JP2022546769A - Organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate - Google Patents

Abstract

The present disclosure is an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, comprising: (i) at least one organic solvent; (ii) metal flakes; and having a diameter ranging from 1 μm to 100 μm; (iii) at least one particulate metal having a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition; A composition comprising: one metal carbide; (iv) at least one binder;

Description

The present invention relates to organic solvent-based coating compositions for coating the surfaces of metal substrates to increase the coefficient of friction of the surfaces of the metal substrates; and methods of making such compositions. The invention is further directed to a method of coating a surface of a metal substrate; and to a metal substrate having a surface comprising such a coating.

The surfaces of metal substrates, especially ferrous metal substrates, are susceptible to corrosion, thereby degrading the material properties of such corroded metal surfaces.

Typically, an anti-corrosion coating is applied to the surface of a metal substrate to protect the metal surface from corrosion.

A typical such anti-corrosion coating may include a chromium coating. Such chromium coatings are rapidly passivated on contact with ambient air, thus providing an additional barrier layer to metal surfaces. However, the resulting products of such passivated chromium coatings can impair the decorative and/or functional properties of the surface of metal substrates.

Alternative anti-corrosion coatings may include aqueous and solvent-based anti-corrosion compositions containing particulate metals such as zinc and/or aluminum. Such zinc and/or aluminum coatings are typically electrochemically less noble than the surface of the metal substrate to which they are coated, thereby providing cathodic protection of the surface of the metal substrate. Such zinc and/or aluminum coatings can be applied directly to the surface of metal substrates to provide corrosion protection. However, due to the chemical reaction of such less noble zinc and/or aluminum coatings, the resulting products of such coatings can also impair the decorative and/or functional properties of the surface of the metal substrate. be.

However, the surfaces of many metal substrates commonly used in electronics and/or mechanical engineering are subject to mechanical stress during manufacturing, i.e., manufacturing tools exert mechanical forces on such surfaces. there is a possibility.

In addition to anti-corrosion properties, the surfaces of many metal substrates, such as metal screws, metal nuts, metal clamps, and/or metal springs, must withstand such mechanical forces. As a result, such metal surfaces typically include an increased coefficient of friction so that manufacturing tools can effectively exert mechanical forces on the metal surface without slipping off said surface. can.

GB 1380748 discloses a composition comprising a silane and a titanium compound as a binder which was a zinc-filled coating composition applied to a metal substrate.

GB-A-1499556 discloses a method of hydrolyzing ethylsilicate to provide a gellable hydrolyzate.

U.S. Pat. No. 4,209,555 discloses coatings for ferrous metals as cathodic protection which include thixotropes such as water, zinc powder, aluminum powder, sodium aluminum silicate, iron oxide, titanium dioxide ore, and clay. A coating is disclosed comprising:

GB 1212424 discloses a protective coating comprising a crosslinked polymer composition for cathodic protection of metal surfaces. These crosslinked polymer compositions are formed by the reaction of tetraalkyl titanate esters with polymers resulting from partial hydrolysis of tetraethylorthosilicate in aqueous acidic media.

EP-A-0808883 discloses a water-reducible, chromium-free coating composition for providing corrosion protection to metal substrates. The coating composition contains a high boiling organic liquid, particulate metal such as particulate zinc or aluminum, a thickening agent such as hydroxyethylcellulose, and a silane-based binder.

EP-A-1280863 discloses a chromium-free coating composition comprising aluminum and zinc particles as corrosion inhibitors and binders such as silicates and organic titanates.

U.S. Patent Application Publication No. 2007/0259172 discloses a coating composition for providing corrosion protection of metal substrates, the composition comprising metal particles and a film forming binder, the binder comprising titanate and poly A composition is disclosed that includes a functional polymer.

EP 1644451 describes a chromium-free anti-corrosion coating for metal parts, the composition comprising particulate metal and yttrium, zirconium, lanthanum, cerium, praseodymium, and at least one element selected from neodymium.

GB 1380748 British Patent Application No. 1499556 U.S. Pat. No. 4,209,555 GB 1212424 EP-A-0808883 European Patent Application Publication No. 1280863 U.S. Patent Application Publication No. 2007/0259172 EP 1644451

SUMMARY OF THE INVENTION Accordingly, in view of the prior art, an object of the present invention is to provide an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, Such compositions do not exhibit the above-mentioned drawbacks of known prior art coating compositions.

In particular, it is an object of the present invention to provide improved organic solvent-based coating compositions capable of providing coatings on a plurality of different types of metal substrates, especially ferrous metal substrates.

What is needed, therefore, is a method of depositing coatings that have good anti-corrosion properties, and most preferably even better mechanical properties, namely an increased coefficient of friction (correspondingly increased K value).

Another object of the present invention is to provide chromium-free organic solvent-based coating compositions that approach or even match the corrosion protection and/or mechanical properties of chromium coating compositions.

Furthermore, the object of the present invention is in particular an organic compound having effective anticorrosion protection to avoid undesired corrosion of coated metal surfaces and also having an increased coefficient of friction (correspondingly increased K value). To provide a solvent-based coating.

Yet another object of the present invention is to provide an organic solvent-based coating composition that provides good stability over the life of the composition.

Furthermore, it is an object of the present invention to provide an organic solvent-based coating composition that is also suitable for use for coating the surface of metal substrates.

Furthermore, it is an object of the present invention to provide an organic solvent-based coating composition, preferably with the cheapest possible chemicals, including a general coating composition that is as simple as possible.

These objects, and further objects not explicitly stated but which are readily derivable or identifiable from the context discussed by the introduction herein, are defined by claim 1 in accordance with the first aspect of the present invention. is achieved by an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, having all the features described in . Suitable modifications of the organic solvent-based coating composition of the invention are described in dependent claims 2-12.

Furthermore, claim 13 comprises a method for producing an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate according to the second aspect of the present invention.

According to a third aspect of the present invention, claim 14 comprises a method of coating a surface of a metal substrate.

According to a fourth aspect of the present invention, claim 15 comprises a metal substrate having a surface, the surface of the metal substrate comprising a coating obtainable by a coating method according to the third aspect.

The present invention is particularly useful in the field of coatings for electronics and/or mechanical engineering devices where protective coatings, such as corrosion protection, are required, and in particular increased coefficients of friction (correspondingly increased K values). , it is particularly suitable for depositing coatings on the surface of metal substrates. Typical metal substrates coated with coating compositions according to the present invention include metal screws, metal nuts, metal clamps, and/or metal springs. The basic material of the metal substrate may include iron, steel, known ferrous metals such as carbon steel, and mixtures thereof.

The present invention according to a first aspect thereof is an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, comprising:
(i) at least one organic solvent;
(ii) at least one particulate metal provided as metal flakes and having a diameter ranging from 1 μm to 100 μm;
(iii) at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition;
(iv) at least one binding agent;
A composition is provided comprising:

Accordingly, it is possible to provide an organic solvent-based coating composition for coating the surface of a metal substrate in order to increase the coefficient of friction of the surface of the metal substrate in an unpredictable manner, which is disclosed in the known prior art. does not exhibit the aforementioned drawbacks of the coating composition of .

In particular, the organic solvent-based coating composition according to the invention is suitable for depositing a coating on the surface of a metal substrate in order to increase the coefficient of friction (and correspondingly the K value) of the surface of the metal substrate, and Suitable for providing effective anti-corrosion protection of the surface of metal substrates.

In particular, organic solvent-based coating compositions are suitable for depositing coatings on a number of different types of metal substrates, such as iron or steel.

The present invention provides chromium-free, organic solvent-based coating compositions that at least approach the coating properties of chromium-based coating compositions.

The coatings achieved have good or even better anti-corrosion properties and have good or even better mechanical properties such as high coefficients of friction (correspondingly high K values).

Additionally, the present invention provides organic solvent-based coating compositions that provide good stability over the life of the composition.

Furthermore, the modified organic solvent-based coating composition of the present invention comprises a very simple general composition, mostly containing inexpensive chemicals.

The present invention according to a first aspect thereof is an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, comprising:
(i) at least one organic solvent;
(ii) at least one particulate metal provided as metal flakes and having a diameter ranging from 1 μm to 100 μm;
(iii) at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition;
(iv) at least one binding agent;
A composition is provided comprising:

Addition of at least one metal carbide in a total concentration ranging from 0.1 wt% to 5 wt%, along with other characteristics defined above, results in a good or even better (i.e. desirable) coefficient of friction of the coated surface (correspondingly K values) and good or even better corrosion protection, coating compositions are provided that allow coatings to be deposited on the surface of metal substrates.

In the context of the present invention, the terms "to increase the coefficient of friction" and "increased coefficient of friction" (or similar but corresponding language) are appropriate for the invention to achieve this effect. indicate that you must (iii) is preferably absent or present above or below the range of 0.1% to 5% by weight, respectively, and/or Or (ii) is the case with the difference that it is provided as metal flakes and not at least one particulate metal having a diameter in the range of 1 μm to 100 μm. As shown in the example below, when (ii) and (iii) are set as defined throughout this specification, preferably preferred, an increased coefficient of friction (corresponding K value) is obtained.

Metal carbides have a high melting point and are very hard and wear resistant, thus applying coating compositions with favorable mechanical properties such as increased friction coefficients (and correspondingly K values) to metal surfaces. enable

In the context of the present invention, the term "metal carbide" includes metal carbides, semi-metal carbides and transition metal carbides. Most preferred metal carbides are transition metal carbides.

By providing at least one binder in the composition, a coating of the surface of the metal substrate can be provided, which does not flake off the surface of the metal substrate. During the coating process, at least one binder secures the coating to the metal surface to be coated, and at least one binder is present in the coating composition for pigments (i.e., at least one particulate metal as well as at least one metal carbide and optionally further filler particles), thereby ensuring the formation of a permanent and stable coating.

Preferably, the at least one binder is adapted to provide a stable dispersion of the at least one particulate metal and the at least one metal carbide in the at least one organic solvent.

In the present invention, at least one particulate metal is provided as metal flakes.

Preferably, the at least one metal carbide is selected from the group consisting of transition metal carbides and semi-metal carbides,
Preferably, the at least one metal carbide is a metal of subgroups IV (“titanium group”) to VII (“manganese group”) of the periodic table of the elements;
preferably titanium carbide, tantalum carbide and/or tungsten carbide,
and/or metals of main group III (“boron group”) and/or main group IV (“carbon group”) of the periodic table of the elements,
preferably containing boron carbide and/or silicon carbide,
Most preferably, said at least one metal carbide is selected as tungsten carbide and/or silicon carbide.

The most preferred carbide in organic solvent-based coating compositions is tungsten carbide.

Preferred are organic solvent-based coating compositions of the invention in which at least one metal carbide is chemically unmodified. This preferably means that the surface of at least one metal carbide is not chemically modified. This further preferably means that the surface of at least one metal carbide is not chemically modified with amine and/or carboxyl sites.

Preferred are organic solvent-based coating compositions according to the invention, wherein at least one metal carbide has a diameter of less than 3 μm, preferably less than 2.5 μm.

Preferably, based on the total weight of the metal carbides, 50% or more of at least one metal carbide is less than 1 μm, preferably 900 nm or less, more preferably 800 nm or less, even more preferably 700 nm or less, even more preferably is an organic solvent-based coating composition of the present invention having a diameter of 600 nm or less, most preferably 500 nm or less.

Most preferably, at least 60% by weight of at least one metal carbide, based on the total weight of the metal carbide, is less than 1 μm, preferably 900 nm or less, more preferably 800 nm or less, even more preferably 700 nm or less, even more preferably Preferably, the organic solvent-based coating composition of the present invention has a diameter of 600 nm or less, most preferably 500 nm or less.

Preferably, the coating composition comprises at least one metal carbide in a total concentration ranging from 0.25 wt% to 3.5 wt%, preferably from 0.4 wt% to 2.4 wt%.

By selecting a preferred type of metal carbide and/or by selecting a preferred concentration range of at least one metal carbide, the coating on the surface of the metal substrate has an excellent coefficient of friction (correspondingly K value) and Includes corrosion protection.

Preferably, the at least one particulate metal comprises particulate aluminum and/or (preferably also) particulate zinc,
and/or at least one particulate metal comprises a metal-zinc-alloy, said metal comprising aluminum, magnesium, tin, nickel, cobalt and/or manganese;
Preferably, the at least one particulate metal is selected as particulate aluminum and/or (preferably also) particulate zinc.

Especially preferred are compositions according to the invention, wherein the at least one particulate metal comprises at least particulate zinc. More preferably, the at least one particulate metal comprises particulate zinc and particulate aluminum (preferably as separate particulate metals), and the organic solvent-based coating composition preferably comprises weight percent and organic solvent-based contains more particulate zinc than particulate aluminum, based on the total weight of the coating composition. In particular, zinc is required to achieve acceptable corrosion resistance.

The at least one particulate metal provided as metal flakes has a diameter ranging from 1 μm to 100 μm, preferably from 5 μm to 30 μm.

Preferred are organic solvent-based coating compositions of the invention in which the at least one particulate metal is not a powder. This most preferably means that particulate zinc and particulate aluminum are not present as powders in the organic solvent-based coating composition. In this context, "powder" usually refers to diameters well below 1 μm.

Various particulate metals, particularly zinc, in the coating composition provide increased cathodic protection of the coating composition. In particular, the combination of aluminum and zinc, preferably aluminum flakes and zinc flakes, as particulate metal ensures excellent properties of the coating. With at least one carbide as defined above, advantageously high coefficients of friction (and correspondingly K values) are obtained.

Preferably, the at least one particulate metal comprises particulate zinc in a concentration ranging from 31.5% to 49.5% by weight, based on the total weight of the coating composition.

Preferably, the at least one particulate metal comprises particulate aluminum in a concentration ranging from 2.6% to 9.8% by weight, based on the total weight of the coating composition.

Preferably, the at least one particulate metal comprises particulate aluminum and particulate zinc, preferably from 20% to 50%, preferably from 30% to 50% by weight, based on the total weight of the coating composition. Including the total concentration of the range.

By selecting the preferred concentration range of particulate zinc and/or particulate aluminum in the coating composition, the resulting coating on the surface of a metal substrate ensures excellent cathodic corrosion protection while avoiding metal carbides and In combination, excellent coefficients of friction (and correspondingly K values) are provided.

Preferably, particulate aluminum and particulate zinc are also provided as aluminum flakes and zinc flakes, respectively. Also, the aluminum flakes and zinc flakes preferably have a diameter ranging from 1 μm to 100 μm, more preferably from 5 μm to 30 μm.

Providing aluminum flakes and/or zinc flakes (preferably and preferably as described as preferred throughout the specification) allows efficient preparation of coating compositions according to the present invention, It contributes significantly to increasing the coefficient of friction (and correspondingly the K value).

The coating composition preferably comprises alcohols, including ethanol, isopropanol, butanol, butan-1-ol, and/or isooctanol; alkyl ethers of glycols, including preferably 1-methoxy-2-propanol; monoalkyl ethers of ethylene glycol. ketones, preferably including methyl ethyl ketone and/or methyl isobutyl ketone; isophorone; esters; ethers, preferably including 2-ethoxyethyl acetate and/or 2-ethoxyethanol; preferably benzene, toluene and/or xylene. aromatic hydrocarbons, preferably hydrotreated heavy naphtha oil and/or petroleum-derived aromatics, comprising mixtures of aliphatic and naphtha hydrocarbons containing less than 0.5% by weight of aromatics solvent blends; and mixtures thereof.

Preferably, the coating composition comprises at least one organic solvent in a total concentration ranging from 3% to 25%, preferably from 4% to 15% by weight, based on the total weight of the coating composition.

Preferred organic solvents and/or preferred concentration ranges of organic solvents allow efficient dispersion of all components of the coating compositions of the present invention.

Preferably, the coating composition preferably comprises ethers of hydroxyethylcellulose, methylcellulose, methylhydroxypropylcellulose, ethyl-hydroxyethylcellulose, methylethylcellulose, xanthan gum, urethane-based thickeners, organically modified clays, preferably organic organically modified hectorite and/or organically modified smectite clay; at least one thickening agent selected from the group consisting of fumed silica, hydrophilic fumed silica, modified urea and mixtures thereof; include.

However, in some cases silica-free organic solvent-based coating compositions are preferred.

Preferably, the coating composition comprises at least one wetting agent, preferably the wetting agent as a nonionic agent, more preferably as a nonionic alkylphenol polyethoxy adduct and/or alkoxylated polyalkylene, and/or preferably as an anionic wetting agent, more preferably as an organic phosphate and/or diester sulfosuccinate, even more preferably as sodium bistridecyl sulfosuccinate, and/or more preferably low-molecular-weight polymethylalkyl As siloxanes, most preferably polydimethylsiloxanes, and modifications thereof, even more preferably methylalkylpolysiloxanes, polyether siloxanes and/or polyester siloxanes are selected.

Preferably, the coating composition contains at least one A thickener and/or (preferably also) at least one humectant.

By selecting the thickener, preferably at a preferred concentration, the viscosity of the coating composition can be effectively adjusted. By selecting the wetting agent, preferably at a preferred concentration, the surface of the particulate metal and/or metal carbide can be effectively wetted.

Preferably, at least one binder is
- preferably 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(3-(trimethoxysilyl)propyl)ethylenediamine, N-(3-(triethoxysilyl)propyl)-ethylenediamine, vinyl tri selected from the group consisting of methoxysilane, vinyltriethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, (3-glycidyloxy-propyl)-triethoxysilane, and mixtures, oligomers and/or hydrolysates thereof silane agent,
and/or - monomers of silicate esters, preferably selected from the group consisting of tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, and mixtures, oligomers and/or hydrolysates thereof; / or at least one of the oligomers.

Preferably, the at least one silane agent has a total concentration ranging from 1 wt% to 50 wt%, preferably from 2 wt% to 35 wt%, based on the total weight of the coating composition.

Optionally and preferably the at least one binder has a total concentration ranging from 1% to 50%, preferably from 2% to 35% by weight, based on the total weight of the coating composition.

Preferably, the at least one binder comprises at least one titanate compound, preferably comprising titanium alkoxides and/or titanium chelates and/or titanate oligomers formed by partial hydrolysis of titanate monomers (preferably further includes),
Preferably, the titanium alkoxide comprises tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-tert-butyl titanate, and/or tetra-2-ethylhexyl titanate,
Preferably, the titanium chelate is a complex of titanium with at least one dicarbonyl compound, more preferably titanium diisopropoxide bis-(acetylacetonate), titanium oxyacetylacetonate, titanium diisopropoxide bis-(2 , 2,6,6-tetramethyl-3,5-heptanedionate), titanium bis-(ethyl-acetoacetato)-diisopropoxide, titanium 2-ethyl-1,3-hexanediolate, di-i-butoxy - bisethylacetoacetatotitanate and/or a complex of titanium with at least one (poly)hydroxyl carboxylic acid, even more preferably titanium bis-(ammonium-lactato)-dihydroxide and/or titanium and at least one comprising a chelate complex of the molecule with citric acid and/or a chelate complex of titanium with a polycarboxylic acid, even more preferably with oxalic acid,
Preferably, the titanate oligomer comprises polypropyltitanate and/or polybutyltitanate.

Preferably, the at least one titanate compound has a total concentration ranging from 1 wt% to 50 wt%, preferably from 10 wt% to 45 wt%, based on the total weight of the coating composition.

Preferably, the at least one binder is selected as at least one silane agent and at least one titanate compound (i.e. a mixture of both), preferably the total concentration of at least one silane agent and at least one titanate compound is , in the range of 1% to 50% by weight, preferably 20% to 45% by weight, based on the total weight of the coating composition.

The silane binder and/or (preferably also) the titanate binder, preferably in the preferred concentration range, make it possible to provide a coating on the surface of the metal substrate that does not flake off from the surface of the metal substrate.

Highly preferred are organic solvent-based coating compositions according to the invention, wherein the at least one binder comprises at least one titanate binder. Titanate binders are very beneficial for achieving good corrosion resistance.

Preferably, the organic solvent is free of water or the amount of water in the organic solvent is 1 wt% or less, preferably 0.1 wt% or less. Most preferably, the organic solvent-based coating composition of the present invention is free of water or the amount of water in the organic solvent is 1 wt% or less, preferably 0.1 wt% or less.

The use of organic solvents in (essentially) water-free coating compositions can enhance the coating effectiveness of the surface of metal substrates when using such coating compositions.

Preference is given to organic solvent-based coating compositions according to the invention which are substantially free, preferably free of lubricants. This ensures an increase in the coefficient of friction (and correspondingly the K value). More preferably, it is substantially free or preferably free of polypropylene wax, preferably substantially free or preferably free of polyalkylene wax, and most preferably substantially free of or preferably any wax. is an organic solvent-based coating composition according to the present invention, which does not contain Lubricants and waxes typically reduce the coefficient of friction, which is undesirable in the context of the present invention.

According to a second aspect, the present invention is directed to a method of making an organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, the method comprising:
(a) providing at least one organic solvent and at least one binder;
(b) providing at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition;
(c) providing at least one particulate metal provided as metal flakes and having a diameter in the range of 1 μm to 100 μm,
The compounds according to steps (a), (b) and/or (preferably also) (c) are provided together and/or (preferably or) individually and steps (a), (b), and/or (preferably also) the compounds according to (c) are preferably provided in different orders;
(d) mixing the compounds provided during steps (a) to (c) to obtain said organic solvent-based coating composition;
including.

By mixing the compounds of the compound mixture, a homogeneous (ie preferably having a homogeneous distribution) organic solvent-based coating composition can be obtained. Typically, the liquid compound is first provided before the solid compound is dispersed within the liquid compound. Some of the compounds according to steps (a) to (c) may be provided separately, depending on the specific properties and/or solubility of the various compounds. Alternatively, it is possible to provide some or all of the compounds according to steps (a) to (c) together.

Depending on the specific properties and/or solubilities of the various compounds, the order in which the compounds are provided may vary with respect to the specific compounds used.

Preferably, as a first step (a), at least one organic solvent is provided together with at least one binder and optionally additional liquid components, such as liquid additives, and as a second step (b), At least one metal carbide is provided along with any additional solid additives, as a third step (c) at least one particulate metal is provided, and as a fourth step (d) an organic solvent-based The compounds provided during steps (a) to (c) are mixed to obtain a coating composition of

Preferably, the mixture is stirred during steps (a), (b) and/or (c) for a defined time, preferably the defined time is more for liquid components than for solid compounds. is longer. The time preferably ranges from 1 minute to 60 minutes.

By adjusting the stirring time with respect to providing liquid or solid ingredients, efficient dispersion of the provided ingredients can be achieved.

Preferably, after step (d), the organic solvent-based coating composition is filtered, preferably through a sieve.

Filtration of the organic solvent-based coating composition after mixing can reduce agglomeration of the compounds, thereby ensuring a homogenous organic solvent-based coating composition.

The above (preferably stated as preferred) regarding the organic solvent-based coating composition according to the invention preferably likewise applies to the method of the invention for preparing the organic solvent-based coating composition. be.

Where applicable, the following preferred features preferably apply equally to organic solvent-based coating compositions according to the present invention.

Preferably for the method, the at least one metal carbide is selected from the group of transition metal carbides and/or metalloid carbides, more preferably the at least one metal carbide is selected from subgroup IV of the Periodic Table of the Elements (" titanium group") to VII ("manganese group"), even more preferably titanium carbide, tantalum carbide and/or tungsten carbide and/or main group III of the periodic table of the elements ("boron group") and/or metal ions of main group IV (“carbon group”), even more preferably boron carbide and/or silicon carbide, most preferably at least one metal carbide as tungsten carbide and/or silicon carbide to be chosen.

Preferred for the method is that the coating composition contains at least one metal carbide in a total concentration ranging from 0.25 wt% to 3.5 wt%, preferably from 0.4 wt% to 2.4 wt%. to include.

Preferably for the method at least one particulate metal is selected as particulate aluminum and particulate zinc and/or at least one particulate metal is selected as metal-zinc-alloy, the metal being aluminum , magnesium, tin, nickel, cobalt and/or manganese, preferably at least one particulate metal is selected as particulate aluminum and particulate zinc.

In the method, the at least one particulate metal is provided as metal flakes, having a diameter in the range 1 μm to 100 μm, preferably 5 μm to 30 μm.

Preferred for the method is that the at least one particulate metal comprises particulate zinc at a concentration ranging from 31.5% to 49.5% by weight, based on the total weight of the coating composition. .

Preferred for the method is that the at least one particulate metal comprises particulate aluminum in a concentration ranging from 2.6% to 9.8% by weight, based on the total weight of the coating composition. .

Preferably for the process the at least one particulate metal comprises particulate aluminum and particulate zinc, preferably from 20% to 50% by weight, preferably from 30% by weight, based on the total weight of the coating composition. Including at a total concentration in the range of 50% by weight.

Preferably for the process the particulate aluminum and/or particulate zinc is provided as aluminum flakes and/or zinc flakes, preferably the aluminum flakes and/or zinc flakes are between 1 μm and 100 μm, more preferably between 5 μm and 20 μm is to have a diameter in the range of

Preferred for the present method is that the coating composition preferably contains alcohols, including ethanol, isopropanol, butanol, butan-1-ol, and/or isooctanol; alkyl ethers of glycols, preferably including 1-methoxy-2-propanol. ethylene glycol monoalkyl ethers; diethylene glycol; propylene glycol; ketones, preferably methyl ethyl ketone and/or methyl isobutyl ketone; isophorone; esters or ethers, preferably 2-ethoxyethyl acetate and/or 2-ethoxyethanol; , preferably benzene, toluene and/or xylene; petroleum-derived aromatic solvent blends, preferably hydrotreated heavy naphtha oils and/or aliphatic and naphthas with an aromatics content of less than 0.5% by weight. At least one organic solvent selected as a mixture of hydrocarbons and mixtures thereof.

Preferred for the method is that the coating composition contains at least one organic solvent in a total concentration ranging from 3% to 25%, preferably from 4% to 15% by weight, based on the total weight of the coating composition. is to include in

Preferred for the present method, the coating composition comprises at least one thickening agent, preferably the thickening agent is ether of hydroxyethylcellulose, methylcellulose, methylhydroxypropylcellulose, ethyl-hydroxyethylcellulose, methylethylcellulose, xanthan gum, Urethane-based thickeners, organically modified clays, more preferably organically modified hectorite and/or organically modified smectite clays, fumed silica, hydrophilic fumed silica, modified urea and mixtures thereof.

Preferred for this method is that the coating composition comprises at least one wetting agent, preferably the wetting agent is a nonionic agent, more preferably a nonionic alkylphenol polyethoxy adduct and/or an alkoxylated poly as an alkylene and/or preferably as an anionic wetting agent, more preferably as an organic phosphate and/or diester sulfosuccinate, even more preferably as sodium bistridecyl sulfosuccinate, and/or more preferably as a low molecular weight As polymethylalkylsiloxanes, most preferably polydimethylsiloxanes, and modifications thereof, even more preferably methylalkylpolysiloxanes, polyether siloxanes and/or polyester siloxanes are selected.

Preferred for the present method is that the coating composition is , at least one thickener and/or at least one humectant.

Preferred for the process is that at least one binder is preferably 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(3-(trimethoxysilyl)propyl)ethylenediamine, N-(3 -(triethoxysilyl)propyl)-ethylenediamine, vinyltrimethoxysilane, vinyltriethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, (3-glycidyloxy-propyl)-triethoxysilane, silicate monomers and/or as at least one silane agent selected as an oligomer, more preferably tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, and mixtures, oligomers and/or hydrolysates thereof to be chosen.

Preferred for the method is that the at least one binder comprises at least one binder in a total concentration ranging from 1% to 50%, preferably from 2% to 35% by weight, based on the total weight of the coating composition. be selected as the silane agent.

Preferred for the process is at least one titanate, wherein the at least one binder is preferably selected as a titanium alkoxide and/or a titanium chelate and/or a titanate oligomer formed by partial hydrolysis of the titanate monomer. Titanium alkoxide selected as the compound, more preferably comprising tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-tert-butyl titanate, and/or tetra-2-ethylhexyl titanate , more preferably titanium chelates are complexes of titanium with at least one dicarbonyl compound, even more preferably titanium diisopropoxide bis-(acetylacetonate), titanium oxyacetylacetonate, titanium diisopropoxide bis -(2,2,6,6-tetramethyl-3,5-heptanedionate), titanium bis-(ethyl-acetoacetato)-diisopropoxide, titanium 2-ethyl-1,3-hexanediolate, di- i-butoxy-bisethylacetoacetatotitanate and/or a complex of titanium with at least one (poly)hydroxycarboxylic acid, even more preferably titanium bis-(ammonium-lactato)-dihydroxide and/or titanium with at least one molecule of citric acid and/or titanium with a polycarboxylic acid, even more preferably with oxalic acid, more preferably the titanate oligomer comprises polypropyltitanate and/or poly It is butyl titanate.

Preferably for the present method, the at least one binder comprises at least one binder in a total concentration ranging from 1 wt% to 50 wt%, even more preferably from 10 wt% to 45 wt%, based on the total weight of the coating composition. It is to be selected as one titanate compound.

Preferably for the method, the at least one binder is selected as the at least one silane agent and the at least one titanate compound, and the total concentration of the at least one silane agent and the at least one titanate compound is the total concentration of the coating composition. Based on weight, it should range from 1% to 50% by weight, preferably from 20% to 45% by weight.

Preferred for the process is that the organic solvent is free of water or the amount of water in the organic solvent is less than 1% by weight, preferably less than 0.1% by weight.

According to a third aspect, the present invention is directed to a method of coating a surface of a metal substrate, the method comprising:
(A) providing the metal substrate;
(B) providing an organic solvent-based coating composition for coating the surface of a metal substrate, the composition comprising:
(i) at least one organic solvent;
(ii) at least one particulate metal provided as metal flakes and having a diameter ranging from 1 μm to 100 μm;
(iii) at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition;
(iv) at least one binding agent;
a step comprising
(C) contacting a metal substrate with the organic solvent-based coating composition to deposit a coating on at least one side of the metal substrate; and (D) a metal substrate and a coating deposited on at least one side of the metal substrate. heating the coated coating to obtain a surface of said metal substrate with an increased coefficient of friction;
including.

What has been said above (preferably stated as being preferred) with respect to organic solvent-based coating compositions preferably likewise applies to the coating method according to the invention.

Preferred is the method according to the third aspect, wherein the coating has a thickness in the range 4 to 20 μm, preferably 6 to 10 μm.

Preferably, the coating is at least 0.28, preferably at least 0.29, more preferably at least 0.30, even more preferably at least 0.31, even more preferably at least 0.32, most preferably at least 0.33. A method according to a third aspect, which provides K values equal to or greater than

Preferably, the coating is at least 0.22, preferably at least 0.23, more preferably at least 0.24, even more preferably at least 0.25, even more preferably at least 0.26, most preferably at least 0.27 A method according to a third aspect, which provides the above coefficient of friction.

Optionally preferred is the method according to the third aspect, wherein at least steps (B), (C) and (D) are repeated, preferably at least twice. This is preferred if a thicker coating is desired after steps (B), (C) and (D) are used the first time. This can preferably be achieved if the method is carried out a second time with a substrate that already has a coating as a result of carrying out the method the first time.

Preferably for the method according to the third aspect, prior to step (B), the metal substrate, preferably by sandblasting the surface of the metal substrate or by phosphating the surface of the metal substrate, pre- to process.

By performing the pretreatment step, the surface of the metal substrate can be efficiently modified to improve the contact between the surface of the metal substrate and the coating.

Preferably for the method according to the third aspect, after step (C), the metal substrate is rotated to remove excess coating composition from the metal substrate.

Preferred for the method according to the third aspect is to heat the metal substrate to a temperature in the range 150°C to 350°C, preferably 200°C to 300°C during step (D).

Preferably for the method according to the third aspect, during step (C) the organic solvent-based coating composition is sprayed onto the surface of the metal substrate during the spraying step and/or during step (C) The metal substrate is immersed in the organic solvent-based coating composition during the immersion process.

Preferred for the method according to the third aspect, the metal substrate comprises metal screws, metal nuts, metal clamps and/or metal springs.

Preferred for the method according to the third aspect is that the coated surface of the metal substrate obtained after step (D) comprises a K value of 0.3 to 0.5. Preferably, the value measured for evaluating the coefficient of friction of the coated surface of the metal substrate according to the invention is the K value (i.e. the K value is an indication for the coefficient of friction, although both values are not identical). not), which is determined by the following formula K=T/F×d according to item 10.1 of standard DIN EN ISO 16047, where T corresponds to the tightening torque (“Anziehdrehmoment”) and F corresponds to the preload force (“Vorspannkraft”) and d to the nominal thread diameter (“Gewindenenndurchmesser”). See the Examples section of this application for further details.

Preferred for the method according to the third aspect, the metal of the metal substrate is a ferrous metal, preferably iron or steel.

Preferred is the method according to the third aspect, wherein no current is applied in step (C).

According to a fourth aspect, the invention is directed to a metal substrate having a surface, the surface of the metal substrate comprising a coating obtained by the coating method according to the third aspect.

What has been said above (preferably stated as preferred) regarding the method according to the third aspect according to the invention preferably likewise applies to the metal substrate of the invention.

Preferably for the substrate, the metal substrate comprises metal screws, metal nuts, metal clamps and/or metal springs.

Preferred for this substrate is that the coated surface of the metal substrate comprises a K value of 0.3 to 0.5. See the Examples section of this application for further details regarding K values.

Preferred for the substrate is that the metal of the metal substrate is a ferrous metal, preferably iron or steel.

The following non-limiting examples are provided to illustrate embodiments of the invention and to facilitate the understanding of the invention, but not limiting the scope of the invention as defined by the claims appended hereto. It is not intended to be limiting.

[Organic solvent-based coating composition]
In general, all experiments, including experiments according to the invention and comparative embodiments other than the invention, used at least one additive containing particulate zinc, particulate aluminum, at least one additive, at least one titanate compound and at least one silane agent. It should be mentioned that this was done using an organic solvent-based coating composition comprising one binder and at least one organic solvent. Particulate zinc and particulate aluminum are provided as flakes having diameters ranging from at least 5 μm to 15 μm. This is generally a very preferred diameter for particulate metals utilized in the present invention.

In all experiments, at least one additive included hydrophilic fumed silica as a thickening agent and polymethylalkylsiloxane as a wetting agent.

In all experiments, at least one titanate was tetra-n-butyl titanate, polybutyl titanate, titanium bis-(ethyl-acetoacetato)-diisopropoxide, and tetra-2-ethylhexyl titanate, tetra-n-propyl titanate, Selected as tetraisopropyl titanate and tetra-tert-butyl titanate.

In all experiments, at least one silane was selected as (3-glycidyloxypropyl)trimethoxysilane, (3-glycidyloxypropyl)triethoxysilane, 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane. be done.

In all experiments, at least one organic solvent was hydrotreated heavy naphtha oil, isooctanol, butan-1-ol, and aliphatic and naphthenic solvents with an aromatics content of less than 0.5% by weight. is selected as a mixture of hydrocarbons of

In the organic solvent-based coating composition according to this experiment, at least one metal carbide is added, preferably tungsten carbide (D ₅₀ : 200 nm), abbreviated as WC, and/or silicon carbide, abbreviated as SiC.

To prepare the organic solvent-based coating composition, all ingredients are added to a container in a prescribed order and a dissolver is used during the pre-dispersion step to allow for breakup of agglomerated ingredients. Mix. In this experiment, at least one organic solvent was added during the first step, at least one additive was added during the second step, and particulate aluminum, particulate zinc, at least one A solid component containing one titanate compound and at least one silane is added.

The reaction mixture is stirred after each component is added. The mixture is then filtered through a sieve of defined mesh size to obtain an organic solvent-based coating composition. The composition parameters of the organic solvent-based coating composition are then determined, in particular viscosity, density, average particle size and/or solids content.

[Coating on the surface of the metal substrate]
Organic solvent-based coating compositions make it possible to coat the surface of a metal substrate in order to increase the coefficient of friction of the surface of the metal substrate. Metal substrates to be coated include metal screws, metal nuts, metal clamps and/or metal springs.

In a first coating step, the metal substrate, which is usually coated with lubricating oil, is preferably cleaned with an alkaline degreaser. In a second coating step, the cleaned metal substrate is pretreated, preferably by sandblasting the surface of the metal substrate.

In a third coating step, the pretreated metal substrate is dipped into a corresponding coating composition according to embodiments to apply the coating composition to the surface of the metal substrate. Preferably, the pretreated metal substrate is immersed at 10° C. to 35° C. for 30 seconds to 1 minute, after which the pretreated metal substrate is immersed at 15° C. to 28° C. for 30 seconds to 1 minute. Preferably, the pretreated metal substrate is transferred into the corresponding coating composition during dipping.

In a fourth coating step, the metal substrate is spun to remove excess coating composition from the metal substrate, leaving only a thin film of coating composition on the surface of the metal substrate.

In a fifth coating step, the metal substrate containing the film of the coating composition is heated for a predetermined time at a temperature in the range of 300° C., preferably at 230° C. for 30 minutes to remove volatile components from the coating composition and coating The remaining components of the composition are allowed to chemically react to form a coating on the surface of the metal substrate.

[Mechanical properties of the coated surface of the metal substrate]
To evaluate the mechanical properties of the various coatings applied to the surfaces of the various metal substrates according to this experiment, the friction coefficients of the coated surfaces of the various metal substrates are determined according to standard DIN EN ISO 16047. The coefficient of friction (CoF) and the K value are proportional to each other. During the experiments of the present invention, CoF as well as K values are measured and evaluated.

The coefficient of friction (CoF) of the coated surface of the metal substrate according to the invention is determined analogously to the K value, where the K value is the following formula according to item 10.1 of standard DIN EN ISO 16047: K=T /F×d, where T corresponds to the tightening torque (“Anziehdrehmoment”), F corresponds to the preload (“Vorspannkraft”) and d corresponds to the nominal thread diameter (“Gewindenenndurchmesser”) . CoF was also determined according to DIN EN ISO 16047.

To experimentally determine the K value, a metal substrate, in particular a metal screw and/or a metal nut, is placed on a test stand, where the test stand is adapted to apply a torque value to the metal substrate and the test stand is It is adapted to measure various experimental values such as various coefficients of friction. For detailed information on how to derive the K value from the various measured coefficients of friction, please refer to the mathematical relationships according to standard DIN EN ISO 16047.

[Experimental data]
All concentrations of the different coating compositions shown in Tables 1 and 2 are given in weight percent (wt%), based on the total weight of the coating composition, unless otherwise specified.

The experiments presented in Tables 1 and 2 are numbered in order of their results.

Turning now to the tables, Table 1 shows experiments performed on organic solvent-based coating compositions according to embodiments of the present invention, and Table 2 shows comparative experiments on organic solvent-based coating compositions.

Comparing Runs 1-5 with Comparative Runs 6 and 7, it can be seen that the addition of metal carbides, namely silicon carbide (see Example 1) and/or tungsten carbide (see Examples 2-5), improves the performance of the respective coating composition. It can be derived that the K value of the coated surface of the metal substrate obtained after the coating process is increased.

In particular, increasing the tungsten carbide content from 0.5 wt% (see Example 2) to 1.5 wt% (see Example 4) reduces the K value from 0.29 (see Example 2) This results in an increase to 0.32 (see Example 4). An optimum K value of 0.35 is obtained when using the composition according to Example 5 with an amount of tungsten carbide of 1.70% by weight.

at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition; and at least one particle provided as metal flakes and having a diameter ranging from 1 μm to 100 μm. Own experiments have shown that similar metals are very important for obtaining increased K values (correspondingly CoF). As indicated above, in the absence of said at least one metal carbide, the K value (and correspondingly CoF) is low and unsatisfactory. Similar undesired results are also obtained when, for example, as powder, particulate metal flakes with a significantly smaller diameter, for example significantly less than 1 μm, are used.

Claims (15)

An organic solvent-based coating composition for coating the surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, comprising:
(i) at least one organic solvent;
(ii) at least one particulate metal provided as metal flakes and having a diameter ranging from 1 μm to 100 μm;
(iii) at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition;
(iv) at least one binding agent;
A composition comprising: said at least one metal carbide is selected from the group consisting of transition metal carbides and semi-metal carbides;
Preferably, said at least one metal carbide is a metal of subgroups IV (“titanium group”) to VII (“manganese group”) of the periodic table of the elements;
preferably titanium carbide, tantalum carbide and/or tungsten carbide,
and/or metals of main group III (“boron group”) and/or main group IV (“carbon group”) of the periodic table of the elements,
preferably containing boron carbide and/or silicon carbide,
Organic solvent-based coating composition according to claim 1, wherein most preferably said at least one metal carbide is selected as tungsten carbide and/or silicon carbide. 2. The coating composition of claim 1, wherein said coating composition comprises said at least one metal carbide in a total concentration ranging from 0.25 wt% to 3.5 wt%, preferably from 0.4 wt% to 2.4 wt%. or an organic solvent-based coating composition according to 2. said at least one particulate metal comprises particulate aluminum and/or particulate zinc;
and/or said at least one particulate metal comprises a metal-zinc-alloy, said metal comprising aluminum, magnesium, tin, nickel, cobalt and/or manganese;
Organic solvent-based coating composition according to any one of the preceding claims, wherein preferably said at least one particulate metal is selected as particulate aluminum and/or particulate zinc. An organic solvent-based coating composition according to any one of the preceding claims, wherein said at least one particulate metal provided as metal flakes has a diameter ranging from 5 µm to 30 µm. 6. Any of claims 1-5, wherein the at least one particulate metal comprises particulate zinc in a concentration ranging from 31.5% to 49.5% by weight, based on the total weight of the coating composition. An organic solvent-based coating composition according to claim 1. 7. Any of claims 1-6, wherein the at least one particulate metal comprises particulate aluminum in a concentration ranging from 2.6% to 9.8% by weight, based on the total weight of the coating composition. An organic solvent-based coating composition according to claim 1. Said coating composition preferably comprises ethers of hydroxyethylcellulose, methylcellulose, methylhydroxypropylcellulose, ethyl-hydroxyethylcellulose, methylethylcellulose, xanthan gum, urethane-based thickeners, organically modified clays, preferably organically modified hectorite and/or organically modified smectite clay; at least one thickener selected from the group consisting of fumed silica, hydrophilic fumed silica, modified urea and mixtures thereof. An organic solvent-based coating composition according to any one of items 1-7. The at least one binder is
- preferably 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-(3-(trimethoxysilyl)propyl)ethylenediamine, N-(3-(triethoxysilyl)propyl)-ethylenediamine, vinyl tri selected from the group consisting of methoxysilane, vinyltriethoxysilane, (3-glycidyloxypropyl)trimethoxysilane, (3-glycidyloxy-propyl)-triethoxysilane, and mixtures, oligomers and/or hydrolysates thereof silane agent,
and/or - monomers of silicate esters, preferably selected from the group consisting of tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, and mixtures, oligomers and/or hydrolysates thereof; Organic solvent-based coating composition according to any one of the preceding claims, comprising at least one of/or oligomers. 10. The method of claim 9, wherein the at least one silane agent has a total concentration ranging from 1 wt% to 50 wt%, preferably from 2 wt% to 35 wt%, based on the total weight of the coating composition. Organic solvent-based coating composition. said at least one binder comprises at least one titanate compound, preferably comprising titanium alkoxides and/or titanium chelates and/or titanate oligomers formed by partial hydrolysis of titanate monomers;
Preferably, said titanium alkoxide comprises tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-tert-butyl titanate, and/or tetra-2-ethylhexyl titanate,
Preferably, said titanium chelate is a complex of titanium with at least one dicarbonyl compound, more preferably titanium diisopropoxide bis-(acetylacetonate), titanium oxyacetylacetonate, titanium diisopropoxide bis-( 2,2,6,6-tetramethyl-3,5-heptanedionate), titanium bis-(ethyl-acetoacetato)-diisopropoxide, titanium 2-ethyl-1,3-hexanediolate, di-i- butoxy-bisethylacetoacetatotitanate and/or a complex of titanium with at least one (poly)hydroxyl carboxylic acid, even more preferably titanium bis-(ammonium-lactato)-dihydroxide and/or titanium and at least containing one molecule of a chelate complex with citric acid and/or a chelate complex of titanium with a polycarboxylic acid, even more preferably with oxalic acid,
Organic solvent-based coating composition according to any one of the preceding claims, wherein preferably said titanate oligomers comprise polypropyltitanate and/or polybutyltitanate. 12. Organic according to claim 11, wherein said at least one titanate compound has a total concentration of 1 wt% to 50 wt%, more preferably 10 wt% to 45 wt%, based on the total weight of said coating composition. Solvent-based coating composition. A method of making an organic solvent-based coating composition for coating a surface of a metal substrate to increase the coefficient of friction of the surface of the metal substrate, comprising:
(a) providing at least one organic solvent and at least one binder;
(b) providing at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of said coating composition;
(c) providing at least one particulate metal provided as metal flakes and having a diameter in the range of 1 μm to 100 μm;
wherein the compounds according to steps (a), (b) and/or (c) are provided together and/or individually and said compounds according to steps (a), (b) and/or (c) are preferably provided in various orders,
(d) mixing said compounds provided during steps (a) to (c) to obtain said organic solvent-based coating composition;
A method, including A method of coating a surface of a metal substrate, comprising:
(A) providing the metal substrate;
(B) providing an organic solvent-based coating composition for coating the surface of a metal substrate, said composition comprising:
(i) at least one organic solvent;
(ii) at least one particulate metal provided as metal flakes and having a diameter ranging from 1 μm to 100 μm;
(iii) at least one metal carbide in a total concentration ranging from 0.1% to 5% by weight based on the total weight of the coating composition;
(iv) at least one binding agent;
a step comprising
(C) contacting the metal substrate with the organic solvent-based coating composition to deposit a coating on at least one side of the metal substrate; and (D) on the metal substrate and at least one side of the metal substrate. heating the deposited coating to obtain a surface of the metal substrate with an increased coefficient of friction;
A method, including A metal substrate having a surface, the surface of the metal substrate comprising a coating obtained by a coating method according to claim 14.