CN107043925B

CN107043925B - Molded article having functional layer, method for producing same, and use thereof

Info

Publication number: CN107043925B
Application number: CN201610816001.2A
Authority: CN
Inventors: 迈克尔·赛恩福鲁克; 马雷克·马勒卡; 罗伯特·马古尼亚; 佛罗莱恩·埃德尔; 妮娜·柏盖; 菲利克斯·诺图马斯
Original assignee: Lisa Draexlmaier GmbH
Current assignee: Lisa Draexlmaier GmbH
Priority date: 2015-09-09
Filing date: 2016-09-09
Publication date: 2021-08-27
Anticipated expiration: 2036-09-09
Also published as: DE102015115167A1; CN107043925A; DE102015115167B4

Abstract

The invention relates to a molded article, the surface of which is at least partially covered by a functional layer, to a method for producing the molded article, and to the use thereof; the invention further relates to a system, in particular a tool, comprising a moulding according to the invention, which has an increased stability against wear forces.

Description

Molded article having functional layer, method for producing same, and use thereof

Technical Field

The invention relates to a molded part whose surface is at least partially covered with a functional layer, to a method for producing said molded part, and to the use thereof; in particular the invention relates to a tool coated with a plasma polymer functional layer having a counteracting effect on the adhesion of adhesives such as so-called hot melt adhesives and dispersion adhesives. The invention further relates to a system, in particular a tool, with increased stability against frictional forces.

Background

Molded articles or target parts having plasma polymer functional layers are known in the art. A target part made of silver, which has a so-called plasma coating, is already described in german patent document DE 4216999 a 1.

Due to the gradual change of the process parameters, the coating has a layer structure comprising a coupling layer, a permeation barrier and a hard, scratch-resistant surface seal.

For producing the scratch-resistant layer, a mixture of oxygen and Hexamethyldisiloxane (HMDSO) is used.

Furthermore, a method for producing thin, strong hydrophobic polymeric layers by means of plasma polymerization is disclosed in german patent document DE 19543133 a 1. It is pointed out that vinylmethylsilane and vinyltrimethoxysilane as monomers are used for the plasma polymerization, they are monomers having at least one group which is low in affinity for oxygen, and they are capable of plasma polymerization with the structure being maintained as much as possible.

The monomer may be added with a gas incapable of polymerization, such as an inert gas, nitrogen gas or hydrogen gas, as an auxiliary gas or a carrier gas. Such an auxiliary or carrier gas is advantageous for improving the uniformity of the plasma and increasing the pressure in the gas phase.

A disadvantage of the coating disclosed in DE 19543133 is in particular that it is easily removable from the substrate as described above.

Furthermore, german patent document DE 19748240 a1 describes a method for the corrosion-resistant coating of a metal substrate by means of plasma polymerization, wherein the metal substrate is first mechanically, chemically and/or electrochemically polished in a first pretreatment step and plasma activated in a second process step before the plasma-polymerized coating is applied.

Hydrocarbon compounds and/or organosilicon compounds are disclosed as the main constituents of the plasma polymers, with particular preference being emphasized by the use of hexamethyldisiloxane and hexamethylcyclotrisiloxane.

Hexamethyldisiloxane is used in the examples in the above patent documents, in which oxygen or nitrogen can be mixed as an additional or auxiliary gas.

Detailed information such as the ratio of monomer to oxygen cannot be inferred in the above document. Furthermore, this patent document does not disclose how to apply the plasma polymerized coating or on which substrate the plasma polymerized coating is applied in order to be able to obtain a surface which is particularly easy to clean.

Disclosure of Invention

The object of the present invention is to provide a molded part, in particular a tool, with a functional layer, i.e. with a functional coating, the coating of which has anti-adhesive properties, in particular with respect to adhesives, for example with respect to so-called hot-melt adhesives or dispersion adhesives, and also corrosion-resistant properties, so that the downtime for cleaning (removal of adhering residues) or for replacement of damaged or worn tools in industrial production can be minimized, as well as a method for producing such a molded part with a functional coating.

The object is solved by a molded part which can be produced by the following method:

i. introducing and positioning the substrate or the molded part in an ADP (atmospheric pressure plasma) system, an NP (low pressure plasma) system or in a PACVD (plasma activated chemical vapor deposition) system;

treating the coated molded article under plasma conditions of each selected plasma such that a non-adherent coating having abrasion resistance is formed at least on at least a portion of the surface of the substrate/molded article.

In recent years, plasma technology has been established in almost all technical fields. Accordingly, a wide range of prior art is known in part for various embodiments. In addition to the fine purification and activation of the surface, in particular for the adjustment of the surface properties, plasma technology is also suitable for the coating of surfaces, for example for the coating of hydrophilic or hydrophobic layers, friction-reducing layers or barrier layers. The latter use is particularly important for solving the above-mentioned objects of the invention, with regard to the coating of components or workpieces of different kinds (substrates).

The plasma-assisted coating process according to the invention can be carried out in particular on the basis of three different process variants, including the low-pressure process (low-pressure plasma NP), the atmospheric-pressure process (atmospheric-pressure plasma ADP) and the so-called PACVD (plasma-activated chemical vapor deposition) process.

In the case of the low-pressure method, the gas is excited in a vacuum by an energy supply, for example by UV radiation. Thereby, in addition to electrons or other reactive particles, energetic ions forming a plasma are generated. This glow discharge type of low pressure plasma is used for coating. Here, a dispersed gas discharge (dispersion Gasendlaugen) in the range from 50 to 1000mm (Ausdehnnung) is generated in a pressure range from 1 to 100 Pa. Arc discharge is applied in a wide pressure range from low pressure to normal pressure, and is generally suitable for producing localized plasmas in the range of a few millimeters (ausdehnnung). Through these hot zones, either the gas to be treated is circulated for the conversion of the gas or energy is transported from the arc to the treatment zone by means of working gas jets (see variants at atmospheric pressure). When the reactive gas is supplied, the reactive gas decomposes in the discharge region and layer deposition occurs on the surface in the ambient environment, which may belong to the workpiece. The ionized gas chemically reacts with the surface of the substrate. Thus, the surface can be effectively conditioned or coated.

In the case of atmospheric variants, the gas is excited by means of a high pressure at ambient pressure, so that the plasma is ignited. The plasma is discharged from the nozzle under the application of compressed air.

By varying process parameters, such as the process rate and the distance from the substrate surface, as in the case of low-pressure processes, the process results may be influenced in different directions.

In the case of generating plasma in the atmospheric pressure range, barrier discharge or corona discharge is mainly used, which allows non-thermal energy distribution to be generated despite high collision frequency between electrons and heavy particles. In the case of barrier discharges, energy is introduced during a short time window of about 5-50ns by the automatic stopping of the discharge, while the corona discharge generates a very inhomogeneous electric field by means of a tip electrode (spitzer Elektroden) or a tank electrode (kantiger Elektroden). In both cases, the electrodes are energized only briefly, so that only a small number of collisions can occur.

Plasma-enhanced chemical vapor deposition-PACVD (PECVD) is a special form of Chemical Vapor Deposition (CVD), in which case chemical deposition is supported by a plasma. The plasma can be ignited directly at the substrate to be coated (direct plasma process) or in a separate chamber (remote plasma process). In CVD, molecules of the reaction gas are decomposed (spalled) by externally applied heat and a subsequent energy release of the chemical reaction takes place, whereas in PECVD, this task is taken up by accelerated electrons in the plasma. In addition to the radicals formed in this way, ions are also generated in the plasma, which together with the radicals cause the deposition of a layer on the substrate. The gas temperature in the plasma therefore generally rises only by a few hundred degrees celsius, so that it is also possible to coat heat-sensitive materials compared to CVD.

In the case of the direct plasma method, a strong electric field is established between the substrate to be coated and the counter electrode, by means of which field the plasma is ignited. In the case of the remote plasma method, the plasma is arranged without direct contact with the substrate. The advantage of selective stimulation of the individual components of the process gas mixture is thereby achieved and the probability of plasma damage to the substrate surface is reduced by the ions. It is also possible to inductively/capacitively generate plasma by transforming the radiation of an electromagnetic field

Within the framework of the invention, low-pressure plasmas or atmospheric plasmas are used in the given embodiment variants, atmospheric plasmas being preferred. Such a plasma may be present AS a commercially available device for plasma treatment, for example the plasma processor device AS 400(Plasmatreater AS 400) of the manufacturer pusima plasma treatment limited (statnarhagen GmbH, steinhagen (de)) of staunto, germany.

In the case of plasma polymerization, under the current control conditions, gaseous organic precursor compounds (precursor monomers) in the process chamber are first activated by the plasma. The ionized molecules produced by the activation have formed the first molecular fragments in the form of clusters or chains in the gas phase. Subsequent condensation of these fragments on the substrate surface leads to polymerization under the influence of substrate temperature, electron impact and ion impact and ultimately to the formation of a sealing layer.

It has surprisingly been found that, preferably in the case of the use of hydrocarbons and/or siloxanes as precursors, by means of plasma treatment of the moldings, it is possible to obtain coatings on the moldings used which have the desired adhesive counteraction with respect to adhesives, in particular hot-melt adhesives and dispersion adhesives, and which help the coated workpieces to obtain an increased protection against abrasive forces.

In this case, preferred among the above-mentioned hydrocarbon precursors are short-chain (1 to 10 carbon atoms) saturated or unsaturated hydrocarbons, among which methane, ethane and acetylene (acetylene) are particularly preferred.

Furthermore, preferred among the hydrocarbons are halogenated hydrocarbons, in particular saturated or unsaturated, cyclic fluorinated hydrocarbons, such as hexafluoroethane. Furthermore, octafluorocyclobutane and perfluorocyclopentene are particularly preferable as the cyclic hydrocarbon.

In the case of siloxane, poly (dimethylsiloxane) is preferred, including cyclosiloxanes such as hexamethylcyclotrisiloxane. Hexamethyldisiloxane is particularly preferred in the case of poly (dimethylsiloxane).

Mixtures of the above precursors can also be used.

Depending on the precursors used, it may be advantageous to heat the substrate, i.e. the molding or the tool, during coating.

The use of gases as process gases or ionized gases is likewise known from the prior art. They include gases such as argon, oxygen and/or nitrogen or inert gases, or gas mixtures such as air or compressed air, or nitrogen-hydrogen mixtures (gas mixtures of 95% nitrogen and 5% hydrogen).

Gas molecules are ionized in a (vacuum) processing apparatus, wherein a plasma is obtained by means of an electric field. The plasma for treating the composite material is preferably obtained by means of microwave radiation and a high-frequency alternating voltage, while pulsed direct-current plasma is preferably used in the plasma coating of substrates made of metal.

Detailed Description

The following exemplary plasma parameters give the plasma states for carbon-based and siloxane-based coatings, respectively:

A) parameters of the equipment

Free jet nozzle made of tungsten and copper, d-4 mm

Pulsed AC arc discharge (alternating current arc discharge) with target channel:

effective power 300W (effective voltage 1kV, effective current 0.3A)

2 pulses per period, 3.8kV peak value and 1.4 mu s pulse width

Tolerance is approximately +/-25% (achievable using a plasma processor AS 400 device)

Plasma voltage: 280V

Plasma frequency: 21kHz

Plasma cycle time: 10 to 20 percent

B) For an exemplary layer formulation of the organic carbon-based layer:

ionized gas: nitrogen (15001/h)

Precursor: acetylene (. about.381/h), 1-point-feed (1-Punkt-Einstemisung)

Nozzle outlet-substrate distance: 5-10mm

Track pitch of the planar (meandering) coating: 1-4mm (thickness of each layer)

Air injection speed: 5-10m/min (thickness of each layer)

Optionally: for example, annealing at 200 ℃ for 1.5h to improve adhesion/rapid case hardening (Soforteinatz).

C) For an exemplary layer formulation of the silicone base layer:

ionized gas: compressed air (-15001/h)

Precursor: hexamethyldisiloxane (. about.30 g/h), 1-point-feed

Nozzle outlet-substrate distance: 5-10 mm;

track pitch of the planar (meandering) coating: 1-4mm (thickness of each layer)

Air injection speed: 20-80m/min (thickness of each layer)

Optionally: for example, annealing at 200 c for 1.5h to improve adhesion/rapid case hardening.

Claims

1. A molded article having a non-stick coating against abrasion of a hot melt adhesive and/or a dispersion adhesive, which molded article can be produced by:

treating uncoated mouldings with a plasma in the presence of a process gas and an ionized gas in the presence of an organic precursor or an organosilicon precursor in a plasma treatment apparatus having a tungsten-copper free jet nozzle, in which apparatus: the tungsten-copper free jet nozzle has a diameter of 4mm and has a pulse alternating current arc discharge of a target channel with an effective power of 300W, wherein the effective voltage of the effective power is 1kV, and the effective current is 0.3A; and 2 pulses per cycle, with a peak voltage of 3.8kV and a pulse width of 1.4. mu.s, with a tolerance of +/-25%; the plasma voltage is 280V, the plasma frequency is 21KHz, the plasma cycle time is 10-20%,

wherein the organic precursor is selected from the group consisting of methane, ethane, and acetylene, the organosilicon precursor is polydimethylsiloxane, and the plasma is an atmospheric pressure plasma.

2. The molded article of claim 1, wherein the molded article is a tool.

3. The molded article of claim 2, wherein the tool is a capping device or a sewing knife.

4. The molded article according to claim 1, wherein the plasma is implemented as a coating with plasma-assisted chemical vapor deposition.

5. The molded article of claim 1, wherein the ionized gas is selected from the group consisting of oxygen, nitrogen, a gas mixture, and an inert gas.

6. The molded article of claim 5, wherein the gas mixture is selected from the group consisting of air, and a nitrogen-hydrogen mixture.

7. The molded article of claim 6, wherein the air is compressed air.

8. The molded article of claim 5, wherein the inert gas is argon.

9. The molding according to claim 5, characterized in that the ionized gas is nitrogen and is fed into the plasma chamber at a rate of-1500L/h and the precursor is acetylene, which is fed into the plasma chamber at a rate of-38L/h, wherein the distance from the nozzle outlet to the substrate is in the range of 5 to 10mm and is embodied as a planar, meandering coating having a layer thickness in the range of from 1 to 4mm with a gas jet speed in the range of 5 to 10 m/min.

10. The molding according to claim 1, characterized in that the ionized gas is compressed air and is fed into the plasma chamber at a rate of-1500L/h and the precursor is hexamethyldisiloxane, which is fed into the plasma chamber at a rate of-30 g/h, wherein the distance from the nozzle outlet to the substrate is in the range of 5 to 10mm and is implemented as a planar, meandering coating having a layer thickness in the range of from 1 to 4mm with a gas jet speed in the range of 20 to 80 m/min.

11. The molding according to claim 1, characterized in that in a further reaction step an annealing at 200 ℃ is carried out for 1.5 h.

12. A method for producing a molded article which is a non-stick coating according to one of claims 1 to 11 with an anti-abrasion against hot melt adhesives and/or dispersion adhesives, comprising the following process steps:

treating uncoated mouldings with a plasma in the presence of a process gas and an ionized gas in the presence of an organic precursor or an organosilicon precursor in a plasma treatment apparatus having a tungsten-copper free jet nozzle, in which apparatus: the diameter of the tungsten-copper free jet nozzle is-4 mm, and the tungsten-copper free jet nozzle is provided with a pulse alternating current arc discharge of a target channel with-300W effective power, wherein the effective voltage of the effective power is-1 kV, and the effective current is 0.3A; 2 pulses per cycle, with peak voltage 3.8kV and pulse width 1.4. mu.s, with a tolerance of +/-25%; the plasma voltage is 280V, the plasma frequency is 21KHz, the plasma cycle time is 10-20%,

wherein the organic precursor is selected from the group consisting of methane, ethane and acetylene, the organosilicon precursor is polydimethylsiloxane, and the plasma used in the method is atmospheric pressure plasma.

13. Method according to claim 12, characterized in that in the method the coating is carried out by means of plasma-assisted chemical vapor deposition.

14. The method according to any one of claims 12 to 13, wherein the ionized gas is selected from the group consisting of oxygen, nitrogen, a gas mixture and an inert gas.

15. The method of claim 14, wherein the gas mixture is selected from the group consisting of air, compressed air, and a nitrogen-hydrogen mixture.

16. The method of claim 15, wherein the air is compressed air.

17. The method of claim 14, wherein the inert gas is argon.

18. Method according to claim 12, characterized in that the ionized gas is nitrogen and is fed into the plasma chamber at a rate of-1500L/h and the precursor is acetylene, which is fed into the plasma chamber at a rate of-38L/h, wherein the distance from the nozzle outlet to the substrate is in the range of 5 to 10mm and is implemented as a planar, meandering coating with a layer thickness in the range of 1 to 4mm with a gas jet velocity in the range of 5 to 10 m/min.

19. The method according to claim 12, characterized in that the ionized gas is compressed air and is fed into the plasma chamber at a rate of-1500L/h and the precursor is hexamethyldisiloxane, which is fed into the plasma chamber at a rate of-30 g/h, wherein the distance from the nozzle outlet to the substrate is in the range of 5 to 10mm and is implemented as a planar, meandering coating with a layer thickness in the range of from 1 to 4mm with a gas jet velocity in the range of 20 to 80 m/min.

20. The method according to claim 12, characterized in that in a further reaction step the annealing is carried out at 200 ℃ for 1.5 h.

21. A system comprising a molded article according to one of claims 1 to 11.

22. The system of claim 21, wherein the system is embodied as a press lamination tool or a sewing machine.

23. Use of a molded article according to one of claims 1 to 11 as a means for pressure lamination or for producing a sewn connection.