Organic titanate as adhesion promoter for anti-noise pads to brake pads, related brake pads and methods

Abstract

In order to promote the adhesion of the anti-noise gasket (6) to a surface (7) of a metal support (2) of the brake element (1), which surface (7) is normally coated with epoxy resin, by gluing the anti-noise gasket (6) to the surface by means of an acrylic adhesive, the surface (7) is pretreated by applying a primer to an epoxy resin paint layer (9), the primer comprises an organic titanate (10) diluted in an organic solvent, preferably an alcoholic polar solvent; the organic titanate (10) is preferably a tetraalkoxytitanium (IV) represented by the general formula Ti (OR) 4.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Italian Patent Application No. 102022000012896 filed on June 17, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to the use of a specially selected primer compound for promoting adhesion between an anti-noise sheet element, known as a "shim", and a first face of a metal support carrying a block of friction material or a lining on its second face opposite to the first face, the metal support together with the block of friction material and the shim forming a vehicle brake element, such as a brake shoe or brake pad, in particular a brake pad.

[0004] The invention also relates to a related method for anchoring a covering flat element, in particular an anti-noise sheet element or a gasket, to a metal surface of a support in a secure and substantially permanent manner, in particular when the metal surface is coated with an organic resin, such as an epoxy resin.

[0005] The invention further relates to a brake element for a vehicle in question provided with an anti-noise element or shim having improved adhesion. Background Art

[0006] Braking elements commonly used in modern vehicles include a brake pad comprising a block of friction material and a support thereof comprising a metal plate defined by first and second opposing faces.

[0007] The first face is usually provided with a sheet element or foil called a "shim" which covers most or all of the first face, while the second face carries a block of friction material bonded thereto, for example by gluing or other methods.

[0008] In use, a direct or indirect thrust is applied to the first face to press the block of friction material carried by the second face towards the element to be braked, such as a vehicle brake disc.

[0009] Since during this operation noise and vibrations may be generated due to the thrust applied to the metal surface of the first face of the support (also called "back plate"), the first face is provided with an anti-noise element called a gasket, which is designed with elastic properties to absorb or at least reduce such noise and vibrations.

[0010] There therefore exists the problem of ensuring that the anti-noise spacer is securely attached to the first face of the support to avoid accidental detachment in use.

[0011] Unfortunately, brake pads today (both the friction material block and the metal backing plate) are coated with a protective paint, typically epoxy, so that anchoring the pad to the coated (painted) metal surface of the backing plate in a secure manner can be problematic.

[0012] Typically, an anti-noise gasket, which is usually applied to the backing plate, is bonded to the backing plate using acrylic resin as an adhesive.

[0013] However, also due to the presence of the epoxy coating, the adhesion between the gasket and the epoxy-coated backing plate may be low, with the risk of subsequent separation during use of the gasket due to the mechanical stresses to which the gasket is typically subjected.

[0014] In fact, the reduced presence of polar groups on the metal support surface makes its surface tension low and therefore the ability of the anti-noise gasket acrylic adhesive to adhere to it is also low. The low interaction between the metal surface and the adhesive leads to an easy separation of the anti-noise element (gasket) from the backing plate.

[0015] To solve this problem, a combustion treatment has hitherto been used for the surface designed to receive the anti-noise pad. In fact, this treatment is known to polarize the surface by forming functional groups such as -OH, -COOH.

[0016] However, this treatment is preferably avoided because, in some cases, it is not very effective (so it does not address the risk of gasket separation) and is dangerous, cumbersome and expensive to perform.

[0017] In order to avoid the aforementioned disadvantages, the back plate may be provided with mechanical attachment points for the anti-noise gasket, as schematically shown in FIG. 1 .

[0018] The back plate A is provided with a pin P on its metal surface S facing the gasket SH, said pin P being provided integrally with the back plate A and arranged in a shallow recess R formed on the metal surface S. The gasket SH is also provided with a hollow boss B to which the pin P is mechanically coupled.

[0019] However, it is apparent that such a solution is complex and expensive to implement. Summary of the invention

[0020] An object of the present invention is to provide a method for anchoring a cover sheet element, such as an anti-noise shim, to the surface of a metal support of a brake element, such as the back plate of a vehicle brake pad, which method does not have the disadvantages of the prior art and in particular is reliable, easy and inexpensive to implement.

[0021] Another object of the invention is to provide a brake element, in particular a brake pad, comprising a support for a block of friction material and an anti-noise shim applied to the support on the side opposite to the block of friction material, wherein the shim is joined to the support in a strong and simple manner.

[0022] Thus, according to the present invention, a method for anchoring a covering sheet element, such as an anti-noise shim, to the surface of a metal support of a brake element, such as a back plate of a vehicle brake pad, and a related brake element are provided as defined in the appended claims.

[0023] The invention also relates to the use of specially selected chemical compounds as primers for promoting chemical adhesion of cover sheet elements such as anti-noise pads to the metal surface of a support, in particular to the metal backing plate of a brake pad, opposite its friction material block.

[0024] According to an embodiment of the present invention, the covering sheet element preferably comprises an anti-noise gasket of any type known in the art anchored / bonded to the surface of a metal support (e.g. a back plate) of a brake element by the following method: the method comprises gluing the covering sheet element to such a surface and a step of pre-treating the surface before the gluing step, wherein the step of pre-treating the surface comprises applying a primer compound thereto, the primer compound comprising an organic titanate diluted in an organic solvent.

[0025] In a preferred embodiment, the organic titanate is a tetraalkoxytitanium (IV) represented by the general formula:

[0026] [1]Ti(OR) 4 ,

[0027] Wherein all R are the same or different and can be selected from: unsubstituted single-chain or branched alkyl groups (alchilic group); substituted single-chain or branched alkyl groups, wherein the substituents are selected from: amino groups, phosphilic groups, ether groups, and unsaturated hydrocarbon groups.

[0028] In a preferred embodiment, the organic solvent is an alcoholic polar solvent.

[0029] The alcohol polar solvent may be selected from isopropanol, ethanol, acetone, and mixtures thereof.

[0030] In the most preferred embodiment, the alcoholic polar solvent is isopropanol.

[0031] In an embodiment of the method of the present disclosure, the following steps are performed on a surface of a metal support designed to receive a cover sheet element, i.e. an anti-noise gasket:

[0032] a) painting the surface with epoxy resin;

[0033] b) applying an organic titanate in an organic solvent onto such a surface already coated with epoxy resin to form a uniform layer of the organic titanate in solution on the surface and on top of the epoxy resin;

[0034] c) Gluing the cover sheet element to the already painted surface pretreated with the organic titanate diluted in an organic solvent by applying an acrylic glue or an adhesive based on acrylic resin between the cover sheet element and the uniform layer of the organic titanate in solution.

[0035] In a preferred embodiment, the cover sheet element comprises an anti-noise shim and the metal support comprises a back plate of a vehicle brake pad, the aforementioned surface defining a first face of the back plate opposite its second face carrying a block of friction material.

[0036] In a preferred embodiment, the organotitanate is diluted in an alcoholic polar solvent at a dilution of 0.5% v / v to 5% v / v (volume to volume).

[0037] In a preferred embodiment, an organic titanate diluted in an organic solvent is applied to the aforementioned surface using a technique selected from the following:

[0038] - by spraying organic titanate solution,

[0039] - with the aid of a roller coated with a solution of an organic titanate,

[0040] - By dropping the organotitanate solution unevenly onto the surface and then distributing it evenly with a cloth or a cloth-covered applicator such as a rotating disk.

[0041] An embodiment of the invention comprises a brake element, in particular a brake pad, comprising a support for a block of friction material and an anti-noise shim applied to the support on a side opposite to the block of friction material, wherein the shim is bonded to a first face of the support opposite to the block of friction material, wherein:

[0042] i) - The first side of the support is coated with a first layer of epoxy resin;

[0043] ii) a second layer of organic titanate is spread on the first layer of epoxy resin, the organic titanate comprising alkoxy groups;

[0044] iii) - the gasket is bonded to the first face by means of a third layer of acrylic resin located on the second layer of organic titanate;

[0045] iv) - wherein at least a portion of the corresponding alkoxy groups have been hydrolyzed by both the acrylic resin and the epoxy resin, thereby forming a chemical bond between the first layer and the third layer.

[0046] In a preferred embodiment of the brake element according to the invention, the organic titanate forming the second layer is a member of the general formula Ti(OR): 4 Tetraalkoxytitanium (IV) represented by wherein R are all the same or different and are preferably selected from: unsubstituted single-chain or branched alkyl groups; substituted single-chain or branched alkyl groups, wherein the substituents are selected from: amino groups, phosphoric acid groups, ether groups, unsaturated hydrocarbon groups.

[0047] Embodiments of the present invention include the use of a primer compound for promoting adhesion of an anti-noise sheet element or shim to the surface of a metal support of a brake element, in particular a backing plate of a vehicle brake pad, wherein:

[0048] - said surface is coated with epoxy resin,

[0049] - the anti-noise gasket is glued to the surface by means of acrylic glue or an acrylic resin-based adhesive,

[0050] - spreading the primer compound over the epoxy paint covering the surface so as to be placed between the epoxy and the acrylic glue or adhesive,

[0051] - the primer compound comprises an organic titanate diluted in an organic solvent, preferably an alcoholic polar solvent,

[0052] -Organo titanate is composed of the general formula Ti(OR) 4 Tetraalkoxytitanium (IV) represented by wherein R are all the same or different and are preferably selected from: unsubstituted single-chain or branched alkyl groups; substituted single-chain or branched alkyl groups, wherein the substituents are selected from: amino groups, phosphoric acid groups, ether groups, unsaturated hydrocarbon groups.

[0053] In a preferred embodiment of the use according to the invention, the organic titanate is diluted in an alcoholic polar solvent at a dilution of 0.5% v / v to 5% v / v, then applied to the painted surface of the metal support and left to dry at room temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Preferred but non-limiting embodiments of the invention will now be described in more detail with reference to a number of actual working examples of its implementation and with reference to the figures in the accompanying drawings, which are intended only to disclose in a non-exhaustive and non-limiting manner the features that are part of the content of the present disclosure, in which:

[0055] - FIG. 1 shows in a schematic manner a prior art solution for ensuring a mechanical connection between an anti-noise shim and a corresponding mating surface of a back plate of a brake pad, without showing the entire brake pad for the sake of simplicity;

[0056] - Figure 2shows, on an enlarged scale, a schematic cross-sectional view of a metal support of a brake pad manufactured according to the invention and provided with an anti-noise shim bonded to the support by the method according to the invention;

[0057] - Figure 3 and Figure 4 The execution of two different tests for checking the effectiveness of the bond between a metal support and a known anti-noise gasket is shown in a schematic manner;

[0058] - Figure 5 and Figure 6 A plan view and a cross-sectional view taken along section VI-VI respectively show a brake element according to the present invention, namely a brake pad; and

[0059] - Figure 7 A simplified block diagram illustrating a sequence of steps of the method of the present invention is shown. DETAILED DESCRIPTION

[0060] Reference Figure 2 , Figure 5 , Figure 6 and Figure 7 , reference numeral 1 is generally ( Figure 5 ) represents a brake element for a vehicle, which in the non-limiting embodiment shown comprises a brake pad of any shape, shown schematically and not to scale for exemplary purposes only.

[0061] The brake element 1 comprises a metal support 2 , also called “back plate”, consisting of a flat metal plate delimited between two opposite, substantially flat faces, namely a first face 3 and a second face 4 substantially parallel to the face 3 .

[0062] The brake element 1 also includes: a friction material block (or pad) 5 known in the prior art and bonded to the second surface 4 in any suitable manner, which is designed to face the element to be braked when in use, such as a brake disc (not shown for simplicity); and a known anti-noise element 6 carried by the first surface 3 and covering all or at least part of the first surface 3.

[0063] An anti-noise element 6 , generally called a “shim”, is fixed to the face 3 in a stable manner such that the anti-noise shim 6 is applied to the support 2 on the side opposite to the block 5 of friction material.

[0064] According to the first aspect of the present invention, and with reference to Figure 2 , Figure 2 Shown at an appropriate scale Figure 6 The same cross section of the invention, but limited to the back plate 2 and the anti-noise gasket 6, which is bonded, in particular, by means of a layer 8 ( Figure 2) is fixed to the metal surface 7 of the first face 3 so that the gasket 6 is bonded to the first face 3 of the support member 2 opposite to the friction material block 5.

[0065] In a preferred embodiment of the invention, the adhesive or glue forming the layer 8 is an acrylic adhesive or glue, for example any commercial type of acrylic adhesive or glue.

[0066] In a preferred embodiment of the present invention, the first side 3 of the support 2 is painted with a first layer 9 of synthetic lacquer ( Figure 2 ).

[0067] In a preferred embodiment, layer 9 is formed from an epoxy lacquer, for example any commercial type of epoxy lacquer.

[0068] According to one main aspect of the invention, in order to promote a strong bond between the anti-noise gasket 6 and the metal surface 7 of the first face 3 of the metal support 2 , a second layer 10 of organic titanate is spread onto the first layer 9 of epoxy resin.

[0069] According to one aspect of the present invention, the organic titanate 10 (ie, forming the layer 10) contains an alkoxy group.

[0070] In this way, the anti-noise gasket 6 is bonded to the first face 3 by means of the third layer 8 of acrylic resin on the second layer 10 of organic titanate which, in the preferred embodiment shown, is on the layer 9 of synthetic lacquer epoxy resin.

[0071] As determined experimentally by applicant's technicians, this specifically selected sequence of specifically selected materials unexpectedly allows to avoid accidental detachment of the anti-noise gasket 6 from the backing plate 2 when in use, because the organic titanate forming layer 10 acts as a primer to promote adhesion.

[0072] In fact, at least a portion of the corresponding alkoxy groups of the organic titanate 10 can be hydrolyzed by both the acrylic resin 8 and the epoxy resin 9, thereby forming a chemical bond 11 between the first layer 9 and the third layer 8 ( Figure 2 ).

[0073] It is noted that the presence of the epoxy layer 9 may not be strictly necessary, even if it is strongly preferred.

[0074] According to a preferred embodiment of the present invention, the organic titanate 10 forming the second layer is a tetraalkoxytitanium (IV) represented by the following general formula:

[0075] [1]Ti(OR) 4 ,

[0076] Wherein, based on the surface chemical properties minus 8 and 9, R are all the same or different.

[0077] R is usually a single-chain or branched alkyl group, but may also have an amino group, a phosphine group, an ether group, or an unsaturated portion.

[0078] Therefore, R in formula [1] is preferably selected from:

[0079] - an unsubstituted alkyl group having a single chain or a branched chain;

[0080] - a substituted single-chain or branched alkyl group,

[0081] - Wherein the substituent is selected from: amino group, phosphoric acid group, ether group, unsaturated hydrocarbon group.

[0082] Preferred but non-limiting examples of organic titanates suitable for acting as primers according to the invention are selected from commercially available organic titanates usually used for completely different purposes, for example as catalysts:

[0083] - TnBT-Tetra-n-butyl titanate

[0084]

[0085] - BTP-Polymer Butyl Titanate

[0086] - TPT-(Tetraisopropyl Titanate)

[0087]

[0088] - TOT-Tetra-2-ethylhexyl titanate

[0089]

[0090] - TE-Triethanolamine titanate

[0091]

[0092] -Ken- 4,4-Isopropyl, tri(N-ethylenediamino)ethyl titanate

[0093]

[0094] -Ken- TTS-isopropyl, triisostearyl titanate

[0095]

[0096] -Ken- 138S-Bis(dioctyl pyrophosphate)titanium oxyacetate

[0097]

[0098] -Ken- 5,5-Tetrakis(2,2-diallyloxymethyl)butyl,di(ditridecyl)phosphite titanate

[0099]

[0100] Based on what has been described above, it is clear that the present invention also extends to a method for anchoring a covering sheet element 6 to a surface 7 of a metal support 2 of a brake element 1 by gluing such a covering sheet element 6 (where appropriate an anti-noise pad) to such a surface 7, comprising a step of pre-treating such a surface 7 before the gluing step; wherein:

[0101] i. The step of pre-treating such a surface 7 comprises applying a primer compound to the surface 7;

[0102] ii. The primer compound comprises an organic titanate 10 diluted (for easier application) in an organic solvent.

[0103] The organic titanate is a tetraalkoxytitanium (IV) represented by the above-mentioned general formula [1], wherein R are all the same or different and are represented by one of the above-mentioned alkyl groups.

[0104] In a preferred embodiment, the organic solvent is an alcoholic polar solvent.

[0105] In a preferred embodiment, the alcoholic polar solvent is selected from the group consisting of: isopropanol, ethanol, acetone, and mixtures thereof.

[0106] Reference Figure 7 , the method of the present invention preferably comprises the following steps:

[0107] a) First step 100, painting the surface 7 with epoxy resin 9;

[0108] b) a second step 200 of applying the selected organic titanate diluted in an organic solvent onto the surface 7 already coated with the epoxy resin 9, so as to form a uniform layer 10 of the organic titanate in solution on the surface 7 and on top of the epoxy resin 9, and then drying the layer 10;

[0109] c) A third step 300 of gluing the cover sheet element 6 to the surface 7 which has been pretreated with the lacquered organic titanate 10 diluted in an organic solvent by applying an acrylic glue or an acrylic resin-based adhesive 8 between the cover sheet element 6 and the uniform layer 10 of organic titanate.

[0110] The organic titanate 10 may be diluted in an alcohol polar solvent at a dilution of 0.5% v / v to 5% v / v.

[0111] The organic titanate 10 diluted in an organic solvent may be applied to the surface 7 using a technique selected from the following:

[0112] - by spraying a solution of organic titanate 10,

[0113] - by means of a roller (known and not shown for the sake of simplicity) coated with a solution of an organic titanate 10,

[0114] - By dropping the organic titanate 10 solution unevenly on the surface 7 and then distributing it evenly with a cloth or any type of cloth-covered applicator such as a rotating disk.

[0115] It is also obvious that the invention extends to a method for producing a brake element 1 comprising a support 2, a friction material block 5 bonded to the support 2 and an anti-noise element 6 also bonded to the support 2 on the side opposite to the friction material block 5, said method comprising all steps 100 to 300 as described above plus a step 400 of assembling the friction material block 5 onto the support 2 ( Figure 7 ).

[0116] Of course, step 400, although in Figure 7 In the example, the sequence of the steps 100 and 300 is shown only for the purpose of illustration, but is usually performed before step 100, i.e. upstream of step 100, so that the friction material block 5 is also fully or partially painted with epoxy resin 9. Instead, steps 100 to 300 are performed in the same manner as Figure 7 The same sequence as shown is performed.

[0117] Finally, it is evident that the invention also extends to the use of a primer compound for promoting the adhesion of an anti-noise sheet element or shim 6 to a surface 7 of a metal support 2 of a brake element 1 (in the preferred embodiment shown, the back plate 2 of a vehicle brake pad 1), wherein:

[0118] - the surface 7 may be coated with epoxy resin 9,

[0119] - the anti-noise gasket 6 can be glued to the surface 7 by means of acrylic glue 8 or an acrylic resin-based adhesive 8,

[0120] - the primer compound is spread on the epoxy lacquer 9 covering the surface 7 so as to be interposed between the epoxy 9 and the acrylic glue or adhesive 8;

[0121] - a primer compound comprising an organic titanate 10 diluted in an organic solvent, preferably an alcoholic polar solvent, which can be spread to form a uniform layer 10;

[0122] -Organo titanate is composed of the general formula Ti(OR) 4represents a tetraalkoxytitanium(IV) group, wherein R is as defined above.

[0123] In a preferred embodiment of the use according to the invention, the organic titanate is diluted in an alcoholic polar solvent at a dilution of 0.5% v / v to 5% v / v, then applied to the surface 7 before gluing the gasket 6 and dried at room temperature.

[0124] The invention will now be further described with reference to the following practical working examples which also clearly demonstrate the effectiveness of the invention, showing that the invention works effectively.

[0125] Example 1

[0126] The organic titanate, tetra-n-butyl titanate, was diluted in isopropyl alcohol at a dilution of 1% v / v and applied to the surface of a commercial backing plate designed to receive an anti-noise gasket.

[0127] The back panel is painted with commercial epoxy paint.

[0128] To apply the organotitanate, four drops of the organotitanate alcohol solution were poured onto the relevant surface and then spread manually over the entire surface with a cloth.

[0129] The applied organotitanate alcohol solution was dried for a few seconds (less than 10 seconds) at room temperature.

[0130] Thereafter, a commercial anti-noise gasket pre-glued with a commercial acrylic adhesive was applied on one side of its pre-glued face to the surface treated with the organic titanate, with a pressing time of 1 to 5 seconds and a pressure of 1000 to 2000 Kg.

[0131] Thereafter, adhesion was measured by lap shear strength and pull-off tests, the results being compared with the same tests applied to the same backsheet which had received the same pre-glued shim but without pre-treating the receiving surface of the backsheet with the organotitanate.

[0132] Example 2 - Pull-off Test

[0133] Test as Figure 3 The gasket 6 was attached to the surface 7 of both the bare (surface 7 without the organic titanate layer 10) and the surface 7 of the backing plate 2 pretreated with the organic titanate primer 10. After 24 hours, a portion of the gasket 6 was folded at 90°, as shown in FIG. Figure 3 shown.

[0134] Use force F A The adhesion of the anti-noise gasket 6 to the backing plate 2 (pretreated and unpretreated) was measured by pulling the anti-noise gasket 6 in a direction perpendicular to the surface 7 of the backing plate 2. The resulting force was calculated in N / mm using the following formula:

[0135] [2]pA=F A / l

[0136] Wherein pA is the pull-off force, and l is the width of the gasket 6 .

[0137] The results are reported in Table 1 below.

[0138] Table 1

[0139]

[0140] Example 3 - Lap Shear Test

[0141] Test as Figure 4 As in Example 2, the gasket 6 was placed on the surface 7 of both bare (surface 7 without organic titanate layer 10) and pre-treated with organic titanate primer 10 backing plates 2. After 24 hours, the backing plates 2 were subjected to an axial force F applied to the backing plates 2 in a direction parallel to the surface 7. A , so that the anti-noise gasket 6 is subjected to a shear stress pA. The resulting force is calculated using the following formula, in N / cm 2 count:

[0142] [3]pA=F A / l*m

[0143] Wherein pA is the lap shear force, l is the width of the gasket 6, and m is the length of the gasket 6 glued to the backboard.

[0144] The results are reported in Table 2 below.

[0145] Table 2

[0146]

[0147] Example 4 - T-Pull Test and Amount of Primer

[0148] The gasket 6 was attached to the backing plate surface 7 pre-treated with an organic titanate primer, which was commercial tetra-n-butyl titanate (Tyzor-TnBT) in isopropanol at different concentrations: 0.5% v / v, 1% v / v, 5% v / v and 10 v / v. After 24 hours, a portion of the gasket 6 was folded at 90°.

[0149] The adhesion of the anti-noise gasket 6 to the backing plate 2 was measured by pulling the anti-noise gasket 6 in a direction perpendicular to the backing plate surface 7 as described in Example 2. The resulting force was calculated using equation [2] and reported in Table 3 below.

[0150] Table 3

[0151]

[0152] It can be noted that the use of the organic titanate primer improves the adhesion of gasket 6 at all concentrations. However, the best performance is achieved at a concentration of 1%. The dilutions of 0.5%, 5% and 10% v / v do show that the applied force is lower than that obtained with the primer diluted at 1% v / v.

[0153] in conclusion

[0154] The use of an organic titanate primer provides a chemical bridge between the sub-layer and the bonding pad in a manner that allows the traditional burn-in treatment of epoxy paints to be eliminated.

[0155] Another advantage of using the method of the present invention is that the risk and cost of anti-noise gasket applications are reduced because the amount of organic titanate required is low.

[0156] In fact, it turns out that the alkoxy groups of the selected organotitanates are easily hydrolyzed by some of the groups present on the surface of the epoxy and acrylic resins. In this way, the connection points between the two resins increase and thus a wear-resistant bridge is formed between them.

[0157] The advantages of this solution are:

[0158] 1) Avoid burning.

[0159] 2) The adhesion of the gasket is improved in a timely manner through chemical bonds with both the epoxy resin of the backplane and the acrylic resin of the anti-noise gasket.

[0160] 3) Reduce the risk and cost of anti-noise gasket application.

[0161] Therefore, all objects of the present disclosure are achieved.

[0162] Certain terms

[0163] Although certain braking devices, systems, and methods have been disclosed in the context of certain exemplary embodiments, those skilled in the art will appreciate that the scope of the present disclosure extends beyond the specific disclosed embodiments to other alternative embodiments and / or uses of the embodiments and certain modifications and equivalents thereof, such as braking devices for brake drum-based braking systems. The use of any structure is clearly within the scope of the present invention. The various features and aspects of the disclosed embodiments may be combined or substituted with each other to form various modes of assembly. The scope of the present disclosure should not be limited by the specific disclosed embodiments described herein.

[0164] Unless otherwise specifically stated or understood otherwise in the context of use, conditional language such as "may," "can," "might," or "could" is generally intended to convey that certain embodiments include or do not include certain features, elements, and / or steps. Thus, such conditional language is generally not intended to imply that one or more embodiments require a feature, element, and / or step in any way.

[0165] Unless otherwise indicated, the terms "approximately," "about," and "substantially" as used herein refer to an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, in some embodiments, as the context may indicate, the terms "approximately," "about," and "substantially" may refer to an amount that is less than or equal to within 10% of the stated amount. Likewise, the term "generally," as used herein, refers to a value, amount, or characteristic that primarily includes or tends toward a particular value, amount, or characteristic.

[0166] The present disclosure clearly contemplates that the various features and aspects of the disclosed embodiments can be combined or substituted with each other. Therefore, the scope of the present disclosure should not be limited by the above-mentioned specific disclosed embodiments, but should only be determined by a reasonable interpretation of the full scope of the attached claims and their equivalents.

Claims

1. A method for anchoring a covering sheet element (6) to a surface (7) of a metal support (2) of a brake element (1) by gluing the covering sheet element (6) to the surface, comprising a step of pre-treating the surface (7) before the gluing step, characterized in that: i. the step of pretreating the surface (7) comprises applying a primer compound to the surface; ii. The primer compound comprises an organic titanate (10) diluted in an organic solvent.

2. The method according to claim 1, characterized in that the organic titanate (10) is a tetraalkoxytitanium (IV) represented by the general formula Ti(OR)4, wherein all R are the same or different, and are preferably selected from: unsubstituted single-chain or branched alkyl groups; substituted single-chain or branched alkyl groups, wherein the substituents are selected from amino groups, phosphoric acid groups, ether groups, and unsaturated hydrocarbon groups.

3. The method according to claim 1 or 2, characterized in that the organic solvent is an alcohol polar solvent.

4. The method according to claim 3, characterized in that the alcohol polar solvent is selected from: isopropanol, ethanol, acetone, and mixtures thereof.

5. The method according to any one of the preceding claims, characterized in that it comprises the steps of: a) painting (100) the surface with epoxy resin (9); b) applying (200) said organic titanate (10) in an organic solvent to said surface (7) already coated with said epoxy resin (9) to form a uniform layer of organic titanate (10) in solution on said surface and above said epoxy resin; c) gluing (300) the cover sheet element (6) to the surface (7) pretreated with the organic titanate (10) which has been painted and diluted in an organic solvent, by applying an acrylic glue or an acrylic resin-based adhesive (8) between the cover sheet element (6) and the uniform layer of the organic titanate (10) in solution.

6. A method according to any one of the preceding claims, characterized in that the covering sheet element comprises an anti-noise gasket (6), and the metal support comprises a back plate (2) of a vehicle brake pad (1), the surface (7) defining a first side (3) of the back plate (2) opposite to a second side (4) thereof carrying a friction material block (5); and the organic titanate (10) is diluted in an alcoholic polar solvent at a dilution of 0.5% v / v to 5% v / v.

7. A method according to any one of the preceding claims, characterised in that the organic titanate (10) diluted in an organic solvent is applied to the surface (7) using a technique selected from: - by spraying the organic titanate solution, - by means of a roller coated with the organic titanate solution, - By dropping the organotitanate solution unevenly on the surface and then distributing it evenly with a cloth or cloth-covered applicator.

8. A brake element (1), in particular a brake pad, comprising a support (2) for a block of friction material (5) and an anti-noise shim (6) applied to the support on the side opposite to the block of friction material, wherein the shim (6) is bonded to a first face (3) of the support opposite to the block of friction material, characterised in that, in combination: i) - the first surface (3) of the support is coated with a first layer of epoxy resin (9); ii) spreading a second layer of organic titanate (10) on the first layer of epoxy resin (9), wherein the organic titanate contains alkoxy groups; iii) - the spacer (6) is bonded to the first face (3) by means of a third layer of acrylic resin (8) located on the second layer of organic titanate (10); iv) - wherein at least a portion of the corresponding alkoxy groups have been hydrolyzed by both the acrylic resin (8) and the epoxy resin (9), thereby forming a chemical bond (11) between the first layer and the third layer.

9. The brake element according to claim 8, characterized in that the organic titanate (10) forming the second layer is a tetraalkoxytitanium (IV) represented by the general formula Ti(OR)4, wherein all R are the same or different and are preferably selected from: unsubstituted single-chain or branched alkyl groups; substituted single-chain or branched alkyl groups, wherein the substituents are selected from: amino groups, phosphoric acid groups, ether groups, unsaturated hydrocarbon groups.

10. Use of a primer compound for promoting the adhesion of an anti-noise sheet element (6) or an anti-noise shim to the surface (7) of a metal support (2) of a brake element (1), in particular a back plate of a vehicle brake pad, wherein: - said surface (7) is coated with epoxy resin (9), - the anti-noise gasket (6) is glued to the surface by means of acrylic glue or an acrylic resin-based adhesive (8), Features i) - spreading the primer compound on the epoxy lacquer layer (10) covering the surface (7) so as to be interposed between the epoxy resin (9) and the acrylic glue or adhesive (8); ii) - the primer compound comprises an organic titanate (10) diluted in an organic solvent, preferably an alcoholic polar solvent; iii) - The organic titanate (10) is a tetraalkoxytitanium (IV) represented by the general formula Ti(OR)4, wherein all R are the same or different, and are preferably selected from: unsubstituted single-chain or branched alkyl groups; substituted single-chain or branched alkyl groups, wherein the substituents are selected from: amino groups, phosphoric acid groups, ether groups, and unsaturated hydrocarbon groups.

11. The use according to claim 10, wherein the organic titanate (10) is diluted in an alcoholic polar solvent at a dilution of 0.5% v / v to 5% v / v, then applied to the surface (7) and left to dry at room temperature.

12. A method for producing a brake element (1), the brake element comprising a support (2), a friction material block (5) bonded to the support and an anti-noise element (6) also bonded to the support on the side opposite to the friction material block, the method comprising all the steps of the method according to claims 1 to 7 plus a step (400) of assembling the friction material block (5) onto the support (2).

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