Process for producing metallized multi-layer bodies from special polycarbonates
View Patent ↗The invention relates to a process for producing multi-layer bodies which carry at least one metal layer. The invention further relates to multi-layer products having at least three layers, comprising a substrate layer made of a substrate and containing special copolycarbonates, a metal layer and at least one additional layer.
1. A process for producing a multilayer structure, comprising processing a substrate material comprising a copolycarbonate which comprises at least one bisphenol unit of formula (2)
in which
R2 comprises C1-C4-alkyl,
n is 0, 1, 2, or 3,
and comprises as terminal group, a structural unit of formula (1)
in which
R1 are hydrogen or C1-C18-alkyl,
and has a Vicat softening point in accordance with DIN ISO 306 above 160° C., to give a molding,
and pretreating said molding with an air- or argon-based plasma and then metalizing by a sputtering process in a DC magnetron,
wherein
(a) based on the total amount of the bisphenol blocks, from 15% by weight to 50% by weight of the substrate material is composed of a bisphenol unit derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and the plasma pretreatment uses medium-frequency excitation with an air- or argon-based plasma at a frequency of from 0 Hz to 10 Mhz at a power level of from 0.4 W/cm 2 to 8.4 W/cm 2 and a process gas pressure of from 0.04 to 0.4 mbar, or
(b) based on the total amount of the bisphenol blocks, from 51% by weight to 95% by weight of the substrate material is composed of a bisphenol unit derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and the plasma pretreatment uses medium-frequency excitation with an air- or argon-based plasma at a frequency of from 0 Hz to 10 Mhz at a power level of from 3.1 W/cm 2 to 8.3 W/cm 2 and a process gas pressure of from 0.04 to 0.15 mbar.
2. The process as claimed in claim 1 , wherein R2 is methyl, ethyl, propyl, isopropyl, and butyl, or isobutyl moiety, n is 2 or 3, provided that the structural unit of the formula (1) is a phenolate moiety or a tert-butylphenolate moiety, or an n-butylphenolate moiety, optionally a phenolate moiety or a p-tert-butylphenolate moiety.
3. The process as claimed in claim 1 , wherein, based on the weight of the copolycarbonate, the copolycarbonate comprises from 0.01% by weight to 0.10% by weight of triphenylphosphine, and also from 0.01 to 0.4% by weight of pentaerythritol tetrastearate.
4. The process as claimed in claim 1 , wherein, based on the weight of the copolycarbonate, the copolycarbonate comprises an amount of from 0.10% by weight to 2.50% by weight of titanium dioxide.
5. The process as claimed in claim 1 , further comprising producing a metalized molded part.
6. The process as claimed in claim 1 , wherein the multilayer structure also comprises, on a metal layer, a protective layer comprising one or more plasma-polymerized siloxanes.
7. The process as claimed in claim 6 , wherein the thickness of a substrate layer is from 0.1 mm to 6.0 mm, the thickness of the metal layer is from 10 nm to 1000 nm, and the thickness of the protective layer is from 5 nm to 200 nm.
8. The process as claimed in claim 6 , wherein the metal layer is an aluminum or silver layer.
9. The process as claimed in claim 6 , further comprising producing a reflector, or a lamp holder or lamp cover.
10. The process as claimed in claim 1 , wherein (a) is performed and said pretreating with plasma comprises using medium-frequency excitation with an air or argon-based plasma at a frequency of from 0 Hz to 1 Mhz at a power level of from 0.5 W/cm 2 to 5.0 W/cm 2 and a process gas pressure of from 0.05 to 0.2 mbar.
11. The process as claimed in claim 1 , wherein (a) is performed and said pretreating with plasma comprises using medium-frequency excitation with an air or argon-based plasma at a frequency of from 0 Hz to 100 kHz at a power level of from 0.8 W/cm 2 to 4.2 W/cm 2 and a process gas pressure of from 0.06 to 0.16 mbar.
12. The process as claimed in claim 1 , wherein (b) is performed and said pretreating with plasma comprises using medium-frequency excitation with an air or argon-based plasma at a frequency of from 0 Hz to 1 Mhz at a power level of from 3.2 W/cm 2 to 5.0 W/cm 2 and a process gas pressure of from 0.05 to 0.12 mbar.
13. The process as claimed in claim 1 , wherein (b) is performed and said pretreating with plasma comprises using medium-frequency excitation with an air or argon-based plasma at a frequency of from 0 Hz to 100 kHz at a power level of from 3.3 W/cm 2 to 4.2 W/cm 2 and a process gas pressure of from 0.05 to 0.12 mbar.
14. The process as claimed in claim 1 , wherein R2 is methyl, ethyl, propyl, isopropyl, and butyl, or isobutyl moiety, n is 2 or 3, and, if the structural unit of the formula (1) is a phenolate moiety or a p-tert-butylphenolate moiety.
15. The process as claimed in claim 1 , wherein based on the total amount of the bisphenol blocks, from 15% by weight to 50% by weight of the substrate material is composed of a bisphenol unit derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and the plasma pretreatment uses medium-frequency excitation with an air- or argon-based plasma at a frequency of from 0 Hz to 10 Mhz at a power level of from 0.4 W/cm 2 to 8.4 W/cm 2 and a process gas pressure of from 0.04 to 0.4 mbar.
16. The process as claimed in claim 1 , wherein based on the total amount of the bisphenol blocks, from 51% by weight to 95% by weight of the substrate material is composed of a bisphenol unit derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and the plasma pretreatment uses medium-frequency excitation with an air- or argon-based plasma at a frequency of from 0 Hz to 10 Mhz at a power level of from 3.1 W/cm 2 to 8.3 W/cm 2 and a process gas pressure of from 0.04 to 0.15 mbar.