FR2636958A1 - Chlorinated adhesion primer for a silicone elastomer - Google Patents

Abstract

Chlorinated adhesion primer for a silicone elastomer, comprising: - a chlorinated polyolefin, - an aminofunctional organosilicon compound containing a primary amine functional group, - an organic solvent. The primer according to the invention may additionally include an additive chosen from a UV absorber, a biocide chosen from a triorganotin oxide or halide and a substance which fluoresces in daylight. The primer according to the invention improves very particularly the adhesion of the silicone compositions employed to prevent the fouling of objects in contact with seawater or fresh water.

Description

CHLORINE ADHESION PRIMER FOR SILICONE ELASTOMER
The present invention relates to a chlorine adhesion primer for a silicone elastomer which can be used more particularly to improve the adhesion of silicone elastomers used to prevent fouling of the surfaces of various objects in contact with fresh water or water. sea.

A solution to prevent the fouling of surfaces of structures in contact with water, in particular sea water (ship hulls, fishing nets, drilling platforms, pipes, swimming pools, etc.) consists in covering these surfaces with a protective coating comprising at least one layer, the outer layer of the coating in contact with water being made of silicone elastomer.

There are many patents describing such coatings, the final layer of which is made of hot or cold cured silicone elastomer.

Thus FR-A-2,083,029 and US-A-3,702,778 teach that all the known categories of silicone can be used to produce an anti-fouling coating.

This base polymer may comprise along the chain, linked to certain silicon atoms, organic groups consisting of polymers grafted by polymerization of the corresponding monomer, in the presence of the organopolysiloxane; this monomer is preferably an ethylenic monomer (EP-A-32 957).

These silicone elastomers can also include fluids which improve the "antifouling" effect in particular.
- methylphenylpolysiloxane oils (US-A-4,025,693),
- a liquid hydrocarbon compound, for example a polyolefin, a plasticizer, a lubricating oil (FR-A-2 375 305),
- liquid paraffins and wax masses of the petrolatum type (KOKAI JP-A-83/013 673),
- a thermoplastic polymer such as PVC, a vinyl chloride / vinyl acetate copolymer (KOKAI JP-A-79/026 826),
- fluorescent substances (EP-A-63 388),
- cationic, anionic, nonionic, amphoteric surfactants (KOKAI JP-A-85/258 271).

These silicone elastomers are
- or applied to the surfaces to be protected. These surfaces can be of the most diverse materials such as metal, steel, aluminum and various metal alloys, plastics (PVC, polyester), wood, masonry, etc .....

- or applied to one or more sub-layers constituting the "antifouling" coating. These sublayers can be for example polyurethane, natural or synthetic rubber optionally chlorinated, such as chloroprene and neoprene, butyral rubber / silicone (KOKAI JP-A-78/137 231, JP-A-78/137 233 and JP-A-78/137 234).

One of the conditions necessary for the final silicone elastomer layer to have the longest possible service life is that this layer adheres as best as possible to its support.

Good adhesion is difficult to obtain during the deposition of the layer and is difficult to keep over time for the following reasons
- the silicone elastomers of the final layer can be of a very varied nature and contain many additives, some of which have a detrimental effect on adhesion,
- the surface to be coated, which can be either the surface to be protected, or the immediately lower layer of the "antifouling" coating can also be of extremely diverse nature,
- the immersion in water of the treated surfaces,
- the mechanical stresses imposed on the final layer either by displacement in the water of the treated surfaces, for example the hulls of ships, or by displacement of the water on the treated surfaces, for example the interior of a pipe of pure water.

Adhesion primers have already been proposed for the final “antifouling” layers of silicone elastomer.

Thus US-A-3,702,778 provides a solution of an organic silicate or of a crosslinkable silicone paste.

EP-A-89 066 proposes a primer formed either of a mixture of an epoxysilane and of a silane containing a hydrocarbon group with aliphatic unsaturation, or of a branched organopolysiloxane consisting of SiO2, (CH3) 3SiO0 5 and CH2 = units. CH (CH3) 2Si00.5.

Chlorinated polyolefins are known as well as their use in bulk or in solution in a solvent, as an adhesion primer in particular from US Pat. No. 3,561,965 and US Pat. No. 4,070,421.

When using chlorinated polyolefins as primer, it has already been proposed to combine various additives such as
- A chlorinated synthetic hydrocarbon resin such as a polyterpene resin and a. low molecular weight polystyrene resin (US-A-4,070,421),
- a vinyl resin (JP-A-83/015 535),
- an aromatic polyisocyanate, a silicone modified polyisocyanate and an optionally modified silicone diallylphthalate resin (JP-A-84/027 977),
- Chlorinated natural or synthetic rubbers are also known as adhesion primer (for example JP-A-78/081 537).

All these known primers are not entirely satisfactory for all the categories of elastomers that can be used and for the most common supports currently used, namely metals, in particular steel, aluminum, rigid PVC, and natural rubbers. or chlorinated synthetics.

An object of the present invention is precisely to provide an adhesion primer which gives suitable adhesion properties for most categories of silicone elastomers and for most of the substrates coated with these elastomers.

Another object of the present invention is furthermore to provide an adhesion primer which is effective for a long time even under the difficult conditions of “antifouling” coatings.

Another object of the present invention is to provide an adhesion primer which maintains and even improves the abrasion resistance of the final silicone elastomer layer.

dans laquelle
les radicaux R, identiques ou différents sont choisis parmi un radical hydrocarboné monovalent ayant de i à 12 atomes de carbone pouvant comporter une fonction éther,
R' est choisi parmi un radical alkyléne divalent, linéaire ou ramifié, ayant de 3 à 4 atomes de carbone, et un radical éther aliphatique divalent ayant de 3 à 8 atomes de carbone,
- R" est un radical monovalent choisi parmi un atome d'hydrogène et le radical -CH2CH2NH2, et x a une valeur moyenne comprise entre 2 et 3 inclus.These aims and others are achieved by the present invention which in fact relates to an adhesion primer for a silicone elastomer, characterized in that it comprises from (A) - 99 to 40% by weight of at least one organic solvent. and (B) - 1 to 60% by weight of
(I) - a chlorinated polyolefin,
(II) - from 0.1 to 50% by weight based on (I) of a compound
organosilicon carrying a primary amine
responding to the general average formula

in which
the radicals R, which are identical or different, are chosen from a monovalent hydrocarbon radical having from i to 12 carbon atoms which may contain an ether function,
R 'is chosen from a divalent linear or branched alkylene radical having from 3 to 4 carbon atoms, and a divalent aliphatic ether radical having from 3 to 8 carbon atoms,
- R "is a monovalent radical chosen from a hydrogen atom and the -CH2CH2NH2 radical, and x has an average value of between 2 and 3 inclusive.

Chlorinated polyolefins (I) are known products, available commercially. They are generally prepared by chlorination in a solvent medium of the starting polyolefins in the presence of a peroxide catalyst.

They generally have a molecular weight which may be between 5,000 and 50,000, a weight content of chlorine, calculated on the dry extract, generally between approximately 15 and 75 t, preferably between 17 and 40%.

The starting polyolefins are preferably poly olefins such as polyethylene, polypropylene. They can be high or low density, crystalline or amorphous.

These chlorinated polyolefins can contain also chlorinated hydrocarbon resins such as synthetic resins, polyterpenes and polystyrene resins.

These chlorinated polyolefins are for example described in detail in US patents US-A-3,561,965 and US-A-4,070,421 cited as reference.

The aminofunctional organosilicon compounds (II) of formula (1) are well known products, described in numerous documents such as, for example, FR-A-2 152 908.

In formula (1) of these organosilicon compounds (II), R is a hydrogen atom or a monovalent radical of 1 to 12 carbon atoms which may contain an ether function. The monovalent hydrocarbon radicals can be, for example, alkyl radicals (methyl, ethyl, hexyl, octyl), aryl (phenyl) or aralkyl (benzyl) radicals.

R 'is a divalent alkylene radical having 3 to 4 carbon atoms forming a divalent bridge between the silicon atom and the nitrogen atom; R 'can be trimethylene, tetramethylene, or trimethylene substituted with a methyl group.

R 'like R can also be a divalent aliphatic ether radical having from 3 to 8 carbon atoms such as for example - (CH2) 3-O- (CH2) 2-, - (CH2) 3-O- (CH2) 3- , -CH2-O- (CH2) 2-,
In formula (1), x has an average value between 2 and 3 inclusive.

As examples of compounds (I), mention may be made of the products of formulas
(CH30) 3Si (CH2) 3NH (CH2) 2NH2; (CH3CH2OCH2CH2O) 35i (CH2) 2NH2
(C2H5O) 3Si (CH2) 3NH2; (CH3OCH2CH2O) 3Si (CH2) 3NH2
(C2H50) 3Si (CH2) 30 (CH2) 3NH2; (C2H5O) 2C6H5Si (CH2) 30 (CH2) 3NH2
(C2H5O) 3SiCH2O (CH2) 2NH2; (C2H5O) 3Si (CH2) 3O (CH2) 2NH2
(C2H5O) 2CH3Si (CH2) 3NH2.

The content of (II) is 0.1 to 50% by weight based on the weight of (I), preferably 1 to 10% by weight are sufficient and effective.

dans laquelle
A est un radical hydrocarboné porteur d'un groupe époxy fonctionnel ayant de 4 à 12 atomes de carbone,
B, identiques ou différents, représentent un radical alkyle ayant de 1 à 4 atomes de carbone,
a est 0 ou 1.According to a preferred embodiment, it is possible to use instead of the silane (II), the same quantity by weight consisting of the reaction product (IV) of the silane (II) with a functional epoxy silane (III), of formula

in which
A is a hydrocarbon radical carrying a functional epoxy group having 4 to 12 carbon atoms,
B, identical or different, represent an alkyl radical having 1 to 4 carbon atoms,
a is 0 or 1.

The reaction of the silane (II) on the silane (III) can be carried out by following for example the teaching of European patents EP-A-178 751 and
EP-A-221 644 by simple mixing at 20-80 ° C., by reacting preferably, from 0.4 to 1.2 gram equivalent of primary amine function of silane (II) per gram equivalent of epoxy function of the silane ( III).

The preferred A radical is the glycidoxypropyl radical.

Specific examples of silanes (III) are as follows

Preferred adducts (IV) have the formulas

According to another preferred variant of the invention, it is possible to use instead of the silane (II), the same quantity by weight consisting of the reaction product (VI) of the silane (II) on an α, t-dihydroxyl) polydimethyliloxane oil. of formula (V)
HO {Si (CH3) 2O} yH in which y is an integer between 2 and 60 inclusive.

The reaction product (VI) can be obtained by simply mixing the silane (II) and the oil (v) at 20-80 Oc, preferably using 0.4 to 1.2 gram equivalent of alkoxy function ( OR) of silane (II) per gram equivalent of silanol function of the silane (V).

To the primer according to the invention, additives such as UV absorber compounds used in an amount of 0.1 to 20% by weight relative to (I) can be added, as well as compounds which are fluorescent in visible light and in UV rays.

UV absorber compounds are well known.

Mention may be made of benzotriazoles, benzophenones, cyanoacrylates and benzylidene malonates.

To the primer according to the invention, it is also possible to add, in the case of the "antifouling" application, a biocidal compound which is generally an oxide or a triorganotin halide such as, for example, tributyltin oxide or tribtyltin fluoride, thus than copper oxide.

The biocidal compound is used at a content of 0.01 to 5% by weight relative to the weight of (I).

In the primer according to the invention, the products (B) are dissolved in at least one suitable organic solvent (A).

The choice of the organic solvent is not critical since it serves only as a vector and a support for the primer in order to facilitate its application in a continuous and uniform layer on the surfaces of the substrate to be coated. This solvent must of course dissolve the products (B) without dissolving or attacking the surfaces to be protected.

Generally, a suitable solvent system is obtained by combining several organic solvents in varying proportions until the desired solubility characteristics are obtained.

Such solvent systems are well known in the art and need not be described in more detail.

The solvents which can be used are in particular optionally chlorinated aliphatic hydrocarbon solvents, optionally chlorinated aromatic solvents such as benzene, toluene and xylene; alcohols such as isopropanol, ethanol and butanol, monoalkyl ethers of ethylene glycol and propylene glycol, dialkyl ethers of ethylene glycol of ethylene glycol and of propylene glycol.

Aromatic solvents are the preferred solvents.

The primer according to the invention can also contain customary additives such as stabilizers, surfactants, antioxidants and thixotropic agents.

The primer is applied to the surface to be treated by known coating methods such as application by brush, roller, spraying and dipping.

After application of the primer, the layer is dried until the solvent is removed. The dried primer layer is then coated with a silicone-based composition crosslinking into an elastomer layer.

The primer according to the invention gives very efficient results, more particularly in the case where the surface to be treated is made of metal (steel, aluminum), PVC, polyolefin and chlorinated natural or synthetic rubber such as chlorobutyl rubber and even if this surface is in contact with fresh water or sea water.

The primer according to the invention gives good results for most silicone elastomers, and especially for those originating from the cold crosslinking of single-component, thixotropic organopolysiloxane compositions, flowing or diluted in an organic solvent, with acyloxy-, enoxy- crosslinking agents. , ketiminoxy-, alkoxy-, acetamido-, aminosilane and two-component compositions crosslinking by polycondensation or polyaddition reactions, the best results being obtained for ketiminoxy crosslinking agents.

Compositions of this type are for example described in US Pat. No. 4,525,565,
The following examples illustrate the invention. The parts and percentages indicated, unless otherwise indicated, are by weight.

- EXAMPLE 1
The primer P1 in accordance with the invention and, for comparison, the primers PC2, PC3 and PC4, outside the invention which have the following composition, are prepared by simple mixing
Composition according to the invention P1 - chlorinated polyolefin CP 512-28 at 40% in xylene, marketed by
EASTMAN KODAK Company * 25 parts
m - (B-aminoethyl) (y-aminopropyl) -trimethoxysilane 2 parts - xylene 73 parts
Control test: total absence of primer.

Comparative composition outside the invention PC1 - CP 512-2 25 parts - xylene 73 parts
Comparative composition outside the invention PC2 - CP 512-2 25 parts - (γ -glycidoxypropyl) trimethoxysilane 2 parts - xylene 73 parts *: having a chlorine content by weight calculated on the dry extract of
22% and a density of 1.1.

Comparative composition outside the invention PC3 - CP 512-2 25 parts - (N-morphol inopropyl) tr imethoxysi lane 2 parts - xylene 73 parts (N-morpholinopropyl) trimethoxysilane is an organofunctional silane containing a tertiary amine, the synthesis of which is described in US-A-4,672,003.

Cylindrical support specimens 8 mm in diameter and 10 mm in height are produced in aluminum (A), anodized aluminum (B),
Rigid PVC (C), chloroprene rubber type BUTACHLOR s (D), and polyurethane rubber (E).

These test pieces are coated with one of the following organopolysiloxane compositions El and E2
- E1: one-component thixotropic (non-flowing) organopolysiloxane composition with a ketiminoxysilane crosslinker catalyzed with tin and loaded with pyrogenation silica.

- E2: two-component organopolysiloxane composition hardening by polycondensation catalyzed with tin.

First of all, the test pieces of the different types of support tested are degreased beforehand with cyclohexane. After evaporation of the solvent, they are placed in lids of polyethylene powder compacts 95 mm in diameter and 15 mm in height. These lids serve as retention containers for flowable organopolysiloxane formulations. They allow easier storage as well as being able to easily reference the various tests.

The primer is spread over the surfaces to be coated with a stencil (cellulose wadding paper). The drying time is of the order of ten minutes.

The test pieces are then coated with the organopolysiloxane compositions El and E2.

The thickness of the coating is 2 millimeters.

The time required for good crosslinking was set at 120 hours, at ambient temperature and humidity.

The adhesion is assessed firstly in air at room temperature (test T1), by trying to take off the coating using a spatula, then by manually pulling on the films. crosslinked silicones.

Memberships were qualified in four ways
- good adhesion when peeling of the film is impossible (note 3),
- lack of adhesion when the film peels off very easily from a single piece (note O),
- slight adhesion when it is necessary to pull strongly enough on the film to obtain the film peeling (note 1),
- average adhesion when the peel is obtained with difficulty and by small surfaces (note 2).

- good adhesion when peeling is impossible (note 3j.

The test pieces which have given good results in the T1 test are subjected to a second T2 test consisting in immersing the test pieces in boiling water and in assessing, every hour for 8 hours, the adhesion which is evaluated according to the T1 test method. .

The results are collated in Table 1 below where the adhesion is noted from 0 to 3.

TABLE i

- xylène 73 parties l'adduct est le produit de réaction de ( > glycidoxypropyl)triméthoxysilane sur le (y-aminopropyl)triéthoxysilane conformément à l'enseignement des brevets européens EP-A-178 751 et EP-A-221 644.<tb><SEP> TEST <SEP> T1 <SEP> TEST <SEP> T2
<tb> PRIMARY <SEP> SUPPORT <SEP> E1 <SEP> E2 <SEP> El
<tb><SEP> (A) <SEP> 0 <SEP> 3
<tb><SEP> (B) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> P1 <SEP> (C) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (D) <SEP> 3 <SEP> 3 <SEP> 2 <SEP> after <SEP> 4 <SEP> hours
<tb><SEP> 0 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (E) <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (A) <SEP> 0 <SEP> 0
<tb><SEP> (B) <SEP> 0 <SEP> 0
<tb><SEP> WITNESS <SEP> (C) <SEP> o <SEP> o <SEP>
<tb><SEP> (D) <SEP> 1 <SEP> 0
<tb><SEP> (E) <SEP> 1 <SEP> 0
<tb><SEP> (A) <SEP> O <SEP> 0
<tb><SEP> (B) <SEP> O <SEP> 0
<tb><SEP> PC1 <SEP> (C) <SEP> 0 <SEP> 0
<tb><SEP> (D) <SEP> 0 <SEP> 0
<tb><SEP> (E) <SEP> O <SEP> 0
<tb><SEP> (A) <SEP> O <SEP> 0
<tb><SEP> (B) <SEP> O <SEP> 0
<tb><SEP> PC2 <SEP> (C) <SEP> 0 <SEP> 0
<tb><SEP> (D) <SEP> 0 <SEP> 0
<tb><SEP> (E) <SEP> O <SEP> 0
<tb><SEP> (A) <SEP> O <SEP> 0
<tb><SEP> (B) <SEP> O <SEP> 0
<tb><SEP> PC3 <SEP> (C) <SEP> 0 <SEP> 0
<tb><SEP> (D) <SEP> 0 <SEP> 0
<tb><SEP> (E) <SEP> O <SEP> 0
<tb> - EXAMPLE 2
The procedure of Example 1 is repeated exactly, except that the following primer compositions in accordance with the invention are used P2, P3 and P4
Primer P2 - CP 512-2s 25 parts - (y-aminopropyl) trimethoxysilane 2 parts - xylene 73 parts
Primary P3 - CP 512 - 2nd 25 parts - adduct of formula: 2 parts

- xylene 73 parts the adduct is the reaction product of (> glycidoxypropyl) trimethoxysilane on (y-aminopropyl) triethoxysilane in accordance with the teaching of European patents EP-A-178,751 and EP-A-221,644.

Primer P4 - CP 512-2s 25 parts - reaction product of one gram equivalent of 2-part methoxy function
of the functional amino silane used in PI on an equivalent
gram of silanol function of the oil of formula HO {Si (CH3) 20S5H - xylene - 73 parts
The results obtained from compositions P2 to P4 in tests T1 and T2 are collated in Table 2 below.

From Tables i and 2 it appears that the primers P1 to P4 according to the invention give particularly remarkable results on silicone elastomers containing ketiminoxy crosslinking.

Such results cannot be obtained without a primer, with only a chlorinated polyolefin (PC1), with only an epoxy functional silane (PC2) and with only a tertiary amine functional silane (PC3).

TABLE 2

<tb><SEP> Test <SEP> at <SEP> air <SEP> Immersion <SEP> at <SEP> 100 <SEP> C <SEP>
<tb><SEP> to <SEP> 20 <SEP> C <SEP> - <SEP> T1 <SEP> - <SEP> T2
<tb> PRIMARY <SEP> SUPPORT <SEP> El <SEP> E2 <SEP><SEP> El <SEP>
<tb><SEP> (A) <SEP> 0 <SEP> 3
<tb><SEP> (B) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> P1 <SEP> (C) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (D) <SEP> 3 <SEP> 3 <SEP> 2 <SEP> after <SEP> 4 <SEP> hours
<tb><SEP> 0 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (E) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (A) <SEP> 2 <SEP> 3
<tb><SEP> (B) <SEP> 3 <SEP> 3 <SEP> O <SEP> after <SEP> 1 <SEP> hour
<tb><SEP> P2 <SEP> (C) <SEP> 3 <SEP> 3 <SEP> 2 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (D) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (E) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (A) <SEP> 3 <SEP> 2 <SEP> 2 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (B) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> P3 <SEP> (c) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (D) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (E) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (A) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (B) <SEP> 3 <SEP> 3 <SEP> 2 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> P4 <SEP> (c) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb><SEP> (D) <SEP> 3 <SEP> 3 <SEP> O <SEP> after <SEP> 6 <SEP> hours
<tb><SEP> (E) <SEP> 3 <SEP> 3 <SEP> 3 <SEP> after <SEP> 8 <SEP> hours
<tb>

Claims (6)

1. - Primer for silicone elastomer, characterized in that it comprises (A) - 99 to 40 t by weight of at least one organic solvent and (B) - 1 to 60 t by weight of (I) - a chlorinated polyolefin, (II) - from 0.1 to 50 t by weight based on (I) of a compound organosilicon carrying a primary amine responding to the general average formula:

in which the radicals R, which are identical or different, are chosen from a monovalent hydrocarbon radical having from 1 to 12 carbon atoms which may contain an ether function, R 'is chosen from a divalent alkylene radical having from 3 to 4 carbon atoms and a divalent aliphatic ether radical having from 3 to 8 carbon atoms, - R "is a monovalent radical chosen from a hydrogen atom and the -CH2CH2NH2 radical, and x has an average value of between 2 and 3 inclusive. 2. - Primer according to claim 1, characterized in that the organic solvent is chosen from aromatic organic solvents. (C2H5O) 2CH3Si (CH2) 3NH2. (C2H5O) 3SiCH2O (CH2) 2NH2; (C2H5O) 3Si (CH2) 3O (CH2) 2NH2; (C2H50) 3Si (CH2) 30 (CH2) 3NH2; (C2H50) 2c6H5Si (CH2) 30 (CH2) 3NH2 (C2H5O) 3Si (CH2) 3NH2; (CH3OCH2CH2O) 3Si (CH2) 3NH2; (CH30) 3Si (CH2) 3NH (CH2) 2NH2; (CH3CH2OCH2CH2O) 3Si (CH2) 2NH2; 3. - Primer according to claim 1 or 2, characterized in that the silane (it) is chosen from those of formulas 4. - Primer according to any one of the preceding claims, characterized in that the chlorinated polyolefin (I) has a molecular weight of between 5,000 and 50,000 and a weight content of chlorine between 15 and 75 t 5. - Primer according to any one of the preceding claims, characterized in that it further comprises at least one of the following additives - from 0.1 to 20 t by weight relative to (I) of compounds which fluoresce in visible light and in U.V., - from 0.1 to 20% by weight relative to (I) of W absorbing compounds, - From 0.01 to 5% by weight relative to (I) of a biocide. 6. - A primer for a silicone elastomer as defined in any one of claims 1 to 5, used for producing an “anti-fouling” coating.