising
1) an epoxy resin; and
2) a photoacid generator;
b) providing a sheath composition comprising a non-tacky thermoplastic material; and c) surrounding the core with the sheath to form the core sheath filament.

12 . A method of printing and bonding, the method comprising:
a) providing the core-sheath filament of claim 1 ; b) melting the core-sheath filament and blending the sheath with the core to form a blended filament composition; and c) dispensing the blended filament composition through a nozzle onto at least a first portion of a first substrate; and d) positioning either a second substrate or a second portion of the first substrate in contact with the blended filament composition before or after exposing the blended filament composition to ultraviolet and/or visible radiation to activate curing of the curable composition; and e) forming a structural adhesive bond between at least the first portion of the first substrate and either the second substrate or the second portion of the first substrate.

Assignees

• 3M Innovative Properties Company

Inventors

• Shafer Kathleen S
• Chastek Thomas Q
• Napierala Mark E
• Young Jacob D
• Behling Ross E
• West Shaun M
• Thomas John Christopher

Classifications

• C09J163/00

  Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins · CPC title

• C09J2301/202

  the adhesive being in the form of fibres · CPC title

• B29C64/118

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• D01F8/04

  from synthetic polymers · CPC title

• D01F8/16

  with at least one other macromolecular compound obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds as constituent · CPC title