Microspheres
The present invention relates to microspheres and to their use, preferably as laser absorbing additive, and to a process for their production.
1. A composition comprising microsphere core-shell particles dispersed in a polyolefin carrier, wherein the core of each of the microsphere core-shell particles contains only one laser absorber which is Bi 2 O 3 or BiOCl and contains at least one non-olefinic polymer compound, and the shell of each of the microsphere core-shell particles contains at least one compatibilizer,
which compatibilizer is
a functionalized polymer that is a copolymer of ethylene and glycidyl methacrylate (ethylene-GMA), or
a grafted polyolefin, or
styrene-ethylene/butylene-styrene (SEBS), and
wherein the laser absorber represents 20-90 wt. % of the microsphere.
2. The composition according to claim 1 , wherein the laser absorber is BiOCl.
3. The composition according to claim 1 , wherein the laser absorber is Bi 2 O 3 .
4. The composition according to claim 1 , wherein the non-olefinic polymer is color forming.
5. The composition according to claim 1 , wherein the non-olefinic polymer is polyphenylenoxide/polystyrene (PPO/PS) or polybutylene terephthalate (PBT).
6. The composition according to claim 1 , wherein the compatibilizer is a functionalized polymer that is the copolymer of ethylene and glycidyl methacrylate (ethylene-GMA).
7. The composition according to claim 1 , wherein the compatibilizer is the grafted polyolefin.
8. The composition according to claim 7 , wherein the compatibilizer is a grafted polyethylene or grafted polypropylene.
9. The composition according to claim 7 , wherein the compatibilizer is maleic anhydride grafted polyethylene or maleic grafted polypropylene.
10. The composition according to claim 1 , wherein the compatibilizer is the styrene-ethylene/butylene-styrene (SEBS).
11. The composition according to claim 1 , wherein said polyolefin carrier is a linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), low-density polyethylene (LDPE) or metallocene polyethylene (m-PE).
12. The composition according to claim 1 , wherein the core, the shell and/or the polyolefin carrier contain(s) additives, which are one or more of reinforcing materials, nano-fillers, pigments, dyes, colorants, fillers, processing aids, stabilizers, antioxidants, plasticizers, impact modifiers, flame retardants, mold release agents or foaming agents.
13. The composition according to claim 1 , wherein the microsphere core-shell particles have a mean particle size of 0.5-3.0 microns.
14. The composition according to claim 1 , wherein the composition comprises
25-70
wt. % of Bi 2 O 3
(=core)
8-25
wt. % of PPO/PS or PBT
(=core)
0.5-7.5
wt. % of grafted polyolefin
(=shell)
20-50
wt. % of polyolefin
(=polyolefin carrier)
0-5
wt. % of additives
based on the total weight of the composition, wherein the wt. % are in total ≤100%.
15. The composition according to claim 1 , wherein the composition comprises
25-70
wt. % of Bi 2 O 3
(=core)
8-25
wt. % of PPO/PS or PBT
(=core)
0.5-7.5
wt. % of SEBS
(=shell)
20-50
wt. % of polyolefin
(=polyolefin carrier)
0-5
wt. % of additives
based on the total weight of the composition, wherein the wt. % are in total ≤100%.
16. The composition according to claim 1 , wherein the composition comprises
25-70
wt. % of Bi 2 O 3
(=core)
8-25
wt. % of PPO/PS or PBT
(=core)
0.5-7.5
wt. % of ethylene-GMA
(=shell)
20-50
wt. % of polyolefin
(=polyolefin carrier)
0-5
wt. % of additives
based on the total weight of the composition, wherein the wt. % are in total ≤100%.
17. The composition according to claim 1 , wherein the microspheres have been produced by reactive extrusion.
18. The composition according to claim 1 , wherein the laser absorber represents 50-90 wt. % of the cores of the microsphere and the non-olefinic polymer represents 10-50 wt. % of the cores of the microsphere.
19. A laser-markable composition comprising the composition according to claim 1 and a matrix polymer, thereby forming the laser-markable composition.
20. The laser-markable composition according to claim 19 , wherein the amount of Bi 2 O 3 or BiOCl is 0.125-0.5 wt. % based on the laser-markable composition.
21. A laser-markable and laser-weldable composition comprising a matrix polymer and at least one microsphere core-shell particle, wherein the core of the microsphere core-shell particle contains only one laser absorber which is Bi 2 O 3 or BiOCl and at least one non-olefinic polymer compound, and the shell of the microsphere core-shell particle contains at least one compatibilizer,
which compatibilizer is
a functionalized polymer that is a copolymer of ethylene and glycidyl methacrylate (ethylene-GMA), or
a grafted polyolefin, or
styrene-ethylene/butylene-styrene (SEBS), and
wherein the laser absorber represents 20-90 wt. % of the at least one microsphere.
22. The composition according to claim 21 , wherein the compatibilizer is a functionalized polymer that is the copolymer of ethylene and glycidyl methacrylate (ethylene-GMA).
23. The laser-markable and laser-weldable composition according to claim 21 , wherein said composition contains 0.1-1.0 wt. %, based on the total composition of the microsphere.
24. The laser-markable and laser-weldable composition according to claim 21 , wherein the matrix polymer is one or more of polyethylene (PE), polypropylene (PP), polyamide (PA), polyester, polyether, polyphenylene ether, polyacrylate, polyurethane (PU), polyoxymethylene (POM), polymethacrylate, polymethylmethacrylate (PMMA), polyvinyl acetate (PVAC), polystyrene (PS), acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylate (ASA), ABS graft polymer, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polycarbonate (PC), polyether sulfones, polyether ketone, thermopolymer polyurethane (TPU), thermopolymer elastomers (TPE), epoxy resin (EP), silicon resin (SI), unsaturated polyester resin (UP), phenolic formaldehyde resin (PF), urea formaldehyde resin (UF), melamine resin (MF), ultrahigh-molecular polyethylene (UHMWPE), styrenics, styrolacrylnitril (SAN), thermoplastic vulcanizates, thermoplastic elastomers, silicone rubbers, or copolymers thereof and/or mixtures thereof.
25. A process for producing a laser-markable or laser-weldable composition according to claim 21 , said process comprising mixing said matrix polymer with the at least one microsphere and optionally with further additives, and shaping the composition with exposure to heat.