FR3151598A1 - Aqueous adhesive composition comprising a viscosity-enhanced polyvinyl alcohol-based resin - Google Patents

Abstract

The invention relates to an aqueous adhesive composition comprising a thermosetting resin based on: - at least one compound A1, the compound A1 comprising at least one aldehyde function; - at least one phenol compound A21; - at least one polyvinyl alcohol A3; and - at least one unsaturated elastomer latex comprising at least one elastomer chosen from the group consisting of butadiene copolymers, styrene-butadiene copolymers, vinylpyridine-styrene-butadiene terpolymers, natural rubber with the exception of chlorinated natural rubber, and mixtures of these elastomers; the content of compound A3 in the aqueous adhesive composition being at a mass rate ranging from 0.05% to 0.20%.

Description

Aqueous adhesive composition comprising a viscosity-enhanced polyvinyl alcohol-based resin

The field of the present invention is that of Glass-Resin composites, abbreviated to “CVR”, and adhesive compositions or “glues” intended to adhere such elements to elastomeric matrices such as those commonly used in elastomer articles or semi-finished products or in the field of non-pneumatic tires.

The present invention relates more particularly to a new aqueous adhesive composition allowing optimal and homogeneous bonding of the glass-resin composite.

Known from the state of the art is an aqueous adhesive composition used for the conventional bonding process for glass-resin composites as described in application WO2016116457, for example adhesive compositions known under the name “RFL” (for resorcinol-formaldehyde-latex), as for example described in EP2006341, mixed with an aqueous solution based on blocked diisocyanate, then mixed in an elastomeric matrix with a 100% vinylpyridine latex phase.

However, the CVR composite is very different from a classic textile reinforcement because it will not absorb liquids because of its structure based on glass fiber and crosslinked resin. The problem is then to succeed in obtaining a clean and homogeneous bonding state all around the composite in order to ensure optimal adhesion with the elastomeric composition knowing that the known aqueous adhesive compositions have a very low viscosity, close to that of water. When the composite passes into the aqueous adhesive composition tank, it takes aqueous adhesive composition which then has time to flow onto the composite before entering the drying oven.

One solution to this problem is to perform vertical gluing of the CVR composite. This limits the presence of drops and inhomogeneity above/below the composite but does not completely eliminate the problem of clean and homogeneous gluing all around the composite.

The aim of the invention is to provide an aqueous adhesive composition, comprising a thermosetting resin, having high adhesive properties and offering an improved viscosity compared to that of document WO2016116457.

However, during its research, the Applicant discovered an aqueous adhesive composition of higher viscosity, which makes it possible to meet the above objective.

Thus, an object of the invention relates to an aqueous adhesive composition, comprising a thermosetting resin based on:
- at least one compound A1, the compound A1 comprising at least one aldehyde function;
- at least one phenol A21 compound;
- at least one polyvinyl alcohol A3; and
- at least one unsaturated elastomer latex comprising at least one elastomer selected from the group consisting of butadiene copolymers, styrene-butadiene copolymers, vinylpyridine-styrene-butadiene terpolymers, natural rubber with the exception of chlorinated natural rubber, and mixtures of these elastomers;
the content of compound A3 in the aqueous adhesive composition being at a mass rate ranging from 0.05% to 0.20%.

By mass rate of compound A3 is meant the ratio between the mass of compound A3 after drying of the adhesive composition and the mass of the adhesive composition before drying.

This dry extract rate is measured in accordance with standard NF EN 827 (March 2006).

The Applicant thus hypothesizes that the addition of compound A3 to the aqueous adhesive composition will make it possible to increase the viscosity without, however, altering the adhesive properties of the composite with respect to the elastomeric composition.

The invention also relates to a Glass-Resin CVR composite bonded with a layer of composition as described above.

The invention also relates to a method for bonding one or more strands of Glass-Resin composite, abbreviated to “CVR”, characterized in that it comprises the following steps:
a) a pre-adhesion step is carried out on one or more strands of CVR composite by dipping the strand(s) in a first aqueous bath comprising a composition based on:
- an epoxy compound; and
- a blocked diisocyanate compound;
b) a deposition step is carried out on the CVR composite strand(s) by dipping the CVR composite strand(s) in a second bath comprising the aqueous adhesive composition as described above.

The invention also relates to an elastomer composite reinforced with at least one or more strands of glued CVR Glass-Resin composite embedded in an elastomer matrix, in which the strand(s) of glued CVR Glass-Resin composite are obtained by the method as described above.

The composite according to the invention thus manufactured can be advantageously used, in particular for the reinforcement of tires, pneumatic or non-pneumatic, of all types of vehicles, in particular passenger vehicles or industrial vehicles such as heavy goods vehicles, civil engineering, aircraft, other transport or handling vehicles.

The invention also relates to a non-pneumatic tire comprising the elastomer composite as described above.

Any interval of values denoted by the expression "between a and b" represents the domain of values from plus a to minus b (i.e., excluding the limits a and b), while any interval of values denoted by the expression "from a to b" signifies the domain of values from a to b (i.e., including the strict limits a and b).

In the context of the invention, the carbon products mentioned in the description may be of fossil or bio-sourced origin. In the latter case, they may be, partially or totally, derived from biomass or obtained from renewable raw materials derived from biomass.

In this description, unless expressly indicated otherwise, all percentages (%) indicated are % by mass.

By elastomer composition is meant a composition comprising at least one elastomer (or indistinctly rubber) and at least one other constituent.

By "diene" elastomer (or indistinctly rubber) is meant an elastomer derived at least in part (i.e. a homopolymer or a copolymer) from diene monomer(s) (i.e., bearing(s) two carbon-carbon double bonds, conjugated or not). By "isoprene elastomer" is meant a homopolymer or a copolymer of isoprene, in other words a diene elastomer chosen from the group consisting of natural rubber (NR), synthetic polyisoprenes (IR), the various isoprene copolymers and the mixtures of these elastomers.

By elastomeric matrix we mean a matrix with elastomeric behavior.

By "position meta to each other" we mean that the hydroxyl functions are carried by carbons of the aromatic nucleus separated from each other by a single other carbon of the aromatic nucleus.

By "in the ortho position of a function" we mean the position occupied by the carbon of the aromatic ring immediately adjacent to the carbon of the aromatic ring carrying the function.

By "member" of a ring is meant a constituent atom of the skeleton of the ring. Thus, for example, a benzene ring has six members, each member consisting of a carbon atom. In another example, a furan ring has five members, four members each consisting of a carbon atom and the remaining member consisting of an oxygen atom.

“CHO” represents the aldehyde function.

“CH2OH” represents the hydroxymethyl function.

By “aromatic polyphenol” is meant an aromatic compound comprising at least one benzene nucleus carrying more than one hydroxyl function.

By "resin based on" it is meant that the resin comprises the mixture and/or the reaction product of the various basic constituents used for this resin as defined above and that this resin is solely based on the constituents of the resin. Thus the basic constituents are the reactants intended to react together during the final condensation of the resin and are not reactants intended to react together to form these basic constituents.

According to the invention, the basic constituents of the aqueous adhesive composition therefore comprise at least one compound A1, at least one phenol compound A21 and at least one polyvinyl alcohol compound A3. In one embodiment, the basic constituents may comprise other additional constituents different from the compound, the phenol compound A21 and the compound A3. In another embodiment, the basic constituents consist of at least one compound A1, at least one phenol compound A21 and at least one compound A3.

Preferably, in the embodiment where the base components comprise other additional components, these other additional components are free of formaldehyde and/or free of a methylene donor selected from the group consisting of hexa-methylenetetramine (HMT), hexamethoxymethylmelamine (H3M), hexaethoxymethylmelamine, lauryloxymethylpyridinium chloride, ethoxymethylpyridinium chloride, hexamethoxymethylmelamine polymers of formaldehyde trioxane, hexakis(methoxymethyl)melamine, N,N',N"-trimethyl/-N,N',N"-trimethylolmelamine, hexamethylolmelamine, N-methylolmelamine, N,N'-dimethylolmelamine, N,N',N"-tris(methoxymethyl)melamine, N,N',N"-tributyl-N,N',N"-trimethylolmelamine. More advantageously, these other additional constituents are free of formaldehyde and free of the methylene donors described in this paragraph.

More preferably, in the embodiment where the basic constituents comprise other additional constituents, these other additional constituents are free of formaldehyde and/or free of methylene donor selected from the group consisting of hexamethylenetetramine, hexaethoxymethylmelamine, hexamethoxymethylmelamine, lauryloxymethylpyridinium chloride, ethoxymethylpyridinium chloride, trioxane hexamethoxymethylmelamine and N-substituted oxymethylmelamines corresponding to the general formula:

in which Q represents an alkyl group containing from 1 to 8 carbon atoms; F ₁ , F ₂ , F3, F ₄ and F ₅ are selected, independently of one another, from the group consisting of a hydrogen atom, an alkyl group containing from 1 to 8 carbon atoms, the group -CH2OQ and their condensation products. More advantageously, these other additional constituents are free of formaldehyde and free of the methylene donors described in this paragraph.

Even more preferably, in the embodiment where the basic constituents comprise other additional constituents, these other additional constituents are free of formaldehyde and/or free of methylene donor. More advantageously, these other additional constituents are free of formaldehyde and free of methylene donors.

By formaldehyde-free or methylene donor-free, it is meant that the total mass content of formaldehyde or methylene donor(s) belonging to the groups described above by total weight of the compound(s) A1 in the basic constituents is less than or equal to 10%, preferably 5%, more preferably 2% and even more preferably 1%.

By formaldehyde-free and methylene donor-free, it is meant that the total mass content of formaldehyde and of the methylene donor(s) belonging to the groups described above by total weight of the compound(s) A1 in the basic constituents is less than or equal to 10%, preferably 5%, more preferably 2% and even more preferably 1%.

Glass-resin composite strands CVR are understood to mean composite reinforcements based on single strands of the CVR type comprising continuous, unidirectional multifilament glass fibres embedded in a thermoset resin and usable in particular as tyre reinforcement elements.

COMPOSITION ACCORDING TO THE INVENTION

According to the invention, the basic constituents of the resin therefore comprise at least one compound A1, at least one phenol compound A2 and at least one compound A3. In one embodiment, the basic constituents may comprise other additional constituents different from the compound A1, the phenol compound A2 and the compound A3. In another embodiment, the basic constituents consist of at least one compound A1 and at least one phenol compound A2 and at least one compound A3.

According to the invention, the aqueous adhesive composition is prepared so that the content of compound A3 in the aqueous adhesive composition is at a mass rate ranging from 0.05% to 0.20%.

Compound A1

An essential constituent of the adhesive composition is a compound A1, the compound A1 comprising at least one aldehyde function.

According to the invention, the resin is based on at least one (i.e. one or more) compounds A1.

In a first embodiment, compound A1 is formaldehyde.

In a second embodiment, the compound A1 comprises at least one aromatic nucleus carrying at least one aldehyde function.

More preferably, compound A1 carries at least two aldehyde functions.

Even more preferentially, the aromatic nucleus of compound A1 carries two aldehyde functions.

In one embodiment, the aromatic nucleus of compound A1 is selected from the group consisting of a benzene nucleus and a furan nucleus, preferably the aromatic nucleus of the aromatic aldehyde is a benzene nucleus.

Preferably, compound A1 is selected from the group consisting of 1,2-benzene-dicarboxaldehyde, 1,3-benzene-dicarboxaldehyde, 1,4-benzene-dicarboxaldehyde, 2-hydroxybenzene-1,3,5-tricarbaldehyde and mixtures of these compounds.

In a variant of the second embodiment, the compound A1 is of general formula (A ) :

in which:
X includes N, S or O
R represents -H or –CHO.

Preferably, compound A1 is of general formula (A' ) :

in which X represents O.

Even more preferably, R represents -CHO.

According to a preferred embodiment, X represents O.

In a variant of compound A1 of general formula (A) , X represents O and R represents –H. The compound A1 used is then of formula (Ba ) :

In a variant of the aldehyde of general formula (A') , X represents O and R represents –H. The compound A1 used is then furfuraldehyde and is of formula ( B'a ) :

In another variant of compound A1 of general formula (A) , X represents O and R represents –CHO. The compound A1 used is then of formula ( Bb ) :

In another variant of compound A1 of general formula (A') , X represents O and R represents –CHO. The compound A1 used is then 2,5-furanedicarboxaldehyde and is of formula ( B'b ) :

In another embodiment, X comprises N.

Preferably, compound A1 is selected from the group consisting of furfuraldehyde, 2,5-furanedicarboxaldehyde and mixtures of these compounds.

In a variant of compound A1 of general formula (A) , X represents NH. Compound A12 used is of formula (Ca ) :

In a variant of compound A1 of general formula (A') , X represents NH. Compound A12 used is of formula (C'a ) :

Preferably, R represents –CHO in the variant of compound A12 of formula (C'a) and the compound A12 obtained is then 2,5-1H-pyrroledicarboxaldehyde.

In another variant of compound A1 of general formula (A) , X represents NT ₁ with T ₁ representing an alkyl, aryl arylalkyl, alkylaryl or cycloalkyl group. Compound A12 used is of formula (Cb ) :

In another embodiment, X comprises S.

In a variant of compound A1 of general formula (A) , X represents S. Compound A12 used is of formula (Da ) :

In a variant of compound A1 of general formula (A') , X represents S. Compound A12 used is of formula (D'a ) :

Preferably, R represents –CHO in the variant of compound A1 of formula ( IV'a ) and is then 2,5-thiophenedicarboxaldehyde.

In another variant of compound A1 of general formula (A) , X represents ST ₂ with T ₂ representing an alkyl, aryl arylalkyl, alkylaryl or cycloalkyl group. Compound A12 used is of formula ( Db ) :

In yet another variant of compound A1 of general formula (A) , X represents _T3 - _ST2 with _T2 , _T3 each independently representing an alkyl, aryl, arylalkyl, alkylaryl or cycloalkyl group. Compound A1 used is of formula ( Dc ) :

In yet another variant of compound A1 of general formula (A) , X represents S=O. Compound A12 used is of formula (Dd ) :

In yet another variant of compound A1 of general formula (A) , X represents O=S=O. Compound A12 used is of formula (De ) :

Among the various embodiments described above, the embodiments and variants in which X represents NH, S or O will be preferred. In these embodiments and variants, R may represent –H or –CHO and preferably R represents –CHO. In these embodiments and variants, R will preferably be in position 5 and the –CHO group in position 2 on the aromatic nucleus (general formula (A') ).

Compound p h eno L A21

According to the invention, the resin is based on at least one (i.e. one or more) phenol A21 compounds.

• un polyphénol aromatique A2 comprenant au moins un noyau aromatique porteur d’au moins deux fonctions hydroxyle en position méta l’une par rapport à l’autre, les deux positions ortho d’au moins une des fonctions hydroxyle étant non substituées
• un monophénol aromatique A2’ comprenant au moins un noyau aromatique à six chaînons portant une unique fonction hydroxyle,

• les deux positions ortho de la fonction hydroxyle étant non substituées ou
• au moins une position ortho et la position para de la fonction hydroxyle étant non substituées

• un mélange de A2 et A2’.

Advantageously, the phenol compound A21 is chosen from:

• an aromatic polyphenol A2 comprising at least one aromatic nucleus carrying at least two hydroxyl functions in meta position relative to each other, the two ortho positions of at least one of the hydroxyl functions being unsubstituted
• an aromatic monophenol A2' comprising at least one six-membered aromatic ring carrying a single hydroxyl function,

• the two ortho positions of the hydroxyl function being unsubstituted or
• at least one ortho position and the para position of the hydroxyl function being unsubstituted

• a mixture of A2 and A2'.

In one embodiment, the phenol is an aromatic polyphenol A2 comprising one or more aromatic nuclei. The aromatic polyphenol comprises at least one aromatic nucleus bearing at least two hydroxyl functions in meta position relative to each other, the two ortho positions of at least one of the hydroxyl functions being unsubstituted.

In another embodiment, the phenol is an aromatic monophenol A2’ comprising at least one six-membered aromatic ring carrying a single hydroxyl function. On this aromatic monophenol, the two ortho positions of the hydroxyl function are unsubstituted, or at least one ortho position and the para position of the hydroxyl function are unsubstituted.

In yet another embodiment, the phenol is a mixture of the aromatic polyphenol A2 and the aromatic monophenol A2' as described above.

In accordance with the invention, the aromatic polyphenol A2 may be, in one embodiment, a simple molecule of aromatic polyphenol comprising one or more aromatic nuclei, at least one of these aromatic nuclei, or even each aromatic nucleus, carrying at least two hydroxyl functions in meta position relative to each other, the two ortho positions of at least one of the hydroxyl functions being unsubstituted.

Similarly, the aromatic monophenol A2' may be, in one embodiment, a simple molecule of aromatic monophenol comprising one or more six-membered aromatic rings, at least one of these six-membered aromatic rings, or even each six-membered aromatic ring, carrying a single hydroxyl function, the two ortho positions of the hydroxyl function being unsubstituted, or at least one ortho position and the para position of the hydroxyl function are unsubstituted.

Such simple molecules do not include a repeating unit.

• d’au moins un polyphénol aromatique, comprenant au moins un noyau aromatique porteur d’au moins deux fonctions hydroxyle en position méta l’une par rapport à l’autre, les deux positions ortho d’au moins une des fonctions hydroxyle étant non substituées ; et
• d’au moins un composé comprenant au moins une fonction aldéhyde et/ou au moins un composé comprenant au moins deux fonctions hydroxyméthyle portées par un noyau aromatique.

According to the invention, the aromatic polyphenol A2 may be, in another embodiment, a pre-condensed resin based on:

• of at least one aromatic polyphenol, comprising at least one aromatic nucleus carrying at least two hydroxyl functions in meta position relative to each other, the two ortho positions of at least one of the hydroxyl functions being unsubstituted; and
• of at least one compound comprising at least one aldehyde function and/or at least one compound comprising at least two hydroxymethyl functions carried by an aromatic nucleus.

Such a pre-condensed resin based on aromatic polyphenol is in accordance with the invention and comprises, unlike the simple molecule described above, a repeating unit. In this case, the repeating unit comprises at least one aromatic nucleus carrying at least two hydroxyl functions in the meta position relative to each other.

Similarly and in accordance with the invention, the aromatic monophenol A2' may be, in another embodiment, a pre-condensed resin based on:
- at least one aromatic monophenol comprising at least one six-membered aromatic ring carrying a single hydroxyl function:
- both ortho positions of the hydroxyl function are unsubstituted, or
- at least one ortho position and the para position of the hydroxyl function are unsubstituted;
- at least one compound comprising at least one aldehyde function and/or at least one compound comprising at least two hydroxymethyl functions carried by an aromatic nucleus.

Such a pre-condensed resin based on aromatic monophenol is in accordance with the invention and comprises, unlike the simple molecule described above, a repeating unit. In this case, the repeating unit comprises at least one six-membered aromatic nucleus carrying a single hydroxyl function.

In another embodiment, the phenol compound A21 is a mixture of a single molecule aromatic polyphenol and a pre-condensed aromatic polyphenol-based resin.

In yet another embodiment, the phenol compound A21 is a mixture of a single molecule aromatic monophenol and a pre-condensed aromatic monophenol resin.

In the following particular embodiments, the aromatic ring(s) of the aromatic polyphenol and/or aromatic monophenol are described. For the sake of clarity, the “aromatic polyphenol” and/or “aromatic monophenol” is described in its single molecule form. This aromatic polyphenol and/or aromatic monophenol may then be condensed and will partly define the repeating unit. The characteristics of the pre-condensed resin are described in more detail below.

Aromatic polyphenol A2

In a preferred embodiment, the aromatic nucleus of the aromatic polyphenol carries three hydroxyl functions in meta position relative to each other.

Preferably, the two ortho positions of each hydroxyl function are unsubstituted. This means that the two carbon atoms located on either side (in the ortho position) of the hydroxylated carbon atom (i.e., carrying the hydroxyl function) carry a single hydrogen atom.

Even more preferably, the remainder of the aromatic nucleus of the aromatic polyphenol is unsubstituted. This means that the other carbon atoms of the remainder of the aromatic nucleus (those other than the carbon atoms carrying the hydroxyl functions) carry a single hydrogen atom.

In one embodiment, the aromatic polyphenol comprises several aromatic rings, at least two of which each carry at least two hydroxyl functions in meta position relative to each other, the two ortho positions of at least one of the hydroxyl functions of at least one aromatic ring being unsubstituted.

In a preferred embodiment, at least one of the aromatic nuclei of the aromatic polyphenol carries three hydroxyl functions in meta position relative to each other.

Preferably, both ortho positions of each hydroxyl function of at least one aromatic ring are unsubstituted.

Even more preferably, the two ortho positions of each hydroxyl function of each aromatic nucleus are unsubstituted.

Advantageously, the or each aromatic nucleus of the aromatic polyphenol is a benzene nucleus.

As an example of an aromatic polyphenol comprising a single aromatic nucleus, we can cite in particular, resorcinol and phloroglucinol, as a reminder of the developed formulas respectively (IV) and (V):

As examples, in the case where the aromatic polyphenol comprises several aromatic nuclei, at least two of these aromatic nuclei, identical or different, are chosen from those of general formulas:

in which the symbols Z ₁ , Z ₂ , identical or different if they are several on the same aromatic nucleus, represent an atom (for example carbon, sulfur or oxygen) or a linking group by definition at least divalent, which links at least these two aromatic nuclei to the rest of the aromatic polyphenol.

Another example of an aromatic polyphenol is 2,2',4,4'-tetrahydroxydiphenyl sulfide with the following structural formula (VII):

Another example of an aromatic polyphenol is 2,2',4,4'-tetrahydroxydiphenyl benzophenone with the following structural formula (VIII):

It is noted that each compound VII and VIII is an aromatic polyphenol comprising two aromatic nuclei (of formulas VI-c) each of which carries at least two (in this case two) hydroxyl functions in the meta position relative to each other.

It is noted that in the case of an aromatic polyphenol comprising at least one aromatic nucleus in accordance with formula VI-b, the two ortho positions of each hydroxyl function of at least one aromatic nucleus are unsubstituted. In the case of an aromatic polyphenol comprising several aromatic nuclei in accordance with formula VI-b, the two ortho positions of each hydroxyl function of each aromatic nucleus are unsubstituted.

According to one embodiment of the invention, the aromatic polyphenol is selected from the group consisting of resorcinol, phloroglucinol, 2,2',4,4'-tetrahydroxydiphenyl sulfide, 2,2′,4,4′-tetrahydroxybenzophenone, and mixtures of these compounds.

In a particularly advantageous embodiment, the aromatic polyphenol is phloroglucinol.

In one embodiment, the aromatic polyphenol A2 comprises a pre-condensed resin based on the aromatic polyphenol as described in any of these embodiments.

• d’au moins un polyphénol aromatique tel que défini précédemment, et préférentiellement choisi dans le groupe constitué par le résorcinol, le phloroglucinol, le 2,2',4,4'-tétrahydroxydiphényl sulfide , la 2,2′,4,4′-tétrahydroxybenzophenone, et leurs mélanges ; et
• d’au moins un composé susceptible de réagir avec le polyphénol aromatique comprenant au moins une fonction aldéhyde et/ou au moins un composé susceptible de réagir avec le polyphénol aromatique comprenant au moins deux fonctions hydroxyméthyle, et préférentiellement un aldéhyde aromatique comprenant au moins un noyau aromatique porteur d’au moins une fonction aldéhyde.

This pre-condensed resin is advantageously based on:

• of at least one aromatic polyphenol as defined above, and preferably chosen from the group consisting of resorcinol, phloroglucinol, 2,2',4,4'-tetrahydroxydiphenyl sulfide, 2,2′,4,4′-tetrahydroxybenzophenone, and mixtures thereof; and
• of at least one compound capable of reacting with the aromatic polyphenol comprising at least one aldehyde function and/or at least one compound capable of reacting with the aromatic polyphenol comprising at least two hydroxymethyl functions, and preferably an aromatic aldehyde comprising at least one aromatic nucleus carrying at least one aldehyde function.

The compound capable of reacting with the aromatic polyphenol with the compound A1 may be an aromatic compound as defined above or any other aldehyde. Advantageously, said compound is chosen from the group consisting of an aromatic compound comprising an aromatic nucleus carrying at least two functions, one of these functions being a hydroxymethyl function, the other being an aldehyde function or a hydroxymethyl function, formaldehyde, furfuraldehyde, 2,5-furanedicarboxaldehyde, 1,4-benzenedicarboxaldehyde, 1,3-benzenedicarboxaldehyde, 1,2-benzenedicarboxaldehyde and mixtures of these compounds. Very advantageously, when the compound capable of reacting with the aromatic polyphenol is an aromatic compound comprising an aromatic nucleus carrying at least two functions, one of these functions being a hydroxymethyl function, the other being an aldehyde function or a hydroxymethyl function, this compound is chosen from the group consisting of 5-(hydroxymethyl)-furfural, 2,5-di(hydroxymethyl)furan and mixtures of these compounds.

Thus, in the pre-condensed resin based on aromatic polyphenol, the repeating unit meets the characteristics of the aromatic polyphenol defined previously except that at least one of the carbon atoms of the aromatic nucleus, which was unsubstituted, is linked to another unit.

Regardless of the compound other than the aromatic polyphenol at the base of the pre-condensed resin, this pre-condensed resin is free of free formaldehyde. Indeed, even in the case where the pre-condensed resin is based on an aromatic polyphenol as described above and formaldehyde, the formaldehyde having already reacted with the aromatic polyphenol, the pre-condensed resin is free of free formaldehyde capable of being able to react with a compound A1 in accordance with the invention in a subsequent step.

The aromatic polyphenol A2 may also comprise a mixture of a free molecule of aromatic polyphenol and a pre-condensed resin based on aromatic polyphenol, as described above. In particular, the aromatic polyphenol A2 may also comprise a mixture of phloroglucinol and a pre-condensed resin based on phloroglucinol.

Mono phenol aromatic A2 ’

The aromatic monophenol A2’ may be in accordance with two variants. In one variant, both ortho positions of the hydroxyl function are unsubstituted. In another variant, at least one ortho position and the para position of the hydroxyl function are unsubstituted.

Advantageously, in the variant in which at least one ortho position and the para position of the hydroxyl function are unsubstituted, a single ortho position is unsubstituted and the para position of the hydroxyl function is unsubstituted.

Preferably, regardless of the variant, the two ortho positions of the hydroxyl function are unsubstituted. This means that the two carbon atoms located on either side (in the ortho position) of the hydroxylated carbon atom (i.e., carrying the hydroxyl function) carry a single hydrogen atom.

Even more preferably, the remainder of the aromatic nucleus is unsubstituted. This means that the other carbon atoms of the remainder of the aromatic nucleus (those other than the carbon atoms carrying the hydroxyl functions) carry a single hydrogen atom.

In one embodiment, the aromatic monophenol comprises a plurality of six-membered aromatic rings, at least two of which each carry a single hydroxyl function and, for at least one of the hydroxyl functions, both ortho positions of the hydroxyl function are unsubstituted, or at least one ortho position and the para position of the hydroxyl function are unsubstituted.

Preferably, both ortho positions of each hydroxyl function of at least one six-membered aromatic ring are unsubstituted.

Even more preferably, the two ortho positions of each hydroxyl function of each six-membered aromatic ring are unsubstituted.

Even more preferably, the remainder of each of the aromatic nuclei is unsubstituted. This means that the other carbon atoms of the remainder of each aromatic nucleus (those other than the carbon atoms carrying the hydroxyl functions or carrying the group linking the aromatic nuclei together) carry a single hydrogen atom.

Advantageously, the or each aromatic nucleus of the aromatic monophenol is a benzene nucleus.

Preferably, the aromatic monophenol is selected from the group consisting of phenol, ortho cresol, meta cresol, para cresol, ortho chlorophenol, meta chlorophenol, para chlorophenol, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 4-vinylphenol, 4-ethylphenol, 4-isopropylphenol, 4-isobutylphenol, paracoumaric acid and mixtures of these compounds.

In one embodiment, the aromatic monophenol A2' comprises a pre-condensed resin based on the aromatic monophenol as described in any of these embodiments.

• d’au moins un monophénol aromatique tel que défini précédemment, et préférentiellement choisi dans le groupe constitué par le phénol, l’ortho crésol, le méta crésol, le para crésol, l’ortho chlorophénol, le méta chlorophénol, le para chlorophénol, l’acide 2-hydroxybenzoïque, l’acide 3-hydroxybenzoïque, l’acide 4-hydroxybenzoïque le 4-vinylphénol, le 4-éthylphénol, le 4-isopropylphénol, le 4-isobutylphénol, l’acide paracoumarique et les mélanges de ces composés ; et
• d’au moins un composé susceptible de réagir avec le monophénol aromatique comprenant au moins une fonction aldéhyde et/ou au moins un composé susceptible de réagir avec le monophénol aromatique comprenant au moins deux fonctions hydroxyméthyle, et préférentiellement un aldéhyde aromatique comprenant au moins un noyau aromatique porteur d’au moins une fonction aldéhyde.

This pre-condensed resin is advantageously based on:

• of at least one aromatic monophenol as defined above, and preferably chosen from the group consisting of phenol, ortho cresol, meta cresol, para cresol, ortho chlorophenol, meta chlorophenol, para chlorophenol, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 4-vinylphenol, 4-ethylphenol, 4-isopropylphenol, 4-isobutylphenol, paracoumaric acid and mixtures of these compounds; and
• of at least one compound capable of reacting with the aromatic monophenol comprising at least one aldehyde function and/or at least one compound capable of reacting with the aromatic monophenol comprising at least two hydroxymethyl functions, and preferably an aromatic aldehyde comprising at least one aromatic nucleus carrying at least one aldehyde function.

The compound capable of reacting with the aromatic monophenol may be a compound A1 as defined above or any other aldehyde. Advantageously, said compound capable of reacting with the aromatic polyphenol is chosen from the group consisting of an aromatic compound comprising an aromatic nucleus bearing at least two functions, one of these functions being a hydroxymethyl function, the other being an aldehyde function or a hydroxymethyl function, formaldehyde, furfuraldehyde, 2,5-furanedicarboxaldehyde, 1,4-benzenedicarboxaldehyde, 1,3-benzenedicarboxaldehyde, 1,2-benzenedicarboxaldehyde and mixtures of these compounds. Very advantageously, when the compound is an aromatic compound comprising an aromatic nucleus carrying at least two functions, one of these functions being a hydroxymethyl function, the other being an aldehyde function or a hydroxymethyl function, this compound is chosen from the group consisting of 5-(hydroxymethyl)-furfural, 2,5-di(hydroxymethyl)furan and mixtures of these compounds.

Thus, in the pre-condensed aromatic monophenol resin, the repeating unit meets the characteristics of the aromatic monophenol defined above except that at least one of the carbon atoms of the six-membered aromatic ring, which was unsubstituted, is linked to another unit.

Regardless of the compound other than the aromatic monophenol at the base of the pre-condensed resin, this pre-condensed resin is free of free formaldehyde. Indeed, even in the case where the pre-condensed resin is based on an aromatic monophenol as described above and formaldehyde, the formaldehyde having already reacted with the aromatic monophenol, the pre-condensed resin is free of free formaldehyde capable of being able to react with a compound A1 in accordance with the invention in a subsequent step.

The aromatic monophenol A2’ may also comprise a mixture of a free molecule of aromatic monophenol and a pre-condensed resin based on aromatic monophenol, as described above. In particular, the aromatic monophenol A2’ may also comprise a mixture of phenol and a pre-condensed resin based on phenol.

Mixture of aromatic polyphenol A2 and mono phenol aromatic A2 ’

The phenol compound A21 may also comprise a mixture of an aromatic polyphenol A2 and an aromatic monophenol A2', as previously described.

Preferably, the phenol compound A21 comprises a mixture of aromatic polyphenol and a pre-condensed aromatic polyphenol-based resin.

Compound A3

According to the invention, the resin is based on at least one (i.e. one or more) compounds A3.

Compound A3 is polyvinyl alcohol of formula –(CH2CHOH)n–. This polymer is obtained in particular by alkaline hydrolysis (soda, potash) of polyvinyl acetate of formula –(CH2CHOAc)n–.

It is also known as PVOH: polyvinyl alcohol.

Preferably, the content of compound A3 in the aqueous adhesive composition is at a mass rate ranging from 0.10% to 0.20% and preferably from 0.10% to 0.15%.

For rates greater than 0.05%, the presence of PVOH already makes it possible to significantly increase the viscosity of the aqueous adhesive composition and if the rate is greater than 0.20%, the viscosity becomes too high and the solutions sometimes become unstable. Over the preferred range from 0.10% to 0.20%, the person skilled in the art, depending on the constituents A1 and A21, can choose the best viscosity compromise to obtain a clean and homogeneous bond all around the composite in order to ensure optimum adhesion with the elastomeric composition.

Lat ex elastomer

The adhesive composition also comprises an elastomer latex, preferably unsaturated. Such an elastomer latex makes it possible to provide an elastomeric physical interface when the adhesive composition is used for coating elements intended to be embedded in an elastomer matrix. When the elastomer latex is unsaturated, it also provides a chemical interface thanks to the unsaturations capable of forming bridges with the crosslinking system of the elastomer matrix.

It is recalled that a latex is a stable dispersion of microparticles of elastomer(s) suspended in a generally aqueous solution. An elastomer latex is therefore a composition in a liquid state comprising a liquid solvent, generally water, and at least one elastomer or rubber dispersed in the liquid solvent so as to form a suspension. Thus, the latex is not a rubber composition which comprises an elastomer or rubber matrix in which at least one other component is dispersed. A rubber composition is in a plastic state in the raw state (non-crosslinked) and in an elastic state in the cured state (crosslinked) but in no case in a liquid state as is a latex.

Unsaturated elastomer latexes (i.e. those bearing carbon-carbon double bonds), in particular diene elastomers, are well known to those skilled in the art. They constitute in particular the elastomeric base of the RFL adhesives described in the introduction to this document.

The unsaturated elastomer of the latex is preferably a diene elastomer, more preferably a diene elastomer chosen from the group consisting of butadiene copolymers, styrene-butadiene copolymers, vinylpyridine-styrene-butadiene terpolymers, natural rubber with the exception of chlorinated natural rubber, and mixtures of these elastomers.

Advantageously, this step of depositing the aqueous adhesive composition is followed by a step of drying the CVR composite at a temperature greater than or equal to 120°. for at least 5 seconds and then by heat treatment at a temperature greater than or equal to 180°C for at least 5 seconds.

COMPOSITE GLASS RESIN

According to the invention, the composite is bonded with a layer of adhesive composition as described above.

Preferably, the CVR strand is previously adhered by a composition based on epoxy and diisocyanate blocked in aqueous solution.

PROCESS ACCORDING TO THE INVENTION

A) pre-adhesion stage

The pre-adhesion of the CVR strand(s) is carried out in a first bath based on epoxy and diisocyanate blocked in aqueous solution.

Advantageously, the epoxy compound is selected from the group consisting of diethylene glycol, diglycidyl ether, polyethylene, diglycidyl ether; polypropylene glycol, diglycidyl ether, neopentyl glycol, diglycidyl. ether, 1,6-hexanediol, diglycidyl ether, glycerol, polyglycidyl ether, trimethylolpropane, polyglycidyl ether, polyglycerol, polyglycidyl ether; pentaerythrithiol, polyglycidyl ether, diglycerol, polyglycidyl ether; sorbitol polyglycidyl ether or isosorbide diglycidyl ether and preferably is polyglycerol polyglycidyl ether.

Advantageously, the blocked diisocyanate compound is selected from the group consisting of diphenylmethane diisocyanate or polyphenylene polymethylene polyisocyanate and preferably N,N'-(methylenedi-p-phenylene)bis[hexahydro-2-oxo-1H-azepine-1-carboxamide]-4,4'-diisocyanate.

Advantageously, this pre-adhesion step is followed by a step of drying the CVR composite at a temperature greater than or equal to 120°C for at least 5 seconds, then by a heat treatment at a temperature greater than or equal to 180°C for at least 5 seconds.

B) step of depositing the aqueous adhesive composition according to the invention

The aqueous adhesive composition according to the invention is then deposited on the pre-adhered CVR strand(s).

Preferably, the aqueous adhesive composition is prepared so that the blocked diisocyanate is at a mass rate of the aqueous adhesive composition strictly less than or equal to 0.50%.

Preferably, the diisocyanate compound blocked in the aqueous adhesive composition of the second bath is at a mass rate strictly less than 0.40%, preferably less than or equal to 0.30%, more preferably less than or equal to 0.20%, more preferably less than or equal to 0.10% and even more preferably less than or equal to 0.05%.

More preferably, the aqueous adhesive composition of the second bath is free of blocked diisocyanate.

COMPOSITE ELASTOMER ACCORDING TO THE INVENTION

The invention also relates to an elastomer composite reinforced with at least one or more strands of bonded CVR Glass-Resin composite as defined above. The elastomer matrix is based on an elastomer composition comprising at least one elastomer and one other constituent.

Preferably, the elastomer composition comprises a diene elastomer. By elastomer or rubber (the two terms being synonymous) of the "diene" type, is generally meant an elastomer derived at least in part (i.e. a homopolymer or a copolymer) from diene monomers (monomers bearing two carbon-carbon double bonds, conjugated or not).

The elastomer compositions may contain a single diene elastomer or a mixture of several diene elastomers, the diene elastomer(s) being able to be used in association with any type of synthetic elastomer other than diene, or even with polymers other than elastomers, for example thermoplastic polymers.

In an embodiment preferably intended for pneumatic use, the elastomer composition comprises a diene elastomer chosen from the group consisting of polybutadienes (BR), natural rubber (NR), synthetic polyisoprenes (IR), the various butadiene copolymers, the various isoprene copolymers, and mixtures of these elastomers.

Such copolymers are more preferably selected from the group consisting of butadiene-styrene copolymers (SBR), whether the latter are prepared by emulsion polymerization (ESBR) or in solution (SSBR), isoprene-butadiene copolymers (BIR), isoprene-styrene copolymers (SIR) and isoprene-butadiene-styrene copolymers (SBIR).

Advantageously, the ethylene alpha olefin type elastomer is chosen from the group consisting of ethylene-propylene copolymers (EPM), ethylene-propylene-diene copolymers (EPDM) and mixtures of these copolymers.

Preferably, the elastomer composition comprises a reinforcing filler.

When a reinforcing filler is used, any type of reinforcing filler known for its ability to reinforce an elastomer composition suitable for manufacturing tires may be used, for example an organic filler such as carbon black, a reinforcing inorganic filler such as silica, or a blend of these two types of filler, in particular a blend of carbon black and silica.

Suitable carbon blacks are all carbon blacks conventionally used in tires (so-called tire grade blacks). For example, reinforcing carbon blacks of the 100, 200 or 300 series (ASTM grades) are particularly suitable.

In the case of use of carbon blacks with an isoprene elastomer, the carbon blacks could for example already be incorporated into the isoprene elastomer in the form of a masterbatch (see for example applications WO 97/36724 or WO 99/16600).

Examples of organic fillers other than carbon blacks include functionalized polyvinylaromatic organic fillers as described in applications WO-A-2006/069792 and WO-A-2006/069793.

By "reinforcing inorganic filler" is meant in the present application, by definition, any inorganic or mineral filler (whatever its color and origin (natural or synthetic)), also called "white" filler, "light" filler or even "non-black filler" as opposed to carbon black, capable of reinforcing on its own, without any means other than an intermediate coupling agent, an elastomer composition, in other words capable of replacing, in its reinforcing function, a conventional tire-grade carbon black. Such a filler is generally characterized, in a known manner, by the presence of hydroxyl groups (-OH) on its surface.

The physical state in which the reinforcing inorganic filler is present is immaterial, whether in the form of powder, micro-beads, granules, balls or any other suitable densified form. Of course, the term reinforcing inorganic filler also means mixtures of different reinforcing inorganic fillers, in particular highly dispersible siliceous and/or aluminous fillers as described below.

Suitable inorganic reinforcing fillers are in particular mineral fillers of the siliceous type, in particular silica (SiO ₂ ), or of the aluminous type, in particular alumina (Al ₂ O ₃ ). The silica used may be any reinforcing silica known to those skilled in the art, in particular any precipitated or pyrogenic silica having a BET surface area and a CTAB specific surface area both of less than 450 m2/g, preferably from 30 to 400 m2/g. As highly dispersible precipitated silicas (known as "HDS"), mention may be made, for example, of the silicas "Ultrasil" 7000 and "Ultrasil" 7005 from the company Evonik, the silicas "Zeosil" 1165MP, 1135MP and 1115MP from the company Rhodia, the silica "Hi-Sil" EZ150G from the company PPG, the silicas "Zeopol" 8715, 8745 and 8755 from the company Huber, the silicas with a high specific surface area as described in application WO 03/16837.

Finally, a person skilled in the art will understand that, as a filler equivalent to the reinforcing inorganic filler described in this paragraph, a reinforcing filler of another nature, in particular organic, could be used, provided that this reinforcing filler is covered with an inorganic layer such as silica, or else comprises functional sites on its surface, in particular hydroxyl sites, requiring the use of a coupling agent to establish the bond between the filler and the elastomer.

Preferably, the rate of total reinforcing filler (carbon black and/or reinforcing inorganic filler such as silica) is within a range of 5 to 120 phr, more preferably from 5 to 100 phr and even more preferably from 5 to 90 phr.

Carbon black can advantageously constitute the only reinforcing filler or the majority reinforcing filler. Of course, a single carbon black or a blend of several carbon blacks of different ASTM grades can be used. Carbon black can also be used in blend with other reinforcing fillers and in particular reinforcing inorganic fillers as described above, and in particular silica.

When an inorganic filler (for example silica) is used in the rubber composition, alone or in a blend with carbon black, its content is within a range of 0 to 70 pce, preferably from 0 to 50 pce, in particular also from 5 to 70 pce, and even more preferably this proportion varies from 5 to 50 pce, particularly from 5 to 40 pce.

Preferably, the elastomer composition comprises various additives.

The rubber compositions may also include all or part of the usual additives usually used in elastomer compositions intended for the manufacture of tires, such as for example plasticizers or extender oils, whether the latter are aromatic or non-aromatic in nature, pigments, protective agents such as anti-ozone waxes, chemical anti-ozonants, antioxidants, anti-fatigue agents or even adhesion promoters.

Preferably, the elastomer composition comprises a crosslinking system, more preferably a vulcanization system.

In the first embodiment preferably intended for pneumatic use, the elastomer composition comprises a vulcanization system.

The vulcanization system includes a sulfur donor agent, for example sulfur.

Preferably, the vulcanization system comprises vulcanization activators such as zinc oxide and stearic acid.

Preferably, the vulcanization system comprises a vulcanization accelerator and/or a vulcanization retarder.

Advantageously, the composite is such that the elastomer matrix is based on an elastomer composition comprising a crosslinking system comprising a molecular sulfur content ranging from 1 to 5 pce. By molecular sulfur, we mean sulfur from a Sn compound with n>2. Indeed, the inventors hypothesize that there is competition between adhesion by the adhesive composition and adhesion by copper and zinc sulfide dendrites. However, this competition tends to reduce the general level of adhesion. The more the sulfur content present in the elastomer matrix is reduced, the more this competition is reduced, the more the level of adhesion by the adhesive composition alone is promoted.

Very advantageously, the molecular sulfur content of the crosslinking system of the elastomer composition is less than or equal to 4 phr, preferably 3 phr and more preferably 2.5 phr. In addition to further reducing the competition between adhesion by the adhesive composition and adhesion by the copper and zinc sulfide dendrites, the storage life of the elastomer composition at room temperature is improved by avoiding the risks of pre-vulcanization which would occur if a higher sulfur content were used.

Very advantageously, the molecular sulfur content of the crosslinking system of the elastomer composition is greater than or equal to 1.5 pce, preferably 2 pce.

The sulfur level is measured by elemental analysis, using the Thermo Scientific Flash 2000 micro-analyzer. The analysis includes a sample combustion step and then a step to separate the compounds formed. Approximately 1 mg of sample is introduced into the micro-analyzer, where it undergoes a flash combustion of 1000°C under oxygen. The gases formed are then oxidized using excess oxygen and a tungstic anhydride catalyst. A reduction step by passing through copper then traps the excess oxygen and reduces the nitrogen oxides to N2 and the sulfites to sulfur dioxide SO2. The water is trapped and the N2, CO2, SO2 compounds formed are then separated on a chromatographic column and detected by a katharometer. Quantification of total sulfur is carried out by measuring the area of the SO2 peak, after calibration with standards.

All vulcanization accelerators, retarders and activators are used at a preferential rate within a range of 0.5 to 15 pce. The vulcanization activator(s) is(are) used at a preferential rate within a range of 0.5 to 12 pce.

The actual crosslinking system is preferably based on sulfur and a primary vulcanization accelerator, in particular a sulfenamide type accelerator. In addition to this vulcanization system, various known secondary accelerators or vulcanization activators such as zinc oxide, stearic acid, guanidine derivatives (in particular diphenylguanidine), etc.

Any compound capable of acting as an accelerator (primary or secondary) may be used which is capable of acting as an accelerator for the vulcanization of diene elastomers in the presence of sulfur, in particular thiazole-type accelerators and their derivatives, thiuram-type accelerators, and zinc dithiocarbamate-type accelerators. These accelerators are more preferably selected from the group consisting of 2-mercaptobenzothiazyl disulfide (abbreviated as "MBTS"), N-cyclohexyl-2-benzothiazyl sulfenamide (abbreviated as "CBS"), N,N-dicyclohexyl-2-benzothiazyl sulfenamide (abbreviated as "DCBS"), N-tert-butyl-2-benzothiazyl sulfenamide (abbreviated as "TBBS"), N-tert-butyl-2-benzothiazyl sulfenimide (abbreviated as "TBSI"), zinc dibenzyldithiocarbamate (abbreviated as "ZBEC") and mixtures of these compounds. Preferably, a primary accelerator of the sulfenamide type is used.

In the second embodiment preferably intended for belt use, the crosslinking system is substantially free of sulfur, and advantageously comprises a peroxide, preferably an organic peroxide. Advantageously, the peroxide content ranges from 0.5 to 8 pce. Advantageously, the crosslinking system comprises a co-crosslinking agent, preferably sulfur or triallylcyanurate.

BANDAGE NO PNEUMATIC ACCORDING TO THE INVENTION

The invention also relates to a non-pneumatic tire. The elastomer composite of the invention can advantageously be used for reinforcing non-pneumatic tires of all types of vehicles, in particular passenger vehicles or industrial vehicles such as heavy goods vehicles.

The invention will be better understood from reading the following description, given solely as a non-limiting example and with reference to the drawings in which:
- there is a schematic representation of the process for gluing one or more strands of CVR comprising steps of a process according to the invention; and
- there is a photograph of a strand of CVR glued according to the method of the invention and a strand of CVR glued according to the method of the state of the art.

Of course, the invention relates to the objects previously described, namely the elastomer composite such as the non-pneumatic tire comprising it, both in the raw state (before crosslinking) and in the cooked state (after crosslinking).

It was represented on the an embodiment of an installation for gluing one or more strands of CVR according to the invention, designated by the general reference 30.

The manufacturing facility 30 is capable of manufacturing one or more strands of glued CVR.

The installation 30 comprises, in the direction of travel of the CVR strand(s) in the installation 30, from upstream to downstream, means 34 for upstream storage of the CVR strands, a first aqueous pre-adherence bath 36 comprising a composition based on an epoxy compound and a blocked diisocyanate compound in which the CVR strand(s) are soaked, a device 38 for drying by heat treatment of the pre-adhered strands, a second bath 40 consisting of an aqueous adhesive composition for depositing this adhesive composition on the CVR strands, a device 42 for heat treatment of the glued CVR strands and means 44 for downstream storage of the heat-treated glued CVR.

The upstream 34 and downstream 44 storage means each comprise a storage reel for the CVR strands, enabling the CVR strands to be unwound and wound respectively.

We will now describe an example of a process for bonding one or more strands of CVR Glass-Resin composite.

In this process, a pre-adhesion step is carried out in a first bath based on an epoxy resin and a blocked diisocyanate in aqueous solution, for example based on polyglycerol polyglycidyl ether and N,N'-(methylenedi-p-phenylene)bis[hexahydro-2-oxo-1H-azepine-1-carboxamide]-4,4'-diisocyanate. The ingredients are introduced into the water with stirring, for example in the following order: 1.15 percent by weight of polyglycerol polyglycidyl ether (for example "Denacol EX-512" from Nagase Chemicals), 0.02% of zinc acetate, 0.08% of anti-foaming agent, 15.15% of a 20% solution of 4,4'-diisocyanate N,N'-(methylenedi-p-phenylene)bis[hexahydro-2-oxo-1H-azepine-1-carboxamide and 83.6% by weight of water.

To do this, several strands of CVR Glass-Resin composite are brought into contact with the first bath.

Then, the CVR Glass-Resin composite strands are dried, for example by passing through a high-frequency heating oven or tunnel (for example for 20 s at 170°C) and they undergo heat treatment (for example for 30 s at 220°C).

Next, a step of depositing the aqueous adhesive composition comprising water, a mixture of unsaturated elastomer latex and a resin based on phloroglucinol, 1,4-benzenedicarboxaldehyde and polyvinyl alcohol is carried out. The proportions of these different constituents are described below.

To do this, several strands of CVR Glass-Resin composite are brought into contact with the adhesive composition. To do this, the CVR Glass-Resin composite strand is continuously unwound from the storage reel of the storage means 34 and the CVR Glass-Resin composite strands are passed through the first bath, then they pass into a heat treatment device then into a second bath comprising the aqueous adhesive composition and they pass into a heat treatment device for example by passing through a heating oven or tunnel (for example for 20 s at 170°C) and they undergo a heat treatment (for example for 30 s at 220°C).

There represents a strand of CVR bonded by the process as described above compared to a strand of CVR bonded from the state of the art.

TESTS COMPARATIVES

These tests demonstrate that the adhesion performance on a CVR composite with an aqueous adhesive composition according to the invention is equivalent while having a better distribution of the adhesive composition on the composite compared to the composition of the state of the art as demonstrated on the and that the aqueous adhesive composition according to the invention has an improved viscosity compared to a conventional adhesive composition.

For this purpose, five aqueous adhesive compositions were prepared, one in accordance with the first embodiment of the invention (hereinafter referred to as C-2), two in accordance with the second embodiment of the invention (hereinafter referred to as C-3, C-4) and two not in accordance with the invention (state-of-the-art composition and control composition hereinafter referred to as C-1 and T-1). Their formulations (expressed as a percentage by weight) are presented in Table 1 below. The quantities listed in this table are those of the constituents in the dry state, reduced to a total of 100 parts by weight of aqueous adhesive composition (i.e. the constituents and the water).

Adhesive composition C-1 is a state-of-the-art composition based on formaldehyde and resorcinol.

Adhesive composition T-1 is a control composition based on 1,4-benzenedicarboxaldehyde and phloroglucinol.

The adhesive composition C-2 according to a first embodiment of the invention is a composition based on formaldehyde, resorcinol and PVOH.

Adhesive compositions C-3 and C-4 according to a second embodiment of the invention are compositions based on 1,4-benzenedicarboxaldehyde, phloroglucinol and PVOH.

Protocol for producing the adhesive composition

In a 250 mL flask equipped with a mechanical stirring system, compound A2 (for example resorcinol) and sodium hydroxide are introduced. Stir for 1 min to 60 min to homogenize (for example at 250 rpm). Then, compound A1 is added at 50°C (for example formaldehyde) and stirred for example for 1 min to 60 min to homogenize (for example at 250 rpm). Allow to cool then add the latex phase and compound A3 (for example PVOH) is added at 40° to help with solubilization and stir for 30 min. A mixture of the adhesive composition according to the first embodiment is then obtained.

In a 250 mL flask equipped with a mechanical stirring system, the aromatic compound A1 (for example 1,4-benzenedicarboxaldehyde) and the sodium hydroxide are introduced. Stirring is carried out for 1 min to 60 min to homogenize (for example at 250 rpm). Then, the compound A2 (for example phloroglucinol) is added and stirring is carried out for example for 1 min to 60 min to homogenize (for example at 250 rpm) at 50°C. It is allowed to cool and then the latex phase is added and the compound A3 (for example PVOH) is added at 40° to help with solubilization and stirring is carried out for 30 min. A mixture of the adhesive composition according to the second embodiment is then obtained.

At the end of this time, the aqueous adhesive composition according to the first or second embodiment of the invention is ready to be used.

By total dry extract rate of the adhesive composition is meant the ratio between the mass of residue obtained after drying of the adhesive composition and the mass of the adhesive composition before drying.

This dry extract rate is measured in accordance with standard NF EN 827 (March 2006).

Adhesive compositions T-1 C-1 C-2 C-3 C-4 1,4-benzenedicarboxaldehyde (1) 0.84 0 0 0.84
0.84 Formaldehyde (2) 0 0.54 0.54 0 0 Phloroglucinol (3) 1.59 0 0 1.59
1.59 Resorcinol (4) 0 1.88 1.88 0 0 Sodium hydroxide (5) 0.216 0.05 0.05 0.216
0.216 PVOH (6) 0 0 0.10 0.10 0.15 Vinylpyridine-styrene-butadiene terpolymer 15.37 16.04 16.04 15.37 15.37 Ammonia 0.49 0.51 0.51 0.49 0.49 Blocked caprolactam diisocyanate (7) 0 1.96 1.96 0 0 Total weight of dry extract of adhesive composition 18.5 21.0 21.1 18.6 18.7 Water weight 81.5 79 78.9 81.4 81.3 % PVOH (mass rate) 0 0 0.1 0.1 0.15 Total 100.0 100.0 100.0 100.0 100.0

1. 1,4-benzenedicarboxaldehyde (from ABCR company; 98% purity);
2. Formaldehyde (from Caldic; diluted to 36%)
3. Phloroglucinol (from Alfa Aesar; 99% purity);
4. Resorcinol (Sumitomo CHIBA)
5. Sodium hydroxide (from Aldrich; diluted to 30%);
6. PVOH (water soluble biodegradable flat film, supplied by Ecomavi).
7. DiNCO 4,4'-diphenylmethylene diisocyanate ([Grilbond IL-6 50% supplied by EMS])

Viscosity test

After preparing the various aqueous adhesive compositions, the viscosity is measured at different time intervals. The viscosity is measured using a Brookfield Viscometer type viscometer and spindles adapted to the target viscosities using the following protocol: the sample is transferred into the thermostated chamber to approximately 20 mL (inner beaker graduation) while avoiding the formation of air bubbles, the sample is allowed to regulate at the measurement temperature of 20°C for the indicated time, i.e. 1 to 20 minutes depending on the starting temperature of the composition, the speed is selected, for example 60 rpm and the spindle is started to rotate, the axis is waited for to be stabilized (1 minute) before taking the first reading and the result is read on the digital display (viscosity in cP).

Adhesion test

Different control bonded CVR Glass-Resin composite strands C1, T1, and bonded CVR Glass-Resin composite strands C2, C3 and C4 according to the invention were tested by means of a test aimed at measuring the tear force of these bonded CVR Glass-Resin composite strands embedded in an elastomeric matrix.

The CVR Glass-Resin composite strands were coated with each of the protocols described below in Table 1 below, then dried in a drying oven at 170°C for 20s. Then the adhesive composition was crosslinked by passing the CVR Glass-Resin composite strands through a treatment oven at 220°C for 30s. Then the assembly was bonded by baking to a natural rubber composition, using a vulcanization heat treatment, to form composite specimens as described below.

The quality of the bond between the rubber composition and the CVR Glass-Resin composite strands is then determined by a test in which the force required to extract sections of CVR Glass-Resin composite strands from the vulcanized rubber composition is measured. This rubber composition is a conventional composition that can be used for calendering tire carcass reinforcement plies, these plies comprising CVR Glass-Resin composite strands embedded in an elastomeric matrix based on natural rubber, carbon black and the usual additives.

More precisely, the vulcanizate is a block of an elastomeric composition consisting of two plates measuring 200 mm by 4.5 mm and 3.5 mm thick, applied one on top of the other before curing (the thickness of the resulting block is then 7 mm). It is during the production of this block that the strands of Glass-Resin CVR composite (15 sections in total) are trapped between the two plates of the elastomeric composition in the raw state, at an equal distance and leaving one end of the cable of sufficient length for subsequent traction protruding on either side of these plates. The block comprising the strands of Glass-Resin CVR composite is then placed in a suitable mold and then cured under pressure. The temperature and curing time are adapted to the target test conditions and left to the discretion of the person skilled in the art; for example, in the present case, the curing of the block is carried out at 160°C for 15 min.

After baking, the test piece thus made up of the vulcanized block and the 15 sections of CVR Glass-Resin composite strands is placed in the jaws of a traction machine adapted to allow each section to be tested in isolation, at a given speed and temperature (for example, in this case, at 100 mm/min and 20°C).

The adhesion levels are characterized by measuring the so-called tear force (denoted Fmax0) to tear the strands of Glass-Resin CVR composite from the test piece. For the tear force (Fmax0), an adhesion value of 100 was set for the control T1 which represents the conventional bonding process for glass-resin composites as described in application WO2016116457.

The results of the tests carried out on the compositions are summarized in Table 2 below.

Adhesive compositions T-1 C-1 C-2 C-3 C-4 Viscosity test Viscosity at 20°C (Cp) 2.61 3.68 21.15 7.46 22.07 Adhesion test Fmax 0 100 159 161 104 101

It is noted that the compositions according to the invention (C-2 to C-4) show an increase in viscosity compared to the resins without PVOH (T-1 and C-1) while retaining equivalent adhesion (C-3 and C-4) or even improved for C-2.

Thus, the thermosetting resin according to the invention has high adhesive properties and offers an improved viscosity compared to that of the state of the art.

The invention is not limited to the embodiments previously described.

Claims (12)

Aqueous adhesive composition characterized in that it comprises a thermosetting resin based on:
- at least one compound A1, the compound A1 comprising at least one aldehyde function;
- at least one phenol A21 compound;
- at least one polyvinyl alcohol A3; and
- at least one unsaturated elastomer latex comprising at least one elastomer selected from the group consisting of butadiene copolymers, styrene-butadiene copolymers, vinylpyridine-styrene-butadiene terpolymers, natural rubber with the exception of chlorinated natural rubber, and mixtures of these elastomers;
the content of compound A3 in the aqueous adhesive composition being at a mass rate ranging from 0.05% to 0.20%. Composition according to claim 1 in which compound A1 is formaldehyde. Composition according to claim 1 in which the compound A1 comprises at least one aromatic nucleus carrying at least one aldehyde function. Composition according to the preceding claim in which the compound A1 is chosen from the group consisting of 1,2-benzene-dicarboxaldehyde, 1,3-benzene-dicarboxaldehyde, 1,4-benzene-dicarboxaldehyde, 2-hydroxybenzene-1,3,5-tricarbaldehyde and mixtures of these compounds. Composition according to any one of the preceding claims in which the phenol compound A21 is chosen from:
- an aromatic polyphenol A2 comprising at least one aromatic nucleus carrying at least two hydroxyl functions in meta position relative to each other, the two ortho positions of at least one of the hydroxyl functions being unsubstituted;
- an aromatic monophenol A2' comprising at least one six-membered aromatic ring carrying a single hydroxyl function, with:
- the two ortho positions of the hydroxyl function being unsubstituted or;
- at least one ortho position and the para position of the hydroxyl function being unsubstituted;
- a mixture of A2 and A2'. Composition according to the preceding claim in which the aromatic polyphenol A2 is chosen from the group consisting of resorcinol, phloroglucinol, 2,2',4,4'-tetrahydroxydiphenyl sulfide, 2,2′,4,4′-tetrahydroxybenzophenone and mixtures of these compounds and preferably is phloroglucinol. Composition according to any one of the preceding claims in which compound A3 is polyvinyl alcohol. Composition according to any one of the preceding claims in which the content of compound A3 in the aqueous adhesive composition is at a mass rate ranging from 0.10% to 0.20% and preferably from 0.10% to 0.15%. Glass-Resin Composite CVR bonded with a layer of composition according to any one of claims 1 to 8. Method of bonding one or more strands of Glass-Resin composite, abbreviated to “CVR”, characterized in that it comprises the following steps:
a) a pre-adhesion step is carried out on one or more strands of CVR composite by dipping the strand(s) in a first aqueous bath comprising a composition based on:
- an epoxy compound; and
- a blocked diisocyanate compound;
b) a deposition step is carried out on the CVR composite strand(s) by dipping the CVR composite strand(s) in a second bath comprising the aqueous adhesive composition according to any one of claims 1 to 8. Elastomer composite reinforced with at least one or more strands of glued CVR Glass-Resin composite embedded in an elastomer matrix, characterized in that the strand(s) of glued CVR Glass-Resin composite are obtained by the process according to the preceding claim. Non-pneumatic tire (1), characterized in that it comprises a Glass Resin composite according to claim 9 or an elastomer composite according to claim 11.