WO2023104742A1

WO2023104742A1 - Conductive lubricating greases

Info

Publication number: WO2023104742A1
Application number: PCT/EP2022/084478
Authority: WO
Inventors: Lionel BOSCO
Original assignee: Totalenergies Onetech
Priority date: 2021-12-06
Filing date: 2022-12-05
Publication date: 2023-06-15
Also published as: FR3129949A1

Abstract

The present invention relates to the use of a sulfonate additive for increasing the electrical conductivity of a grease composition comprising at least one base oil and at least one thickener. The invention also relates to a grease composition comprising at least one base oil, at least one polyurea thickener and at least one sulfonate additive.

Description

Title: Conductive lubricating greases.

The present invention relates to the field of greases, in particular for electric motors, and more specifically for electric or hybrid vehicles.

Technical area

There are many applications where liquid lubricants are unsuitable because they “drift” from the lubrication point. These are in particular rolling and sliding bearings, open gears, wire ropes and chain drives, and more generally applications that do not include a sealing system.

For these applications, lubricating greases are used, which are solid or semi-fluid substances resulting from the dispersion of a thickener in a liquid lubricant, optionally incorporating additives which give them specific properties.

Thickeners can be organic or inorganic compounds.

Among the organic thickeners used in the manufacture of greases, mention may in particular be made of metallic salts of fatty acids and polycarbamides (polyureas).

In addition to its lubricating function, the grease also serves as a sealing agent to prevent the entry of contaminants or external pollutants, which can cause premature failure of the grease and the lubricated equipment.

In the context of certain applications, in particular electric motors, and in particular in electric motors, greases are subjected to high temperatures and high speeds and must therefore be able to withstand these high stresses for as long as possible to avoid failure.

State of the art greases comprising a base oil and a thickener, in particular a thickener of the polyurea type, sometimes have insufficient conductivity for certain applications.

It is therefore an object of the present invention to provide a grease composition having a higher conductivity, in particular for electric motor applications, and in particular for electric or hybrid vehicles. Summary of the invention

More specifically, the present invention relates to the use of a sulfonate additive to increase the electrical conductivity of a grease composition comprising at least one base oil and at least one thickener.

Preferably, the thickener is chosen from fatty acid metal salts and polyureas, preferably from polyureas, more preferably from diureas.

Preferably, the sulphonate additive is chosen from metal sulphonate salts. Preferably, the metal salt of the sulphonate is chosen from calcium salts, sodium salts, lithium salts, barium salts, magnesium salts, zinc salts, preferably from calcium salts, sodium salts, lithium salts, magnesium salts, zinc salts, more preferably from calcium salts, sodium salts, and advantageously from calcium salts.

Preferably, the sulphonate additive is chosen from sulphonates comprising at least one aromatic group optionally substituted by one or more aliphatic groups.

Preferably, the sulphonate additive is chosen from sulphonates comprising at least one naphthalene group optionally substituted by one or more aliphatic groups.

Preferably, the sulphonate additive is chosen from alkylnaphthalene sulphonate, dialkylnaphthalene sulphonate, alkylnaphthalene sulphonate/carboxylate, dialkylnaphthalene sulphonate/carboxylate, the alkyl groups being preferably chosen from alkyl groups comprising from 1 to 24 carbon atoms, preferably 3 to 18 carbon atoms, more preferably 5 to 12 carbon atoms.

According to one embodiment, the sulfonate additive is added at a content ranging from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, relative to the total weight of the grease composition after addition sulfonate additive.

The invention also relates to a grease composition comprising, relative to the total weight of the grease composition:

- from 70 to 95% by weight of base oil(s),

- from 4 to 20% by weight of thickener(s) chosen from polyureas,

- from 0.1 to 10% by weight of sulfonate additive(s). Preferably, the sulphonate additive used in the grease composition according to the invention has one or more of the following characteristics: the sulphonate additive is chosen from metal sulphonate salts.

- the sulfonate additive is chosen from metal sulfonate salts, and optionally the metal salt of the sulfonate is chosen from calcium salts, sodium salts, lithium salts, barium salts, magnesium salts, salts zinc, preferably from calcium salts, sodium salts, lithium salts, magnesium salts, zinc salts, more preferably from calcium salts, sodium salts, and advantageously from salts calcium; and/or the sulphonate additive is chosen from sulphonates comprising at least one aromatic group optionally substituted by one or more aliphatic groups.

- the sulfonate additive is chosen from sulfonates comprising at least one aromatic group optionally substituted by one or more aliphatic groups; and or

- the sulfonate additive is chosen from sulfonates comprising at least one naphthalene group optionally substituted by one or more aliphatic groups; and or

- the sulphonate additive is chosen from alkylnaphthalene sulphonate, dialkylnaphthalene sulphonate, alkylnaphthalene sulphonate/carboxylate, dialkylnaphthalene sulphonate/carboxylate, the alkyl groups being preferably chosen from alkyl groups comprising from 1 to 24 carbon atoms, preferably from 3 to 18 carbon atoms, more preferably from 5 to 12 carbon atoms.

In the rest of the text, the expressions “between ... and . . . ", " from . . . to..." and "varying from... to..." are equivalent and are intended to mean that the terminals are included, unless otherwise stated.

Unless otherwise indicated, the quantities in a product are expressed by weight, relative to the total weight of the product.

detailed description The present invention relates to the use of a sulfonate additive to increase the conductivity of a grease composition comprising at least one base oil and at least one thickener.

Sulfonate additive

Within the meaning of the present invention, the sulfonate additive denotes a compound comprising at least one sulfonate group.

The sulphonate additive according to the invention may optionally be in the form of a sulphonate/carboxylate complex, in particular a sulphonate/salicylate complex.

The sulphonate additive used in the context of the present invention is preferably chosen from metal sulphonate salts.

Preferably, the metal salt of the sulphonate salt is chosen from calcium salts, sodium salts, lithium salts, barium salts, magnesium salts, zinc salts, preferably from calcium salts, sodium salts, lithium salts, magnesium salts, zinc salts, more preferably from calcium salts, sodium salts, and advantageously from calcium salts.

According to one embodiment, the metal content of the metal sulphonate additive ranges from 0.1 to 10% by weight, preferably from 0.5 to 8% by weight, more preferably from 1 to 5% by weight, based on the total weight of the sulfonate additive.

According to one embodiment, the sulphonate salt is chosen from sulphonates comprising at least one aromatic group optionally substituted by one or more aliphatic groups.

In the context of the present invention, the term “aromatic” denotes a group or compound comprising at least one aromatic ring. Among the aromatic groups, mention may be made of phenyl groups and naphthalene groups.

In the context of the present invention, the term “aliphatic” denotes a group or compound not comprising an aromatic ring. The aliphatic group can be linear, branched or cyclic, saturated or unsaturated, and can comprise one or more heteroatoms. Among the aliphatic groups, mention may be made of alkyl, alkenyl and cycloalkyl groups, said groups optionally comprising one or more heteroatoms, such as one or more oxygen and/or nitrogen atoms. According to one embodiment, the sulphonate additive is chosen from sulphonates comprising at least one aromatic group comprising from 6 to 12 carbon atoms substituted by one or more alkyl groups comprising from 1 to 24 carbon atoms.

According to a particularly preferred embodiment, the sulfonate additive is chosen from metal alkylnaphthalene sulfonate, dialkylnaphthalene sulfonate, alkylnaphthalene sulfonate/carboxylate, dialkylnaphthalene sulfonate/carboxylate, alkyl groups comprising from 1 to 24 carbon atoms and the content metal ranging from 0.1 to 10% by weight relative to the total weight of the sulfonate additive.

According to one embodiment, the sulphonate additive is chosen from alkylnaphthalene sulphonate and dialkylnaphthalene sulphonate, the alkyl groups being preferably chosen from alkyl groups comprising from 1 to 24 carbon atoms, preferably from 3 to 18 carbon atoms , more preferably from 5 to 12 carbon atoms.

According to a particular embodiment, the sulfonate additive is chosen from calcium dialkylnaphthalene sulfonate, the alkyl groups comprising from 5 to 12 carbon atoms and the calcium content ranging from 1 to 5% by weight relative to the total weight of the sulphonate additive.

Base oil(s)

The grease composition used according to the invention comprises one or more base oils, preferably in a content of at least 70% by weight, preferably ranging from 70 to 99% by weight, more preferably from 75 to 98% by weight, preferably 80 to 95% by weight, relative to the total weight of the fat composition.

These base oils can be chosen from the base oils conventionally used in the field of lubricating oils, such as mineral, synthetic or natural, animal or vegetable oils or mixtures thereof.

It can be a mixture of several base oils, for example a mixture of two, three, or four base oils.

The base oils of the grease compositions considered according to the invention may in particular be oils of mineral or synthetic origin belonging to groups I to V according to the classes defined in the API classification (or their equivalents according to the ATIEL classification) and presented in Table 1 below or mixtures thereof.

[Table 1]

Mineral base oils include all types of base oils obtained by atmospheric and vacuum distillation of crude oil, followed by refining operations such as solvent extraction, de-alpha removal, solvent dewaxing, hydrotreating, hydrocracking, hydroisomerization and hydrofinishing .

Blends of synthetic and mineral oils, which may be biosourced, can also be used.

There is generally no limitation as to the use of different base oils to produce the compositions used according to the invention, except that they must have properties, in particular in terms of viscosity, viscosity index, or resistance to oxidation, suitable for use for propulsion systems of an electric or hybrid vehicle.

The base oils of the compositions used according to the invention can also be chosen from synthetic oils, such as certain esters of carboxylic acids and alcohols, polyalphaolefins (PAO), and polyalkylene glycol (PAG) obtained by polymerization or copolymerization of alkylene oxides comprising from 2 to 8 carbon atoms, in particular from 2 to 4 carbon atoms.

The PAOs used as base oils are for example obtained from monomers comprising from 4 to 32 carbon atoms, for example from octene or decene. The weight average molecular weight of PAO can vary quite widely. Preferably, the weight-average molecular mass of the PAO is less than 600 Da. The weight-average molecular mass of the PAO can also range from 100 to 600 Da, from 150 to 600 Da, or even from 200 to 600 Da.

Advantageously, the base oil or oils of the grease composition used according to the invention can be chosen from group II or III base oils.

According to an alternative embodiment, the oil or base oils of the composition implemented according to the invention are chosen from polyalphaolefins (PAO), polyalkylene glycol (PAG) and esters of carboxylic acids and alcohols.

The base oil or oils preferably represent from 70 to 90% by weight, preferably from 75 to 85% by weight, of the total weight of the grease composition.

The additive grease composition according to the invention comprises at least one thickener, preferably chosen from fatty acid metal salts and polyureas.

By “polyureas” within the meaning of the present invention, it is appropriate to understand diureas, tetraureas, hexaureas, octaureas, and combinations thereof.

Among the metal salts of fatty acids, mention may be made of metal salts of lithium, such as 12-hydroxy lithium stearate.

According to one embodiment of the invention, the grease composition comprises, relative to the total weight of the grease composition, less than 1% by weight of 12-hydroxy calcium stearate and less than 1% by weight of calcium stearate , preferably less than 0.1% by weight calcium 12-hydroxystearate and less than 0.1% by weight calcium stearate, more preferably the grease composition is free of calcium 12-hydroxystearate and free of calcium stearate. Preferably, the grease composition comprises, relative to the total weight of the grease composition, less than 1% by weight of metal salt of stearic or hydroxystearic acid, preferably less than 0.1% by weight of metal salt of stearic or hydroxystearic acid, more preferably the fat composition is free of metal salt of stearic or hydroxystearic acid.

According to a preferred embodiment of the invention, the thickener used in the context of the use according to the invention is chosen from polyureas, preferably from diureas.

The polyureas can for example be obtained by reaction between one or more monoamines one or more diisocyanates. Among the diisocyanates which can be used, mention may be made of tolylene diisocyanate, diphenyl diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, hexane diisocyanate, decane diisocyanate, octadecane diisocyanate.

Among the monoamines which can be used, mention may be made of oleylamine, aniline, p-toluidine, stearylamine, octylamine, dodecylamine, hexadecylamine, cyclohexylamine, dicyclohexylamine.

The thickener or thickeners preferably represent from 5 to 20% by weight, preferably from 5 to 15% by weight, more preferably from 8 to 12% by weight, of the total weight of the grease composition.

Preferably, the sulphonate additive is added to the grease composition comprising the base oil(s) and the thickener(s) at a content ranging from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, relative to the total weight of the grease composition (after addition of the sulphonate additive).

The addition of the additive according to the invention makes it possible to improve the electrical conductivity of the grease composition.

Preferably, the resistivity at 100° C. of the grease composition is reduced by a factor greater than or equal to 10, preferably greater than or equal to 100, more preferably greater than or equal to 500, when the sulphonate additive is added. in a mixture comprising at least one base oil and at least one thickener.

Preferably, the resistivity at 100° C. of the grease composition is reduced by a factor greater than or equal to 10, preferably greater than or equal to 100, more preferably greater than or equal to 500, when the sulphonate additive is added. at a content of the order of 5% in a mixture comprising at least one base oil and at least one thickener.

The sulphonate additive defined in the invention also makes it possible to reduce the breakdown voltage of a grease composition comprising at least one base oil and at least one thickener, in particular a thickener of the polyurea type.

The sulphonate additive defined in the invention also makes it possible to improve the fatigue resistance of the grease composition. More particularly, a grease composition comprising a sulphonate additive as defined in the invention can retain its performance in terms of electrical conductivity over time. The grease composition whose conductivity is improved is preferably implemented in electric motors, in particular in electric motors of electric or hybrid vehicles.

An electric vehicle is a vehicle with an electric motor as the sole means of propulsion.

A hybrid vehicle is a vehicle comprising an electric motor and a combustion engine.

The invention also relates, according to another of its aspects, to a process for increasing the electrical conductivity of a grease composition, said process comprising a step of mixing at least one sulfonate additive, with at least one base and a thickener, the thickener preferably being a polyurea.

According to one embodiment, the method comprises a step in which the conductivity is increased. Preferably, in the context of the process of the invention, the resistivity at 100° C. of the grease composition is reduced by a factor greater than or equal to 10, preferably greater than or equal to 100, more preferably greater than or equal to to 500, when the sulphonate additive is added to a content of the order of 5%.

The grease composition obtained at the end of the use or the process according to the invention preferably has a resistivity at 100° C. of less than or equal to 1.0×10 ⁸ ohmmeters, preferably less than or equal to 5.0×10 ⁷ ohmmeters .

All of the characteristics and preferences described for the use according to the invention also apply to this process.

A subject of the present invention is also a grease composition comprising at least one base oil, at least one thickener chosen from polyureas and at least one sulphonate additive.

The grease composition according to the invention comprises, relative to the total weight of the grease composition: from 70 to 95% by weight, preferably from 75 to 90% by weight, of base oil(s), from 4 to 20% by weight, preferably from 5 to 15% by weight of thickener(s) chosen from polyureas, from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, of sulfonate additive(s).

The grease composition according to the invention comprises, relative to the total weight of the grease composition: from 70 to 95% by weight, preferably from 75 to 90% by weight, of base oil(s), of 4 to 20% by weight, preferably from 5 to 15% by weight of thickener(s) chosen from diureas, from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight sulfonate additive(s).

Preferably, the sulphonate additive of the grease composition according to the invention has one or more of the characteristics and preferences described above for the sulphonate additive.

Thus, according to one embodiment, the grease composition according to the invention comprises, relative to the total weight of the grease composition: from 70 to 95% by weight, preferably from 75 to 90% by weight, of oil (s) base, from 4 to 20% by weight, preferably from 5 to 15% by weight of thickener(s) chosen from diureas, from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight of sulfonate additive(s) comprising at least one aromatic group optionally substituted by one or more aliphatic groups.

According to a preferred embodiment, the grease composition according to the invention comprises, relative to the total weight of the grease composition: from 70 to 95% by weight, preferably from 75 to 90% by weight, of oil ( s) base, from 4 to 20% by weight, preferably from 5 to 15% by weight of thickener(s) chosen from diureas, from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight of sulphonate additive(s) comprising at least one naphthalene group substituted by one or more aliphatic groups, preferably by one or more alkyl groups having 1 to 24 carbon atoms or 3 to 18 carbon atoms.

According to one embodiment, the grease composition according to the invention comprises, relative to the total weight of the grease composition: from 75 to 90% by weight of base oil(s), from 5 to 15% by weight of thickener chosen from polyureas, from 0.5 to 5% by weight of sulphonate additive chosen from metal sulphonate salts comprising at least one naphthalene group substituted by one or more aliphatic groups, the salts being chosen from calcium salts , sodium salts, lithium salts, barium salts and magnesium salts.

Preferably, the base oil of the grease composition according to the invention has one or more of the characteristics and preferences described above for the base oil.

Preferably, the polyurea thickener of the grease composition according to the invention has one or more of the characteristics and preferences described above.

The grease composition according to the invention preferably has a resistivity at 100° C. of less than or equal to 1.0.10 ⁸ ohmmeters, preferably less than or equal to 5.0.10 ⁷ ohmmeters.

According to one embodiment, the grease composition according to the invention further comprises at least one complementary additive (that is to say different from the sulphonate additive), preferably chosen from antioxidant additives, anti-corrosion additives, antifoam additives and mixtures thereof.

Typically, when they are present, these additional functional additives represent (in total) from 0.1 to 25% by weight, preferably from 1 to 20% by weight, of the total weight of the grease composition.

These additives can be introduced separately and/or in the form of a mixture. The grease composition according to the invention may comprise at least one antioxidant additive. The antioxidant additive can be chosen from antioxidants of the phenolic or amine type.

The antioxidant additives may in particular be chosen from sterically hindered phenols, sterically hindered phenol esters and sterically hindered phenols comprising a thioether bridge, diphenylamines, diphenylamines substituted with at least one C1-C12 alkyl group, N,N '-dialkyl-aryl-diamines and mixtures thereof.

Amino compounds are another class of antioxidant additives that can be used, possibly in combination with phenolic antioxidant additives. Examples of amino compounds are aromatic amines, for example aromatic amines of formula NR ¹⁰ R ⁿ R ¹² in which R ¹⁰ represents an aliphatic group or an optionally substituted aromatic group, R ¹¹ represents an optionally substituted aromatic group, R ¹² represents a hydrogen atom, an alkyl group, an aryl group or a group of formula R ¹³ S(O) _Z R ¹⁴ in which R ¹³ represents an alkylene group or an alkenylene group, R ¹⁴ represents an alkyl group, a alkenyl group or an aryl group and z represents 0, 1 or 2.

The grease composition according to the invention may also comprise at least one antifoaming agent.

The antifoaming agent can be chosen from silicones.

The grease composition according to the invention may comprise from 0.01 to 2% by mass or from 0.01 to 5% by mass, preferably from 0.1 to 1.5% by mass or from 0.1 to 2% by mass of antifoaming agent, relative to the total weight of the composition.

The grease composition according to the invention can be prepared according to any method known to those skilled in the art for the preparation of grease. The sulphonate additive can be added to the mixture comprising at least one base oil and at least one thickener (mixture called “base grease”) by simple mixing, then the mixture thus obtained can be homogenized by grinding. The grease composition according to the invention can retain its performance in terms of electrical conductivity over time.

The invention also relates to a method for lubricating at least one component of an electric motor, preferably of an electric or hybrid vehicle, said method comprising bringing the component into contact with a grease according to the invention.

All of the characteristics and preferences presented for the grease according to the invention apply to the method of lubricating the component of an electric motor according to the invention.

The invention will now be described by means of the following examples, given of course by way of non-limiting illustration of the invention.

Examples

Example 1: Study of the addition of a sulfonate additive on electrical conductivity

The compositions described in Table 2 were prepared and tested.

The greases used in the examples are prepared as follows: a mixture of amines is reacted with a diisocyanate until a base grease comprising a mixture of diureas and base oil is obtained. The sulfonate additive is then added in different proportions and the fat composition is homogenized with a grinder.

The base grease (diureas and base oil) in Table 2 (CCI) has a resistivity at 100° C. of 1.19×10 ⁹ ohmmeter.

The sulphonate additive is a neutral salt of calcium dinonylnaphthalene sulphonate comprising approximately 2.1% by weight of calcium.

Table 2 indicates the proportions of the ingredients in percentage by weight relative to the total weight of the composition. [Table 2]

The electrical conductivity was measured at 50°C, 100°C and 150°C according to the following protocol: cleaning of the measuring body comprising a connector and a measuring sensor with: heptane and acetone drying with compressed air adding of 8 mL of grease composition with a syringe in the measurement sensor protection of the measurement sensor with a sheath for heating conductivity measurement at 50°C, 100°C and 150°C after measurement, cleaning with heptane and acetone .

Ohmmeter resistivity measurements are shown in Table 3.

[Table 3]

The results in Table 3 show that the addition of the sulphonate additive significantly reduces the resistivity, which is synonymous with an increase in the electrical conductivity. These results also show that conductivity is improved even at low treatment rates. Example 2: Other Sulfonate Additives

The additives described in Table 4 were tested.

[Table 4]

Grease compositions were prepared with the sulfonate additives in Table 4. Each grease composition includes 2% by weight sulfonate additive and 98% by weight base grease described in Example 1.

The resistivity measurements using an ohmmeter were carried out according to the protocol described in example 1 at 100° C. and are indicated in table 5.

[Table 5]

The results in Table 5 show that the resistivity is of the same order of magnitude with the various sulfonate additives tested.

Claims

1. Use of a sulfonate additive to increase the electrical conductivity of a grease composition comprising at least one base oil and at least one thickener.

2. Use according to claim 1, in which the thickener is chosen from fatty acid metal salts and polyureas, preferably from polyureas, more preferably from diureas.

3. Use according to claim 1 or 2, in which the sulphonate additive is chosen from metal sulphonate salts.

4. Use according to claim 3, in which the metal salt of the sulphonate is chosen from calcium salts, sodium salts, lithium salts, barium salts, magnesium salts, zinc salts, preferably from calcium salts, sodium salts, lithium salts, magnesium salts, zinc salts, more preferably from calcium salts, sodium salts, and advantageously from calcium salts.

5. Use according to any one of claims 1 to 4, in which the sulfonate additive is chosen from sulfonates comprising at least one aromatic group optionally substituted by one or more aliphatic groups.

6. Use according to any one of claims 1 to 5, in which the sulfonate additive is chosen from sulfonates comprising at least one naphthalene group optionally substituted by one or more aliphatic groups.

7. Use according to any one of claims 1 to 6, in which the sulfonate additive is chosen from alkylnaphthalene sulfonate, dialkylnaphthalene sulfonate, alkylnaphthalene sulfonate/carboxylate, dialkylnaphthalene sulfonate/carboxylate, the alkyl groups preferably being chosen from alkyl groups comprising from 1 to 24 carbon atoms, preferably from 3 to 18 carbon atoms, more preferably from 5 to 12 carbon atoms.

8. Use according to any one of claims 1 to 7, in which the sulfonate additive is added at a content ranging from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, relative to the total weight of the grease composition after addition of the sulfonate additive.

9. Grease composition comprising, relative to the total weight of the grease composition: from 70 to 95% by weight of base oil(s), from 4 to 20% by weight of thickener(s) chosen ) among the polyureas, from 0.1 to 10% by weight of sulfonate additive(s).

10. A grease composition according to claim 9, wherein the sulphonate additive is as defined in any one of claims 3 to 7.

11. Grease composition according to claim 9 or 10, having a resistivity at 100° C. of less than or equal to 1.0×10 ⁸ ohmmeters.

12. Grease composition according to any one of claims 9 to 11, comprising:

- from 75 to 90% by weight of base oil(s),

- from 5 to 15% by weight of thickener chosen from polyureas,

- from 0.5 to 5% by weight of sulphonate additive chosen from metal sulphonate salts comprising at least one naphthalene group substituted by one or more aliphatic groups, the salts being chosen from calcium salts, sodium salts, lithium salts, barium salts and magnesium salts.

13. Grease composition according to any one of claims 9 to 12, said composition comprising, relative to the total weight of the grease composition, less than 1% by weight of calcium 12-hydroxy stearate and less than 1% by weight stearate calcium, preferably less than 0.1% by weight calcium 12-hydroxy stearate and less than 0.1% by weight calcium stearate.

14. Grease composition according to any one of claims 9 to 13, characterized in that it is free of 12-hydroxy calcium stearate and free of calcium stearate.