FR2633947A1 - Composition and process for the anticorrosion treatment of mechanical components based on ferrous alloys - Google Patents

Abstract

Composition capable of producing, by fast drying, a translucent film for the anticorrosion treatment of mechanical components based on ferrous alloys and, more particularly, of wrought components such as motor vehicle transmissions, characterised in that it comprises: - at least one calcium salt of oxidised petrolatum, - at least one overbased calcium sulphonate of formula: [R(SO3)b]2Cab,(CaCO3)a in which: . R is an alkylaryl group, . a, which is a positive number such that 1 < a </= 3, denotes the equivalent excess of basic salt in relation to stoichiometry, and . b is such that 1 </= b </= 5, the weight ratio of the calcium salt of oxidized petrolatum to the overbased calcium sulphonate being between 1 and 9 and preferably between 3.5 and 5.5. - at least one petroleum solvent, and - at least one antirust additive. b

Description

Composition and method for anticorrosion treatment
of mechanical parts based on iron alloys
The subject of the invention is a composition and a process for the anti-corrosion treatment of mechanical parts based on iron alloys and, more particularly, of engineered parts such as motor vehicle transmissions.

 Automotive transmissions are made up of steel components and include, in particular, a central tube and cardan shafts, the latter being protected by bellows, in particular made of polymer synthetic material.

 The corrosion protection which is given to the transmissions in question before they are fitted to the vehicle to be fitted with them must correspond to the anti-corrosion guarantees granted by the manufacturer to the user.

 However, the protection provided by the products used for this purpose to date does not correspond to these guarantees since the resistance to corrosion according to the salt spray test (standard NF X 41002) of the treated parts is less than 48 hours, whereas, according to current requirements, it must be at least 125 hours.

 On the other hand, the aforesaid known products which essentially comprise mixtures of bituminous pitches and solvents, forge black and opaque protective films forcing the provision of a saving of protection so as not to mask the identification markers in color of the itodel of transmission manufactured; protection is therefore zero.

 The object of the invention is, above all, to remedy the drawbacks and inadequacies of the prior art and to provide a composition and a method for the anticorrosion treatment of mechanical parts based on iron alloys, more particularly, of worked parts such motor vehicle transmissions capable of conferring on the treated parts an anticorrosion protection meeting the current industrial requirements.

The composition according to the invention which is suitable for rapidly translating translucent film 9, is characterized in that it comprises: - at least one calcium salt of petrolatum oxide, - at least one overbased calcium sulfonate of formula
(R (S03) b) 2 Cab, (CaCO3> a
in which
R Rest an alkylaryl group,
a, which is a positive number such that 1 <a <3,
represents the equivalent excess of basic salt by
compared to stoichiometry, and
b best such that 1 <b C 5,
the weight ratio between the calcium salt of petrolatum
oxidized and overbased calcium sulfonate being included
between 1 and 9 and preferably between 3.5 and 5.5, - at least one petroleum solvent consisting of a cut pe
aliphatic trolière containing less than 5% of aromatics
and whose distillation interval is between 60
and 2200C, preferably between 90 and 1500C and extends more
preferably still from 100 to 130in, - at least one anti-rust additive chosen from the group
including:
alkaline earth metal sulfonates, other than
calcium,
fatty amines,
the salts of fatty amines of carboxylic acids,
alkylsarcosinate derivatives,
imidazoline derivatives.

 The calcium salt of oxidized petrolatum can be obtained by neutralization with lime and preferably about 800C of an oxidate consisting of a mixture of carboxylic acids, alcohols, esters, lactones and ketones and resulting from hot catalytic oxidation of a mixture of alkanes.

 The above mixture of alkanes can be a mixture of n- and iso-alkanes, the carbon chains of which comprise between 35 and 80 carbon atoms; the oxidate obtained from this mixture has an acid number of 40 60 and a saponification number of 80 d 150.

The aforesaid calcium salt of oxidized petrolatum obtained by neutralization of the oxidate has a melting point greater than or equal to 800C and a coloring according to the method
ASTM D 1500 less than 7.

As the calcium salt of oxidized petrolatum, the product sold by the company EXXON can be used.
CHEMICAL under the brand HYPAX 450-18-50 LL. This product has the following features:
a melting point (of the dry product) between 115
and 1300C,
a coloration of 2.0 according to the ASTM D 1500 method,
a content of calcium oxides between 48 and
52%.

 The above overbased calcium sulfonates result from the reaction of carbon dioxide on the excess lime used to make the reaction in a solvent medium between a sulfonic acid and calcium hydroxide.

 The preparation of these sulfonates is described in U.S. Patent No. 3,453,124.

 As examples of overbased calcium sulfonates, those which are marketed under the brand SACI 300 by the company WITCO and under the brands CCI base 30 and CCI base 40 by the company KIMES can be used; SACI 300 is preferred; in addition to the overbased calcium sulfonate, it contains a wax.

The SACI 300 has the following characteristics:
density A 20 * C: 0.96
organic mineral complex content: 32%
non-volatile matter content: 62%
flash point: 40vu.

Advantageously, the above composition in accordance with the invention comprises an effective amount of at least one of the additives from the group comprising
resistivity additives,
waxes of natural or synthetic origin,
developers sensitive to light radiation.

The above petroleum solvent is used in an amount chosen so that a quick-drying wet film is obtained on the part to be treated and that, in particular, drying of the product is avoided directly at the gun outlet in the event of 'application with such material to prevent the formation of filaments; in practice, this amount is between 20 and 85% and, preferably,
- between 40 and 85% in the case of a liquid protective composition used at room temperature,
- between 20 and 60% in the case of a protective composition applied after liquefaction by an appropriate heating system.

 By way of example, it is indicated that a product which may be suitable consists of the solvent called "essence E" and marketed by many companies.

 The anti-rust additives which form part of the composition in accordance with the invention make it possible to improve the resistance performance thereof in the salt spray test according to standard NF X 41002.

As an example of an anti-rust additive, a fatty diamine dioleate sold by the
CECA company under the INIPOL 002 brand.

 The wax which can enter into the composition of the composition in accordance with the invention is advantageously a wax of natural or synthetic origin making it possible to modify the nature of the film obtained.

 The revealing additive sensitive to light radiation, that is to say capable of highlighting the coating, can be constituted by a solution of fluorescein or more generally by a compound with an aromatic nucleus when the development is carried out using 'a beam of ultra-violet light or by a conventional dye when the revelation is carried out using a beam of natural light.

 The composition according to the invention may also contain at least one viscosity adjuvant.

By way of example, the composition in accordance with the invention can be made up as follows: - from 16 to 20 parts by weight of petro calcium salt
oxidized latum, - from 3.6 to 4.6 parts by weight of calcium sulfonate
overbased, - from 0.2 to 0.6 parts by weight of anti-rust additive - from 3.5 to 4.5 parts by weight of natural or syn wax
cosmetic, - approximately 0.5 parts by weight of developer sensitive to
light radiation, - a petroleum solvent in qs 100 parts by weight.

More particularly, the constitution of the above composition can be as follows: - from 32 to 40 parts by weight of HYPAX 450-18-50 LL - from 11.3 to 14.3 parts by weight of SACI 300 - from 0, 2 to 0.6 parts by weight of INIPOL 002 - approximately 0.5 parts by weight of alcoholic solution of
0.025% fluorescein - a petroleum solvent in qs 100 parts by weight.

 The process according to the invention is characterized in that an effective amount of the composition according to the invention is applied to the mechanical parts to be treated and the part thus treated is dried.

 The application of the composition according to the invention can be manual.

One can also have recourse, for applying said composition, to an installation comprising for example:
- an application device equipped with either ramps
spray gun with pneumatic guns
or centrifugal spraying systems,
all of these elements being oriented to treat
correctly and entirely the part and in particular the
transmission,
- a ventilated area, the temperature of which can be left
ambient and in which the passage time,
adjustable, around 10 minutes,
- a stall and manual conditioning area
rooms, located at the exit of the ventilated area,
parts processed, when it comes to elements of
elongated transmission, capable of being
gripped by their central tube without the coating
protector be altered,
means for cleaning the supports of the
parts conveyed using a solvent, used even
in vapor phase.

 The effective quantity of composition used in the process according to the invention is that which makes it possible to obtain on the treated part a continuous film with a thickness of 20 to 100 micrometers.

 The composition according to the invention has many advantages.

 It makes it possible to form a film which dries quickly without adding heat energy to the drying and therefore avoids investment in equipment, the standard equipment always available at the places of application being usable; the protective coating of the treated parts and more particularly of the transmissions is in fact completely dry and can be handled approximately 10 minutes after the application of the composition.

 By way of illustration, it is pointed out that the drying in a ventilated unheated zone of pieces coated with a composition according to the prior art (which are usually always dried in a ventilated zone whose non-adjustable temperature is approximately 60vu) leads, after 10 minutes of ventilation, either to a non-dry coating that cannot be handled, or to an unsightly coating, brittle and formed of unevenly distributed tangled wires.

 On the contrary, the parts treated in accordance with the invention offer, after the same drying, a waxy, regular, smooth, dry external appearance, from transparent to translucent.

 However, even in the case of manual application, for example with a brush, the use of the composition according to the invention is advantageous because, even if the energy gain is zero since the parts can be stored while waiting for air drying, storage space is saved due to rapid drying.

Other advantages inherent in the invention lie in the fact that - the composition applied does not modify the characteristics
physical ticks of the polymeric materials making up
protective bellows for cardan joints, - the composition is applicable to any model of
transmission, in particular
on steel transmissions with residue
greasy, due to the use of a lubricating oil for
the fitting of the rubber bellows,
on dry transmissions having previously undergone
an alkaline wash and possibly a treatment of
carbo-nitriding, - the film formed after drying of the composition
retains its properties even after being brought to
temperatures close to 150-C corresponding to the tempé
extreme erasures encountered when using
motor vehicles, - the translucent formed film does not hide the marks
colored identification of each transmitted model
sion, these marks being put in place before application
of the product; moreover, this film can be inco
lore, it may be beneficial to make the
starting composition an additive detectable by light
to identify any untreated areas, - the composition which makes it possible to obtain a film with
quick drying and dry touch, is enough
"wet" on application to dissolve oils
residual lubricants and lead 9 grip
correct, the final coating being homogeneous, - the composition is chemically compatible with
additives commonly used in motor oils, - the film obtained after drying has a capacity
sufficient lubricant to eventually allow
the fitting of the transmission on the outlet of the
gearbox and - the composition is easily removable from the "balan
those "used to transport the parts and which are
soiled using a chlorinated solvent in phase
steam.

 The invention can be clearly understood with the aid of the following nonlimiting examples which demonstrate that a composition according to the invention meets the requirements set by the user.

EXAMPLE 1
Composition used: - HYPAX 450-18-50 LL 36.5 parts - SACI 300 12.1 parts - INIPOL 002 0.4 parts - 0.025% alcoholic solution
0.5 part fluorescein - essence E 50.5 parts.

 The product obtained appears as a homogeneous light beige dispersion, with a density equal to 0.79, with a viscosity of 50 seconds according to AFNOR T 30014 standard (section having an orifice diameter of 2.5 mm).

 The weight ratio between calcium oxidate and calcium sulfonate is 4.7.

 The composition is applied industrially to a series of transmissions comprising fatty residues due to the use of a lubricant product constituted by INTEC AR 175 sold by the Applicant Company and which comprises oil, this product being necessary for the fitting of the cardan protection bellows.

 The application is made in an installation of the type described above, after adjusting the operating parameters of the sprayers (flow rate, air pressure, rotation speed of the minibols).

 A wet film is deposited on the parts to be treated, making it possible to achieve a dry film thickness of between 40 and 50 micrometers.

 After 10 minutes of drying in a ventilated oven at a temperature of 20 μl, it is observed that the treated transmissions can be handled without altering the coating.

The latter has a dry and homogeneous appearance.

 The film is sufficiently translucent to allow the identification marks of the transmission model to be seen through.

 No modification (appearance, swelling) of the polymer bellows is observed.

 It is also noted that the product deposited on the "swings" is completely eliminated after passing through the degreasing installation.

 Three transmissions are sampled for resistance to salt spray test according to standard NF X 41002.

 After 150 hours, it is noted that all the parts have a corrosion rate of less than 10% of the surface to be protected, which is the objective to be achieved.

EXAMPLE 2
It is a comparative example.

A test similar to that described in Example 1 is carried out using a "reference 129" pitch paint sold by the manufacturer as protection product.
SPLM Company; it is the product usually used for the anti-corrosion protection treatment of transmissions.

 To dry this paint, it is necessary to raise the temperature of the ventilated oven to 60il.

 The film obtained is black and hides the identification marks.

 Three pieces taken and subjected to a salt spray resistance test according to standard NF X 41002 show that the percentage of corroded surface is greater than 10% after only 48 hours of testing.

 This example shows that the product used to date cannot meet the objectives set.

EXAMPLE 3
The composition of Example 1 is applied to transmissions previously washed with an alkaline degreaser such as that which is marketed under the brand.
PROGAL G 183 DR by the Applicant Company, then these transmissions are passed through a carbo-nitriding oven.

We note as in Example 1:
that the coating does not hide the identi
fication,
that the film is homogeneous, adherent and that it
has a dry and handy appearance after 10 minutes
drying in a ventilated oven at 20-C,
that the rubber bellows have the same hardness,
they do not show swelling or change
appearance cation.

 Three transmissions are taken for the salt spray test according to standard NF X 41002.

 After 150 hours of exposure, a corrosion rate lower than 10% is noted, which is the objective to be achieved.

EXAMPLE 4
An application of the composition according to Example 1 is carried out in the laboratory on cold-rolled steel plates of dimension 100 × 150 mm using a spraying device.

 We make sure that the thickness of the dry film deposited is 40 to 50 micrometers.

 The platelets thus treated are placed vertically in an oven brought to isois for 2 hours.

 It is noted, after baking, that the applied composition has no sagging and that the anticorrosion performance of the coating is identical before and after baking.

EXAMPLE 5
Transmission parts are treated according to Examples 1 and 3, one of the pneumatic guns having been eliminated to simulate an industrial breakdown.

 Observation under an ultraviolet lamp highlights the parts where the coating has not been correctly applied, thus making quality control possible.

EXAMPLE 6
This example concerns dynamic tests on the resistance of coatings.

 The composition according to Example 1 is applied to a transmission (thickness of the dry film = 30-40 micrometers).

 The temperature of the transmission thus coated is brought to 90iC (at the rate of temperature rise of 1 degree per min).

 At 90 ° C., the transmission is rotated for 45 min at 1000 rpm ,. which is equivalent to a speed of 120 km / h.

 Several times in succession, the rotation is stopped, the temperature is increased by 100C each time and the transmission is rotated again under the same conditions.

 The composition according to the invention has very good resistance to dynamic testing up to 130 ° C., maximum temperature reached in the test system: there is no visible change in the protective film.

Claims (11)

 1. Composition suitable for leading, by rapid drying, to a translucent film for the anticorrosion treatment of mechanical parts based on iron alloys and, more particularly, of engineered parts such as transmissions of motor vehicles, characterized in that it includes: - at least one calcium salt of oxidized petrolatum, - at least one overbased calcium sulfonate of formula  (R (S03) b] 2 Cab, (CaC03) a  in which  R Rest an alkylaryl group,  a, which is a positive number such that 1 <a C 3,  represents the equivalent excess of basic salt by  compared to stoichiometry, and  b best such as 1 C b C 5,  the weight ratio between the calcium salt of petrolatum  oxidized and overbased calcium sulfonate being included  between 1 and 9 and preferably between 3.5 and 5.5, - at least one petroleum solvent consisting of a cut pe  aliphatic trolière containing less than 5% of aromatics  and whose distillation interval is between 60  and 220 C, preferably between 90 and 1500C and extends more  preferably still from 100 to 130C, - at least one anti-rust additive chosen from the group  including:  alkaline earth metal sulfonates, other than  calcium,  fatty amines,  . the salts of fatty amines of carboxylic acids,  . alkylsarcosinate derivatives,  . imidazoline derivatives.  2. Composition according to claim 1, characterized in that it comprises a resistivity additive.  3. Composition according to one of claims 1 and 2, characterized in that it comprises a wax of natural or synthetic origin.  4. Composition according to one of claims 1 to 3, characterized in that it comprises at least one developer sensitive to light radiation.  5. Composition according to one of claims 1 to 4, characterized in that the amount of petroleum solvent is between 20 and 85% and preferably  - between 40 and 85% in the case of a liquid protective composition used at room temperature,  - between 20 and 60% in the case of a protective composition applied after liquefaction by an appropriate heating system.  6. Composition according to one of claims 1 to 5, characterized in that it comprises: - from 16 to 20 parts. By weight of petro calcium salt  oxidized latum, - from 3.6 to 4.6 parts by weight of calcium sulfonate  overbased, - from 0.2 to 0.6 parts by weight of anti-rust additive - from 3.5 to 4.5 parts by weight of natural or syn wax  cosmetic, - approximately 0.5 parts by weight of developer sensitive to  light radiation, - a petroleum solvent in q.s.p. 100 parts by weight.  7. Composition according to claim 6, characterized in that it comprises: - from 32 to 40 parts by weight of HYPAX 450-18-50 LL - from 11.3 to 14.3 parts by weight of SACI 300 - from 0.2 to 0.6 part by weight of INIPOL 002 - approximately 0.5 part by weight of alcoholic solution  0.025% fluorescein - a petroleum solvent q.s.p. 100 parts by weight.  8. Method for the anticorrosion treatment of mechanical parts based on iron alloys and, more particularly, engineered parts such as transmissions of motor vehicles, characterized in that an effective amount is applied to the mechanical parts to be treated of the composition according to one of claims 1 to 7 and that the treated part is dried.  9. Method according to claim 8, characterized in that the application of the composition according to one of claims 1 to 10 is carried out manually.  10. Method according to claim 8, characterized in that the application of the composition according to one of claims 1 to 7 is carried out using an installation comprising:  - a team or ramp application device  spray gun with pneumatic guns  or centrifugal spraying systems,  all of these elements being oriented to treat  correctly and entirely the part and in particular the  transmission,  - a ventilated area, the temperature of which can be left  ambient and in which the passage time,  adjustable, around 10 minutes,  - a stall and manual conditioning area  rooms, located at the exit of the ventilated area,  parts processed, when it comes to elements of  elongated transmission, capable of being  gripped by their central tube without the coating  protector be altered,  means for cleaning the supports of the  parts conveyed using a solvent, used even  in vapor phase.  11. Method according to one of claims 8 to 10, characterized in that the quantity of composition used is chosen so that it allows to obtain on the treated part a continuous film with a thickness of 20 at 100 micrometers.