This application claims the benefit of European Patent Application 20382700.1 filed on Jul. 30, 2020.
The present invention relates to the field of chemistry, more particularly to coating materials. In particular, the invention relates to modified static dissipative materials, particularly clays, functionalised with inorganic or organic moieties, and to a process for their preparation. It also relates to coating compositions comprising the modified static dissipative materials, particularly clays, which show omniphobic and antistatic properties, and to articles of manufacture coated with these compositions.
Surface contamination implies a huge negative effect on a broad range of applications, as it could lead to significant safety and health risks, detrimental impact on performance and high maintenance costs.
To solve this surface contamination problem, nowadays there are some solutions that are based in the substance to be repelled. For example, water and oil repellence is achieved by surface structuration and/or low surface energy materials, mainly fluorinated materials (F-materials) and silicones.
Another important problem that has been studied recently is the repellence of dust. To solve this problem, several approaches have been developed, such as: superhydrophobic coatings (water droplets are required to remove the solid particles from the surface), hydrophilic coatings, photocatalytic coatings, antistatic coatings (hydrophilic behaviour, conductive polymers, conductive particles), electrodynamic screens (active coatings). Laponite nanoparticles, a synthetic type of silicate nano-clay in the smectite family have also been used for inducing antistatic and dust-repellency effects thanks to their intrinsically ionic and electrical conductivity resulting from its configuration as a continuous layer.
Although there is a lot of work in the development of these types of solutions, there are only few approaches that overcome the repellence of both liquids and dust contamination.
The current solutions for simultaneously repelling liquids and dust particles related to antistatic effects are based on structured layers. This approach requires at least the fabrication of a conductive layer which is modified with a low surface energy material in a second step. These solutions involve several steps, with consequent time consuming and, furthermore, complex equipment are often required, leading to high production cost. On the other hand, superhydrophobic surfaces based solutions involve micro/nanostructured motifs which not only affect the material aesthetics, but also suffer from weak mechanical resistance since their damages result on the loss of the repellent capability of the material.
Fenero M. et al (ACS Applied Materials & Interfaces 2017) disclose transparent, antistatic, and omniphobic multifunctional laponite-based films prepared from a 7:3 mixture of unmodified laponites and modified laponites with a degree of functionalisation of 60%, which is equivalent to a global laponite functionalisation of about 18%. The modified laponites were obtained by adding a mono-silylated fluorinated compound (1H,1H,2H,2H-perfluorooctyltriethoxysilane) to a dispersion of Laponite XLG. As explained in the article, films processed from a 4% (w/v) ethanolic-aqueous gel only containing modified laponites (60% functionalisation) were not electrically conductive, which has a negative impact on the dust-repellent functionality. It is explained that the possible cause is the fact that the quantitative functionalisation of the laponite clays blocked the electrical charge transport and distorted the interlinked and overlapping arrangement of the laponite platelets.
Thus, taking into account the teachings in the prior art there is still a need of providing single formulations which are capable of providing liquid and dust repellence at a time while showing good mechanical resistance.
The present inventors have developed new modified static dissipative materials, particularly clays, in particular new modified laponites, which are highly functionalised with inorganic or organic moieties. When used as coating materials for a variety of substrates, the modified static dissipative materials, not only provide omniphobic characteristics, but also present antistatic properties. This finding was totally unexpected since, according to Fenero et al, the process of functionalisation alters this continuous layer, and laponites must be configured as a continuous layer in order to obtain ionic an electrical conductivity, and thus, antistatic and dust-repellency effects.
Additionally, as illustrated in the examples below, and unlike the multifunctional laponite-based films of the prior art, the modified static dissipative materials of the present invention, particularly clays, show good adhesion to the substrates to which they are applied. As a result, the static dissipative materials of the present invention show improved mechanical properties, in particular improved abrasion resistance. Without being bound to theory it is thought that the presence of at least two reactive functional groups in the inorganic or organic moieties used to modify the static dissipative materials, particularly clays, allows the simultaneous anchoring to both, the static dissipative materials, particularly the clay nanoparticles, and the substrate surface to which the coating is applied, thus improving the adhesion and consequent mechanical performance of the coatings.
Thus, in the present invention the ability to repel fouling agents (liquids and dust particles) by two different mechanisms (omniphobicity and antistatic) is achieved by using a single composition. A further advantage of the coatings of the invention is that their fabrication can be performed by using conventional techniques such as dip-coating, bar-coating, spin-coating and the like.
Therefore, a first aspect of the invention relates to a modified static dissipative material, comprising:
The modified static dissipative materials of the invention, particularly clays, may be used to prepare coating compositions with holistic self-cleaning properties against liquids, solids and liquid-solid mixtures. Thus, a second aspect of the invention relates to a coating composition comprising the modified static dissipative material as previously defined and one or more carriers or additives.
A third aspect of the invention relates to a process for the preparation of the modified static dissipative material, as previously defined, which comprises the following steps:
A fourth aspect of the invention relates to a process for coating at least part of the surface of a substrate which comprises applying the coating composition as previously defined to at least part of the surface of a substrate.
A fifth aspect of the invention relates to an article of manufacture coated with the coating composition as previously defined.
All terms as used herein in this application, unless otherwise stated, shall be understood in their ordinary meaning as known in the art. Other more specific definitions for certain terms as used in the present application are as set forth below and are intended to apply throughout the description and claims.
The term “about” or “around” as used herein refers to a range of values ±10% of a specified value. For example, the expression “about 10” or “around 10” includes ±10% of 10, i.e. from 9 to 11.
The term “clay” as used herein refers to a natural or synthetic clay and refers to particles of layered mineral silicates stacked together. They have intrinsic electrical conductivity. Clays are characterized by chemical composition and nanoparticle morphology. Clays of nanometric size are known as nano-clays and typically have dimensions ranging from 1-500 nm as measured by transmission electron microscopy (TEM). Depending on chemical composition and nanoparticle morphology, nanoclays are organized into several classes. Non-limiting examples of clays such as laponites, smectites, montmorillonites, bentonites, kaolinites, hectorites, and halloysites.
The terms “modified static dissipative material” or “functionalised static dissipative material”, and “modified clay” or “functionalised clay” as used herein refer to a static dissipative material or clay that has been chemically and/or structurally altered by chemically binding of molecules, in particular inorganic or organic compounds having two or more reactive functional groups, to its surface.
As used herein, the term “moiety” refers to a portion or fragment of a compound or molecule. Thus, “inorganic or organic moiety having two or more reactive functional groups” refers to the fragment of an inorganic or organic compound having two or more reactive functional groups, which is chemically attached to the static dissipative material.
The term “omniphobic” as used herein refers to a material which is simultaneously hydrophobic and oleophobic, i.e., a material which has the ability to repel liquids, in particular both water and oils.
The term “antistatic” as used herein refers to a material which is able to dissipate, or remove a static charge, i.e., a material which shows low adhesion to solid particles such as dust particles. Antistatic materials have thus the ability to repel solids.
The term “wettability” as used herein refers to the ability of a liquid to maintain contact with a solid surface, and it is controlled by the balance between intermolecular interactions of adhesive type (liquid to surface) and cohesive type (liquid to liquid).
The term “contact angle” or “wetting angle” as used herein refers to the angle between the surface of the liquid and the outline of the contact surface. It is a measure of the wettability of a substrate by a liquid, and can be quantified by the Laplace-Young fitting method, for example as disclosed in Hoorfar, M. et al. (Advances in colloid and interface science 2006).
The term “sheet resistance” or “resistivity” as used herein refers to the resistance of thin films that are nominally uniform in thickness. It can be quantified by Van der Pauw method, for example as described in Van der Pauw L. J. (Philips Res. Rep 1958). Commonly, resistivity is in units of Ω·m (resulting from Ω·m2/m (Ω·area/length)). When divided by the sheet thickness (m), the units are the term “(m/m)” cancels, but represents a special “square” situation yielding an answer in ohms. Thus, sheet resistance is measured in ohms per square (Ω/sq or Ohm/sq). Sheet resistance may be used to assess antistatic properties.
The term “abrasion resistance” as used herein refers to the ability of a surface to resist being worn away by rubbing or friction.
The term —(C1-Cn)alkyl (wherein n is e.g. 30, 15 or 6) refers to a saturated branched or linear hydrocarbon chain which contains from 1 to n (e.g. 30, 15 or 6) carbon atoms and only single bonds. Non-limiting examples of —(C1-Cn)alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, or hexyl. The term —O(C1-Cn)alkyl refers to an alkoxy group, wherein the alkyl part is as previously defined. Non-limiting examples of —O(C1-Cn)alkyl groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, or isobutoxy.
The term —(C3-C10)cycloalkyl refers to a saturated carbocyclic ring system which may be monocyclic or bicyclic and which contains from 3 to 10 carbon atoms. Examples include cyclopropane, cyclobutane, cyclopentane, cyclohexane or cyclooctane.
A halogen substituent means fluoro, chloro, bromo or iodo.
As used herein, the term “reactive functional group” refers to a functional group which can react under appropriate conditions to form a chemical bond with an atom or group of atoms that are not part of the reactive functional group, i.e., the functional groups present in the surface of the static dissipative material. The term “hydrolysable group” as used herein refers to a reactive functional group as previously defined which can be broken down, or undergo hydrolysis in the presence of water.
The expression “two or more reactive functional groups” means that the inorganic or organic moiety can have two or more, preferably with 2, 3 or 4 reactive functional groups. For the purposes of the invention, room temperature is 20-25° C.
As mentioned above, the invention relates to a modified static dissipative material, comprising a) a static dissipative material, and b) a plurality of inorganic or organic moieties having two or more reactive functional groups as defined herein, wherein the inorganic or organic moieties are chemically bonded to the static dissipative material. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the modified static dissipative material consists of a) a static dissipative material, and b) a plurality of inorganic or organic moieties having two or more reactive functional groups as defined herein.
The modified static dissipative materials of the present invention, particularly clays, can be prepared by functionalising unmodified static dissipative materials with certain organic and inorganic moieties.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material a) (i.e. the unmodified material) has a sheet resistance equal to or lower than 1012 Ohm/sq as measured by the Van der Pauw method when applied to a substrate. More particularly, it has a sheet resistance from 105 to 1010 Ohm/sq, more particularly from 107 to 109 Ohm/sq, as measured by the Van der Pauw method.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of a clay, a metal oxide, a metal, carbon black, graphite and graphene.
Some examples of metal oxides that may be used as static dissipative material include, without limitation, iron oxide, titanium oxide, tin dioxide, zinc oxide, tin dioxide powder doped with antimony, tin oxide doped with tantalum, niobium or phosphorus.
Some examples of metals that may be used as static dissipative material include without limitation gold, silver, copper, nickel, chromium, palladium, aluminium, tungsten, molybdenum, or platinum.
More particularly, the static dissipative material is a clay. Thus, the invention also relates to a modified clay comprising:
In particular, the clay a) has a sheet resistance equal to or lower than 1012 Ohm/sq as measured by the Van der Pauw method when applied to a substrate. In particular, the modified static dissipative material has a static contact angle of water from 50 to 130° as measured by the Laplace-Young fitting method when applied to a substrate.
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the inorganic or organic moieties are chemically bonded to the static dissipative material through a —O—Si— bond. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the inorganic or organic moieties are chemically bonded to the static dissipative material through a —O—P— bond. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the inorganic or organic moieties are chemically bonded to the static dissipative material through a —O—C— bond, more particularly a —O—C(O)—. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the inorganic or organic moieties are chemically bonded to the static dissipative material through a —O—C— bond, more particularly a —O—CH2—C(OH)—. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is metal, and the inorganic or organic moieties are chemically bonded to the static dissipative material through through a metal-S-bond. More particularly the metal is selected from the group consisting of gold and silver.
Clays are mineral silicates which have accessible hydroxyl groups which may be replaced by inorganic or organic compounds having reactive functional groups.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the clay is a natural or synthetic clay, more particularly a synthetic clay.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the clay is a nano-clay.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the clay is selected from the group consisting of laponites, smectites, montmorillonites, bentonites, kaolinites, hectorites, and halloysites, more particularly the clay is a smectite, even more particularly is a laponite.
Laponites have a structure and composition closely resembling the natural clay mineral hectorite. Laponites are layered hydrous magnesium silicates which belong to the family of (2:1) phyllosilicates. They are built up of sheets of octahedrally coordinated magnesium oxide sandwiched between two parallel sheets of tetrahedrally coordinated silica (
In water laponite forms a colloidal dispersion of charged disk-like particles which have a diameter of about 25 nm and a thickness of about 1 nm with negative charges on the faces and positive charges on the rims (
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is in the form of disk-like particles, more particularly having a diameter from 10 to 50 nm and a thickness from 0.5 to 2 nm, even more particularly with negative charges on the faces and positive charges on the rims.
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the clay has a unit cell formula of Na0.7Si8Mg5.5Li0.3O20(OH)4.
Laponites are sold by Rockwood Additives. Non limiting examples of marketed laponites which may be used in the present invention include Laponite XLG®, Laponite RDS®, Laponite JS®, and Laponite RD®. In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the clay is Laponite XLG®.
As mentioned above, the modified static dissipative material of the present invention, particularly a clay, comprises a plurality of inorganic or organic moieties having one or more reactive functional groups which are chemically bonded to the static dissipative material. When the static dissipative material is a clay, the inorganic or organic moieties are chemically bonded to the clay. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the reactive functional groups are functional groups which are able to form a chemical bond with an atom or group of atoms that are present in the surface of the static dissipative material. More particularly, each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the static dissipative material. In a more particular embodiment, each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the static dissipative material through at least one of its reactive functional groups. In another more particular embodiment, each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the static dissipative material through only one of its reactive functional groups.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the reactive functional groups are functional groups which are able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied. More particularly, each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied. In a more particular embodiment, each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied through at least one of its reactive functional groups. In another more particular embodiment, each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied through one of its reactive functional groups.
According to one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic moieties comprise one or more fluoro atoms.
The reactive functional groups of the inorganic or organic moieties can be independently selected from the group consisting of a silyl group, a phosphonyl group, a biphosphonyl group, thiol (—SH), a carboxyl group, and an epoxy group.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the reactive functional groups are hydrolisable groups, more particularly the hydrolysable groups are selected from the group consisting of a silyl group, a phosphonyl group, a biphosphonyl group, and a carboxyl group.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic moieties have two reactive functional groups, more particularly one of the two reactive functional groups is attached to the static dissipative material, and the other one is placed at the end of the moiety (i.e. far from the surface of the static dissipative material), and is able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the silyl group has the formula:
wherein R1-R3 are independently selected from the group consisting of halogen, hydroxyl, —(C1-C30)alkyl, and —O(C1-C30)alkyl, with the condition that at least one of R1-R3 is hydroxyl or —O(C1-C30)alkyl. More particularly, R1-R3 are independently selected from the group consisting of halogen, hydroxyl, —(C1-C30)alkyl, and —O(C1-C30)alkyl, with the condition that at least one of R1-R3 is hydroxyl or —O(C1-C30)alkyl. Even more particularly, R1-R3 are independently selected from the group consisting of halogen, hydroxyl, —(C1-C6)alkyl, and —O(C1-C6)alkyl, with the condition that at least one of R1-R3 is hydroxyl or —O(C1-C6)alkyl.
The groups R1-R3 may be the same or different. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, R1-R3 are independently selected from the group consisting of halogen; and —O(C1-C30)alkyl, more particularly —O(C1-C30)alkyl, and even more particularly —O(C1-C6)alkyl. In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, R1-R3 are the same and are halogen or —O(C1-C30)alkyl. More particularly, R1-R3 are the same and are —O(C1-C30)alkyl, even more particularly —O(C1-C30)alkyl, and even more particularly —O(C1-C6)alkyl.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the phosphonyl and biphosphonyl groups have the formulas:
respectively, wherein R4-R9 are independently selected from the group consisting of hydrogen and —(C1-C30)alkyl. The groups R4-R5 or R6-R9 may be the same or different. More particularly, —(C1-C30)alkyl in R4-R9 is —(C1-C30)alkyl and even more particularly —(C1-C6)alkyl.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the carboxyl group has the formula
wherein R10 is independently selected from the group consisting of hydroxyl, halogen, and —O(C1-C30)alkyl. More particularly, —O(C1-C30)alkyl in R10 is —O(C1-C30)alkyl and even more particularly —O(C1-C6)alkyl.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the epoxy group has the formula:
and can be unsubstituted or optionally substituted in any epoxy carbon atom.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, each reactive functional group is independently selected from the group consisting of a silyl group of the formula:
a phosphonyl group of the formula:
a biphosphonyl group of the formula:
a thiol (—SH);
a carboxyl group of the formula:
and an epoxy group;
wherein R1-R10 are independently as previously defined.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, at least one of the reactive functional groups, and particularly each of the reactive functional groups, has the formula:
wherein R1-R3 are independently as previously defined, more particularly R1-R3 are selected from methoxy, ethoxy, propoxy and chloro, and even more particularly are ethoxy.
The moieties having reactive functional groups, in particular moieties comprising one or more fluoro atoms, may be inorganic or organic moieties having low or high molecular weight. They can be discrete molecules or polymers.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the moieties having reactive functional groups, in particular moieties comprising one or more fluoro atoms, have a molecular weight (Mw) equal to or lower than 50000 g/mol.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the moieties having reactive functional groups, in particular moieties comprising one or more fluoro atoms, are inorganic. In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the moieties having functional groups, in particular moieties comprising one or more fluoro atoms, are organic.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the moieties having two or more reactive functional groups, in particular moieties comprising one or more fluoro atoms, comprise a carbon chain comprising at least one —(CR14R15)— moiety wherein R14 and R15 are independently selected from the group consisting of H and F. More particularly, at least one of R14 or R15 is F.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the moieties having two or more reactive functional groups, in particular moieties comprising one or more fluoro atoms, comprise a carbon chain comprising at least one —(CR14R15)—O— moiety wherein R14 and R15 are independently selected from the group consisting of H and F. More particularly, at least one of R14 or R15 is F.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the moieties having two or more reactive functional groups, in particular moieties comprising one or more fluoro atoms, are polymer moieties, more particularly fluoropolymer moieties, and even more particularly perfluoropolyether moieties.
For the purposes of the invention, a fluoropolymer is a fluorocarbon-based polymer with multiple carbon-fluorine bonds. Perfluoropolyethers (PFPEs) are a class of polymers which consists of carbon, oxygen and fluorine atoms. The molecular structure can be branched, linear, or a combination thereof depending on the desired physical properties. PFPEs typically have molecular weights from 500 to 100000 g/mol.
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the perfluoropolyether moieties comprise the repetitive unit of the formula —(CxF2xO)y—, wherein x is a value from 1 to 6, and y is a value from 2 to 500. More particularly, the perfluoropolyether moieties comprise a repetitive unit of the formula:
wherein m is from 0 to 500 and n is from 0 to 500, with the condition that when one of m or n is 0, then the other of m or n is other than 0.
In a more particular embodiment, the perfluoropolyether moieties comprise the following formula:
wherein m and n are as defined above.
In a more particular embodiment, the perfluoropolyether moieties comprise the following formula:
wherein m is from 100 to 400 and n is from 100 to 400, and each of the ends of the polymer are attached to a reactive functional group as defined herein. In an even more particular embodiment, m+n is a value from 9-13 and m/n is from 1-2. In another more particular embodiment, m+n is 40 and m/n is from 0.5-2.
In another more particular embodiment, the perfluoropolyether moieties comprise the following formula:
wherein m and n are as previously defined and p is from 1 to 20.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the compound having two or more reactive functional groups is a silicone polymer, more particularly, a silicone polymer which comprises a repetitive unit of the formula:
wherein R and R′ independently are —(C1-C30)alkyl or —(C3-C10)cycloalkyl, and z is a value from 10 to 50000.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic moieties having two or more reactive functional groups comprise a carbon chain comprising at least one —(CR12R13)— moiety wherein R12 and R13 are independently selected from the group consisting of H and F, more particularly wherein at least one of R12 or R15 is F, or a silicone polymer which comprises a repetitive unit of the formula:
wherein R and R′ are as previously defined.
As mentioned above the inorganic or organic compounds moieties are chemically bonded to the static dissipative material. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the modified static dissipative material is obtainable by chemically grafting an inorganic or organic compound having two or more reactive functional groups, to the static dissipative material, through at least one of the reactive functional groups and the functional groups present on the surface of the static dissipative material. In the case of a clay, the modified clay is obtainable by chemically grafting an inorganic or organic compound having two or more reactive functional groups, to the clay through at least one of the reactive functional groups and the hydroxyl groups present on the surface of the clay. The two or more reactive functional groups inorganic or organic compound are selected from the group consisting of a silyl group, a phosphonyl group, a biphosphonyl group, thiol, a carboxyl group, and an epoxy group, as defined herein.
In the case of a clay, when the reactive functional group which reacts with the clay is a silyl group, the chemical bond formed between the static dissipative material and the inorganic or organic compound is a —O—Si— bond. When the reactive functional group which reacts with the clay is a phosphonyl group or a biphosphonyl group, the chemical bond formed between the static dissipative material and the inorganic or organic compound is a —O—P— bond. When the reactive functional group which reacts with the clay is a carboxyl group or an epoxy group, the chemical bond formed is a —O—C— bond. Accordingly, in one embodiment, the inorganic or organic moieties are attached to the static dissipative material through —O—Si—, —O—P—, metal-S- or —O—C-chemical bonds. More particularly, the inorganic or organic moieties are attached to the static dissipative material, particularly a clay, through —O—Si-chemical bonds.
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the reactive functional group comprises a silyl group, in particular a silyl group which is attached to the static dissipative material through a —O—Si— bond. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the reactive functional group comprises a phosphonyl group, in particular a phosphonyl group which is attached to the static dissipative material through a —O—P— bond. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
The interaction between a static dissipative material selected from the group consisting of clay, carbon black, graphite and graphene and a bisphosphonate can be carried out under reaction conditions well-known in the art such as for example as described in Journal of Materials Science: Materials in Medicine 2020, 31(11), 1-13).
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the reactive functional group comprises a carboxyl group, in particular a carboxyl group which is attached to the static dissipative material through a —O—C— bond, more particularly a —O—C(O)—. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is selected from the group consisting of clay, carbon black, graphite and graphene, and the reactive functional group comprises an epoxy group, in particular a carboxyl group which is attached to the static dissipative material through a —O—C— bond, more particularly a —O—CH2—C(OH)—. In particular, carbon black, graphite and graphene are oxidised carbon black, oxidised graphite and oxidised graphene, respectively.
The reaction between a static dissipative material selected from the group consisting of clay, carbon black, graphite and graphene with an epoxide can be carried out under reaction conditions well-known in the art such as for example as described in Current Organic Chemistry 2013, 17(9), 900-912.
Oxidation of carbon black, graphite and graphene may be performed with an acid treatment such as HNO3, a termic treatment or plasma.
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the static dissipative material is metal, and the reactive functional group comprises a thiol group, in particular a thiol group which is attached to the static dissipative material through a metal-S-bond. More particularly the metal is selected from the group consisting of gold and silver.
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic compound used to functionalise the static dissipative materials has two reactive functional groups as previously defined. In a more particular embodiment, the two reactive functional groups are placed each at one end of the compound. In another more particular embodiment, the two reactive functional groups are the same.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, each reactive functional group of the inorganic or organic compound used to functionalise the static dissipative materials is independently selected from the group consisting of a silyl group of the formula:
a phosphonyl group of the formula:
a biphosphonyl group of the formula:
a thiol (—SH);
a carboxyl group of the formula:
and an epoxy group;
wherein R1-R10 are independently as previously defined.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the reactive functional groups of the inorganic or organic compound, in particular comprising one or more fluoro atoms, used to functionalise the static dissipative materials, particularly two reactive functional groups, and more particularly two reactive functional groups placed each at one end of the compound, have the formula:
wherein R1-R3 are independently as previously defined.
Further embodiments indicated above for the inorganic or organic moieties also apply to the inorganic or organic compounds.
In one embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic compound used to functionalise the static dissipative materials is a perfluoropolyether which has the formula:
wherein m is from 100 to 400 and n is from 100 to 400.
The above polymer is commercially available under the name Fluorolink® S10 (Solvay Solexis).
In another embodiment of the invention, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic compound used to functionalise the static dissipative materials is a perfluoropolyether which has the formula:
wherein m, n and p are as previously defined.
The above polymer is commercially available under the name Fluorolink® P54 (Solvay Solexis).
As previously mentioned, the static dissipative materials of the invention are produced by functionalising unmodified static dissipative materials, with certain inorganic or organic compounds through reactive functional groups contained in these compounds by methods well-known in the art. The skilled person will be able to determine in each case the type of reaction to be used depending on the static dissipative materials and the inorganic or organic functionalising compound.
The reactive functional groups (at least two and particularly, each placed at one end of the molecule) serve both to anchor the compound to the static dissipative material as well as to the substrate when the latter is coated thereby improving its adhesion to the substrate. For the purposes of the invention the term “functionalisation” or “modification” refers to the weight/weight % of the inorganic or organic moieties with respect to the static dissipative materials. The degree of functionalisation may be measured by thermal gravimetric analysis (TGA).
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the weight of the inorganic or organic moieties with respect to the weight of the static dissipative material, in particular the clay, is at least 3% (i.e. functionalisation of 3%) or at least 5% (i.e. functionalisation of 5%) as measured by thermal gravimetric analysis. More particularly, the weight of the inorganic or organic moieties with respect to the weight of the static dissipative material is about 3%, about 12%, about 25%, about 41%, or about 48% as measured by thermal gravimetric analysis.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the weight of the inorganic or organic moieties with respect to the weight of the static dissipative material, in particular the clay, is from 5% to 100%, from 5% to 75%, from 10% to 65%, from 35 to 65%, from 35 to 50%, and even more particularly about 41%.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the modified static dissipative material has a static contact angle of water from 50° to 130°, more particularly from 60° to 120°, and even more particularly about 114°, as measured by the Laplace-Young fitting method when applied to a substrate.
The modified static dissipative materials of the present invention may be formulated into coating compositions to protect a variety of substrates. Thus, the invention also relates to coating compositions comprising the modified static dissipative material as defined herein and one or more carriers or additives. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition consists of the modified static dissipative material as defined herein and one or more carriers or additives.
Non-limiting examples of additives include pigments, UV shielding agents, antimicrobial agents, mechanical enhanced additives, anti-fouling agents, wetting agents, thickening agents, hardening agents, toughening agents, plasticizers and stabilizers.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition is a dispersion of the modified static dissipative material in a solvent. Any solvent may be used provided that is capable of dispersing modified static dissipative material. In a more particular embodiment, the solvent is selected from the group consisting of a (C1-C6)alcohol, water and mixtures thereof. In another particular embodiment, the composition contains the modified static dissipative material in an amount from 0.1 to 50%, more particularly from 0.5 to 25%, even more particularly from 1 to 5%, by weight with respect to the total volume of the composition.
It also forms part of the invention a process for the preparation of a coating composition comprising the modified static dissipative material as previously defined which comprises dispersing the modified static dissipative material in a suitable solvent, in particular using the solvents and amounts as previously defined, and optionally adding one or more additives.
In a particular embodiment, the invention relates to a process for the preparation of a coating composition as previously defined, which comprises:
The low affinity for liquids of the coating compositions of the present invention, i.e., their liquid repellence capability, is illustrated in
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition has a static contact angle of water from 50 to 130°, more particularly from 60° to 120°, and even more particularly about 114°, as measured by the Laplace-Young fitting method when applied to a substrate.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition has a static contact angle of hexadecane from 30° to 80°, more particularly from 35° to 70°, and even more particularly about 67°, as measured by the Laplace-Young fitting method when applied to a substrate.
The compositions of the invention also show repellency for solids (dust), i.e. antistatic properties, as illustrated in
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition has a surface free energy from 5 to 50 mN/m, more particularly from 7 to 30 mN/m, and even more particularly about 11 mN/m, as measured by the Fowkes model when applied to a substrate.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition has a sheet resistance from 1.0·107 to 2.0·109 Ohm/sq, more particularly from 5.0·107 to 1.0·109 Ohm/sq, and even more particularly about 8.2·108 Ohm/sq, as measured by the Van der Pauw method when applied to a substrate.
One of the most demanded requirements for practical application of coatings is their mechanical resistance. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition has a static contact angle of water as measured by the Laplace-Young fitting method which does not vary more than//varies less than 10%, more particularly less than 7%, before and after 50 abrasion cycles when applied to a substrate.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition has coating thickness as measured by FESEM micrographs which does not vary more than//varies less than 10%, more particularly less than 5%, before and after 50 abrasion cycles when applied to a substrate.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the coating composition is transparent, i.e. the transmittance (%) in in the visible region (approx. 380-750 nm) is higher than about 80%.
According to a third aspect of the invention a process for the preparation of the modified static dissipative material as previously defined is provided. This process comprises the following steps:
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, step a) is carried out by adding the unmodified static dissipative material in small amounts, in particular under stirring until their complete dispersion, more particularly under stirring for a period from 30 min to 24 h.
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic compound used of step b) is slowly incorporated to the dispersion of step a).
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the inorganic or organic compound having two or more reactive functional groups is added as a solution. More particularly, the solvent of the solution containing an inorganic or organic compound used in step b) is a (C1-C6)alcohol, such as ethanol or isopropanol, more particularly isopropanol.
The reaction may take place at room temperature or by heating. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, after step b) the mixture is heated at a temperature from 40° C. to 100° C., more particularly at a temperature of about 60° C., even more particularly under stirring for a period of time from 30 min to 24 h.
If an excess of inorganic or organic compound having two or more reactive functional groups is used in step b), the unreacted inorganic or organic compound may be removed from the reaction mixture after step b).
If a solvent is used in step b) then the solvent can be also after step b).
In another embodiment, optionally in combination with one or more features of the various embodiments described above or below, the process further comprises step c) after step b) of removing the unreacted inorganic or organic compound. In one embodiment, step c) is carried out by centrifugation, in particular at about 3500 rpm for a period of time from 20 to 60 min, and removing the supernatant.
Optionally, after step b) or step c) the obtained modified static dissipative material can be purified by redispersing it in a suitable solvent and removing the solvent together with the unreacted inorganic or organic compound and solvent. In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the solvent is selected from a (C1-C6)alcohol, water and mixtures thereof. More particularly, the solvent is a mixture of an alcohol and water, even more particularly the (C1-C6)alcohol is isopropanol, and even more particularly, the solvent is a mixture is isopropanol and water 1:1.
Moreover, the invention is also related to the modified static dissipative material as previously defined which is obtainable by chemically grafting a plurality of inorganic or organic moieties having two reactive functional groups to the static dissipative material through one of the reactive functional groups, wherein each reactive functional group is independently selected from the group consisting of a silyl group, a phosphonyl group, a biphosphonyl group, thiol, a carboxyl group, and an epoxy group.
More particularly, the invention refers to the modified static dissipative material as previously defined which is obtainable by the process comprising the following steps:
The expression modified static dissipative material “obtainable by” is used herein for defining the modified static dissipative material by its preparation process and refers to the product that can be obtained through the preparation process which comprises the steps mentioned herein. For the purposes of the invention, the expressions “obtainable”, “obtained” and similar equivalent expressions are used interchangeably and, in any case, the expression “obtainable” encompasses the expression “obtained”.
A fourth aspect of the invention relates to a process for coating at least part of the surface of a substrate which comprises applying the coating composition as previously defined to at least part of the surface of a substrate. Non-limiting examples of substrates which can be coated with the coating compositions of the invention include for example glass, metal, alloy, synthetic polymer, natural polymer, ceramic, or the like.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the process comprises forming a film, particularly a homogeneous and continuous film, over at least part of the surface of the substrate.
These films can be prepared by conventional coating methods such as casting, bar-coating, dip-coating, blade-coating, or spin-coating techniques.
In one embodiment, optionally in combination with one or more features of the various embodiments described above or below, the process comprises using the bar-coating technique.
After applying the coating to the substrate, a final curing step may optionally be performed, particularly at a temperature from room temperature to 100° C., more particularly for a period of time from 0 min to 24 h.
Optionally, prior to the coating deposition, the substrate may be cleaned, and/or activated. Typically, cleaning may comprise a washing step using soap and rinsing the substrate with thoroughly water. Additionally, substrates may be immersed once or successively in a solvent or a mixture of solvents such as water, isopropanol, acetone, or mixtures thereof, in particular under sonication. Activation of the substrate is used with the aim to generate hydroxyl groups in the substrate surface prone to promote chemical bonds between the surface and the reacting groups (e.g. silanol groups) present in the inorganic or organic compound. Activation may be carried out by immersing a substrate, in particular a cleaned substrate, in 10 wt. % NaOH aqueous solution in the case of glass or by treating it with oxygen plasma in the case of PC or PVC.
Thus, in a particular embodiment, the invention relates to a process for coating at least part of the surface of a substrate, which comprises:
An aspect of the present invention also relates to the article of manufacture coated with the coating composition as previously defined.
Throughout the description and claims the word “comprise” and variations of the word, are not intended to exclude other technical features, additives, components, or steps. Furthermore, the word “comprise” encompasses the case of “consisting of”. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. The following examples and drawings are provided by way of illustration, and they are not intended to be limiting of the present invention. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments described herein.
Laponite grades XLG from Rockwood Additives Ltd. was kindly provided by Azelis and Comindex, respectively. Laponite is a uniform disc-shaped synthetic clay with disc diameters of 25 nm and thicknesses of 1 nm. Fluorolink S10 was purchased from Acota. Isopropanol (99.5%) was acquired from Scharlab. All chemicals were used as received. Deionized water with a conductivity <1 μS was used in all experiments. Glass substrates with 1 mm thickness were obtained from Deltalab S. L. with reference D100001 and cut into 25×25 mm squares. Polycarbonate (PC) sheets acquired from sefar maissa and cut into 25×25 mm squares.
Fourier transform infrared spectra (FT-IR) of the solids were obtained by Attenuated Total Reflectance (ATR) technique with a Jasco 4100 FTIR, from 400 cm-1 to 4000 cm-1.
Thermal gravimetric analysis (TGA) was carried out on a TA instruments Q500 thermobalance. Samples were heated at a rate of 10° C./min from ambient temperature to 700° C. under a nitrogen flow of 60 mL/min.
Morphological properties of the film were analyzed using ULTRA plus ZEISS field emission scanning electron microscope (FE-SEM).
KSV CAM 200 and Attension Theta Lite Optical tensiometers were used to determine the static contact angles and the SFE of the films. Solvent droplets were placed at a minimum of three different areas of each surface. The static contact angles were recorded using the Laplace-Young fitting method. SFE of coatings was calculated according to the Fowkes model using water and ethylene glycol as polar liquids and diiodomethane as non-polar liquid.
Sheet resistance of the films was measured at atmospheric pressure and room temperature conditions using a Keithley Semiconductor Characterization System 4200-SC with a four-point probe.
Functionalisation of XLG laponites (Lap) was carried out by chemically grafting PFPE S10 on Lap surface. Briefly, 25 mL of deionized water were introduced to a 100 mL round-bottomed flask and 1 g of Lap was added in small amounts under vigorous stirring until their complete dispersion. After stirring for 1 h, an isopropanol (20 g) solution containing varying amounts (0.05-1 g) of S10 to produce different S10-Lap functionalisation degrees was slowly incorporated to the dispersion. The mixture was remained under stirring and refluxed at 60° C. overnight. After cooling to room temperature, the whitish gel obtained was centrifuged at 3500 rpm during 20 min. The supernatant was removed and the gel redispersed in a water/isopropanol (1/1) mixture followed by centrifugation twice in order to remove the unbounded material. Subsequently, the gel was redispersed in water/isopropanol (1/1) to obtain 25 mL of 4% (w/v) Lap dispersion.
The degree of functionalisation of the obtained modified laponites as measured by TGA is shown in the table 1 below:
Prior to the coating deposition, glass and PC substrates were cleaned and activated. The cleaning process involves a washing step using soap and rinsed with thoroughly water. After that, glass substrates were immersed in deionized water, isopropanol and acetone successively under sonication for 5 min each one. The same process was applied to PC substrates without the acetone immersion step. With the aim to generate hydroxyl groups in the substrate surface prone to promote chemical bonds between the surface and the silanol groups present in the PFPE molecules, the cleaned substrates were activated by immersion in 10 wt. % NaOH aqueous solution in the case of glass while the PC ones were treated with oxygen plasma during 5 min (40 kHz, 200 W).
The coatings were characterised by ATR-FTIR and TGA (
The wettability properties of the films prepared from the formulations containing different rates of S10/Lap were examined through contact angle (CA) measurements using water and hexadecane as probe liquids (
Another important parameter directly related to the interaction that a surface establishes with a liquid is the surface free energy (SFE) which is defined by the Fowkes model as the sum of its polar and non-polar (dispersive) contribution.
In order to verify the antistatic effect of Lap on the developed coatings containing different amounts of S10 their sheet resistance was measured by Van der Pauw method (
In order to verify the self-cleaning performance of the coatings of the invention their ability to repel liquids was evaluated. The formulation with a S10/Lap rate of 41 wt. % was selected. Water and olive oil were used as polar and non-polar representative contaminant liquids, respectively. The liquid repellence test was carried out by two ways. The first one involved the deposition of water droplets on the surface of the samples previously tilted around 20°.
As can be seen in
Once demonstrated the liquid repellency capabilities of the coating of the invention, the adhesion of carbon black particles acting as solid fouling agent was evaluated (
In order to evaluate the robustness of the developed coating rub abrasion essays were performed with a crockmeter using a dry wipe as abrasive agent and applying a pressure of 1 kPa. The influence of abrasion on the coating was monitored by water CA measurements after 2, 10, 20 and 50 rub cycles. As shown in Table 2, the CA remains almost constant after 25 abrasion cycles proving that the coating properties are not worsened by the abrasion action. Additionally, it is noted that the coating thickness suffered no significant alteration upon being abraded repeatedly as displayed the cross-section FESEM micrographs (
The same rub abrasion essays were performed with the film disclosed in Fenero M. et al (2017) consisting of a 7:3 mixture of unmodified laponites and modified laponites with a degree of functionalisation of 60%. As shown by the cross-section FESEM micrographs after 5 abrasion cycles (
For reasons of completeness, various aspects of the invention are set out in the following numbered clauses:
Clause 1. A modified static dissipative material comprising:
Clause 2. The modified static dissipative material according to clause 1, which consists of a) and b).
Clause 3. The modified static dissipative material according to any of the clauses 1-2, inorganic or organic moieties comprise one or more fluoro atoms.
Clause 4. The modified static dissipative material according to any of the clauses 1-3, wherein the static dissipative material is in the form of disk-like particles, more particularly having a diameter from 10 to 50 nm and a thickness from 0.5 to 2 nm, even more particularly with negative charges on the faces and positive charges on the rims.
Clause 5. The modified static dissipative material according to any of the clauses 1-4, wherein the static dissipative material a) has a sheet resistance equal to or lower than 1012 Ohm/sq, more particularly from 105 to 1010 Ohm/sq, more particularly from 107 to 109 Ohm/sq, as measured by the Van der Pauw method when applied to a substrate.
Clause 6. The modified static dissipative material according to any of the clauses 1-5, wherein the modified static dissipative material has a static contact angle of water from 50 to 130°, more particularly from 60° to 120°, and even more particularly about 114°, as measured by the Laplace-Young fitting method when applied to a substrate.
Clause 7. The modified static dissipative material according to any of the clauses 1-6, wherein the static dissipative material is selected from the group consisting of a clay, a metal oxide, a metal, carbon black, graphite and graphene.
Clause 8. The modified static dissipative material according to clause 7, wherein the static dissipative material is a clay, more particularly a laponite.
Clause 9. The modified static dissipative material according to any of the clauses 1-8, wherein the weight of the inorganic or organic moieties with respect to the weight of the static dissipative material is at least 3%, or at least 5%, or from 10% to 65%, or from 35 to 50% as measured by thermal gravimetric analysis.
Clause 10. The modified static dissipative material according to any of the clauses 1-9, wherein each of the inorganic or organic moieties is chemically bonded to the static dissipative material through at least one of its reactive functional groups or alternatively through only one of its reactive functional groups.
Clause 11. The modified static dissipative material according to any of the clauses 1-10, wherein each of the inorganic or organic moieties is able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied through at least one of its reactive functional groups.
Clause 12. The modified static dissipative material according to any of the clauses 1-11, wherein the inorganic or organic moieties comprise two reactive functional groups.
Clause 13. The modified static dissipative material according to clause 12, wherein each of the two reactive functional groups are placed at one end of the moiety.
Clause 14. The modified static dissipative material according to any of the clauses 12-13, wherein each of the inorganic or organic moieties is chemically bonded to the static dissipative material through one of the two reactive functional groups, and is able to form a chemical bond with an atom or group of atoms that are present in the surface of the substrate to which the coating is applied through the other of the two reactive functional groups.
Clause 15. The modified static dissipative material according to any of the clauses 1-14, wherein each reactive functional group is independently selected from the group consisting of a silyl group of the formula:
wherein R1-R3 are independently selected from the group consisting of halogen, hydroxyl, —(C1-C30)alkyl, and —O(C1-C30)alkyl, with the condition that at least one of R1-R3 is hydroxyl or —O(C1-C30)alkyl;
a phosphonyl group of the formula:
wherein R4-R5 are independently selected from the group consisting of hydrogen and —(C1-C30)alkyl;
a biphosphonyl group of the formula:
wherein R6-R9 are independently selected from the group consisting of hydrogen and —(C1-C30)alkyl;
a thiol;
a carboxyl group of the formula:
wherein R10 is independently selected from the group consisting of hydrogen, halogen, and —O(C1-C30)alkyl; and
an epoxy group.
Clause 16. The modified static dissipative material according to clause 15, wherein each reactive functional group has the formula:
wherein R1-R3 are independently selected from the group consisting of halogen, hydroxyl, —(C1-C30)alkyl, and —O(C1-C30)alkyl, with the condition that at least one of R1-R3 is hydroxyl or —O(C1-C30)alkyl.
Clause 17. The modified static dissipative material according to any of the clauses 1-16, wherein the inorganic or organic moieties are fluoropolymer moieties.
Clause 18. The modified static dissipative material according to clause 17, wherein the fluoropolymer moieties are perfluoropolyether moieties comprising the repetitive unit of formula:
wherein m is from 0 to 500 and n is from 0 to 500, with the condition that when one of m or n is 0, then the other of m or n is other than 0.
Clause 19. The modified static dissipative material according to any of the clauses 1-18, wherein the inorganic or organic moieties are attached to the static dissipative material through —O—Si—, —O—P—, metal-S- or —O—C-chemical bonds.
Clause 20. A coating composition comprising the modified static dissipative material as defined in any of the clauses 1-19, and one or more carriers or additives.
Clause 21. A process for the preparation of the modified static dissipative material as defined in any of the clauses 1-19, which comprises the following steps:
Clause 22. A process for coating a substrate which comprises applying a coating composition as defined in any of the clause 20 to at least part of the surface of a substrate.
Clause 23. An article of manufacture coated with the coating composition as defined in clause 20.
Number | Date | Country | Kind |
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20382700.1 | Jul 2020 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/071277 | 7/29/2021 | WO |